When the first time has elapsed after the operator operates a power switch to stop power supply, an image processing apparatus forcibly stops power supply. When stopping power supply, the image processing apparatus executes hibernation processing to retract, in a secondary storage device, the stored content of a main memory used as a work area by a CPU. When the hibernation processing will be completed within a target time necessary to complete the hibernation processing and end processing of the image processing apparatus before the first time elapses, the image processing apparatus executes the end processing of the image processing apparatus and stops power supply after completing the hibernation processing; otherwise, the image processing apparatus interrupts the hibernation processing, executes the end processing of the image processing apparatus, and stops power supply.

1. Field of the Invention
The present invention relates to an image processing apparatus, control method therefor, and storage medium.
2. Description of the Related Art
Along with the development of high performance technology, current image processing apparatuses tend to take a longer startup time until they become operable after the user turns on the power switch. To solve this, there is a method of shortening the startup time by a suspend method which energizes a main memory when the user performs a power-off operation. However, when the main memory is a general DRAM or the like, the suspend method needs to continue energization, increasing standby power. A technique for reducing standby power to zero is a hibernation method. The hibernation method is a technique employed to further improve power saving performance though it takes a longer return time than that in the suspend method. For example, Japanese Patent Laid-Open No. 2002-73220 discloses a technique of assigning a physical power switch (toggle switch) having an OFF/ON state as the hibernation function. Japanese Patent Laid-Open No. 11-3151 discloses a technique of performing a hibernation operation when the battery is running out. At this time, even if the battery runs out, this technique avoids power-off during the hibernation shift.
However, the conventional techniques have the following problems. For example, in Japanese Patent Laid-Open No. 2002-73220, the power switch of the image processing apparatus is a (toggle) switch having a physical OFF/ON state, so the OFF/ON state of the switch and the power OFF/ON state of the main body need to coincide with each other. That is, a state in which the power supply of the main body remains ON though the switch is OFF should not occur. To prevent this, when the power switch is turned off, a protection timer needs to be set in the power supply device separately from software control to guarantee that the power supply will be turned off without fail after a predetermined time. However, when the power switch is assigned as the hibernation function, if hibernation shift processing is not completed in time, the power supply is forcibly turned off based on the protection timer during the hibernation shift.


A method for the overload protection of devices which cannot endure continuous running on account of heat loss, to avoid a complex, cost-intensive direct coupling of the device to be protected to a temperature measuring element. The inside temperature within the housing of the device is merely measured and, on the basis of device-specific characteristics stored in an evaluation circuit, a permissible operating period assigned to the inside temperature is calculated. The permissible operating period is then used as a basis for the preset operating period cycle time.

The present invention relates to a method for the overload protection of devices which cannot endure continuous running on account of heat loss, having a temperature-dependent resistor measuring the inside temperature of the device and having an evaluation circuit.
In the case of devices which may not be operated uninterruptedly, for example for reasons of heat development, an overloading of the devices must be prevented by suitable measures. For this purpose it is known from German Patent Document DE 32 48 217 A1 to measure the inside temperature of the device in the exhaust airstream of the device with a temperature-dependent resistor, which is part of an evaluation circuit and which, upon corresponding actuation, reduces the motor output to a lower value to avoid overheating.
Generally known measures for overload protection also comprise running time counters, bimetal switches or temperature measuring elements arranged directly in the device on its critical components reducing heat loss.
It may be considered disadvantageous in the case of these known measures that there is not optimum utilization of the devices--running time counter without reference to the temperature--or that there are high costs due to additional lines of the temperature measuring point and that the installation of a bimetal switch or a temperature measuring element directly in the device is complex.
An object of the invention is to provide a method for overload protection of devices which cannot endure continuous running on account of heat loss.
This and other objects are achieved by the present invention which provides a method for the overload protection of devices which cannot endure continuous running on account of heat loss, having a temperature-dependent resistor measuring the inside temperature of the device and having an evaluation circuit. The method includes measuring by means of the resistor arranged outside the device and remote from its device parts producing heat loss the inside temperature inside a housing enclosing the device. A temperature difference assigned to the inside temperature is read out from a device-specific characteristic stored in the evaluation circuit. The difference T.sub.u =.nu..sub.u -.DELTA.T is then formed in a subtracter of the evaluation circuit. From a further device-specific characteristic stored in the evaluation circuit a permissible operating period of the device is read out. This permissible operating period is assigned to the temperature difference. A preset operating period cycle time is determined using the permissible operating period as the basis for a preset operating period cycle time. After reaching the permissible operating period, the device is turned off by the evaluation circuit during the operating period cycle time.
The objects are also achieved by another embodiment of the present invention which provides a method for the overload protection of devices which cannot endure continuous running on account of heat loss, having a temperature-dependent resistor measuring the inside temperature of the device and having an evaluation circuit. The method includes measuring by means of the resistor arranged outside the device and remote from its device parts producing heat loss the inside temperature inside a housing enclosing the device. From a device-specific characteristic stored in the evaluation circuit, which characteristic is derived from device-specific characteristics, a permissible operating period of the device that is assigned to the inside temperature is read out. The permissible operating period is used as the basis for determining a preset operating period cycle time. After reaching the permissible operating period, the device is turned off by the evaluation circuit during the operating period cycle time.
In particular, with the method of the present invention, the device is utilized optimally with respect to its operating period cycle time and also, there is no need for a cost-intensive, direct coupling of the temperature measuring element in the device to its critical components producing heat loss.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

Method for the overload protection of devices which cannot endure continous running on account of heat loss


A method of routing signals within a semiconductor memory device includes providing a semiconductor wafer having a top surface with a center portion, an edge portion and wafer bond pads at the center portion. A redistribution layer is provided on the top surface of the semiconductor wafer. The method includes redistributing signals from the wafer bond pads to redistribution edge pads utilizing the redistribution layer, and routing signals from the semiconductor wafer up to the redistribution layer and routing these signals back down to the semiconductor wafer.

The present invention relates to a semiconductor device having a redistribution layer. More particularly, the redistribution layer of the semiconductor device includes a signal routing line.
Many semiconductor devices utilize wafer level packaging in integrated circuits. With wafer-level packaging, fabrication of the semiconductor device typically includes device interconnection and device protection processes, including a passivation layer over the silicon die. Bond pads typically extend out through the passivation layer for interconnection with other components of an application.
Within such processes, redistribution layers are widely used to redistribute these bond pads from one location to another. In many instances, the redistribution layer is an inexpensive way to adapt one particularly configured silicon die to several different packaging applications and assembly scenarios. Redistribution layers can therefore provide flexibility to customize a particular silicon die to various applications.
Typically, a redistribution layer is formed on top of the final passivation layer of the silicon die by relatively inexpensive processes. For example, this may be accomplished using standard photolithography and thin-film deposition techniques and electroplating. With redistribution layers, wide metal lines redistribute bond pad signals of the original silicon die, which are typically located in the center of the die, to new locations which are more convenient for the specific application, typically along the edge of the die. Typically, a redistribution layer is added to a chip after the chip is fabricated, and thus, a redistribution layer is not typically involved in the design of the internal interconnection of the chip.
For these and other reasons, there is a need for the present invention.

This patent is subject to a terminal disclaimer.


The invention relates to a multipoint focus detection device and is to provide a device which determines a sampling point of an output of a sensor in accordance with a movement speed distribution of an image on the sensor and carries out an appropriate process in case that the movement speed is different.

1. Field of the Invention
This invention relates to a focus detection device for use in a Camera or the like which uses a light beam transmitted through an imaging optical system to detect the imaged state thereof.
2. Related Background Art
In a focus detection device of the phase difference detection type, a method of correcting the distortion of the distribution of the quantity of light projected onto a photoelectric conversion element by calculating the output of the photoelectric conversion element is disclosed, for example, in Japanese Patent Application Laid-Open No. 62-173412. This example discloses a calculating method which relates distortion occurring to a secondary object image to a corrected image, and processes an image signal after A/D-converted by a predetermined calculating method shown in this publication, and returns the distortion to its original state, whereby it can accurately effect the determination of the in-focus of an objective lens.
However, depending on an optical system adopted in the focus detection device, there is a case where the movement speed of the image resulting from the defocus of the objective lens differs depending on the position on a focus detection area and as the result, the detection of the defocus amount is not accurately effected. Accordingly, accurate focus detection cannot be accomplished simply by correcting distortion by the method as described above.


A hydraulic bearing with biaxial damping with an axial and radial damping characteristics essentially independent of one another. The hydraulic bearing including a housing and an axially and radially operating elastomeric damping arrangement received therein. Several chambers are adapted to receive a hydraulic damping device and formed, with respect to the axial and radial orientation of the bearing, in pairs, with each chamber pair interconnected by at least one channel. The upper housing section is constructed as a support body including an inner core, and the outer wall of the upper housing section radially separated from the inner core, and a spring connected with the inner core and the outer wall by vulcanization. The hydraulic bearing is modular, wherein the chambers affecting the radial damping are part of a bush bearing which is inserted in the support body as a separate component and non-positively and/or positively connected thereto.

The invention relates to a hydraulic bearing, or elastomeric support, which is provided with hydraulic damping through an arrangement of chambers that receive damping means, wherein at least two chambers are always interconnected by at least one channel. More particularly, the invention is directed to a hydraulic bearing with biaxial damping configured to dampen both axial as well as radial vibrations introduced in the mount.
Different designs of elastomeric bearings or rubber mounts are used for damping vibrations transmitted between connected parts of an assembly. (The terms "support", "mount" and "bearing" will be used interchangeably in the context of the present specification and claims). Such bearings are used in large quantities particularly the automotive industry where they are employed, for example, as bearing bushings in the steering column linkage or as support for other chassis parts. Such bearing bushings are predominantly constructed to dampen radially introduced vibrations. Conversely, bearings with predominantly axial damping characteristics are employed, for example, as engine mounts for supporting the engine of the motor vehicle. Since it is desirable to further improve the driving comfort, in particular with respect to annoying vibrations and noise, simultaneous damping of radially introduced vibrations has become increasingly important in the engine mounts that were originally designed mainly for axial damping. Accordingly, biaxial bearings providing excellent damping characteristic for both axial and radial vibrations have been developed.
In particular, elastomeric bearings are frequently provided with hydraulic damping for damping vibrations with large amplitudes. To this end, at least two chambers receiving damping means are arranged in the body of the elastomeric bearing and interconnected by a channel formed in the bearing. In bush bearings, corresponding chambers are arranged in the radially outer regions of the bearing body and distributed along its circumference, whereas in axially damping bearings, the chambers are superpositioned in the axial direction.
However, hydraulic bearings with biaxial damping with a hydraulic component for both the axial damping direction and the radial damping direction are known in the art. Such hydraulic bearings with biaxial damping are disclosed, for example in DE 100 37 954 A1 and DE 103 34 901 A1. The bearings are constructed such that their elastomeric support spring simultaneously forms a part of an axially damping bearing as well as of a radially damping bearing. All the working chambers, namely the chambers for the axially damping bearing and the chambers for the radially damping bearing as well as the elastomeric support spring, form a one-piece component. However, this approach has the disadvantage that parameters which are important for the functionality in both damping directions (axial and radial) are directly dependent of one another and cannot be specified separately due to the one-piece design. In fact, any change in a desired axial damping characteristic of the elastomeric bearing body directly affects also its radial damping characteristic, and vice versa.


An example sexual aid apparatus is disclosed. In an embodiment, the sexual aid apparatus includes an electro-mechanical device configured to operate according to a control pattern to facilitate the achievement of an orgasm within a user during a session and transmit a device state. The apparatus also includes a sensor configured to measure physiological data of a user during use of the electro-mechanical device. The apparatus further includes a control engine configured to receive the physiological data from the sensor and the device state from the electro-mechanical device and determine an adjustment to the control pattern based on the physiological data from the sensor and the device state. The control engine is also configured to transmit signals related to the adjusted control pattern to the electro-mechanical device causing the electro-mechanical device to operate according to the adjusted control pattern.

Powered sexual aid devices have been around for decades. Otherwise, known as vibrators, personal massagers, cock rings, and dildos, these devices are designed to facilitate and enhance sexual pleasure when used by an individual or group of individuals. Generally, these devices are relatively simple. For example, some devices may simply have an off/on switch. Other devices may include control functions that change an amplitude or frequency of motor vibrations based on input from a user. More recently, some devices use information from physiological sensors to adjust the amplitude or the frequency of the motor.
Regardless of the level of complexity, these known sexual aid devices are reactive and impersonal. Despite significant resources dedicated to research, the exact nuances of human sexual behavior is still relatively unknown. It is generally agreed that every person has their own sexual arousals based on a complex combination of certain environmental stimuli and personal experiences/feelings. In addition to this, a person's arousals may change periodically/frequency based on mood, environment, and/or general disposition.
It is no wonder that sexual aid devices with the above described limited functionality often leave users feeling frustrated, unaroused, or incomplete. One can imagine a new user of a sexual aid device spending many intimate (and oftentimes frustrating) moments trying to find the right setting or settings on the device to enhance sexual pleasure or bring about an orgasm. Once the user finds a setting that provides the greatest pleasure (or orgasm), the user oftentimes believes the same setting will work in all instances. However, that is not always the case, which can leave the user feeling even more frustrated. For example, the same setting may not generate the same level of sexual arousal or orgasm if the user is stressed, tired, or using the sexual aid device with a partner. In many such cases, fulfillment of users' sexual desires remains as elusive as it does without the use of sexual aid devices.

Sexual aid device feedback methods and apparatus


A system is disclosed for rapidly restoring ventilatory drive to an anesthetized patient after surgery. The end-expired carbon dioxide partial pressure is used as feedback to determine the amount of CO.sub.2 to be added to the inspired breathing mixture of the patient's breathing circuit. The CO.sub.2 added to the patient's breathing circuit increases CO.sub.2 within the blood stream to a level sufficient to stimulate the central ventilatory center in the brain, thereby rapidly restoring ventilatory drive to the patient.

Anesthesia is the loss of sensation in the body induced by the administration of a drug. There are many risks associated with the drug-induced loss of sensation and without proper equipment and skilled operators, complications often occur. Because there are risks associated with anesthesia, it is preferable that an anesthetized patient emerge from anesthesia and that ventilatory drive be restored as soon as possible.
The ability of patients to breathe on their own upon emergence from anesthesia is dependent upon three conditions. First, the blood concentration of anesthetic agent must be low, less than about 0.2% for isoflurane. This is achieved by turning off the anesthetic agent, washing the agent from the breathing circuit, and ventilating the patient with a normal minute volume for several minutes. "Minute volume" is the total volume of gas delivered to or expired by a patient over one minute. Hyperventilation can be used to accelerate the process of removing the anesthetic agent from the body. However, hyperventilation causes CO.sub.2 to be expired from the lung and lowers the partial pressure of CO.sub.2 (PCO.sub.2) in the blood, P.sub.a CO.sub.2 (arterial blood carbon dioxide tension).
Second, if a neuromuscular function blocking drug had been used, it must be adequately reversed for sufficient ventilatory muscle strength to return. This is accomplished pharmacologically.
Third, the P.sub.a CO.sub.2 must be high enough to adequately stimulate the central ventilatory center in the brain. The ventilatory response to CO.sub.2 is a continuous function, but, a P.sub.a CO.sub.2 between 35 mmHg and 44 mmHg is normally required to stimulate ventilatory efforts in the patient recovering from anesthesia.
Unfortunately, increasing P.sub.a CO.sub.2 by hypoventilation can lead to complications such as hypoxia. Also, the awakening process is actually prolonged by the failure to remove anesthetic agent from the patient's body. Thus, the clinician is faced with a dilemma; the clinician must both remove the anesthetic agent by hyperventilation and increase the arterial blood carbon dioxide tension, P.sub.a CO.sub.2, by hypoventilation.
Some anesthesia machines have been manufactured with a valve that allows bypassing the CO.sub.2 absorber in a circle system breathing circuit. Bypassing the CO.sub.2 absorber permits the patient to rebreath expired CO.sub.2 gases thus the PCO.sub.2 rises in the inspired gas. However, this does not substantially hasten awakening because if the system is mostly closed, anesthetic agent is also recirculated to the patient. Therefore, even though the patient is able to rebreath expired CO.sub.2 and thereby increase the arterial blood carbon dioxide tension, the patient also rebreaths expired anesthesia agent. If the system was mostly open, little rise in PCO.sub.2 can be achieved. Also, such a design requires the clinician to remember to shut off the bypass, before the next procedure. Failure to turn off the bypass, however, was not an infrequent occurrence and occasionally contributed to complications.
In order to increase the P.sub.a CO.sub.2 of a patient, it is helpful to measure P.sub.a CO.sub.2. While measurements of CO.sub.2 from the expired breathing gas have long been used to estimate the P.sub.a CO.sub.2, this information has not been used to rapidly restore ventilatory drive to a patient after anesthesia. The gas at the end of each tidal ventilation is assumed to be in equilibrium with the arterial blood. Hence, the end-tidal CO.sub.2 partial pressure, P.sub.ET CO.sub.2, is often used to estimate P.sub.a CO.sub.2. For example, U.S. Pat. No. 4,423,739 to Passaro et al. discloses an apparatus for determining the partial pressure of CO.sub.2 in the arterial blood of a patient by measuring carbon dioxide concentration at the end-tidal of a patient's exhaled breath.
The practice of using the partial pressure of CO.sub.2 in the arterial blood of a patient to control respiration has been in use for several years. For example, U.S. Pat. No. 4,112,938 to Jeretin discloses a device for controlling patient respiration in accordance with the partial pressure of CO.sub.2 in the arterial blood or tissue measured in the alveolar expiration air. The Jeretin patent states that low arterial CO.sub.2 content resulting from hyperventilation is brought to a standard value by increasing CO.sub.2 content in the inspiration air. The CO.sub.2 in this system comes, however, from the patient's own expired gas, not from an external source. Control of this process is based on a continuous measuring of the partial pressure of CO.sub.2. The serious problems associated with anesthesiology and in particular restoring the ventilatory drive of a patient are not addressed by the Jeretin patent.
Previous attempts to restore the ventilatory drive to an anesthetized patient involves such things as bypassing the CO.sub.2 absorber. This technique, while partially effective in raising the CO.sub.2 in the inspired mixture has the problem of reintroducing the anesthesia agent to the patient. For example, in the Jeretin device, the patient rebreathes anesthetic agent as well as the CO.sub.2. Such a process inhibits resuscitation of the patient. It is one object of the present invention to solve this problem. Furthermore, as rebreathing limits the inspired PCO.sub.2 to the patient's mean expired PCO.sub.2, the CO.sub.2 concentration may not be high enough to raise the P.sub.a CO.sub.2 to the desired level rapidly and reliably. It is the object of the present invention to also solve this problem. Yet another object of the invention is to provide a system which is automated to enable effective emergence from anesthesia while minimizing the risk of operator error. It is yet a further object of the invention to optimize the introduction of CO.sub.2 to a patient to minimize risks and complications associated with prolonged anesthesia.

Rapid anesthesia emergence system using closed-loop PCO.sub.2 control


Methods, apparatus, systems and articles of manufacture are disclosed to recycle 3D build material including a 3D printer having a build platform, a vibration generator to alternately apply a first vibration mode to the build platform to move build material on the build platform in a first direction, and to apply a second vibration mode to the build platform to move the build material in a second direction and an air handler to generate an airflow to remove the build material from the build platform.

Some three-dimensional (3D) printers deposit successive layers of a 3D build material (e.g., a nylon powder, a metal powder, etc.) and fuse or bond selected portions of the 3D build material for each layer by applying energy, such as electromagnetic energy, or a reactant, such as a binder, to the layer of the 3D build material. This assembly process continues, layer-by-layer, until the entire 3D product is completed. When the 3D product is complete, unused build material may be removed and recycled to some extent.
The figures are not to scale. Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts.

Method and apparatus to recycle 3D build material

Hewlett-Packard Development Company, L.P.


An adapter for facilitating the portability of satellite antennas includes a first side adapted for attachment to a satellite base and a second side adapted to releasably engaging a base unit. A plurality of base units are typically attached to desired locations for the satellite antenna, such as a home, recreational vehicle, cabin or boat. By simply releasing the adapter from the base unit, the satellite antenna may be conveniently moved to another desired location. To further facilitate transport, the receiver arm of the satellite antenna can be modified to readily fold inwardly with the release of a pin.

1. Field of the Art
The present invention relates to an apparatus and method for use with a base unit and a compact satellite antenna to enable the satellite antenna to be conveniently moved and mounted between a home and other places of use such as cabins, boats and recreational vehicles. In particular, the present invention relates to an adapter which enables the quick release and mounting of the base of such a satellite antenna to a base unit secured on a building, boat or vehicle.
2. State of the Art
The use of satellite dishes has become increasingly common over the last two decades. While the dishes used to be large and infrequently used, technology has decreased the size of the satellite dishes and significantly increase the amount of information which may be obtained with a satellite dish. One area which has experienced especially significant growth has been the use of satellite dishes to receive entertainment programming. Although satellite dishes have traditionally been expensive, the dishes are advantageous in that they avoid the need to run cables and can therefore be used in even very remote locations.
Until recently, most satellite dishes measured five or six feet across and were not readily moveable. However, recent advances in commercialized technology have lead to explosive growth in small digital satellite dishes, commonly referred to as digital satellite systems or "DSS". The DSS dishes typically measure 18 inches to two feet across and can be easily lifted by an adult. The DSS antennas are particularly advantageous in that they may be mounted on the sides of buildings or even on balconies, as opposed to the considerable space occupied by their predecessors. The decrease in size also brought the cost of such devices down to a level which is economically feasible for most families. Instead of selling for three to four thousand dollars, as had the large dishes, the small digital satellites typically sell for seven to eight hundred dollars.
Referring now to FIG. 1, there is shown a perspective view of a DSS antenna, generally indicated at 4. The antenna 4 includes a dish 10, its accompanying receiver arm 20 for holding a receiver 24, and support arm 30. The dish 10 is typically attached to the side of a house, etc., by four bolts 40 which extend through a base plate 50 at the bottom of the support arm 30. The bolts securely hold the base 30, and thus the dish 10, to prevent the antenna 4 from being damaged during storms and the like. Thus, the bolts must be firmly anchored in a mounting surface 60, such as a roof. A cable 70 carries the received signals to a processing module (not shown) and then on to the television set (not shown).
Due to the significant improvements achieved by the DSS antennas, many users desire to use the dishes to receive entertainment programming in locations other than their homes. For example, many people who own recreational vehicles such as motor homes desire to receive the programming available over the DSS antenna. However, prior to the present invention, the use of the DSS antennas on motor homes raised two significant concerns. First, a second antenna must be purchased. While the price of the antenna is significantly less than the large dishes previously available, purchasing the second antenna and having it mounted on the motor home can still cost nearly a thousand dollars. Second, the DSS antenna creates a significant amount of drag on the recreational vehicle when moving. Therefore, the antenna should be removed prior to driving the recreational vehicle. However, if the satellite base is boltedly attached to the vehicle, removal of the DSS antenna can be difficult and can consume a considerable amount of time.
Several inventions have been made to reduce the drag created by the antenna. For example, in U.S. Pat. No. 4,811,026, there is shown a satellite antenna which can be compacted for traveling. While such an antenna reduces drag, it is more expensive than a standard antenna and still requires the purchase of a separate antenna for the recreational vehicle.
The cost and lost time of removing the DSS antenna from the motor home is equally applicable to cabins, houseboats, and other watercraft. While the DSS antenna will generally not create a significant amount of drag at the speeds commonly traveled by boats, most owners will desire to remove the DSS antenna when the boat is not in use in order to prevent theft.
Thus, there is a need for an adapter which enables the base plate 50 of the support arm 30 of the satellite antenna 4 to be conveniently attached and detached from a base unit mounted on a house, a cabin, a recreational vehicle or a boat. Such a base would typically include a rotatable member which allows the user to position the satellite in a desired direction.
Such an adapter should enable the user to use a single DSS antenna at his or her home, at a cabin, on a recreational vehicle and on a boat. To move the DSS antenna, the adapter need only be removed from the base unit it is mounted on, and slid into a similar base unit disposed on the recreational vehicle, boat, etc. If travel is involved prior to use, the DSS antenna should be storable in the boat or recreational vehicle until arrival at the desired location.
Furthermore, such an adapter should be attachable to a base unit on a boat or recreational vehicle which is rotatable. Such a base unit would enable the DSS antenna to be rotated until the dish is disposed in the desired orientation.

Apparatus and method for improving portability of satellite antennas


Magnesium hydroxide slurries having the following characteristics: (i) having a solids content of between 40-80 wt. % based on the weight of the slurry with the balance being water; (ii) containing between 0.01-5.0 wt.% of at least one viscosity modifying agent or dispersant based on the weight of the slurry selected from the following groups: (1) inorganic acids having a molecular weight less than 130 amu and their inorganic salts excluding H.sub.2 SO.sub.4, H.sub.3 PO.sub.4, silicic acid and salts having an alkali metal as sole cation; (2) low molecular weight (i.e. less than 200 amu) carboxylic acids optionally containing one or more hydroxyl groups and their inorganic salts excluding salts having alkali metal as sole cation; (3) polyhydric alcohols or carbohydrates containing two or more hydroxyl groups and having a molecular weight less than 500 amu; and (4) alkaline earth oxides and/or hydroxides; (v) being sedimentation stable for at least seven days without substantial agitation; and (vi) maintaining a viscosity of less than 1000 cP at a shear rate of 139 sec.sup.-1 over a period of at least seven days.

Magnesium hydroxide slurries may be produced from magnesia (MgO) as a feed stock. Magnesia may be obtained from the natural mineral magnesite (MgCO.sub.3) or from sea water or brine. Production of magnesium hydroxide from magnesite generally involves calcination to decompose MgCO.sub.3 to MgO with subsequent hydration in water to convert MgO to Mg(OH).sub.2. The production of magnesium hydroxide from sea water or brine entails direct precipitation with quicklime (CaO) or more preferably with dolime or dolomitic lime. Commercially this is usually a precursor to the production of "synthetic magnesia" by subsequent calcination of the precipitated magnesium hydroxide. The sea water is seeded with magnesium hydroxide to promote crystal growth and to improve settling and filtering characteristics of the magnesium hydroxide precipitate. A flocculating agent is also usually added. The resulting thickened slurry is vacuum-filtered to produce a filter cake containing about 50% magnesium hydroxide. Because nearly all the magnesium hydroxide produced in this way is presently calcined to MgO, the characteristics of the magnesium hydroxide precipitate are optimised for solid/liquid separation rather than for magnesium hydroxide production.
Conventional magnesium hydroxide slurries may be utilised for desirable applications which include:
(a) use in relation to treatment of industrial effluent or waste water; PA1 (b) use as a commercial alkali for pH control; PA1 (c) flue gas desulphurisation; and PA1 (d) use of adsorptive properties of magnesium hydroxide to remove inorganic or organic contaminants. PA1 (a) JP 5-279017 and JP 5-279018 which describe a hydration process of light burned magnesia which is introduced into a hydration tank equipped with a stirrer or agitator and which is simultaneously milled by steel balls or other form of abrading apparatus; PA1 (b) JP-2-48414 which refers to a process of producing magnesium hydroxide as a hexagonal plate like crystal having a specific surface area (SSA) of 10m.sup.2 /g or less. A slurry of Mg(OH).sub.2 having a solids content of 5-70% wt % is formed as an intermediate in a hydration process at above 50.degree. C. under agitation and some slurry is periodically removed and replaced by hot water and magnesia to obtain a uniform slurry density. This slurry is used for producing high purity dry Mg(OH).sub.2 used for flame retardant applications; PA1 (c) JP-01-212214 refers to a method of manufacture of magnesium hydroxide wherein magnesia having a mean particle diameter of less than 100 micron is hydrated in the presence of alkali metal ions and/or alkaline earth metal ions and also in the presence of the hydroxide ion, nitrate ion, carbonate ion, chloride ion and/or sulphate ion. The magnesia is initially calcined between 400-850.degree. C. before being pulverised. A slurry is formed having 10-50% wt % Mg(OH).sub.2 ; PA1 (d) JP 3-252311 refers to a process for preparing "active" magnesium hydroxide wherein light burnt magnesia is obtained by calcining a natural magnesite at 850-1100.degree. C. and subsequently grinding the magnesia to a mean particle size of 5-10 micron and then subjecting the ultra-fine powder in an "acidic reaction" to obtain active magnesium hydroxide; PA1 (e) Bron et al., Chemical Abstracts (CA) 68(2): 5884e (1966) refers to the hydration of magnesite derived MgO. Magnesium hydroxide was produced during boiling or short wet grinding of the MgO with water in a ball mill and had a characteristic brucite structure consisting of hexagonal laminar crystals; PA1 (f) JP 54150395 which refers to production of magnesium hydroxide slurry by grinding dried magnesium hydroxide to a specified particle size and then mixing with water under agitation; PA1 (g) EP 0599085 which refers to an apparatus and method for the production of active magnesium hydroxide. In this specification coarse light burned magnesia is comminuted in the wet state with a wet-pulveriser and hydrated in the presence of an alkaline aqueous medium which included sodium hydroxide at an elevated temperature of not less than 70.degree. C. The resultant pulverised material is classified into fine and coarse particles using a classifying means which is generally set to restrict the passage of particles in excess of 20 micron. Subsequently the coarse particles are recycled to the wet-pulveriser. By subjecting light burned magnesia to concurrent wet-pulverisation and hydration in the presence of a heated alkaline aqueous medium, magnesia can be simultaneously comminuted and hydrated under rapid heating to produce an active magnesium hydroxide showing a low viscosity even at a high concentration; PA1 (h) KR 9301256 which describes formation of active magnesium hydrate made from light burned magnesite which is subjected to wet crushing with water, an alkali stabiliser inclusive of sodium hydroxide and dispersing agent inclusive of polycarboxylate using reaction heat and crushing heat; PA1 (i) DD 272288 which describes hydration of MgO resulting from MgCl.sub.2 thermal decomposition which is carried out by (a) pre-hydrating MgO in one or more series or parallel connected hydration reactors; and (b) grinding in one or more series or parallel connected hydration reactors; and PA1 (j) JP 03-60774 which refers to the production of magnesium hydroxide slurries which includes the step of slaking finely pulverised light burnt magnesia which is obtained by firing naturally produced magnesite with water with heating to 85-100.degree. C. Sodium hydroxide is added as a hydration accelerator. PA1 (A) high-solids-content, to allow high reaction capacity per unit (weight or volume) of slurry; PA1 (B) high reactivity; PA1 (C) stability to both settling and ageing; and PA1 (D) low viscosity to enable the slurry to be transported, sprayed, coated, (slip) cast and/or dosed by conventional pumping techniques. PA1 (i) having a solids content of between 40-80 wt % based on the weight of the slurry with the balance being water; PA1 (ii) containing between 0.01-5.0 wt % of at least one viscosity modifying agent or dispersant based on the weight of the slurry selected from the following groups: PA1 (iii) being sedimentation stable for at least 7 days without substantial agitation; and PA1 (iv) maintaining a viscosity of less than 1000 cP at a shear rate of 139 sec.sup.-1 over a period of at least seven days. PA1 (i) subjecting calcined magnesia of a particle size of about or less than 25 mm to a first particle reduction zone wherein said calcined magnesia is mixed with water and ground; PA1 (ii) passing said finely divided material through a screening means to ensure passage therethrough of finely divided magnesia having a particle size of about 2 mm or less and returning oversize magnesia particles to said first reduction zone; PA1 (iii) hydrating said finely divided magnesia in a hydration zone wherein said finely divided magnesia is mixed with water under agitation and heat so as to produce a magnesium hydroxide slurry having at least 80% hydration; PA1 (iv) passing said slurry though a second particle reduction zone so as to produce slurry particles wherein 90% of said slurry particles have a size of less than 50 microns; PA1 (v) adding a viscosity modifying agent selected from groups (1), (2), (3) and (4) prior to or during steps (i), (ii), (iii) or (iv) so as to ensure a maximum viscosity of 1000 cP; and PA1 (vi) obtaining after step (v) as a final product stable, pumpable, magnesium hydroxide slurries having a solids content of at least 40%. PA1 (i) continuously feeding magnesia to a hydration zone wherein the slurry is subjected to continual agitation; PA1 (ii) hydrating said magnesia in the hydration zone under agitation and heat so as to produce a magnesium hydroxide slurry having at least 80% hydration; PA1 (iii) adding a viscosity modifying agent selected from groups (1), (2), (3) and (4) prior to or during steps (i), (ii) or (iii) so as to ensure a maximum viscosity of 1000 cP; and PA1 (iv) obtaining as a final product stable, pumpable magnesium hydroxide slurries having a solids content of at least 40%. PA1 (1) inorganic acids having a molecular weight less than 130 amu and their inorganic salts excluding H.sub.2 SO.sub.4, H.sub.3 PO.sub.4, silicic acid and salts having an alkali metal as sole cation; PA1 (2) low molecular weight (i.e. less than 200 amu) carboxylic acids optionally containing one or more hydroxyl groups and their inorganic salts excluding salts having alkali metal as sole cation; PA1 (3) polyhydric alcohols or carbohydrates containing two or more hydroxyl groups and having a molecular weight less than 500 amu; and PA1 (4) alkaline earth oxides and/or hydroxides.
In this context magnesium hydroxide slurries are preferred for use in applications such as (a) (b) (c) and (d) above rather than magnesia either to avoid complications that uncontrolled hydration can cause, such as heat generation and cement formation, or because conversion of MgO to Mg(OH).sub.2 is essential to the desired application. In this regard magnesia in its reactive form in an aqueous environment will become hydrated to Mg(OH).sub.2 relatively spontaneously and in some cases it is desirable to control the rate of hydration dependent upon the desired application.
Magnesia in its reactive form commonly known as caustic magnesia, caustic calcined magnesite or light burned magnesia has to be distinguished from a relatively inert form of magnesia known as dead burned or inert magnesia.
None of the commercially produced magnesium hydroxide slurries which have a relatively high solids content (i.e. 50-60 wt %) have been found to have a combination of high solids content, stability to settling and high overall reactivity which are characteristics of magnesium hydroxide slurries produced by the present invention as hereinafter described. It is common practice in some conventional slurries, as referred to in prior art hereinafter, to incorporate a polymeric viscosity modifying agent to thin and/or stabilise the slurry but this practice has undesirable side effects as described hereinafter.
Reference also may be made to conventional processes for producing magnesium hydroxide slurries which are described in the following patent specifications:
It is known from JP 5-208810 and JP 3-252311, for example, that magnesia may be produced by calcination of magnesite followed by particle reduction to obtain ultra-fine particles having a mean particle size of 5-10 micron which is then hydrated to form a magnesium hydroxide slurry. The hydration process can be carried out in a particle reduction zone.
It is also known to add viscosity modifying agents or dispersants to the slurry to control viscosity or dispersability of the end product. Such viscosity modifying agents or dispersants can include. decomposable phosphates (see FR 2399485); carboxylic acid type polymeric surfactants (see JP 5-208810); polyanion and anion of strong acids such as HCl, H.sub.2 SO.sub.3 or H.sub.2 SO.sub.4 (see DE 4302539); polymeric anion dispersant and water soluble alkali metal salt (AU 48785/93); sulphomethylated acrylamide homopolymers or copolymers (see U.S. Pat. No. 4,743,396); alkaline salts of a sulfosuccinic ester product (see DE 3323730); alkali metal silicate and hydroxide and/or mineral acid salts (see J62007439); organic or inorganic dispersants (see J61270214); xanthan gum and lignin sulphonates (see CA 110 (10):7837e); carboxymethylcellulose (see CA 104 (6):39729k); cationic polymers (see U.S. Pat. No. 4,430,248); ferrous hydroxide or aluminium hydroxide (see CA 79(8):44013S) and polyacrylates (see U.S. Pat. No. 4,230,610).
It is also known to use additives to accelerate the hydration of MgO to Mg(OH).sub.2 and/or to modify the crystal shape of the magnesium hydroxide product during hydration. Such additives include citric acid or magnesium chloride (see CA 110(24):215623f), short chain carboxylic acids or corresponding salts such as magnesium acetate (see JP 3-197315, JP 01-131022 and DD 280745), ammonium chloride (see DD 241247); magnesium chloride, magnesium acetate, magnesium sulphate or magnesium nitrate (see DD 246971); inorganic or organic acids such as HCl or acetic acid or their magnesium salts such as magnesium chloride, or magnesium acetate (see CA111(18):159019n), proprionic acid (see JP 63-277510), n-butyric acid (see JP 63-277511), and sodium hydroxide (see JP 03-60774).
In particular, reference should be made to JP-3-197315, which refers to the production of a magnesium hydroxide slurry having 3-70 wt % and more preferably 20-50 wt % solids as an intermediate in the production of magnesium hydroxide crystals having hexagonal plate-like crystals which are obtained as a final product of the hydration of magnesia. These crystals are utilised as a fire retardant. JP-1-131022, which is discussed in the prior art preamble of JP-3-197315, states that the purpose of addition of magnesium salts such as magnesium acetate or organic acids such as acetic acid, is for controlling the rate of hydration or for controlling the growth of magnesium hydroxide crystals. The crystals that are obtained by the hydration process of this reference are regular in shape thereby avoiding the formation of agglomerates.
In general, desirable properties that magnesium hydroxide slurries should possess include:
The solids content of a magnesium hydroxide slurry is ultimately limited by its viscosity, which in turn is influenced by the particle size, shape, porosity, the number of particles, and the strength and nature of the particle-particle interactions and the particle-carrier interactions (in the present case, the carrier being water). In general, the greater the number of particles (and therefore interactions) and the greater the attractive nature of the interactions, the higher the viscosity and the lower the solids content achievable.
The reactivity is influenced by the surface area and particle size, with smaller particle sizes and higher surface areas favouring higher reactivity.
Stability to settling is mainly a function of particle size, with smaller particles giving greater suspension stability in the absence of viscosity modifiers.
Stability to ageing (i.e. no significant change in physical properties especially viscosity) appears to be related to the degree of hydration of the magnesia. It is known that substantially full hydration (i.e. greater than 98%) of MgO is difficult to achieve simply by suspending MgO in water. When MgO is hydrated in aqueous suspension, Mg(OH).sub.2 crystals tend to form on the surface of the MgO particles, thereby restricting access of water to the unhydrated MgO surface. As a consequence, the rate of hydration becomes progressively slower and a non-homogenous product can result. The properties of the product can vary with time, as the degree of hydration slowly increases. When the magnesium hydroxide is precipitated from sea-water, the product is, naturally, completely hydrated.
The aforementioned prior art refers to the use of additives including an alkali metal cation. It has now been established in experimental work referred to hereinafter that such additives, in particular sodium hydroxide, sodium acetate, sodium carbonate, sodium silicate and sodium chloride result in immediate thickening of untreated slurries or have no effect on the slurry and thus such additives are unsuitable for use as viscosity modifying agents.
It has also been established that the use of polymeric viscosity modifying agents, such as polyacrylates, have undesirable side effects in use. One side effect is that addition of a polyacrylate has the effect of first thickening the slurry to a paste and subsequently thinning the slurry following further addition of polyacrylate. The formation of a paste may cause a problem in an industrial slurry production process. Once a paste has been formed, it would be difficult to mix in further quantities of polyacrylate to fluidise the paste. Another side effect is that following addition of polyacrylate, the slurries were less reactive than the untreated slurries without polyacrylate. Another side effect is the propensity of some polymers to precipitate at low pH.


The present invention provides apparatus and a methods for collecting, transmitting and storing fugitive gas emission data. An embodiment of the invention collects fugitive gas with a sampling probe and into a emission monitoring device. The device then sends and stores fugitive gas data into a storage medium, such as a wireless data-logging adapter. The wireless-data logging adapter stores the data and wirelessly sends it to a personal digital assistant or other form of redundant memory such as a data logger. In one embodiment, the PDA can initiate commands to retrieve data from the storage medium or operate the emission gas monitoring device.

Petrochemical and refinery facilities move volatile fluids between processes through a complex array of pipes. Pipes are joined in tandem have sealed joints to prevent fugitive emissions. Pipes not joined in tandem have sealed end caps to avoid fugitive emissions. Conditions may be such that leaks develop at the seal points. These leaks, or fugitive emissions, are toxic and explosive and represent a threat to human life and property.
In order to avoid the dire results of pipe seal failures, state and federal law mandates frequent inspections and monitoring of pipe seals. In addition, petrochemical and refinery companies must maintain measurement logs along with fugitive vapor measurement data.
Piping in petrochemical and refinery companies facilities may have hundreds, or even thousands of pipe seals. Such seals are often difficult to access and require the use of ladders to realize a measurement. Current art utilizes a emission sampling probe which detects fugitive ionization emissions. The probe is connected to an gas transport conduit which function to transport vapor samples from the probe's aperture to an emissions measuring device, carried in the operator's backpack. An electrical cable extends from the emissions measuring device to a hand held data-logging device. The electrical cable extending from the backpack to the hand held device experiences constant flexing and stress, particularly at the electrical connector, such that normal use requires frequent cable replacements. In addition, when a cable breakdown data is lost or irreparably compromised. Data loss and cable breakdowns jeopardize pecuniary, property and personal safety interests.
It is desirable to find alternative means of data cabling and a means of increasing data reliability and accuracy by introducing data storage redundancy.

Apparatus and method for storing and transporting data related to vapor emissions and measurements thereof


A system and method for generating executable units suitable for unit testing of a module for integration errors, the method comprising; recording, for a module, an interface specification that specifies pre-condition constraints on input values of methods of the module and post-condition constraints on output values of the methods of the module; creating, based upon the recorded interface specification, a driver unit for the module that complies with the pre-condition constraints specified by the interface specification; and creating, based upon the recorded interface specification, a stub unit for the module that checks compliance with the specified pre-condition constraints and that complies with the specified post-condition constraints of the interface specification.

Software testing may involve coding drivers and stubs, which represents a particular development overhead as these pieces of software code are developed for unit testing of individual modules, but are subsequently discarded during module integration. However, testing of individual modules cannot be postponed until the integration testing phase. Software bugs detected during integration may necessitate several days of development effort to be undone, thus causing considerable "re-work" and, consequently, escalated project costs, and delayed delivery.
A different approach recommended by some practitioners is to follow "bottom-up" development. That is, a module M is developed before developing the modules that invoke M. This approach does eliminate the need for stubs, but following such a scheme is often not practical in large projects. On one hand, spreading the development of different module layers (often representing distinct functionalities) across different development teams, working simultaneously, is often cost-effective. On the other, since development proceeds upwards in a bottom-up approach, even a prototype of the complete application does not exist until the last module is added. This is not a situation most development teams find satisfactory.
A further approach, and the one commonly followed in practice is to create "rudimentary" drivers and stubs that have a minimum of structure and function. For example, a driver for a module M is often just a "main" program that passes particular data to M and prints relevant results. A stub is typically a dummy sub-program that may do some minimal data manipulation (for example, some input parameter to output value mapping), print verification of entry, and return. Tools may be used to generate mapping tables and wrapper code for stubs and drivers to assist in this process.
As an example, consider a program that generates a stub based on the syntactic interface of the corresponding module. The developer completes a table/vector with input values and expected return values. The stub code, when invoked, searches through the table/vector to match input parameters to records in the table and extracts the corresponding return value. Table 1 below provides an example table that may be developed from such a program. In this example, a class "calc" has a function called "divide".
TABLE 1int divide( int numerator, int denominator) throws ExceptionCalcDivideNumeratordouble{20}20Denominatordouble{4}0divide_retdouble{5}ExceptionThrowabledividebyZero
Similarly, driver generation tools provide the syntactic wrapper code to test a function. The developer needs to write the code to set the state of the object and then invoke the function under test with correct parameters.
Table 2 below presents an example of a driver generated for testing the same function ("divide") described with reference to Table 1 above, in which the code written by the developer is underlined.
TABLE 2Calc c = null;void setup( ) { //user needs to set state of object - this function //is automatically invoked before testDivide called c = new Calc( ); }int testDivide(int numerator, int denominator) { //user needs to fill in code to invoke function - e.g. int i = 10; int j = 2; System.out.println(c.divide(i,j)); }
The approaches briefly described above reduce the development overhead associated with producing stubs and drivers, but the resulting unit testing often remains far from comprehensive.
There is thus a need for an improved method of unit testing of software modules that seeks to bridge the gulf between unit and integration testing.

International Business Machines Corporation


A method is presented for operating a filesystem. The method includes (a) storing data of the filesystem in a data storage filesystem (DSFS) in block-addressable non-volatile storage and (b) storing metadata of the filesystem in a metadata filesystem (MDFS) separate from the DSFS, at least a portion of the metadata being stored in word-addressable memory (WAM) having a persistence feature. Several embodiments are described for achieving this, using, for example, only non-volatile WAM, while other embodiments are described using, for example, a combination of volatile WAM and persistence techniques, while yet other embodiments are described using, for example, a combination of persistence-enhanced WAM and data storage.

In a data storage system, data is typically stored in the context of a filesystem. In a filesystem structure, in addition to the data there is metadata which includes organizational information about the filesystem, such as directory structure, file creation and modification information, and the locations where blocks of files are actually stored. In a conventional data storage system, a unitary filesystem is utilized, in which both the data and metadata are stored on a disk or some other block-addressable persistent storage such as flash memory arranged as a solid state disk (SSD).
In some conventional data storage systems, the metadata is stored separately from the data on a separate medium. For example, since the metadata is much smaller than the data and it is accessed more frequently, a faster disk technology may be used to store the metadata. Along these lines, suppose that the data is stored on relatively cheap slowly-rotating magnetic rotating disks. In such a case, the metadata may be stored on a faster disk or on an SSD.

Techniques for storing metadata of a filesystem in persistent memory


An image forming apparatus includes a sheet feeding device that feeds a sheet, and a conveyance belt that conveys the sheet toward a printing region while attracting the sheet with electrostatic force. The printing region is disposed in a vicinity of the conveyance belt. A printing device is provided in the printing region to form an image on the sheet. A controller is provided to control the conveyance belt to stop conveying the sheet toward the printing region for a prescribed period after the tip of the sheet arrives at the conveyance belt and raised from the conveyance belt unit the tip of the sheet settles to the surface of the conveyance belt.

The present disclosure relates to image forming apparatuses and sheet conveyance apparatuses, and in particular, to those capable of electrostatically attracting and conveying a sheet using a conveyance belt.
An inkjet printing system is well known as employed in an image forming apparatus, such as a printer, a facsimile, a copier, a multiple function machine, to form an image by printing, duplicating, and imaging while adhering liquid drop to a sheet.
Specifically, a printer head having a liquid ejecting head in an inkjet printing system ejects a liquid drop during conveyance of the sheet made of various materials.
When an image is formed by such an ink jet printing system, a sheet sometimes expands and creates cockling due to moisture of the ink adhered to the sheet. The cockling causes waves in the sheet, and accordingly a positional relation between the printer head (i.e., a nozzle) and the surface of the sheet varies depending on a portion of the sheet. When the cockling reaches a worst case, the sheet can contact and stain the nozzle, and the head also stains the sheet, and therefore quality of the image deteriorates. Further, due to the cockling, a spotting position of the ink drop is displaced.
In order to maintain a sheet with an excellent flat surface, a seamless discharge belt is provided in an ink jet printing apparatus as discussed in Japanese Patent Application Laid Open No 2004-175494. Specifically, a charge belt electrostatically attracts a sheet, rotates the sheet, and conveys the sheet while preventing displacement of the sheet from the discharge belt.
Japanese Patent Application Publication No 2000-246981 discloses a copy apparatus that executes imaging on an imaging sheet while electrostatically attracting the imaging sheet by means of an electrostatic member at an imaging position to avoid occurrence of cockling and curling of the imaging sheet. The sheet conveying apparatus includes a switching device that switches from a mode in which an imaging sheet is attracted by the electrostatic attraction member to a mode in which an imaging sheet is not attracted by the electrostatic attraction member, vice versa, in accordance with a type of an imaging sheet.
However, an improved technique for avoiding cockling and curling of the imaging sheet is needed.

Sheet tip contacting belt conveying apparatus and image forming apparatus


A zoom lens system is provided that includes a compactly constructed focusing lens unit and that has a suppressed change in the image magnification at the time of movement of a focusing lens unit. The zoom lens system according to the present invention, in order from an object side to an image side, comprises: a first lens unit having positive optical power; a second lens unit having negative optical power; and at least two subsequent lens units, wherein at the time of zooming, all lens units move in a direction along the optical axis so that intervals between the lens units vary, and at the time of focusing, a second most image-side lens unit moves in a direction along the optical axis.

1. Field of the Invention
The present invention relates to a zoom lens system and, in particular, to a zoom lens system suitable for an imaging lens system employed in an interchangeable lens apparatus in a so-called interchangeable-lens type digital camera system (simply referred to as a "camera system", in some cases hereinafter). Further, the present invention relates to an interchangeable lens apparatus and a camera system that employ this zoom lens system.
2. Description of the Background Art
The market is rapidly growing for interchangeable-lens type digital camera systems each including: a camera body employing an image sensor composed of a CCD (Charge Coupled Device), a CMOS (Complementary Metal-Oxide Semiconductor) or the like; and an interchangeable lens apparatus employing an imaging lens system for forming an optical image on the light acceptance surface of the image sensor, wherein the imaging lens system is attachable to and detachable from the camera body. As for the interchangeable lens apparatuses, those employing a zoom lens system capable of forming an optical image with variable magnification are widely favored.
Among zoom lens systems, in particular, telephoto-oriented zoom lens systems have a long focal length at a telephoto limit, and hence often have a long overall optical length (a distance from the top of the lens surface on the most object side to the image surface). Thus, a configuration is often employed wherein a lens unit having positive optical power is arranged on the most object side and a lens unit having negative optical power is arranged on the most image side so that the overall optical length at a telephoto limit is made shorter than the focal length at a telephoto limit.
In telephoto-oriented zoom lens systems, configurations have been proposed wherein the number of lens units is increased for the purpose of reducing various kinds of aberration. For example, a zoom lens system consisting of five lens units of positive, negative, negative, positive and negative has been proposed (e.g., Japanese Patent Publication No. 3134448 (Reference 1)). Further, in telephoto-oriented zoom lens systems, the long focal length at a telephoto limit easily enhances image blur in association with vibration. Thus, methods have been proposed that a part of lens units (an image blur compensation lens unit) is parallel-displaced in a direction perpendicular to the optical axis in accordance with a change in the orientation of the entire lens system (e.g., Japanese Laid-Open Patent Publication No. H6-123836 (Reference 2), Japanese Patent Publication No. 3395169 (Reference 3), Japanese Laid-Open Patent Publication No. H6-130330 (Reference 4) and Japanese Laid-Open Patent Publication No. H11-202201 (Reference 5)).
Each of the telephoto zoom lens systems described in References 2, 3, and 4 consists of five lens units of positive, negative, negative, positive and negative in order from the object side to the image side. The telephoto zoom lens system described in Reference 5 consists of five lens units of positive, negative, negative, positive and negative or alternatively positive, negative, positive, positive and negative in order from the object side to the image side. In each telephoto zoom lens system, one of the five lens units is parallel-displaced in a direction perpendicular to the optical axis so that image blur compensation is achieved. When the individual lens units are referred to as the first lens unit, the second lens unit, . . . , and the fifth lens unit in order from the object side to the image side, the third lens unit in the telephoto zoom lens system described in Reference 2 is parallel-displaced in a direction perpendicular to the optical axis. Similarly, the second lens unit in the telephoto zoom lens system described in Reference 3, the fourth lens unit of the telephoto zoom lens system described in Reference 4, and a part of the second lens unit of the telephoto zoom lens system described in Reference 5 are parallel-displaced in a direction perpendicular to the optical axis.
In focusing in a telephoto zoom lens, a method of moving the first lens unit located on the most object side has widely been employed. Nevertheless, this focusing method based on the movement of the first lens unit causes a problem in that high-speed auto-focusing cannot be achieved because of the largeness and heaviness of the first lens unit. For the purpose of resolving this problem, in the telephoto zoom lens system described in Reference 5, focusing from an infinite distance to a close distance is proposed to be achieved by moving the fourth lens unit in an optical axis direction.
In interchangeable-lens type digital camera systems, video image taking is also desired in addition to still image taking. However, in video image taking, auto-focusing needs to be performed continuously at a high speed.
In order that auto-focusing should be performed continuously at a high speed, for example, a method of repeating a series of the following operations: oscillating (wobbling) a part of lens units in the optical axis directions at a high speed so that a situation of "out-of-focus state->in-focus state->out-of-focus state" is obtained; detecting, from the output signal of the image sensor, signal components in a predetermined frequency band in a part of the image region so that an optimal position realizing the in-focus state is calculated for the focusing lens unit; and moving the focusing lens unit to the optimal position, may be adopted. In order that uneasiness such as flickers should be avoided, video displaying need be performed at a high rate of, for example, 30 frames per second. Thus, basically, image taking also need be performed at the same rate of 30 frames per second. Accordingly, in auto-focusing in video image taking, the focusing lens unit need be wobbled continuously at the high rate of 30 Hz.
When the above-mentioned wobbling is to be employed, it should be noted that the size of the image corresponding to a photographic object varies in association with wobbling. This variation is caused mainly by the fact that the movement of the focusing lens unit in the optical axis directions generates a change in the focal length of the entire lens system. Then, when a large change in the image taking magnification is generated in association with wobbling, uneasiness is caused.
When the above-mentioned facts are taken into consideration, in order that the outer diameter of the lens barrel should be reduced, the weight of the image blur compensation lens unit and the focusing lens unit need be reduced as light as possible. For this purpose, the outer diameters of the individual lens elements that constitute the image blur compensation lens unit and the focusing lens unit need be reduced as small as possible so that the weight of the individual lens units need be reduced as light as possible. In this view, the techniques in the above-mentioned references have problems individually.
For example, References 1 to 4 do not mention image blur compensation. Further, in the zoom lens system described in Reference 5, the fourth lens unit that moves at the time of focusing is also composed of three or four lens elements. Thus, the fourth lens unit is heavy. This causes a problem that a larger motor or actuator for moving the fourth lens unit is required.

Zoom lens system, interchangeable lens apparatus and camera system


A computer-implemented method for selecting a desired Roman or non-Roman-alphabet character or objects from a set of non-Roman characters or objects may include steps of providing an association database that includes, for each non-Roman-alphabet character of the set, a Roman alphabet or other phonetic transliteration associated with each said non-Roman-alphabet character and a plurality of entries that are associated with each said non-Roman-alphabet character; receiving a phonetic transliteration of the desired non-Roman-alphabet character or data object and at least one associated entry that is associated with the desired non-Roman-alphabet character or other similar symbolic input; accessing the association database and identifying as candidate characters those characters of the set that are associated with the received phonetic transliteration and with the at least one received associated entry; if a number of candidate characters is greater than one, receiving additional associated entries and repeating the accessing and identifying step until a number of candidate characters is narrowed down to a single candidate character, and providing the single candidate character as the desired non-Roman-alphabet character. Also, derived from the principles described above, this invention includes a variety of methods for improving the efficiency of search engines through use of associations and other means of providing context for the item(s) being searched.

1. Field of the Invention
The present invention pertains to computer-implemented methods and systems for entering Chinese and Japanese characters for documents and for Web and other data object, image, and symbolic object or concept searching.
2. Description of the Related Art
The basic problem associated with entering Japanese and Chinese character into a computer is simply that keyboards cannot be made sufficiently large so as to accommodate the several thousand characters one would find in a Japanese newspaper, let alone the approximately 40,000 characters needed for formal Chinese technical or governmental documents. The same issues also arise in other languages. In addition, the growth in the number of character-based (Chinese, Japanese, and some Korean) websites makes it extremely difficult to search them without adequate methods of entering such characters. Furthermore, even obtaining a character and searching for it does not mean that the specific instance of the character for which the search is being performed has been isolated. Other languages, such as Arabic or Hebrew, have characters or syntax and writing styles poorly adapted to manual entry by current methods. Suboptimal solutions exist, but none function well. Conventional search systems may return desired results, but they invariably return many times as many undesired results as they do desired results.
The Japanese favor speech entry, but problems, related to speech defects or impediments, accents, pronunciations, errors (one word or character substituted for another), dialects, second or subsequent language, remain. Most current speech recognition systems require a lengthy training period to enable the machine to accurately transcribe the user's speech. Moreover, it is often necessary to train the user to exercise proper diction to enable the machine to operate at an acceptable recognition level.
Turning first to the written form of the Japanese language, the oldest common method involves the user entering a keyboarded (Romaji, or phonetic transliteration of the Japanese characters using the Roman alphabet, or kana—the Japanese phonetic characters) phonetic representation of the desired character (or phrase, meaning a cluster of characters). All similarly pronounced characters will be shown on the screen and the user is then asked to pick from among the similarly pronounced characters presented on the display. This process is slow, tedious, and does not always yield the desired characters.
Recent solutions require the user to dictate spoken Japanese or Chinese, with a software/machine translation of the spoken word into characters. The user then must edit the result or repeat the speech or confirm the result. Current methods using speech, however, are believed to lack adequate speed, precision, and suitability for all potential users. Likewise, conventional methods that rely solely on keyboard methods to enter Romaji pronunciations are believed to be slow, cumbersome and counter-intuitive. Finally, these conventional methods often interrupt the user's train of thought by requiring selection of one among many candidate characters or by requiring the user to repeat his or her speech. Often, the user may not recognize the candidate characters and is, therefore, unable to select the proper character from among the candidate characters. Moreover, these methods often fail to enable the user to reliably select the desired characters in a timely manner.
These shortcomings also manifest themselves when attempting to enter non-Roman-alphabet characters into a Web search engine for the purpose of searching Web sites containing such characters. What are also needed, therefore, are methods and systems that enable users to easily enter non-Roman-alphabet characters into a search engine and to search on the entered characters.

Computer-implemented methods and systems for entering and searching for non-Roman-alphabet characters and related search systems


A method is described for providing antisurge control in a system comprising a compressor having at least an upstream compressor stage, a downstream compressor stage and a side stream bringing flow into a flow passage between the upstream compressor stage and the downstream compressor stage. The method provides for estimating a temperature of a flow delivered by the upstream compressor stage using a non-dimensional performance map of the upstream compressor stage and further estimating a temperature of a flow entering the downstream compressor stage based on the mass flow and flow temperature of the flow delivered by the downstream compressor stage and the mass flow and the flow temperature of the side stream. The method further provides for performing antisurge control of the downstream compressor stage based on the temperature of the flow entering the downstream compressor stage.

The present disclosure relates to compressor systems and more particularly to turbo compressor systems including axial and/or centrifugal compressors for processing a gas flow. The subject matter of the present disclosure concerns methods and systems for controlling the compressor arrangement to prevent or reduce surge phenomena and other undesirable operating conditions.

Methods and systems for antisurge control of turbo compressors with side stream


A method, apparatus and computer program product are provided for ranking channel pages of a host system. Content channels may comprise content relating to a particular category or having a commonality. Explicit data provided by user input, and/or implicit data derived or received from a user device or third party may be used to generate explicit and/or implicit parameters. Based on the parameters, content channels may be ranked and displayed in an order based on the ranking, and/or a home content channel may be identified. The host system may therefore target a user with relevant content.

Various embodiments of the invention are related to a method and apparatus for ranking content channels of a host system. Through applied effort, ingenuity, and innovation, Applicant has identified a number of deficiencies and problems associated with displaying content channels. Applicant has developed a solution that is embodied by the present invention, which is described in detail below.

Method, apparatus, and computer program product for ranking content channels


A method for analyzing abnormalities in a semiconductor processing system provides performing an analysis of variance on a production history associated with each of a plurality of tools at each of a plurality of process steps for each of a plurality of processed wafers, and key process steps are identified. A regression analysis on a plurality of measurements of the plurality of wafers at each process step is performed and key measurement parameters are identified. An analysis of covariance on the key measurement parameters and key process steps, and the key process steps are ranked based on an f-ratio, therein ranking an abnormality of the key process steps. Further, the plurality of tools associated with each of the key process steps are ranked based on an orthogonal t-ratio associated with an analysis of covariance, therein ranking an abnormality each tool associated with the key process steps.

In semiconductor manufacturing, semiconductor wafers often undergo many processing steps or stages before a completed die is formed. For example, such processing steps may include lithography, etching, semiconductor doping, and deposition of various materials on the semiconductor wafer. Accuracy and precision of the processing, as well as transitions between different processing steps, often directly impacts the quality of the completed die. For example, misalignment of a gate structure, imprecise doping concentrations, or dielectric layers that are too thick or thin may cause an undesirable amount of leakage current in a transistor or delay in the operation of the circuit.
Further complicating this problem may be a semiconductor manufacturer's desire to maximize the number of dies produced by the processing steps. In an attempt to maximize productivity, a manufacturer may provide many tools for each processing step. However, each tool may have a behavior different from other tools within the particular processing step. Accordingly, determining abnormal tool and stage behavior between different tools in different steps may be difficult.
Conventional methods attempt to diagnose tool and processing stage behavior have existed in one dimension, wherein an analysis of variance (ANOVA) is used to rank suspect tools and/or processing stages. Another one-dimensional diagnosis utilizes a correlation coefficient in order to screen wafer acceptance testing (WAT) or in-line measurements. Such techniques would then be utilized to generate a scatter plot, wherein abnormal tools or stages are manually determined by eye.

2D/3D analysis for abnormal tools and stages diagnosis

Taiwan Semiconductor Manufacturing Co., Ltd.


A process for producing a liquid crystalline compound represented by the following general formula (A): ##STR1##

The present invention relates to a liquid crystalline compound and use thereof. More particularly, the present invention relates to a process for producing a novel liquid crystalline compound, which exhibits liquid crystallinity and, in addition, photoconductivity and fluorescence, and use of the liquid crystalline compound in a liquid crystalline charge transport material.
Liquid crystalline compounds having various structures are known in the art and have been extensively used as a liquid crystal display material.
Materials, wherein a charge transport molecule which serves as a charge transport site are dissolved or dispersed in a matrix material, such as a polycarbonate resin, or materials, wherein a charge transport molecule structure pends as a pendant on a polymer backbone, such as polyvinyl carbazole, are known in the art. These materials have been extensively used as materials for photoconductors in copying machines, printers and the like.
For the above conventional charge transport materials, in the case of dispersive charge transport materials, that the charge transport molecule has high solubility in the polymer as a matrix is preferred from the viewpoint of improving the charge transport capability. In fact, however, bringing the charge transport molecule to a high concentration in the matrix leads to crystallization of the charge transport molecule in the matrix, and, for this reason, the upper limit of the concentration of the charge transport molecule is generally 20 to 50% by weight although it varies depending upon the kind of the charge transport molecule. This means that the matrix not having charge transport capability occupies not less than 50% by weight of the whole material. This in turn raises a new problem that the charge transport capability and response speed of a film formed from the material are limited by the excess matrix present in the material.
On the other hand, in the case of the pendant type charge transport polymer, the proportion of the pendant having charge transport capability can be increased. This polymer, however, involves many practical problems associated with mechanical strength, environmental stability and durability of the formed film, film-forming properties and the like. In this type of charge transport material, the charge transport pendants are locally located in close proximity, and the local proximity portion serves as a stable site in hopping of charges and functions as a kind of trap, unfavorably resulting in lowered charge mobility.
For all the above charge transport materials, electrical properties of such amorphous materials raise a problem that, unlike crystalline materials, the hopping site fluctuates in terms of space, as well as in terms of energy. For this reason, the charge transport depends greatly upon the concentration of the charge transport site, and the mobility is generally about 10.sup.-6 to 10.sup.-5 cm.sup.2 /vs which is much smaller than that of the molecular crystal, 0.1 to 1 cm.sup.2 /vs. Further, the amorphous materials have an additional problem that the charge transport properties depend greatly upon temperature and field strength. This is greatly different from the crystalline charge transport materials.
A polycrystalline charge transport material is a promissing material in applications where a charge transport layer having a large area is necessary, because it can form an even charge transport film having a large area can be evenly formed. The polycrystalline material, however, is inherently an uneven material from the microscopic viewpoint and involves a problem that a defect formed in the interface of particles should be inhibited.
Accordingly, the present invention aims to solve the above problems of the prior art and to provide a novel charge transport material which simultaneously realizes advantages of the amorphous materials, that is, structural flexibility and evenness in a large area, and advantages of the crystalline materials having molecular orientation and is excellent in high-quality charge transport capability, thin film-forming properties, various types of durability and the like.

Liquid crystalline compound and use thereof


The process for the realization of a window/door framework (1) for walls of building comprises a molding step of a perimeter frame (2) by means of a three-dimensional molding device (5, 6, 7, 9), wherein the perimeter frame (2) comprises a plurality of perimeter sides made in a single monolithic body.

The present invention relates to a process for the realization of a window/door framework for walls of buildings.
Within the ambit of the present discussion by window/door framework is meant a structure intended to close an opening (window, door, flap etc.) made in an outer or inner wall, in the floor or in the roof of a building.
The structure can be either movable (e.g. the leaf of a window) or fixed (e.g. permanently secured to the wall).
The window/door frameworks usually consist in an outer frame, made of materials such as aluminum, plastic or the like, and in an inner panel, made of glass, Plexiglas or other material (either transparent or non-transparent).
With specific reference to the field of window/door frameworks with frames made of plastic, it is emphasized that the processes for the realization of these frames generally comprise the sealing of a plurality of corresponding profiled elements together, preferably made of PVC or other heat-sealable plastic materials.
The profiled elements have a particular multi-chamber structure inside the profiled elements themselves which allows ensuring a high degree of thermal insulation.
The plastic profiled elements so made have the main drawback related to the low resistance due to stresses and movements applied by externally exerted forces.
With reference to this drawback, prolonged exposure to sunlight causes, for example, heating of the plastic profiled elements due to the transmission of heat by irradiation with a consequent increase in the risk of deformations of the profiled elements themselves.
To obviate this drawback it is known to use reinforcing elements introduced in the containment seats defined in the profiled elements, and which extend along the entire extension of the profiled elements themselves, in order to give greater stability and reinforcement to the structure of the profiled elements themselves. Generally, such reinforcing elements are of the type of metal bars that are hardly deformable by applied stresses and which are inserted in the containment seat.
To insert the metal bars inside the containment seat of each profiled element, they must have a cross section with smaller overall dimensions than the cross section of the containment seats themselves.
Such metal bars can be movable inside the containment seats and need to be blocked to the structure of the profiled elements by means of suitable fixing machinery.
It also follows that these profiled elements have an increase in thermal conductivity and a related reduction in thermal insulation that the window/door framework made of plastic material provides between the interiors and the external environment.
After the assembly step of the metal bars inside the containment seats, the sealing operation of the profiled elements takes place through the melting of the respective head surfaces obtained by heating the portions to be connected by means of suitable electric resistance plates, and then pressing the heated portions one against the other until their mutual union.
Generally, the heated portions are the head extremities of the profiled elements, suitably cut at 45° to define, e.g., a right-angled portion of the frame.
At the line of union of the head surfaces of the profiled elements (surfaces cut at) 45°, the exceeding portion of molten material comes out and forms a bead protruding from the surface in view of the profiled elements.
For this reason, in order to give the finished window/door framework an appreciable aesthetic appearance, once sealed, the profiled elements undergo a sealing bead removal machining operation.
Generally, prior to the profiled element sealing step, the fixing of seal elements takes place, e.g. of the type of rubber sheaths, to the surfaces of the profiled elements that, in an assembly configuration, are facing to the glass inner panel. These known types of processes for the realization of window/door frameworks do have some drawbacks.
The main drawback is linked to the assembly operations of the profiled elements by sealing the head surfaces of the profiled elements to each other and the fixing of the reinforcing metal bars inside the respective containment seats which are particularly difficult and impractical for the assigned operator.
It follows that the assembly operations require long execution times and particularly complex and bulky machines with consequent reductions in the output production and high retail prices.
Another drawback is linked to the fact that the extrusion operations of the plastic profiled elements for obtaining the desired special multi-chamber structure are complex and require long production times.
Another drawback is related to the assembly operations of the seal elements to the surfaces of the profiled elements facing to the glass panel portions that are scarcely practical and safe since, during the glass inner panel assembly operations, such seal elements may be accidentally damaged or removed.
Another drawback relates to the fact that PVC window/door frameworks made using traditional processes are not particularly attractive from the aesthetic point of view.
Sometimes, therefore the window/door frameworks are made with a surface finish reproducing a material effect, in particular the wood effect, so that they are more pleasing to the sight.
The decoration of the window/door frameworks for obtaining the material effect can be accomplished by means of various techniques, such as the pigment sublimation, which consists in molding the motif simulating the wood grains on a flat surface on a special support and then transferring it by means of a hot process onto the surface to be decorated which has been appropriately pretreated so as to be perfectly receptive.
It is a decal in which the transfer of the decoration takes place at high temperatures and with suitable depressions, through which the solid pigment turns directly into vapor and penetrates simultaneously into the pre-treated surface of the window/door frameworks.
An alternative method commonly used for obtaining the material effect is the direct powder deposition, by means of which the polyester powders of different colors in the solid state are directly incorporated in the pre-treatment layer of the window/door framework.
These are however very complex and expensive methods that do not allow for obtaining a realistic material effect.

Process for the realization of a window/door framework for walls of buildings


A device for carrying or dragging various objects, such as animals, has a triangular-shaped handle with an eye formed proximate the object for receiving a rope to be connected to the object. The load associated with the object is concentrated at the eye of the handle.

The present invention relates to devices which aid in the carrying or dragging of various objects, such as deer, elk, moose, etc., from one point to another.
In particular, hunters have been confronted with the problem of moving a slain animal, especially large animals, from a hunting ground to a place for ultimate transport or dressing. This is particularly true where hunting is conducted in isolated areas or in areas characterized by terrain which is difficult to traverse. Prior art game dragging devices are known that have various deficiencies.
For instance, the game dragging device disclosed in U.S. Pat. No. 4,243,164 (Burlison, et al.) discloses a handle which is directly connected to the appendages, such as legs and neck, of an animal to be dragged. The person moving the animal would have to be very close in proximity to the animal which would tend to make walking difficult and dragging the animal unmanageable, especially along rough terrain. Further, with the neck also supported by the handle, the animal's head would have to be raised at least above ground level to prevent the head from becoming ensnarled in bushes, vines, logs, etc. This would be especially true for animals such as deer, elk, and moose that have antlers which extend from the head. It would also be difficult for two people to jointly move a slain animal given the arrangement of the handle disclosed in the Burlison patent.
U.S. Pat. No. 4,529,240 (Engle) discloses a device for carrying and skinning animals which employs two essentially separate handle, rope, and loop combinations which are connected to an animal to be moved. One problem with this device is that the load of the animal would be applied separately and unevenly to the two lengths of rope, especially when two people pull respectively on the two handles. The handles disclosed are not rigged and if the handles were combined to overlap one another, it would be unmanageable for two individuals to jointly carry or drag a slain animal.

Device for carrying or dragging an animal


A phase change memory device includes a cell array unit including a phase change resistance cell positioned at an intersection of a word line and a bit line. A plurality of sense amplifiers sense and amplify data of the phase change resistance cell selected using a plurality of reference currents. A plurality of comparing units compare an output signal of the corresponding sense amplifier with that of the neighboring sense amplifier so as to output a flag enable signal.

The present invention relate generally to a phase change memory device and an operating method thereof, and more particularly to a phase change memory device and an operating method thereof for outputting effective cell data by applying a reference current suitable for the characteristics of each cell of the memory.
A nonvolatile memory has a data processing speed similar to that of a volatile Random Access Memory (RAM), however, unlike a volatile RAM, a nonvolatile memory conserves a data even when no power is supplied to the memory, i.e., when the power is turned off. Examples of a nonvolatile memory include a magnetic memory and a phase change memory (PCM).
FIGS. 1a and 1b are diagrams showing a conventional phase change resistor (PCR) 4.
The PCR 4 comprises a phase change material (PCM) 2 inserted between an upper electrode 1 and a lower electrode 3. When a voltage and a current are applied to the conventional PCR 4, a high temperature is generated in the PCM 2 such that an electric conductive state of the PCR 4 changes depending on the resistance of the PCM 2.
The PCM 2 may comprise AgLnSbTe. The PCM 2 may also comprise chalcogenide having chalcogen elements (S, Se, Te) as a main ingredient, and specifically includes a germanium antimonic tellurium (Ge2Sb2Te5) consisting of Ge—Sb—Te.
FIGS. 2a and 2b are diagrams showing the principle operation of the conventional PCR 4.
As shown in FIG. 2a, the PCM 2 can be crystallized when a low current, i.e., a current less than a threshold value, flows into the PCR 4. As a result, the PCM 2 is crystallized and acts as a low resistance material.
As shown in FIG. 2b, the PCM 2 can be amorphized when a high current, i.e., a current higher than a threshold value, flows into the PCR 4. That is, the temperature of the PCM 2 is increased higher than the melting point of the PCM 2 when a high current flows into the PCR 4. As a result, the PCM 2 becomes amorphous and acts as a high resistance material.
In this way, the PCR 4 is configured to store a nonvolatile data corresponding to the two resistance states. Data "1" refers to a low resistance state of the PCR 4, and data "0" refers to a high resistance state of the PCR 4, and as such the data can be stored to have one of the two logic states.
FIG. 3 is a diagram showing a write operation of a conventional phase change resistant cell.
Heat is generated when a current flows through the upper electrode 1 and the lower electrode 3 of the PCR 4 for a given time. As a result, a state of the PCM 2 is changed to be either crystalline or amorphous depending on the temperature generated according to the current applied to the upper electrode 1 and the lower electrode 3.
A low temperature heating state occurs when a low current flows for a given time. As a result, the PCM 2 becomes crystalline and the PCR 4, which acts as a low resistor, is at a set state. On the other hand, a high temperature heating state occurs when a high current flows for a given time. As a result, the PCM 2 becomes amorphous and the PCR 4, which acts as a high resistor, is at a reset state. A difference between two phases is represented by a change in electric resistance.
As shown in FIG. 3, a low voltage is applied to the PCR 4 for a period of time in order to write the set state in a write mode. On the other hand, a high voltage is applied to the PCR 4 for a shorter period of time in order to write the reset state in the write mode.
FIG. 4 is a diagram showing a read current relationship of a conventional phase change memory device.
Each cell included in a plurality of cell arrays has a different read current distribution depending on process, element, and design conditions. That is, the distribution of a set current Iset and a reset current Ireset becomes broader based on a single reference current Iref.
If a characteristic group of each cell is divided into three regions A, B, C, the distribution of the set current Iset and the reset current Ireset is located at a different region. As a result, read currents are overlapped in some cells based on the single reference current Iref.
A fail condition may occur in some cells when the reset current Ireset is incorrectly distinguished from the set current Iset by the reference current Iref due to the overlap discussed above.

Phase change memory device having a plurality of reference currents and operating method thereof