Disclosed herein is an optical pickup device. In an embodiment of the present invention, sub beams from which an AC component has been removed are generated using a first diffractive element based upon properties that a beam incident on a disc is reflected with being separated by the track structure of the disc, and beams reflected from adjacent layers are prevented from being diffracted to sub cells for receiving the sub beams using a second diffractive element. In this case, the grating direction of the first diffractive element and the second diffractive element is adjusted, and thus the influence of dead zones generated in a tracking error signal due to the second diffractive element is removed.

1. Field of the Invention
The present invention relates, in general, to an optical pickup device and, more particularly, to an optical pickup device, which can prevent noise, generated from other layers, from flowing into servo signals.
2. Description of the Related Art
Ever since a Compact Disc (CD), which is an optical storage medium capable of storing up to 74 minutes of audio (music) or 650 Mbytes of data has been marketed, a Digital Versatile Disc (DVD) capable of holding two hours of Standard Definition (SD)-level video has been widely commercialized. Further, a Blu-ray Disc (BD) or a High-Definition (HD) DVD, capable of storing HD-level movie, will be introduced to the market in the near future.
Optical storage media, such as a CD, a DVD, and a BD, are disc-type media in which data is stored using optical characteristics, and data is recorded on an optical disc or the data recorded on the disc is reproduced through an optical pickup device. Optical storage media include discs for reproduction, on which data was previously recorded, and discs for recording which enable writing or rewriting, such as a CD-Recordable/Rewritable(R/RW), DVD-R/+R/-RW/+RW/Random Access Memory (RAM), a BD-Recordable/Recordable-Rewritable (-R/-RE).
An optical pickup records data on a disc or reads data from the optical disc in a state in which a laser beam is accurately focused on the track of the disc, which is rotating at high speed.
In order to obtain servo signals, such as a focusing error signal and a tracking error signal, corresponding to the position error of a beam spot focused on a disc, and to correct the position error of the beam spot on the basis of the servo signals, that is, in order to perform a servo operation, an optical pickup is implemented such that optical parts, such as an objective lens and a beam splitter, mechanical parts, such as an actuator and a base, and electrical parts, such as a laser diode and a photodetector, are arranged therein.
An astigmatic method is generally used for the detection of a focusing error signal, regardless of the type of disc and discs for recording/reproduction. In relation to the detection of a tracking error signal, a 3-beam method or a Differential Phase Detection (DPD) method is used in a disc for reproduction, and a Differential Push-Pull (DPP) method is representatively used in a disc for recording.
FIG. 1 illustrates the principles of the detection of a tracking error signal based on a DPP method.
The DPP method is a method which improves on a conventional 1-beam push-pull method and which can cancel offset occurring due to the movement of an objective lens in a radial direction or due to the tilt of a disc, and can detect a stable tracking error signal.
In the DPP method, a laser beam emitted from a light source is separated into three beams, that is, a 0th order diffracted beam and +/−1st order diffracted beams through a diffractive element called a grating. The grating is controlled such that, when a main beam, the 0th order diffracted beam, is arranged in the groove of a disc track, sub-beams, the +/−1st order diffracted beams, are arranged in lands adjacent to the groove in which the main beam is arranged (that is, such that the sub-beams are arranged to be spaced apart from the main beam by a distance of a ½ track pitch). Further, a tracking error signal is detected on the basis of differential signals of left and right signals of respective beams in a radial direction.
The main beam, reflected from the disc, is received by a 4-divided (a, b, c, d) main photodetector, and is detected as a Main Push-Pull (MPP)((A+D)−(B+C)) signal, which is a push-pull signal. Respective sub beams reflected from the disc are received by 2-divided (E1, E2) (F1, F2) sub photodetectors, and are detected as a Sub Push-Pull (SPP) ((E1−E2)+(F1−F2)) signal. When the sub beams are arranged to be spaced apart from the main beam by a distance of ½ track pitch, the phases of the MPP and SPP become opposite each other, as shown in FIG. 2.
Since offset occurs in the same direction both for MPP and SPP, according to the tilt or movement of an objective lens in a radial direction, an offset-free push-pull signal can be obtained if operation is performed using DPP=MPP−k×SPP (where k is a proportional constant). Further, a push-pull signal having greater amplitude can be obtained by subtracting the SPP having an opposite phase from the MPP.
Generally, the ratio of quantities of light of a main beam, used to generate an MPP signal, and sub beams, used to generate an SPP signal in the DPP method, is set to about 1:5:1 to 1:20:1, so that the light quantity of the sub beams is set to be equal to about ⅕ to 1/20 of that of the main beam. In the equation for obtaining the DPP signal, the proportional constant k is adjusted (for example, k is adjusted to 5 when the ratio of light quantities is 1:10:1), thus canceling the offset.
As described above, in order to use the DPP method, the angle of the sub beams, which are +/−1st order diffracted beams, must be adjusted while a grating is rotated. In this case, there is a disadvantage in that signal characteristics may be influenced by the extent of adjustment.
That is, when the main beam is positioned in a groove (or land), the sub beams must be positioned in the lands (or grooves). However, track pitches may differ from each other for respective disc types. For example, in the case of a DVD+RW or DVD-RW, the track pitch (Tp), indicating the distance between tracks, is 0.74 μm, and in the case of DVD-RAM, the track pitch is 0.615 μm, so that it is difficult to apply the same angle to discs having different track pitches.
Further, with the development of a BD or HD-DVD, the necessity for an optical disc recording/reproducing device capable of reproducing or recording all types of CD, DVD, and BD (or HD-DVD) has increased. However, since the numerical apertures of objective lenses required for the recording/reproduction of CD, DVD, and BD differ greatly from each other, it is almost impossible to reproduce all three types of discs using only a single objective lens.
In consideration of this necessity, an optical pickup, in which two objective lenses, that is, an objective lens for CD/DVD and an objective lens for BD or HD-DVD, are mounted on an actuator, has recently been developed. The two objective lenses can be arranged in the direction of the track (tangential direction) of a disc, or the inner/outer circumferential direction (radial direction) of the disc. When the objective lenses are arranged in the radial direction, it is not easy to access the innermost circumference of the disc, and thus an optical pickup in which two objective lenses are arranged in the track direction has been developed.
FIG. 3 illustrates an example in which one objective lens deviates from the central axis of a disc and is arranged off-axis when two objective lenses, mounted on a single actuator, are arranged in the track direction.
As shown in FIG. 3, when two objective lenses are arranged in the track direction, at least one of the two objective lenses deviates from the axis for connecting the inner and outer circumferences of a disc (axis passing through the center of the disc). In an optical system using the objective lens disposed at the location deviating from the central axis of the disc, since the relative positions of a main beam and sub beams required for DPP detection on the track (angle of the sub beams) vary as the optical pickup moves from the inner circumference of the disc to the outer circumference, the adjustment of the angle of the sub beams is meaningless.
Meanwhile, a multi-layer structure, in which two or more recording layers are formed to increase storage capacity, is being adopted in standards for DVD and BD. Further, it is expected that, even in the case of a high density disc, which will be developed in the future, a multi-layer structure will be generalized.
In order to increase the density of a disc, the wavelength of a laser beam is shortened, and the Numerical Aperture (NA) of an objective lens is gradually increased. In the case of a CD, a laser diode having a wavelength of 780 nm and an objective lens having an NA=0.45 are used. In the case of a DVD, a laser diode having a wavelength of 650 nm and an objective lens having an NA=0.6 are used. In the case of a BD, a laser diode having a wavelength of 405 nm and an objective lens having an NA=0.85 are used.
In a multi-layer disc, the interval between recording layers is determined to be approximately proportional to the focal depth of a beam spot. Since the focal depth is proportional to the wavelength of a laser beam and is inversely proportional to the square of the NA of an objective lens, the interval between recording layers must decrease as recording density increases.
When a recording or reproduction operation is performed on a multi-layer disc having a short interval between layers, a beam reflected from a layer adjacent to a current recording layer, that is, noise light from another layer, easily flows into photodetectors, as shown in FIG. 4.
Noise light from another layer also flows into a main photodetector for receiving a main beam and sub photodetectors for receiving sub beams, and thus influences servo signals as well as reproduced signals. In particular, the servo signals obtained using sub beams having a relatively small quantity of light are greatly influenced.
As shown in FIGS. 5A and 5B, there occurs a problem in that an SPP signal is excessively distorted due to noise light from another layer, and a DPP signal calculated based on the SPP signal, that is, a tracking error signal, is degraded. That is, when a disc having two or more recording layers is reproduced or recorded, noise occurs in reproduced signals and servo signals due to the beam reflected from another layer, as shown in FIGS. 4 and 5, and thus reproduction or recording performance may be deteriorated by this noise, and recording may occasionally be impossible.


A memory cell configuration has memory cells, each with a trench capacitor in a trench and a vertical transistor, which is used as a selection transistor. The trench capacitors in adjacent memory cells are arranged next to a bit line and are connected to the bit line via their selection transistor. Adjacent trench capacitors connected to a bit line are arranged alternately on the two sides of the bit line.

The present invention relates to a memory cell configuration.
Memory components, such as DRAMs (Dynamic Random Access Memories) comprise a cell array and a peripheral driver area. Individual memory cells are arranged in the cell array.
A DRAM chip contains a matrix of memory cells which are arranged in the form of rows and columns and are driven via word lines and bit lines. Data are read from the memory cells or data are written to the memory cells by virtue of suitable word lines and bit lines being activated.
Normally, a DRAM memory cell contains a transistor connected to a capacitor. The transistor comprises, among other things, two diffusion regions which are isolated from one another by a channel which is controlled by a gate. Depending on the direction of the flow of current, one diffusion region is called the drain region and the other diffusion region is called the source region.
One of the diffusion regions is connected to a bit line, the other diffusion region is connected to the capacitor, and the gate is connected to a word line. By applying suitable voltages to the gate, the transistor is controlled such that a flow of current between the diffusion regions through the channel is turned on and off.
The progressive miniaturization of memory components is increasing integration density in stages. The increase in integration density means that the surface area available per memory cell is constantly falling.
To utilize the available surface area effectively, the selection transistor may be in the form of a vertical transistor in a trench above a trench capacitor. Memory cells having a trench capacitor and a vertical transistor are described in U.S. Pat. No. 5,208,657, for example. Conventionally, the trench capacitors are arranged in a rectangular pattern in that case. A problem with this is that the alignment accuracy of successive photolithographic exposure planes can have a disadvantageous effect on the operability of the memory cells.
The object of the present invention is to provide a memory cell configuration which overcomes the above-noted deficiencies and disadvantages of the prior art devices and methods of this general kind, and which provides for improved alignment tolerance for successive photolithographic exposure planes.
With the above and other objects in view there is provided, in accordance with the invention, a memory cell configuration, comprising:
a substrate having a substrate surface;
a first memory cell with a first trench capacitor and a first transistor disposed in the substrate, the first transistor having a first gate connect;
a second memory cell with a second trench capacitor and a second transistor disposed in the substrate, the second transistor having a second gate connect;
a first word line connected to the first gate connect of the first transistor;
a second word line running adjacent to the first word line and connected to the second gate connect of the second transistor;
a bit line crossing the first word line and the second word line and dividing the substrate surface into a first area and a second area;
wherein the first memory cell and the second memory cell are connected to the bit line, and a larger part of the first trench capacitor is disposed in the first area and a larger part of the second trench capacitor is disposed in the second area.
A primary advantage of the novel configuration is the alternate arrangement of the trench capacitors with respect to the bit line. Normally, directly adjacent trench capacitors connected to a bit line have been arranged in a row below or on one side of the bit line. This meant that the minimum distance between two adjacent trench capacitors was relatively short. With the inventive arrangement, the distance between adjacent trench capacitors is significantly increased, so that the trench capacitors in the inventive arrangement can firstly be designed to have a larger diameter, which means that their capacitance is increased, and secondly have a much improved alignment tolerance with respect to the word lines and the bit lines.
In accordance with an added feature of the invention, the bit line encloses an angle with the first word line of between 45xc2x0 and 90xc2x0, i.e., the bit line crosses the first word line at an angle of 45-90xc2x0. This arrangement permits a compact layout for the cell array with optimum utilization of space on the substrate surface.
In accordance with an additional feature of the invention, the bit line changes a direction of its course upon crossing a respective word line. This permits the distance between bit line and trench capacitor to be set such that the bit line contact can be designed to have a high degree of alignment tolerance.
In accordance with another feature of the invention, the first trench capacitor has six nearest adjacent trench capacitors, spaced respective distances from the first trench capacitor differing by at most 15%. In other words, the first trench capacitor has six adjacent trench capacitors whose distances from the first trench capacitor differ by at most 15%. This arrangement sets the distance between the adjacent trench capacitors such that the substrate surface has the greatest possible density of trench capacitors which are each at the greatest possible distance from their nearest adjacent trench capacitors and therefore influence one another as little as possible.
In accordance with a further feature of the invention, the first trench capacitor and further trench capacitors are arranged in corners of a hexagon. It is advantageous if, in addition to the first trench capacitor, further trench capacitors are arranged in the corners of a hexagon. The hexagonal arrangement is the densest packing in the plane, so that this arrangement permits efficient utilization of the substrate surface.
In accordance with a concomitant feature of the invention, the first trench capacitor is disposed in a bottom area of a trench formed in the substrate, and the first transistor is a vertical transistor formed above the trench capacitor in the trench. This permits very great use to be made of the available substrate surface by the trench capacitors, and the selection transistors are arranged in a space-saving manner in the upper area of the trench.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a memory cell configuration, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.


Device for maneuvering and propulsion of a cleaning apparatus for removal of marine fouling from marine installations below surface. The device at least includes an induction part adapted to supply a fluid at high pressure, a nozzle with an inlet for supply of the fluid at high pressure, and a tubular body with an induction side and an outlet where said nozzle is arranged close to the induction side. The device also includes a system for cleaning of marine installations where one or more devices for maneuvering and propulsion are used.

Marine fouling is a problem within all marine activities such as shipping, within the fish farming industry and within the offshore petroleum industry. Within the shipping industry it is a problem with increased friction which increases the fuel consumption and thereby also increases among other the CO2 emissions. Traditionally toxic ship-bottom paints with zinc and lead compounds which have a harmful effect on organisms in the sea. Within the fish farming industry fouling prohibits flow through of water and thereby also reduces the level of oxygen in the seines. On fixed facilities and on oil facilities fouling can obscure constructional weaknesses and fouling may also accelerate fatigue of facilities such as quays, bridge pedestals and the like.
Pens have traditionally been cleaned by divers which have utilized high pressure water jets for removal of unwanted fouling. Vessels and fixed constructions have also to some extent been cleaned by divers with movable equipment for high pressure washing.
A disadvantage with manual removal is the process is slow, and if a routinely cleaning is requested as it is within the fish farming industry this solution becomes both bothersome and resource-demanding. As a consequence of the shortcomings due to these methods for cleaning more sophisticated and automated equipment for removal of marine fouling have been developed.
An example of a device for cleaning of marine installations is disclosed in Ser. No. 19/986,219 (Andorsen); this device comprises a plate like device with a plurality of rotors which is propelled by high pressure water. The device is guided alongside the objects to be cleaned with supplied high pressure so as to propel the rotors. Under optimal flow conditions this solution works out well.
It is a problem with the "rotor-device" for cleaning of marine installations that under not so optimal flow conditions the "rotor-device" is difficult to maneuver additionally it will often be difficult to follow the surface contour of the body to be cleaned. It shall be noted that the outer walls of the pens—fishing nets—not necessarily hangs straight down so that the fishing nets walls are vertical or follows a parable to its bottom, it is rather common that the pens fishing nets caused by flow conditions follows an s-shape towards its bottom. A number of other installations also have such a shaping that utilization of the rotor-device according to Ser. No. 19/986,219 will not render the requested maneuverability.

Device and system for manoeuvring cleaning apparatuses


A method for operating an exhaust-gas aftertreatment system arrangement is provided. The method includes in a first operating state, flowing a substantial majority of an exhaust-gas stream from the internal combustion engine through a first NOx storage catalytic converter positioned in a main exhaust branch of an exhaust aftertreatment system arrangement and in a second operating state, flowing a substantial majority of the exhaust-gas stream through a first bypass branch branching off from the main exhaust branch upstream of the first NOx storage catalytic converter and which opens into the main exhaust branch downstream of the first NOx storage catalytic converter and regenerating the first NOx storage catalytic converter.

Internal combustion engines may generate considerable amounts of nitrogen oxides (NOx) during operation. In the case of diesel and gasoline lean-burn engines used in motor vehicles, the amounts of nitrogen oxide in the exhaust gas are generally higher than the admissible limit values, such that exhaust-gas aftertreatment is desired in order to reduce the NOx emissions. In one prior art method, an SCR (Selective Catalytic Reduction) catalytic converter is used for reducing the NOx emissions. For the conversion of the nitrogen oxides by an SCR catalytic converter into non-hazardous substances, a supply of ammonia (NH3) may be needed, for example by way of an injection of a urea solution into the exhaust-gas stream. In another widely used method, use is made of a NOx storage catalytic converter (Lean NOx Trap, LNT) which absorbs and stores the nitrogen oxides contained in the exhaust gas of the internal combustion engine. A regeneration of the NOx storage catalytic converter must be performed from time to time, for which purpose it is necessary for an excess of fuel to be generated in the exhaust gas that is conducted through the NOx storage catalytic converter, which entails an additional consumption of fuel. Thus, both for the operation of an SCR catalytic converter and also of a NOx storage catalytic converter, additional costs are incurred owing to the needed provision of ammonia and of additional fuel.
U.S. Pat. No. 7,472,545 B2 for discloses an exhaust-gas aftertreatment system of an internal combustion engine including a NOx storage catalytic converter which is followed by an SCR catalytic converter. If fuel reformate is supplied to the NOx storage catalytic converter for regeneration purposes, the exhaust-gas stream is conducted past the NOx storage catalytic converter, via a bypass branch that is connected in parallel with respect to the latter, directly to the SCR catalytic converter. However, the inventors have recognized several drawbacks with the exhaust gas aftertreatment system disclosed in U.S. Pat. No. 7,472,545. For instance, during regeneration of the NOx storage catalytic converter engine emissions are increased. Moreover, regeneration of the NOx storage catalytic converter engine may only be implemented during engine operating conditions when the engine is operating at a desirable speed and/or load, thereby limiting regeneration of the NOx storage catalytic converter
As such in one approach, a method for operating an exhaust-gas aftertreatment system arrangement is provided. The method includes in a first operating state, flowing a majority of an exhaust-gas stream from the internal combustion engine through a first NOx storage catalytic converter positioned in a main exhaust branch of an exhaust aftertreatment system arrangement and in a second operating state, flowing a majority of the exhaust-gas stream through a first bypass branch branching off from the main exhaust branch upstream of the first NOx storage catalytic converter and which opens into the main exhaust branch downstream of the first NOx storage catalytic converter and upstream of a second NOx storage catalytic converter and regenerating the first NOx storage catalytic converter.
In this way, the first NOx storage catalytic converter may be regenerated while exhaust gas is directed around the NOx storage catalytic converter and then flowed into the second NOx storage catalytic converter, to reduce emissions during regeneration of the first NOx storage catalytic converter. Therefore, the first NOx storage catalytic converter may be regenerated independently of the engine speed or engine load, if desired. As a result, the NOx storage catalytic converter can be regenerated over a wider time frame of engine operation when compared with prior exhaust systems.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. Additionally, the above issues have been recognized by the inventors herein, and are not admitted to be known.

Arrangement for exhaust-gas aftertreatment system for an internal combustion engine and method for operating the exhaust-gas aftertreatment system arrangement


A thrust washer formed from metal sheet has a flat, ring-shaped thrust portion oriented radially, an axially oriented circumferential lip extending along one of the inner and the outer diameters of the thrust portion, and a tab extending from the circumferential lip. The tab includes a radially oriented mid-portion and at least one wing-portion extending perpendicular to the mid-portion and parallel to the axis of the thrust portion such that a flat surface of the wing-portion may engage a recess of a backup member to prevent rotation of the thrust washer relative to the backup member.

This invention relates generally to thrust bearings and, more particularly, to a lipped thrust washer having an anti-rotation feature.
Thrust bearings with rollers are intended to transmit thrust through the rollers, rolling on raceways of two opposed thrust washers, without sliding of the thrust washers along their respective backup surfaces. Such sliding may be a problem, particularly when a backup surface is made of a material that is softer than the preferred hardened steel, such as unhardened steel, aluminum or even plastic, for example. In such applications, a simple tab extending radially outwardly from the thrust washer would cut into the backup material rather than prevent relative rotation. Accordingly, there is a need for a thrust washer with an anti-rotation device suitable for relatively soft backup materials.
The foregoing illustrates limitations known to exist in present devices and methods. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.

Axially oriented anti-rotation feature for lipped thrust races


Devices and methods are provided to conduct fluid away from or deliver fluid to an area of a treatment site of a patient's body. In one aspect of the invention, a catheter includes a terminal end with a fluid exchange portion. The terminal end may further include a diffuser. The terminal end may further include a barrier.

Many medical procedures benefit from transporting fluid to or from a treatment site of a patient's body. Devices for transporting fluid in a medical procedure are generally referred to as catheters. They may be used to provide drainage or administer treatment fluids. For example, catheters may be used to drain fluids from organs or from areas of abnormal fluid collection such as in a surgical wound following a surgical procedure. Catheters may also be used to deliver fluid to a treatment site to provide a vast range of therapies from cancer treatment to nutritional supplementation. A few exemplary therapies include stimulating tissue growth, administering antibiotics, flushing away impurities, killing or halting the reproduction of cancer cells, and relieving pain.
Catheters may be used in gravity driven arrangements such as with a collection container located below the treatment site or a medication container located above the treatment site. Likewise, catheters may be used in pressurized arrangements. For example, suction may be applied to a drainage catheter to draw fluids away from the treatment site. Suction devices may include elastomeric bulbs, spring actuated bellows, electromechanical vacuum pumps, and other known medical suction devices. Pressurized fluid may also be delivered through a catheter to the treatment site. For example, fluid infusion devices may include manual syringes, elastomeric infusion devices, spring loaded infusion devices, electromechanical infusion devices, and other known infusion devices.
Typical prior catheters are linear devices having one or more openings formed along a portion of their length through which fluid passes. They often perform poorly due to an inability to drain fluids from or deliver fluids to a sufficiently large area to encompass the entire treatment site. In addition, tissue folds and tissue apposition further affect the movement and collection of fluid making it difficult for prior catheters to adequately address the treatment site.
For example, where a treatment site encompasses a two or three dimensional treatment area, prior drainage catheters are only able to drain fluid from a relatively small, linear portion of the treatment area often leaving behind pockets of fluid.
Similarly, prior infusion catheters only deliver treatment fluid to a relatively small, linear portion of the treatment site leaving much of the site untreated. Prior infusion catheters may also deliver too much treatment fluid to a relatively small area resulting in pooling of treatment fluid or contact with non-target tissues. For example, infusion catheters may be used to deliver pain relieving medication directly to a surgical site to provide, for example, post-operative relief of pain resulting from a surgical intervention. If, for example, the medication does not reach tissue disrupted during the surgical intervention, it may not relieve the pain. Alternatively, if the anesthetic is delivered indiscriminately, undesired interactions may occur with local structures such as, for example, spinal nerves or vital organs.


A semiconductor memory device stably operates over a wide range of the power supply voltage by including a power supply voltage level detector for generating detecting signals according to predetermined levels of the power supply voltage and an oscillator for generating a frequency-controlled oscillation pulse whose frequency is changeable according to the detecting signals. Thus, a boosting ratio of a boosting circuit, the refresh period of a refresh circuit and the substrate voltage of a substrate voltage generator can be adaptively changeable according to the variation of the power supply voltage.

The present invention relates to a semiconductor memory device, and more particularly to a semiconductor memory device stably operating over a wide range of the power supply voltage.
Currently, operating voltages of semiconductor memory devices are being diversified and lowered. Using a low power supply voltage is generally advantageous in decreasing the power consumption, especially in a semiconductor memory device which employs a battery as a power supply. However, the low power supply voltage causes various problems. For example, the low power supply voltage may not be high enough to drive word lines. This is because, in order to fully turn on a cell transistor, the voltage for driving the word lines must be higher than the voltage for driving the bit lines. Taken a DRAM cell as an example; when data "1" in the low power supply voltage level is stored in a storage capacitor via a bit line pair by turning on a cell transistor, it is preferable to boost the potential level of the data "1" up to the power supply voltage plus the threshold voltage of the cell transistor, prior to storing the data. To this end, a boost voltage is employed, which is obtained by boosting the power supply voltage up to a predetermined level, using a boosting circuit. Generally, a boosting ratio indicative of how many times the power supply voltage is boosted up from the power supply voltage, is fixed. Consequently, the boost voltage resulting from a overly-low power supply voltage is still too low to overcome the threshold voltage, thereby causing a malfunction during writing in and/or reading out the data. Contrarily, the boost voltage resulting from a overly-high power supply voltage becomes excessively high to thus destroy a gate layer of the cell transistor, thereby causing an inevitable damage to the memory device.
A technique is suggested for solving the foregoing problems in Symposium on VLSI Circuits, 1990, by Nakagome et al. in an article entitled: "A 1.5 V Circuit Technology for 64 Mb DRAMs". The article discloses that if a power supply voltage in a range of 1.5 V-3.3 V is applied to the semiconductor memory device, the power supply voltage is converted into 1.5 V to drive the memory device. Accordingly, the memory device can be operated by the power supply voltage of a wide voltage range, e.g., 1.5 V-3.3 V. In addition, since the power supply voltage is lowered to a voltage of 1.5 V in the memory device to be used as an operating voltage, the power consumption is reduced. In this technique, to drive the word lines, the voltage of 1.5 V is boosted up to a predetermined level by a boosting circuit (refer to 1990 Symposium on VLSI Circuits Digest of Technical Papers, pp. 17-18, for more detailed technical information).
However, since the relatively low voltage of 1.5 V is used in the above described conventional technique, the boosting ratio should be high enough to obtain a sufficiently boosted voltage for driving the word lines. Consequently, the boosting circuit should operate very frequently to boost up the power supply voltage, which causes an increase of the power consumption.
Furthermore, since a sufficiently high power supply voltage is forcibly dropped down to be used as an operating voltage of 1.5 V, the power is unnecessarily consumed. Also, with using pump capacitors, to boost up the voltage which has been forcibly dropped down to 1.5 V is very inefficient, and brings on a power loss caused by operations of the boosting circuit.


Document processing and understanding can be important for a variety of applications such as office automation, creation of electronic manuals, online documentation and annotation, etc. The first step towards this process can involve the decomposition of a page into separate units describing the text, graphics, pictures etc. Towards that end, a method of page decomposition comprises segmenting an image into a plurality of blocks according to an amount of information contained in each block, classifying each block according to a corresponding frequency spectrum, and refining a classification of each block.

1. Field of the Invention
The present invention relates to page decomposition and more particularly to a method of page decomposition using local orthogonal transforms and a map optimization.
2. Discussion of Related Art
Despite the emergence of electronic documents there has not been a significant decrease in the use of paper based documents. In fact, The use of paper documents may have increased due to a preference for paper documents for reading and archiving purposes. Similarly, newspapers continue to be popular even after the introduction of the radio, TV and World Wide Web. However, storing and analyzing paper documents and more importantly, retrieving them can be a cumbersome task. Electronic documents however, have the advantage that they can be manipulated and analyzed easily. Consequently, transformation of a paper document to an electronic form has become an important task.
The understanding and transformation of paper documents is nontrivial. It has been observed that the development of a general system that can process all kinds of documents such as technical reports, engineering drawings, books, journals, newspapers etc. can be far more complex. For coding and understanding a range of documents, an application needs to identify text, image and graphics regions as physical segments of the page to be able to process them properly.
The majority of page segmentation works are, to an extent, dependent on page layout and can be classified as either bottom-up or top-down. Bottom-up approaches often use connected component grouping where one starts from the pixel level and, in an hierarchical fashion, combines pixels into larger and larger entities such as characters, lines, text, graphics etc. In the top-down strategy, an image is broken into blocks that can be identified and further subdivided appropriately. There are also hybrid methods that combine the top-down and the bottom-up approaches. In other approaches, after detecting major blocks, simple statistical tests classify them as either text or non-text regions. Black pixel density, black/white ratio, transitions, average vertical or horizontal run-lengths are some of the features that these methods take into account during post classification stages. Yet another method analyses the background white space. In this scheme, major white spaces between printed components are tracked to identify boundaries. This method is based on a few assumptions and provides good results even for skewed images or documents with complex layouts. However, it can only be applied for images that are clean and where there is no overlap between regions.
In contrast to the geometric layout analysis, the logical layout analysis has not received as much attention. Some logical analysis performs region identification or classification in a derived geometric layout. These approaches are however, primarily rule based and thus the final outcome depends on the dependability of the prior information and how well that is represented within the rules.
Therefore, a need exists for a method of page decomposition using local orthogonal transforms and a map optimization.

Page decomposition using local orthogonal transforms and a map optimization


A magnet for magnetic resonance imaging has an interior working space within the magnet frame sufficient to accommodate a physician and a patient. Because the physician is positioned inside the magnet frame, the physician has unimpeded access to the patient. Elements of the magnet frame desirably encompass a room, and the magnet frame may be concealed from view of a patient within the room. Preferred embodiments facilitate MRI imaged guided surgery and other procedures performed while the patient is being imaged, and minimize claustrophobia experienced by the patient. Also provided is a magnet having field coils disposed about the of pole portions of the magnet. A diagnostic facility for high volume MRI use is also disclosed.

The present invention relates to magnetic resonance imaging or xe2x80x9cMRIxe2x80x9d.
MRI is widely used in medical and other arts to obtain images of a subject such as a medical patient. The patient""s body is placed within a subject-receiving space of a primary field magnet and exposed to a strong, substantially constant primary magnetic field. The atomic nuclei spin around axes aligned with the magnetic field. Powerful radio frequency xe2x80x9cRFxe2x80x9d signals are broadcast into the subject-receiving space to excite atomic nuclei within the patient""s body into a resonance state in which the spinning nuclei generate minuscule RF signals. These signals are referred to herein as magnetic resonance signals. Magnetic field gradients are applied so that the magnitude of the magnetic field varies with location inside the subject-receiving space. As a result, characteristics of the magnetic resonance signals from different locations within the region, such as the frequency and phase of the signals, can be made to vary in a predictable manner, depending upon position within the region. Thus, the magnetic resonance signals are xe2x80x9cspatially encodedxe2x80x9d so that it is possible to distinguish between signals from different parts of the region. After repeating this procedure with various different gradients, it is possible to derive a map showing the intensity or other characteristics of the magnetic resonance signals versus position within the excited region. Because these characteristics vary with concentration of different chemical substances and other characteristics of the tissue within the subject""s body, different tissues provide different magnetic resonance signal characteristics. When the map of the magnetic resonance signal characteristics is displayed in a visual format, such as on screen or on a printed image, the map forms a visible picture of structures within the patient""s body.
MRI provides unique imaging capabilities which are not attainable from any other imaging method. For example, MRI can provide vivid, detailed images of soft tissues, including abnormalities such as tumors, and other structures which cannot be seen readily in X-ray images. Moreover, MRI operates without exposing the patient or the physician to ionizing radiation such as X-rays. For these and other reasons, MRI is widely utilized in medicine.
Some of the primary field magnets utilized heretofore have imposed severe physical constraints on the patient and on medical personnel attending to the patient during the MRI procedure. For example, conventional solenoidal primary field magnets use a series of circular superconducting coils spaced apart from one another along an axis. These magnets provide a small, tubular subject-receiving space enclosed within the solenoids. A patient to be imaged must slide into the tubular space. The experience may be highly claustrophobic. Some obese or pregnant patients often cannot fit inside the patient-receiving space. Moreover, it is essentially impossible for a physician or technician to reach those regions of the patient disposed inside the subject-receiving space.
Attempts have been made heretofore to create xe2x80x9copenxe2x80x9d MRI primary field magnets using ferromagnetic frames. Although these designs provide somewhat better access to the patient for certain diagnostic scanning, and a somewhat less claustrophobic experience for the patient, they are less than optimal for surgical intervention or physician/technician-assisted diagnostic procedures. For example, these designs provide limited access of physicians, surgeons, or technicians, to the patient. Additionally, the designs have difficulty providing a highly uniform field with pole dimensions desirable for surgery or diagnostic purposes.
As described, for example, in commonly assigned U.S. Pat. No. 4,707,663, other primary field magnets utilize ferromagnetic frames to route and concentrate magnetic flux into the patient-receiving space. Primary field magnets using such a ferromagnetic frame can employ permanent magnets, resistive electromagnetic coils, or superconducting coils having a relatively low number of ampere-turns while still providing a high field strength in the patient-receiving space. Moreover, such magnet assemblies can provide excellent field uniformity. Ferromagnetic frame magnets in accordance with the ""663 patent also provide a less claustrophobic, more accessible subject-receiving space.
As disclosed in co-pending, commonly assigned U.S. patent application Ser. No. 07/952,810 filed Sep. 28, 1992, now U.S. Pat. No. 5,754,085 the disclosure of which is hereby incorporated by reference herein, a ferromagnetic magnetic frame may include a pair of plate-like pole supports spaced apart from one another and supported above one another by a set of columns. In preferred magnets according to the ""085 patent, the frame defines a polar axis passing through the space between the pole supports. Preferably, ferromagnetic poles project from the pole supports adjacent the polar axis, so that the poles define a subject-receiving space at a medial plane, midway between the plates. The columns have unique shapes such that, in preferred embodiments, the columns flare outwardly in the radial direction, away from the polar axis adjacent the medial plane. The dimensions of each column in the circumferential direction, around the polar axis desirably taper so that the circumferential dimension of each column is at a minimum in a region adjacent the medial plane. As described in further detail in the ""085 patent, magnets with ferromagnetic frames in accordance with preferred embodiments of the invention taught therein can provide a unique combination of accessibility and a large, aesthetically pleasing, and non-claustrophobic, patient-receiving space and can also provide high field strength without resort to superconducting coils. Even higher field strengths can be provided where superconducting coils are used.
Magnets according to preferred embodiments taught in the ""085 patent thus provide an elegant solution to the problems of claustrophobia, lack of access and limitations on field strength and uniformity posed by prior designs. Surgical operations and other medical procedures can be performed readily on a patient while the patient is disposed inside the patient-receiving space of preferred magnets according the ""085 patent. The ability to perform surgical operations while the patient is disposed inside the patient-receiving space allows the physician to treat the patient under direct guidance of a MRI image acquired during the procedure itself. For example, as the surgeon advances a probe into the body to treat a lesion, the surgeon can see the probe and the lesion in the MRI image.
However, even with this enhanced design, the patient still perceives the MRI procedure as involving placement of his or her body into the interior of a machine. Moreover, the physician treating the patient still perceives that he or she must stand outside of the apparatus and reach into the apparatus to gain access to the patient. Accordingly, even further improvement in primary field magnet structures for MRI apparatus would be desirable.
One aspect of the present invention provides a magnet for magnetic resonance imaging apparatus which includes a frame. The frame desirably incorporates a pair of opposed ferromagnetic pole supports spaced apart from one another and a pair of ferromagnetic poles connected to the pole support. The poles project from the pole supports toward one another along a polar axis. The poles have distal ends remote from the pole supports. The distal ends confront one another and are spaced apart from one another by a gap distance so as to define a subject-receiving gap between the poles. The frame further includes one or more connecting elements extending between the pole supports. The connecting elements are spaced apart from the poles in a direction or directions transverse to the polar axis. The magnet further includes a source of magnetic flux adapted to direct flux through the frame so that the flux passes between the distal ends of the poles through the gap and returns through the pole supports and the connecting elements.
Most preferably, the magnet defines a working space alongside of the poles, between the pole supports and between the poles and the connecting elements sufficient to accommodate one or more adult human attendants. Thus, an attendant can be positioned inside the working space, within the magnet itself and can have access to a patient disposed in the gap between the poles. The working space desirably is about six feet or more high and about two feet or more wide, so that the attendant can work in a standing position. Most preferably, the working space extends entirely around the poles, and is unobstructed by any feature of the magnet itself. The magnet desirably includes a plurality of enclosing structures including walls, a floor and a ceiling which cooperatively define a room. The poles extend into the room, but the remainder of the frame desirably is at or outside the exterior of the room. For example, where the pole supports are spaced vertically apart from one another and the polar axis extends vertically, the poles project into the room from the floor and ceiling. Thus, the patient experiences entry into the MRI magnet as entry into a normal room with some structures extending from the floor and ceiling. Stated another way, the elements such as the connecting elements and pole supports are so far away from the patient that they do not create any feeling of claustrophobia. Because the physician or other attendant is inside the room and inside the space enclosed by the pole supports and connecting elements, these elements do not impede access by the physician or other attendant to the patient at all.
The connecting elements may be in the form of plates constituting one or more walls of the room as well as providing the pole supports which may be formed as further plates constituting the floor and ceiling of the room. The enclosing structure may further include concealment structure which conceals those parts of the frame constituting the walls from view from within the room. For example, the interior surfaces of the plates may be covered with conventional wall, floor and ceiling coverings. This contributes to the patient""s belief that he or she is inside a normal room. According to further aspects of the invention, the concealment structure may include surface decoration on the surfaces bounding the room as, for example, on the walls, ceiling or floor. The magnet structure may also include pole covers covering the poles and associated structure, and the surface decoration may be provided on the pole covers as well. The surface decoration may define an outdoor scene, such as a landscape or seascape incorporating a sky region. This enhances the open, non-claustrophobic environment provided by the magnet.
Because the pole supports and connecting elements are disposed outside of the area occupied by the patient and attendant, these elements can be of essentially unlimited size. Essentially any amount of ferromagnetic material can be used to provide a low reluctance flux return path and to perform uniform distribution of flux passing to the poles. Magnets in accordance with preferred aspects of the present invention thus can provide a highly concentrated, strong magnetic field in the subject-receiving gap. Magnets according to this aspect of the invention can utilize permanent magnets, super-conducting coil or, resistive electromagnetic coils as the source of electromagnetic flux. In a particularly preferred arrangement, a coil such as a resistive electromagnetic coil encircles each pole. In systems intended to provide optimum access to the patient, for surgery or other procedures requiring considerable interaction with the patient, the coils may be disposed adjacent to the pole supports. In this configuration, the working space extends around the poles between the coils. Where the polar axis extends vertically, the working space desirably extends above one coil and below the other coil. For example, one coil may be disposed beneath the floor of the room whereas the other coil may be disposed above the ceiling.
Magnets according to a further aspect of the invention are arranged to provide optimum field uniformity. In magnets according to this aspect of the invention, the coils may extend in regions of the poles adjacent the pole tips. Thus, the coil associated with each pole may extend to within about 6 inches (15 cm) of the pole tip, and desirably to within about 3 inches (7.5 cm) of the pole tip. The coil associated with each pole may be provided as a relatively narrow toroidal solenoid in the vicinity of the pole tip or, preferably, as an elongated cylindrical solenoid surrounding the pole, the solenoid having a tip end in the vicinity of the pole tip and having a support end in the vicinity of the pole support. In these systems, the working space extends around the outside of the coil. To maintain good access to the patient, the coil desirably has a radial thickness of about 6 inches or less. Magnets according to this aspect of the invention are especially well suited to use in diagnostic procedures, including imaging without other intervention during imaging and also including interventional MRI procedures such as procedures involving the use of MRI contrast media or intrabody probes during imaging. The access to the patient provided by the magnets in accordance with this aspect of the invention also allow them to be used for surgery or other procedures requiring considerable interaction with the patient.
The gap distance between the distal ends of the pole preferably is about two feet or more. The distal ends of the poles may be either circular or non-circular. In systems intended to provide optimum access to the patient, and which employ poles with circular distal ends, the ratio between the diameter of each pole distal end and the gap distance between the poles is desirably about 2 to 1 or less. In systems designed for such optimum access where the distal ends of the poles are non-circular, the ratio between the longest dimension of each pole surface and the gap distance is desirably about 2 to 1 or less, and the ratio of the shortest dimension of each pole surface to the gap distance desirably is about 1.5:1 or less.
The magnet desirably incorporates features to further enhance field uniformity in the patient-receiving gap. Where coils are employed as the source of magnetic flux, each coil encircles the associated pole. Also, the magnet desirably includes shimming features such as shim rings, slots or other elements defining magnetic flux paths having different reluctances at different distances from the polar axis. To further promote field uniformity, each pole may include a pole tip defining a distal end of the pole and a pole stem extending from the proximal end of the pole to the pole tip. The flux source is arranged to direct the flux in a forward direction through each pole. The magnet may include stem bucking magnets surrounding the pole stem. The stem bucking magnets desirably provide flux directed in a reversed direction opposite to the forward direction. This tends to minimize leakage of flux from the pole stems to the connecting elements. The relatively large spacing between the poles and the connecting elements in radial directions transverse to the polar axis helps to minimize flux leakage from the poles, so that a very large portion of the flux tends to pass between the poles. This further promotes flux uniformity and a strong field in the subject-receiving gap.
In a particularly preferred arrangement, the vertical connecting elements are disposed at least about 7 feet from the polar axis. Thus, a typical human patient can be positioned with the long axis of his or her body extending in any desired radial direction and with any portion of his or her body at the polar axis. For example, if the patient""s head is positioned at the polar axis, as where procedures or imaging are to be performed on the head, the patient""s feet can point in any direction. In one arrangement, the connecting elements include a pair of connecting elements such as a pair of opposed, heavy, plate-like walls disposed at least about 14 feet apart from one another and defining two opposite ends of a room. In other embodiments, the polar axis may extend horizontally, and the pole supports may extend along walls of the room defined by the magnet frame.
In yet another aspect of the present invention, there is provided a diagnostic facility comprising a magnet, such as the magnets described above and magnetic resonance imaging apparatus utilizing the magnetic field applied by the magnet to provide an image of a patient received in the patient-receiving gap. Preferably, this facility includes one or more devices for performing or assisting in diagnostic procedures on a patient disposed in the patient-receiving gap. These devices are accessible within the working space. Preferably, the facility includes a staging area that includes a plurality of patient-carrying devices for carrying patients from the staging area to the patient-receiving gap and for supporting patients during diagnostic procedures. The patient-carrying devices may be pre-positioned and arranged within the staging area to provide for substantially continuous usage of the magnet for performing substantially continuous diagnostic procedures. Most preferably, one of the plurality of patient-carrying devices is positioned within the patient-receiving gap of the magnet, while one or more additional patient-carrying devices are outside of the patient-receiving gap. In a particularly preferred arrangement, the facility includes a plurality of preparation rooms and an infeed passageway communicating with the preparation rooms, so that patients can be positioned on the patient-carrying devices in the preparation rooms and can be carried on such devices through the infeed passageway into the patient-receiving gap of the magnet. Most preferably, the infeed passageway extends to the patient-receiving gap of the magnet from one side of the gap, and the facility includes an outfeed passageway extending from the other side of the patient-receiving gap. The outfeed passageway desirably leads back to the preparation rooms. In this arrangement, a succession of patients can be pre-positioned on the patient-carrying devices, and can be conveyed in sequence through the infeed passageway, into the magnet for imaging and then out of the magnet after imaging and back to the preparation rooms through the outfeed passageway.
A further aspect of the invention provides methods of magnetic resonance imaging wherein a succession of patients is conveyed into and out of a magnet in the manner discussed above, each patient being imaged while that patient is positioned in the patient-receiving gap of the magnet.
In yet another aspect of the present invention, there is provided a method of magnetic resonance for diagnostic purposes including the steps of positioning a patient within a gap defined by a frame of a magnet, positioning a technician within a working space within the frame of the magnet adjacent the gap, obtaining magnetic resonance data from the patient using a magnetic field applied by the magnet. Preferably, this method includes the step of having the technician in the working space assist the patient during one or more of the following phases of the procedure: positioning the patient within the gap; performance of diagnostic procedures while the patient is within the gap; and removal of the patient from the gap. The step of obtaining magnetic resonance data optionally may be performed so as to generate a magnetic resonance image of the patient.
A further aspect of the invention provides improved resistive coils for magnetic resonance imaging static field magnets. A coil according to this aspect of the invention includes a plurality of spiral windings extending around an axis. Each winding has an inner end adjacent the axis, an outer end remote from the axis and a conductor extending in multi-turn spiral between the inner end and the outer end. The windings include one or more outward windings and one or more inward windings. The turns of each outward winding are arranged such that a point moving along the turns in a first direction of rotation about the axis moves from the inner end towards the outer end. The turns of each inward winding are arranged so that a point moving along the turns in the first direction of rotation about the axis moves from the inner end towards the outer end. The windings are stacked one above the other along the axis and are electrically connected in series with one another. The electrical connections between the windings most preferably include one or more interior connections, the inner end of one of said inward windings being connected to the inner end of one of said outward windings at each such interior connection. The connections typically also include one or more exterior connections, the outer end of one of the outward windings being connected to the outer end of one of the inward windings at each such exterior connection. Most typically, the inward windings and the outward windings are arranged in alternating sequence along the axis. The interior connections and the exterior connections are also arranged in alternating sequence along said axis. As further discussed below, such a coil will provide essentially the same magnetic performance as a solenoid wound with an equal number of turns. However, the coil in accordance with this aspect of the invention can be fabricated more readily than a conventional helical coil having multiple helical layer nested within one another, particularly where the conductor is a relatively stiff element such as a metallic bar having cross-sectional dimensions of about 5 mm or more.
Preferably, the conductors of the windings are tubular so that each said winding has a bore extending through the conductor between its inner end and its outer end. The coil may further include a plurality of coolant ports communicating with the bores of the windings. The ports serve as coolant inlets and coolant outlets for passing coolant through said windings. The coolant ports desirably are arranged so that the bore of each winding is connected in a fluid flow path between a coolant inlet and a coolant outlet, but so that each fluid flow path extends through less than all of said windings. Thus, different windings are connected in different fluid flow paths. Each fluid flow path provides flow resistance far less than that which would be expected in a single flow path extending through the entire coil. This greatly facilitates coil cooling, and minimizes heat transfer to the pole and to other surrounding structures.
Further aspects of the invention include magnets for resonance imaging including a pair of coils as discussed above and a ferromagnetic frame including a pair of ferromagnetic poles projecting along a polar axis defining a patient-receiving gap therebetween, the poles having proximal ends remote from the gap and tips bounding the gap. The frame further includes a ferromagnetic flux return structure extending between poles.
Yet another aspect of the invention provides methods of fabricating a coil for a magnetic resonance imaging magnet. Methods according to this aspect of the invention desirably include the steps of a plurality of inward and outward spiral windings as discussed above, the windings being separate from one another; superposing the spiral windings one above the other so that said spiral windings are substantially coaxial with one another; and electrically connecting the windings in series with one another. The connecting step desirably includes the step of forming one or more interior connections and exterior connections as discussed above. Preferably, the conductors constituting the windings are tubular. The step of electrically connecting the windings in series with one another includes the step of joining the tubular windings to one another so as to form a continuous fluid path between windings at least some of said connections.
Yet another aspect of the invention provides a magnet for magnetic resonance imaging having a ferromagnetic frame defining a patient-receiving space and a source of magnetic flux in magnetic circuit with said frame so that flux produced by said source will pass through said patient-receiving space and through said frame; and means for suppressing temperature changes in the frame during operation. Most preferably, such means include thermal insulation covering at least a part of said frame. This aspect of the invention incorporates the realization that changes in the magnetic properties of the frame due to changes in temperature of the frame can cause changes in magnetic fields in the patient-receiving space. By suppressing these temperature-induced changes, the magnet according to this aspect of the invention provides enhanced field stability and uniformity.
These and other objects, features and advantages of the present invention will be more readily apparent from the detailed description of the preferred embodiments set forth below, taken in conjunction with the accompanying drawings.


A hydraulic block of a slip control system of a hydraulic vehicle brake system includes receptacles for the hydraulic accumulator and receptacles for outlet valves arranged on opposite sides of each other in the hydraulic block. The sides of the hydraulic block, which comprise the receptacles for the outlet valves and the hydraulic accumulators, are connected to one another by bores perpendicular thereto.

The core of such slip control systems is a hydraulic assembly, which has a hydraulic block which is equipped with hydraulic components of the slip control system and is connected to a master brake cylinder by brake lines and to which one or more hydraulic wheel brakes are connected by brake lines. Hydraulic components are, amongst other things, solenoid valves, hydraulic pumps (most commonly piston pumps), non-return valves, hydraulic accumulators, damper chambers and pressure sensors. The hydraulic block is typically a box-shaped metal block, which serves for the mechanical fastening and hydraulic wiring of the hydraulic components of the slip control system. Wiring means the hydraulic connection of the hydraulic components according to a hydraulic circuit diagram of the slip control system.
The hydraulic block has receptacles for the hydraulic components of the slip control system. This usually refers to cylindrical countersinks, blind or through holes, most commonly with a stepped diameter, which are incorporated in the hydraulic block and into which the hydraulic components are fully or partially introduced, for example pressed. For example, hydraulic pumps are usually fully introduced into their receptacles in a hydraulic block, whereas, in the case of solenoid valves, only a hydraulic part is usually introduced into a receptacle of a hydraulic block and an electromagnetic part of the solenoid valve protrudes from the hydraulic block. The receptacles are connected to one another according to the hydraulic circuit diagram of the slip control system by a normally Cartesian bore arrangement of the hydraulic block. Cartesian bored means that bores are incorporated in the hydraulic block such that they are parallel or at a right angle to one another and to surfaces and edges of the hydraulic block. Equipped with the hydraulic components, the hydraulic block forms a hydraulic assembly.
For connecting the hydraulic block to a master brake cylinder and for connecting hydraulic wheel brakes to the hydraulic block, known hydraulic blocks have connections for brake lines. The connections are typically cylindrical countersinks or blind holes which have, for example, an internal thread for screw connection to a screw nipple of a brake line or are threadless for pressing-in and caulking a press-in nipple of a brake line, preferably in a so-called self-clinch technique. Self-clinch means that, when pressed into the connection of the hydraulic block, the press-in nipple is caulked in the connection of the hydraulic block in a pressure-tight manner under plastic deformation of the material of the hydraulic block itself.
Published patent application DE 10 2006 059 924 A1 discloses a hydraulic block for a hydraulic assembly of a slip control system of a hydraulic vehicle brake system, in which all receptacles for solenoid valves of the slip control system are arranged in a cover side, which can also be referred to as the valve side, of a box-shaped hydraulic block. The cover side is one of the two large sides of the box-shaped hydraulic block, which is not cube-shaped but is longer and wider than it is thick. The cover side can be square or rectangular.
In the known hydraulic block, connections for brake lines which lead to hydraulic wheel brakes are incorporated in a transverse side, which can also be referred to as the connection side. The connection side adjoins the valve side. Receptacles for hydraulic accumulators are arranged in a transverse side of the known hydraulic block which is opposite the connection side and likewise adjoins the valve side.

Hydraulic block for a hydraulic assembly of a slip control system of a hydraulic vehicle brake system


An assembly and method for adapting a baby stroller to better travel over unstable ground, such as sand. A sledge is provided that has a top surface and a bottom surface. The bottom surface is flat with a beveled front end that enables the sledge to be easily pulled over sand or mud. Retention features, such as semi-cylindrical depressions, are formed in the top surface of the sledge. The retention features enable a baby stroller to be placed atop the sledge without rolling off. Once the wheels of the stroller are attached to the sledge, the sledge can be pulled through sand and mud more easily. The sledge may be supported by wide wheels to help the sledge roll over unstable ground. Furthermore, the sledge may be collapsible so that it can be easily stored when not in use.

1. Field of the Invention
The present invention relates to devices adapted to receive and carry wheeled carts along the sand on a beach. More particularly, the present invention relates to portable devices specifically designed to support baby strollers upon sand or other loose earth.
2. Prior Art Statement
When people travel to the beach, a lake, or other recreational location, they often take a large number of accessories intended to make the visit more pleasurable. For example, when people visit the beach, they often take folding chairs, umbrellas, coolers, buckets, shovels, blankets, fishing poles and bags filled with smaller items such as sunscreen and a change of clothing. In many instances, a person visiting the beach is unable to drive his/her vehicle directly onto the beach. Similarly, many people visiting the beach stay at hotels or homes that are not directly on the beach. As a consequence, people traveling to the beach are required to physically carry to the beach all the accessories they require. Often the number of accessories is too great for a single trip, so a person must make multiple trips to and from the beach in order to transport all the needed accessories. This problem is compounded for people who have small children. Small children require many extra accessories such as playpens, toys, diaper bags and swimming safety gear, all of which must also be carried to and from the beach. Furthermore, small children cannot be left on a beach unattended. Consequently, an adult working alone must carry the child with them each time they walk on and off the beach.
Transporting a small child back and forth would be greatly simplified if a baby stroller could be used. A baby stroller would hold the child and much of the equipment needed for the child. The only problem is that strollers do not roll on sand, mud, or loose gravel. Most baby strollers are designed with small narrow wheels. This enables the stroller to roll rapidly and turn quickly on hard, smooth surfaces. However, when a traditional stroller is pushed onto a beach or onto loose gravel, the narrow wheels quickly sink into the ground. The stroller must then be either carried or pulled through the sand as the wheels plow troughs along the beach.
In the prior art, there have been many devices developed over the years that are specifically intended to alleviate the burden of carrying a large number of accessories to and from the beach. One prior art approach has been to provide a wheeled vehicle, like a wheelbarrow, that can be loaded with gear and pushed or pulled to the beach. Such prior art devices are exemplified by U.S. Pat. No. 3,693,993 to Mazzarelli et al., entitled Beach Tote Cart and U.S. Pat. No. 5,362,079 to Graham, entitled Beach Caddy. Some of the problems associated with such prior art devices are that such devices are expensive, bulky and labor intensive to manufacture. Often people traveling to the beach or another recreational location have packed their vehicles to capacity and have no extra room for a large bulky wheeled cart.
A second problem associated with such beach carts is they are designed to hold bulk items. The beach carts themselves are not designed to hold small children safely. Consequently, using a beach cart does not eliminate the need to use a stroller.
A need therefore exists for a device that can be attached to a traditional stroller so that the stroller can be readily pulled across sand or loose gravel. In this manner, a baby and much of the baby's gear can be taken to the beach using the stroller, thereby greatly reducing the difficulty of taking a small child to the beach. This need is met by the present invention as described and claimed below.

Assembly for towing a wheeled stroller on sand


Provide is a toner including toner particles each containing at least a binder resin and a colorant, and an inorganic fine powder, in which the inorganic fine powder has a ratio (A/B) of a total pore volume A measured in a pore diameter range of from 1.9 nm or more and to 8.0 nm or less to a total pore volume B measured in a pore diameter range of from 1.9 nm or more and to 300.0 nm or less of from 0.20 or more and to 1.00 or less, and the total pore volume A is from 1.00×10−2 cm3/g or more and to 1.00 cm3/g or less.

1. Field of the Invention
The present invention relates to a toner to be used in an image-forming method or toner jet method for visualizing an electrostatic image in electrophotography.
2. Description of the Related Art
An electrophotographic method involves: charging an electrostatic latent image bearing member composed of a photoconductive substance by various means; exposing the charged electrostatic latent image bearing member to light to form an electrostatic latent image on the surface of the electrostatic latent image bearing member; developing the electrostatic latent image with toner to form a toner image; transferring the toner image onto a transfer material such as paper; and fixing the toner image on the transfer material with one or both of heat and pressure to provide a copied article or print.
When such image-forming process is repeated a large number of times, ozone produced in the charging step of charging the electrostatic latent image bearing member reacts with nitrogen in the air to form a nitrogen oxide (Nox), the so-called corona product. Further, such nitrogen oxide reacts with moisture in the air to form nitric acid, which adheres to the surface of the electrostatic latent image bearing member. As a result, the resistance of the surface of the electrostatic latent image bearing member reduces, and, at the time of image formation, image smearing serving as an image defect on the electrostatic latent image bearing member occurs; the phenomenon is particularly remarkable under a high-humidity environment.
By the way, nowadays, an output apparatus employing electrophotography, which has been conventionally used for personal-use purposes, begins to be used for professional-use purposes; in particular, the apparatus has started to be put into full-fledged use in light printing applications (print-on-demand (POD) applications where a large number of kinds can be printed in small amounts each).
When it is assumed that an electrostatic latent image bearing member is used in a light printing application where high reliability and high durability are requested, an improvement in durability of the electrostatic latent image bearing member requires an increase in surface hardness of the member.
However, when the durability of the electrostatic latent image bearing member is improved as described above so that the electrostatic latent image bearing member can be used in a POD application, the surface of the electrostatic latent image bearing member is hardly shaved and hardly refreshed, so the improvement is disadvantageous for the prevention of image smearing.
In view of the foregoing, the following procedure has been conventionally adopted: a heater for temperature regulation (hereinafter referred to as "drum heater") is provided for the inside of the electrostatic latent image bearing member so that the problem known as "image smearing" is dissolved. However, it has been demanded to perform the removal of the drum heater for energy-saving purposes because the drum heater requires electrification and consumes power even at nighttime during which the drum heater is not used.
In addition, even when such a constitution that corona products on the electrostatic latent image bearing member are removed with an air blow or the like is established, an increase in amount of the corona products to be produced precludes sufficient removal of the products, so it may become impossible to inhibit the occurrence of an image defect with reliability. The frequency at which corona products are produced increases particularly in a high-speed developing system to be used in a POD application, so image smearing is apt to be induced in the system.
To cope with the image smearing, the following approach on a toner side has been conventionally adopted (Japanese Patent Application Laid-Open No. Hei 5-273785): an inorganic fine powder is added to toner, and the image smearing is prevented by the abrasive action of the powder. However, when the approach is employed in the above-mentioned POD application, an electrostatic latent image bearing member is hardly abraded, with the result that corona products cannot be sufficiently removed. In addition, when fine particles each of which can serve as a spacer are added to the toner, a phenomenon in which the spacer particles are liberated occurs, so image defects due to the contamination of the inside of the apparatus and insufficient charging of the member are prompted in some cases.
In view of the foregoing, the following attempt has been proposed: corona products are removed by utilizing a substituting ability which a laminar compound and a porous material each have instead of the abrasive action. For example, Japanese Patent Application Laid-Open No. 2003-066637 proposes a method involving feeding a compound having an acid-receiving effect such as a hydrotalcite compound. The hydrotalcite compound is a laminar compound composed of a positively charged layer and a negatively charged layer. The compound reduces influences of the corona products by the following action: CO32− in the structure of the compound is ion exchangeable, so CO32− adsorbs an acid by easily substituting with any other anion. However, it is hard to say that the compound has a sufficient adsorbing ability because the sites where the ions can substitute are mainly the edge portions of the respective layers.
In view of the foregoing, it has been proposed that zeolite or the like be used as a polar adsorbent (Japanese Patent Application Laid-Open No. 2003-91223). A porous material such as zeolite has a larger number of substitution sites and a higher substituting ability than those of a compound of a laminar structure. However, zeolite as a porous material has a pore diameter as small as about 1.5 nm, and a wall between a pore and an adjacent pore is thin, so zeolite has a low physical strength as a porous material. Since toner is stirred at a high speed particularly in a developing device to be used in a POD application, the following detrimental effect arises: the shapes of porous external additive particles are broken by a sliding action between the particles, and the broken external additive particles affect the parent body of the toner.
It has been proposed that a porous powder impregnated with silicone oil be used as a porous material excellent in stability against a mechanical stress (Japanese Patent Application Laid-Open No. Hei 2-221964). However, the powder is impregnated with silicone oil so that the pores of the powder are filled. As a result, there is a possibility that the pores cannot sufficiently exert their substituting abilities, and corona products cannot be sufficiently removed. In addition, the particles of the powder each have a large particle diameter; specifically, the particles each have a primary particle diameter of from 2 μm or more and to 15 μm or less. As a result, the powder serves as a liberated external additive particularly in a high-speed developing system to be used in a POD application, and the scattering of the powder may lead to the contamination of the inside of the system, or may cause the destabilization of the charging of the system.
Further, it has been proposed that the developing performance of toner be improved by adding a calcium phosphate compound having a porous structure (Japanese Patent Application Laid-Open No. 2002-287414). However, the compound used has a large pore diameter, and cannot sufficiently capture corona products, so the proposal is not a sufficient measure against image smearing.
As described above, at present, no toner capable of achieving compatibility between the removal of a corona product and a combination of high durability and high stability in a high-speed developing system for a POD application using no drum heater is still available.


A flexible wavelength switch fabric may be implemented with multiple groups of reconfigurable blocking filters or with multiple multi-in, single out wavelength selective switches. The behaviors of reconfigurable blocking filters are individually settable, such as channel blocking, channel spacing, transmission rate, and default blocking state. Add and drop taps may be added to provide arbitrary add/drop capability. Optical splitters/combiners used may be tunable so that insertion losses may be minimized for the overall network.

Optical networks provide a tremendous capacity advantage. Entities wishing to take advantage of the advantages that optical networks offer, must usually make a decision based on their current needs (which may be modest and predictable) and their future needs (which are typically unpredictable). An entity may decide to acquire a network to meet its short-term needs because of it's present financial constraints.
However, this approach carries a risk that the network will be insufficient and may cost more in the long run because the entire network has to be replaced due to inadequacies of the network. Also, any upgrades may require the network to be shut down prior to the upgrade. Such a shut down is costly since no service can be provided, which in turn shuts down a revenue stream. In an industry such as telecommunications, shut down can be extremely costly indeed.
Another approach is to project a long-term need and acquire a network with capabilities to meet the long-term need. This approach also carries inherent risks as well. In the short run, the investment in the network will be wasted to the extent that there will be excess capacity. In the long run, the needs of the entity may change in a different direction and the acquired network will not be able to handle the changed needs efficiently.
Conventional add/drop nodes utilize one of two architectures—broadcast and blocking architectures. The broadcast architecture is an architecture in which a copy of an optical signal is dropped to a drop path of a node while another copy continues on a through path. Multiple channels are not allowed to occupy same portions of the spectrum inside the transmission medium due to interference. Thus, channels that occupy a specific portion of wavelengths (or spectrum) prior to the node are not available for use subsequent to the add/drop connectivity. However, other unused portions of the spectrum are available for use subsequent to the node. The broadcast architecture may be sufficient in wavelength division multiplexing (WDM) systems with large aggregate channel capacities.
In a blocking architecture, at least the through path (and often the drop path) is spectrally filtered. This permits wavelength reuse for add/drops in subsequent portions of the network. The reuse of wavelengths provides advantages by making additional channels available for connectivity, thereby increasing the total capacity available on the communications network.
Wavelength selective switches (WSS) (an optical cross connect (OXC) with granularity of single wavelength), for example an N×N WSS, have been widely proposed and studied in the last few years as a cost-effective solution to provide a transparent by-pass for WDM express traffic at degree n nodes in optical networks. WSS's provide an optical cross-connect function with single channel granularity, where any WDM channel from any of the N inputs can be routed to any of the N outputs.
However, even the capabilities of conventional WSS may not be enough to meet the unanticipated demands. Typical implementation of WSS in commercial systems is limited by the maturity of optical components.
An approach is desired where the system deployed is extremely flexible so that future demands on the optical networks, not yet foreseen, may be handled with ease. As the capacity demand grows and changes, it is desired to provide a flexible system that can meet the increased demand and the type of demand changes. It is also desired to have the capability to recover previously inaccessible capacity and without service disruptions.

Flexible wavelength selective switch fabric with arbitrary add and drop capability


A speaker supporting structure, which includes a speaker supporting device with improved assembly characteristics, and an electronic device comprising this speaker supporting device. The speaker supporting device is a structure which supports a speaker mounted in a case, and comprises a main body part which covers a wiring board disposed inside the case, and a mounting part which is formed in this main body part, and on which the speaker is mounted.

1. Field of the Invention
The present invention relates to a speaker supporting device suitable for use in various types of electronic devices having built-in speakers, such as mobile telephones, PHS (personal handyphone systems), other information mobile terminals and the like, and an electronic device comprising this speaker supporting device, and more particularly relates to a speaker supporting structure and assembly structure of an electronic device.
2. Description of the Related Art
Besides a speaker as a receiver that is used to reproduce communications sound, a speaker that is used to reproduce calling sounds and the like is disposed in a mobile telephone. These speakers are reduced in size and weight, and are mounted on wiring boards or on case internal members together with other electronic parts and disposed in the vicinity of respective sound emission holes in the rear side case and front surface side case.
Prior patent references relating to such speaker supporting structures include Japanese Patent Application Laid-Open No. 2002-10387 and Japanese Patent Application Laid-Open No. 2001-127862.
In FIG. 5 and the description of this figure in Japanese Patent Application Laid-Open No. 2002-10387, a structure in which a board on which electronic parts and the like functioning as control parts used to control the driving of the speaker is disposed between a shielding case and an LCD holder, and the speaker is fastened between the shielding case and a rear case while ensuring a front air chamber as a result of the shielding case being pressed by the board and an annular cushion disposed on the outer circumferential part of the speaker being compressed due to the screw fastening of the front case and rear case, is disclosed as a speaker device for mobile telephones and the like.
Furthermore, in Japanese Patent Application Laid-Open No. 2001-127862, a structure in which the speaker is held by a speaker holding member supported on a shielding case which is installed so that this shielding case straddles a printed board is disclosed as a speaker structure which facilitates the fastening and electrical wiring of the speaker.
Speakers that are mounted in mobile telephones are compact speakers with a diameter of approximately 15 mm, and do not have a structure in which the speaker itself is screw-fastened. Instead, as is disclosed in the above-mentioned patent references and the like, a simple supporting structure in which the speaker is sandwiched between other members, or in which the speaker is fastened to a specified member by means of an adhesive tape or the like, is employed.
Seen from the standpoint of the speaker alone, such supporting structures are extremely simple structures. However, in electronic devices such as mobile telephones or the like in which the mounting density of electronic parts is high and the speaker must be installed in a constricted space, the attachment of the speaker causes a deterioration in the assembly characteristics of such electronic devices such as mobile telephones or the like. Such a problem is not disclosed in the above-mentioned patent references, and cannot be solved by the techniques disclosed in these patent references.

Speaker supporting device and electronic device comprising this speaker supporting device


An occupant detection system for detecting an occupant on a seat of a vehicle includes an antenna electrode in a seat bottom of the seat, and an electronic unit connected to the antenna electrode and the vehicle. The electronic unit applies a load current to the antenna electrode so as to generate a weak electric field, and detects a potential current passing through the antenna electrode. The electronic unit detects an occupant based on an impedance and a phase difference, which are based on the load current and the potential current.

1. Field of the Invention
The present invention relates to an occupant detection system for detecting an occupant on a vehicle seat and a method of determining the occupant.
2. Description of Related Art
An air-bag device is mounted in a vehicle in order to reduce damage to an occupant when the vehicle collides with an object such as another vehicle. The air-bag device is provided in a passenger seat in addition to a driver seat. The air-bag device is actuated, when a calculating unit of the air-bag device determines that the vehicle collides with the object. The calculating unit performs calculations based on signals output from a sensor, e.g., acceleration sensor, on the vehicle.
The air-bag device is set to be actuated, whenever the vehicle collides with the object, even if any occupant is not seated on the passenger seat. However, the air-bag device is not to be actuated, when a body size of the occupant is small. An adult can be protected by the air-bag device, when the vehicle collides with the object. In contrast, for example, a child may not be protected by the air-bag device, and rather a head of the child may be damaged by the air-bag device, because the head of the child is positioned lower than that of the adult.
In order to determine whether the occupant is an adult or not, an occupant detection system having an occupant detection sensor is provided on the passenger seat. For example, Japanese Patent No. 3346464 discloses an occupant detection system for detecting an occupant and its seating state. The occupant detection system includes plural pairs of antenna electrodes in the passenger seat, so that one of the pairs of antenna electrodes can detect the occupant.
However, if the passenger seat is wet, detection accuracy of the system may be lowered. In this case, because whole wet part operates as an antenna, an erroneous output larger than a correct output may be output. Thus, the system may determine the occupant to be an adult, while the occupant is a child. As a result, the air-bag device may be erroneously actuated.
In contrast, U.S. Pat. No. 6,816,077 (corresponding to JP-A-2002-347498) discloses an occupant detection system having a moisture sensor in a seat. This system can have high detection accuracy, because erroneous detections due to moisture in the seat can be reduced. However, the moisture sensor causes an increase in its product cost.
Moreover, US 2005/0128082 A1 (corresponding to JP-A-2003-504624) discloses an occupant-detecting device including an electric field sensor and a detection circuit. The detection circuit applies vibration signals to an electric field such that the vibration signals are most weakly affected by moisture in a seat. However, affects caused by the moisture cannot completely be eliminated.

Occupant detection system and method of determining occupant


A module evaluation method and system which can quickly determine overall effectiveness of the modular construction method in an automatic manner, taking into account the transportation cost and so on. A module evaluation unit prepares constructed-equipment physical quantity data from constructed-equipment layout data, and determines an in-module unit-rate reduction effect resulted from executing construction work of the constructed equipment in the module in a factory where working efficiency is higher than a field. The module evaluation unit also determines a module transportation cost effect, a module temporary construction cost effect, and a density reduction effect that is resulted from a reduction of density in a space not occupied by a module with application of modularization and efficiency of installation work is increased. The module evaluation unit further determines a field physical-quantity reduction effect resulted from a reduction of physical quantity in the field and from a reduction of various overhead costs with application of the modularization. The determination results are displayed on a display.

1. Field of the Invention
The present invention relates to a module evaluation method and system for use with a modular construction method which is one of construction methods for plants, etc.
2. Description of the Related Art
The term "modular construction method" means a method for constructing and installing plant equipment through steps of prefabricating the equipment, such as piping and devices adjacent to each other, into modules, i.e., units of assembly constructed beforehand, transporting the modules to an installation site in a plant, and installing the modules in integral structure.
By utilizing the modular construction method, assembly work can be performed in a factory where environment is better and the work cost is lower than those in the site or field, thus resulting in a reduction of the total cost due to a reduction of the assembly and installation cost, etc. Also, lump wok for installation of the individual modules can reduce the amount of required field work that is subjected to severe method restrictions, thus resulting in a cut of the construction term.
The effect of the modular construction method depends on the arrangement of constructed equipment even in the same plant or in the same area within the plant. Namely, when the modular construction method is applied, the resulting effect is high in some area, is low in other area, and is minus in still other area. It is therefore important to select modules providing a high effect. Further, because design work required for the modular construction method is not performed when the modular construction method is not employed, such design work has to be effectively performed to minimize an additional cost.
Patent Document 1 (JP,A 10-143236) discloses one known technique for determining effectiveness of a modularization range in a plant. This disclosed technique determines effectiveness of the modularization based on assembly workability of structural components within the range of a module.
Also, Patent Document 2 (JP,A 2002-355724) discloses one known technique for automatically performing assembly and disassembly steps of general products. This disclosed technique determines the assembly and disassembly cost based on robot simulation of the assembly and disassembly steps of the products, and then determines the propriety of the assembly and disassembly steps depending on the amount of the cost.