A time-interleaved analog-to-digital converter stores in a correction information memory, correction information required to correct an error between signals output by a plurality of N analog-to-digital converters in advance. At this time, in order to enable acquisition of data required for a correction processing within a short period of time, a signal generator causes the plurality of N analog-to-digital converter to input a calibration signal including a plurality of signal components, each of which is positioned at a desired frequency in a bandwidth in which N/2 times of a sampling frequency Fs is defined as an upper limit, the signal components appearing in a bandwidth in which half times of the sampling clock frequency Fs is defined as an upper limit by sampling the analog-to-digital converters. A correction information calculating unit carries out a spectrum analysis relevant to analog-to-digital converted signals output by the plurality of N analog-to-digital converters in response to the calibration signal, thereby obtaining an amplitude and a phase of a plurality of signal components, newly obtaining the correction information, based on the amplitude and phase, and updating contents of the correction information memory in accordance with newly obtained correction information.

Recently, as one of the high speed signal processing systems, there has been discussed the achievement of a spectrum analyzer or the like capable of sampling a broadband analog signal to convert the sampled signal into a digital signal sequence, and carrying out a variety of signal processings such as spectrum analyzing at a high speed.
In such a high speed signal processing system, the mere use of an exiting analog-to-digital converter limits high speed processing responsiveness.
Therefore, it is thought to employ a time-interleaved analog-to-digital converter enabling high speed processing equivalently by carrying out analog-to-digital conversion in accordance with a time interleave scheme using a plurality of the existing analog-to-digital converter.
FIG. 23 is a block diagram depicting a basic configuration of a time-interleaved analog-to-digital converter 10 which has been conventionally known.
FIG. 24 is a timing chart showing an operation of the time-interleaved analog-to-digital converter 10 shown in FIG. 23 for the purpose of explanation.
That is, in this conventional time-interleaved analog-to-digital converter 10, an analog input signal x(t) as shown in FIG. 24 (a) is input to an input terminal 10a.
This analog input signal x(t) is branched to a plurality of N signal paths by a signal divider 11, and then, the respective branched signals are input correspondingly to N analog-to-digital converters 120 to 12N−1 controlled by a sampling control unit 13 described later, whereby the input signals are converted into a plurality of digital signal sequences X0 to XN−1.
The plurality of digital signal sequences X0 to XN−1 each are input to a signal switching device 14 controlled by the sampling control unit 13 described later.
Here, each sampling control unit 13 has N clocks C0 to CN−1 as shown in (b1) to (bN) shown in FIG. 24, the clocks being internally generated, i.e., N sampling clocks C0 to CN−1 which have a cycle Ts and whose phase has been shifted by Ts/N are supplied to N analog-to-digital converters 120 to 12N−1, respectively correspondingly.
In addition, the sampling control unit 13 assigns to the signal switching device 14 a specifying signal ADNUM (0 to N−1) for specifying the analog-to-digital converter that carries out sampling from among the analog-to-digital converters 120 to 12N−1, as shown in FIG. 24(d), the converters being internally generated.
This specifying signal ADNUM (0 to N−1) is provided as a switching signal for sequentially selectively switching a plurality of digital signal sequences X0 to XN−1 in the signal switching device 14, and outputting the switched signal trains to an output terminal 10b.
Then, analog-to-digital converters 120 to 12N−1 sample input values x(P), x(P+1), x(P+2), . . . of an analog input signal x(t) at a timing at which each of clocks C0 to CN−1 has been received from the sampling control unit 13, and converts the sampled data to digital data X0, P, X1, P+1, X2, P+2, . . . as shown in (c1) to (cN) of FIG. 24.
Each of these sampled data X0, P, X1, P+1, X2, P+2, . . . are output to the signal switching device 14.
The signal switching device 14 sequentially selects the sampled data X0, P, X1, P+1, X2, P+2, . . . output from the analog-to-digital converter 120 to 12N−1 specified by the specifying signal ADNUM from the sampling control unit 13 from among the analog-to-digital converters 120 to 12N−1, and outputs to an output terminal 10b a digital signal sequence Y(n) in which the sampled data are arranged sequentially in order of sampling as shown in FIG. 24(e).
The thus obtained digital signal sequence Y(n) becomes equivalent to that obtained by sampling an input signal x(t) in a cycle Ts′ that is 1/N of a clock cycle Ts.
Therefore, this time-interleaved analog-to-digital converter 10 can carry out high speed sampling while using low speed analog-to-digital converters 120 to 12N−1.
However, in the above-described conventional time-interleaved analog-to-digital converter 10, there is a problem that an error occurs with a result of signal processing of the obtained sample values by a signal processing system.
This problem is caused by the fact that an error occurs with outputs of the analog-to-digital converters 120 to 12N−1 as a result of a difference in distribution characteristics of the signal divider 12 itself or frequency characteristics of a distribution path and a difference in frequency characteristics of the analog-to-digital converters 120 to 12N−1 when the input signal x(t) is input to be divided to the plurality of analog-to-digital converters 120 to 12N−1.
Therefore, in the case where the signal processing system requires high analog-to-digital conversion precision, there is a need for correcting each of the above-described errors in the above-described conventional time-interleaved analog-to-digital converter 10.
For this calibration, a correction processing may be made by obtaining correction information while a calibration signal is input to the above-described time-interleaved analog-to-digital converter 10.
Specifically, in a state in which the calibration signal has been input, the output data is obtained from each analog-to-digital converter, and the obtained data or a processing result relevant to the data is compared, thereby obtaining correction information required to equalize conversion characteristics of each analog-to-digital converter including an input path in advance.
Then, in a state in which a signal targeted for analog-to-digital conversion has been input to the above-described conventional time-interleaved analog-to-digital converter 10, a correction processing is made based on the correction information with respect to an output of each analog-to-digital converter.
In order to carry out such a correction processing, for example, a technique of obtaining information required for calibration is disclosed in patent document 1.
That is, this technique is configured to select by a switch either of a sine wave signal output from a signal generator incorporated in the above-described conventional time-interleaved analog-to-digital converter or an analog signal input from an input terminal and targeted for conversion, so as to enable input to a plurality of analog-to-digital converters.
In addition, in this technique, at the time of calibration, an output signal of a signal generator is input to a plurality of analog-to-digital converters, and information required for calibration is obtained from its output data.
Patent document 1: Jpn. Pat. Appln. KOKAI Publication No. 6-152410

Time-interleaved analog-to-digital converter and high speed signal processing system using the same


A method, system, and computer-readable storage medium are disclosed for generating a triangulation of a path comprising one or more path segments. In one embodiment, one or more interior triangles in the triangulation may be automatically generated. Each interior triangle may comprise a line segment between a starting point and an ending point of a path segment, leaving a remainder of a first plurality of exterior regions of the path. A first set of one or more exterior triangles in the triangulation may be automatically generated by inscribing a triangle in each exterior regions of the path whose corresponding portion of the one or more path segments does not meet a flatness threshold. Successive sets of exterior triangles may be generated within remaining exterior regions while the flatness threshold is unmet.

1. Field of the Invention
The present invention is directed to computer systems; and more particularly, it is directed to tessellation of geometric objects using computer systems.
2. Description of the Related Art
As the power and complexity of personal computer systems increase, graphics operations are increasingly being performed using dedicated graphics rendering devices referred to as graphics processing units (GPUs). As used herein, the terms "graphics processing unit" and "graphics processor" are used interchangeably. GPUs are often used in removable graphics cards that are coupled to a motherboard via a standardized bus (e.g., AGP, PCI, or PCI Express). GPUs may also be used in game consoles and in integrated graphics solutions (e.g., for use in some portable computers and lower-cost desktop computers). Although GPUs vary in their capabilities, they may typically be used to perform such tasks as rendering of two-dimensional (2D) graphical data, rendering of three-dimensional (3D) graphical data, accelerated rendering of graphical user interface (GUI) display elements, and digital video playback. A GPU may implement one or more application programmer interfaces (APIs) that permit programmers to invoke the functionality of the GPU.
To reduce demands on central processing units (CPUs) of computer systems, GPUs may be tasked with performing operations that would otherwise contribute to the CPU load. Accordingly, modern GPUs are typically implemented with specialized features for efficient performance of common graphics operations. For example, a GPU often includes a plurality of execution channels that can be used simultaneously for highly parallel processing. A GPU may include various built-in and configurable structures for rendering digital images to an imaging device.
Digital images may include raster graphics, vector graphics, or a combination thereof. Raster graphics data (also referred to herein as bitmaps) may be stored and manipulated as a grid of individual picture elements called pixels. A bitmap may be characterized by its width and height in pixels and also by the number of bits per pixel. Commonly, a color bitmap defined in the RGB (red, green blue) color space may comprise between one and eight bits per pixel for each of the red, green, and blue channels. An alpha channel may be used to store additional data such as per-pixel transparency values.
Vector graphics data may be stored and manipulated as one or more geometric objects built with geometric primitives. The geometric primitives (e.g., points, lines, polygons, Bézier curves, and text characters) may be based upon mathematical equations to represent parts of digital images. The geometric objects may typically be located in two-dimensional or three-dimensional space. Suitable image editors, such as Adobe Illustrator® (available from Adobe Systems, Inc.), may be used to perform operations on these objects. Typical operations include rotation, translation, stretching, skewing, changing depth order, and combining objects with other objects. While raster graphics may often lose apparent quality when scaled to a higher resolution, vector graphics may scale to the resolution of the device on which they are ultimately rendered.
To render vector graphics on raster-based imaging devices (e.g., most display devices and printers), the geometric objects are typically converted to raster graphics data in a process called rasterization. Prior to final rasterization, surfaces defined by the geometric objects may be covered with polygons (e.g., triangles or quadrilaterals) in a process called tessellation or triangulation. The polygons may also be referred to as tessellae, and the arrangement of polygons may be referred to as a triangulation or a mesh. Each polygon is defined by at least three vertices, and each vertex may be characterized by color and alpha values. Because tessellation of a shaded surface may produce many polygons, a surface may be rendered with fine variations in the color and alpha values.
In tessellating a two-dimensional geometric object that includes a curved path, the curve may be approximated by a series of line segments. The polygon may then be tessellated using conventional polygon triangulation techniques such as Siedel, Watson, Delaunay, etc., to produce a set of triangles. The approximation of the curve may be referred to as "flattening." The resulting polygon typically has a large number of vertices in the area approximating the curve. However, the number of line segments and the corresponding number of vertices used in approximating the curve may be dependent upon the resolution of the target output device (e.g., a display device or printer).
One prior approach to tessellation uses "cancelling triangles" to produce a multi-cover triangulation describing the interior of a two-dimensional geometric object. Using this approach, a point may be chosen (e.g., the center of the object bounds), and triangles connecting every edge to the chosen point may be produced. However, this approach may produce undesirably "spiky" triangles on polygons having a high vertex count such as polygons having segments that approximate a curve. FIG. 1A illustrates an example triangulation 50 produced using this approach.
As the resolution of the polygonal boundary increases, the triangulation may become even "spikier" using this prior approach. Furthermore, the increased "spikiness" of a triangulation may increase the number of pixels and/or tiles that include multiple triangles and are therefore painted more than once in rendering the polygon. Thus, the increased "spikiness" of a triangulation may place increased demands on the computing resources used in rendering, and performance may be degraded accordingly. For example, when a GPU is used to render the triangulated polygon, a pixel shader of the GPU may be invoked more often for areas encompassing particularly "spiky" triangles, such as the central region of the example triangulation 50.

Efficient multi-resolution curve rendering


A method for the prevention or treatment of Influenza virus infection or Adenovirus infection by administering an effective amount of a compound of Formula (I), Formula (II), or similar compound to an individual in need is provided.

Viruses can be divided into several (arbitrary) classifications based upon the type of nucleic acid that they carry and the mode of expression. Table 1 illustrates one classification scheme based upon "The International Code of Virus Classification and Nomenclature", and the classification system developed by Dr. David Baltimore (incorporated herein by reference)
TABLE 1Group NameNucleic Acid TypeOrderExamplesDNA virusesDouble strandedOrder:Ex. Enterobacteria phage T4DNA virusesCaudoviralesUnassignedEx. Family AdenoviridaevirusesEx. Family HerpesviridaeEx. Family Polymaviridae (simiam virus40)Ex. Family Poxviridae (Cowpox virus,Variola virus-smallpox)Single strandedUnassignedDNA virusesbacteriophagesUnassignedEx. Family ParvoviridaevirusesRNA virusesDouble strandedUnassignedEx. Family ReoviridaeRNA virusesviruses(+) single-strandedOrder:Ex. Family Coronaviridae (coronavirus,RNA or mRNA-likeNidoviralesSARS)virusesUnassignedEx. Family Flaviviridae (Yellow fevervirusesvirus, West Nile virus, Hepatitis C virus)Ex. Family Picornaviridae (poliovirus,rhino virus, hepatitis A virus)Ex. Togaviridae (Rubella virus)(−) single-strandedOrder:Ex. Family Paramyxoviridae (measlesRNA virusesMononegaviralesvirus, mumps virus)(non-segmentedEx. Family Rhabdoviridae (rabies virus)negative strandedviruses)SegmentedEx. Family Orthomyxoviridae (Influenzanegative strandedviruses)virusesDNA and RNASingle-strandedUnassignedEx. Family Retroviridae (Retroviruses,reverseRNA reversevirusesHIV)transcribingtranscribing virusesvirusesDouble-strandedUnassignedEx. Family Hepadnaviridae (Hepatitis BDNA reversevirusesvirus)transcribing virus
The design and discovery of new antiviral drugs can be directed against either viral or cellular targets. Drugs that inhibit viral proteins are more likely to be virus-specific and are more prone to the development of resistance. Thus, there is an urgent need for broad spectrum antiviral drugs that can be used in mono- or combined therapy to treat the numerous viral diseases caused by DNA viruses, RNA viruses and DNA and RNA reverse transcribing viruses for which limited or no therapeutic options are currently available. The demand for new effective and safe antiviral strategies has become an increasingly important problem to solve in recent years due to the rising prevalence of chronic viral infections such as HIV and hepatitis B and C, the emergence of new viruses or viral strains such as the SARS coronavirus and pathogenic Avian Influenza strains, the ever-present threat of viral pandemics from agents like virulent strains of influenza A, and the potential danger of hemorrhagic fever viruses and eradicated viruses such as variola virus being exploited as bioterrorist weapons.
A limited number of chronic viral diseases, which affect millions of people world-wide (e.g., 40 million individuals are HIV-infected), can be controlled to some degree, but no cures are currently available. As a result, infected individuals provide a reservoir for the respective virus through which naïve individuals become infected, thereby, perpetuating the problem of viral infection of significant human populations with these pathogens. Currently available antiviral drugs, such as the nucleoside reverse transcriptase inhibitors (NRTIs) used to inhibit viral replication of specific pathogenic viruses, have resulted in recognizable improvements in the ability to control infections with these pathogens and to improve the quality and length of life of infected individuals. A partial list of currently available antiviral drugs used to inhibit viral replication of specific pathogenic viruses is provided in Appendix 2 (for eg. the NRTIs). The therapies listed have resulted in recognizable improvements in the ability to control infections from these pathogens and to improve the quality and length of life of infected individuals. However, currently available classes of antiviral agents have limited utilities due to their narrow scope of activities against different viruses and/or problems with significant drug-induced toxicities. In addition, the modes of action of the NRTIs and other drugs in current clinical use predispose to the development of drug resistance through viral mutations. Finally, many currently available drugs have considerable side effects that prevent their wide spread use to achieve treatment or prevention goals.

Broad spectrum antiviral and methods of use


A method is provided for rendering a color image with a plurality of separations with a multi-level successive-filling halftoning process using a single screen for a plurality of separations. For a separation to be processed, first, from the possible multiple levels for the separation, the set of levels that would be used and the number of dots corresponding to the different levels are decided. These decisions are based on the input level for the separation and input levels for the prior process separations. The location of the dots to be printed for the different levels for the separation is then decided by using the halftone screen, while simultaneously taking into account the placement of printed dots for the prior separations. The selection is done so as to best disperse dots and minimize overlap.

In today's business and scientific world color has become essential as a component of communication. Color facilitates the sharing of knowledge and ideas. Companies involved in the development of digital color print engines are continuously looking for ways to improve the accuracy and total image quality of their products.
Color images are commonly represented as one or more separations, each separation comprising a set of color density signals for a single primary or secondary color. Color density signals are commonly represented as digital gray or contone pixels, varying in magnitude from a minimum to a maximum, with a number of gradients between corresponding to the bit density of the system. Thus, a common 8 bit system provides 256 shades of each primary color. A color can therefore be considered the combination of magnitudes of each pixel, which when viewed together, present the combination color Usually, printer signals include three subtractive primary color signals (Cyan, Magenta and Yellow) and a Black signal which together can be considered the printer colorant signals. Each color signal forms a separation and when combined together with the other separations, forms the color image.
Printers commonly provide a limited number of output possibilities, and are commonly binary, i.e., they produce either a dot (ink drop) or no dot at a given pixel location. Thus, given a color separation with 256 shades of each additive primary color, a set of binary printer signals must be produced representing the contone effect. This process is referred to as halftoning. In such arrangements, over a given area and the separation having a number of contone pixels therein, each pixel value of an array of contone pixels within the area is compared to one of a set of preselected thresholds (the thresholds may be stored as a dither matrix and the repetitive pattern generated by this matrix is considered a halftone cell) as taught for example in U.S. Pat. No. 4,149,194 to Holladay. The effect of such an arrangement is that, for an area where the image is a contone, some of the thresholds in the matrix will be exceeded, i.e., the image value at that specific location is larger than the value stored in the dither matrix for that same location, while others are not. In the binary case, the pixels or cell elements for which the thresholds are exceeded might be printed as Black or some color, while the remaining elements are allowed to remain white or uncolored, dependent on the actual physical quantity described by the data. Since the human visual system tends to average out rapidly varying spatial patterns and perceives only a spatial average of the micro-variation in spot-color produced by a printer, the halftone process described above can be used to produce a close approximation to the desired color in the contone input.
The dither matrix of threshold values is often referred to as a "screen", and the process of generating the binary image from the contone image using the screen is called "screening". Conventional digital halftones start as a number of isolated dots which grow bigger as more colorant is requested on the paper. These screens are referred to as clustered-dot screens. The fundamental rate at which the dots in a clustered dot screen are repeated is commonly referred to as the screen's spatial frequency [Note R. Ulichney, "Digital Halftoning", MIT Press, Cambridge, Mass., 1987]. The higher the screen spatial frequency, the finer and smoother appearing the image and also the greater is the capacity for the dots to represent fine detail in the image. Dithering creates problems in color document reproduction where the repeating pattern of a screen through the image, when superposed over similar repeating patterns in multiple separations, can cause moiré or other artifacts, particularly in a printing system with less than ideal registration between separations.
Stochastic, or non-periodic screening is an alternative to conventional clustered dot screens. Instead of producing dots that grow with increased colorant on paper, the stochastic screening method produces a well-dispersed pattern of isolated dots at spaced pixel locations. Thus there is no fundamental periodicity in the dots, instead the design of the screen attempts to produce patterns with pleasant noise characteristics. The pleasant noise characteristics are achieved by designing the screen so as to distribute the noise energy in the region of high spatial frequency, where the human visual system has a significantly reduced sensitivity. In this respect, U.S. Pat. No. 5,673,121 to Wang, discloses a stochastic halftone screening method for designing an idealized stochastic screen and is herein incorporated by reference as it discloses a particular stochastic screen useful in implementation of the subject invention, as will be more fully explained below. One of the advantages of stochastic, or non-periodic screening over periodic screening, is the suppression of moiré.
Color stochastic screening has typically been implemented in the prior art by using the same screen for all separations (dot-on-dot) or by using independent screens (possibly obtained by shifting/rotating/flipping a single screen). These methods do not produce halftones with maximal ink dispersion and optimized spatial frequency response because there is no control of interseparation overlaps. The less successful the screening processes, the less smooth, i.e. more grainy, the resultant image appears. It is of course an overall objective of the subject invention to produce a resultant image in which the graininess is minimized, smoothness is enhanced and the intended colors are accurately reproduced. Related methods have been proposed for error diffusion and screening in U.S. Pat. No. 6,072,591 and in U.S. Pat. No. 5,631,748 to Harrington, and in the publication "Color Stochastic Screening with Smoothness Enhancement", by J. Shu, C. H. Li, H. Ancin, and A, Bhattarcharjya, IS&T's NIP13: 1997 International Conference on Digital Printing Technologies.
Another problem relates to the smooth reproduction of highlight regions which is a challenge for most halftone printers. A highlight region is typically a color which is fairly close to white, e.g., a pale sand or pale gray color. Bi-level halftoning for highlight regions is particularly susceptible to graininess problems. In order to reduce visibility of halftone textures in highlight regions, a number of printing technologies utilize multiple printing levels per colorant. This is achieved either by using light and dark inks or by using a small drop-size and allowing multiple drops per pixel (multi-level halftoning). The lighter inks/smaller drops reduce the amount of luminance variation produced by the printed dots and thus produce highlight regions that have less visible halftone texture than those produced with darker colorants or larger drops. For photo-quality inkjet printing, this is increasingly becoming the predominant mode of printing as compared to bi-level halftoning and has been a strong driver of the evolution of inkjet printing technology.
While multi-level halftoning offers an inherent benefit over bi-level halftoning in reducing luminance variation in the highlights, the halftone texture visibility is still strongly influenced by the interactions between the different printed separations. Halftoning the different separations using the same halftone screen in a "dot-on-dot" configuration gives rise to the largest possible variation in luminance and therefore the most visible halftone textures. The more typical configuration of independent halftone screens for the different separations performs better but still exercises only limited control over inter-separation overlap.
Accordingly, there is a need for a halftoning algorithm for multi-level halftoning that utilizes a single halftone screen but achieves improved control of the interaction between halftone separations by utilizing a successive-filling algorithm for multi-level halftoning. The algorithm should give rise to smoother halftone textures and better ink dispersion than what is achieved with don-on-dot or independent screens

Color halftoning using a multi-level successive-filling halftone screening algorithm


A substantial reduction in the foreign particulate matter contamination on surfaces, such as the surfaces of semiconductor wafers, is achieved by treating the surfaces with a solution comprising a strong acid and a very small amount of a fluorine-containing compound. A preferred method employs a solution containing sulfuric acid, hydrogen peroxide and a very small amount of hydrofluoric acid, which is effective in reducing foreign particulate matter contamination, without significant etching, of the surface being treated.

1. Technical Field
This invention relates to the cleaning of surfaces, and, more particularly, to an improved method of reducing foreign particulate matter on surfaces of semiconductor wafers.
2. Description of the Prior Art
In the manufacture of semiconductor devices, cleaning steps are performed before or after various steps to remove foreign contaminants or impurities from the surfaces of semiconductor wafers. For example, wafers are commonly polished with abrasive slurries to produce smooth, polished surfaces; after polishing, it is necessary to remove the slurry and other surface contaminants from the wafers. Removal of foreign particulate matter, such as metallics and organic contaminants, is also required prior to high temperature processing steps, such as diffusion, thermal oxidation and epitaxial growth; otherwise, these impurities can adversely affect surface stability, reliability, electrical performance and production yield of devices. Cleaning steps are also commonly carried out after stripping photoresist materials from the surfaces of wafers and following etching steps.
Various techniques are used to clean foreign particulate matter from the surfaces of semiconductor wafers, such as chemical removal, centrifugation, air-stream or water jet cleaning, mechanical scrubbing and so forth. One commonly used chemical cleaning solution contains sulfuric acid and hydrogen peroxide (see, for example, Kern, W., "Hydrogen Peroxide Solutions For Silicon Wafer Cleaning", RCA Engineer 28-4 (July/August, 1983), pp. 99-105), but that solution is somewhat limited in its foreign particulate matter removal effectiveness. Other methods employing various cleaning solutions are exemplified by the disclosures in the following: U.S. Pat. No. 4,261,791, issued to Schwartzman on Apr. 14, 1981; U.S. Pat. No. 4,711,256, issued to Kaiser on Dec. 8, 1987; and U.S. Pat. No. 4,828,751, issued to Kremer on May 9, 1989.

Reduction of foreign particulate matter on semiconductor wafers

International Business Machines Corporation


A retention system for securing a stage mirror to the wafer stage of a semiconductor manufacturing device includes at least one first bracket and at least one second bracket. The retention system rigidly secures the stage mirror to the wafer stage during movement of the wafer stage to reduce positional measurement errors. The at least one first bracket has a substantially planar first contact surface for engaging the reflective surface of the mirror. The first contact surface is a finished aluminum surface, which does not scratch the mirror surface. The at least one first bracket is formed with a gusset providing increased stiffness in the direction of movement of the wafer stage. The at least one second bracket includes an actuator for moving a substantially planar second contact surface into engagement with a rear surface of the mirror. In one embodiment, the actuator is a threaded fastener and the second contact surface is a finished polyimide resin tip. The actuator is securable in the position where the second contact surface engages the mirror. The first contact surface and the second contact surface apply opposing forces to the mirror along a substantially common line of action. The at least one second bracket further provides a flexible retention member engaging an upper surface of the mirror.

1. Field of the Invention
This invention relates to a retention system for a mirror and, more particularly, to a retention system for a stage mirror on the wafer stage of a projection exposure device for manufacturing semiconductor wafers using a photolithography process.
2. Description of the Related Art
Conventional devices for manufacturing integrated circuits utilize a photolithographic process to reproduce a circuit pattern from a reticle, or photomask, onto the surface of a wafer. In this process, radiant energy is transmitted through non-opaque portions of the reticle, through a projection exposure apparatus, and onto a surface of the wafer coated with photosensitized silicon or other semiconductor material. Conventional devices use visible and ultraviolet light as a radiant energy source. The portions of the wafer surface that are exposed to the light are cured. The uncured portion is then removed by an acid bath.
The resulting silicon layer is used to produce one layer of a multi-layered integrated circuit. A complete integrated circuit is formed by overlaying additional silicon layers on the existing layers. The overlay process involves recoating the wafer and repeating the exposure process using reticles with different circuit patterns.
The wafers used in this process contain multiple dies arranged in rows on the wafer surface. Each die is used to produce a separate integrated circuit. During manufacturing, a first circuit layer is formed on each die by reproducing the circuit pattern from the reticle on each die surface. Further circuit layers are formed by overlaying additional circuit patterns on the first circuit layer of each die.
In one conventional device, the wafer is mounted on the surface of a computer-controlled platform, or stage, which precisely positions the dies with respect to the projection exposure apparatus. After a die is exposed, the wafer stage sequentially moves the remaining dies into position for exposure. This device is known as a step-and-repeat exposure system, or a stepper.
Stepper devices use laser interferometers, which detect the position of a target, such as a stage mirror, to precisely determine and control the position of the wafer stage during manufacturing. It has been found that the stage mirror moves relative to the wafer stage during motion transients of the stage, such as stopping, starting, and directional changes. The motion of the stage mirror results in measurement errors, known as backstep errors, as the wafer stage moves dies into position for exposure, and alignment errors, known as overlay errors, as subsequent circuit layers are applied to the dies.
In order to reduce backstep and alignment errors, stainless steel holders have been used to secure the stage mirror on the wafer stage. These conventional holders each provide point contact with the mirror, with a first holder contacting the mirror""s reflective surface and a second holder contacting the mirror""s non-reflective, or rear surface. Point contact is provided by rounded contact elements. The contact element of the second holder is spring biased to hold it in contact with the mirror surface.
There are a number of problems associated with the conventional holders. First, the holders are not stiff enough to adequately restrain the mirror. As the wafer stage moves in a first direction, the holders flex, allowing the stage mirror to move in the opposite direction, leading to positional measurement errors. Stepper systems with the stainless steel holders have been unable to provide the positional tolerances required for the manufacturing of modern integrated circuits.
Further, the conventional holders have introduced several non-linear measurement errors for which the control computer cannot compensate. The contact point of the first holder has been found to scratch the mirror""s reflective surface, causing surface imperfections. The contact point then moves over the mirror""s surface in an erratic stick/slip fashion, introducing measurement inaccuracies.
Finally, the force from the contact point of the second holder has been found to be inadequate to prevent slippage of the mirror relative to the wafer stage. The use of stronger springs to increase the biasing force of this contact point merely increases the deflection of the first holder, while not reducing the slippage of the mirror.
The advantages and purposes of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages and purposes of the invention will be realized and attained by the elements and combinations particularly pointed out in the appended claims.
To attain the advantages and consistent with the principles of the invention, as embodied and broadly described herein, a first aspect of the invention is a retention system for securing a mirror to a mounting surface of a wafer stage movable along an axis, wherein the mirror includes a substantially planar reflective surface, a rear surface, and an exposed surface, and wherein the reflective surface is substantially perpendicular to the axis. The retention system includes at least one first bracket adapted to engage the wafer stage and the mirror to restrain motion of the mirror relative to the wafer stage in at least a direction parallel to the axis, the at least one first bracket comprising a substantially planar contact surface adapted to engage a first one of the reflective surface and the rear surface of the mirror, and at least one second bracket adapted to engage the wafer stage and the mirror to restrain motion of the mirror relative to the wafer stage in at least a direction parallel to the axis, the at least one second bracket comprising a substantially planar contact surface adapted to engage a second one of the reflective surface and the rear surface of the mirror.
In another aspect, the invention provides a retention system including a platform movable along an axis, the platform including a mounting surface, a detection member disposed on the mounting surface, the detection member including an upper surface, a lower surface, a forward surface, and a rear surface, wherein the forward surface is substantially planar and substantially perpendicular to the axis, at least one first bracket engaging the platform and the detection member to restrain motion of the detection member relative to the platform in at least a direction parallel to the axis, the at least one first bracket comprising a first contact surface engaging one of the forward surface and the rear surface of the detection member, and at least one second bracket engaging the platform and the detection member to restrain motion of the detection member relative to the platform in at least a direction parallel to the axis, the at least one second bracket comprising a second contact surface engaging the other of the forward surface and the rear surface of the detection member.
In a further aspect, the invention provides a method of securing a mirror to a mounting surface of a wafer stage movable along an axis, the method including providing a mirror including a substantially planar reflective surface, a rear surface, and an exposed surface, wherein the reflective surface is substantially perpendicular to the axis, engaging at least one first bracket with the wafer stage and the reflective surface to restrain motion of the mirror relative to the wafer stage in at least a direction substantially parallel to the axis, and engaging at least one second bracket with the wafer stage and the rear surface to restrain motion of the mirror relative to the wafer stage in at least a direction substantially parallel to the axis.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. Additional advantages will be set forth in the description which follows, and in part will be understood from the description, or may be learned by practice of the invention. The advantages and purposes may be obtained by means of the combinations set forth in the attached claims.


A flash memory device comprises first and second mat structures connected to respective first and second high voltage lines, and a switch circuit connected between the first and second high voltage lines. The switch circuit supplies a program voltage from the first high voltage line to the second high voltage line during a first program operation of the flash memory device, and then supplies a voltage from the second high voltage line to the first high voltage line during a second program operation.

1. Field of the Invention
Embodiments of the present invention relate generally to semiconductor memory devices. More particularly, embodiments of the invention relate to a flash memory device and an associated recharge method.
A claim of priority is made to Korean Patent Application No. 10-2005-0087635, filed on Sep. 21, 2005, the disclosure of which is hereby incorporated by reference in its entirety.
2. Description of Related Art
Flash memory is a popular form of non-volatile memory included in a wide variety consumer and industrial electronic devices such as cellular phones, personal computers, cameras, portable memory sticks, and personal digital assistants, to name but a few. Several aspects of flash memory make it a particularly attractive option for portable electronic devices. These aspects include its high degree of integration, high operating speed, low power consumption, and high resistance to physical shock. An example of a flash memory device is disclosed in Japanese Laid-open Patent Application No. 2003-178590.
A flash memory device typically comprises a plurality of memory cells divided into a plurality of memory blocks. The memory cells can be programmed or read in units of individual memory cells, bytes, or words, but the memory cells must be erased an entire memory block at a time.
Most flash memory devices can be broadly classified into one of two categories, depending on the arrangement of memory cells within the devices. The two categories include NAND-type flash memory devices, and NOR-type flash memory devices. In general, NAND-type flash memory devices have faster program and erase times, a lower cost per bit, and a higher degree of integration than NOR flash memory devices. On the other hand, NOR-type flash memories tend to have faster read times. As a result, NAND-type flash memories are generally preferred over NOR-type flash memories for use as mass data storage units.
The memory cells of a NAND-type flash memory device are organized in a plurality of strings, wherein each string comprises a plurality of memory cells connected in series between a source line and a bit line. Such a string of memory cells constitutes a memory block of the NAND-type flash memory device. Because the memory cells in each memory block of a NAND-type flash memory device are connected in series, the memory cells must be accessed sequentially.
NAND-type flash memories are commonly designed to have a memory mat (MAT) structure including a plurality of memory blocks. In general, a memory mat structure is an arrangement of memory components designed to emulate a variety of memory structures. A memory mat structure typically has a fixed access width corresponding to a word width of a system that includes the memory mat structure. In addition, a NAND-type flash memory device can aggregate several memory mats to provide a wider access width. For example, if the access width of a single memory mat is 8 bits, two memory mats can be aggregated to provide a 16 bit access width.
FIG. 1 is a schematic block diagram illustrating a flash memory device 100 including two memory mats. In other words, flash memory device 100 has a two-MAT structure.
Referring to FIG. 1, flash memory device 100 includes a first MAT 110 and a second MAT 120. A word line decoder 130 is disposed between first MAT 110 and second MAT 120, and memory blocks 111 and 121 are respectively arranged in first MAT 110 and second MAT 120.
A first pump circuit 112 and a second pump circuit 122 provide respective first and second high voltages VPP1 and VPP2 to first MAT 110 and second MAT 120 through word line decoder 130. The respective levels of first and second high voltages VPP1 and VPP2 can be either a program voltage Vpgm, an erase voltage Verase, a read voltage Vread, or a pass voltage Vpass, depending on an operating mode of flash memory device 100.
FIG. 2 is a circuit diagram illustrating an example of first pump circuit 112, word line decoder 130, and memory block 111 shown in FIG. 1. Referring to FIG. 2, memory block 111 comprises "n" memory strings CS respectively connected to "n" bit lines BL0 through BLn−1. Each of memory strings CS comprises a string select transistor SST connected to a corresponding bitline, a plurality of memory cells M0 through M15, and a ground selection transistor GST. String select transistor SST, memory cells M0 through M15, and ground selection transistor GST are connected in series between the corresponding bitline and a common select line CSL.
The gates of memory cells M0 through M15 within each of memory strings CS are respectively connected to word lines WL0 through WL15. The gates of string selection transistors SST connecting memory strings CS to the respective bit lines BL0 through BLn−1 are connected to a string selection line SSL. The gates of ground selection transistors GST connecting memory strings CS to common source line CSL are connected to a ground selection line GSL.
Word line decoder 130 selectively activates string selection line SSL, ground selection line GSL, and word lines WL0 through WL15 of memory block 111. Word line decoder 130 comprises a decoder 132 receiving address signals ADDR and generating word line driving signals S0 through S15. Word line decoder further comprises a string selection voltage VSSL, a ground selection voltage VGSL, and a word line driver 134 for transferring word line driving signals S0 through S15, string selection voltage VSSL, and ground selection voltage VGSL to word lines WL0 through WL15, string selection line SSL, and ground selection line GSL.
Decoder 132 decodes address signals ADDR, and provides corresponding driving voltages to string selection line SSL, word lines WL0 through WL15, and ground selection line GSL. For example, decoder 132 provides program voltage Vpgm, erase voltage Verase, read voltage Vread, and pass voltage Vpass to string selection line SSL, word lines WL0 through WL15, and ground selection line GSL in a program operation, an erase operation, and a read operation, respectively.
Word line driver 134 includes high voltage pass transistors SN, WN0 through WN15, GN, and CN, for respectively applying string selection voltage VSSL, word line driving signals S0 through S15, ground selection voltage VGSL, and common source line voltage VCSL, to string selection line SSL, word lines WL0 through WL15, ground selection line GSL, and common source line CSL. First high voltage VPP1 output from first pump circuit 112 is applied to a block word line BLKWL in which gates of high voltage pass transistors SN, WN0 through WN15, GN, and CN are connected to each other.
First pump circuit 112 generates first high voltage VPP1 by a charge pumping operation when a pumping clock signal is applied. First high voltage VPP1 generated by first pump circuit 112 is provided to block word line BLKWL.
In the program operation, program voltage Vpgm is applied to an enabled word line, for example, to a first word line WL0, and pass voltage Vpass is applied to remaining word lines WL1 through WL15. In order to drive first word line WL0 using program voltage Vpgm provided by decoder 132, program voltage Vpgm is applied as a word line driving signal S0, and first high voltage VPP1 is applied to block word line BLKWL, so that pass transistor WN0 is turned on.
Program voltage Vpgm increases in proportion to the number of programmings and is generally between 15 V and 20 V. In order to transfer program voltage Vpgm without a voltage drop, first high voltage VPP1 is higher than program voltage Vpgm by a threshold voltage Vth of high voltage pass transistor WN0.
FIG. 3 is a graph plotting first high voltage VPP1 and second high voltage VPP2 when flash memory device 100 operates.
Referring to FIG. 3, first high voltage VPP1 rises to 20V during an interval TA when a program operation is performed and falls to about 4.5 V during an interval TB when a read operation is performed. Thereafter, in an interval TC, when another program operation is performed, first pump circuit 112 performs a pumping operation to raise first high voltage VPP1 to about 20 V.
If the pumping operation is repeatedly performed, power consumption of flash memory device 100 increases. Furthermore, due to the repeated pumping operations, a noise characteristic of the flash memory device 100 deteriorates. Accordingly, the flash memory device 100 is not suitable to install in various devices such as mobile phones.

Flash memory device and associated recharge method


A method and system of producing a three-dimensional object with an anti-counterfeiting measure uses a processor to access a data file including a plurality of parameters for producing a three-dimensional object, wherein the parameters comprise a plurality of structural parameters. The processor may also cause a three dimensional printing device to form the three dimensional object that exhibits the structural parameters by identifying a build material, identifying at least one anti-counterfeiting measure that when included in the 3D object will prevent creation of a digital model of the three-dimensional object by causing the 3D object to obstruct a possible 3D scanning method, and causing the three dimensional printing device to form the three-dimensional object with the anti-counterfeiting measure using the build material.

Additive Layer Manufacturing (ALM), also commonly referred to as 3D printing, is a process of making three-dimensional (3D) objects from a digital file such as Computer-Aided Design (CAD) data. Combining 3D printing with 3D scanning also makes possible 3D copying, i.e., a process where first a 3D digital model of an object is made by 3D scanning of the object and then a 3D copy of the 3D object is made by 3D printing a copy of the digital model. While this technology can bring many benefits, the advent of low-cost 3D print manufacturing also may increase the potential for counterfeiting. 3D printing and 3D scanning technologies can make it easier for one person to reproduce an object that is of another person's design.
Various methods are used today to prevent counterfeiting and provide authentication. Seals, watermarks and holograms are designed to provide reasonable protection against counterfeiters. Bar codes, QR codes and RFID chips are used to identify and authenticate objects. And transparent objects, such as glass bottles, may have 3D symbols engraved on their surface and even embedded in them. The problem with most of these methods is that they are visible and therefore can be copied by many 3D printing systems. Thus, so can the objects they intend to protect.
Prior art methods also try to solve this problem by aiding in the enforcement of intellectual property rights. However, current intellectual property laws and protection mechanisms are only effective in enforcing and/or preventing individual sources of intellectual property theft. Such laws and protection mechanisms, however, may be less effective in enforcing and/or preventing distributed or multiple sources of intellectual property theft, as may be the case with individuals utilizing 3D printing technology to produce items that infringe protected or proprietary designs.
Finally, there exist no methods to prevent the scanning of a 3D object to develop a digital model of the 3D object.
This document describes methods and systems that are directed to at least some of the problems described above.

This patent is subject to a terminal disclaimer.

Anti-counterfeiting measures for three dimensional objects


A reusable slider stop member has a solid body shaped to fit over a tooth element in a slide fastener assembly. The solid body has a central through channel defined by a pair of parallel prongs which fit over a tooth element. Each prong has an internal shoulder that engages a portion of the tooth element to retain the stop in place. The stop may be removed without damaging the stop or the tooth element, thus permitting easy repair of slide fastener assembly components. The stop is installed by aligning the channel at a right angle to the axis of the array of tooth elements, pressing the stop partially onto the tooth element, twisting the stop into alignment with the array and pressing the stop fully onto the tooth element to engage the internal shoulder of the stop with the tooth element.

1. Technical Field
This disclosure relates to the installation and use of stops for slide fasteners, and particularly to such stops which are easily attached by hand to prevent the slider from being removed during or after installation of a slide fastener in an article such as a garment.
2. Background Art
The stop prevents the slider from being removed from the top of the slide fastener in the event the slide fastener is cut to a desired length. The present disclosure departs from conventional concepts and designs of the prior art, and in doing so provides a member which can be inserted by hand without the need of a special tool or time consuming procedure for securing the stop onto the slide fastener.


A bathtub of integral construction especially adapted for installation in a private residence has a sump bottom spaced a sufficient distance above the floor and an opening in the apron leading to the space beneath the sump. The sump bottom spacing and apron opening enable the positioning of a portion of the undercarriage of a mobile patient lift underneath the sump bottom so that the bather supported by the lift can be positioned directly above the sump. Accordingly, the bather, who may be an invalid or other seriously physically handicapped person, may be transferred to a residential style bathtub in his home without having to disembark the lift. The invention also includes methods of making the bathtubs and using them with the mobile patient lifts.

1. Field of the Invention
This invention relates to sanitary fixtures. Specifically, it relates to bathtubs and whirlpool type bathtubs of integral construction especially adapted for use in combination with a mobile patient lift by invalids or other physically handicapped persons.
2. Description of Related Art
Personal hygiene and hydrotherapy are important to the general health and recovery of invalids, other seriously physically handicapped patients, and generally physically weak or frail persons. Health care workers, such as nurses, hospital aides, nursing home staff, or home health aides, assist in transferring these patients from their beds to the bathtub or whirlpool using a mobile patient lift. Patient lifts and bathtubs have been designed so that it is unnecessary for the patient to disembark the lift before getting into the bathtub. The Arjo fixed height bathtub and Lift Hygiene Chair mobile patient lift is one example of a system that can be used in this manner. Both devices are available from Arjo Hospital Equipment AB of Sweden or Arjo Inc. of Morton Grove, Ill. Such bathtub/lift systems can reduce the risk that the patient will slip or fall during the transfer. They also reduce the risk of lower back injury or other serious occupational injury to the health care worker.
The Arjo mobile patient lift and bathtub are used in the following manner. The patient is placed on the chair-like patient support of the lift and wheeled to the side rather than the end of the bathtub. The patient sits sideways in the patient support so that he is facing an end of the bathtub, such as the drain end. The lift mechanism is actuated to raise the patient above the side wall of the bathtub. Once the side wall has been cleared, the lift is placed closer to the bathtub so that a portion of the lift's mobile undercarriage is positioned directly beneath the sump and the patient is directly above the sump.
This positioning is possible because the sump of the Arjo fixed height bathtub does not rest on the floor like a conventional residential style bathtub. Instead, the sump is supported from below by sturdy, exposed horizontal support beams and vertical posts. The horizontal beams are elevated a sufficient distance above the floor so that the support legs and front wheels of the undercarriage portion of the lift can easily be positioned below the sump. Once positioned above the sump, the patient and support are then together lowered into the sump. Following the bath or hydrotherapy, the process is reversed to return the patient to bed.
Delivery of health care in a hospital, nursing home, or other institutional setting is very expensive compared to recuperation or therapy at home. There is a continuing effort to reduce health care costs by discharging patients from the hospital to their homes as soon as possible. For those invalids who can otherwise be cared for at home rather than in a hospital or other institution, bathing and/or hydrotherapy present a serious impediment to health care cost reduction: Most residential bathrooms are either too small to accommodate the bathtubs adapted for use with a mobile patient lift or patients are reluctant to abandon their stylish, colorful, and aesthetically pleasing residential style bathtubs for a more expensive bathtub having an institutional appearance. These residential style bathtubs and whirlpool type bathtubs do not accommodate the positioning of the undercarriage of the lift underneath the sump bottom so that the patient can be positioned above the sump.
The prior art describes various solutions to the problem of transferring an invalid into a bathtub or whirlpool, but none is directed to a residential rather than institutional style bathtub especially adapted for use with a mobile patient lift in a typical residential bathroom of limited size.
U.S. Pat. No. 3,457,569 to Von Ardenne et al., "Lifting Device for Lifting a Patient Treated in a Bathtub," describes a front-loading lift with a mobile undercarriage adapted to fit under the end, rather than the side, of a tub. Such an arrangement would require a very wide bathroom. Furthermore, the bathtub is not adapted for use of a side-loading lift such as the Arjo lift describe above.
U.S. Pat. No. 3,889,304 to Loren, "Bathing Device for Invalided Person" describes a patient lift and an institutional style bathtub. The patient lift is not mobile. Instead, it is attached to the bathtub.
U.S. Pat. No. 4,211,216 to Burgess et al., "Whirlpool Bath," describes raising a whirlpool bathtub above the floor level onto a recessed steel base. The 83/4 in. vertical clearance provided by the base provides a channel beneath the tub on three sides allowing a front-loading type mobile lift to be moved directly underneath the end rather than the side of the tub. Accordingly, as with the Von Ardenne invention, the bathroom must be quite large to accommodate positioning the large front-loading type mobile lift adjacent the end of the bathtub. The entire tub structure rests on the base by means of a plurality of I-beams which traverse the narrower dimension of the base. The Burgess invention is specifically designed for use in the hospital or institutional setting. The Burgess whirlpool does not resemble a whirlpool that one would expect to be accepted in a residential environment in part because it rests on an elevated and recessed steel base rather than directly on the floor.
U.S. Pat. No. 5,338,501 to Marsilio describes a molded bathtub having an apron which terminates above, below, or at about the level of the lowest level of the reservoir or sump. U.S. Pat. No. 4,664,982 to Genovese et al., "Multi-Layer Composite Structure," shows an enameled-steel bathtub having an apron which terminates at a level below the lowest level of the sump, but the patent does not describe or suggest any benefit in having this configuration. It does not describe how far below the lowest level of the sump the apron should terminate.
U.S. Pat. No. 5,343,575 to Cartwright, "Portable Bathing Unit," describes a molded bathtub mounted on a portable frame having casters. Rather than transporting the bedridden patient to the bath, this patent describes bringing the portable bath to the vicinity of the patient. The patient is transferred to the bath using a mobile patient hoist. The casters elevate the bathtub's frame high enough above the floor to permit the legs of the mobile patient hoist to pass underneath. The patent notes that conventional bathtubs typically are not elevated and, hence, do not allow the legs of the patient hoist to pass underneath.
There continues to be a need for sanitary fixtures, e.g., bathtubs and whirlpools, that resemble conventional, floor mounted fixtures of integral construction which are adapted for use with a mobile patient lift in the bathroom of the patient's home.

Sanitary fixtures for use with a mobile patient lift


A switchable ratchet freewheel, under load, for multiple-gear hubs on bicycles includes a bolted pawl, a drive, a switch bush, as well as a switch ring. The switch ring, which has a positive-fit connection to the pawl, can either be lifted by a bulge on the switch bush, which acts in concert with an incline on a switch nose, provided that a small or no turning moment is conveyed, or by recesses with end faces and timing edges, which act in concert with a run-up incline on the recesses, whereby the recess enters into a short positive-fit connection with the segment of the switch nose that faces radially inward, provided that higher turning moments are present. In case the pawl is not lifted immediately, by means of the bulge acting in concert with the incline, this results in the positive fit of the recess with the switch nose, which reliably disengages the pawl bond when the run-up incline acts in concert with the timing edge.

1. Field of the Invention
The present invention relates generally to a switchable ratchet freewheel for multiple-gear hubs for bicycles, including at least one pawl at the end face of a drive. The pawl is pivoted on a bolt that runs parallel to the hub axis. The switchable ratchet freewheel also includes a switch ring with pawl pockets for accommodating a catch nose of the pawl and a switch bush that is movable to and fro in the direction of engagement, which switch bush can have a make-and-break contact with a switch nose that is formed on the pawl.
2. Background Information
With German Laid Open Patent Application No. 29 37 126 a control mechanism for a catch pawl with a switch hub for a bicycle is described. A pawl control link that can be slid against a catch pawl in the axial direction is shown, whereby the catch pawl shows an incline. The pawl control link is, by means of an actuating link, axially movable but placed so that it is safe against rotation. A slanted incline on the pawl control link, matching the incline of the pawl, is equipped with pockets which allow the actuating link to move the pawl control link, at certain sections, a little further in the direction of the catch pawl. The transitions of the pockets in the pawl control link shall cause the transition of the catch pawl from the catch position to the rest position to be faster and speedier. A modulating force can be generated for the catch pawl, corresponding to the incline of the pocket vis-a-vis the incline of the catch pawl. However, should the catch force be even higher with an engaged catch pawl, the pawl control link and with it the actuating link are rejected and moved back opposite the control direction. In order to avoid such motion, the present invention has created the possibility that a switch bush, corresponding to the pawl control link, can no longer move axially against a pawl but rather under the pawl with a timing edge. Such an arrangement ensures that the pawl, by means of recesses and timing edges, can also be lifted when a drive load exists that is considerably higher than the control force of the switch bush.
Furthermore, with German Patent No. 44 15 266.3 A1, which corresponds to U.S. Pat. No. 5,556,354, a switching device for change-speed gears in multiple-gear hubs for bicycles is disclosed which includes several coaxially lined-up switching levels. Switch cam rods that are placed on the surface of the hub axis, coaxially to same, become swivelable around their axis by means of a cam control. Pawl couplings that are placed on a larger diameter in the change-speed gear of the hub can simultaneously, and in a coordinated manner, be controlled by the afore-mentioned cam control of the sun wheel. Such a switch clutch is realized with a switch sheath that is movable in the axial direction. The switch sheath shows an incline that can be slid under the pawls of the pawl coupling in order to lift them. The switch sheath shows an incline which moves a bolted pawl outward by lifting the part of the pawl that points radially inward, and thus disengages the pawl bond with a switch ring that is placed outside. A switch sheath with recesses, which slides under the pawl over the entire pawl width, is not suggested.

Switchable ratchet freewheel for multiple-gear hubs for bicycles


A zoom lens is provided and includes a first lens group, a second lens group, an aperture diaphragm, a third lens group, and a fourth lens group in order from the object side. The first lens group and the third lens group are fixed groups, and the second lens group and the fourth lens group are moving groups. The zoom lens has a right-angle prism in the first lens group and satisfies the specific conditions.

1. Field of the Invention
This invention relates to a zoom lens capable being used with a small-sized machine having an imaging function, particularly a digital still camera, a mobile telephone with a camera, a personal digital assistance (PDA), etc.
2. Description of Related Art
In recent years, further miniaturization of an imaging apparatus such as a digital still camera as the whole apparatus has been demanded with advance of miniaturization of an imaging device of a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), etc. Accordingly, slimming down of an imaging lens, particularly a zoom lens by shortening the entire length, etc. Hitherto, for a zoom lens having a variable power ratio of about ×3 of zoom lenses used with a digital still camera, etc., a zoom lens made up of three groups has been advantageous for shortening the entire length and has been widely used (Refer to JP-A-10-293253). Each lens group of the zoom lens is movable and although a length to some extent is required when used, the spacing between the groups is narrowed as much as possible when non-used, whereby slimming down is realized. In recent years, however, strong durability against shock of drop, etc., has been demanded for a digital still camera, etc., and the zoom lens made up of three groups described above has a structure wherein a lens barrel for supporting the moving lens groups when used pops up from the imaging apparatus main body and thus there is a limit for increasing the durability.
Then, as a configuration of a zoom lens to provide compatibility between slimming down and strong durability, in a four-group configuration of first positive, second negative, third positive and fourth positive groups, a right-angle prism is placed in the first lens group for bending the optical path approximately 90° at midpoint to form a refractive optical system, thereby shortening the length of the optical system in the thickness direction thereof (Refer to JP-A-8-248318, JP-A-2000-131610 and JP-A-2003-202500). In the configuration, the first lens group is fixed when zoomed and focused and thus a structure wherein the entire lens barrel can be housed in the imaging apparatus main body can be produced, making it possible to increase the durability as compared with the zoom lens made up of three groups described above.
However, the zoom lens described in JP-A-8-248318 is inappropriate for slimming down because the first lens group is large and the overall number of lenses is also large although the zoom lens has a large zoom ratio and a bright F value. The zoom lens described in JP-A-2000-131610 has a small number of lenses and a large angle of field at a wide angle end, but the first lens group is large and the right-angle prism has a low refractive index and is hard to totally reflect and thus reflecting coat becomes necessary on the reflection face of the right-angle prism, resulting in lowering of transmittance in the whole system and an increase in the cost. The zoom lens described in JP-A-2003-202500 involves various examples, which contain some examples of compact zoom lenses with a small number of lenses, but high-refractive index and high-dispersion material is used for the right-angle prism in every example and the transmittance on the short wavelength side of a visible light beam lowers. That is, in JP-A-2003-202500, a right-angle prism of a material with the refractive index at the d-line exceeding 1.8 and the Abbe number less than 30 is adopted as an example; under present circumstances, however, such a high-refractive index and high-dispersion material having sufficiently high transmittance does not exist and is not practical.


An electron emission display for improving brightness uniformity by compensating brightness deviation between respective elements. The electron emission display includes a display panel, a scan driver, a data driver, and a brightness compensator. The display panel includes a plurality of scan electrodes, a plurality of data electrodes, and a plurality of display elements respectively formed at crossing points of the scan electrodes and the data electrodes. The display elements respectively include an electron emitter. The scan driver applies a selection signal to the scan electrode. The data driver applies a data signal to the data electrode. The brightness compensator compensates brightness by changing the data signal when brightness deviation of the display elements is greater than a predetermined threshold value.

(a) Field of the Invention
The embodiments of the present invention relate to an electron emission display. More specifically, the embodiments relate to an electron emission display that is capable of compensating for brightness deviation.
(b) Description of the Related Art
Generally, a flat panel display (FDP) is a display device in which a seal is formed between two substrates to manufacture an airtight device and appropriate elements are arranged in the air tight device to display images. The importance of the FDP has been emphasized following the development of multimedia technologies. In response to this trend, various flat displays such as liquid crystal displays (LCDs), plasma display panels (PDPs), and electron emission displays have been developed and implemented.
In particular, because an electron emission display uses phosphorous emission caused by electron beams in a like manner to a cathode ray tube (CRT), it generates no image distortion, has low power consumption and has a high probability of forming the basis for a flat-type display that maintains the excellent characteristics of the CRT. In addition, this technology satisfies view angle, high-rate response, high resolution, fineness, and slimness criteria and accordingly, it has become the center of public attention as a next-generation display.
An electron emission display uses a cold cathode rather than a hot cathode, and such electron emission displays may be classified into field emission display (FED) devices, surface conduction emitting display (SCE) devices, and metal-insulator-metal (MIM) display devices.
The electron emission display concentrates a high electric field on an acute cathode, that is, the emitter, to emit electrons according to the quantum-mechanical tunnel effect. The electrons emitted by the emitter are accelerated by a voltage applied between the cathode electrode and the anode electrode and collide with the red, green and blue (RGB) phosphor layers formed on both the electrodes to emit light from the phosphors to display images.
However, emission of the electrons for each display element may change according to the density of the display elements, distance between the emitter and a gate electrode and an alignment of layers. That is, the emission of the electrons may change although the same signal is applied to the display elements. A difference in brightness occurs between the display elements and causes a deterioration in image quality.

Electron emission display and driving method


Systems and methods are provided for performing diagnostic testing for multiple motor drives operating in parallel. In one embodiment, the diagnostic testing may involve determining which of the multiple motor drives are in operation and communicating the active configuration of motor drives to testing circuitry. The testing circuitry generates an enable input signal transmitted to the transistor gates in each of the active motor drives. The testing circuitry also generates a power supply input signal transmitted to a DC to DC converter in each of the active motor drives. The responses to the enable input signal and the power supply input signal are measured to determine safety compliance.

The invention relates generally to the field of electrical power converters and inverters. More particularly, the invention relates to techniques for verifying that disable circuitry of parallel motor drives are functioning properly.
Large number of topographies and types of power conversion circuits are known and are in use. Many of these circuits rely upon inverter topologies for converting direct current (DC) power to control frequency alternating current (AC) power. In many topologies a rectifier or other converter is provided to receive incoming AC power, typically from the grid, and to convert the AC power to DC power that is applied to a DC bus used to feed the inverter circuitry. Such topologies are used in a variety of applications, such as for controlling the speed and operating characteristics of motors.
Motor drives utilizing inverter topologies often employ a single converter and single inverter coupled to one another by a single DC bus. Conventional inverters are formed by solid state switches provided in pairs and alternately switched between conducting and non-conducting states to provided desired output waveforms, typically of controlled frequency. Such topologies are adequate for many smaller applications, and may vary in size depending upon the power rating, frame size, voltage, and other specifications of the driven motor. However, for larger motors the components of such drives become proportionally large and expensive. It becomes attractive, then, to use alternative topologies in which multiple inverters are provided in parallel, with their outputs being joined to provide a common AC output to a load.
Such parallel inverter applications pose unique difficulties. For example, in certain circumstances it may be necessary to disable the motor drives. However, in some cases, decoupling one motor drive may affect the power delivered to parallel motor drives or to other motor drive circuitry that may be useful even though power is not being delivered to the load. Therefore, it may be useful in some circumstances to disable certain circuitry within the motor drive that will prevent the motor drive from outputting power to the load while maintaining the operability of certain control functions or other parallel motor drives in the system. In this way, useful functions of the power module may still be used while the output power to the load is disabled. Additionally, other motor drives operating in parallel may not be affected by the decoupling of one motor drive in the system. In these and other situations, it may be useful and even advisable to disable (e.g., shut down) one or more paralleled motor drives when certain unwanted conditions arise.
Moreover, in many cases it would be very useful to provide techniques to verify that the shutdown circuitry will operate properly when engaged. For example, a verification circuit may be used to periodically test the shutdown circuitry. The shutdown test may, however, tend to stress the power module circuitry or the load device, possibly leading to device failure. For pulsed motor drives, for example, rapid interruption and re-initiation of a pulse train powering the load can cause high potential differences within and between phase conductors that can lead to degradation of insulating systems, and eventually to failure of the motor or other system component. Also, interruption of actual drive power to a motor during such verification tests is generally undesirable. It may be advantageous, therefore, to provide a less disruptive system and method of testing a shutdown circuitry which may be used in a parallel motor drive system. To date, however, reliable disable-verification techniques for parallel motor drives that do not perturb the normal operation of the drive circuitry have yet to be developed or proposed.

Parallel motor drive disable verification system and method


The selectivity of an olefin epoxidation catalyzed by a noble metal-modified titanium or vanadium zeolite is greatly enhanced by the addition of a nitrogen compound to the reaction mixture. The epoxidation utilizes hydrogen and oxygen in addition to the olefin.

Epoxides constitute an important class of chemical intermediates useful for the preparation of polyether polyols, glycols, glycol ethers, surfactants, functional fluids, fuel additives and the like. Many different methods for synthesizing epoxides from the corresponding olefins have been described in the literature. A Japanese patent application assigned to the Tosoh Corporation and published in 1992 (Kokai No. 4-352771) proposed making propylene oxide by reacting propylene, hydrogen and oxygen using a catalyst comprising a Group VIII metal and a crystalline titanosilicate. Improvements to or variations of this basic process were subsequently described in the following published patent applications: WO 97/25143, DE 19600709, WO 96/02323, WO 97/47386, WO 97/31711, JP H8-269030, and JP H8-269029.
As with any chemical process, it would be desirable to attain still further improvements in epoxidation methods of this type. In particular, increasing the selectivity to epoxide and extending the useful life of the catalyst would significantly enhance the commercial potential of such methods. Using the reaction conditions and catalysts described in the literature, for example, hydrogenation of the olefin to the corresponding saturated hydrocarbon competes with the desired epoxidation reaction. The discovery of more effective ways of suppressing this side-reaction would be highly advantageous.


A tree harvester, suitable for harvesting small trees in row(s) as a source of biomass, has a harvesting head with a chipper drum and complementary anvil. A pick-up front has at least one spiral and guide member, such as a guide rail or counter-rotating spiral, to maintain a tree in a substantially vertical position when, and after, its stem is cut by a base cutter. The pick-up front has a support plate or conveyor, which co-operates with the at least one spiral or guide member pair, to convey the tree to a location about the chipper drum, for engagement by at least one pair of nip rollers above the chipper drum, while maintaining the tree in the substantially vertical position. The, or each, pair of nip rollers feeds the tree downwardly (and rearwardly) to the chipper drum, while still maintaining the tree in the substantially vertical position, for conversion to biomass, such as woodchips.

1. Field of the Invention
THIS INVENTION relates to tree harvesters.
The invention particularly relates, but is not limited to, tree harvesters suitable for harvesting shrubs, coppice or sapling trees, where such trees are planted at preferably regular spacings in rows.
2. Dictionary
The term "small trees" shall be used throughout the specification to describe shrubs and trees which have either a single-stemmed sapling form; or a plurality of coppice stems extending generally upwards from a tree stump or lignotuber; and by example, includes trees of the Eucalyptus and Acacia genera indigenous to Australia; and of the Salix and Populus genera indigenous to Europe and North America.
The term "in a substantially vertical position" will be used throughout the specification to indicate that a stem of a tree is inclined at an angle (preferably) no more than 30° to the vertical Z axis.
3. Prior Art
It has been proposed, in Australia, to grow trees of the Eucalyptus and Acacia genera as an ecologically-based answer to mankind's problems.
As the Eucalyptus and Acacia genera are fast-growing, their biomass can be used as a "renewable" source of energy, as the trees can be harvested every 2-6 years.
The second benefit of planting these trees is that some of the trees within the genera are salt tolerant and can be planted in areas, e.g., in Western Australia, where increased salinity levels have retarded the growing of other crops. The trees can also assist in lowering the water table, thereby reducing increases in the salinity levels near the soil surface.
Furthermore, they will take up CO2 gas from the atmosphere; and thereby assist the fight against global-warming.
The one disincentive to the proposal has been the ability to economically harvest the trees and transport the biomass from the tree growing areas to industry processors e.g., the electricity generating authorities, who will process the biomass to produce activated carbon or oil, and generate electricity.
It is not possible, with existing tree harvesters, to be able to achieve harvesting and transport costs that are economically viable.
In Europe, forage harvesters/maize harvesters/corn harvesters, e.g., of the types sold under the "Claas", "Krone", "New Holland" and "John Deere" Trade Marks have been modified to harvest certain trees. An example of such a "PRIOR ART" modified harvester will be hereinafter described with reference to FIGS. 1 to 3 of the accompanying drawings. These modified harvesters, however, have only been used to harvest European deciduous tree species, which generally have small-diameter, straight stems, and which are only harvested after they have dropped their leaves.

Abstract: The harvester may have two-or-more of the harvester heads arranged side-by-side to enable trees in adjacent rows to be harvested.


A rigid-flex circuit board system that can be manufactured using less expensive and more reliable rigid circuit board methods and equipment, and can maintain rigidity and dimensional stability until the time when it is first desired to flex.

This invention relates to providing a rigid-flex circuit board system which can be produced more efficiently and has greater functionality than prior art rigid-flex circuit boards. In the past, manufacturing rigid flex circuit boards has been problematic. Many factors, difficult to control given current manufacturing techniques, result in high scrap rates (circuit boards that do not work). For example, in the past, it has been troublesome to align flexible printed circuit layers with rigid printed circuit layers since the flexible printed circuit layers are not dimensionally stable (the flexible portions stretch, warp, shrink, etc.). This dimensional instability introduces a significant degree of variability in the manufacturing process. On a rigid printed circuit board, the location of the traces, and the pads for drilling and mounting components, etc. can be located with great reliability. Rigid board manufacturing processes can typically rely on determining the locations of the traces and pads etc. from registering just a couple points on the rigid board. With flexible printed circuit boards, locations of traces and pads cannot be as reliably mapped and registered since the flexibility results in the traces and pads etc., shifting by variable amounts. As a result, when flexible printed circuit layers are laminated to rigid circuit boards the connections between the two layers (at the interface) may not be aligned properly throughout due to the inconsistencies caused by dimensional instability of the flexible layer (with the result that the circuit board will not work properly, and must be scrapped, which is wasteful and expensive). In order to increase reliability (and reduce scrap) in manufacturing rigid-flex circuit boards, more expensive machinery and more complicated processes are used (than for manufacturing standard rigid boards). In the past, those attempting to reduce scrap, utilizing available manufacturing techniques, have also sacrificed the number and density of connections between the rigid and flexible layers, since these connections have been problematic (for the above reasons). However, as is well known in the industry, achieving higher densities can have many benefits (such as, for example, reduced size, reduced energy consumption, increased speed, etc.).
Further, even if the flexible layers are successfully connected to the rigid layers, later manufacturing steps are often still troublesome (and more expensive than standard rigid board manufacturing) as a result of the dimensional instability (variable stretching) introduced by the flexible portions. For example, reliability in soldering components to a rigid-flex board may be reduced due dimensional instability. Any fabrication and component assembly process involving handling the rigid-flex boards may be complicated due to portions of the board "flopping around" etc.
In the past (since mechanical support is needed during the assembly process of placing components, reflow of the solder process, and for installation in the housing, etc.) stiffeners (without conductive layers and without electrical connections/function) have been added to flex layers to provide such mechanical support. Also, in the past, manufacturing flexible circuits has been complicated by the need to use stabilization frames and/or rigid leaders and/or specialty plating racks in order to provide support for flexible portions of circuit boards during the manufacturing process. These methods add complexity, cost and increased scrap rates, to the manufacturing process.
These are just a few of the many complications that make manufacturing and manipulating flexible and rigid-flex circuit boards more difficult and expensive than standard rigid boards.


A photographing apparatus having an anti-vibration function includes a vibration detecting unit for detecting a vibration of the photographing apparatus, a reference value calculating unit for calculating a reference value of an output of the vibration detecting unit, and a focusing unit for adjusting a focal position of a photographing image. The apparatus also includes a focusing operation stopping unit for stopping an operation of the focusing unit and a reference value calculation stopping unit for stopping the calculation of the reference value by the reference value calculating unit by detecting the operation of the focusing operation stopping unit.

1. Field of the Invention
The present invention relates generally to a photographing apparatus having an anti-vibration function, which incorporates a function to correct a vibration derived from a camera shake or the like of a photographer and, more particularly, to a photographing apparatus having an anti-vibration function, the apparatus being capable of exhibiting the anti-vibration function in a predetermined state even when the photographer intentionally performs a framing operation in which the photographing is effected by changing a photographing angle after being focused.
2. Related Background Art
In a recent photographing apparatus, e.g., a camera with an auto exposure (AE) mechanism, the autofocus (AF) mechanism and other respective elements are automated at a high level. A highly-functionalized element is a function to correct image blur derived from a camera shake, etc. which is caused when photography is conducted while holding the camera with hands. A variety of proposals are made.
That is, in this type of camera, there have hitherto been proposed a variety of vibration preventing devices each having a vibration correctable construction such that, for the purpose of correcting the image blur produced by camera shake, especially by tilting the camera, each speed sensor serving as a vibration detecting device detects the camera shake and the vibration, and a photographing lens system or a part of this photographing lens system serving as a principal optical system is shift-driven in a direction orthogonal to the optical axis in accordance with a result of the detection thereof.
Then, in the camera having such an anti-vibration function, the photographing lens system or some lens elements thereof are movably controlled as a vibration correction optical system, thereby obviating the image blur. Even when exposed at a shutter speed slower than that of ordinary photographing, it is possible to take a photo in a state where no image blur is caused.
In addition, this type of camera, a focus lock is used during preparation for photographing. And it may happen that the exposure operation is often performed after the shaking of the camera for changing the photographing angle. The detected vibration signal is influenced by the movement for changing the visual angle, resulting in a problem such that an anti-vibration accuracy can not be secured when performing the photographing exposure.
For obviating this problem, for example, Japanese Patent Application Laid-Open No. 5-142615 discloses a construction in which there is determined whether or not it is the time when photography is being conducted in relation to the visual angle changing operation. If this is determined as the visual angle changing operation, the vibration is corrected by applying a compensation to vibration detection signal.
According to the prior art disclosed in Japanese Patent Application Laid-Open No. 5-142615, however, it is difficult to determine whether it is the visual angle changing operation or not. Further, in the case of determining that it is the visual angle changing operation, complicated control has to be done. A burden is imposed on a CPU mounted in the camera, and, for effecting the processing at a high speed, a high-performance CPU has to be employed. There arises the problem in which this leads to an increase in costs for the camera as a whole.
Also, an angular speed sensor is the dominant vibration detecting sensor used for the anti-vibration function in the above-mentioned camera, etc. In the case of using such an angular speed sensor, however, a sensor output when the vibration reference value is normalized (i.e., where the vibration is considered to be zero or where the angular speed is zero) becomes unstable due to a drift or the like. There is produced such an inconvenience that this directly worsens the vibration correcting accuracy.
As a countermeasure against this, for instance, Japanese Patent Application Laid-Open No. 4-211230 discloses a construction in which an average value (shift average value) of the sensor outputs for a predetermined time is obtained and employed as the output representing the zero vibration reference value to correct the sensor output.
In the apparatus disclosed in Japanese Patent Application Laid-Open No. 4-211230, however, when the average value of the sensor outputs for the predetermined time is set as a zero vibration reference value of the sensor output, the the following problems arise.
That is, with respect to a still camera, a great majority of photographers often intentionally take a photograph such that a framing operation is carried out after being set in an in-focus state by performing the focusing operation irrespective of the autofocusing and manual focusing, and thereafter the exposure is carried out.
Then, in such a case, it follows that a biasing vibration, due to the framing before the exposure, is mixed as a bias component in the vibration detection output for the predetermined time in the apparatus disclosed in Japanese Patent Application Laid-Open No. 4-211230. If the shift average value of the vibration detection outputs is employed as the output representing the zero vibration reference value, the problem is that the vibration detection output can not be accurately corrected.
For this reason, in this type of vibration correctable camera, it is desired that the bias component be prevented from being mixed in the vibration detection output during the framing operation described above and the vibration correcting accuracy be increased during the exposure.
For responding to such demands, the present applicant examined, in detail, the states of the vibration detection output and the camera operation that is performed by the photographer during the framing operation and found out the following points.
That is, Japanese Patent Application Laid-Open No. 3-237411 gives a statement that it is better to work the vibration correcting function during the vibrating operation and discloses a method of temporarily inhibiting the work of the vibration correcting function by the manipulation of the photographer. This intends to avoid the situation such that the framing becomes hard to perform due to the restraint on the manipulation, such as panning by the photographer, by the vibration correcting operation.
Then, Japanese Patent Application Laid-Open No. 3-237411 states that when performing the framing operation after being focalized by the focusing, there may be operated a switch for temporarily inhibiting the work of the vibration correcting function.
According to the Publication described above, however, there is no statement about the measures for improving the accuracy of the vibration correcting function at the time of the exposure, and therefore some measures capable of satisfying such a point are required.
Further, Japanese Patent Application Laid-Open No. 3-237411 states that a switch is provided in a lens barrel unit, and the work of the vibration correcting function is temporarily stopped by the photographer's manipulation of this switch.
In the camera disclosed in the above Publication, however, when trying to temporarily stop the work of the vibration correcting function, a vibration correcting operation stop switch has to be operated each time. This results in a problem of being troublesome and causes a lack of the operability.
In addition, in the conventional camera having the anti-vibration function as disclosed in Japanese Patent Application Laid-Open No. 3-237411, it is known that an AF lock function and an AE lock function are functions frequently employed when performing the framing operation.
Then, according to the conventional camera, these AF and AE lock functions are made to work by manipulating respective dedicated lock operation switches or by a changeover operating switch incorporating both of these functions.
According to the conventional camera having the anti-vibration function described above, however, the photographer temporarily stops the work of the image framing correcting function to work the AF or AE lock function. For this purpose, the photographer has to simultaneously manipulate the lens-side vibration correction stop switch and the above-mentioned body-side lock function operating switch. Accordingly, the problem inherent in such a conventional camera is that the operability is diminished, and the usability is poor.

Photographing apparatus having anti-vibration function