A system and method for removing impulsive noise from a digital signal are disclosed. The system and method determines either a neighborhood maximum and/or a neighborhood minimum for a pixel of interest. The intensity of the pixel of interest is then compared to the neighborhood maximum or the neighborhood minimum to determine whether the pixel of interest should be replaced.

Digital video products and services and devices for storage and retrieval of video streams on the Internet are ubiquitous in the marketplace. Due to limitations in digital signal storage capacity and limitations in network and broadcast bandwidth, compression of digital video signals is essential to digital video storage and transmission. As a result, many standards for compression and encoding of digital video signals, such as MPEG-2 and MPEG-4, have been promulgated. These standards specify with particularity the form of encoded digital video signals and how such signals are to be decoded for presentation to a viewer.
Video preprocessing techniques may be applied to incoming digital video signals so that the signals may be more efficiently compressed by subsequent video compression circuitry. For example, a preprocessor may detect noise in a frame and reduce or remove the noise in the frame before transmitting the frame to the video compression circuitry. Removing noise from digital video signals is not only important for improving the visual quality of the signal, but also for increasing the efficiency of the MPEG video encoders.
Various noise artifacts associated with digital video signals are known in the art. Impulsive noise, also known as salt-and-pepper noise, is defined as individual pixels whose intensity values are much larger or smaller than that of its surrounding neighbors. Often, these impulsive pixels are the result of some type of error or noise and require correction and/or concealment. In some instances, even if the pixel of interest correctly represents the true intensity of a given location at a particular point of time, it is still desirable to treat the impulsive pixel as noise. An example of this is in digital images and video where high frequency content, which includes impulsive pixels, is not only very distracting to a viewer but also very difficult for compression algorithms to effectively compress. The use of bits to compress these impulses takes away bandwidth that could be used more effectively on other parts of the picture. For this reason, a variety of algorithms have been developed in the prior art to reduce and/or remove impulsive noise.
A popular approach to impulsive noise removal is disclosed in "Digital Image Processing" by R. C. Gonzalez and R. E. Woods, Addison_Wesley Publishing Company, 1992, pp. 191-195. Gonzalez and Woods describe a median filter where the median of a set of local neighborhood values is calculated and may be used (adaptively or nonadaptively) to replace the pixel of interest. The median is a value that is both (a) less than half the values in the set and (b) greater than half the values in the set. Referring now to FIG. 5, there is shown an example of neighborhood data where the pixel with intensity value of 99 is the pixel of interest. As an example of median filtering, the 3×5 pixel neighborhood data shown in FIG. 5 contains the values:                (10, 15, 10, 12, 20, 15, 10, 99, 18, 10, 12, 15, 10, 20, 18).
Sorting these values results in:                (10, 10, 10, 10, 10, 12, 12, 15, 15, 15, 18, 18, 20, 20, 99).
Therefore, a median filter would use the value of 15 to replace the impulsive value of 99 at the pixel of interest in the center.
One disadvantage of median filtering for both hardware and software implementations is that the calculation of the median requires the neighborhood values to first be sorted. Sorting algorithms not only require computational resources (approximately N*log2 N operations to sort N elements) but may also require additional resources such as memory and code space. Therefore, it is desirable to have a system and method for impulsive noise removal that reduces the necessary computations, thereby resulting in a faster and more efficient method for impulsive removal.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.

Impulsive noise removal using maximum and minimum neighborhood values


A method is provided for electrically connecting a first electronic component which is not resistant to a reflowing temperature and a second electronic component which is resistant to the reflowing temperature to a substrate. The method includes the steps of applying cream solder to a first predetermined portion of the substrate so that the first electronic component is connected therewith and to a second predetermined portion of the substrate so that the second electronic component is connected therewith, mounting the second electronic component on the substrate, heating the second electronic component mounted on the substrate by reflowing so as to solder the second electronic component onto the substrate, forming a pre-soldered portion made of cream solder on the first predetermined portion of the substrate, applying flux to one of the first electronic component and the pre-soldered portion, mounting the first electronic component on the first predetermined portion of the substrate, melting the cream solder of the pre-soldered portion by heating the substrate locally, and soldering the first electronic component onto the substrate. Another method for electrically connecting an unwashable electronic component and a washable electronic component to a substrate includes similar steps to those of the method above.

The present invention relates to a method for soldering a composite module component having an electronic component (low-heat-resistant electronic component) which cannot be soldered onto a substrate simultaneously with an electronic component (heat-resistant electronic component) by reflowing, or an unwashable electronic component such as a high frequency electronic component containing a crystal oscillator which cannot be soldered onto the substrate simultaneously with a washable electronic component by reflowing.
When in the composite module component, low-heat-resistant electronic components are soldered onto the substrate simultaneously with heat-resistant electronic components by reflowing at a high temperature, solder which has connected the low-heat-resistant electronic components of the composite module component to the substrate is melted. As a result, the electrical characteristic of the composite module component is destroyed. Therefore, the heat-resistant electronic components cannot be soldered onto the substrate simultaneously with the low-heat-resistant electronic components. In electrically connecting the heat-resistant electronic component and the low-heat-resistant electronic component with the substrate, first, the heat-resistant electronic components are soldered all together onto the substrate according to a procedure as shown in FIG. 23. Then, the low-heat-resistant electronic components are manually soldered onto the substrate. According to another method, the heat-resistant electronic components are soldered all together onto the substrate by reflowing and then low temperature solder is applied to the substrate so as to solder the low-heat-resistant electronic components onto the substrate by reflowing at a low temperature as shown in FIG. 24.
In connecting to a substrate washable electronic components and unwashable electronic components having a crystal oscillator which may be destroyed when it is subjected to ultrasonic waves, the washable electronic components are soldered simultaneously onto the substrate by reflowing and washed. Then, the unwashable electronic components are manually soldered onto the substrate as shown in FIG. 25.
The above-described manual soldering of the low-heat-resistant electronic components and the unwashable electronic components are performed to decrease the action of flux and relieve the heat shock of a printed circuit board. That is, as shown in FIG. 26, electrodes 100a and 100b of a substrate 34, a heat-resistant composite module component 99, and an electronic unwashable component 103 having a crystal oscillator 101 are preheated. Then, solder 97 is supplied and melted by a soldering iron 98. Then, the solder 97 is cause to flow onto connecting portions. Thereafter, the heat-resistant electronic component 99 and the unwashable electronic component 103 are supplied to a substrate 34 and the solder 97 is then melted by the soldering iron 98. Thus, the electrodes of the electronic component 99 are soldered onto the electrodes 100a and 100b of the substrate 34.
However, it depends on an operator's workmanship as to whether or not electronic components are soldered favorably onto the substrate. Thus, the conventional soldering method is not suitable for mass production.
When the electronic components are electrically connected with the substrate in manual operation, fine solder balls scatter in melting the solder 97. When the solder balls 102 stay on an electronic circuit, the function thereof is damaged. In the case of the washable electronic components, the solder balls can be removed from the substrate by washing the substrate and the electronic components simultaneously after they have been soldered onto the substrate, but in the case of the unwashable electronic components having the crystal oscillator, the solder balls cannot be removed from the substrate because the components are unwashable.
In connecting the low-heat-resistant electronic component with the substrate by reflowing at a low temperature, the melting point of the low-temperature solder is approximately 150.degree. C. while the melting point of eutectic solder is 183.degree. C. Therefore, it is difficult to maintain the same temperature and, as such, soldering cannot be accomplished with the same quality.

Method for connecting electronic component with substrate

Matsushita Electric Industrial Co., Ltd.


A text modification mechanism is provided for formatting data such that the information can be reasonably deciphered by a human, but cannot be easily recognized by computer recognition techniques. The text modification mechanism alters printed text so that computer recognition of characters becomes difficult. Modification of the text may be accomplished with manipulation of the fonts or the background. The mechanism may also modify the text based on user preferences.

1. Technical Field
The present invention relates to data processing and, in particular, to printing documents. Still more particularly, the present invention provides a method, apparatus, and program to prevent computer recognition of data in printed documents.
2. Description of Related Art
A company may invest time and effort into producing a document that holds a value. For example, the document may include information that may be sold or the document may include secret information. However, once the document is printed, the information may be easily stolen and distributed by transforming the document into an electronic format. This may be done by scanning the document into a computer. Once the document is scanned into an image format, the computer may perform optical character recognition (OCR) on the scanned image.
OCR uses known fonts to identify characters in an image. OCR software has internal representations of the images, such as bitmaps, of each character in known fonts and compares them against the scanned document. The OCR software may then produce a text representation, such as American Standard Code for Information Interchange (ASCII).
The prior art has focused on techniques for preventing reproduction of documents using copy machines and facsimile machines. However, OCR remains as a possible method for unauthorized reproduction of a printed document. Therefore, it would be advantageous to provide a method, apparatus, and program to prevent computer recognition of data in printed documents.

Method, apparatus, and program to prevent computer recognition of data

International Business Machines Corporation


A clothes washing machine includes a water tub, a spin basket, and a clothes agitator. A vertical dehydrating shaft is fixed to the spin basket, and a laundering shaft extends coaxially within the dehydrating shaft. Upper and lower ends of the laundering shaft are connected to the agitator and a motor respectively, whereby rotation of the motor is always transmitted to the agitator. In order to selectively connect the dehydrating shaft to the laundering shaft (e.g., during a spin-drying operation), a connecting gear is mounted on the dehydrating shaft for rotation therewith and for vertical movement relative thereto. A power-driven actuator is provided for selectively moving the connecting gear up or down. When the connecting gear moves down, lower teeth thereon become operably connected to the motor so that the dehydrating shaft and laundering shaft rotate together. During a washing or rinsing operation, the connecting gear is moved up, whereby upper teeth thereon become connected to a fixed element, whereby the dehydrating shaft is fixed against rotation.

1. Field of the Invention
The present invention relates to a power system of a clothes washing machine.
2. Description of the Related Art
Generally, a washing machine includes a main body defining an outer configuration thereof, a water tub installed within the body, and a rotating drum (spin basket) and blade mounted within the water tub. A power system for driving the rotating drum and blade is mounted under the water tub.
The power system conventionally comprises a motor, a power transmission system, and a belt for connecting the motor to the power transmission system. This will be described hereinbelow with reference to FIG. 5.
As shown in the drawing, a conventional power transmission system 10 has a hollow dehydrating or spin drying shaft 11 and a laundering shaft 12 inserted into the hollow portion of the hollow dehydrating shaft 11. The laundering shaft 12 is divided into upper and lower portions, with a planetary gear unit 13 being disposed therebetween. The planetary gear unit 13 changes a rotating speed of the power transmission system 10. A brake band 14 and a brake lever 15 are disposed beside the dehydrating shaft 11 to brake the rotation of the dehydrating shaft 11. A one-way bearing 16 cooperates with the brake band 14 for suppressing rotation of a rotating drum 20 and permitting the dehydrating shaft 11 to rotate in only one direction. The bearing is mounted on an outer circumference of the dehydrating shaft 11. In addition, a clutch spring 17 and a clutch lever 18 for transmitting/interrupting power from the motor to both the dehydrating shaft 11 and the laundering shaft 12 are mounted under the one-way bearing 16. A pulley 19 on which a belt (not shown) is engaged is mounted on a lower end of the laundering shaft 12.
In this conventional power transmission system 10, torque of the motor is selectively transmitted to a rotating agitator blade 21 or both the blade and the rotating drum 20 through the clutch spring 17, thereby performing the washing and dehydrating operations. To achieve this, it is necessary that the clutch spring 17 has a high degree of tensile strength to enable the transmission or interruption of torque from the motor to the dehydrating shaft 11 and the laundering shaft 12, both of which are rotated at a high speed. However, the manufacturing process for such a spring having high tensile strength is complicated, and, as a result, manufacturing costs are increased.
In addition, the brake band 14 for preventing the rotating drum 20 from idling during the washing operation is, when it brakes the rotating drum 20 in one direction, subjected to a relatively high force generated when the rotating drum 20 is being urged to rotate by water currents being generated. As a result, the above described one-way bearing 16 must be used, making the structure complicated and increasing manufacturing costs.
Finally, an unpleasant noise is generated during the braking operation of the brake band.
As described above, the conventional power system of a washing machine is complicated with regard to the arrangement of parts for performing the washing, dehydrating and braking operations, making it difficult to manufacture the same and increasing manufacturing costs. In addition, because of the large number of parts needed for this complicated arrangement, much space is required which, in turn, acts to increase the overall size of the washer.


Embodiments of the present invention provide a comprehensive system that integrates automatically gauging and correcting stations operating in a machine environment with a universal machine monitoring for detecting defective articles, quarantining the defective articles, ensuring the defective articles are safely quarantined, analyzing the machine and article related data for providing contextual information for the defective articles produced, predicting one or more necessary actions to be taken for minimizing defects in future and achieving near zero defect quality in machine production. The comprehensive system provides such contextual information about the defects/faults in the article or the machine operations in real time and locally and remotely to any human resource.

For improvements in performances of machines and minimizing defects in the articles produced by a machine, methods and systems have been developed to monitor functioning of the machine and collect statistics/data related thereto. Technologies have been provided for automatically collecting data related to the machines, which are later presented to the human operators, shop floor engineers and remote managers for them to analyze the data manually. Depending on the analysis of the operators/Engineers/Managers, the machines are regularly checked for any faults, alterations which can be made in the functions for improving quality of the end products, implementing steps or actions to minimize defects in quality of machine production, or any necessary action or preventive measures can be calculated manually by the operator and the like. "Machine production" refers to articles/parts produced by a machine, in the foregoing description.
Machine monitoring systems have been developed to monitor the working of machines in minute detail and record the working cycles and also the stoppage intervals between them. Periods in which machine is stopped for reasons like tool change, job changeover or breaks (lunch, tea, toilet, etc.) or any other reason (Power shutdown, raw material not available) are monitored and recorded by such systems.
Therefore, present technologies have provided methods for extracting data automatically and for analysis of the data with applications on computers or Cloud and to suggest corrective measures to be adopted for the machines to work smoothly and to minimize quality defects in machine production.
However, the present technologies do not provide a comprehensive solution to achieve zero defect quality in the machine production. Such as, the present technologies fail to provide adequate solutions to automatically remove the defective articles when they are detected, while also ensuring that that the defective article is safely removed from the production cycle. Further, the present technologies also do not provide appropriate solutions to provide insights for defects occurring in machine production, and also fail to provide solutions which explain the reasons for faulty productions.
Additionally, the present technologies fail to provide a system which may automatically anticipate any corrective measures to be taken for minimizing defects in quality of articles produced. It may be a case too, that the present technologies do not provide an effective timeline of implementing a corrective measure for improving the quality or minimizing the defects in the production. Hence, even after determining a preventive measure, an operator may delay in implementing that measure since he/she may be unaware of the time based urgency for taking that preventive measure.
Furthermore, in present machine production environment, customers expect near zero quality (e.g. few per million), but the 'skills' (Measurement skill, Analytical skill and Correction input skill) of skilled operators are declining. This is a very worrisome situation for manufacturers of machined articles (such as in automotive, aerospace, defense, railways, infrastructure, etc.). Also, auto-gauging stations are being used but are generally of elementary type without sophisticated algorithms. More importantly, their effectiveness cannot be monitored in real time.
There is also no method of linking events related to machine operation or machine behavior (for example tool changed, re-started after lunch, etc.) with production of defective articles and determining reasons for the article being defective (such as due to Bore or diameter etc.). Also, there is no method of monitoring in real time, the quarantining of defective articles produced.
Therefore, there is a need of a smart and comprehensive system and method that provides for minimizing defects in the machine production or even to achieve zero defect quality in the machine production, while also providing real time contextual information about the defects occurring in the machine production.

System and a method to enable zero defect production


The present invention relates to a flat display screen anode of the type including at least two sets of alternate parallel bands of anode conductors coated with phosphor elements to be excited by primary electrons, these bands being separated from one another by insulating bands including, at least at the surface, a material with a secondary emission coefficient which is lower than or equal to unity, at least in the energy range of the primary electrons.

1. Field of the Invention
The present invention relates to flat display screens, and more particularly to so-called cathodoluminescence screens, the anode of which carries luminescent elements, separated from one another by insulating areas, and likely to be excited by electron bombarding. This electron bombarding requires the biasing of the luminescent elements and can come from microtips, from layers with a low extraction potential or from a thermo-ionic source.
2. Discussion of the Related Art
To simplify the present description, only color microtip screens will be considered hereafter, but it should be noted that the present invention generally relates to the various above-mentioned types of screens and the like.
FIG. 1 shows the structure of a flat color microtip display screen.
Such a microtip screen is essentially comprised of a cathode 1 having microtips 2 and of a grid 3 provided with holes 4 corresponding to the locations of microtips 2. Cathode 1 is placed facing a cathodoluminescent anode 5, a glass substrate 6 of which constitutes the screen surface.
The operating principle and a specific embodiment of a microtip screen are described, in particular, in U.S. Pat. No. 4,940,916 of the Commissariat a l'Energie Atomique.
Cathode 1 is organized in columns and is comprised, on a glass substrate 10, of cathode conductors organized in meshes from a conductive layer. The microtips 2 are implemented on a resistive layer 11 deposited on the cathode conductors and are arranged within the meshes defined by the cathode conductors. FIG. 1 partially shows the inside of a mesh and the cathode conductors do not appear on the drawing. Cathode 1 is associated with grid 3 organized in lines. The intersection of a line of grid 3 and of a column of cathode 1 defines a pixel.
This device uses the electric field which is created between cathode 1 and grid 3 to extract electrons from microtips 2. These electrons are then attracted by phosphor elements 7 of anode 5 if the latter are adequately biased. In the case of a color screen, anode 5 is provided with alternate bands of phosphor elements 7r, 7g, 7b, each corresponding to a color (Red, Green, Blue). The bands are parallel to the cathode columns and are separated from one another by an insulator 8, generally silicon oxide (SiO.sub.2). The phosphor elements 7 are deposited on electrodes 9, comprised of corresponding bands of a transparent conductive layer such as indium and tin oxide (ITO). The sets of red, green, blue, bands are alternately biased with respect to cathode 1, so that electrons extracted from the microtips 2 of a pixel of the cathode/grid are alternately directed towards the phosphor elements 7 facing each of the colors.
The control for selecting the phosphor 7 (phosphor 7g in FIG. 1) which is to be bombarded by the electrons from the microtips of cathode 1 imposes to control, selectively, the biasing of phosphor elements 7 of anode 5, color per color.
Generally, the rows of grid 3 are sequentially biased at a potential of about 80 volts, while the bands of phosphor elements (for example 7g in FIG. 1) to be excited are biased under a voltage of about 400 volts via the ITO band on which the phosphor elements are deposited. The ITO bands, carrying the other bands of phosphor elements (for example, 7r and 7b in FIG. 1), are at a low or zero potential. The columns of cathode 1 are carried to respective potentials between a maximum emission potential and a no emission potential (for example, respectively 0 and 30 volts). The brightness of a color component of each of the pixels in a line is thus determined.
The choice of the values of the biasing potentials is linked with the features of phosphor elements 7 and of microtips 2. Conventionally, below a potential difference of 50 volts between the cathode and the grid, there is no electronic emission, and the maximum emission used corresponds to a potential difference of 80 volts.
A disadvantage of conventional screens is that they have a low lifetime, that is, after a relatively short operating time (of about one hundred hours), the brightness of the screen decreases significantly and destructive phenomena due to the forming of sparks between the screen cathode and anode may even sometimes be observed.
Further, after a certain operating time, the color appears to vary and no longer corresponds to the screen control settings. This phenomenon will be called herein "color shift". In practice, this means that at least one of the bands of phosphor material adjacent to the biased bands starts exhibiting a luminescence.
The origin of this phenomenon was not well understood up to now. It was thought to be due to the fact that electrons accumulate on the insulating areas 8 between the bands of phosphor material and ensure a conduction to neighboring bands. To avoid this phenomenon, several prior art techniques have been provided for, one of which consists in separating by short time intervals the biasings of the anode bands between two successive sub-color frames, and applying a negative voltage pulse on the band just biased, before positively biasing the next anode band to be excited.
However, this method has the disadvantage of being relatively complex to implement since it complicates the delivery of the anode supply voltages, which are voltages with high values (a few hundred volts) and it is prejudicial to the brightness of the screen.

Implementation of a flat display screen anode


A glove-doll entertainment system is presented. The glove-doll system allows for playing with the doll separate from the glove, playing with the doll attached to the glove, or using the glove as a hand covering without the doll. The appendages of the doll directly and removeably attach to exterior surfaces of the glove's finger receiving cavities. Each of the attached appendages can be separately articulated by finger movement. The doll is three dimensional and is physically distinct from the glove. Contemplated dolls can include an electronic circuit that generates a sound when an appendage is moved. A sequence of sounds can be generated by movement of a plurality of appendages to generate a song or a story. Contemplated gloves are sufficiently thick and waterproof to replace a regular pair of winter gloves.

When children go outside in cold weather, they typically wear gloves to keep their hands warm or dry. While wearing gloves, it is difficult to carry dolls or other toys, and sometimes toys are dropped, damaged, or even lost. As any parent knows when a child loses a favorite toy, the child become inconsolable. Having a doll or other type of toy configured to removeably and directly attach to an exterior surface of a glove can advantageously allow a child to play with the doll while also retaining full utility of the glove as a hand protecting device.
Some dolls include a hand-receiving cavity such that the toy can be used as a hand puppet. Others have developed various forms of hand-puppets combined with gloves. For example, U.S. Pat. No. 4,304,065 to Baiera describes a hand puppet associated with an in operative glove component. However, in Baiera the hand goes inside the body of the puppet, and all finger receiving cavities are disposed inside an appendage of the puppet while the glove is present to create an illusion of a glove. Thus, the glove lacks utility separate from the puppet. Another Example includes U.S. Pat. No. 4,610,640 to Amici, which describes puppet in combination with a glove. In Amici, the glove represents an integral part of the puppet where the fingers of the glove operate as appendages of the puppet. Again, the glove lacks utility as a separate hand protecting device because the glove is permanently affixed to the puppet.
Yet others have coupled toys with a glove while keeping the toy and glove distinct from each other. Great Britain patent 1,428,859 to Stubbmann describes a marionette coupled with a glove component where movement of the glove translates into movements of the marionette. In Stubbmann the toy couples with a glove by strings and also requires a stand for additional support. In this case the toy is configured to be at a distance from the glove to increase the illusion that marionette is autonomously controlled. Another example where a toy is distinct from a glove includes U.S. Pat. No. 7,003,810 to Goldkind, which describes a finger puppet in combination with a partial glove concealed in the knee pockets of a pair of jeans. In this case the partial glove lacks utility as a separate device and the small finger puppets can not be removed. In other references, as in the Educational Insights (See FIG. 1; see also URL www.educationalinsights.com/product/teachers/category/imaginative+-+role+play/puppets/storytelling+glove.do) and in U.S. patent application publication 2009/0193562 to Magglo, the disclosed systems require multiple distinct puppets or body parts where the puppets and body parts attach to a glove. In these cases, appendages of the puppets lack the ability to move independently from each other or the puppets are too small could be lost.
Independent movement of a doll's appendages would be desirable in a glove-doll combination. For example, U.S. Pat. No. 4,992,070 to Mullen describes an articulated toy figure having rings attached to certain movable limbs where the rings are intended to clamp onto a user's fingers. Finger movement then translates to movement of the toy's limb movement. Interestingly, in Mullen, the articulated toy is not attached to a glove component, but directly attaches to a finger.
A puppet capable of making sounds in response to user finger movement would also be desirable for increased play value. U.S. patent application publication 2004/0121702 to Siebert describes a finger toy that can generate a sound when tapped against a hard object. Ideally, a puppet would generate sounds in response to appendage movement, possibly generating a story.
A more ideal glove-doll combination would include a glove that can also be leveraged simply as a glove and include a physically distinct doll capable of removeably attaching to the glove via its appendages. In such a configuration, the glove retains its full utility as a glove and the doll can be played with separately without the glove. Furthermore, the doll can be attached to the glove for combined play as a puppet. A sufficiently large doll decreases the risk of loss. Even in view of the previous efforts directed toward combining dolls with gloves, no known effort has been focused on providing a doll having at least some of the appendages configured to removeably and directly attach to an exterior surface of the glove where movement of a finger within a finger receiving cavity of the glove causes independent and separate movement of the doll appendages.
Thus, there is still a need for a glove-doll combination that allows for play with the doll separate from the glove, play with the doll when attached to the glove, and use of the glove without the doll.


There is provided a speaker unit comprising: an elliptical vibrating diaphragm; a cylindrical voice coil secured at one end thereof on the center of the elliptical vibrating diaphragm; a frame structure for movably supporting the vibrating diaphragm, said frame structure being formed into a rectangular or elliptical shape and having a through hole in the center thereof; a magnetic circuit formed by (1) a top plate having a rectangular shape and having a through hole in the center thereof, (2) a plate-shaped magnet having a rectangular shape and having a through hole in the center thereof, (3) a back plate having a rectangular shape and having an upright pole on the center thereof. In this speaker unit, the top plate, the plate-shaped magnet and the back plate each has a width which is narrower than that of the frame structure in its shorter axis.

The present invention relates to a speaker unit, in particular to a speaker unit which is thin in thickness and has an elliptical shape.
There has been known a thin type speaker unit which is for use in a television set and whose vibrating diaphragm is usually formed into an elliptical shape. On the other hand, it is usually required that a magnetic circuit of a speaker unit be formed in a manner such that it can provide a uniform magnetic flux to the surface of a cylindrical voice coil. Accordingly, it is often required that a top plate and a permanent magnet each having a circular doughnut shape be used so that the whole magnetic circuit has a cylindrical shape.
In fact, a thin type speaker unit usually has a magnetic circuit whose outer diameter is equal to or smaller than a width in a short axis direction of a frame structure which supports a vibrating diaphragm. In this way, a speaker unit as a whole may be made smaller, thus meeting with a requirement of making a compact speaker unit.
However, in a thin type speaker unit as above related, since a magnetic circuit has to be made small in size due to a restriction caused by a width in the short axis direction of a vibrating diaphragm, the magnetic flux to be applied to the surface of a voice coil will have a low density, resulting in a problem that the speaker unit has only a low sensitivity.


A reproducing apparatus for a disc in which data recorded on an optical disc are read out by an optical pickup and reproduced, is disclosed. Before start of reproduction, it is determined if the disc loaded into the apparatus is a data disc on which information data such as letter or character data or picture data are recorded, or an audio disc on which audio signals are recorded, and the playback mode is automatically selected as a function of the type of the optical disc loaded into the apparatus. At the start time of the reproducing operation from the disc, the type discriminating data recorded on the disc are read out and, as a function of the contents of the type discriminating data, switching is made automatically between the data reproducing operation and the audio signal reproducing operation, while the type of the optical disc is displayed on the display section on the basis of the type discriminating data.

1. Field of the Invention
This invention relates to a reproducing apparatus for a disc in which optical discs having different information data recorded thereon, such as a data disc on which letter or character data or picture data, such as Japanese dictionary data, English-Japanese dictionary data or encyclopedia data, are recorded, or an audio disc on which audio signals are recorded may be reproduced selectively. More particularly, it relates to a reproducing apparatus for a disc in which it is determined if the optical disc loaded in the reproducing apparatus is a data disc or an audio disc and in which the reproducing operation may be switched automatically between the data disc reproducing operation and the audio disc reproducing operation depending on the type of the loaded optical disc.
2. Description of the Prior Art
Among the discs on which information data are pre-recorded, there are a data disc on which letter or character data or picture data, such as Japanese dictionary data, English-Japanese dictionary data or encyclopedia data are recorded, and an audio disc, on which audio signals are recorded.
There is proposed a reproducing apparatus for a disc which enables reproduction of an optical disc which may be a data disc or an audio disc. For reproducing a data disc by such a disc reproducing system, the letter or character data or the picture data recorded on the data disc are read out by an optical pickup and the read-out data are displayed as visual data on the display by way of performing a data reproducing operation. For reproducing an audio disc on which audio signals are recorded, the audio signals recorded on the audio disc are read out by an optical pickup and the read-out signal data are outputted as audio signals for driving a speaker by means of an audio processing circuit by way of performing an audio signal reproducing operation.
In this manner, the reproducing operation for information signals recorded on the optical disc differs as a function of whether the disc is a data disc or an audio disc.
Therefore, when reproducing the optical disc with the use of the above mentioned reproducing apparatus for a disc, it is grasped in advance whether the optical disc loaded in the system is the data disc or the audio disc and the operating mode is set as a function of the disc type before proceeding to reproduction.
With such reproducing system for a disc, since the reproducing mode is selected as a function of the optical disc to be loaded, that is, as a function of whether the disc is the data disc or the audio disc, should a mistake be made in the selection of the reproducing mode, it becomes impossible to reproduce data from the disc loaded in the system.
For example, when the operating mode is set to the audio disc reproducing operation, and the data disc is loaded by mistake, the data signals read from the optical disc are reproduced as though they were musical sound signals, so that, in a majority of cases, only the voice as the noise is reproduced. As a matter of course, the letter or character data recorded on the data disc cannot be displayed as visible data.
Conversely, when the operating mode is set to the data disc reproducing operation, and the audio disc is loaded by mistake, the information data such as letter or character data or picture data to be recorded on the data disc or the processing data for these information data cannot be read, so that the operation of reproducing the data read out by the optical pickup cannot be performed. For example, the operation of reproducing the data read out from the optical disc cannot be performed in succession to the data read-out operation. Should the user become aware of the error in loading the disc or in the setting of the operating mode and exchange the disc or the mode setting, it becomes possible to reproduce the desired optical disc. However, should the user not become aware of the error in loading the disc or in the setting of the operating mode, it may occur that the error be mistaken for a trouble in the disc reproducing system. There is also an inconvenience in that a laborsome operation is necessitated for exchanging the disc or re-setting the operating mode.

Optical disk reproducing apparatus which automatically determines the format type of the optical disk


This invention relates to an improvement in coatings particularly suited for the preparation of paper products having an ink jet coating applied thereto and to the resulting paper products. The improvement in ink jet coatings resides in the incorporation of a primary amine functional polyvinyl alcohol (PVOH/PVNH2) as a polymeric binder. One form of an amine functional polyvinyl alcohol is produced by the hydrolysis of a copolymer of vinyl acetate and N-vinylformamide or vinyl acetate and allyl amine. Another is the polyvinyl butyral derivative of polyvinyl alcohol which typically is formed by the reaction of a 4-amino alkyl aldehyde dialkyl acetal, such as 4-aminobutyraldehyde dimethyl acetal with polyvinyl alcohol.

This invention relates to paper products having a unique coating thereon rendering them well suited for use with ink jet printers.
Advances in ink jet printing technology have placed new demands on the printed paper and paper coatings. To function properly the printed substrate must quickly absorb the ink and ink vehicles directly after printing, maximize the ink optical density, minimize ink bleed and wicking, and provide a means of making the inks waterfast.
Ink jet coatings generally comprise silica pigment having a high absorption capability and a polymeric binder such as a poly(vinyl alcohol) binder having a high binding strength. A variety of additives have been utilized to improve coating properties. Cationic additives, for example, have been added to help with ink waterfastness and lightfastness. Other variations in the ink jet coating formulations include the use of non silica pigments such as clays, aluminum hydrate, calcium carbonate, titanium dioxide, magnesium carbonate and the use of binders such as styrene-butadiene, poly(vinyl pyrrolidone), polyvinyl acetate, acrylic binders, and starch.
The following patents and articles are representative of various resins and ink jet paper coatings.
U.S. Pat. No. 4,818,341 discloses the addition of a cationic polymer e.g. hydrolyzed vinyl acetate or vinyl propionate/N-vinyl formamide copolymers to paper stock to enhance the dry-strength in all types of paper and paper board, e.g., writing paper and packaging papers. The polymers are added in an amount of from 35-150 grams per square meter for paper and up to 600 grams per square meter for paper board.
U.S. Pat. No. 4,880,497 discloses the addition of water-soluble copolymers containing polymerized vinyl amine units, e.g., a hydrolyzed vinyl acetate/N-vinyl formamide copolymer to paper stock prior to sheet formation in an amount of from 0.1-5% based on dry fiber.
Japanese-laid open Kokai application 5-278323 discloses a recording sheet having good ink absorptivity, image quality and excellent water resistance which comprises a dye fixing layer and ink adsorption layer laminated thereon. One of the principal components of the dye fixing layer applied to the recording sheet is a cation modified polyvinyl alcohol. Cation modified polyvinyl alcohols are characterized as hydrolyzed copolymers of vinyl acetate and ethylenically unsaturated monomers having quaternary ammonium salt groups. The content of the cationic group is from 0.1-10 mole percent.
An abstract, of Japanese 63162276A2 discloses an image acceptor for ink jet recordings. The image acceptor includes silica pretreated with water soluble resins either on the recording surface or within the acceptor. A solution of sodium silicate and sulfuric acid is mixed with 5% of a cation modified polyvinyl alcohol and applied to a paper sheet and then an ink applied thereto.
Japanese Patent 05139023 discloses an aqueous based ink jet coating comprising silica pigment and a fully hydrolyzed, medium molecular weight poly(vinyl alcohol) coating. This coating is applied to a paper support at coat weights of 0.7 to 0.8 g/cm2 to provide high color quality images with good dot shape.
German patent 514633 A1 921125 describes an ink jet coating which contains 50% silica pigment, 40% poly(vinyl alcohol) having a hydrolysis value of 92.5%, and 10% of a cationic polyacrylamide. When applied to a paper substrate at a coating weight of 10 grams/m2, this coating provides excellent color density and small dot diameters yielding excellent print fidelity.
Japanese patent 01186372 A2 890725 describes the addition of polyacrylamide to an ink jet coating comprising silica pigment and fully hydrolyzed low molecular weight poly(vinyl alcohol). This coating yield good smudge resistance and lightfastness.
Japanese patent 06247036 A2 940906 discloses the use of a cationic polyethyleneimine quaternary ammonium salt in combination with silica pigment and fully hydrolyzed low molecular weight poly(vinyl alcohol) as an ink jet receiving layer.
Japanese patent 61134291 A2 860621 discloses a cationic PVOH binder for use in an ink jet coating; the binder used is a saponified trimethyl-3-(1-acrylamidopropyl)ammonium chloride-vinyl acetate copolymer with a percent hydrolysis of 98.5 and a cationic content of 3 mole % and a degree of polymerization of 1750. Coatings using this binder with silica pigment provide excellent print fidelity and good water resistance to paper.
U.S. Pat. No. 5,405,678 discloses an ink jet paper having a substrate coated with a non coalesced latex film comprised of a hydrophobic polymer, e.g., ethylene-vinyl chloride copolymers, acrylic latexes, silica, and dispersants.
U.S. Pat. No. 5,270, 103 discloses receiver sheets suited for printing with aqueous based inks, such as those used in ink jet printing systems. The coating formulation is comprised of a pigment and a binder consisting of polyvinyl alcohol and another polymer, e.g., cationic polyvinyl alcohol and poly(vinyl pyrrolidone).
U.S. Pat. No. 6,096,826 discloses the synthesis of a amine functional polyvinyl alcohol via the reaction piperidone with poly(vinyl alcohol) particles. The end product was found to be useful as a mordant/binder for ink jet coated papers.
U.S. Pat. No. 6,096,440 discloses the use of an ink jet recording medium having an ink receiving layer composed of hydrophilic resin, a block copolymer of polyvinyl alcohol and a hydrophobic polymer. US ""440 further discusses the use of a cationic-modified poly(vinyl alcohol), Kurray CM-318, produced by Kuraray Co. Ltd. as a binder for the ink jet receiving layer.
This invention relates to an improvement in paper products having an aqueous based ink jet coating applied to its surface. The improvement generally resides in the incorporation of an a primary amine functional polyvinyl alcohol (PVOH/NH2) as a polymeric binder in the ink jet coating. One form of an amine functional polyvinyl alcohol is produced by the hydrolysis of a copolymer of vinyl acetate and N-vinylformamide (PVOH/PVNH2), another formed by the polymerization of vinyl acetate and allyl amine, and another is the 4-aminobutyral derivative of polyvinyl alcohol.
Several advantages are associated with the paper products incorporating the improved ink jet coating. These advantages include:
the incorporation of a primary amine functional polyvinyl alcohol as a polymer binder in the ink jet coating eases the makedown procedure of the coating formulation by eliminating the need to add cationic materials;
the addition of a primary amine functional polyvinyl alcohol provides excellent binding strength with the silica pigments used in ink jet coatings;
the addition of a primary amine functional polyvinyl alcohol provides excellent ink optical density with regard to monochrome black, composite black, and primary colors;
the addition of a primary amine functional polyvinyl alcohol provides excellent waterfastness to the printed inks;
the addition of a primary amine functional polyvinyl alcohol provides for excellent lightfastness of the inks;
the addition of a primary amine functional polyvinyl alcohol provides for excellent rheological response in terms of shear thickening response when used in conjunction with silica pigment thereby helping the paper coater achieve a greater coating solids level which can allow for higher coat weights and increased production speeds; and
the addition of a primary amine functional polyvinyl alcohol provides excellent ink dry time after printing onto the coated ink jet paper.
Typically, a primary amine functional polyvinyl alcohol is selected from the group consisting of: hydrolyzed copolymers of vinyl acetate and N-vinylamide, a hydrolyzed copolymer of vinyl acetate and allylamine, and primary aminoalkylal derivatives of polyvinyl alcohol.

Ink jet printing paper incorporating amine functional poly(vinyl alcohol)


Disclosed are a circuit and a method for an analog-to-digital conversion with programmable resolution. The circuit includes a resistor ladder comprising a plurality of resistors coupled to a plurality of comparators; wherein the resistor ladder is further coupled to a switch logic circuit and a plurality of current sources; and wherein the switch logic circuit is configured to control an operation of a plurality of switches to alter conversion resolution of the ADC, and an error correction circuit coupled to the outputs of the plurality of comparators, wherein the ADC is configured to perform a first conversion step and a second conversion step, and wherein the ADC is configured to perform only the first conversion step when programmed for lower conversion accuracy and higher conversion speed.

1. Field of the Invention
The present invention relates to electronic analog-to-digital converter circuits. More particularly, the present invention relates to an analog-to-digital converter circuit and method having a programmable resolution.
2. Background Information
A conventional Flash analog-to-digital converter (ADC) is a circuit which converts an analog input signal to a digital output signal at high speed. Flash ADCs are well suited to applications requiring large bandwidth. The number of bits at the output of these circuits varies, with those circuits having the greater number of output bits having the greater resolution and a greater potential accuracy. A disadvantage of flash ADCs is that the circuitry for high resolution output flash converters grows exponentially as the number of bits of resolution increases. A further disadvantage of flash ADCs is that they consume large amounts of power and area, and, thus, can be quite expensive. Hence, flash ADCs are generally reserved for high frequency applications that cannot be addressed using other slower ADCs. Flash ADC applications include, for example, satellite communication, radar processing, sampling oscilloscopes, high-density disk drives, and the like.
A conventional flash ADC circuit 100 is illustrated in FIG. 1. The ADC circuit 100 achieves an n-bit conversion by using a resistor network of 2n resistors and 2n comparators. The conventional flash ADC circuit 100 comprises a resistive network of 2n resistors including a first resistor 112, a second resistor 114, and up to a 2nth resistor 116. The voltage node between each resistor in the resistive network provides a reference voltage up to the topmost node (Vref) 101. An input signal (Vin) 103 is provided to a comparator network of 2n comparators including a first comparator 122, a second comparator 124, and up to a 2nth comparator 126. The comparators compare a given voltage from the resistive network to the input signal (Vin) 103. The output of the comparators is provided to a logic circuit 132, where the output is decoded to the appropriate digital output signal (adcout) 105.
Another conventional flash ADC, also called as a two-step flash ADC, is illustrated in FIG. 2. The two-step conventional flash ADC 200 achieves an n-bit conversion by employing a resistor network of 2n resistors and a comparator network of 2n-2 comparators. The two-step conventional flash ADC 200 comprises a resistive network of 2n resistors including a first resistor 212, a second resistor 214, and up to a 2nth resistor 216. Similar to the conventional flash ADC 100, the resistor network in the two-step flash ADC 200 provides several reference voltages up to the topmost resistor node voltage (Vref) 201. An input signal (Vin) 203 is provided to a comparator network of 2n-2 comparators including a first comparator 222, a second comparator 224, and up to a 2n-2th comparator 226. The output of the resistor network is provided to a switching network 210. The conventional two-step Flash ADC 200 performs two conversions, a coarse conversion and a fine-tuned conversion, of the input signal 203. The switching network 210 is reconfigured by the output of the coarse conversion. The circuitry for the switching network 210 varies by implementation choice. For example, such circuitry can comprise a Digital-to-Analog converter (DAC), a subtraction circuit, another lesser-resolution Flash ADC, or the like. The circuitry in the switching network 210 is generally set on clock phases to determine whether a coarse or fine conversion is being performed. The output of the switching network 210 is further provided to the comparators. The output of the comparators is provided to a logic circuit 220, where the output is decoded to generate an appropriate digital output signal (adcout) 205.
A disadvantage of the conventional flash ADC 100 is that as the conversion resolution increases, there is an exponential growth of the die area and an increase in die cost as the number of bits of resolution 'n' increases, due to the array of 2n resistors and 2n comparators required.
A disadvantage of the conventional flash ADC 200 is that although the numbers of comparators has been reduced, a complicated switching network and additional circuitry are still required, which consumes area and power.
A disadvantage of conventional two step ADCs is that they are not programmable to only use the coarse step when less accuracy and higher conversion speed are required. Conventional two-step analog to digital conversion methods require a resistor element of very high accuracy, which increases the design complexity of the Analog to Digital converter.
It would be desirable to provide an improved ADC having a higher resolution, programmability, and a faster conversion speed with a minimal increase in die area and power consumption.

Analog-to-digital converter circuit and method with programmable resolution


A read/verify circuit for multilevel memory cells includes: a read terminal selectively connectable to a plurality of array cells, having respective array threshold voltages; a plurality of reference cells, having respective reference threshold voltages; and a plurality of threshold-detection circuits, for detecting the array thresholds and the reference thresholds. In particular, the read terminal and the reference cells are each connected to a respective threshold-detection circuit. Each threshold-detection circuit is provided with a respective detector element of a resistive type, set so as to be traversed by a current response to turning-on of the respective array cell or reference cell associated thereto.

1. Field of the Invention
The present invention relates to a read/verify circuit for multilevel memory cells with ramp read voltage and to a read/verify method thereof.
2. Discussion of the Related Art
As is known, the need to increase the capacity of non-volatile memories has led to the fabrication of multilevel memories, in which each cell is able to store more than one bit. The information, stored as an amount of charge in a floating-gate region, is encoded by fractioning the entrapped charge and, consequently, the threshold voltage. In this way, the characteristic of a multilevel cell is described by a number of curves representing the drain current as a function of the gate voltage and associated each to a different logic value. The result obtainable in terms of storage density is obviously better, the higher the number of levels of each cell.
At the same time, the development of techniques of fabrication of semiconductors, in particular the increase in lithographic precision, has enabled a considerable reduction in the dimensions of the individual cells and has made it possible for increasingly compact devices to be obtained.
The further increase in the storage density in non-volatile memories meets, however, with a limit in the precision required in particular for the read/verify circuits, which are traditionally based upon current comparison. In fact, the increase in the number of levels and the decrease in the gain of the cells caused by the reduction of the dimensions require discriminating currents that are increasingly closer to one another.
Recently, read/verify circuits with ramp read voltage have been proposed. In practice, the same ramp read voltage is supplied simultaneously to the gate terminals of a cell selected in a memory array and of a plurality of reference cells. The reference cells have been previously programmed so as to have intermediate threshold voltages between the possible threshold voltages envisaged for the array cells. As the read voltage increases, the reference cells are turned on in sequence; also the selected array cell is activated, but its turning-on is staggered with respect to the reference cells. In subsequent turning-on instants, then, the reference cells and the array cell start conducting the same reference current, which is injected through a plurality of respective current-mirror circuits. The passage of the current through each cell, whether an array cell or a reference cell, is detected by a respective operational amplifier, which compares the voltage on the drain terminal of the cell itself with a reference voltage. As the read voltage increases, the operational amplifiers associated to the reference cells switch in sequence, and the switching is stored in an appropriate register, which is incremented. When, instead, the operational amplifier associated with the memory cell switches, the register is "frozen" and is no longer modified until there is a reset command for a new read/verify cycle. In practice, the final configuration of the register indicates the relative position of the voltage threshold of the array cell with respect to the threshold voltages of the reference cells and consequently corresponds to the data stored.
The read/verify circuits with ramp read voltage, albeit presenting advantages as compared to the current comparison circuits, suffer from some limitations, due principally to the presence of operational amplifiers and of current-mirror circuits. Operational amplifiers, in fact, are complex and cumbersome, have high power consumption and, moreover, tend to introduce offsets that limit the maximum obtainable precision. Consequently, also the number of levels that can be discriminated is not optimal. Current mirrors, instead, are sensitive to the fluctuations of the supply voltage and can thus easily introduce read errors when the levels of the threshold voltage are close to one another.

Read/verify circuit for multilevel memory cells with ramp read voltage, and read/verify method thereof


A procedure and installation of the same for the control of image processing devices using only the data required; thus, avoiding saturation of the memories of the components involved and/or the communications bandwidth. The procedure and installation are simple and reliable such as not to require the involvement of an expert user or a service staff member. The procedure includes the standardization of the data identifiers for each image processing device via the identification of the identifier containing a value for each data point and checking that the scale of each data point is equivalent to a predetermined scale. The installation includes a standardization system for such purpose.

An image processing device can be a printer, a copier, a fax machine, a wide or narrow format plotter, a multifunctional printing device combining two or more of the previous devices or a 3D printer.
Currently there are controls, both procedures and installations, that cover all or most of the data available on image processing devices, which in most cases exceeds a total of 1000 data fields, which usually saturates the memories of the elements involved as well as the communications bandwidth, with most of this data being unnecessary.
Said controls usually have a control device and an intermediary between them and the image processing devices, a data collection device. This data collection device usually stores a complete list with all of the data on data collection devices, which requires it to have a relatively large memory.
On the other hand, the image processing devices require a diversity of supplies of many different types. The control and prediction of the requirements for providing said supplies is currently performed by a person, which requires a service staff member to decide, based on their experience, when to replace the supplies, as well as carrying out the replacement itself.
Some known controls help the service staff member to determine the correct moment for replacing the supplies. Said controls focus on balancing the cost of unavailability of the device and the cost of the service, including staff expenses, materials and transport costs. Despite this, these controls still require the intervention of a service staff member.
The current reality of the technology of most, if not all image processing devices, is that they have been designed to remain operational without the need for a service staff member, but only through simple physical tasks that are mostly performed by the user. Any user may by a supply, such as a cartridge, without ever talking to a sales person or expert or service person, using an online shop, for example, and can install the supply following the instructions included with the supply. The consequence of not using a service staff member and with current controls is largely affecting existing image processing devices, such as printers, which try to reduce the risk of failure from a lack of supplies and also to minimize the cost of such a service, without achieving this. The user either stores too many supplies and installs them without taking into account the maximum use thereof (i.e., they may install a cartridge before the previous one runs out) or carelessly forgets to buy the supply, and when the current one runs out the device stops working with the resulting cost to the company's production chain. The situation becomes even more complex due to the fact that in a single base of image processing devices there are usually devices of many different models and manufacturers, which means that each one uses different supplies and the devices use them and generate information about them in different ways. In a practical sense, the service staff member should store as many different supply references as there are different models of devices in the company, with the resulting high cost of purchasing them and of managing the complexity of the facilities.
All the above processes use data on the image processing devices. Each data point has an identifier, a label, that allows the control or user to know amongst all the data which is the one that is of interest to them. However, given the large amount of manufacturers and models there is a lot of data and there are even more identifiers, which causes the aforementioned problem. It becomes necessary, as stated in the invention described herein, to homogenize or standardize the data for better management, such as explained below.

Method for controlling image-processing devices and facility for carrying out such method


Systems, methods, apparatus and software can configure, support, and make use of a coordinator virtual device to determine which node or nodes of a cluster should be ejected from the cluster as a result of a cluster partition or other error event. Fencing software operating on the cluster nodes monitors the cluster for a cluster partition (split-brain) event, and when such an event occurs, software on the nodes attempts to gain control of the coordinator virtual device. A node that succeeds in gaining control of the coordinator virtual device survives. Nodes failing to gain control of the coordinator virtual device remove themselves or are removed from the cluster. The coordinator virtual device can be established by a virtual device configuration server which provides coordinator virtual device access to cluster nodes acting as virtual device configuration clients.

Distributed computing systems are an increasingly important part of research, governmental, and enterprise computing systems. Among the advantages of such computing systems are their ability to handle a variety of different computing scenarios including large computational problems, high volume data processing situations, and high availability situations. For applications that require the computer system to be highly available, e.g., the ability to maintain the system while still providing services to system users, a cluster of computer systems is a useful implementation of the distributed computing model. In the most general sense, a cluster is a distributed computer system that works together as a single entity to cooperatively provide processing power and mass storage resources. With a cluster, the processing load of the computer system is typically spread over more than one computer, thereby eliminating single points of failure. Consequently, programs executing on the cluster can continue to function despite a problem with one computer in the cluster. In another example, one or more computers of the cluster can be ready for use in the event that another computer in the cluster fails. While each computer in a cluster typically executes an independent instance of an operating system, additional clustering software is executed on each computer in the cluster to facilitate communication and desired cluster behavior.
FIG. 1 illustrates a simplified example of a cluster 100. The members of the cluster include Server A 110 and Server B 120. As members of cluster 100, servers 110 and 120 are often referred to as "hosts" or "nodes." Thus, a node in a computer cluster is typically an individual computer system having some or all of the common as is well known in the art. FIG. 11 (described later in this application) illustrates some of the features common to cluster nodes. Another common feature of a cluster is the ability of the nodes to exchange data. In the example of FIG. 1, servers 110 and 120 can exchange data over network 150, typically a local area network (LAN), e.g., an enterprise-wide intranet, or a wide area network (WAN) such as the Internet. Additionally, network 150 provides a communication path for various client computer systems 140 to communicate with servers 110 and 120. In addition to network 150, servers 110 and 120 can communicate with each other over private network 130. As shown, private network 130 is only accessible by cluster nodes, i.e., Server A 110 and Server B 120. To support the high availability of cluster 100, private network 130 typically includes redundancy such as two network paths instead of one. Private network 130 is used by the nodes for cluster service message passing including, for example, the exchange of so-called "heart-beat" signals indicating that each node is currently available to the cluster and functioning properly.
Other elements of cluster 100 include storage area network (SAN) 160, SAN switch 165, and storage devices such as tape library 170 (typically including one or more tape drives), a group of disk drives 180 (i.e., "just a bunch of disks" or "JBOD"), and intelligent storage array 190. These devices are examples of the type of storage used in cluster 100. Other storage schemes include the use of shared direct-attached storage (DAS) over shared SCSI buses. SAN 160 can be implemented using a variety of different technologies including fibre channel arbitrated loop (FCAL), fibre channel switched fabric, IP networks (e.g., iSCSI), Infiniband, etc.
SAN switch 165 and storage devices 170, 180, and 190 are examples of shared resources. The most common shared resource in a cluster is some form of shared data resource, such as one or more disk drives. Using a shared data resource gives different nodes in the cluster access to the same data, a feature that is critical for most cluster applications. Although a disk device is perhaps the most common example of both a shared resource and a shared data resource, a variety of other types of devices will be well known to those having ordinary skill in the art. Moreover, although servers 110 and 120 are shown connected to storage array storage devices through SAN switch 165 and SAN 160, this need not be the case. Shared resources can be directly connected to some or all of the nodes in a cluster, and a cluster need not include a SAN. Alternatively, servers 110 and 120 can be connected to multiple SANs. Additionally, SAN switch 165 can be replaced with a SAN router or a SAN hub.
One known problem among computer system clusters occurs when one or more of the nodes of the cluster erroneously believes that other node(s) are either not functioning properly or have left the cluster. This "split-brain" condition results in the effective partitioning of the cluster into two or more subclusters. Causes of the split-brain condition include failure of the communication channels between nodes, e.g., failure of private network 130, and the processing load on one node causing an excessive delay in the normal sequence of communication among nodes, e.g., one node fails to transmit its heartbeat signal for an excessive period of time. For example, if cluster 100 is configured for failover operation with an application program operating on server A 110 and server B 120 existing in the cluster to takeover for server A should it fail, then complete failure of private network 130 would lead server B to conclude that server A has failed. Server B then begins operation even though server A has not in fact failed. Thus, the potential exists that the two servers might attempt to write data to the same portion of one of the storage devices thereby causing data corruption. The solution is to ensure that one of the nodes cannot access the shared resource, i.e., to "fence off" the node from the resource.
Cluster partitioning can take a variety of other forms and have a variety of detrimental effects. For example, a node might attempt to reenter a cluster after the node has already been successfully excluded from the cluster. Thus, the reentering node might encounter a cluster environment setup to exclude the node and interpret that instead as a partition event. Additionally, cluster partitioning can be problematic even though there is no shared resource among the cluster nodes. For example, if one node of a cluster is supposed to be the node interacting with a client device and another node detects a cluster partition, the client device could ultimately communicate with the wrong node thereby leading to some manner of error.
Many prior art fencing mechanisms and cluster partition recovery schemes rely on cluster nodes and the cluster software operating on those nodes to have direct access to and/or control of certain shared resources. For example, such mechanisms or schemes might utilize specific coordinator or quorum disk drives, control of which is used to determine which node or nodes survive a cluster partition event and which should be fenced off. These schemes present a number of disadvantages when certain storage virtualization techniques, e.g., out-of-band virtualization techniques are employed.
For example, in-band and out-of-band storage virtualization, as opposed to host-based storage virtualization or storage-based virtualization, provides users with virtualization between the hosts and the storage. Using a storage appliance such as a specialized switch, router, server, or other storage device, in-band and out-of-band storage virtualization allows for the same level of control and centralization across the storage architecture. An in-band virtualization appliance is physically located between the host and the storage. The appliance takes the disk requests from the host and fulfills the host's request from the storage attached to the other side of the appliance. This functionality is essentially transparent to the host because the appliance presents itself as disk. Out-of-band appliances logically present themselves as if they are located in the data path between the host and storage, but they actually reside outside of the data path. Thus, in an out-of-band implementation the data flow is separated from the control flow. This is accomplished, for example, with the installation of a "thin" virtualization driver on the host in the I/O data path. The out-of-band appliance provides the virtualization driver with the storage mappings. The virtualization driver presents virtual storage devices to the applications and file systems on the host and sends the blocks of data directly to correct destinations on disks. In contrast, the in-band appliance requires no host-side changes. It acts as a surrogate for a virtual storage device and performs mapping and I/O direction in a device or computer system located outside of the host.
Accordingly, it is desirable to have scalable, flexible, and robust I/O fencing schemes for handling cluster partition conditions in certain storage virtualization environments to prevent data corruption on a shared data resource used by the cluster.

System and method for resolving cluster partitions in out-of-band storage virtualization environments


A heterojunction bipolar transistor having base, emitter and undoped amorphous silicon collector regions formed on a crystalline silicon substrate. A p-n junction is formed in the substrate, beneath the collector region. A single such transistor may be configured as a static memory device which may be reversibly switched between stable first and second states by applying a voltage of about 8 to 10 volts to the collector and by selectively applying positive or negative pulses of about .+-.0.75 volts to the base.

Heterojunction devices are formed by combining two different semiconductor materials such as crystalline silicon and amorphous silicon. Amorphous silicon is a desirable material to employ because it can be biased to exhibit two distinct states which differ by several orders of magnitude; namely, an "off" state characterized by very low electrical current conductivity, and an "on" state characterized by comparatively high electrical current conductivity. By appropriately controlling the biasing of such material, in the pulsed regime, one may selectively switch the material back and forth between the two states. Controllable, reversible switching between distinct, stable states is a basic requirement of memory cells of the type used in computer memory applications.
The prior art reveals the use of doped amorphous silicon in heterojunction devices such as bipolar transistors which exhibit high current gain: Symons, et al, "Silicon Heterojunction Bipolar Transistors With Amorphous and Microcrystalline Emitters", Solid-State Electronics 30, p. 1143 (1987); and, in solar cells: Carlson, "Amorphous Solar Cells", IEEE Transactions on Electron Devices ED-24,p. 449 (1977). Amorphous silicon heterojunction devices such as electrically programmable read only memories ("EPROM"s) which exhibit irreversible switching behaviour are known: Shacham-Diamond, et al "The Electrical Properties of Ion-Implanted Amorphous Silicon Programmable Element in the Unprogrammed State", IEEE Transactions on Electron Devices ED-37, p. 159 (1990). Two-terminal doped amorphous silicon heterojunction devices capable of exhibiting dynamic, reversible switching behaviour are also known: Chen, et al, "Electrical and Optical Characteristics of an a--Si:H/c--Si Heterojunction Switch", Japanese Journal of Applied Physics 29, p. 1415 (1990). Chen et al have also reported three-terminal devices incorporating amorphous silicon, but have reported investigation of switching behaviour only in respect of two-terminal devices.
The present invention facilitates the fabrication of three-terminal heterojunction bipolar structures utilizing undoped amorphous silicon. A single structure of this type has been found to exhibit static switching behaviour. That is, the structure can be controllably switched between the two conductivity states aforesaid; and, when controllably switched to a particular state, remains in that state until controllably switched to the other state. Conventional static memory devices comprise several inter-coupled transistor structures. The invention accordingly facilitates simplified construction of static memory devices which are less complex than prior art static memory devices.

Inverted heterojunction bipolar device having undoped amorphous silicon layer


A computer-implemented method includes accessing a set of multicomponent marine noise data exhibiting a plurality of polarization vectors at each of a plurality of co-located pressure and particle motion data points on a marine seismic survey apparatus; and determining a set of perturbation noise data for the marine seismic survey apparatus from the polarization vectors. Computer readable program storage media are encoded with instructions that, when executed by a processor, perform the computer-implemented method. A computing apparatus is programmed to perform the computer-implemented method.

1. Field of the Invention
This invention disclosure relates to marine seismic surveying, and, in particular, to estimation and correction of perturbations on seismic particle motion sensors in such a survey.
2. Discussion of Related Art
This section of this document is intended to introduce various aspects of the art that may be related to various aspects of the present invention described and/or claimed below. This section provides background information to facilitate a better understanding of the various aspects of the present invention. As the section's title implies, this is a discussion of related art. That such art is related in no way implies that it is also prior art. The related art may or may not be prior art. It should therefore be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.
Seismic exploration involves surveying subterranean geological formations for hydrocarbon deposits. A survey typically involves deploying seismic source(s) and seismic sensors at predetermined locations. The sources impart acoustic waves into the geological formations. Features of the geological formation reflect the pressure waves to the sensors. The sensors receive the reflected waves, which are detected, conditioned, and processed to generate seismic data. Analysis of the seismic data can then indicate the presence or absence of probable locations of hydrocarbon deposits.
Some surveys are known as "marine" surveys because they are conducted in marine environments. Note that marine surveys may be conducted not only in saltwater environments, but also in fresh and brackish waters. Marine surveys come in at least two types. In a first type, an array of seismic cables (known as "streamers") and seismic sources is towed behind a survey vessel. In a second type, an array of seismic cables (known as "ocean bottom cables"), each of which includes multiple sensors, is laid on the ocean floor, or seabed, and a seismic source is towed from a survey vessel.
Historically, towed array, marine seismic surveys only employed pressure waves and the receivers detected any passing wavefront. This includes two types of wavefronts. The first are those reflected upward to the receivers from the geological formation. The second are those that are reflected downward from the surface of the water. The upward reflections are desirable because they generally contain information about the geological formation under survey. The downward reflections are undesirable because they interfere with the upward reflections and reduce the bandwidth of the seismic signal.
The art has therefore recently begun moving to "multicomponent" surveys in which, for example, not only is the passing of a wavefront detected, but also the direction in which it is propagating. Knowledge of the direction of travel permits determination, for instance, of which wavefronts are traveling upward and which are traveling downwards. Multicomponent towed-array surveys include a plurality of receivers that detect not only the pressure wave, but also the velocity, or time derivatives (e.g., acceleration) thereof, of the passing wavefront. These receivers will hereafter be referred to as "particle motion sensors" because they measure the velocity or acceleration of displaced particles. The pressure sensor is typically a hydrophone, and the particle motion sensors are typically geophones or accelerometers.
However, multicomponent surveys are more sensitive to what may be called "perturbations". One kind of perturbation, for example, is what is known as an "alignment perturbation". Sensors in a streamer that form a part of a towed array are frequently oriented in an orthogonal x-y-z coordinate system in which the x-y-z axes are defined as in-line with the streamer, cross-line to the streamer, and in depth. In an alignment perturbation, the sensor is misaligned relative to the streamer such that one or more of its x-y-z axes is out of alignment with the corresponding in-line, cross-line, and depth axes of the streamer. This is but one example of a perturbation, and there are others. Another kind, for example, pertains to amplitude sensitivities.
Perturbations are undesirable because they also lead to errors in the seismic data that is acquired in the survey. Errors in the data, in turn, can lead to errors in the analysis for the location of the hydrocarbon deposits. Those in the art have therefore begun to develop techniques by which this error can be eliminated, or at least mitigated.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.

Estimating and correcting perturbations on seismic particle motion sensors employing seismic source signals


A test circuit to test rise delay/fall delay performance on a semiconductor device may comprise a latch to latch data at its input responsive to a clock signal. The latch may source an output signal related to the data latched. A buffer chain may be configured to serially propagate the signal sourced by the latch from the latch output back to the clock input, as the clock signal. A reset/set input of the latch may be configured to receive a reset/set signal from an intermediate node of the buffer chain.

When producing or grading performance of a semiconductor product, test circuits may assist characterization of the product or identification of process variations that may be associated with the semiconductor fabrication. One parameter that may characterize semiconductor products or indicate a variation in process may include the speed of performance.
Test circuits onboard a semiconductor product may be used to characterize certain parameters of semiconductor product. Oscillators may produce a frequency and provide information about the operating speed of a device. But, in order to obtain more precise information about individual elements of the device or the processes of its fabrication to enable isolation of process variations and effects, information regarding the separate rise and fall delay characteristics of the oscillating signal may be needed. As used herein, a rise delay generally refers to the propagation delay through an element or block when receiving a rising edge (low to high transition) at an input. Similarly, a fall delay generally refers to the propagation delay when receiving a falling edge (high to low transition).
The duty cycle of the signal resulting from the oscillator may provide one avenue for such information. However, measurement of the precise duty cycle may be difficult for a variety of reasons. For example, it may be difficult to make a path from the ring oscillator output to the tester input equal for both rising and falling edges across all process variations. Secondly, testers may not have the capabilities for measuring an accurate duty cycle of a clock. Additionally, the output clock from an oscillator might need to be divided in order to make it slow enough for its frequency to be measured by customary testers. Further, such frequency division circuits could be complicated and cumbersome to implement, especially when trying to maintain certain aspects of the original signal.

Method of measuring performance of a semiconductor device and circuit for the same


The invention concerns a method of wet chemical etching of a wafer comprising at least one surface layer of silicon-germanium (SiGe) for etching by dispensing an etching solution deposited on a rotating wafer, the method being characterized in that it comprises a first etching step in which said etching solution is dispensed from a fixed position located at a predetermined distance from the center of the wafer, and a second etching step in which the etching solution is dispensed radially from the center of the wafer and over a maximum distance which is less than the radius of said wafer.

A number of techniques exist for preparing such wafers. One example of one of the most effective current techniques for fabricating sSOI or SGOI type wafers is the production of an active layer of strained silicon (sSi) or relaxed SiGe by transfer thereof to an insulating support (for example a layer of SiO2 on a silicon substrate) using the Smart Cut® technique, to produce the desired heterostructure. Particular examples of implementations of such fabrication techniques are described in United States patent application US 2004/053477 and International patent application WO 2004/006311.
The finishing step of said wafers involves a selective etching and optional chemical-mechanical polishing procedure to eliminate the layer or layers subsisting above the silicon layer after transfer thereof to the "receiver" substrate and detachment from the "donor" substrate.
The term "selective etching" as used here means a chemical attack method which can selectively eliminate the upper layer of a given material (a layer of SiGe, for example) without attacking the next layer (strained silicon, for example), consequently termed a stop layer, by adjusting the composition of the chemical solution.
Because of the thinness of the active strained silicon layer (of the order of 200 angstroms (Å)), it is important to be able to control with great accuracy the thickness of said layer and the final surface quality. Such a requirement in the present case necessitates optimizing the selective etching procedure which is normally used.
For the usual method termed the "single wafer" method (since it processes wafers individually rather than collectively), selective etching is carried out by dispensing a chemical solution (CH3COOH/H2O2/HF mixture) directly over the surface of the wafer via a dispensing nozzle which is displaced from the center of the wafer over a radius of ±40% of the total radius while the wafer rotates, which causes non-uniform etching: the central portion of the wafer is more deeply etched than the edge (a phenomenon which is characterized by the term "edge-slow" for that type of etching).
In the same manner, polishing carried out prior to selective etching, for example by chemical-mechanical polishing (CMP) tends to etch the center more than the edges of the-wafers, as shown in FIGS. 1 and 2 which show the surface quality of an SiGe wafer after polishing and selective etching. In FIG. 1, the layer of SiGe 1 already has a "dish" shaped surface (SAP) after polishing alone, which is accentuated following selective etching (SAG). FIG. 2 shows the over etching which results at the center of the SiGe layer compared with the edges thereof.
When the wafer comprises a layer of strained silicon sSi beneath the superficial SiGe layer, the lack of etching uniformity (carried out directly or after polishing) causes over etching of the sSi layer located beneath the SiGe layer at the center of the wafer while SiGe residues remain at the edge of the wafer. Thus, it will be understood that concatenations of CMP and selective etching steps or selective etching alone cannot directly result in sufficient uniformity of thickness and roughness of the denuded sSi layer. This lack of uniformity is particularly noticeable with large diameter wafers such as 300 millimeter (mm) diameter wafers, for example.

S.O.I.Tec Silicon on Insulator Technologies


A receive circuit having a sampling circuit and a threshold generating circuit. The sampling circuit generates a first sample value having either a first state or a second state according whether an incoming signal exceeds a first threshold level, the first threshold level corresponding to a first threshold value. The threshold generating circuit combines a first control value and a second control value to generate the first threshold value and provides the first threshold value to the sampling circuit.

Electrical pulses transmitted on a band-limited signaling path disperse in time as they travel from source to destination. In systems in which data is transmitted as a sequence of level-encoded electrical pulses, such time-domain dispersion results in a blending of neighboring pulses; an effect known as dispersion-type inter-symbol interference (ISI). Dispersion-type ISI becomes more pronounced at faster signaling rates, ultimately degrading the signal quality to the point at which distinctions between originally transmitted signal levels may be lost.
FIG. 1 illustrates a prior-art signaling system having a transmitter 101, signal path 102 and receiver 103. The transmitter includes post- and pre-tap output drivers 109 that mitigate dispersion-type ISI by generating dispersion-countering, pre-emphasis signals based on previously transmitted values (post-tap data) and the next-to-be-transmitted data value (pre-tap data), stored in shift register elements 107 and 104, respectively. The pre-emphasis signals are wire-summed with a primary output signal, generated by primary output driver 105, that corresponds to the data value being transmitted.
In a low-noise system, the drive strengths of the post- and pre-tap output drivers would theoretically be adjusted based on errors between receiver-sampled signal levels and expected signal levels (e.g., as shown by error indication, "e" at 112) until the pre-emphasis signals generated by the transmitter effect a transfer function (W) that is an exact inverse of the transfer function (P) of the signal path 102, thereby yielding a waveform at the input of receiver 103 that is identical to the primary output signal (i.e., W*P=1). This effect is illustrated in the waveforms of FIG. 2, which illustrates received signal levels with and without pre-emphasis at 116 and 114, respectively. In practical high-speed signaling systems, however, the transmitter is usually peak power constrained and therefore unable to provide the level of pre-emphasis needed to restore received signals to originally transmitted levels, illustrated as normalized +/−1 signal levels in FIG. 2. Also, as shown at 118, in a level-encoded signaling protocol (e.g., pulse amplitude modulation (PAM)), the overall attenuation of the received signal is a function of the transmitted data pattern itself, with low frequency components (e.g., sequences of same-level transmissions) having a higher amplitude, approaching the +/−1 levels, than high frequency components (e.g., alternating sequences of different-level transmissions) which are attenuated to +/−a levels.
Together, the transmitter power constraint and the data-dependent attenuation present a number of challenges in the prior-art signaling system 100. A fundamental problem is how to generate the error signal used to adjust the drive strengths of the transmitter output drivers considering that no known data level can be reached for all data patterns. That is, if the known reference levels +/−1 cannot be reached in high-frequency data patterns, attempting to converge to such levels tends to produce non-optimal drive-strength settings from the standpoint of link performance.
One prior-art solution for generating error signals that may be used to update the drive strengths of the transmitter output drivers is to provide a variable gain element, G (shown in dashed outline in FIG. 1), at the receive-side of the signaling path 102. In theory, the gain element may be used to restore the incoming signal to the desired signaling level. While some improvement may be realized by such an approach, as signaling rates progress deeper into the gigahertz range, signals are often attenuated 10 to 20 db and more. Consequently, the gain-bandwidth product required to restore such high data rate signals to originally transmitted levels is beyond the capability of most practical amplifiers.
In view of the challenges involved in dynamically updating drive strengths of transmit-side output drivers, many system designers opt for a simpler approach, setting the drive strengths based on empirical results obtained in particular system configurations. While such static drive strength settings work well in many systems, non-optimal settings often result in systems which are subject to post-production configuration changes (e.g., adding modules, circuit boards or other components that affect signaling system characteristics), and systems that are sensitive to process variations and to changes in environmental factors such as voltage and temperature.

Offset cancellation in a multi-level signaling system