A method for preparing a release coating and applying it to crucibles used to contain molten material while it solidifies, by mixing a release coating power with a dry organic binder into a powder and binder dry mixture, mixing a defoamer with a liquid into a liquid and defoamer mixture, mixing the dry mixture with the liquid and defoamer mixture into a wet release coating, sieving to remove lumps and particles, checking the viscosity, wet-spraying onto a crucible, evaporating the liquid from the wet release coating so as to leave a dry release coating on the crucible, and separating the binder from the dry release coating by thermal decomposition.

The invention relates to preparation and application of release coatings for crucibles used in the handling of molten materials that are solidified in the crucible and then removed as ingots, and more particularly to release coatings for crucibles used in the directional solidification of polycrystalline silicon.
Crucibles of fused-silica (quartz) are typically used in directional solidification of polycrystalline silicon. Quartz is chosen primarily for high-purity and availability. There are problems in using quartz, however, as a crucible for the production of silicon by this method.
Silicon in its molten state will react with the quartz crucible that is in contact with it. Molten silicon reacts with quartz to form silicon monoxide and oxygen. Oxygen will contaminate the silicon. Silicon monoxide is volatile, and will react with the graphite components inside the furnace. Silicon monoxide reacts with graphite to form silicon carbide and carbon monoxide. The carbon monoxide will then react with the molten silicon, forming additional volatile silicon monoxide and carbon. Carbon will contaminate the silicon.
The reaction between quartz and silicon promotes adhesion of the silicon to the crucible. This adhesion, combined with a difference in coefficients of thermal expansion between the two materials, creates stress in the silicon ingot, causing it to crack on cooling. It is known in the art that a release coating applied to the inside of the crucible in the area of contact with the ingot can prevent the reaction between silicon and quartz that leads to ingot contamination and cracking. To be effective, the release coating must prevent the silicon from reacting with the quartz crucible, and must not adversely contaminate the silicon either by itself or from contaminants within it.
A variety of materials and techniques are described in the literature, which attempt to solve the problem of reaction and adhesion of the crucible in contact with molten material. For example, U.S. Pat. No. 4,256,530 by Schmid et al., suggests coating the outside of a quartz crucible with a refractory material, to prevent reaction with adjacent carbon components. The coating does not contact the molten silicon. The method of preparing and applying the coating are, however, undisclosed.
U.S. Pat. No. 5,431,869 by Kumar, et. al., describes a multi-component release agent of silicon nitride and calcium chloride for silicon processing using a graphite crucible. The silicon nitride coating is applied as a slurry in an organic binder and solvent. The method of preparation and application are largely undisclosed. It is suggested that the binder can be removed after the coating, but the details are undisclosed. The calcium chloride portion is introduced with the bulk silicon, rather than as a coating, to the silicon-nitride coated crucible. The use of silicon nitride alone is described as unfavorable as a crucible coating for directional solidification of silicon.
U.S. Pat. No. 4,741,925 by Chaudhuri, et. al., describes a silicon nitride coating for crucibles applied by chemical vapor deposition at 1250 degrees Centigrade. U.S. Pat. No. 3,746,569 discloses the pyrolysis formation of a silicon nitride coating on the walls of a quartz tube. The process requires application temperatures at least 800 degrees C, and tempering at 1250 degrees Centigrade. U.S. Pat. No. 4,218,428 by Schmid, et. al., describes a technique of forming a glass layer inside a silica crucible by rapid heating to prevent cracking of silicon during melt-processing.
U.S. Pat. No. 3,660,075 by Harbur et al., discloses a coating of niobium carbide or yttrium oxide on a graphite crucible for melting fissile materials. The niobium carbide is applied by chemical vapor deposition, while the yttrium oxide is applied as a colloidal suspension in an aqueous inorganic solution. Details such as the method of preparation and application are largely undisclosed. U.S. Pat. No. 3,613,633 by Anderson, describes a heated rotating crucible used to hold articles to be coated. The crucible facilitates the containment of an xe2x80x9cevaporantxe2x80x9d which coats the articles therein. The crucible itself is not, however, used to contain molten material.
Reference is made in xe2x80x9cLiquid Encapsulated Bridgman (LEB) Method for Directional Solidification of Silicon Using Calcium Chloridexe2x80x9d, by P. S. Ravishankar, Journal of Crystal Growth, 94 (1989) 62-68, to the coating of a silica crucible with silicon nitride. However, no method is detailed for preparing and applying the coating. Furthermore, the resulting ingot quality using this coating is described as poor, due to particle nucleation leading to poor grain-growth and low solar cell efficiency.
Saito, et. al., in xe2x80x9cA Reusable Mold in Directional Solidification for Silicon Solar Cellsxe2x80x9d, Solar Energy Materials, vol 9, (1983) pg 337-345, and in xe2x80x9cA New Directional Solidification Technique for Polycrystalline Solar Grade Siliconxe2x80x9d, Conf. Record of 15 th PV Specialists Conference, 1981, p 576-580, describes a coating of silicon nitride powder which is brushed onto a quartz, silicon carbide coated carbon or silicon nitride sintered mold. The powder is suspended in an organic solvent, which is evaporated by heating. Methods of preparation and application are not detailed, except that the coating needs to be at least 150 microns thick.
Saito reports, xe2x80x9cThe [silicon nitride] powder was mixed together with a suitable amount of organic solvent, such as liquid polyvinylalcohol, to form a slurry. The slurry was coated by a brush on the inner crucible walls. Then, the crucible was heated in an air ambient at 600 C. for 30 minutes to burn out the organic solvent. The coated layer thus obtained had good mechanical strength against scratching.xe2x80x9d However, no method is detailed for preparing and applying the coating. Brushing, we have found, is a difficult way to obtain a uniform coating.
Scaling a laboratory process such as Saito""s up to production requirements is also problematic. Saito""s crucible was only a few inches across, and contained only 225 g of molten material, while the present technology requires crucibles over two feet across, and contains over 240 kg of molten material. The difference in size and weight makes the physical demands on the coating and the coating process much more profound.
Other publications that mention crucible coatings, usually of silicon nitride, for directional solidification of silicon, but do not discuss methods of preparation or details of application, include: xe2x80x9cHEM Technology for Photovoltaic Applicationsxe2x80x9d, Khattak et al, 6th IPSEC Conference, New Delhi, India, 1992, p 117-124; xe2x80x9cGrowth and Characterization of 200 kg Multicrystalline Silicon Ingots by HEMxe2x80x9d, 26th IEEE PVSC Conference, Anaheim, Calif., Sep. 29-30 1997; xe2x80x9cGrowth of 240 kg Multicrystalline HEM Silicon Ingotsxe2x80x9d, 2nd WCPEC Conference, Vienna, Austria, Jul. 6-10 1998; xe2x80x9cHigh Efficiency Solar Cells Using HEM Siliconxe2x80x9d, First WCPEC Conference, Dec. 5-9, Hawaii, 1994 p 1351-1355; xe2x80x9cCharacteristics of HEM Silicon in a Reusable Cruciblexe2x80x9d, 23rd IEEE PV Specialists Conference, Louisville, Ky., May 10-14, 1993, p 73-77; xe2x80x9cAnalysis and Control of the Performance-Limiting Defects in HEM-Grown Silicon for Solar Cellsxe2x80x9d, Material Research Society Symposium Proceedings, 1995, v 378 p 767-776; xe2x80x9cLifetime Improvement of Multicrystalline Siliconxe2x80x9d, Habler et al., 14 th EPVSE Conference, Barcelona, Spain, Jun. 30-Jul. 4, 1997, p 720-723; xe2x80x9c3D Distribution Study of Impurities into a Polix Ingotxe2x80x9d, Borne et al., 13th European PV Conference, Nice, France, 1995, p 1340-1343; xe2x80x9cStudy and Conditioning of Defect Areas in Eurosil Multicrystalline Siliconxe2x80x9d, Acciarri et al., 13th European PV Conference, Nice, France, 1995, p 1336-1339; and xe2x80x9cSelection of a Crucible Material in Contact with Molten Siliconxe2x80x9d, Revel et al., 5th EC PV SEC, Athens, Greece, Oct. 17-21 1983, p 1037-1042.
Prior art references include specific references to powdered mold release agents for application to crucibles in the directional solidification of silicon. In addition, the use of chemical vapor deposition, solvent evaporation, high-temperature flame treatment, and other expensive and complex means are mentioned for application of crucible coatings. References are made to specific binders and solvents. Although there is a tremendous emphasis in the literature on controlling the purity of the molten material, such emphasis is lacking in the prior art references as to the powder coating process. Silicon Nitride, for example, is available in a variety of phases, purity, and particle size, which may or may not make them suitable for coating.
References are made to mixing, spraying, or brushing for slurries of powdered coatings. There is no mention, however, of a method to mix, spray, or brush the coating in such a way as to control physical properties such as viscosity, foam content, dispersion quality, in order to provide a uniform coating on the crucible and to avoid contaminating the coating in the process of carrying out these steps.
We have discovered, for example, that the use of a specific silicon nitride powder, Baysinid(R), disclosed by Habler et al., in xe2x80x9cLifetime Improvement of Multicrystalline Siliconxe2x80x9d, 14th EPVSE Conference, Barcelona, Spain, Jun. 30-Jul. 4, 1997, p 720-723, in preparing crucible coatings, is heavily aggregated and difficult to disperse, created a poor suspension which was unstable, and caused spraying equipment to clog. This resulted in an extended time required for coating application, and a non-uniform coating which is not reliable in preventing adhesion of molten silicon to the crucible. Ingots were sometimes cracked during operations in which this material was used, due to difficulties related to poor dispersion and clogging. Milling operations using conventional means to properly grind the aggregates to form a stable suspension would contaminate the coating with metal or metal oxide that would contaminate molten silicon.
These examples illustrate how the reviewer of the prior art is led to believe that the selection of specific components and details of their preparation are obvious. We have found, however, that the selection of powders, binders, solvents, and their preparation for applying as a reliable and high-quality coating to a crucible is not in fact obvious, but requires substantial inventiveness to accomplish.
It is an object of this invention to provide a simple, inexpensive coating system and application process for coating crucibles with a release coating for use in a production environment for the manufacture of ingots of polysilicon or other materials. The system will preferably include a coating material having suitable crucible adhesion and ingot release characteristics when applied to a crucible as a release layer for the molten material, and for which there is a powered form of the material available with a suitable particle size and dispersibility for spray application using commercial equipment and conventional methods.
There will be a safe and inexpensive liquid solvent for the coating material, preferably water, in which to suspend the powder, and an organic binder possessing physical and chemical characteristics that facilitate the application of the coating system to crucibles using commercially available spraying equipment. The coating may include additives to improve its quality, make it more sprayable, easier to apply uniformly, and improve its mixing characteristics and control its physical properties. The powder, binder, and solvent are selected and processed such that the resulting final release coating on the crucible does not adversely contaminate the molten material.
It is a further object of the invention to provide a means to remove the solvent from the coating and harden the binder to prevent movement of the coating during subsequent processing, such as by preheating or holding the crucible at a slightly elevated temperature so as to facilitate the evaporation of the solvent and drying of the coating on the crucible after the spraying operation.
It is another object to provide a means to remove the binder by thermal decomposition from the coating and to densify the final coating so as to minimize damage to the coating during subsequent processing of the molten materials, such as by bisque-firing firing the crucible by slowly heating the crucible in oxidizing air to well above a temperature at which the binder material will be readily oxidized dispersed into the air, maintaining the crucible at or near that temperature for a period of time to assure hardening of the remaining layer, and allowing it to cool slowly to room temperature.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein we have shown and described only a preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by we on carrying out our invention.


A circuit arrangement for independently switching the induction coils of several d.c.-operated solenoid valves connected in parallel that, with a reduction of power loss, features a disconnection time which is independent of the voltage of the d.c. voltage source.

In motor vehicles, systems are increasingly being integrated whose function is based on the rapid switching of inductive switching units with inductive loads. As a rule, these inductive loads are the induction coils of powerful, d.c.-operated solenoid valves. In order to switch off an inductive load quickly, it is necessary to transform the energy stored in its magnetic field as quickly as possible.
A commonly used circuit which accelerates the decay of the energy stored in an inductive load is a free-wheeling switch in series with a free-wheeling diode, the two together forming a free-wheeling circuit through which the inductive load can be short-circuited and which is connected in parallel to the inductive load and its main switch. In order to switch off the inductive load, the free-wheeling switch is closed at the same time as the main switch is opened. In so doing, the field strength of the magnetic field of the inductive load decays rapidly and the energy of the magnetic field is transformed into heat energy and as a result the switching off of the inductive load is completed at a faster rate. However, the energy stored in the inductive load is then completely lost; the power loss in the circuit arrangement is then maximum. Also, the free-wheeling circuit, in particular the free-wheeling switch, must be designed for the high voltage peaks that occur when the inductive load is short-circuited.
In circuit arrangements such as, for example, the so-called four-quadrant circuit according to U.S. Pat. No. 5,621,604 several inductive switch units, connected in parallel and supplied from a d.c. voltage source, can be switched independently of each other with a minimum of power loss. An inductive switch unit consists of an inductive load and a main switch between which a blocking diode, connected in the reverse direction to the minus pole, is contacted.
In the four-quadrant circuit, the power loss that occurs when switching off the inductive load is minimized by feeding back the current induced by the inductive loads in the circuit to the d.c. voltage source of the cicuit arrangement. Furthermore, the free-wheeling circuit, which is arranged with a free-wheeling diode in parallel to the inductive switch units, is connected through a free-wheeling switch to the minus pole of the d.c. voltage source.
When activating (i.e., allowing current to flow through) an inductive load, the main switch of the inductive switch unit concerned and the free-wheeling switch are closed. A current then flows from the d.c. voltage source through the main switch and the inductive load of the inductive switch unit concerned and through the free-wheeling switch to the minus pole of the d.c. voltage source.
After the free-wheeling switch has opened, the circuit arrangement is in the free-wheeling phase where the current flows in a closed circuit made up of the main switch and inductive load of the inductive switch unit concerned together with the free-wheeling diode.
To end the active circuit state of an inductive switch unit, the main switch of the inductive switch unit is opened. This causes the inductive load to induce a current in a circuit made up of the inductive load and the blocking diode of the inductive switch unit concerned together with the d.c. voltage source. As a consequence, the energy of the inductive load is fed back to the d.c. voltage source of the circuit arrangement with very little energy being transformed to heat and with a minimum loss of power in the circuit arrangement.
This circuit arrangement does, however, suffer from the serious disadvantage that the disconnecting time, within which the energy stored in the inductive load can be fed back to the d.c. voltage source, depends on the voltage of the d.c. voltage source of the circuit arrangement.
Consequently, the disconnecting time of the so-called four-quadrant circuit is increased drastically compared with the conventional circuit arrangement, especially when the d.c. voltage source supplies low voltages (below 20 volts).
The object of the invention is to provide an improved circuit arrangement that has advantageous properties with regard to the loading of the free-wheeling switch, the disconnecting time of the inductive load, and the power loss at the time of

Circuit arrangement for mutually independant switching of several inductive switching units in paralell


A structure of a capacitor on a semiconductor wafer including the following structure is disclosured herein. A first electrode is formed on the semiconductor wafer. The first electrode includes a flower structure. The first electrode is formed on the semiconductor wafer. The first electrode includes a flower structure. The first electrode includes a flower neck portion, a flower bottom portion, and a flower top portion. The flower neck portion is electrically coupled to the semiconductor wafer. The flower bottom portion is electrically coupled to the flower neck portion, in which the flower bottom portion includes a first protudent portion. The flower top portion includes a downward hemispherical portion and a second protrude portion. The flower top portion is electrically coupled to the flower neck portion. A first dielectric film formed on the first electrode, and the first dielectric layer is the dielectric layer of the capacitor. A second electrode is formed on the first dielectric film.

Dynamic Random Access Memory (DRAM) devices have been applied in the integrated circuits for many years. A DRAM cell is in general a semiconductor memory device with one transistor and one capacitor, in which data of 1-bit can be stored by the charge stored therein. Indeed, a memory cell is provided for each bit stored by a DRAM device. Each memory cell typically consists of a storage capacitor and an access transistor. The source of the access transistor is connected to one terminal of the capacitor. The transistor drain electrode and the gate electrode are connected to external connection lines called a bit line and a word line, respectively. The other terminal of the capacitor is connected to a reference voltage. Therefore, the formation of a DRAM memory cell comprises the formation of a transistor, a capacitor and contacts to the external circuits.
As a tendency to the higher density of an integrated semiconductor device, it causes the density of the DRAM cells to be increased, and the area occupied by one memory cell becomes gradually decreased. Due to the trend of making the semiconductor devices, the sizes of the memory cells have gotten smaller and smaller. Thus, the area available for a single memory cell has become very small. This has caused a reduction in the area occupied by the capacitor, and has resulted in a reduction of the capacitance of a cell. For the very small memory cells, planar capacitor has become very difficult for use reliably. Specifically, as the size of the capacitor is decreased, the capacitance of the capacitor is also decreased and the amount of the charge capable of being stored by the capacitor is similarly decreased. Therefore, the present invention is devoted to the manufacture of a capacitor with a maximum capacity in a limited area.
Prior art with the approach to overcome these problems, has resulted in the development of the various types of capacitors. One of the capacitors has the bathtub-shaped structure. The process is operated with the characteristic that the staked capacitor has more capacitance than that of the planar type capacitor. In order to increase the capacitance of the capacitor, the thickness of the dielectric film of the capacitor is reduced, and the area of the electrodes of the capacitor is increased by overcoming the limitation of the lithography technique. In other words, the area of the electrodes in one memory cell is increased without the problem of step coverage. Please see "Method For Fabricating Staked Capacitors In A DRAM Cell, Jin-Suk Choi. et al., U.S. Pat. No. 5,104,281". Yet, the shape of the storage node of the memory cell is like a bathtub, and the height of the electrode is not extended, so that the area of the electrodes is not largely increased.
Further, a capacitor over bit line (COB) cell with a hemispherical grain silicon storage node has been developed (see "Capacitor Over Bit Line Cell With Hemispherical Grain Storage Node For 64 Mb DRAMs", M. Sakao et al., microelectronics research laboratories, NEC Corporation, IEDM Tech Dig., December 1990, pp655-658). The HSG-silicon is deposited by low pressure chemical vapor deposition method at the transition temperature from amorphous silicon to polycrystalline silicon. This memory cell provides high capacitance by increasing the effective surface area of a simple storage node. The present invention increases the effective area of the electrodes of the capacitor without the usage of the HSG-silicon; thus the process is simplified.

Stacked capacitor structure for high density DRAM cells


Embodiments of a method and a system are provided to create a uniform layer of a substance such as a hydrogel or other fluid substance underneath the soil surface with minimal or little surface disturbance to the plants, the plant roots and the soil located on or slightly below the applied surface area. It is to be clearly understood that various different embodiments may be employed to deliver a variety of different substances to the soil, and such substances may be gels or liquids. The presently preferred fluid substance is currently a hydrogel, and the present illustrated and described embodiment may be employed to inject hydrogel into soil but other fluid substances may be injected as well.

There is no admission that the background art disclosed in this section legally constitutes prior art.
The use of fluid substances such, for example, as hydrogels or liquids as a soil amendment or other is well established. There are a number of different types of fluid substances including liquids and gels have been injected into the soil to help plant growth. For example, polyacrylamide (PAM), starch and polyacrylate gels have been used for this purpose. Use of hydrogels allows the retention of moisture in the soil or around crop roots. Substantial reduction in the use of irrigation water may be achieved by applying appropriate dosages of PAM to soil or other growing mediums for many applications. Reduction in the amount of irrigation water applied in agricultural and landscape applications may have the additional benefit of slowing the build-up of unwanted salts introduced through irrigation water. Additionally, additives may be incorporated into hydrogels, thereby effecting large savings in the amount of additives used, and consequently, in the amount of additives released to the environment. Such additives may include fertilizers and pesticides as well as others.
For record purposes, the following is a list of prior patents and applications disclosing various methods and devices for applying products to the soil: U.S. Pat. Nos. 1,871,529; 2,214,083; 2,789,522; 3,017,200; 3,148,643; 3,602,166; 3,791,322; 3,926,131; 4,018,170; 4,034,686; 4,178,860; 4,850,291; 5,115,750 and 5,667,019; and U.S. patent applications Nos. 2002/0148396 and 2006/0230997.
A variety of machines have been developed to facilitate the placement of hydrogels below the soil surface. These include tractor powered units that open up the soil surface through the use of specially designed plows and then drop dry granular material into the open slit. Other hand-held machines may use water and/or air to assist with insertion and transport of hydrogel solutions into soil at various depths through an injection device such as a hollow needle or spike. Landscape applications may require application of hydrogels in areas that have existing landscaping such as turf, shrubs and trees. Therefore, a machine used for many such applications should be maneuverable and compact.
A number of methods for applying hydrogels are known in the art. These include broadcasting, mixing with soil, or filling holes in the soil with a mixture of gel and a soil mix. These methods are all discussed in product literature from various manufacturers and/or distributors of these materials. Most methods are labor intensive, often involve an additional step in the planting process, and may cause damage to existing crops, plants, or turf. Each of these factors may contribute to inefficient use of the gel. Furthermore, each of these factors suffer from the disadvantage that they fail to distribute a uniform and consistent layer of the somewhat viscous gel below the surface of the soil to hold water for the plant roots. In short, the prior known distribution techniques have failed to effectively and efficiently deposit desired quantities of fluid substance below the surface of soil in a uniformly consistent manner to help plant growth or otherwise serve as an effective soil amendment.


In a power converter having an input coupled to a power switch and a rectifier for conducting currents from the input to an output of the power converter, a snubber circuit for, a method of, moderating reverse recovery currents associated with the rectifier and a power converter employing the circuit or the method. In one embodiment, the circuit includes a snubber inductor and snubber capacitor coupled to the rectifier. The circuit further includes a first auxiliary switch that conducts to divert a portion of the currents away from the rectifier through the snubber inductor and snubber capacitor. The circuit still further includes a second auxiliary switch, interposed between the power switch and the first auxiliary switch, that conducts to create a path to discharge the capacitor to the output of the power converter.

A power converter is a power processing circuit that converts an input voltage waveform into a specified output voltage waveform. A switched-mode power converter is a frequently employed power converter that converts an input voltage waveform into a specified output voltage waveform. A boost power converter is one example of a switched-mode converter that converts the input voltage to an output voltage that is greater than the input voltage. Typically, the boost power converter is employed in off-line applications wherein power factor correction is required and a stable regulated voltage is desired at the output of the power converter.
A non-isolated boost power converter generally includes an energy storage device (e.g., an inductor) coupled between the input voltage and switching device. The switching device is then coupled to an output rectifier (e.g., a power diode) and an output capacitor. The load is connected in parallel to the capacitor. Again, the output voltage (measured at the load) of the boost power converter is always greater than the input voltage. When the switching device is conducting, the diode is reverse biased thereby isolating the output stage. During this period, the input voltage supplies energy to the inductor. When the switching device is not conducting, the output stage receives the energy stored in the inductor for delivery to the load coupled to the output of the converter.
Analogous to all types of power converters, a boost converter is subject to inefficiencies that impair the overall performance of the power converter. More specifically, the rectifying diode suffers from a reverse recovery condition thereby producing excessive power losses in both the rectifying diode and the switching device and oscillations in both current and voltage therefrom. The effect of the reverse recovery condition is more severe in non-isolated converters, such as the boost power converter. The reverse recovery condition can also detrimentally affect the longevity of the components, especially the rectifying diode and switching device, of the boost power converter. Therefore, efforts to minimize the losses associated with the rectifier and switching device and, more specifically, with the rectifying diode will improve the overall performance of the power converter.
A traditional manner to reduce the losses associated with the rectifying diodes is to introduce a snubber circuit coupled to the rectifying diodes. Snubber circuits are generally employed for various functions including to minimize overcurrents and overvoltages across a device during conduction and non-conduction periods and to shape the device switching waveforms such that the voltage and current associated with the device are not concurrently high. For instance, with respect to rectifying diodes, a snubber circuit may be employed to minimize oscillations in both voltage and current and power losses associated therewith due to reverse recovery currents resulting from a snap-off of the rectifying diode during a transition from a conduction to non-conduction mode of operation.
Snubber circuits are well known in the art. One approach to reduce the reverse recovery currents of the rectifying diode is to employ a snubber circuit that includes an inductor in series with the rectifying diode. This type of snubber circuit attempts to recover the energy stored in the snubber inductor during the reverse recovery period of the rectifying diode for delivery to the output of the converter. While the inductor snubber provides an alternative for reducing the reverse recovery currents of the rectifying diode, there are tradeoffs in the selection of the inductor and auxiliary components of the snubber that detract from the advantages of employing such a snubber circuit.
For medium and high power applications, it may be advantageous to employ a pulse width modulated (PWM) boost converter operating in a continuous conduction mode (CCM). It has been identified, however, that the efficiency and maximum switching frequency of a conventional PWM boost topology is limited by the losses resulting from the reverse recovery currents of the output rectifier. A simple way of minimizing these losses is to limit the rate of change of the current (di/dt) through the output rectifier as it turns off. Different alternatives have been suggested to implement this solution. For cost sensitive applications, a passive snubber (such as the inductor snubber described above) may be used. For applications where higher efficiency is necessary, an active snubber circuit may be employed in the PWM boost converter.
Active snubber circuits generally employ a switch and driving circuitry and energy recovery components. While active snubbers enjoy efficiency improvements over passive snubbers, the efficiencies may still further be improved. This is especially important in view of the more arduous operating conditions for the power converters thereby amplifying the necessity for higher efficiency converters. In many applications, for instance, power supplies are subject to environments having a wide range of temperatures in a convection or conduction cooling environment (i.e., no fans). Therefore, improved converter efficiencies are becoming mandatory to meet difficult conditions thereby further supporting the need for more efficient snubber circuits that temper losses in the converter such as reverse recovery currents from the output rectifier.
Accordingly, what is needed in the art is a circuit that moderates a reverse recovery current of a rectifier that maintains the advantages associated with lossless snubber circuits, but overcomes the deficiencies presently available in the design thereof.

Snubber circuit for a rectifier, method of operation thereof and power converter employing the same


An enzyme preparation containing cellulases and/or hemicellulases is reacted on a homogeneous aqueous suspension of paper pulp having a Schopper-Riegler (SR) degree determined in accordance with standard NFQ 50 003 of at least equal to 25. A paper pulp based on recycled fibers is treated.

1. Field of the Invention
The present invention relates to the papermaking industry and in particular to the recycled paper, industry. More specifically, its object is a new method for treating paper pulps using an enzyme solution.
2. Background of the Prior Art
More and more the papermaking industry uses recycled papers. For example, for the manufacture of corrugated cardboard, more and more often raw materials are used which are based on recycled fibers and, at the same time, the number of recyclings is increased. With each recycling, the quality of the raw materials is lessened. To obtain a satisfactory level of mechanical characteristics, refining of the pulps in an aqueous suspension is generally carried out, which leads to difficulties in machinability.
The pulps in aqueous suspension which are ready to be worked on a paper machine can be characterized by various parameters, one of which is particularly significant for predicting the draining capability of the pulp. Thus, the Schopper-Riegler (SR) degree of a pulp is defined as being an element of appreciation of the quality of a pulp for the manufacture of paper. The SR expresses the capability of water to separate from the suspension under conditions defined by standard NFQ 50 003. On a scale going from 0 to 100; a high SR value means a low suspension draining speed whereas a low value means a more rapid draining speed. It has been noted, for example, that a pulp which has undergone a refining- operation has an SR which is more or less increased depending on the degree of refining to which it has been subjected, as compared to a pulp which has not undergone or has only slightly undergone such an operation.
This parameter plays a particularly important role in the yield of the paper machine. In effect, in order to increase the yield, the draining phase must take as little time as possible. For suspensions with a high SR, it is necessary to increase the concentration of the pulps in order to maintain the same manufacturing rate. This causes poorer sheet formation since the fibers are more difficult to distribute. It is therefore particularly advantageous to have suspensions with a fairly low SR.
It is considered that when the suspensions have an SR of greater than 25, it becomes desirable to attempt to lower it in order to improve the paper manufacturing conditions. Such a lowering is desirable for two reasons: on the one hand, the yield on the paper machine can be improved due to the acceleration of the draining; on the other hand, the rates of manufacture can be maintained without having to compensate for the slowness of the draining with a lesser dilution of the suspension, and with the risks that such would cause poor sheet formation.
The invention seeks to provide a method for treating papermaking pulps in aqueous suspension, such as suspensions based on recycled fibers, having an SR at least equal to 25 which, through the use of enzymes, enables the SR to be lowered and therefore improves the draining of the suspension and the yield of the method for forming the paper.
In the papermaking industry a certain number of methods are known which call for enzyme preparations.
For example, from French Patent FR 2,557,894, a method is known for treating papermaking pulps with an enzyme solution which assists the refining of the pulp, and renders it capable of being transformed into a paper having defined characteristics. In accordance with this method, a particular enzyme solution containing xylanases is reacted on an unrefined pulp which, therefore, has a fairly low SR on the order of 10.
This method seeks, therefore, not to improve the draining of the treated pulp, but to improve its capability of being refined.
From Canadian Patent CA 758,488, a method is also known for refining a papermaking pulp which consists of submitting an unrefined pulp to the action of an enzyme solution which is based in particular on cellulase, pectinol or lipase, and of submitting it simultaneously to mechanical refining. The object sought is also the improvement of the refinement of the treated pulp.
From French Patent FR 2,571,738, a method is also known for treating a papermaking pulp in accordance with which, with a view to providing the pulp with the characteristics of a pulp for chemical usage, an enzyme preparation containing fungic cellulases having a C.sub.1 activity and a C.sub.x activity is introduced to the pulp.

Method for treating a paper pulp with an enzyme solution


An image forming apparatus which enables double-sided image formation using a sheet feeding unit, and is capable of discharging a sheet, whose sheet length is undetermined by the time the sheet reaches a branch area in conveyance for double-sided image formation, without guiding it to a sheet inverting unit. A conveying flapper switches a destination for a sheet to a first conveying path leading to a sheet inverting unit or a second conveying path leading to a sheet discharge tray. A length of a sheet in a conveying direction is detected while the sheet is being conveyed. When a size of the sheet is undetermined, and the length of the sheet is not detected by the time the sheet reaches the conveying flapper, the conveying flapper is controlled so as to convey the sheet with an image formed on a first side thereof to the second conveying path.

1. Field of the Invention
The present invention relates to an image forming apparatus which is capable of forming images in a double-sided mode.
2. Description of the Related Art
Conventionally, there have been image forming apparatuses such as copiers, printers, and facsimile machines, which have not only sheet feeding cassettes in which regular-size sheets are housed, but also, for example, a manual feed tray as a sheet feeding unit from which sheets of various irregular sizes (sizes that are not regular) can be fed. Some of such image forming apparatuses are able to detect a length of a sheet, which is placed on the manual feed tray, in a width direction (direction perpendicular to a conveying direction).
As described in U.S. Pat. No. 5,689,759, there is known an apparatus which, based on information on a sheet width obtained by width detection on a manual feed tray, displays prospective regular sizes on an operation unit and prompts a user to select a sheet size.
As described in Japanese Laid-Open Patent Publication (Kokai) No. H07-33G228, there is also known an apparatus which, based on an output from a sensor on a sheet conveying path in a case where a sheet with unknown size is conveyed from the manual feed tray, determines a sheet length of a sheet, which is fed from a manual feed tray, in a conveying direction and controls a bring-in gate of an intermediate tray in accordance with the sheet length.
In general, when double-sided image formation is to be carried out in an image forming apparatus, there may be sheets which can properly pass a double-sided path, on which a sheet with an image formed on a first side (front side) thereof is conveyed, and sheets which cannot properly pass the double-sided path. For example, when a sheet length in a conveying direction is shorter than a distance between sheet conveying rollers placed on the double-sided path, a sheet cannot be delivered between the sheet conveying rollers, and the sheet cannot pass the double-sided path. When such a sheet whose sheet length is too short is used, an automatic double-sided mode cannot be executed.
In an apparatus which has an inversion path for inverting a sheet when conveying it to a double-sided path, a sheet whose sheet length in a conveying direction is longer than a length of the inversion path cannot be inverted. Thus, when a sheet whose sheet length is too long, an automatic double-sided mode cannot be executed.
If the number of conveying rollers on a conveying path is increased to make distances between them short, or an inversion path is configured to be long in order to solve the problems described above, this will increase the cost and size of an image forming apparatus. In view of the circumstances, in many conventional models, an automatic double-sided mode is disabled in a non-specified size mode in which a sheet is fed from a manual feed tray with a sheet length in a conveying direction undermined.
However, even in a case where a sheet placed on a manual feed tray is a general regular-size sheet such as an A4- or B4-size sheet when image formation is to be performed in the non-specified size mode, usability will be significantly compromised if an automatic double-sided mode is disabled across the board. Moreover, in a case where a double-sided mode is enabled in the non-specified size mode in the apparatus described in Japanese Laid-Open Patent Publication (Kokai) No. H07-330228, when it is determined that a sheet has such a length that the sheet cannot be conveyed, there is no other choice but to dealt with this as a sheet jam, causing an increase in downtime of the image forming apparatus.

Image forming apparatus capable of forming images in double-sided mode


An internal retractor has a clamp, a retractor hook and a universal joint therebetween. The internal retractor has a transverse dimension insertable through a cannula, and a longitudinal dimension deployable to retract user selectable organs. The internal retractor may be elongable. The internal retractor clamp may be closed in its rest position. The internal retractor clamp may be atraumatic. The internal retractor hook may be traumatic.

1. Field of the Invention
The field of the present invention is in medical surgeries, laparoscopic and minimally invasive endoscopic surgeries in particular.
2. Related Art
Most surgeries require retraction of various tissues and organs during the course of the surgery in order to properly expose the organ needing treatment and surgical repair. Traditional surgery with a large working space provided by a large entry incision allowed physicians or their assistants to reach into the surgical field with large retractor instruments and secure the subject organ or tissue and hold it securely out of the surgeon's way as he or she proceeds to the organ requiring surgical treatment.
In recent years, the advantages of laparoscopic surgery have made such minimally invasive procedures more and more common. In particular, single incision laparoscopic surgeries ("SILS") have been increasing due to both the cosmetic and therapeutic advantages of creating only one incision. The corresponding disadvantage of single incision laparoscopic surgeries in particular and laparoscopic surgeries in general is the reduced access of the surgeon and medical personnel to the surgical field and the consequent difficulty in executing otherwise routine surgical steps such as retraction. An example of a surgery highlighting these issues is single incision laparoscopic sleeve gastrectomy.
One of the operative requirements for all instruments being used in laparoscopic surgery in general and single incision laparoscopic surgery in particular is that the instruments and tools fit through a cannula which is in lay terms the long tube through which the surgeon enters the surgical space, frequently the abdomen, and through which tools are inserted and work is done. This operative requirement means that prior art normal retraction tools such as clamps or hooks cannot be used because they would occupy the space in the cannula that is needed for surgical tools such as pinchers, graspers, forceps, scalpels and energy devices. The prior art solution has been to make a second incision through which required instruments like retractors may be inserted in place. Therefore, in order to avoid a second incision, a retractor is needed that may be inserted through a cannula placed to achieve its useful purpose, and then maintain retraction entirely independently and entirely within the patient's body.
Prior art attempts to meet these needs have resulted in instruments that are cumbersome, complex and have a limited range of useful applications. For some procedures, such as single incision laparoscopic sleeve gastrectomies, previously developed instrumentation tools and retractors are not effective for the particular needs of that surgery, for example, retracting the left lobe of the liver in order to properly expose the stomach for the procedure at hand. Finally, time is always at a premium during surgery. Promoting speed without sacrificing accuracy or proper tissue handling is always advantageous. Hence, a device requiring fewer steps for execution of its use is advantageous.

THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS


A device for obtaining an image includes a projector configured to project light having a preset pattern to an object, a first camera configured to sense light reflected and fed back by the object to obtain a depth image, a second camera configured to obtain a color image of the object, a motion sensor configured to sense a motion of the device. The device also includes and a processor configured to obtain a color image and a plurality of depth images of the object, by changing a parameter about the projected light and the light sensed by the first camera. When the motion of the device is less than a threshold, the processor is configured to merge pieces of depth information respectively obtained from the plurality of depth images with each other, and obtain a 3D image of the object, based on the merged depth information and the color image.

With information technology (IT) development, devices recognize an operation of a user or movement of an object, interpret the recognized operation or movement as an input signal, and operate in correspondence with the input signal. Accordingly, devices have to extract three-dimensional (3D) information about the operation of the user or the movement of the object by using a camera.
When the devices are controlled, the necessity for depth information, which is 3D information, increases, and research into various techniques for extracting 3D information has recently been actively conducted. For example, a technique of projecting light having a specific pattern to an object and sensing a variation in the pattern of light reflected and fed back by the object to thereby obtain depth information of the object is being developed. However, compared with color images, the depth information still has low resolution, leading to degradation of the quality of 3D images.

Method and device for obtaining image, and recording medium thereof


A method of production of a multilayer circuit board comprised of a multilayer structure circuit formed by a plurality of interconnect layers and insulation layers stacked together and a semiconductor chip included therein, including the steps of placing a semiconductor chip having a polished back surface, with its active surface facing downward, on an already formed lower interconnect layer and forming an insulation layer over the layer on which the semiconductor chip has been placed, the method further including the step of treating the polished back surface of the semiconductor chip to improve its bondability with the insulation layer before the step for formation of the insulation layer.

1. Field of the Invention
The present invention relates to a method of production of a multilayer circuit board comprised of a multilayer structure circuit formed by a plurality of interconnect layers and insulation layers stacked together and a semiconductor chip included therein.
2. Description of the Related Art
Multilayer circuit boards with built-in semiconductor chips are being widely used as thin boards. The built-in semiconductor chips have to be made as thin as possible in order for them to fit in the limited board thickness. As means for this, the practice has been to polish the back surfaces so as to reduce the thickness of the semiconductor chips (for example, see US 2001/0008794A1, [00103] to [0110]). Such a semiconductor chip polished on its back surface, however, creates the following problem in the process of production of a multilayer circuit board.
That is, when placing the semiconductor chip to be built in, with its active surface facing down, on a lower interconnect layer and then forming an insulating film over it, sometimes the smoothly polished back surface will have insufficient bondability with the insulating film laid over it. As a result, when performing reflow as part of the process of production of the multilayer circuit board or running an environment test as a test of the finished multilayer circuit board, the problem has arisen of the insulating film ending up being peeled off from the semiconductor chip due to the shrinkage stress of the resin.

Method of production of multilayer circuit board with built-in semiconductor chip


To provide a system and its method for receiving inquiries for personal histories or performing certification of histories collectively.

1. Field of the Invention
The present invention relates to a system and method for certifying histories for personal use, and more particularly, to a certificate issuing system and method for certifying, for example, lifelong histories of learning, activities and skills necessary for social activities such as attending schools and finding jobs.
2. Description of the Related Art
Presently, increasing numbers of individuals obtain qualifications to enhance their capabilities. There are many qualifications that are socially useful. For individuals to prove the qualifications, certificates must be granted from the organizations authorizing the respective qualifications to prove the possession of the qualifications. Thus, the absence of a collective certifier causes many complications and obscurities.
Moreover, in this day and age of lifelong learning, it is desirable that a passport that certifies what has been learned in one's life be issued.
In addition, the number of people who participate in volunteer activities is on the increase. Growing numbers of volunteers wish to have their activity hours accredited by various volunteer activity implementation organizations such that they can enjoy treatments associated with the accredited volunteer hours in the future.

Authentication history certification system and method thereof

Abstract: The present invention provides an authentication history certification system for certifying a personal history on a computer system, including a history acquisition means (122) for acquiring and recording histories, a history verification means (123) for making a history inquiry or verification with an organization authorizing the history to verify whether or not a personal history is authentic, a history extraction means (124) for extracting and displaying a history, and a history certification means (125) for certifying a personal history defined by a history extracted from history data recorded and managed.

Kabushiki Kaisha Nihon Toukei Jim Center


A vehicle parking structure particularly well adapted for providing a parking capacity of up to about 20 vehicles has a structure framework with an entrance/exit level and a plurality of parking level floors, each of the floors having a pair of parking bays located on opposite sides of an elevator shaft. Vehicles to be parked are driven onto a vehicle tray, which is raised and lowered by means of an elevator in the elevator shaft. The elevator includes a shifter on which the tray is supported which allows the tray to be cantilevered outwardly from the elevator at a parking level. With the tray so cantilevered outwardly, the tray is incrementally lowered to rest on a pair of tray supports in the desired parking bay. The shifter is then retracted and the elevator can be raised or lowered to another level as required. To retrieve a vehicle, the elevator and shifter is positioned incrementally below the identified tray, and the shifter is extended into the bay. Raising the elevator incrementally lifts the tray from the parking bay such that it is supported by the shifter, which can then be retracted with the tray. The elevator is then raised or lowered as required. Operation of the elevator drive and the shifter may preferably be carried out under the control of a microprocessor control system.

U.S. Pat. No. 3,497,087 to one of the present inventors discloses an automatic vehicle parting system intended to provide a tiered parking structure the dense parking of parked vehicles. Such a construction contemplated significant economies in both site utilization and operation, providing parking for a plurality of vehicles upon a relatively limited land space area. In that inventor""s subsequent U.S. Pat. No. 5,980,185, an improved automated parking garage structure is disclosed utilizing a rectilinear, rather than cylindrical structure.
The foregoing and other parking systems are of significant utility, as they each allow significant utilization of limited land space, allowing vehicles to be parked and stacked in a vertical-extending array. In general, such constructions are more efficient than conventional non-mechanized parking garage structures, where access is obtained through ramps sloping through the structure, the vehicles being driven, rather than carried, to a parking location.
Yet even these automated structures require a relatively large plot of land and are of a complex and expensive construction. While the number of vehicles which may be parked therein is large, the economies of scale require a large investment. Often there is a need for a parking structure of more limited capabilities. The land available may be impractical or insufficient for the construction of a parking structure having a large number of parking spaces on a given level, requiring expensive and complicated shuttle means to both raise the vehicle to the level and to direct the vehicle horizontally into a chosen one of a relatively large plurality of stalls. Alternatively, sufficient funds may be unavailable for a large structure, or the parking requirements for the location may be more modest.
It is accordingly a purpose of the present invention to provide an automated vehicle parking/storage facility capable of being constructed and operated on relatively small land areas.
Yet a further purpose of the present invention is to provide such a storage structure which is of economical construction and efficient operation.
Another purpose of the present invention is to provide a parking structure of the aforementioned general format which does not require driver assistance for vehicle parking or retrieval.
In accordance with the foregoing and other objects and purposes, a vehicle parking structure in accordance with the present invention comprises a structure having a central vertical elevator shaft having elevator means for raising an unoccupied vehicle to be parked or stored from an entrance level location to a chosen parking stage level or story and depositing the vehicle in an empty stall at the level, as well as for retrieving a parked vehicle from a stall and returning it to the entrance level location for departure from the structure. Each parking story comprises parking space for two vehicles, one space on each of opposite sides of the elevator shaft.
A vehicle to be parked is driven onto a tray on the elevator at the entrance level. The tray sits upon a shifter means that includes an extension mechanism which allows the tray to be extended and held outwardly of the elevator shaft in one of two opposite directions when the elevator is raised to the level of the intended vacant stall, to position the tray within the intended stall and lower the tray and vehicle onto supports in the stall. The extension mechanism then retracts and returns to a central, neutral position within the elevator shaft. The elevator can then be directed either to the entrance level to accommodate a new vehicle to be stored or to a parking level to retrieve a parked vehicle.
A parked vehicle is retrieved by positioning the elevator such that shifter is slightly below the level of the tray on which the vehicle is located, extending the extension mechanism to align with the vehicle, raising the elevator to lift the tray and vehicle from the supports and retracting the extension mechanism to the neutral position within the shaft The parked vehicle is then lowered to the entrance level stage for drive off.
An interlock system is provided to maintain a tray on the supports of a parking stall. The interlock is disengaged when the shifter deposits or removes a tray from the supports. Such as interlock is of significant value, particularly in high wind areas, since unoccupied trays are stored in the stalls and can be subject to large wind-induced forces. The shifting apparatus is of unique and simplified construction, allowing for efficient operation. A garage utilizing the elevator and shifter may be adapted to varying heights and parking levels, in accordance with the numbers of vehicles to be stored.


Embodiments of the present invention disclose a capacitive in-cell touch panel and a display device, with a touch sensing structure layer disposed on a side of an opposite substrate opposite to an array substrate, which side faces a liquid crystal layer; the touch sensing structure layer comprises a first touch sensing electrode and a second touch sensing electrode that are disposed in a same layer and mutually insulated; one of the first touch sensing electrode and the second touch sensing electrode is configured to be loaded with touch control scanning signals, and the other of the first touch sensing electrode and the second touch sensing electrode is configured to couple the touch control scanning signals and output. The touch sensing structure layer is provided on the opposite substrate that is away from the array substrate, which can avoid the mutual interference between touch control signals and display signals in the array substrate.

With the rapid development of display technology, touch screen panels have been gradually spreading throughout people's life. Nowadays, touch screen panels, according to configurations, can be classified into: add-on mode touch panels, on-cell touch panels, and in-cell touch panels. An add-on mode touch panel is a liquid crystal display having a touch function and is formed by producing a touch screen panel and a liquid crystal display (LCD) separately and then attaching them together. An add-on mode touch panel has disadvantages such as higher manufacturing costs, lower light transmittance, thicker module, and so on. An in-cell touch panel has touch control electrodes for a touch screen panel embedded inside a liquid crystal display, can decrease the whole thickness of the module, can have significantly reduced manufacturing costs for the touch screen panel, and thus become attractive to main manufacturers.
At present, a capacitive in-cell touch panel is realized by directly adding touch control scanning lines and touch control sensing lines on a current TFT (thin film transistor) array substrate, that is, on a surface of the TFT array substrate, manufacturing two layers of stripe-like electrodes that are non-coplanar but intersect with each other. These two layers of electrodes respectively serve as touch control driving lines and touch control sensing lines of the touch screen panel, and at a non-coplanar intersection between two of the electrodes, there forms a mutual capacitor. The working process of the capacitive in-cell touch panel is that: when the electrodes serving as touch control driving lines are loaded with touch control driving signals, the voltage signals coupled out by the touch control sensing lines via the mutual capacitor are detected, and during this process, when a human body contacts the touch screen panel, the electric field of the human body will act on the mutual capacitor, making the capacitance value of the mutual capacitor change and then changing the voltage signals coupled out by the touch control sensing lines, and the contact positions can be determined according to changes of the voltage signals.
In the configuration design of the abovementioned capacitive in-cell touch panel, the touch control signals, loaded over the touch control scanning lines and the touch control sensing lines that are added on the current TFT array substrate, will mutually interfere with the original display signals in the TFT array substrate, which not only has an influence on the quality of liquid crystal display pictures but also deteriorates the reliability of touch control operations.

Capacitive in-cell touch panel and display device

CHENGDU BOE OPTOELECTRONICS TECHNOLOGY CO., LTD.


A device and method for recovering data in a file system. The method includes the steps of performing a given function that effects a change in a control structure of the file system and concurrently saving data relevant to the function in a state as data for a recovery, and recovering the interrupted function by using the data saved for a recovery, to prevent the loss of file data and maintain the consistency of the file system. The device includes a flash memory to store the control structure.

1. Field of the Invention
The present invention relates to a file system characterized by a control structure such as a file allocation table and a directory tree and, more particularly, to a device and method for recovering data in a file system when the computer on which the file system is maintained is restarted due to errors. Specific examples presented herein apply particularly to file systems characterized by file allocation tables. However, persons of skill in the computer arts will understand that the present invention encompasses data recovery in a wide variety of modern computer systems and file systems used therein.
2. Description of the Related Art
A file allocation table (FAT) and associated directories are used for the convenience of users of a computer system, such as a communications switching system (i.e., a PBX or keyphone system), that employs a file management system to manage large-capacity files. When a fatal error occurs in the course of processing files, the computer system must be restarted by means of a software or hardware operation (by pressing a power-on switch twice or pressing a reset button, for example). A restart operation that occurs when the FAT or a directory is being changed may lead to an anomalous situation: the data processed before the restart operation remains available, but consistency is not assured for the data related to the FAT or the directory being changed.
When the computer system is restarted, the file system may fall out of consistency with respect to the storage state of management information maintained for controlling the overall file system. This inconsistency may result in the loss of file data and, most undesirably, in an interruption of services of the computer system. Such an interruption may amount to only an inconvenience in some situations involving only general personal computers. However, it presents a major problem for mission-critical systems and particularly for switching systems that are required to provide continuous service with high reliability. System reliability is substantially reduced if service may be suspended after a restart operation due to the loss of essential programs and data required for system operation.
The critical problem of recovering file system control structure data upon restarting the system has generated three general types of solutions. U.S. Pat. No. 5,561,795 provides an example of the first type, wherein the file system maintains an ongoing log of file system transactions. This approach has seen success in a variety of contexts, but it has the drawback that with large file systems a long and complex procedure may be required to reconstruct the file system control structure. An even more serious limitation is that transaction logging may not ensure recoverability of corrupted control structure data. Both of these features make transaction logging of only limited usefulness for data recovery in mission-critical systems such as switching systems.
A second approach to data recovery is exemplified by U.S. Pat. No. 5,504,883, entitled "METHOD AND APPARATUS FOR INSURING RECOVERY OF FILE CONTROL INFORMATION FOR SECONDARY STORAGE SYSTEMS" and issued Apr. 2, 1996 to Coverston et al., the disclosure of which is incorporated herein by reference. Here a pair of disk drives is used to back up control information from cache memory on a periodic basis. Each of the disk drives writes a time control stamp immediately before and after writing the current control structure to disk. If the system is restarted, the recovery system compares the four control stamps (one before and one after the copy of the control structure on each of the disks) to identify an intact copy of the control structure. Two storage devices are needed in this approach to ensure that an intact copy of the control structure remains in storage even while the file system is updating the other copy.
The elegant solution provided by the '883 patent has certain features that unfortunately limit its usefulness for mission-critical, high performance systems such as switching systems. First, it requires redundant disk storage devices that increase the overall cost of the computer system in which it is implemented. Such storage devices, even with modem designs, have relatively slow access times and require a separate controller to control the interface between the storage device and the rest of the computer system. More seriously, recovery of control structure data from backup files entails an inherent performance tradeoff: more frequent backups drive up the system's management overhead, and fewer backups risk catastrophic data loss. Such compromises are desirably avoided in application environments that require both high reliability and high performance.
The use of flash memories (or FEPROMs) has been suggested as a way to avoid the disadvantages of dual mass storage devices while retaining the benefits of redundant storage of critical data. For example, U.S. Pat. No. 5,432,927, entitled "FAIL-SAFE EEPROM BASED REWRITABLE BOOT SYSTEM," issued Jul. 11, 1995 to Grote et al., the disclosure of which is incorporated herein by reference, shows a boot sequence reprogramming system using dual flash memories. Flash memory is a recently-developed EEPROM technology suitable for an expanded range of applications because it allows numerous rewrites. The '927 patent shows a successful application for redundant storage of an effective boot sequence routine while an updated boot sequence routine is loaded.
On the other hand, writing to a flash memory still requires elevated voltages, as with traditional EEPROM devices, and the design complications that those elevated voltages entail. Moreover, U.S. Pat. No. 5,392,427, entitled "SYSTEM FOR UPDATING DATA STORED ON A FLASH-ERASABLE, PROGRAMMABLE, READ-ONLY MEMORY (FEPROM) BASED UPON PREDETERMINED BIT VALUE OF INDICTING POINTERS" and issued Feb. 21, 1995 to Barrett et al., the disclosure of which is incorporated herein by reference, illustrates some of the complications that arise when using flash memories for frequently-updated data storage. Most seriously, mere replacement of mass storage devices with flash memory devices will not avoid the overhead-data loss tradeoff problem inherent to redundancy systems.
A third, promising approach to data recovery was proposed in U.S. Pat. No. 4,164,017, issued Aug. 7, 1979 to Randell et al. The disclosed apparatus runs a program that is divided into program blocks. Data that will be changed by the execution of a given block is backed up in memory prior to execution of the block. The basic idea of process segmentation provides a potential alternative to data recovery through storage redundancy, but the '017 patent does not explain how that idea might be implemented to overcome the problems associated with reliable recovery of file allocation data. In particular, it does not show how to restore a file control structure to consistency when consistency has been lost due to the occurrence of a restart event while the file control structure was being modified.
The '017 patent also does not show how process segmentation might be used with advanced semiconductor devices to overcome the problems of control structure data recovery. Indeed, much of the currently available semiconductor technology, including flash memories and high-capacity (1 Mb or higher) SRAMs, did not exist when the '017 patent was granted. See generally Betty Prince, SEMICONDUCTOR MEMORIES: A HANDBOOK OF DESIGN, MANUFACTURE, AND APPLICATION (2d ed. 1991), the disclosure of which is incorporated herein by reference. Specific attention is directed to pages 537 and 398-90 of this reference.
An application of the idea presented in the '017 patent has been proposed in U.S. Pat. No. 5,564,011, entitled "SYSTEM AND METHOD FOR MAINTAINING FILE DATA ACCESS IN CASE OF DYNAMIC CRITICAL SECTOR FAILURE" and issued Oct. 8, 1996 to Yammine et al., the disclosure of which is incorporated herein by reference. This system protects against data loss from failure of certain critical disk sectors, which contain file management data, by storing enough information in main memory to allow at least partial recreation of the critical sector data. If the file system detects that a critical sector has failed, it can create at least a partial image of the sector in memory from data read at initialization and at updates.
The ability to recover the control structure state that existed just prior to the occurrence of an error would effectively address the overhead-data loss tradeoff problem of redundancy systems. But the system of the '011 patent unfortunately may only provide partial recovery of the data stored in an affected disk sector. Also, the disclosed system relies upon data stored in main memory to perform this recovery, and this data would be lost if power to the computer system failed. Redundancy systems at least provide the assurance that a usable data structure can be recovered. Data regeneration as provided by this patent therefore would not adequately address the data recovery needs that exist for file systems required to provide high performance and high reliability.
We have found, in fact, that a need exists for an efficient and reliable alternative to redundancy-based data recovery systems. Such an alternative would avoid the overhead and reliability drawbacks of redundancy systems. It should also reliably allow recovery of data after any of the full range of possible error conditions, including total interruptions of power to the computer system. Desirably, it would enable recovery of a faithful copy of the system's control structure as it existed just prior to the condition that necessitated restarting the system. Ideally, its data safekeeping operations would add only modestly to the operational overhead of the file system.

Device and method for data recovery in a file system


A switching circuit includes: a detection wiring configured to receive a potential changing depending on a current of a first switching element; a first circuit connected between the detection wiring and a first having a first time constant, and making the first wiring follow the potential of the detection wiring; a second circuit connected between the detection wiring and a second wiring, having a second time constant larger than the first time constant, and making the second wiring fellow the potential of the detection wiring; a potential maintaining circuit configured to maintain the second wiring at a potential higher than the potential of the first wiring while a current is not flow through the first switching element; and a control circuit configured to turn off the first switching element in a case where the potential of the first wiring exceeds the potential of the second wiring.

A switching circuit has been known that controls a current by switching a switching element. There may be a case where an overcurrent flows through the switching element due to a short-circuit of another element connected to the switching element, or the like. In a case where the overcurrent flows, it is necessary to turn off the switching element as soon as possible to protect the switching element. In one of control methods for protecting the switching element from the overcurrent, the switching element is configured to be turned off when the current flowing through the switching element exceeds a threshold value. However, according to this control method, when the current increases rapidly (i.e., when an increasing rate of the current is extremely high), the current may increase to a still higher value during a period from when the current exceeds the threshold value until when the switching element is turned off, as a result of which the switching element cannot be protected appropriately.
On the other hand, Japanese Patent Application Publication No. 2017-22830 discloses a switching circuit that is configured to turn off a switching element when an increasing rate of the current flowing through the switching element exceeds a threshold value. In this switching circuit, the increasing rate of the current flowing through the switching element is detected by using a parasitic inductance of a wiring to which the switching element is connected. When the increasing rate of the current exceeds the threshold value, the switching element is turned off. In this control method, the switching element is turned off based on the increasing rate of the current before the current flowing through the switching element increases to a high value. Due to this, the switching element can be protected suitably from the overcurrent.


A diversity antenna comprising two planar inverted F antennas (PIFAs) characterized by: two radiating elements with or without the physical separation between them; the spatially separable radiating elements of the two PIFAs with side-by-side or orthogonal placement with respect to each other are combined to form an equivalent single element consisting of the composite assembly of two radiators; a small ground plane of rectangular or L-shape with or without bending at its opposite ends is common to both the radiating elements; the radiating elements are placed above the unbent common ground plane; the radiating elements are placed above the vertical sections of the bent common ground plane; the shorted ends of the spatially separated radiating elements are placed back to back on the said common ground plane; a common shorting post placed along the common boundary line resulted by the merging of the two radiators with a prior side by side mutual placement; a common shorting post placed within the common boundary surface resulted by the merging of the two radiators with a prior mutual orthogonal orientation.

1. Field of the Invention
This invention relates to a diversity antenna system which includes two planar inverted F antennas which have a small common ground plane. Four embodiments of the invention are disclosed herein.
2. Description of the Related Art
In its simplest form, the diversity technique, as it applies to antennas for RF data and wireless communication devices, provides a means of achieving reliable and enhanced system performance through the use of an additional antenna. A diversity antenna system utilizes two antennas which sample the RF signal to determine the strongest signal to enable the communication device to utilize the strongest RF signal. To meet the requirement of sustained and fast rate of data transfer, specific emphasis has been recently placed on diversity antennas in RF data communication. Despite the enhanced reliability and the improved performance of an antenna system with the diversity scheme, its adoption to a compact wireless system is not widespread. Theoretically, the spatial diversity technique requires a physical separation of one wavelength between the two antennas. In many practical applications, it may not be feasible to provide the required separation between the two antennas of a spatial diversity scheme. The requirement of a wide separation between the two antennas of a diversity scheme also requires a longer feed cable to the individual antennas from a common RF source point. The resulting longer feed cable leads to the problem of ensuring effective shielding of the cable, the consequent RF power loss in the cable and the undesirable interference effect on system performance particularly at a higher frequency band. The above-mentioned shortcomings apply to diversity schemes consisting of conventional external antennas which have been in existence for a long time as well as with the recently evolving internal antenna. In view of the above constraints associated with the conventional diversity scheme, emphasis is being shifted to arrive at a compactness of the overall spatial diversity scheme which meets acceptable performance standards.
Of late there has been an increasing emphasis on internal antennas instead of a conventional external wire antenna. The concept of internal antenna stems from the avoidance of a protruding external radiating element by the integration of the antenna into the device itself. Internal antennas have several advantageous features such as being less prone for external damage, a reduction in overall size of the handset with optimization, and easy portability. The printed circuit board of the communication device serves as the ground plane of the internal antenna. Among the various choices for internal antennas, the PIFA appears to have great promise. The PIFA is characterized by many distinguishing properties such as relative lightweight, ease of adaptation and integration into the device chassis, moderate range of bandwidth, Omni directional radiation patterns in orthogonal principal planes for vertical polarization, versatility for optimization, and multiple potential approaches for size reduction. Its sensitivity to both vertical and horizontal polarization is of immense practical importance in mobile cellular/RF data communication applications because of the absence of the fixed antenna orientation as well as the multi-path propagation conditions. All these features render the PIFA to be a good choice as an internal antenna for mobile cellular/RF data communication applications.
The PIFA also finds useful applications in diversity schemes. Despite all of the desirable properties of a PIFA, the PIFA has the limitation of a rather large physical size for practical application. A conventional PIFA should have the semi-perimeter (sum of the length and the width) of its radiating element equal to one-quarter of a wavelength at the desired frequency. With the rapidly advancing size miniaturization of the radio communication devices, the space requirement of a conventional PIFA is a severe limitation for its practical utility. Further, the internal antenna technology is relatively new and is in an evolving stage of development. The combination of inherent shortcomings associated with the size of the PIFA and the requirement of even larger space or volume for multiple PIFAs seems to be the primary reason for the non-feasibility of the use of PIFA for diversity schemes of modern wireless communication systems.
To assist in the understanding of a conventional PIFA, a conventional single band PIFA assembly is illustrated in FIGS. 9A and 9B. The PIFA 110 shown in FIG. 9A and FIG. 9B consists of a radiating element 101, a ground plane 102, a connector feed pin 104a, and a conductive post or pin 107. A power feed hole 103 is located corresponding to the radiating element 101. The connector feed pin 104a serves as a feed path for radio frequency (RF) power to the radiating element 101. The connector feed pin 104a is inserted through the feed hole 103 from the bottom surface of the ground plane 102. The connector feed pin 104a is electrically insulated from the ground plane 102 where the pin passes through the hole in the ground plane 102. The connector feed pin 104a is electrically connected to the radiating element 101 at 105a with solder and the body of the feed connector 104b is electrically connected to the ground plane at 105b with solder. The connector feed pin 104a is electrically insulated from the body of the feed connector 104b. A through hole 106 is located corresponding to the radiating element 101, with the conductive post or pin 107 being inserted through the hole 106. The conductive post 107 serves as a short circuit between the radiating element 101 and the ground plane 102, The conductive post 107 is electrically connected to the radiating element 101 at 108a with solder. The conductive post 107 is also electrically connected to the ground plane 102 at 108b with solder. The resonant frequency of the PIFA 110 is determined by the length (L) and width (W) of the radiating element 101 and is slightly affected by the locations of the feed pin 104a and the shorting pin 107. The impedance match of the PIFA 110 is achieved by adjusting the diameter of the connector feed pin 104a, by adjusting the diameter of the conductive shorting post 107, and by adjusting the separation distance between the connector feed pin 104a and the conductive shorting post 107.
In this invention, several new embodiments of compact diversity PIFAs having a small and common ground plane are disclosed. This invention demonstrates that it is possible to retain the performance of individual antennas of a spatial diversity antenna scheme even when the separation between the antennas is only a fraction of a wavelength. In the first embodiment of this invention, two PIFAs are placed back to back on a small rectangular ground plane. The two PIFAs are placed such that the shorted ends of the PIFAs face each other. Such an arrangement ensures better isolation between the two PIFAs despite being placed in close proximity to one another. In the second embodiment of this invention, the ground plane is bent at its opposite ends to form vertical sections. The two PIFAs are placed (outward) on the vertical sections at the opposite ends of the ground plane. Such an arrangement of PIFAs allows the placement of some system components between the two vertical sections of the bent ground plane. The distortion of the radiation patterns of the PIFAs is also minimized despite the presence of some components between the two PIFAs. This is mainly due to the blockage effect offered by the vertical sections of the ground plane. With a significantly different design configuration, in the third embodiment of this invention, there is no physical separation between the two PIFAs placed on a common rectangular ground plane. Only a single shorting pin or post partitions the two diversity PIFAs resulting in an extremely simple and compact diversity PIFA. The virtual electrical partitioning between the two radiating elements is realized through the common shorting post. The virtual electrical partitioning between the two radiating elements in lieu of the proposed choice of placement of the shorting post overcomes the need for physical separation between the two radiating elements to serve as separate antennas of a diversity scheme. In the fourth embodiment, which is a modification of th e third embodiment, the two PIFAs, which are not physically separated, are placed on a common L-shaped ground plane. The partitioning of the two antennas is again realized through a common shorting post. Unlike the third embodiment, the two PIFAs of the fourth embodiment are oriented orthogonal to each other. The basic concepts proposed in all the embodiments of this invention have been proved through the design of diversity PIFAs for ISM Band applications. In all of the above-described embodiments, good VSWR performance is achieved. The individual PIFAs of the embodiments show satisfactory gain performance. The invention disclosed herein can be extended to other frequency bands of interest.
One of the principal objects of the invention is to circumvent the requirement of wide separation between the two internal PIFAs of a spatial diversity scheme.
A further object of the invention is to provide an efficient design of a diversity antenna utilizing only a small ground plane that is common for both the antennas.
Still another object of the invention is to provide a compact diversity PIFA characterized with the salient feature of the absence of physical partitioning between the two antennas.
Yet another object of the invention is to utilize the common ground plane of non-rectangular shapes in diversity PIFAs.
Another object of the invention is to design individual PIFAs of a diversity antenna which are compact in size.
Still another object of the invention is to provide diversity PIFAs having the desirable features of configuration simplicity, compact size, cost effective to manufacture and ease of fabrication.
These and other objects will be apparent to those skilled in the art.

Diversity antenna system including two planar inverted F antennas


In a disk player in that switching between chucking a disk-like recording medium to a turntable and canceling the chucking is performed with forward movement and backward movement of a slider, the slider is maintained stable at an initial position and a forward movement position. A rack member is arranged so as to overlap the slider bottom; a lever is provided so as to have an engaging pin engaging with an engaging hole of the slider and with an engaging hole of the rack member; and moreover, the engaging hole of the rack member includes a first recess and a second recess, so that without an external force applied to the slider, the position of the slider is stably maintained with the engaging pin of the lever at the forward movement position and the initial position.

1. Field of the Invention
The present invention relates to a chucking device for a disk player and a disk player, and in particular relates to a chucking device for a disk player capable of chucking operation and canceling the chucking operation in operative association with the forward and back movement of a slidable slider and a disk player having such a chucking device.
2. Description of the Related Art
In general, in a disk player for recording and/or reproducing using a disk recording medium such as a compact disk, in a state that the disk is introduced on a turntable, the disk is pushed on the turntable with a chucking member, and while the disk is driven by the turntable, an optical pick-up is radially moved, thereby writing or reading out a signal.
Therefore, in the disk player, the chucking member must be moved in the chucking direction in synchronous with the insertion of the disk. Then, the disk player has been conventionally provided with a slider which is driven by a motor via a rack/pinion mechanism, thereby switching the chucking operation. The slider is stretched by a tension coil spring in the retracting direction to an initial position. Alternatively, during retraction, with a helical torsion coil spring, the slider is urged in the retracting direction while during progressing, the slider is flicked by an elastic snapping force in the progressing direction.
In such a manner, according to the structure in that the slider for switching the chucking operation is stretched in the retracting direction by the tension coil spring or flicked in the retracting and progressing directions by the helical torsion coil spring, a peak load of slider driving is generated in an unnecessary portion, reducing the operational stability by the additional load. Also, at the moment when the slider is released from the driving, the slider is backward moved to the standby position by the force of the spring, so that noise is produced at this time.
Also, in the conventional backward movement system by the spring, if a driving gear is rotated in the following operation, the slider may be mated with the gear, so that the stability of chucking starting operation may be decreased; a user is unnecessarily disturbed; or operational noise may be produced, causing to deteriorate a commercial value of the disk player.

Chucking device for disk player and disk player


Water filter module for filtration of water used to brew coffee, having a series of vertically aligned filters placed in a body member and having a charcoal filtration member bounded by screen at its upper and lower ends and in the water filter module.

1. Field of the Invention
The present invention pertains to a filter system, and more particularly, pertains to a water filtration system for filtering of water used in the brewing of coffee through a series of filtration devices, one of which is a layer of carbon granules.
2. Description of the Prior Art
Traditional coffee making systems have incorporated elaborate systems for the brewing of coffee and to extract the most desirable brew of coffee, only to have these efforts thwarted by using tap water, the likes of which imparts the taste of impurities contained in the brewing water to the brewed coffee, such to the dislike of the consumer. Most municipalities use chlorine to treat and disinfect their water supply. Chlorine reacts adversely with the water leaving it with a chlorine taste and odor. As a chemical the free chlorine reacts with the coffee grinds to adversely affect the taste of brewed coffee.
The present invention provides a filtration system for removing undesirable impurities found in the water used to brew coffee. The filter module removes residual chlorine, odors, foul tastes, impurities and any other sediments found in a water supply prior to the water coming in contact with the coffee grinds. The present invention is used with drip type coffee makers. Hot water drips into the water filter module, which sits upon the coffee grinds in the coffee grind basket. Water is filtered through the granules of carbon and mesh screens and then exits from the bottom of the invention entering into the coffee grinds. The filter module can also be used for filtration of water for use in tea or other consumable liquids.


A dispenser for dispensing particulate cleaning material onto a floor surface includes a hopper holding the particulate material and having a dispensing aperture defined by a part that is movable with respect to the hopper itself. This moving part also imparts movement toward the dispensing aperture of particulate cleaning material in the hopper. The dispenser may be attached to a floor cleaning apparatus and includes a biasing device that that biases the movable part into a position which closes the dispensing aperture when the dispenser is removed from the floor cleaning apparatus.

Floor coverings such as carpets and rugs are prone to marks and stains. Floor coverings can be cleaned in a number of ways, which can be classified as 'wet' or 'dry' cleaning methods. Wet cleaning methods such as washing or shampooing the floor covering have the disadvantage that they can cause shrinkage of the floor covering. Dry cleaning generally involves depositing a powdered composition onto the floor covering which can readily absorb soil and contaminants from the floor covering. The powder is worked into the floor covering with the aid of a brush. Finally the dirty powder can then be removed from the floor covering by a vacuum cleaner. While such compositions are called 'dry', in that they flow as a powder at room temperature, they usually contain a quantity of liquid such as water or organic solvents.
The cleaning powder needs to be dispensed on to the floor covering. U.S. Pat. No. 4,268,935 and U.S. Pat. No. 5,101,532 describe powder-dispensing machines for use in cleaning carpets. In U.S. Pat. No. 5,101,532, a dispensing hopper is integrally formed as part of the machine for storing and dispensing dry-cleaning powder. At the front, lower part of the hopper there is a jaw which is formed by a lower flap which is hingedly fixed to the hopper. In use, the flap is oscillated about a mean gap width of around 4 mm so as to dispense powder onto the floor surface. The position of the lower flap is controlled by a user-operated control which moves the flap between one of two fixed positions: a dispense position, in which the flap is set to the 4 mm gap, and a grooming and vacuuming position in which the flap seals the hopper to prevent any powder escaping from the hopper. In use, the machine dispenses powder onto the floor surface at a controlled rate.
In the dispenser of U.S. Pat. No. 4,268,935 a powder dispenser is attachable to a vacuum cleaner. The dispenser has a hopper within which a metering drum is rotatably mounted to regulate the flow of powder from the hopper. A closure member is mounted within the hopper, downstream of the metering drum and just upstream of the discharge outlet. The closure member is manually operable between an open position in which powder may fall from the metering drum to the discharge outlet and a closed position in which the outlet is blocked.
A removable dispenser is convenient in that it only needs to be mounted on the cleaner when it is required. During normal cleaning the dispenser can be removed and stored without cluttering the cleaner. However, the use of a removable dispenser can cause some handling problems for inexperienced users. A user may not require all of the powder that they have poured into the dispenser with the result that the dispenser may still be partially filled with powder when it needs to be removed from the cleaner. Without careful handling there is a likelihood that powder will be spilled on to the floor surface. This results in dissatisfaction for a user.

This patent is subject to a terminal disclaimer.

Floor cleaning apparatus including self-closing dispenser for dispensing particulate cleaning material