Provided are a method, system, and program for communicating with a device. A kernel module is executed in memory and at least one kernel thread is executed in the memory to handle calls to device driver functions for the kernel module. The at least one kernel thread executes calls to device driver functions for the kernel module running in a kernel context.

1. Field of the Invention
The present invention relates to a method, system, and program for accessing device driver functions.
2. Description of the Related Art
A device driver is a program that includes device specific commands to communicate with and control attached devices. The device driver provides an interface between an operating system, such as Microsoft Windows®, Linux®, Unix®, etc., and a device, such as a network adaptor card, printer, video controller, etc., to enable the operating system and application programs executing therein to transmit commands to access information and control the device. In the Linux operating system, a user application program calls a device driver application program interface (API) via special IOCTL system calls to perform device related operations, such as getting network device statistics and setting device parameters such: as the Media Access Control (MAC) address for the device packet filtering, the maximum transmission unit (MTU)—which is the largest physical packet size transmitted on the network, etc.
The operating system runs a kernel, which is a central module of the operating system that is typically loaded first and remains in memory. The kernel is responsible for managing the execution of tasks and resource allocation, such as memory and processing resources. Tasks assigned by the kernel may execute in kernel mode or user mode. In kernel mode, tasks such as scheduling the running processes, interrupt handling, direct memory access, etc., are performed. In this mode, rescheduling (such as sleep operations) is not always allowed. User mode is for operations, such as running user applications and executing system service calls for applications. In this mode, rescheduling is allowed. Normally device driver APIs, such as the IOCTL commands, are initiated by system calls and therefore executed in user mode. Hence, device drivers are usually coded to process those APIs in a manner where processing may be rescheduled.
A kernel module, either statically linked or dynamically loaded, runs within the kernel and manages execution of code that must run at high priority and that needs privileged access to kernel resources. A device driver for example is a kernel module. An intermediate driver that is layered between the operating system and device drivers, and implements device teaming and other advanced features is also a kernel module.
A kernel module such as an intermediate driver usually operates in a high context (kernel mode), such as soft IRQ context (which includes timers, receive and transmit flows of an intermediate driver—formally known as bottom halves) or hard IRQ context. In certain situations, a kernel module may need to call the device driver's API directly. However, as discussed above, because the device driver's API is coded to run in user mode, this could cause a system crash.

Method, system, and program for accessing device driver functions


The present invention relates to a non-aqueous electrolyte solution which includes an ionizable lithium salt, an organic solvent, and a mixed additive, wherein the organic solvent comprises at least one cyclic carbonate-based organic solvent selected from the group consisting of ethylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate, vinylene carbonate, and fluoroethylene carbonate, and at least one linear carbonate-based organic solvent selected from the group consisting of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethylmethyl carbonate, methylpropyl carbonate, and ethylpropyl carbonate, the mixed additive includes vinylene carbonate, 1,3-propylene sulfate, and 1,3-propane sultone in a weight ratio of 1:1:1 to 1:0.5:0.2, and a total amount of the mixed additive is in a range of 1 to 4.5 wt % based on a total weight of the non-aqueous electrolyte solution for a lithium secondary battery, and a lithium secondary battery including the same.

Recently, interests in energy storage technologies have been increasingly grown, and efforts for the development of high-capacity electrochemical devices have been gradually materialized as the application of the energy storage technologies is expanded to mobile phones, camcorders, notebook PCs, and even to electric vehicles.
There emerges an interest in rechargeable secondary batteries among these electrochemical devices, and, particularly, lithium secondary batteries developed in the early 1990's are spotlighted because the lithium secondary batteries are advantageous in that they have higher operating voltage and significantly higher energy density.
A lithium secondary battery is composed of a negative electrode, such as a carbon material capable of intercalating and deintercalating lithium ions, a positive electrode formed of a lithium-containing composite oxide, and a non-aqueous electrolyte solution in which a lithium salt is dissolved in a mixed organic solvent.
In the lithium secondary battery, lithium ions react with the electrolyte solution in a voltage range of 0.5 V to 3.5 V during initial charge to form compounds, such as Li2CO3, Li2O, and LiOH, and a solid electrolyte interface (SEI) film, as a kind of a passivation layer, is formed on the surface of the negative electrode by these compounds.
The SEI film formed at an initial stage of charging may prevent a reaction of the lithium ions with the carbon negative electrode or other materials during charge and discharge. Also, the SEI film may only pass the lithium ions by acting as an ion tunnel. Since the ion tunnel may prevent the destruction of a structure of the carbon negative electrode due to the co-intercalation of the carbon negative electrode and the non-aqueous organic solvents having a high molecular weight which solvate lithium ions and moves therewith, cycle life characteristics and output characteristics of the lithium secondary battery may be improved.
In a case in which the organic solvent used in the non-aqueous electrolyte solution of the lithium secondary battery is generally stored for a long period of time at high temperature, gas is generated due to the occurrence of a side reaction of the organic solvent with a transition metal oxide of a discharged positive electrode active material. Furthermore, the negative electrode is exposed while the SEI film is gradually collapsed during high-temperature storage in a fully charged state (e.g., storage at 60° C. after charged to 100% at 4.2 V), and the exposed negative electrode continuously reacts with the electrolyte solution to generate gases, such as CO, CO2, CH4, and C2H6.
Battery swelling and deformation of an electrode assembly occur while an internal pressure of the battery is increased by the gas thus generated, and, as a result, the battery may be deteriorated due to internal short circuit of the battery, or fire or explosion of the battery may occur.
In order to address these limitations, there is a need to develop an electrolyte solution for a lithium secondary battery which may suppress the side reaction during high-temperature storage.

Non-aqueous electrolyte solution for lithium secondary battery and lithium secondary battery including the same


A method of producing a cleaning blade comprising steps of filling the cavity of a mold with a liquid composition containing prepolymer for forming urethane rubber, a curing agent and quaternary ammonium salt represented as the following general formula (1) as a catalyst, curing the composition, and unmolding the cured matter and a composition employed therein. ##STR1## wherein R.sub.1,2,3 means --C.sub.n H.sub.2n+1 wherein n represents 0 or a positive integer, R.sub.4 means --C.sub.n H.sub.2n wherein n represents a positive integer and R.sub.5 means --C.sub.n H.sub.2n+1, wherein n represents 0 or a positive integer, or --CH.sub.2 --CN.. For this reason, it does not take a long time for curing a liquid composition, unlike the prior methods, resulting in improvement in product efficiency. Furthermore, since the pot life of the liquid composition is long, fluidity is good and no defective products may not be caused.

It is a general method of photocopying with an electrophotographic printer that a peripheral surface of a photosensitive drum is uniformly charged, the peripheral surface is exposed by the copied image of a subject so as to form an electrostatic latent image on the peripheral surface, toner is attached to the electrostatic latent image so as to form a toner image, and the toner image is copied on a sheet of paper and the like.
In such an electrophotographic printer, toner remains on the peripheral surface of a photosensitive drum after the toner image is copied and is generally removed by scraping with a cleaning blade 1 having a holding plate 2 as shown in FIG. 1.
As an elastic body employed for the cleaning blade 1, urethane rubber is prevalently used for its superior dynamical properties such as abrasion resistance. The cleaning blade 1 made of urethane rubber is produced, for example, by a prepolymer method comprising steps of providing a mold having a cavity for forming the cleaning blade, filling the cavity of the mold with a liquid composition containing prepolymer wherein polyisocyanate and polyol are partially polymerized (hereinafter referred to `urethane-rubber-forming prepolymer`), a curing agent and a catalyst, curing the composition and unmolding thus obtained cured matter.
However, it takes time in the above method to fill the cavity of the mold with a liquid composition and cure thereof, resulting in bad product efficiency. Even if the amount of a catalyst in the liquid composition is increased for shortening an unmolding time with intention to improve product efficiency, the liquid composition cannot spread uniformly through the mold because a curing reaction of the liquid composition rapidly progresses so that the viscosity thereof increases as the catalyst increases in amount, resulting in increase in the number of defects due to insufficient fluidity in case that triethylenediamine (TEDA), dimethylimidazole (DMIZ) or the like, prevalently used heretofore, is adopted as a catalyst. Further, since the liquid composition containing urethane residue cured in a mixing chamber of a casting machine is cast into the mold, cleaning properties of thus obtained product may be deteriorated. For this reason, it is a current situation that product efficiency can not be improved by increasing the amount of the catalyst. In addition, there is another problem that a large-sized molding can not be obtained because of low fluidity.

Method of producing cleaning blade and composition employed therein


Disclosed herein is an optical add/drop device including an optical demultiplexer for separating WDM signal light into n optical signals where n is an integer not less than 2, n first optical switches to which the n optical signals output from the optical demultiplexer are supplied, respectively, a second optical switch for adding provided on the input side of the first optical switches, a third optical switch for dropping provided on the output side of the first optical switches, n regenerators for wavelength converting the optical signals passed through the first optical switches, and an optical multiplexer for wavelength division multiplexing the wavelength-converted optical signals. A transmission distance between nodes can be increased by using this device.

1. Field of the Invention
The present invention relates to an optical add/drop device.
2. Description of the Related Art
With a recent increase in traffic, a large-capacity network has been required. To meet this requirement, the construction of a WDM (wavelength division multiplexing)-based optical network will be necessary in a future trunk network. An optical add/drop device (optical ADM: optical add/drop multiplexer) capable of adding and/or dropping optical signals having different wavelengths by the wavelength between this device and another network device such as a router and an ATM (asynchronous transfer mode) switch is used in an optical network. It is important to form a ring network by using this optical ADM and to form an optical network tolerant of failure.
FIG. 1 is a block diagram of a general optical add/drop device in the prior art. An optical add/drop device 2 is arranged along an optical transmission line 4 for transmitting WDM signal light obtained by wavelength division multiplexing a plurality of optical signals having different wavelengths λ1 to λn (n is an integer satisfying 1<n). This device 2 has an optical demultiplexer 6 for separating the WDM signal light supplied from the input-side optical transmission line 4 into the optical signals having the wavelengths λ1 to λn, n 2×2 optical switches 8 for selecting optical signals to be passed through this device 2 and optical signals to be added/dropped, and an optical multiplexer 10 for wavelength division multiplexing optical signals to be output to the output-side optical transmission line 4.
k (k is an integer satisfying 1<k) regenerators 14 each having a wavelength conversion function are provided for an interface between this device 2 and another network device for an add signal, such as a router 12, and k regenerators 18 each having a wavelength conversion function are provided for an interface between this device 2 and another network device for a drop signal, such as an ATM switch 16.
Examples of each optical switch include a waveguide switch using a thermooptic effect and a mechanical switch having a motor. Examples of a wavelength converter usable as each regenerator include an all-optical wavelength converter using a semiconductor optical amplifier and a wavelength converter using opto/electrical conversion and electro/optical conversion. Examples of the optical multiplexer or the optical demultiplexer include a device using an arrayed waveguide grating (AWG) and a device using a dielectric multilayer film.
A device controller 20 is provided in the optical add/drop device 2 to perform setting or the like for signal adding, dropping, or passing according to instructions from an operation system 22 for supervising and controlling the whole of an optical network. In this manner, the optical add/drop device 2 selects signal adding, dropping, or passing to thereby allow a flexible operation of the optical network.
In the device shown in FIG. 1, an optical signal from the router 12 is wavelength converted by each regenerator 14 and accommodated into the optical network at the wavelength assigned to an input port of the optical multiplexer 10. That is, wavelengths are fixedly assigned in the optical network. For more flexible and efficient operation of the optical network, it is desirable that an optical signal can be accommodated into the optical network at an arbitrary wavelength.
FIG. 2 is a block diagram of an improved optical add/drop device in the prior art. In this device, k tunable wavelength converters 28 are used in place of the k regenerators 14 shown in FIG. 1. Further, a k×n optical switch 24 is provided between the tunable wavelength converters 28 and the optical switches 8, and an n×k optical switch 26 is provided between the regenerators (wavelength converters) 18 and the optical switches 8. The optical switches 24 and 26 may be replaced by AWGs. The number k represents the number of ports of an intraoffice interface between this device and another network device such as a router 12 and an ATM switch 16, and the number n represents the number of WDM channels. Accordingly, k□n in general.
In the improved optical add/drop device mentioned above, an optical signal from the router 12 can be wavelength converted to be added to an arbitrary wavelength channel owing to the use of the tunable wavelength converters 28 and the optical switch 24. In case of converting the wavelength of an optical signal to be added into a wavelength λn, the optical switch 24 is controlled to perform routing so that the optical signal from the router 12 is passed through the optical switch 8 connected to the input port of the optical multiplexer 10 corresponding to the wavelength λn.
In the prior art, the optical signals passing through the optical add/drop device are not subjected to wavelength conversion. Accordingly, a function of waveform shaping or the like associated with signal regeneration processing cannot be obtained, so that long-haul transmission is difficult to attain.
Further, in the prior art, a tunable wavelength converter including a tunable light source is necessary at an interface between the optical add/drop device and another network device such as a router and an ATM switch, so as to add a signal from the other network device to an arbitrary wavelength channel in the optical network.
Referring to FIGS. 3A and 3B, there are shown different tunable light sources in the prior art. In the configuration shown in FIG. 3A, a plurality of laser diodes (LD1 to LDn) 30 are kept steadily driven, and CW light (DC light or unmodulated light) output from one of the laser diodes 30 selected by an n×1 optical switch 32 is modulated by an optical modulator (Mod) 34 to obtain an optical signal having a desired wavelength. An optical signal from another network device is converted into an electrical signal by an opto/electrical (O/E) converter 36, and this electrical signal is supplied as a modulating signal to the optical modulator 34. The optical switch 32 is controlled by a device controller 38.
In this configuration, the time for switching wavelengths depends on the transit time of the optical switch 32. Further, there is a possibility of crosstalk in the optical switch 32 and an increase in cost and power consumption.
In the configuration shown in FIG. 3B, a plurality of drive circuits (DRV) 42 respectively associated with a plurality of laser diodes 40 are turned on/off by a device controller 44 to select one of the laser diodes 40 and steadily drive it. CW light output from the selected laser diode 40 is modulated by an optical modulator 48 to thereby obtain an optical signal having a desired wavelength. An optical signal from another network device is converted into an electrical signal by an opto/electrical converter 50, and this electrical signal is supplied as a modulating signal to the optical modulator 48. The plural laser diodes 40 and the optical modulator 48 are optically connected by an AWG 46.
Also in this configuration, the LDs and the DRVs whose number corresponds to the number of wavelengths for each are required as similar to the previous configuration shown in FIG. 3A, causing an increase in cost.
Thus, a tunable light source is required in the prior art, so as to add a signal from another network device to an arbitrary wavelength channel in the optical network, resulting in an increase in cost of the optical add/drop device.


Amplification and synchronization of photon pulses in optical computing chips is accomplished by placing parametric amplifying devices at predetermined spatial locations in the light conductive paths that make up the optical circuits in the chip. The laser pumping signal for the parametric amplifiers is clocked by a system clock which also clocks the generation of the data photon pulses in the optical circuits. By synchronizing the arrival of a pumping pulse with the arrival of the photon pulse at a parametric amplifier, the data pulse can be amplified, reshaped and resynchronized. The pumping pulse can be directed to the spatially located parametric amplifiers on the chip in a number of different ways. The chip could be masked except for the parametric amplifiers, and the entire chip could be illuminated by the pumping laser though collimating lens. If the chip is not masked, then pumping light must be directed only to the parametric amplifiers. This could be done with a hologram to spatially distribute the light beams to the amplifiers. Alternatively, the beam from the pumping laser could be piped by light conducting fibers to the parametric amplifiers with light pipes. Further, the light pipes for the pumping pulses could be light conducting channels in a second optical chip, or an additional optical circuit layer.

1. Field of the Invention
This invention is directed to an optical computing system. More particularly, it is directed to the manipulation of photon signals as they pass through the optical computing system, and optical computing chips in that system.
2. Description of Prior Art
An important problem in the operation of an optical computing chip in a high speed optical computing system is the distribution of a clock pulse signal in space and time so that the clock can be used to synchronize various logical operations in the chip with the photon signals passing through the chip. The problem is particularly difficult, as the width of photon signal pulses shortens to a picosecond and even sub-picoseconds. Further, such a pulse at any given instant occupies only a few microns of space as it travels through the computing chip. Therefore, if two or more photon pulses are to interact, they must arrive at the correct spatial position within microns and at the correct time within sub-picoseconds.
A secondary problem in the operation of an optical computing chip is the loss of signal amplitude, or the loss of pulse signal shape (narrower or wider) as the photon pulse passes along the light conducting paths of the chip. Typically, logic devices in an optical computing chip are passive devices and do not amplify the photon signals. Further, a photon pulse that is deteriorating may be further clipped in duration, or amplitude, by the optical logic devices.
The prior art contains examples of optical logic devices, optical computing chips, and optical parametric amplifiers. U.S. Pat. No. 4,405,869, issued to George A. May et al, is a good example of an optical logic device that can be configured as "AND" or "OR" logical gate. U.S. Pat. No. 4,900,115, issued to Vincent P. Heuring et al, describes optical modules, or chips, containing multiple optical logic devices. U.S. Pat. No. 4,180,751, issued to Eugene O. Ammann, and U.S. Pat. No. 4,880,996, issued to Phillip R. Peterson et al, are examples of parametric amplifying devices. The prior art does not address the problem of system distribution of clock pulse signals in space and time in an optical computing system. Further, the prior art does not address the problem of time and spatial deterioration of photon pulse signals in optical chips in an optical computing system.

Amplifying and synchronizing signals in optical computing system

The Regents of the University of Colorado


An automated system for compensating the pan and tilt of a camera head for the movements of a camera support structure and/or a subject matter. A processing system receives signals relating to the movement of the camera support structure, such as the swing, boom and telescope of the crane arm, the movements of a dolly, and preferably the movements of a subject matter. The system employs these inputs to determine the position of the camera and subject matter in a defined world coordinate system and sends signals to compensate the pan and tilt of the camera head so that the field of view of the camera is generally centered on the subject matter being filmed as defined within the system.

Traditionally, camera cranes and dollies have been employed to assist in the positioning of cameras at defined locations and orientations to capture the desired shot. Conventional camera cranes are generally comprised of a crane arm (or "jib"), a support structure to which the crane arm is mounted, and a "leveling head" affixed to the distal end of the crane arm. Typically, the crane arm is pivotally coupled to the support structure in a manner that facilitates the rotation of the crane arm about a vertical and a horizontal axis. The rotation of the crane arm about the vertical axis is generally referred to as crane arm "swing," while the rotation of the crane arm about the horizontal axis is generally referred to as crane arm "boom." In addition to the crane arm being capable of swing and boom, conventional crane arms are often constructed to be adjustable in length, so that the crane arm can "telescope" from one length to another. Thus, the distal end of the crane arm (i.e., the end affixed to the leveling head) is capable of translating through a semi-sphere, the diameter of which is controlled by the overall length of the crane arm, which can be adjusted by telescoping the crane arm. Moreover, camera cranes are often mounted on a rolling platform that is generally referred to as a "dolly."
Conventional camera dollies are different from the dollies used to support camera cranes mentioned above, in that instead of supporting a complex crane arm that can swing, boom and telescope, conventional camera dollies support a simpler camera platform which may only be raised or lowered. Conventional camera dollies exist in two basic forms, and typically employ wheels for movement. Some dollies have rectangular-shaped frames with a steering lever at the back, and others are symmetrical and steerable from any side. The camera platform is provided on the dolly for mounting a camera, and is typically supported by a single or double hinged arm which raises or lowers the platform using a hydraulic ram. Other dollies provide vertical movement using a hydraulic center post. In either case, the platform is raised in a vertical direction with respect to the frame of the dolly, and a leveling mechanism may be employed within the arm or post to maintain the platform level with respect to the frame of the dolly.
In a modern dolly, several modes of steering may be available. In a "conventional" mode of steering, the back wheels turn and the front wheels are fixed, or vice versa. In another mode of steering, called a "crab" mode, all four wheels turn together in parallel. In a "modified crab" mode, the front wheels turn together, and the back wheels turn together, but the front and back wheels are not necessarily parallel (typically the front wheels turn more than the back wheels). In yet another mode of steering called a "roundy" mode, the wheels are oriented so that the dolly can spin in place. Some dollies are configured for only one of these modes. By moving a lever on the dolly, other dollies are configurable into one of these modes.
Dollies are typically pushed and steered, and their platforms raised and lowered, by a dolly grip. Even though the technology exists to control the dolly remotely, it is difficult to replace the human element of an experienced dolly grip, who is able to watch a scene being performed and position and move the dolly while anticipating and compensating for deviations from the planned rehearsed movements of the actors. Moreover, dolly grips generally move at the same rate as actors, unlike joysticks and computer controls, which can move abruptly, and are thus generally better than remote controls at compensating for movements of actors.
The leveling head is a mechanism that is typically employed to connect the camera crane arm to a camera mounting structure referred to as a "camera head." Leveling heads are generally comprised of a leveling mechanism that functions to maintain a "leveling plate" parallel to a defined plane in response to changes in the boom of the crane arm. As used in this application a "leveling plate" is a defined member of the leveling head that is adapted to being coupled to the camera head. An example of such a leveling head is disclosed in U.S. Pat. No. 4,943,019, which is hereby incorporated by reference.
Conventional camera heads, in addition to providing a support structure to securely mount the camera, are typically adapted to rotate about a vertical axis (i.e., panning) and a horizontal axis (i.e., tilting) relative to the leveling plate. To facilitate the panning and tilting of the camera head, two independently actuated motor mechanisms are usually employed. The first is often referred to as a "camera pan motor," which as the name suggests facilitates the panning of the camera head (i.e., the rotation of the camera head about the vertical axis). The second is often referred to as a "camera tilt motor," which also as the name suggests facilitates the tilting of the camera head (i.e., the rotation of the camera head about the horizontal axis).
In operation, the boom (i.e., the rotation of the crane arm about a horizontal axis), swing (i.e., the rotation of the crane arm about a vertical axis), telescope (i.e., the length of the crane arm), and the movement of the rolling platform or dolly are typically controlled manually by one or more operators or "grips." The adjustments of the leveling head are usually automated to respond to the change in the boom so as to maintain the camera head generally level to the horizontal plane. The "pan" and "tilt" of the camera head together with the focus of the camera, on the other hand, have been traditionally controlled remotely (usually via electrical circuitry) by another operator, referred to as the "camera-operator," who is responsible for the composition of the shot (i.e., the field of view and focus of the camera).
Thus, the camera-operator, in fashioning the composition of the shot, must compensate the field of view of the camera by panning and tilting the camera head in response to movements of the crane arm, dolly, and the subject matter being filmed. In light of the complex dynamics of such systems, the camera-operator's task can be extremely difficult, especially when filming complicated shots. Consequently, situations inevitably arise where the field of view of the camera is not accurately or in a timely fashion compensated for the movements of the crane arm and/or dolly. In addition, situations also arise, with or without movement in the camera crane or dolly, where the field of view of the camera is not accurately compensated for the movement of the subject matter. As a result, considerable expense and time is expended in re-shooting.
To assist the camera operator in achieving the desired composition, some camera heads such as those disclosed in U.S. Pat. Nos. 5,644,377 and 5,835,193, which are hereby incorporated by reference, employ an automated back pan compensation mechanism that, when activated, pans the camera head in a reverse direction relative to the swing of the camera crane arm. The amount of pan compensation may be adjusted by the user prior or during filming. These compensation mechanisms, however, simply reverse pan the camera head in response to changes in the swing of the crane arm without reference to the other potential movements of the camera support structure (e.g., boom, telescope, or dolly movement) or changes in the position of the subject matter being filmed. Furthermore, these compensation mechanisms are not readily suited for achieving accurate back pan compensation in response to changes in the swing of the crane arm. This is so because there is non-linear relationship between changes in the angular position of the camera arm and the desired angular back pan of the camera head. Thus, these systems require adjustment/calibration of the back pan gain, especially when large changes in the swing of crane arm occur. Consequently, these compensation mechanisms, while potentially helpful in assisting the camera operator in panning the camera head in certain circumstances, may not provide suitable assistance in situations in which the movement of the camera support structure is more complex or when a change in the position of the subject matter occurs.

This patent is subject to a terminal disclaimer.

Automatic pan and tilt compensation system for a camera support structure


A technique is provided for determining service intervals for devices, such as medical equipment. Data related to a device is collected and compared to data from a population of like devices. A service interval may be calculated based on the comparison. The data regarding the population of like devices may be raw quantitative or qualitative data or may be processed data, such as may be used to graph the reliability of the device as a function of some variable such as usage or age, i.e. a reliability curve. The data may representative of the device as a whole or one or more components of the device. Multiple service intervals may be generated for a single device by calculating a service interval for each data source, such as a component or subset of components, of the device. An optimal service interval may then be selected. In addition, the technique may be applied for selection of a service interval for more than one device.

Embodiments of the present invention relate generally to preventative maintenance of devices. Particularly, one embodiment relates to a technique for determining service intervals for medical devices.
In the field of medical equipment, such as imaging systems, patient monitors, and other types of diagnostic and monitoring equipment, regular maintenance is important for providing a high degree of reliability and operability. This equipment may require periodic servicing of components that may wear, be consumed, or become uncalibrated. It is common in the field of medical equipment servicing to provide for both "as needed" servicing (i.e. in response to service requests), and for regular servicing to ensure optimum performance and efficiency of equipment throughout medical institutions.
Current approaches for servicing medical equipment include regular service calls, typically based upon contractual arrangements between service providers and medical institutions. The service providers commonly schedule either on-site service visits or remote servicing, or both, on a regular timed basis. The intervals between such visits are generally determined in rather empirical fashions, however, and may vary widely between service providers, institutions, contracts, regions, and so forth, even for similar types of equipment or usage patterns.
While vital to the proper functioning of hospitals, the regular maintenance of their medical equipment is both time-consuming and costly. Under previous regulation of these institutions, regular maintenance checks of the equipment were required, regardless of whether a device actually needed repair. The regulatory environment has since changed, however, to provide hospitals greater flexibility in developing maintenance schedules. This freedom allows hospitals to extend the time between service visits for a number of devices, resulting in lower maintenance expenses and, thereby, a lower cost of ownership. However, hospitals must still produce maintenance plans that can be justified to patients and to the regulatory authorities.
There is, therefore, a need in the field of medical equipment servicing for an improved technique for determining service intervals for such equipment that would be more closely coupled to the actual need for servicing. There is a particular need for a technique that would permit service intervals to be based upon some criteria or criterion other than simple time intervals.

Customized medical equipment preventative maintenance method and system


Light from a light source (10) is transmitted along an optical fiber (12) through a sensor (14) to opto-electronics (16). The sensor includes a cantilevered beam (20) that flexes in response to acceleration causing its free end (26) to move. Light from the optical fiber (12) is transmitted along an optical fiber to a terminal end (30) thereof and across a gap (34). Light transmitted across the gap is returned to the optical fiber by a mirror (FIG. 2 ) or received by a free end (36) of a second optical fiber (FIG. 1) and conveyed to the opto-electronics. The beam member is configured with an appropriate stiffness that under acceleration, the beam flexes moving its free end sufficiently to change measurably through transmission of light across the gap to the opto-electronics.

The present invention relates to sensors for sensing acceleration and vibration.
Heretofore, the acceleration and vibration sensors have been primarily of electromechanical nature. One prior art acceleration sensor uses a mercury switch which is configured such that the selected acceleration moves the mercury to a position in which it closes an electrical connection between leads. Prior art vibration sensors utilize electrical conductors moving with respect to magnetic fields or piezoelectric elements that produce electric signals proportional to acceleration.
Fiber optic accelerometers of numerous designs are available. The fiber optic systems have numerous advantages over mechanical and electromechanical accelerometers, such as their increased sensitivity and immunity to electrical interference. However, the fiber optic accelerometers tend to be relatively expensive. Moreover, the fiber optic accelerometers are not as amenable to automated manufacture as the prior art electromechanical and electrical acceleration sensors.


A safety hypodermic syringe designed to prevent accidental puncture injuries including a syringe body with a needle assembly having a protective sleeve member which slides over the needle and protects the user from accidental punctures. The syringe is designed so that the sleeve member automatically covers the needle when the syringe is not in use. Disposed between the end of the syringe body and the sleeve member is a biasing means, such as a spring, which forcibly moves the sleeve member downward over the needle covering the distal end thereof. Disposed on opposite sides of the syringe body parallel to the longitudinal axis thereof are two flexible arms which when pressed inward, allow the sleeve member to slide upward so that the user may insert the end of the needle into the skin. When the needle is removed from the skin, the spring forces the sleeve member downward over the end of the needle.

1. Field of the Invention:
This invention relates to hypodermic syringes and, more particularly, to hypodermic syringes designed to prevent accidental punctures.
2. Description of the Related Art:
Blood borne disease transmission has reached epidemic proportion. Medical personnel and patients need protection from accidental needle puncture wounds, as even the slightest injury caused by contact with a contaminated needle may be lethal. Of exceptional concern is the spread of the Acquired Immune Deficiency Syndrome (AIDS). In order for a syringe safety device to be effective, and to be accepted by medical industry personnel, it must simultaneously provide the attributes of complete protection, ease and practicality of use, interchangeable needle capability, and reasonable manufacturing cost.
Previously designed needle wound protection devices have failed to provide all of the aforementioned attributes. Many prior art designs do not provide protection from accidental needle contact through all phases of use. The syringe apparatuses set forth in U.S. Pat. No. 4,932,947 and U.S. Pat. No. 4,929,237 are cumbersome and awkward to use. Safety syringes featuring a needle which is automatically withdrawn when the plunger is driven full stroke do not allow for mixing of medicines, nor do they provide protection from accidental puncture through all phases of use. All other prior art safety syringes' protection mechanisms require use of two hands. Various prior art syringe safety devices do not allow for changing of a hypodermic needle. Medical personnel must be free to safely use hypodermic needles of various lengths and diameters.


A device for feeding electricity under high voltage to a superconductive apparatus is situated in a cryostat. The device comprises two bushings each comprising a first connection terminal situated outside the cryostat, and a second connection terminal situated inside the cryostat. According to the invention, the distance D between the first connection terminals is greater than the distance d between the second connection terminals, the distances D and d being sufficient to avoid electric discharge either between the first terminals or between the second terminals. Advantageously, the cryostat includes an enlargement situated above the two bushings and between them.

A superconductive element or apparatus contained in a cryostat filled with a cryogenic liquid can transport high-current electricity without losses by the Joule effect. However, in order to supply high-current electricity to the superconductive element, it can be necessary to feed it under medium or high voltage. Below, when describing the present invention, the term "medium or high voltage" is used to designate voltages greater than about 50 kilovolts (kV).
Electricity is conveyed from a source situated in ambient air, and thus at ambient temperature, to the superconductive element situated in a cryostat, and thus at cryogenic temperature, by using a feed-through device known as a "bushing", which mainly comprises a central electrical conductor surrounded by an insulating sheath. A bushing must accomplish the temperature transition over a reasonable length while ensuring that losses by thermal conduction are low so as to avoid too great a flow of heat being transmitted into the cryogenic liquid, thereby leading to it boiling. In addition, the bushing must be capable of conveying electricity at high current and it must be capable of withstanding high voltage.
In order to feed a superconductive element with electricity, it is necessary to use one bushing for current inflow and another bushing for current outflow. If the feed voltage is high, there is a risk of electrical discharge occurring between the two ends of the two bushings that are situated in the ambient air. In other words, the electric field between those two ends can become great enough to lead to an electric arc forming between the two ends that are situated in air, i.e. to a "breakdown" in air. That phenomenon occurs essentially when there is a fault in the superconductive element, or when its current-carrying capacity is exceeded, e.g. during a current surge on the network. Under such circumstances, electrical continuity between the two bushings is interrupted, at least temporarily, meaning that one of the bushings remains at the high voltage potential while the other is to be found at a potential close to ground potential. Spacing the two bushings apart by a distance that is sufficient to avoid a breakdown occurring, e.g. a distance of several meters, cannot be envisaged because of the dimensional constraints imposed on the cryostat containing the superconductive element. The size of the cryostat is limited for reasons of cost, both manufacturing cost and running cost. The present invention proposes a device that makes it possible to avoid an electric discharge appearing.
Another problem associated with feeding electricity that might be at high current and under high voltage, lies in the temperature of the cryogenic fluid being raised locally, and thus to gas forming, which might be due to a defect in the superconductive element, or more simply to the nature of said element. For example, if the superconductive element is a current limiter immersed in liquid nitrogen, the current limiter ceases to be superconductive if the magnitude of the current carried thereby exceeds a certain threshold. The current limiter then heats up by the Joule effect, thereby leading to local boiling of the liquid nitrogen, and thus to bubbles of nitrogen gas forming. Since nitrogen in gaseous form is much less electrically insulating than nitrogen in liquid form, an electric discharge can then occur within the cryostat, e.g. between the two ends of the two bushings that are situated inside the cryostat. An embodiment of the present invention provides a solution to this problem.

Device for feeding electricity to a superconductive apparatus under medium or high voltage


Floating roof storage tank systems and related methods are disclosed. The disclosed systems include a storage tank, a floating roof, and a plurality of acoustic sensors. The storage tank has one or more walls defining an interior space and the floating roof is configured to move vertically within the interior space. The acoustic sensors are levelly mounted along a horizontal plane on the one or more walls of the storage tank. One or more signals received by at least a portion of the plurality of acoustic sensors are used to determine a tilt angle of the floating roof.

Above ground storage tanks can be used to store liquids, solids, or gases. Outdoor above ground storage tanks typically either have a fixed roof and/or a floating roof that lays on the surface of the stored material and rises and falls as the amount of stored material increases or decreases. Floating roof storage tanks usually take the form of an open-topped cylindrical tank shell (made of an impermeable material, such as steel) outfitted with an internal roof sized to fit snugly within the cylindrical shell and to float on the surface of the liquid or other material stored therein. A unique advantage of floating roof storage tanks is that there is no vapor space in a floating roof tank, as opposed to a fixed roof tank, which accommodates vapor above a stored liquid. Floating roof tanks thus can greatly reduce or eliminate evaporative loss of any stored liquid. Floating roof storage tanks can be particularly useful for storing large quantities of petroleum products, such as crude oil or condensate.
However, a storage tank with a floating roof can experience tilting of the floating roof, either due to mechanical failure or excess liquid pooling on top of the floating roof. Under normal conditions, fluids (such as rainwater) deposited on top of a floating roof will be drained off. However, if any environmentally restricted material is present in the runoff, the contaminated fluid cannot be drained to the open ground. Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies of current above ground storage tanks, including vulnerability to undetected floating roof tilt and inability to determine if runoff is contaminated.

Systems and methods for determining floating roof level tilt and characterizing runoff


The present invention provides for an apparatus to locate a blood vessel puncture having a bleed back entrance port near a first end, a bleed back exit port near a second end; and a lumen extending between the bleed back entrance port and the bleed back exit port, wherein said bleed back entrance port has a diameter substantially equal to or greater than the lumen diameter. The present invention further provides for a method for locating a blood vessel puncture by inserting a locator into a blood vessel lumen, the locator having a bleed back entrance port at a first end, a bleed back exit port at a second end, and a finger adjacent the bleed back entrance port, observing a blood flow out of the bleed back exit port, and withdrawing the locator out of the blood vessel lumen until the finger contacts the blood vessel wall.

A large number of diagnostic and interventional procedures involve the percutaneous introduction of instrumentation into a vein or artery. For example, coronary angioplasty, angiography, atherectomy, stenting of arteries, and many other procedures often involve accessing the vasculature through a catheter placed in the femoral artery or other blood vessel. Once the procedure is completed and the catheter or other instrumentation is removed, bleeding from the punctured artery must be controlled.
Traditionally, external pressure is applied to the skin entry site to stem bleeding from a puncture wound in a blood vessel. Pressure is continued until hemostasis has occurred at the puncture site. In some instances, pressure must be applied for up to an hour or more during which time the patient is uncomfortably immobilized. In addition, a risk of hematoma exists since bleeding from the vessel may continue beneath the skin until sufficient clotting effects hemostasis. Further, external pressure to close the vascular puncture site works best when the vessel is close to the skin surface but may be unsuitable for patients with substantial amounts of subcutaneous adipose tissue since the skin surface may be a considerable distance from the vascular puncture site.
There are several prior art devices that try to overcome the disadvantages of the traditional external pressure application. For example, there are devices that place a hemostat within the bloodstream of the vessel, within the wall of the blood vessel, or adjacent to the wall of the blood vessel puncture site to close the puncture. However, reliance is on tactile sensation alone to indicate to the surgeon the proper placement of the puncture closing instrumentation. Other prior art references require a separate device for locating the blood vessel puncture site which is must then be removed for insertion of a second device to expel a hemostat. Still other prior art devices use bleed back ports to locate the blood vessel puncture site in conjunction with other devices such as a foot plate placed against the blood vessel wall or closure devices with anchors. However, in some of these prior art devices a surgeon is then required to use sutures and/or needles to close the blood vessel puncture. Moreover, in some of the prior art devices, external pressure applied at the surface of the skin may still be required.
Other devices utilize a dilator having a bleed back entrance port and a bleed back exit port. However, current dilators used today, as shown in FIG. 6, require the blood to traverse through a long, narrow, and often restricted lumen before exiting the bleed back exit port. This results in poor visual bleed back, which compromises the accuracy of the blood vessel puncture site as further discussed below with reference to FIG. 6. Moreover, since the blood must traverse through a long and thin lumen, the blood may quickly and easily clot further restricting the blood flow out of the bleed back exit port.
Thus, there is still a need for an apparatus and method to efficiently and easily locate a blood vessel puncture site.


A cutting unit for pipes which includes a laser beam which is reflected by a series of mirrors positioned adjacent the circumference of a pipe and wherein the mirrors are mounted on the ends of movable arms pivotally connected to one another and wherein one of the arms rotates around a pipe to be cut and the other arm serves as an optical and mechanical connection between a laser source and the arm which rotates.

1. Field of the Invention
The invention relates to the sector of continuous pipe production and cutting.
In particular, it concerns the tools and devices for the cutting of continuous pipes in given lengths during the advancement of the pipe that is being produced.
2. History of the Related Art
Pipes are often produced through extrusion, if they are made of plastic, or through bending and welding, if they are made of metal. The pipe manufactured in this way is thus continuous and its length increases as production proceeds.
Therefore, it is necessary to cut it in given lengths for its storage, transport and final utilization.
At present these pipes produced in continuous lengths are cut by means of a mobile cutting device installed on a trolley and provided with blades or discs. The mobile device anchors to the pipe and follows it during its advancement, while a blade or disc cuts the pipe. As soon as the pipe is cut, the device rapidly goes back to its original position and is thus ready for the successive cutting operation.
These cutting devices present several drawbacks that are mainly due to the long cutting times and to the tool used for cutting.
After a certain number of cutting operations, the tool wears out and does not perform the successive cuts correctly, requires more time for cutting and leaves the pipe edges rough and imprecise. When the cutting tool reaches a considerable degree of wear, it is necessary to stop production in the whole plant in order to replace it.
Obviously, this affects the quantity and quality of the produced pipes negatively.

Cutting unit for pipes produced in continuous lengths


A lady's undergarment is provided which has a front neck hole seam that is generally W-shaped and has a raised middle section which falls in between the user's breasts. The undergarment has a lower opening that is defined by a generally straight back hem and a bevel front hem which has a lowermost portion that is cut at an angle. The undergarment may include one strap or two straps or be strapless. A collar may be attached to the undergarment. The back hem of the lower opening of the undergarment may be sufficiently long to be passed between the legs of the user and extended upwards to be attached to the undergarment. The undergarment may include cushioning means at several different sections of the undergarment. Undergarments that are designed for women who are missing one or both breasts may have cushioning to line area where breast is missing. The undergarment may include a flap between the folds of the breasts. A basically triangular patch may be attached to the vicinity of and is designed to closely silhouette the front neck hole seam. Finally, the undergarment may be combined with and attached to a brassiere to be worn by the user as one unit.. The undergarment may be attached to and may include a girdle. The girdle may be combined with and attached to the undergarment as a padding or as an extension of the undergarment. If attached to the undergarment as an extension, the girdle may form legs for the undergarment or may form openings for passage of legs of user into and out of the undergarment.

This invention relates to a lady's undergarment, at least part of which falls underneath one or more other undergarments (such as brassieres, girdles, braces, pantyhose etc.) which are being worn by the lady.
There is no garment on the market today that gives a woman relief from the discomforts associated with wearing a brassiere and some other undergarments. Brassieres and some other undergarments often slide, chafe, pinch, dig, push, bind and squeeze the body. Women with relatively large breasts, weight problems or other sensitivities (e.g. due to sunburn, surgery, braces, pregnancy and skin infections) have greater degrees of discomfort. Women with relatively large and heavy breasts are exposed to additional discomforts due to perspiration existing under and between the folds of the breasts. Some women stuff tissues in their cleavage area in order to absorb moisture. However, tissue becomes uncomfortable and soggy when wetted. The problems encountered by women with relatively heavy breasts are further compounded by the weight of the breasts. Straps of brassieres cut into the shoulders of heavy-breasted women, creating pain and deep ridges in the shoulders. Detachable pads can be used to wrap around straps of brassieres, but these are difficult to adjust, easily slip and are easily lost during washing and in drawers. A problem associated with many lady's undergarment is that they are not adjustable to various body shapes. A poorly adjustable undergarment leaves folds and bulk that are not only uncomfortable, but are visible through outer garments.
Some efforts have been made to provide comfortable brassieres. However, brassieres are expensive and many women are brand conscious and reluctant to change. An undergarment which can provide comfort for the user when wearing a brassiere is desirable.
This invention provides an undergarment that minimizes the discomforts associated with brassieres and with some other undergarments, that absorbs moisture existing under and in the folds of a lady's bosom, that cushions the areas of the lady's body which are under the pressure of other pieces of undergarments, that provides increased support for the breasts, that minimizes discomforts associated with the weight of the breasts, that provides cushion linings for missing breasts, that is adjustable in size, shape and form, that does not create new discomforts and that remains virtually invisible under clothing.
This invention also provides firm control for, supports and shapes various parts of the body that are covered by sections of the undergarment that are lined by a girdle.


A medical device implant for the left atrial appendage of a patient's heart to prevent strokes. The device includes a cap that overlies the opening of the LAA connected to a bulb in the LAA. Discontinuous segmented sails attached to the cap promote tissue growth over the device. The device maybe repositioned and redeployed during implantation.

It is widely understood that the occlusion of the left atrial appendage of the human heart will prevent strokes. The mechanism of action is that clots present within the left atrial appendage can become entrained into the general circulation and be transported to the brain where the clots can occlude arterial vessels causing an ischemic stroke.
Devices that have received significant clinical study include the "Plaato" device described in U.S. Pat. No. 6,152,144 among others, and the "Watchman" device described in U.S. Pat. No. 6,689,150 among others. Each of these clinically tested devices lies wholly within the left atrial appendage and includes a membrane that spans the opening or ostium of the left atrial appendage. The Watchman device is typically porous and in the Plaato device the membrane is impervious to the passage of blood. Additionally, the Watchman device uses a series of barbs or prongs which enter the tissue surrounding the ostium of the left atrial appendage to help secure the device during the acute phase of implant.
Although both of these devices appear to be successful, they each have shortcomings and drawbacks, which suggest that additional development is required for a widely acceptable and successful left atrial appendage device.

Redeployable left atrial appendage occlusion device


A method for driving a simple matrix type display device includes the steps of: applying a data voltage corresponding to values obtained by an orthogonal transform of input data to the data electrodes; applying a scanning voltage to the scanning electrodes, the scanning voltage corresponding to an orthogonal function used for the orthogonal transform; and reproducing the input data by an orthogonal inverse transform of the data voltage on the display panel, wherein the step of applying the scanning voltage includes the steps of: applying a scanning selection pulse signal having at least two levels to the scanning electrodes as a scanning voltage; and fixing the scanning selection pulse signal to an unselected level during a first period, a second period, or both of the first and second periods, the first period being defined as a period from the beginning of the data output until a predetermined time later in a data voltage output period, and the second period being defined as a period from a predetermined short time before the completion of the data output until the completion of the data output in the data voltage output period.

1. FIELD OF THE INVENTION
The present invention relates to a liquid crystal display device and to a method for driving a display device. In particular, the present invention relates to a driving circuit for generating a driving waveform that provides uniform display quality and peripheral circuitry thereof.
2. DESCRIPTION OF THE RELATED ART
In recent years, there has been increasing demand for display devices capable of displaying a large amount of information at the same time due to the rise of a highly information-oriented society. CRT (Cathode Ray Tubes) displays have conventionally been used for such purposes. However, CRTs are generally large and tend to consume a large amount of power, making them unsuitable for use other than as desk-top devices. On the other hand, flat display devices such as LC (liquid crystal) display devices are attracting much attention because of their thinness and light weight.
LC display devices were originally developed as display devices for calculators, watches, etc. However, current LC display devices typically include a matrix of scanning electrodes and data electrodes, and are capable of displaying images on a large screen owing to progress in technology concerning STN (Super-Twisted Nematic) liquid crystal and TFT (Thin Film Transistor) elements.
Such matrix type LC display devices can be classified into simple matrix type display devices and active matrix type display devices in terms of their driving methods.
Active matrix type LC display devices, which are typically driven by using TFT elements or MIM (Metal Insulator Metal) elements, include a matrix of scanning electrodes and data electrodes with switching elements of TFTs, diodes, and the like located at the respective intersections of the scanning and data electrodes. A display is realized by controlling such switching elements so as to apply a voltage independently to portions of liquid crystal corresponding to the respective pixels. In such active matrix type LC display devices, the LC is usually driven in its TN (Twisted Nematic) mode, thereby achieving high contrast and a quick response at the same time. Since the voltage to be applied to each portion of LC corresponding to a pixel can be independently controlled, it is relatively easy to display intermediate gray scale tones.
On the other hand, a typical simple matrix type LC display device driven in a STN mode includes an LC layer interposed between glass substrates having a matrix of electrodes formed on the surface thereof so as to conduct display by utilizing the steep characteristics of the electrooptical effects of LC, i.e., the change in the optical characteristics of LC when an electric field is applied thereto. As a result, simple matrix type LC display devices require a relatively simple panel structure and production process, and therefore are more preferable in terms of cost than active matrix type LC display devices.
Simple matrix type STN LC display panels have conventionally been driven by a time-divided method (or "duty driving") which is also referred to as a linearly sequential driving method. Since a plurality of pixels are coupled to one electrode in an active matrix type LC display device, the applied voltage has time-divided pulses. Generally, scanning electrodes are linearly sequentially scanned at a frame cycle of 20 ms or less. A large selection pulse is applied to each scanning electrode once per frame, in synchronization with which a data signal is applied via a data electrode.
Since conventional STN LC display devices have a relatively low LC response speed, e.g., 300 ms, the LC can respond in accordance with the ON/OFF ratio of the effective voltage applied in linearly sequential driving, thereby achieving a practical contrast level. However, once quick response is realized in STN LC display devices (such that moving images can be displayed thereby) by reducing the viscosity of LC and/or reducing the thickness of the LC layer, etc., the linearly sequential driving results in a noticeable degradation of contrast due to a so-called frame response phenomenon described below.
Liquid crystal is generally considered to respond to the effective values (rms) of the driving waveform. Assuming that an effective voltage of V.sub.on (rms) is applied to a selected electrode and an effective voltage of V.sub.off (rms) is applied to an unselected electrode, a driving margin (V.sub.on (rms) / V.sub.off (rms)) takes the maximum value: ##EQU1## based on the voltage averaging method. In the above equation, N represents the number of scanning lines, and 1/N represents the duty ratio. Usually V.sub.off is set equal to a threshold voltage V.sub.th of the LC.
A liquid crystal panel having very quick response tends to deviate from such an inherent response mode (i.e., responding to effective values(rms)) and instead responds to the driving waveform itself, so that the transmittance value fluctuates corresponding to each frame. This phenomenon is referred to as a "frame response phenomenon".
Because of the frame response phenomenon, the off-transmittance increases even if the V.sub.off (for the unselected pixels) is set equal to V.sub.th. In the selected pixels, the actual transmittance is reduced although the optimum effective voltage of V.sub.on (rms) is being applied. Thus, the conventional linearly sequential driving method, when applied to a high-speed STN LC panel, can remarkably deteriorate the display contrast thereof.
Therefore, in order to maintain the optical contrast in a high-speed and high-resolution STN LC panel, it is necessary to drive the LC so as to suppress the frame response phenomenon.
On the other hand, a driving method called a multiple scanning line simultaneous selection driving method (also referred to as "active driving") has been proposed, which generates scanning selection pulses from an orthogonal matrix. By the active driving method, a plurality of scanning lines are simultaneously selected during one frame period in order to control the frame response phenomenon, thereby supplying a number of small scanning selection pulses for one scanning electrode during each frame period. Thus, the active driving method utilizes the cumulative response effect of LC so as to reconcile rapid response and high contrast.
According to the active driving method, input image data is subjected to an orthogonal transform process using an orthogonal matrix, and a signal corresponding to the transformed data is supplied from the data electrode side. From the scanning electrode side, scanning voltage pulses are applied corresponding to the elements of column vectors of the orthogonal matrix used for the transform. An orthogonal inverse transform performed on the panel side for the input image data reproduces the input image.
Active driving methods can be generally classified into an active addressing method (hereinafter referred to as the "AA method") and a multiline selection method (hereinafter referred to as the "MLS method"), although both are based on the same principle. For detailed descriptions of the AA method, see T. J. Scheffer, et al., SID' 92, Digest, p.228; Japanese Laid-Open Patent Publication No. 5-100642; and the like. For detailed descriptions of the MLS method, see T. N. Ruchmongathan et al., Japan Display 92, Digest, pp.65-68, Japanese Laid-Open Patent Publication No. 5-46127, and the like.
FIGS. 1A to 1C show examples of respective orthogonal functions used for the AA method and two variants of the MLS method.
The AA method uses an orthogonal function such as the WALSH function shown in FIG. 1A. Positive or negative voltages (i.e., voltages corresponding to the elements 1! or -1! of the orthogonal matrix) are simultaneously applied to all of the scanning electrodes.
The MLS method, as in the conventional duty driving method, has unselected periods of scanning pulses. The elements 0! in the orthogonal matrices shown in FIGS. 1B and 1C correspond to the unselected periods. The MLS method has an advantage of using mathematical operations of a much smaller scale than the AA method because when an element of the matrix is 0!, the result of an orthogonal transform with given data (i.e., multiplication/addition) always becomes 0.
The MLS method is further classified into a dispersion MLS method (FIG. 1B) in which the selection pulses of the orthogonal function are dispersed through-out one frame period, and a non-dispersion MLS method (FIG. 1C) in which selection pulses of the orthogonal function are grouped into blocks. An example of the dispersion MLS method is a SAT (Sequency Addressing Technique) disclosed in Japanese Laid-Open Patent Publication No. 6-4049. An example of the non-dispersion MLS method is an IHAT (Improved Hybrid Addressing Technique) disclosed in T. N. Ruchmongathan et al., IDRC 1988 pp.80-85.
An intrablock dispersion MLS method (Japanese Patent Application No. 6-291848), in which the selection pulses are dispersed within each of a plurality of blocks into which one frame is divided, is classified as a non-dispersion MLS method in terms of its fundamental operation sequence, and therefore requires a smaller memory capacity than does the dispersion MLS method. However, hereinafter the intrablock dispersion MLS method and the dispersion MLS method will be collectively referred to as "the dispersion MLS method" because the intrablock dispersion MLS method is capable of reducing the number of simultaneously selected lines to that required by the dispersion MLS method.
In general, the dispersion MLS method is considered to provide the same effect, by using a smaller number of selected lines, as that of the non-dispersion MLS method. In fact, an experiment in which a VGA-class LC panel having a response speed of 150 ms was driven while being split into upper and lower halves so as to display an image at a frame frequency of 60 Hz showed that the dispersion MLS method only requires 7-15 lines to be simultaneously selected in order to attain the same contrast level as that attained by the AA method, which selects all of the 240 scanning lines. On the other hand, the non-dispersion MLS method required 60 or more lines to be simultaneously selected in order to attain the above-mentioned contrast level.
However, the memory capacity required for the orthogonal transform operation depends on the calculation order of the orthogonal transform operation, i.e., the specific orthogonal transform matrix chosen. Thus, the non-dispersion MLS method has an advantage in that it only requires a memory capacity corresponding to the number of selected lines, whereas the AA method and the dispersion MLS method fundamentally require a memory capacity for storing data corresponding to at least one entire frame. Therefore, neither the dispersion MLS method nor the non-dispersion MLS method is superior.
However, when contemplating a system which primarily aims to maintain a satisfactory contrast level, a smaller operation scale is desirable because it leads to lower power consumption. Therefore, the dispersion MLS method is considered the most practical among the various active driving methods for rapid STN LC panels.
As described above, among the various active driving methods for high-speed STN LC panels, the dispersion MLS method is considered to have the optimum balance between the contrast level and circuit scale.
However, the inventors discovered upon driving a high-speed STN LC panel by the dispersion MLS method, that the dispersion MLS method has problems unique to itself, e.g., degradation in display quality such as a double-image (ghost) phenomenon and display unevenness occurring in a horizontal zone as described below. These problems do not belong to the duty driving method.
The above-mentioned problems are ascribed to nothing but the operation principle of the dispersion MLS method, i.e., all the scanning lines are divided by the number of selected lines into a plurality of subgroups in such a manner that the scanning selection waveform is dispersed within each subgroup, as described below.
FIG. 2 shows an exemplary orthogonal function matrix used for the dispersion MLS method. In this case, there is a total of 8 scanning lines to be selected, two of which are simultaneously selected, and there are 8 data electrodes. In theory, the elements +1! and -1! of the orthogonal matrix correspond to scanning selection pulse potentials +V.sub.r and -V.sub.r, respectively, and the element 0! of the orthogonal matrix corresponds to a unselected potential V.sub.com (=0). Data shown in FIG. 3 is to be displayed by using the orthogonal function in FIG. 2. FIG. 4 shows the waveform of pulses to be applied to the scanning electrodes by a common driver IC on the scanning side for driving the LC.
In an actual LC panel module, the electrode resistance of the scanning electrodes e.g., those of ITO (Indium Tin Oxide), the ON resistance of the scanning-side driver IC, and the capacitance component of the LC itself form a low-pass filter, which cuts off the harmonics components contained in the steep rises and steep falls of the scanning pulses. As a result, the waveform of the voltage to be applied to the scanning electrodes is distorted (or blunted) as shown in FIG. 5 in actual operation.
Among the distortions of the waveform of scanning selection pulses, the distortion occurring at the foot of the falling edge of each pulse, which causes some degradation in the display quality, will be first described.
When such distortion occurs, the fall of the +V.sub.r pulse (or the rise of the -V.sub.r pulse) has some delay so that each scanning selection pulse is applied to the same scanning electrode for a period slightly longer than the intended period, as shown in FIG. 5.
With respect to the scanning electrodes S1 and S2, the first selection pulse in one frame is to be applied during a period t1. However, the above-mentioned distortion of the scanning selection pulse waveform is applied as a secondary selection pulse to the scanning electrodes S1 and S2 for a period of .DELTA.t in addition to the period t1. The period .DELTA.t exists within a period t2, during which a selection pulse is to be applied to the next scanning electrodes S3 and S4.
In other words, a data signal from the segment side is applied (as ON voltage) to portions of the LC corresponding to the scanning electrodes S1 and S2 during not only the intended period t1 but also the period .DELTA.t within the period t2, during which the selection pulse is to be applied to the scanning electrodes S3 and S4. As a result, the image data to be reproduced at positions corresponding to the scanning electrodes S3 and S4 are reproduced so as to be slightly visible at positions corresponding to the scanning electrodes S1 and S2, thus creating a ghost image. In summary, any waveform distortion occurring at the falling edge of a pulse allows an image which should be reproduced only under a selected number of scanning electrodes to be also reproduced under adjoining scanning electrodes, thereby resulting in a ghost or a faint image of the same pattern appearing at a position slightly shifted from the original image.
It may seem that the scanning electrodes S7 and S8 are free from the ghost phenomenon because they are located at the end of the 8 scanning electrodes, and also physically at an end of the LC panel. However, since the waveform distortion of the scanning selection pulse to be applied to the scanning electrodes S7 and S8 exists within the period during which the scanning electrodes S1 and S2 are selected, the image data to be reproduced at positions corresponding to the scanning electrodes S1 and S2 appear as a ghost at positions corresponding to the scanning electrodes S7 and S8. However, when the scanning goes back from the scanning electrodes S7 and S8 to the scanning electrodes S1 and S2, the function data (i.e., the orthogonal function) changes so that not just a simple ghost of the image to be reproduced at the scanning electrodes S1 and S2 but a reversed image (i.e., white portions appearing black and vice versa) of the ghost often appears at the scanning electrodes S7 and S8.
As a result, the display device data of FIG. 3 is likely to appear as in FIG. 6.
In the case of the duty driving method, scanning electrodes are sequentially selected one by one, so that the ghost of an image to be reproduced at the intended scanning electrodes, occurring due to waveform distortion at the falling edge of the scanning selection pulse, appears in principle at scanning electrodes next to the intended scanning electrodes, rather than at a position substantially away from the intended scanning electrodes as in the case of the active driving method. Moreover, the duty driving method selects a scanning electrode only once in every frame, so that any waveform distortion of a scanning selection pulse within one frame has a smaller influence than in the case of the active driving method, which selects a scanning electrode a plurality of times in every frame. Furthermore, the duty driving method is typically adopted for a low-speed panel, which has a thicker LC layer than that of a high-speed panel, that is, the capacitance component is smaller than in the case of a high-speed panel. Therefore, the influence of waveform distortion becomes even smaller. Thus, the double-image phenomenon of an original image being accompanied by a ghost image is not as prominent in the duty driving as in the active driving.
Next, the degradation in display quality due to waveform distortion occurring at the rising edge of a pulse will be described. The following description illustrates a case where the data signal is intended for displaying an all-white image.
When an orthogonal transform is performed for a normally-black LC panel by a binary digital system, white data corresponds to "1" (i.e., High) and black data corresponds to "0" (i.e., Low). Elements +1! and -1! correspond to "1" (i.e., High) and "0" (i.e., Low), respectively.
An orthogonal operation by this system is performed by taking an Exclusive OR of each column vector of the data and the function, and adding the results of the Exclusive ORs by an adder, the result of the addition defining a data signal corresponding to display data (i.e., a signal to be applied to the data electrodes). Accordingly, it is presumable that the operation result has a large dependence on the function when the data is all-white, i.e., all "1" (High).
Now a case will be contemplated where the orthogonal function matrix in FIG. 2 is used for an LC panel system composed of 8 scanning electrodes and 8 data electrodes (as in the above description of the double-image phenomenon). Herein, the display data is assumed to be all-white. The signal waveform on the data side of the circuitry in this case is constant irrespective of the data electrodes, as shown in FIG. 7. As seen from FIG. 7, the data signal waveform drastically varies only at a boundary between the period t4 and the period t5, at which the orthogonal function changes.
In the duty driving method and the MLS methods, unselected periods are predominant in the scanning signal waveform for every frame. Therefore, the change in the data signal on the segment side is induced to the common side, thereby appearing as an induction distortion in the waveform of the scanning signal.
In this exemplary case, the data signal changes only once in one frame, i.e., at the boundary between the periods t4 and t5 as shown in FIG. 8, and therefore does not cause induction distortion in any other periods in the frame. In other words, among scanning selection pulses, only the rise of the selection pulse applied to the scanning electrode S1 during the period t5 and the fall of the selection pulse applied to the scanning electrode S2 during the period t5 are influenced by the induction from the segment side (data electrodes).
Specifically, the selection pulse voltage for the scanning electrode S1 has a small amount of waveform distortion relative to the distortion of selection pulses for the scanning electrodes S3 to S8, whereas the selection pulse voltage for the scanning electrode S2 has a large amount of distortion relative to the waveform distortion of the selection pulses for the scanning electrodes S3 to S8. However, the scanning selection pulses for scanning electrodes other than the scanning electrodes S1 and S2 are not influenced by the induction from the segment side. For similar reasons, the selection pulse voltage level for the scanning electrodes S1 and S2 largely decreases at the beginning of the period t1 due to waveform distortion.
As a result, the waveform distortion occurring at the rising edge of the scanning selection pulses for the scanning electrodes S1 and S2 in the periods t1 and t5 is different (i.e., more or less drastic) from the waveform distortion occurring at the rising edge of the other scanning selection pulses. Therefore, the effective values of the applied voltages to the pixels (LC) corresponding to the scanning electrodes S1 and S2 become smaller than the effective values of the voltages applied to the pixels (LC) corresponding to other scanning electrodes.
Because of the difference between the effective voltages corresponding to the scanning electrodes S1 and S2 and the effective voltages corresponding to the scanning electrodes S3 to S8, the illuminance of a portion corresponding to the scanning electrodes S3 to S8 is lower than the illuminance of portions corresponding to the other scanning electrodes, thereby resulting in a horizontal zone (corresponding to the two scanning electrodes) of uneven or reduced illuminance. In summary, any difference between the waveform distortion at the rising edge of a scanning selection pulse corresponding to a point of change in the orthogonal function and the waveform distortion at other portions of the orthogonal function results in a horizontal zone (corresponding to the number of selected scanning electrodes) of unevenness in illuminance.
Although the effective values of the voltages applied to the pixels corresponding to the scanning electrodes S1 and S2 are different from each other in the above description, they become substantially equal in actual driving because of processes such as averaging the frequency of scanning selection pulses and rotation of the orthogonal function for cancelling the DC component.
Because of the above-mentioned difference in the waveform distortion at the rising edge of each scanning selection pulse and because of the waveform distortion at the falling edge of the scanning selection pulse, a zone of display unevenness as shown in FIG. 9B is observed when the image data shown in FIG. 9A is displayed on a display panel of 8.times.8 display pixels by using the orthogonal function of FIG. 2.
Thus, the dispersion MLS driving method has the above-mentioned problem of display unevenness due to the operation principle thereof, i.e., all the scanning lines are divided by the number of selected lines into a plurality of subgroups in such a manner that the scanning selection waveform is dispersed within each subgroup.

Liquid crystal display device and method for driving display device


A wiring harness (1) includes a copper wire (3), an aluminum wire (4) and a ground terminal (2) connected to these wires. The ground terminal (2) includes two wire-side terminal portions (11), (12). A conductor barrel (11b) of the first wire-side terminal portion (11) is crimped to have such a first crimping height (H1) that the conductor barrel (11b) can come into contact with a surface of a conductor (3a) of the copper wire (3). A conductor barrel (12b) of the second wire-side terminal portion (12) is crimped to a conductor (4a) of the aluminum wire (4) to have such a second crimping height (H2) lower than the first crimping height (H1) that the conductor barrel (12b) can come into contact with the conductor (4a) of the aluminum wire (4) through an oxide film (4d) covering a surface of the conductor (4a).

1. Field of the Invention
The present invention relates to a terminal-wire assembly with a plurality of wires mixedly including a copper wire and an aluminum wire.
2. Description of the Related Art
Conventionally, a ground connection terminal is connected to an end of a ground wire as described in Japanese Unexamined Patent Publication No. H10-208815 to connect the ground wire included in an automotive wiring harness to a ground section of a vehicle. The ground connection terminal includes a wire-side terminal portion and a ground-side terminal portion. The wire-side terminal portion is shaped to be connectable to the end of the ground wire. Specifically, the wire-side terminal portion includes one crimping portion such as a conductor barrel to be crimped to a conductor exposed to outside at the end of one ground wire. The ground-side terminal portion is connectable to the ground section on a wall surface of a vehicle body.
Copper wires whose conductors are made of copper are frequently used as wires such as ground wires. In recent years, wires made of metals different from copper such as aluminum wires including a conductor made of aluminum have been used.
Here, the ground connection terminal as described above includes one crimping portion connectable to one ground wire, but it is difficult to collectively connect a plurality of wires mixedly including a copper wire and an aluminum wire to a ground section with high reliability. Specifically, a surface of a conductor of an aluminum wire is normally covered with an oxide film. Thus, the crimping portion needs to come into contact with the conductor made of aluminum by breaking the oxide film. Thus, a crimping degree higher than that for copper conductors is required. Further, since copper and aluminum differ in hardness, crimped states tend to vary. Thus, in the case of crimping the crimping portion to the aluminum wire at the same crimping degree as that in the case of crimping the crimping portion to the copper wire, it is difficult to maintain connection reliability.
Further, in the case of collectively fastening both the copper wire and the aluminum wire by one crimping portion, electrolytic corrosion may occur between different types of metals.
In the case of individually crimping a plurality of ground terminals to a copper wire and an aluminum wire, the number of the ground terminals increases. Thus, it is difficult to collectively connect a plurality of ground terminals to a ground section in a limited space.
The present invention aims to provide a terminal-wire assembly in which a plurality of wires mixedly including a copper wire and an aluminum wire are collectively connected to a predetermined section with high reliability.


The invention enables to estimate the frequency offset introduced by a transmission medium based on the transmission of a known sinusoidal-frequency signal. Two samples out of phase by Π/2+p.2Π where p is an integer are multiplied to obtain a trigonometric function of said frequency offset. The estimate thus obtained is advantageously applied for correcting test signals received during a learning period preceding a transmission period between a transmitter and receiver. The estimate is also applicable for initializing adaptive algorithms for recovering the timing or echo cancellation at the level of the receiver. Any transmission system that utilizes one or various carriers and enables to transmit a sinusoidal signal at a given instant, notably Recommendation V34 of the CCITT.

The invention relates to a transmission system between at least a transmitter and at least a receiver via a transmission medium, likely to cause a frequency offset and an attenuation, said emitter comprising emitting means for emitting a sinusoidal signal of known frequency, and said receiver comprising receiving means for receiving said sinusoidal signal and estimation means for estimating said frequency offset from said received sinusoidal signal. The invention likewise relates to a receiver intended to be used in such a system, more particularly, a modem.
The invention also relates to a method of estimating the frequency offset caused on a carrier by a transmission medium, comprising a transmission step of a sinusoidal signal of known frequency. The invention also relates to a computer program implementing said frequency offset estimating method. The invention finally relates to a method of testing a transmission medium likely to cause a frequency offset, said method comprising steps of transmitting known test signals, receiving said test signal, and analyzing received test signals to derive properties of said medium therefrom.
The invention is applied to all the transmission systems that utilize one or various carriers and enable to transmit a sinusoidal signal at least at a given instant. The invention more particularly applies to modems, notably in accordance with Recommendation V34 of the CCITT.
U.S. Pat. No. 5,206,886 describes a multicarrier transmission system that includes estimation means for estimating the frequency offset introduced by the transmission medium. The estimate obtained is used at the beginning of the data transmission phase to initialize the adaptive algorithms for recovering the carrier of the receiver. The proposed estimation method is a complex adaptive method based on the transmission of two sinusoidal signals having known frequencies f1 and f2. Upon reception, these signals are separated by filtering and the phases xcfx861(t) and xcfx862(t) are calculated as a function of time (this calculation causes a calculation of the arctangent to be performed for each signal and each considered instant). The functions are then analyzed to obtain said estimate.
The invention notably has for its object to propose another, simpler method of estimating the frequency offset caused by the transmission medium.
This object is achieved with the transmission system as defined in the opening paragraph and characterized in that said estimation means comprise sampling means for sampling said received sinusoidal signal, phase shifting means for producing Π/2+p.2Π phase shifted samples of said received sinusoidal signal, where p is an integer, first calculation means for calculating said attenuation from at least two of said phase shifted samples, and second calculation means for calculating said frequency offset from at least two of said phase shifted samples and from the calculated attenuation.
The proposed method is particularly simple and thus cost-effective in terms of processing power. In an embodiment which is particularly easy to implement, first calculation means comprise means for calculating a mean value of an addition of the square value of two Π/2 phase shifted samples.
When the receiver comprises a reception filter, second calculation means use two Π/2+p.2Π phase shifted samples where p is chosen so that said two samples are decorrelated. In an advantageous embodiment, the second calculation means comprise means for calculating a mean value of a product of said samples so as to provide a trigonometric function of said offset. When the received signal is not filtered, it is advantageous to chose p=0, because in this case, the invention implies only a single calculation of a trigonometric function.
The invention likewise proposes another use of an estimate of said frequency offset. Indeed, according to the invention, a system as described in the opening paragraph, which comprises test means for testing said transmission medium notably by transmitting, receiving and then analyzing known test signals so as to derive therefrom properties of said medium, also includes correction means for correcting said offset during the reception of at least certain of said test signals.
It is thus possible to reduce the effect of the frequency offset on the modeling of the transmission medium, more particularly on the evaluation of the signal-to-noise ratio. This evaluation of the signal-to-noise ratio is notably used for choosing at the transmitter end a transmission rate on the transmission medium. The invention particularly enables to avoid that the frequency offset introduced by the medium is interpreted as noise, that is, that the signal-to-noise ratio is overrated and thus that the transmission rate is underrated.

Estimation of introduced frequency offset by a signal correction and transmission medium


Disclosed herein is a single screw gas compressor having a housing including a cylindrical bore, a primary and secondary gate rotors mounted for rotation in the housing, each gate rotor having a plurality of gear teeth, a main rotor rotatably mounted in the bore and having a plurality of grooves and a plurality of threads, wherein each groove meshingly engages at least one of the gear teeth from each gate rotor, a primary economizer port in communication with the cylindrical bore, and a secondary economizer port in communication with the cylindrical bore.

Compressors are used in various compression systems (e.g., refrigeration systems) to compress gas, such as freon, ammonia, natural gas, or the like, which is used to provide cooling capacity. One type of compressor is a single screw gas compressor, which is comprised of three basic components that rotate and complete the work of the compression process. These components include a single cylindrical main screw rotor with helical grooves, and two gate rotors (also known as star or star-shaped rotors), each gate rotor having a plurality of teeth. The rotational axes of the gate rotors are parallel to each other and mutually perpendicular to the axis of the main screw rotor. This type of compressor employs a housing in which the helical grooves of the main rotor mesh with the teeth of the gate rotors on opposite sides of the main rotor to define gas compression chambers. The housing is provided with two gas suction ports (one near each gate rotor) for inputting the gas and two gas discharge ports (one near each gate rotor) for entry and exit of the gas to the gas compression chambers. It is known to provide two dual slide valve assemblies on the housing (one assembly near each gate rotor) with each slide valve assembly comprising a suction valve (also referred to as a "capacity slide valve") and a discharge slide valve (also referred to as a "volume slide valve") for controlling an associated intake channel and an associated discharge channel, respectively. An electric motor imparts rotary motion through a driveshaft to the compressor's main rotor, which in turn rotates the two intermeshed gate rotors, compressing gas in the gas compression chambers. The compressed gas is passed to a condenser which converts the gas into a liquid. The liquid is further passed to an evaporator that converts the liquid into a gas again while providing cooling in the process.
To increase efficiency of a single screw compressor, an economizer, which is common in the industry, may be provided. The economizer function for screw compressors provides an increase in system capacity and efficiency by sub-cooling the liquid from the condenser through a heat exchanger or flash tank before it enters into the evaporator. More particularly, sub-cooling for the liquid is provided by sending high pressure liquid from the condenser into an economizer vessel through an expansion device to an intermediate pressure. The intermediate pressure in the economizer vessel is provided by an economizer port located part way in the compression cycle process of the screw compressor.
When the compressor unloads below about 60% of the full load capacity, the side/economizer port will drop in pressure level, ultimately being fully open to suction. Therefore, the liquid pressure decreases eventually down to suction pressure and no pressure difference will exist to push the liquid from the economizer vessel to the evaporator. Another side effect when the economizer port is fully opened to suction is the suction pressure will rise and the load on the compressor will need to be increased to keep the suction pressure constant.
One known method to maintain a constant economizer side port pressure is to keep the capacity slide position at 100% and run the compressor with a variable frequency drive (VFD), which can be used to unload the compressor by reducing the speed of the compressor instead of utilizing the capacity slide. Although this serves to maintain the desired pressure ratio at the economizer port, various drawbacks arise. For example, the added expense of purchasing the VFD and maintaining it is undesirable. In addition, the need for increased horsepower due to the inherent losses of the VFD can further increase cost by necessitating a larger capacity compressor. Further, the overall efficiency drops at lower speed due to the losses of the sealing effect between the internal bore and the threads of the rotor, which would allow additional gas to bypass from the high pressure side to the suction side of the compressor, and therefore increase operating costs.
Accordingly, it would be desirable to provide a method and apparatus for enhancing compressor efficiency that overcomes one or more of the aforementioned drawbacks.

Apparatus and method for enhancing compressor efficiency