In a 3-D model window display device, depth (Z direction coordinate) quantities are given to all the windows to be displayed, so that they are regarded as arranged in a three-dimensional space. A virtual viewing point is also placed in the three-dimensional space. By projecting the windows onto a projection plane using the virtual viewing point on a real time basis, this device can display the windows which do not have depth quantities, whereby the user can perceive by intuition the overlapped state of the windows in the Z direction or the positional relationship in the virtual three-dimensional space.

1. Field of the Invention
The present invention relates to a window system for displaying a single or a plurality of windows overlapping one another on a display screen for display of characters and/or graphics under control of a computer and more particularly, to a window display system for presenting overlapped windows in such a form that a user can comprehend intuitively the overlapped window structure in a user-friendly manner.
2. Description of the Related Art
With respect to a so-called multi-window system for displaying a plurality of windows overlapping one another, there have already been suggested many systems which include (1) a system for presenting the front/back relationship of the windows in a user-friendly manner and (2) a system for depicting the front/back relationship of the windows efficiently.
The present invention is directed to systems of the above type (1). With regard to this type of system, that is, a system for presenting a multiplicity of windows overlapped (or arranged in a Z (depth) direction of a two-dimensional display screen) in a user-friendly manner on the display screen; there have been proposed systems which follow.
Japanese Laid-open Patent Application No. 2-250113 describes a graphic display for presenting graphic elements on a display screen stereoscopically or three-dimensionally by applying shades and shadows to the elements. In this graphic display, since a window frame is also stereoscopically depicted, this makes a boundary with another window more clear and thus the front/back relationship between the windows can be presented in a user-friendly manner.
In the graphic display, further, by applying shades and shadows also to graphic elements within the window and depicting stereoscopically shades and shadows cast by the window itself on a deeper (more distant) window, stereoscopical or three-dimensional array information on the overall display screen can be visually presented in the easy-to-understand manner.
Japanese Laid-open Patent Application No. 1-261722 discloses a multi-window display control system which puts all active windows that are in front of (shallower than) a window now of interest in their non-display state. This multi-window display control system can display only the window now of interest without changing the front/back relationship between the windows. Further, since the window front/back relationship is not changed, this also reduces the possibility of causing the user to get confused by the window front/back relationship.
In this way, the prior art systems presenting the window front/back relationship in a user-friendly manner have in common in that the display screen is arranged to effectively present a three-dimensional array of windows or the like.
The foregoing prior art systems however have problems which follow.
The first problem in the prior art is that, since the outer frames of the windows are contrasting in order to clearly distinguish between the inside and outside of the windows, the window boundary areas represented by the frames may become unnoticeable or unremarkable in some situations. More specifically, though the outer frames of the windows are contrasting by broadening the window frames, presenting them in striking color or stereoscopically, this method leads to the fact that the visual impact of the outer frames of the windows depends on the display content within the window frames. More in detail, the window frames become relatively unremarkable (1) when the graphic images within the window frames have a color tone design more visually noticeable than that of the window frames or (2) when the interior graphic images include a color tone or design very similar to that of the window frames. In this connection, since the graphic images within the window frames can be freely chose by the user, the possibility that the window frames become relatively unnoticeable cannot entirely be avoided.
The second problem in the foregoing prior art systems is that, even if the window frames can be sufficiently distinct, the window front/back (depth) relationship is presented simply by not displaying the hidden window areas of the other windows, for which reason it is difficult to recognize the front/back relationships among a multiplicity of windows.
That is, in the prior art systems, (1) it inevitably becomes hard to recognize the window front/back relationship when the window frames are unnoticeable, and in a certain display screen, (2) the window front/back relationship must be perceived on the basis of the window or the displayed contents (such as figures) of the window frames (for example, perception is such that, although the window is hidden by another window, its window area will be regarded by the user as actually existing). Accordingly, as the windows are overlapped in a more complicated way, it becomes more difficult to recognize the window front/back relationship.
In view of the above problems in the prior art, it is therefore an object of the present invention to provide a 3-D model window display system which, taking an array of windows in their depth direction (Z direction) into consideration, provides a dynamic change to the display coordinates, display scale factor, etc. of each window in response to a movement of a virtual viewing point operated by a user on a real time basis, thereby to give an impression to the user of the windows overlapping in a three-dimensional space. This allows the user to perceive intuitively the boundary areas of the windows or positional relationships therebetween and can improve the ease of use of the window system.


A display device is provided. The display device includes a display region. The display region has a plurality of pixels. Each of the plurality of pixels comprises a switching transistor having a gate electrically connected to a scanning line and controlling the input of an image signal provided from a signal line, a drive transistor input with the image signal through the switching transistor and controlling a current value based on the image signal, a display element having a first electrode electrically connected to the driving transistor and emitting light by a current supplied through the drive transistor, a storage capacitor having a first electrode electrically connected to a gate of the drive transistor, and a reset transistor connected between the first electrode of the display element and a reset line, and having a gate electrically connected to the scanning line.

A liquid crystal display device and an organic EL display device are exemplified as the flat panel display device. In these display devices, a display region in which a plurality of display elements are arranged in a matrix is arranged with a signal line group extending in a first direction and a scan line group extending in a second direction intersecting the first direction, and an image is displayed by individually controlling the signal line group and the scan line group.
A number of organic EL display devices include an initialization operation before writing an image signal in the next display frame following a certain display frame. Here, for example, the initialization operation includes the following operation: the operation state of each display element in the immediately preceding display frame is forcibly unified to a state in which all pixels are non-display state, and the operation state is prepared for the writing of a subsequent video signal. In addition, this initialization operation can be seen as a forcibly operation stopping the display when seen from the immediately preceding display frame. In addition, it is possible to include this initialization operation as a period for controlling an effective display period during the entire operation period of the display device (see Japanese Laid Open Patent Publication No. 2004-102294).

Display device and driving method for display device


A first current is supplied to a first primary winding of an ignition coil and a second current is supplied to a second primary winding of the ignition coil. A voltage is generated across a secondary winding of the ignition coil and an ignition spark current is generated at a spark plug coupled to the secondary winding. The ignition spark current is based upon the generated voltage and the sum of the first current and the second current.

Vehicular ignition systems typically operate when electrical current flows through a primary winding of an ignition coil and this current flow induces energy to be stored in a magnetic field associated with the coil. The inductance of the coil, the amount of supply current applied to the coil, and the dwell time of the coil (i.e., the time set aside to build the current in the primary winding of the coil) are some factors that determine the amount of energy that can be stored in the magnetic field of the coil.
The stored energy of the coil is released when the primary winding current is suddenly turned off and the released energy flows from the magnetic field as a secondary current in a secondary winding of the ignition coil. Due to the high turns ratio typically used in coils and the rapid collapse of the magnetic field in the coil, a spark is generated across a spark plug that is attached to the secondary winding of the coil.
Different types of coil configurations have been used in previous vehicular ignition systems. To take one example, "pencil" coils are a special type of coil that have relatively long and narrow dimensions and have been used, for instance, in motorcycle ignition systems. In pencil coil arrangements, electronic coil drivers are typically used to drive the coils and a separate coil (and driver) are used to drive each cylinder of the engine. The coil drivers are themselves typically controlled by an electronic control unit (ECU), which controls the current dwell time for each coil.
In many demanding applications (e.g., drag racing), it is often desirable to retrofit the system to increase the energy in the system to thereby provide a stronger spark than is normally provided. In attempting to achieve this result, some users replaced their older coils with newer coils having lower inductances thereby increasing the current in the coil and, consequently, the amount of energy that could be stored in the magnetic field associated with the coil. However, these approaches required that existing coil drivers and existing ECUs be able to handle the larger currents associated with the newer coils. Unfortunately, existing coil drivers and ECUs often were damaged or destroyed by these increased currents making it impractical or impossible to increase spark energy in existing systems to the levels desired.
Because of these problems, it was difficult or impossible to retrofit existing systems to provide for increased spark energy or other enhanced spark characteristics while at the same time protecting and preserving existing system components. This resulted in user frustration with these previous systems and the general inability to achieve the increased performance levels desired by users.

Multiple primary coil ignition system and method


A method for determining weight factors of antenna beams, the method comprising using at least one directional antenna beam implemented with an antenna array to establish a radio link, forming a radio cell with the antenna beam, dividing the radio cell into at least two different cells by dividing the antenna beam, selecting weight factors of antenna elements of the antenna array such that the antenna element specific sums of weight factors of a radio cell formed with the antenna array and corresponding weight factors of at least one, second radio cell formed with the same antenna array are at least substantially equal within predetermined limits in order to achieve a predetermined power balance between different antenna elements.

When adaptive antenna arrays are used, the basic principle is that radiation beams are narrow and they are directed as directly as possible at a desired receiver. Widely known methods of using adaptive antenna arrays can be divided into two main groups: radiation beams are directed at a receiver, or the most suitable beam is selected from various alternative beams. For a downlink transmission, a suitable beam is selected or the beam is turned on the basis of information obtained from the uplink. The reuse of frequencies can be made more efficient and the power of transmitters can be reduced, because, owing to the directivity of antenna beams, interference with other users diminishes.
In a digital system, the directing of antenna beams in the up-link is implemented by dividing a signal in baseband parts into I and Q branches and by multiplying in a complex manner (phase and amplitude) the signal of each antenna element by appropriate weighting coefficients, and then by summing up the output signals of all antenna elements. In this case, an adaptive antenna array comprises not only antennas but also a signal processor, which automatically adapts antenna beams by using a control algorithm so that in the downlink, it turns the antenna beams to a direction in which the strongest signal is measured in the uplink. The directivity of beams can also be implemented analogically by using fixed phasing circuits (Butler matrix) for generating orthogonal radiation beams in which the phase changes linearly antenna by antenna. The Bulter matrix is used to measure which beam receives most signal energy, i.e. in which beam the signal is the strongest, and this beam is selected for the transmission.
However, it is not always sufficient that a user-specific antenna beam is used for monitoring the location of the user as precisely as possible. Namely, the problem is that the number of those needing radio resources varies in the coverage area. A radio cell, where the number of those needing services can usually be covered, can temporarily become a so-called hot spot area with a lot of users in a relatively small area. To solve this problem, it has been suggested that an antenna beam, i.e. sector, formed with a fixed Bulter matrix is split into two beams. The method allows the operator to change azimuth angles by a step of 30 degrees, since 4 orthogonal beams, each having a coverage area of about 30 degrees, can typically be generated with a 4×4 Butler matrix. The method is called sector synthesis.
A problem with fixed-beam systems is, however, how to design power amplifiers, because, in the worst case, each power amplifier of an antenna array has different designs, which causes costs during planning and implementation phases. In digital beam forming, the problem with an attempt to have a power balance between different antenna elements is that compromises have to be made in order to optimize the width and side-lobe levels of antenna beams.

Data transmission method and arrangement


The presently claimed and disclosed inventive concept(s) contemplates a novel polymeric oral dosage form (transmucosal delivery vehicle) for delivery of pharmaceutical and nutriceutical bioactive agents to the mucosa and bloodstream of the intestine. The oral dosage form of the presently claimed and disclosed inventive concept(s) comprises a polymeric coating which encapsulates the bioactive agent and inhibits degradation and dissolution of the bioactive agent within the stomach and within the lumen of the intestine until after passing through the mucosal wall of the small and/or large intestine. The enzymatic degradation of the polymeric delivery vehicle containing the bioactive agent is substantially inhibited until after absorption of the polymeric delivery vehicle into blood vessels of the intestinal mucosa. It is a particular object of the presently claimed and disclosed inventive concept(s) to provide a new and improved method for enterically or intestinally encapsulating pharmaceutical and nutriceutical bioactive agent or agents for oral administration of the encapsulated bioactive agent or agents.

The presently claimed and disclosed inventive concept(s) relates generally to pharmaceutical and nutriceutical products, and, and more particularly to improved encapsulated pharmaceutical and nutriceutical bioactive agents and methods of their production and methods of their use.
It is often desirable for an orally consumed pharmaceutical or nutriceutical bioactive material to be absorbed into the bloodstream through the wall of the small intestine or large intestine. The delivery vehicle which contains the bioactive agent must be able to pass intact through the stomach and must remain intact in the lumen of the small intestine in order to be passed through the intestinal mucosa and deliver the bioactive agent into the blood stream. Enteric coatings are frequently used to encapsulate oral dosage forms to prevent damage to the active substance contained in the oral preparation by acids and enzymes in the stomach. Enteric coatings are used for example for preventing gastric enzymes from reacting with or destroying the active substance, preventing dilution of the active substance before it reaches the small intestine, ensuring that the active substance is not released until after the preparation has passed the stomach, and preventing damage to the bioactive agent because of the low pH in the stomach.
Enteric coatings can also be used for avoiding irritation of or damage to the mucous membrane of the stomach caused by substances contained in the oral preparation, and for counteracting or preventing formation or release of substances having an unpleasant odor or taste in the stomach. Finally, such coatings can be used for preventing nausea or vomiting on intake of oral preparations.
The lumen of the small intestine and the blood vasculature of the intestinal mucosa are ideal dissolution targets for a wide variety of bioactive pharmaceutical and nutriceutical compounds, presuming one is able to overcome its characteristics of impermeability through the intestinal wall. It is to providing such encapsulated pharmaceutical and nutriceutical bioactive materials for optimal delivery to and absorption into the small intestine that the present invention is directed.

Microencapsulated bioactive agents for oral delivery and methods of use thereof


The invention generally relates to devices for fastening a hernia mesh. The invention provides a surgical fastening device that includes a shaft with a fastener carrier disposed at least partially within the shaft, in which the carrier is configured to accept fasteners of a plurality of different sizes. Different sized fasteners can be preloaded in interchangeable carriers or even mixed together within a carrier in the fastening device. The device can deliver the fasteners to different depths in a patient's tissue.

If a person has a hernia, they may suffer from pain, organ dysfunction, bowel obstruction, or other complications. This occurs when an organ protrudes through the wall that normally contains it. Hernias can occur in a number of parts of the body, and occur commonly in the abdomen. For example, the peritoneum that lines the abdomen may push out through a weakened area of the abdominal wall to form a small balloon-like sac. This can allow a loop of intestine or abdominal tissue to push into the sac.
One method of hernia repair involves using a surgical procedure known as laparoscopy to cover the hernia with a prosthetic mesh and fix it in place with fasteners. The fasteners are typically either sutures or specialized tacks that are delivered by a fastening device configured to reach into the abdominal cavity through an incision.
A surgeon makes a small incision in the skin and inserts surgical implements as well as a laparoscope—a small telescope with a camera attached. The surgeon uses the laparoscope to study the hernia and surrounding tissue of the abdominal wall. Naturally, the thickness of the layers of the abdominal wall varies from person to person and even from place to place within a patient. For example, the layers of fat may be thick or thin depending on a person's physical fitness. Unfortunately, there is no established method or device that allows a surgeon to fix a hernia mesh with fasteners having different penetration depths or sizes to accommodate the variation in thickness of the abdominal wall.
What is particularly problematic is that the shortcomings of current methods are associated with a risk of complications and patient pain. If the abdominal muscle wall is too thick due to obesity, the fasteners will not penetrate deeply enough, and the hernia mesh will not be fixed in place successfully. If the wall is to thin, the length of the fasteners poses a significant risk of pain and complications. Fasteners for the hernia mesh that protrude deeply into a patient's tissue exacerbate the patient's post-operative pain.

This patent is subject to a terminal disclaimer.


The invention relates to security feature for identification documents, and in particular to A security feature, comprising a first covert layer comprising a first covert material that is not visible to a human eye under except under a first condition, the first covert layer further comprising a material constructed and arranged to produce, upon an attempted intrusion into any part of the security feature, a first effect that is visible at least under the first condition; an optically variable layer having first and second sides, the first side being disposed adjacent the first covert layer, the optically varying layer being constructed and arranged to cover at least a portion of the first covert layer; and a second covert layer disposed adjacent to the second side of the optically variable layer, the second covert layer being constructed and arranged to cover at least a portion of the optically variable layer, the second covert layer comprising a second covert material that is visible to the human eye only at a second condition.

Identification Documents
Identification documents (hereafter "ID documents") play a critical role in today's society. One example of an ID document is an identification card ("ID card"). ID documents are used on a daily basis—to prove identity, to verify age, to access a secure area, to evidence driving privileges, to cash a check, and so on. Airplane passengers are required to show an ID document during check in, security screening and prior to boarding their flight. In addition, because we live in an ever-evolving cashless society, ID documents are used to make payments, access an automated teller machine (ATM), debit an account, or make a payment, etc.
(For the purposes of this disclosure, ID documents are broadly defined herein, and include, e.g., credit cards, bank cards, phone cards, passports, driver's licenses, network access cards, employee badges, debit cards, security cards, visas, immigration documentation, national ID cards, citizenship cards, social security cards, security badges, certificates, identification cards or documents, voter registration cards, police ID cards, border crossing cards, legal instruments, security clearance badges and cards, gun permits, gift certificates or cards, membership cards or badges, etc., etc. Also, the terms "document," "card," "badge" and "documentation" are used interchangeably throughout this patent application.).
Many types of identification cards and documents, such as driving licenses, national or government identification cards, bank cards, credit cards, controlled access cards and smart cards, carry thereon certain items of information which relate to the identity of the bearer. Examples of such information include name, address, birth date, signature and photographic image; the cards or documents may in addition carry other variant data (i.e., data specific to a particular card or document, for example an employee number) and invariant data (i.e., data common to a large number of cards, for example the name of an employer). All of the cards described above will hereinafter be generically referred to as "ID documents".
As those skilled in the art know, ID documents such as drivers licenses can contain information such as a photographic image, a bar code (which may contain information specific to the person whose image appears in the photographic image, and/or information that is the same from ID document to ID document), variable personal information, such as an address, signature, and/or birthdate, biometric information associated with the person whose image appears in the photographic image (e.g., a fingerprint), a magnetic stripe (which, for example, can be on the a side of the ID document that is opposite the side with the photographic image), and various security features, such as a security pattern (for example, a printed pattern comprising a tightly printed pattern of finely divided printed and unprinted areas in close proximity to each other, such as a fine-line printed security pattern as is used in the printing of banknote paper, stock certificates, and the like).
An exemplary ID document can comprise a core layer (which can be pre-printed), such as a light-colored, opaque material (e.g., TESLIN (available from PPG Industries) or polyvinyl chloride (PVC) material). The core is laminated with a transparent material, such as clear PVC to form a so-called "card blank". Information, such as variable personal information (e.g., photographic information), is printed on the card blank using a method such as Dye Diffusion Thermal Transfer ("D2T2") printing (described further below and also described in commonly assigned U.S. Pat. No. 6,066,594, which is incorporated herein by reference in its entirety.) The information can, for example, comprise an indicium or indicia, such as the invariant or nonvarying information common to a large number of identification documents, for example the name and logo of the organization issuing the documents. The information may be formed by any known process capable of forming the indicium on the specific core material used.
To protect the information that is printed, an additional layer of transparent overlaminate can be coupled to the card blank and printed information, as is known by those skilled in the art. Illustrative examples of usable materials for overlaminates include biaxially oriented polyester or other optically clear durable plastic film.
In the production of images useful in the field of identification documentation, it may be desirable to embody into a document (such as an ID card, drivers license, passport or the like) data or indicia representative of the document issuer (e.g., an official seal, or the name or mark of a company or educational institution) and data or indicia representative of the document bearer (e.g., a photographic likeness, name or address). Typically, a pattern, logo or other distinctive marking representative of the document issuer will serve as a means of verifying the authenticity, genuineness or valid issuance of the document. A photographic likeness or other data or indicia personal to the bearer will validate the right of access to certain facilities or the prior authorization to engage in commercial transactions and activities.
Identification documents, such as ID cards, having printed background security patterns, designs or logos and identification data personal to the card bearer have been known and are described, for example, in U.S. Pat. No. 3,758,970, issued Sep. 18, 1973 to M. Annenberg; in Great Britain Pat. No. 1,472,581, issued to G. A. O. Gesellschaft Fur Automation Und Organisation mbH, published Mar. 10, 1976; in International Patent Application PCT/GB82/00150, published Nov. 25, 1982 as Publication No. WO 82/04149; in U.S. Pat. No. 4,653,775, issued Mar. 31, 1987 to T. Raphael, et al.; in U.S. Pat. No. 4,738,949, issued Apr. 19, 1988 to G. S. Sethi, et al.; and in U.S. Pat. No. 5,261,987, issued Nov. 16, 1993 to J. W. Luening, et al. All of the aforementioned documents are hereby incorporated by reference.
Printing Information onto ID Documents
The advent of commercial apparatus (printers) for producing dye images by thermal transfer has made relatively commonplace the production of color prints from electronic data acquired by a video camera. In general, this is accomplished by the acquisition of digital image information (electronic signals) representative of the red, green and blue content of an original, using color filters or other known means. Devices such as digital cameras, optical sensors, and scanners also can provide digital image information. The digital image information is utilized to print an image onto a data carrier. For example, information can be printed using a printer having a plurality of small heating elements (e.g., pins) for imagewise heating of each of a series of donor sheets (respectively, carrying diffuseable cyan, magenta and yellow dye). The donor sheets are brought into contact with an image-receiving element (which can, for example, be a substrate) which has a layer for receiving the dyes transferred imagewise from the donor sheets. Thermal dye transfer methods as aforesaid are known and described, for example, in U.S. Pat. No. 4,621,271, issued Nov. 4, 1986 to S. Brownstein and U.S. Pat. No. 5,024,989, issued Jun. 18, 1991 to Y. H. Chiang, et al. Each of these patents is hereby incorporated by reference.
Dye diffusion thermal transfer printing ("D2T2") and thermal transfer (also referred to as mass transfer printing) are two printing techniques that have been used to print information on identification cards. For example, D2T2 has been used to print images and pictures, and thermal transfer has been used to print text, bar codes, and single color graphics.
D2T2 is a thermal imaging technology that allows for the production of photographic quality images. In D2T2 printing, one or more thermally transferable dyes (e.g., cyan, yellow, and magenta) are transferred from a donor, such as a donor dye sheet or a set of panels (or ribbons) that are coated with a dye (e.g., cyan, magenta, yellow, black, etc.) to a receiver sheet (which could, for example, be part of an ID document) by the localized application of heat or pressure, via a stylus or thermal printhead at a discrete point. When the dyes are transferred to the receiver, the dyes diffuse into the sheet (or ID card substrate), where the dyes will chemically be bound to the substrate or, if provided, to a receptor coating. Typically, printing with successive color panels across the document creates an image in or on the document's surface. D2T2 can result in a very high printing quality, especially because the energy applied to the thermal printhead can vary to vary the dye density in the image pixels formed on the receiver, to produce a continuous tone image. D2T2 can have an increased cost as compared to other methods, however, because of the special dyes needed and the cost of D2T2 ribbons. Also, the quality of D2T2-printed image may depend at least on an ability of a mechanical printer system to accurately spatially register a printing sequence, e.g., yellow, magenta, cyan, and black.
Another thermal imaging technology is thermal or mass transfer printing. With mass transfer printing, a material to be deposited on a receiver (such as carbon black (referred to by the symbol "K")) is provided on a mass transfer donor medium. When localized heat is applied to the mass transfer donor medium, a portion (mass) of the material is physically transferred to the receiver, where it sits "on top of" the receiver. For example, mass transfer printing often is used to print text, bar codes, and monochrome images. Resin black mass transfer has been used to print grayscale pictures using a dithered gray scale, although the image can sometimes look coarser than an image produced using D2T2. However, mass transfer printing can sometimes be faster than D2T2, and faster printing can be desirable in some situations.
Printing of black ("K") can be accomplished using either D2T2 or mass transfer. For example, black monochrome "K" mass transfer ribbons include Kr (which designates a thermal transfer ribbon) and Kd (which designates dye diffusion).
Both D2T2 and thermal ink have been combined in a single ribbon, which is the well-known YMCK (Yellow-Magenta-Cyan-Black) ribbon (the letter "K" is used to designate the color black in the printing industry). Another panel containing a protectant ("P") or laminate (typically a clear panel) also can be added to the YMCK ribbon).
Manufacture and Printing Environments
Commercial systems for issuing ID documents are of two main types, namely so-called "central" issue (CI), and so-called "on-the-spot" or "over-the-counter" (OTC) issue.
CI type ID documents are not immediately provided to the bearer, but are later issued to the bearer from a central location. For example, in one type of CI environment, a bearer reports to a document station where data is collected, the data are forwarded to a central location where the card is produced, and the card is forwarded to the bearer, often by mail. Another illustrative example of a CI assembling process occurs in a setting where a driver passes a driving test, but then receives her license in the mail from a CI facility a short time later. Still another illustrative example of a CI assembling process occurs in a setting where a driver renews her license by mail or over the Internet, then receives a drivers license card through the mail.
In contrast, a CI assembling process is more of a bulk process facility, where many cards are produced in a centralized facility, one after another. (For example, picture a setting where a driver passes a driving test, but then receives her license in the mail from a CI facility a short time later. The CI facility may process thousands of cards in a continuous manner.).
Centrally issued identification documents can be produced from digitally stored information and generally comprise an opaque core material (also referred to as "substrate"), such as paper or plastic, sandwiched between two layers of clear plastic laminate, such as polyester, to protect the aforementioned items of information from wear, exposure to the elements and tampering. The materials used in such CI identification documents can offer the ultimate in durability. In addition, centrally issued digital identification documents generally offer a higher level of security than OTC identification documents because they offer the ability to pre-print the core of the central issue document with security features such as "micro-printing", ultra-violet security features, security indicia and other features currently unique to centrally issued identification documents.
In addition, a CI assembling process can be more of a bulk process facility, in which many cards are produced in a centralized facility, one after another. The CI facility may, for example, process thousands of cards in a continuous manner. Because the processing occurs in bulk, CI can have an increase in efficiency as compared to some OTC processes, especially those OTC processes that run intermittently. Thus, CI processes can sometimes have a lower cost per ID document, if a large volume of ID documents are manufactured.
In contrast to CI identification documents, OTC identification documents are issued immediately to a bearer who is present at a document-issuing station. An OTC assembling process provides an ID document "on-the-spot". (An illustrative example of an OTC assembling process is a Department of Motor Vehicles ("DMV") setting where a driver's license is issued to person, on the spot, after a successful exam.). In some instances, the very nature of the OTC assembling process results in small, sometimes compact, printing and card assemblers for printing the ID document. It will be appreciated that an OTC card issuing process is by its nature can be an intermittent—in comparison to a continuous—process.
OTC identification documents of the types mentioned above can take a number of forms, depending on cost and desired features. Some OTC ID documents comprise highly plasticized poly(vinyl chloride) or have a composite structure with polyester laminated to 0.5-2.0 mil (13-51 .mu.m) poly(vinyl chloride) film, which provides a suitable receiving layer for heat transferable dyes which form a photographic image, together with any variant or invariant data required for the identification of the bearer. These data are subsequently protected to varying degrees by clear, thin (0.125-0.250 mil, 3-6 .mu.m) overlay patches applied at the printhead, holographic hot stamp foils (0.125-0.250 mil 3-6 .mu.m), or a clear polyester laminate (0.5-10 mil, 13-254 .mu.m) supporting common security features. These last two types of protective foil or laminate sometimes are applied at a laminating station separate from the printhead. The choice of laminate dictates the degree of durability and security imparted to the system in protecting the image and other data.
UV Security Features in ID Documents
One response to the problem of counterfeiting ID documents has involved the integration of verification features that are difficult to copy by hand or by machine, or which are manufactured using secure and/or difficult to obtain materials. One such verification feature is the use in the card of a signature of the card's issuer or bearer. Other verification features have involved, for example, the use of watermarks, biometric information, microprinting, covert materials or media (e.g., ultraviolet (UV) inks, infrared (IR) inks, fluorescent materials, phosphorescent materials), optically varying images, fine line details, validation patterns or marking, and polarizing stripes. These verification features are integrated into an identification card in various ways and they may be visible or invisible (covert) in the finished card. If invisible, they can be detected by viewing the feature under conditions which render it visible. At least some of the verification features discussed above have been employed to help prevent and/or discourage counterfeiting.
Covert security features are those features whose presence is not visible to the user without the use of special tools (e.g., UV or IR lights, digital watermark readers) or knowledge. In many instances, a covert security feature is normally invisible to a user. Some technologies that involve invisible features require the use of specialized equipment, such as a detector or a device capable of reading digital watermarks. One type of covert security feature is the printing of information (images, designs, logos, patterns, text, etc.) in a material that is not visible under normal lighting conditions, but can be viewed using a special non-visible light source, such as an ultraviolet (UV) or infrared (IR) light source. Use of UV and/or IR security features can be advantageous because although the devices (for example, UV and/or IR light sources) required to see and use such features are commonly available at a reasonable cost, the ability to manufacture and/or copy at least some implementations of such features is far less common and can be very costly. UV and IR based covert security features thus can help deter counterfeiters because the features cannot be copied by copiers or scanners and are extremely difficult to manufacture without the requisite know-how, equipment, and materials.
For example, the assignee of the present invention has developed and marketed a proprietary product called PolaPrime-UV™. PolaPrime-UV™ is a type of security feature. One application of PolaPrime-UV™ is for full color photo quality printing of fixed (i.e., not variable data) fluorescent images. The artwork that can be printed using PolaPrime-UV™ includes many images that can be produced with a combination of red, green, and blue phosphors. Under the appropriate light (e.g., a light source capable of providing UV light), the effect seen when viewing an image printed with PolaPrime-UV™ is similar in appearance to a television screen in that the image is formed by emission of light rather than reflection as with ink on paper. To date, PolaPrime-UV™ has been a reliable authenticator for genuine identification documents.
Printing of Covert Materials Such as UV
Many images, such as color images, are formed by subtractive techniques, e.g., light is passed through absorbing dyes and the combination of dyes produce an image by sequentially subtracting cyan, magenta, and yellow components to provide the full color image. In the case of a UV fluorescing image, the UV image is formed by light emitting from fluorescing dyes or pigments as they are activated by a UV light or energy source. A UV image can be imparted to an ID document via methods such as thermal transfer or D2T2.
Regardless of whether the UV materials are imparted via D2T2 or mass transfer panel, both panels produce transmissive images—the mass transfer panel produces a bitonal (e.g., two tones) image and the dye sublimation panel produces a monochromatic (or shaded) image.
Optically Variable and Tamper Evident Features
As color photocopiers and other similar imaging systems (e.g., scanners) have increased in quality, availability, and popularity, there has been a corresponding increase in the counterfeiting of security documents such as bank notes, passports and identification cards. Thus, issuers and creators of legitimate security documents have been attempting to add security features to the documents that are difficult to obtain and/or difficult (or impossible) to photocopy or scan. Such security features can also serve to enhance the perceptions and resistance to simulation of existing features on the security documents.
For example, it is known to provide on such security documents optically variable features (which generally cannot which cannot be accurately reproduced by a photocopier or scanner because such features can be invisible to, or viewed differently, by a photocopier. Because some types of photocopying processes reflect high energy light off an original document containing the image to be copied, from a single viewing angle, a security feature may have a different appearance depending on angle at which it is viewed, or a different appearance in reflected and transmitted light.
Color shifting and other optically variable pigments, inks, dyes, and colorants (collectively "optically variable media") have a feature of appearing to change color as the viewing angle of an observer changes (or as the angle of incident light striking the media changes). Optically variable media have been used on security documents, such as identification cards, credit cards, checks, title document, currency, etc. The optically variable property provides several advantages when used on security documents: (a) the presence and appearance of optically variable quality provides another "check" or method to authenticate the security document; (b) optically variable media are generally more difficult for a layman to obtain and use properly, thus helping to prevent (or at least limit) forgery and to make forgeries and/or alteration easier to detect; and (c) photocopiers and scanners generally will not reproduce most types of optically variable media, helping to reduce unauthorized reproduction or counterfeiting of such documents. Optically variable media also can be used with many other different types of articles, such as consumer goods (e.g., toys, cars), paper products (e.g., greeting cards, magazines), and in the fine arts (e.g., works of art).
Several methods exist to create optically variable media and to apply such media to security documents. One method involves dispersing in a medium (e.g., paint or ink) a plurality of relatively small particles (typically flakes) that have specific optical properties. One example of a particle is a particle comprising a plurality of thin film layers, each film having a particular color and/or optical property. Another example of a particle that can have an optically varying appearance is described in a commonly assigned patent application Ser. No. 09/969,200, entitled "Use of Pearlescent and Other Pigments to Create Security Documents", by Bentley Bloomberg and Robert L. Jones, filed Oct. 2, 2001 (hereinafter "the '200 application"), (now U.S. Pat. No. 6,827,277), the contents of which are incorporated by reference herein in their entirety.
U.S. Pat. No. 6,827,277 describes a media having optically variable properties which includes, in one embodiment, particles comprising flat, irregularly shaped mica platelets coated with titanium dioxide and/or iron oxide. These particles, when dispersed in a media, can give a generally "pearlescent" effect, with smaller particles producing a "satin" effect and larger particles producing a "glitter" effect. In many instances, optically variable media are incorporated into a material such as a laminate layer or overlaminate layer, providing an optically variable indicia that overlays other information on the card. Generally, such an optically variable indicia contains "fixed" data (information that is the same from card to card).
Another method of providing optically variable materials is through the use of certain types of liquid crystals. It is known that certain liquid crystal materials exhibit a difference in color when viewed in transmission and reflection as well as an angularly dependent colored reflection. A liquid crystal is a type of molecule that, when heated above its melting point, can enter a state that exhibits characteristics of both isotropic melt and an ordered crystal. In the so-called liquid crystal state, a liquid crystal molecule can be moving like a liquid but still exhibit degrees of molecular order normally only found in solid crystals. As a result, the liquid crystal can have some physical properties which are angle dependent in the liquid crystalline state, including refractive index. This can enable the liquid crystal to have unique optical properties, including a varying appearance as the viewing angle changes, because of interference effects that cause reflection of certain spectral components of incident light and transmission of the remaining spectral components.
Liquid crystal materials have been incorporated into documents, identification cards and other security elements with a view to creating distinctive optical characteristics. U.S. Pat. No. 4,637,896 provides further information about polymeric liquid crystals, and the disclosure of this patent is hereby incorporated by reference.
It will be appreciated that the security of an identification document will be at least partially dependent upon the particular structure and properties of the layers and the ease with which a successful intrusion can be accomplished. In the case, for example, of the dye image-receiving element of the U.S. Pat. No. 4,738,949, there is produced a monolithic ID card, by which is meant that the background information and the photograph or other personalized information are contained in the same layer. It is indicated in the patent (col. 2, lines 63-66) that, in this way, tampering with the photograph will destroy the background information and forgeries can be prevented.
In U.S. Pat. No. 5,261,987, reference is made to the ID cards of the aforesaid U.S. Pat. No. 4,738,949 and to the lamination of a transparent laminate (employing adhesive) onto the image-bearing surface. It is indicated that attempts to delaminate or peel apart the double composite laminate caused the thermally-transferred dye image to be lifted off the polycarbonate dye-receiver layer by virtue of the strong adhesion provided by the adhesive. It is further disclosed that, in the case of the lamination between polyvinyl chloride sheets of a support sheet carrying a polycarbonate surface having personalized and background information thereon, the incorporation of the support sheet into the ID card renders the card susceptible to being delaminated and altered. There is, thus, disclosed in U.S. Pat. No. 5,261,987 a method of increasing tamper resistance whereby personalized information is printed (by thermal dye transfer printing) onto the exposed surface of a polycarbonate receiver sheet and the polycarbonate receiving layer of the receiver element is then adhered and transferred to a cardstock material pre-printed with background information.
Technologies exist that combine both optically variable properties and tamper evident properties. One example is a type of prefabricated coating of a liquid crystalline material that is available as the ADVANTAGE product available from Advantage ID Technologies, Inc., of Lancaster, Pa., which is part of Applied Optical Technologies, plc, of Parkton, Md. and the United Kingdom. The ADVANTAGE product is an optically variable security coating that can be used to protect documents, components, products, etc., from counterfeiting, alteration, and compromise. The ADVANTAGE material is provided in the form of security laminates (heat activated) and security labels. In at least one form, the ADVANTAGE material comprises a polymeric liquid crystal layer and a tamper evident layer.
Using the ADVANTAGE product, anti-counterfeiting substances can be embedded in the card or applied as a laminate, producing an image that changes color (in a trimodal manner, from transparent to orange to green) as a card is tilted. This trimodal color change is difficult to impossible for known copiers, scanners, and desktop publishing systems to copy. The image itself can be designed to be easily seen by an unaided naked eye. If an attempt is made to tamper with a document to which the ADVANTAGE product has been applied (e.g., as a security feature), chemical coatings that are part of the ADVANTAGE product fracture into microfragments, making it difficult to tamper with the security feature without destroying the security document to which it was applied or in which it was embedded. Often, evidence of such tampering can be seen by an unaided naked eye (or a naked eye aided by the use of an ultraviolet light source, if the tamper evident layer is a UV layer). In one example, the chemical coating is made from a material capable of fluorescing under UV light, such that the fractured UV coating is visible only under UV light.
Although it is known to use optically variable media on security documents, use of such media can sometimes have limitations. For example, many optically variable media are substantially opaque, which can limit their application and use on particular types of security documents, as well as the type and/or design of indicia that are printable with such optically variable media. For example, the relative opacity of many optically variable media means that an indicium (printed with most optically variable media) that is intended to overlay other information generally has an "open" type of design (such as a design with widely spaced lines, or significant spaces between lines/dots), to permit information overlaid by the indicia to be substantially perceived.
Further, for some types of security document (e.g., drivers licenses, identification cards), the issuer wishes to provide a lot of information in a relatively small card area. In particular, it often is desirable to print information such as images of the bearer on a card. Such images typically are not "open" enough to be usable with most conventional optically variable media. Thus, applying an optically variable media that is opaque to such a card and printing an image with it means that it can be difficult to put other information in that area that was printed/overlaid using the optically variable and still have the non-optically variable information be perceivable to an unaided human eye (for authentication or other purposes).
It also would be desirable to ensure that the optically variable feature is further protected by additional covert security elements that are very difficult to obtain and to embed within the laminates of an identification document. For example, infrared media, such as inks, pigments, and dyes, are invisible unless viewed using a special light source and also can be very difficult for a counterfeiter to obtain and to properly apply into identification documents, and would be advantageous to use in a security feature application. Specific types of ultraviolet inks, which are "tuned" to fluoresce at only particular ultraviolet light wavelengths, also can be advantageous in a security feature application. They also will be difficult to view without access to and use of the particular light source. Use of such difficult to obtain media also can act as a forensic feature, because the sources for such media are limited and sales and access are often controlled, thus enabling an investigator to better identify the source of a given infrared, ultraviolet, or other covert media.
The ID document counterfeiter remains surprisingly resourceful. Improvements are needed to stay ahead of the counterfeiter. One counterfeiting technique involves a de-lamination attack. Consider an ID document that includes a printed substrate covered by a laminate layer. A de-lamination attack removes the laminate layer, sometimes with the aid of heat, to access information printed on the substrate. Once revealed, the counterfeiter can alter the printed information and reuse the substrate or laminate. It would be further desirable to be able to readily detect whether such tampering and/or a forgery has occurred with respect to an identification document and/or any indicia on it. For example, because variable indicia (e.g., a birthdate) is a frequent target of alteration and/or other types of fraud, it would be desirable if a security feature could be constructed and arranged so as to show if an alteration attempt was made on a given indicia.
Some ID documents are susceptible to this type of attack. Consider the ID document including a substrate, ink applied to the substrate (or laminate layer) to convey information and a laminate layer covering the ink and substrate. Conventional inks generally include a strong adhesion to either a document substrate or to a laminate. A counterfeiter can use this design characteristic (adhesion) to his advantage. Upon de-lamination, the ink may adhere to the substrate layer or to a laminate layer. Regardless, the printed information is typically preserved on at least one layer and may be used again. (For example, if the ink adheres to a laminate, the counterfeiter can reuse the laminate. Or if the ink adheres to the substrate, the counterfeiter can perhaps alter the information by applying additional ink, or simply reuse the remaining information on the substrate.).
U.S. Pat. No. 5,380,695, herein incorporated by reference, discloses an identification document designed to help deter intrusion attempts. This patent describes an image-receiving element that includes a support, a polymeric security layer including printing, and an image-receiving layer. The polymeric security layer is designed such that its cohesivity is less than its adhesivity for each layer that is contiguous thereto. A printed security pattern is hopefully destroyed through partitioning of the security layer during an attempted de-lamination of the image-receiving layer from the image-receiving element.
To provide these and other advantages, the invention described herein proposes a unique security feature that combines an optically variable feature, a forensic feature, and a tamper evident feature. One portion of the security feature is both visible and at least substantially translucent in visible light, enabling it to be applied to virtually any portion of an identification document, including being overlaid over other information on an identification document. At least one other portion of the security feature is visible only in a light that is not visible to the naked eye, such as UV or IR light. In one embodiment, the security feature comprises a first covert layer, an optically variable layer, and a second covert layer. The first covert layer comprises a patch of first material applied over a first side of the optically variable layer, where the first material comprises a first covert material that is visible to the naked eye only under at least one predetermined light wavelength. The presence of the first covert material is generally not known to the public. The optically variable layer comprises a layer of material capable of presenting a varying appearance depending on the angle from which the optically variable material is viewed. The second covert layer is disposed along a second side of the optically variable layer and comprises a second layer of a second covert material that breaks upon intrusion.
Advantageously, the security feature is overlaid at least partially over a variable indicia on the identification document. If an attempt is made to delaminate or otherwise remove the security feature, a portion of the security feature fractures, to provide tamper evidence.
In one embodiment the invention provides a security feature, comprising a first covert layer, an optically variable layer, and a second covert layer. The first covert layer comprises a first covert material that is not visible to a human eye under except under a first condition. The first covert layer further comprises a material constructed and arranged to produce, upon an attempted intrusion into any part of the security feature, a first effect, such damaging breaking, cracking, rupturing, splitting, fracturing, splintering, changing color, changing texture, shattering, and destroying, that is visible at least under the first condition. The optically variable layer has first and second sides, the first side being disposed adjacent the first covert layer. The optically varying layer is constructed and arranged to cover at least a portion of the first covert layer. The optically variable layer comprises an optically variable material, such as a polymeric liquid crystal. The second covert layer is disposed adjacent to the second side of the optically variable layer. The second covert layer comprises a second covert material, such as an infrared, an ultraviolet, and/or a thermachromic material, that is visible to the human eye only at a second condition, such as at least one of predetermined wavelength of light in the infrared range, a predetermined wavelength of light in the ultraviolet range, and a predetermined temperature. The second covert layer is constructed and arranged to cover at least a portion of the optically variable layer.
In one embodiment, the first covert layer is operably coupled to the optically variable layer and is constructed and arranged such that an attempted intrusion into the first covert layer causes damage to at least one of the first covert layer and the optically variable layer. In one embodiment, the first and second covert layers and the optically variable layer are constructed and arranged such that an attempted intrusion into the security feature causes damage to at least a portion of at least one layer of the first covert layer, second covert layer, and optically variable layer,.
In one embodiment, the ADVANTAGE material is used for at least one of the optically variable layer and the first covert layer.
In another aspect, the invention provides an identification document, comprising a core layer, a security feature, and a first laminate layer. The core layer, which can, for example, be TESLIN, has first and second sides. The security feature has first and second sides and has a first side operably coupled to a first side of the core layer. The first laminate layer operably coupled to the second side of the security feature. The security feature comprises a first covert layer, a second covert layer, and an optically variable layer. The first covert layer comprises a first covert material that is not visible to a human eye under except under a first condition, the first covert layer further comprising a material constructed and arranged to produce a first effect that is visible at least under the first condition upon an attempted intrusion into the first covert layer. The optically variable layer comprises an optically variable material and has first and second sides, the first side being disposed adjacent the first covert layer, the optically varying layer being constructed and arranged to cover at least a portion of the first covert layer. The second covert layer is disposed adjacent to the second side of the optically variable layer, the second covert layer being constructed and arranged to cover at least a portion of the optically variable layer. The second covert layer comprises a second covert material that is visible to the human eye only at a second condition.
In another embodiment, the invention provides method of making an identification document. A first laminate layer having first and second sides is provided. A first cover layer having first and second sides is disposed adjacent to the first side of the first laminate layer. The first side of an optically variable layer having first and second sides is arranged adjacent to the second side of the first covert layer. The first side of a second covert layer having first and second sides is placed adjacent to the second side of the optically variable layer. The first side of a core layer having first and second sides is aligned to the second side of the second covert layer. The first laminate layer, first covert layer, optically variable layer, second covert layer, and core layer are fixedly attached together. At least one indicium can be formed on the core layer.
In another embodiment, the invention provides a security feature, comprising a first layer of ADVANTAGE material, the first layer having first and second sides and a layer of infrared material coating at least the first side of the ADVANTAGE material.
In still another aspect, the invention provides an identification document, comprising a layer of ADVANTAGE material, the layer having first and second sides, a core layer having first and second sides, a layer of adhesive material applied to at least the first side of the layer of ADVANTAGE material and coupling at least a portion of the ADVANTAGE material to the first side of the core layer, the adhesive material comprising an infrared material, and a substantially translucent layer of laminate disposed at the second side of the ADVANTAGE layer and along at least a portion of the first side of the core layer, the laminate substantially sealing the layer of ADVANTAGE material to the core layer. In one embodiment of this aspect, the core layer further comprises an indicium formed thereon and wherein the layer of ADVANTAGE material is positioned to overlay at least a portion of the indicium.
The foregoing and other features and advantages of the present invention will be even more readily apparent from the following Detailed Description, which proceeds with reference to the accompanying drawings and the claims.
Of course, the drawings are not necessarily drawn to scale, with emphasis rather being placed upon illustrating the principles of the invention. In the drawings, like reference numbers indicate like elements or steps. Further, throughout this application, certain indicia, information, identification documents, data, etc., may be shown as having a particular format, arrangement, shape, outline, cross sectional shape, etc., (e.g., rectangular, elliptical) but that is provided by way of example and illustration only and is not limiting, nor is any format, arrangement, shape, outline, cross sectional shape, etc, intended to represent any actual resultant format, arrangement, shape, outline, cross sectional shape, etc, that occurs during manufacturing of identification documents.

Optically variable security features having covert forensic features


A comparator has a differential pair circuit and a current control circuit. The differential pair circuit has first and second comparator transistors, and is arranged to compare a first input and a second input according to a clock signal to generate a result indicating whether a difference of the first and second inputs exceeds an internal offset. The current control circuit is coupled in series with the differential pair circuit, and configured to provide unequal abilities of drawing currents for the first and second comparator transistors. An amplifier circuit is also disclosed, having a differential pair circuit, a current control circuit, an amplification circuit and a reset circuit.

1. Field of the Invention
The present invention relates to electronic circuits, and in particular relates to a comparator circuit and an amplifier circuit.
2. Description of the Related Art
A voltage comparator compares a first input voltage to a second input voltage, and produces a digital representation, i.e., a binary 1 or 0, at the output indicating which input voltage is higher, that is, the polarity of the voltage difference between the two inputs. An offset comparator has a built-in offset voltage threshold such that the voltage difference of the first and the second inputs has to exceed this threshold in order to make the output switching the binary state.
However, the bias condition of the input differential pair limits the offset range of the built-in offset voltage. Conventionally, when the voltage difference between the two inputs is greater than a certain voltage value, the offset comparator may reach a saturation condition, wherein the built-in offset has no effect on the outcome of the comparator.


A disk drive system employs uniform size data blocks, with each disk having a sectorized track format and each sector of a track including at least one servo burst. Data blocks exhibit a constant data density across a plurality of disk tracks of differing radii. The system comprises read/write apparatus for accessing both servo signals and data signals in each disk sector. A servo system is responsive to servo signals fed from the read/write apparatus to generate a synchronizing signal. A data sector pulse generation circuit is responsive to the synchronizing signal to generate and pass to the read/write apparatus, a data sector pulse for each block of data commencing in a sector. That data sector pulse enables operation of the read/write apparatus upon the data block. A control circuit enables the delay of generation of a next data sector pulse when any block of data is split by a servo burst. The delay period is the duration of the servo burst and the portion of the data block that follows the servo burst.

Present day disk drives employ a number of servo techniques for controlling transducer positioning. Larger form-factor disk drives employ a dedicated servo surface on one disk platter to enable the generation of signals for servo control of read/write head position. In such larger disk drives, this servo signal generation technique is practical since most of those drives contain multiple platters, yielding many recording surfaces. The dedication of one surface to servo signals subjects the disk drive to a minimal "servo overhead".
Smaller form-factor disk drives (e.g., 3.5 inches or smaller) generally contain only one or two disks. In such a drive, if one surface of a disk is dedicated solely to servo information, the overhead can be as high as 50%--which is unacceptable. To minimize servo overhead in the smaller disk drives, servo information has been embedded into the data tracks and is distributed throughout each track. Since servo and data fields are thereby contiguous, differentiation between them becomes critical to the proper operation of the disk drive.
Before a disk drive can be operated to store data, the disks must be formatted. Such formatting involves the partitioning of each recording surface into a plurality of pie-shaped sectors, each sector including a single servo burst. Since each disk track has a different linear velocity from every other track on the disk, signals written at a constant frequency do not exhibit a constant data density from track to track. For instance, a servo burst written at a constant frequency in a sector of an inner track will occupy less linear distance on the inner track than a constant frequency servo burst written on a more radially distant outer track. Nevertheless, servo bursts are written using constant frequency signals across the tracks. In such a case, radially aligned servo bursts occupy different linear distances in their respective tracks, but radially aligned servo bursts occupy an identical time window in each track (the angular velocity of each track is identical). Thus, a timing signal generated to window a servo burst and various signal segments therein can be made the same for each track, irrespective of the radial distance of the track from a disk's spindle axis.
If constant frequency recording is used for data, as it is for servo bursts, the density of data in outer tracks is much less than for data in inner tracks and the resultant storage efficiency of the disk drive suffers. Many hard-disk disk drives therefore employ a method of recording termed "constant density" recording. More specifically, data is written in each track (or in a zone of tracks) so that the signal density is constant across all tracks in a zone. As a result, the frequency of recording of such data in greater radius tracks is higher than the frequency of recording in the more radially-inner tracks.
The prior art has employed two techniques to implement constant density recording. The first method varies the rotational speed of the disk and senses data at a constant data rate. The second technique maintains the rotational speed of the disk constant while increasing the recording rate as tracks approach the outer edge of a disk. The first method has been used in floppy disk drives, but in hard disk drives, it is difficult to vary the disk rotation speed. Therefore, hard disk drives typically use (as aforestated) different recording rates for different zones of tracks, depending upon the location of the track on the disk.
Prior art disk drives using embedded servo bursts have generally appended only a single data field to the servo burst. By knowing the duration of the servo burst, the position of a data field can be determined and the read/write circuitry properly enabled. A problem with the single data field/servo burst configuration is that the recording density on outer tracks suffers if constant size data blocks are employed.
Accordingly, it is an object of this invention to provide a disk drive employing embedded servo bursts with an ability to commence a data sector at any point within the data portion of a disk track.
It is another object of this invention to provide a disk drive employing embedded servo bursts with an ability to split data fields so that they appear in different disk sectors.
It is yet another object of this invention to provide a disk drive employing embedded servo bursts, with circuitry that generates start of data sector pulses at the commencement of each data sector, irrespective of whether a data sector is complete or split.

Programmable start-of-sector pulse generator for a disk drive using embedded servo bursts and split data fields


A prosthetic nucleus prepared from blends of polyvinylalcohol and polyvinyl pyrollidone or its copolymers for replacement of the nucleus pulposus in intervertebral discs is provided. Also provided are methods of replacing the nucleus pulposus and treating disc degeneration-associated pain in mammals using this prosthetic nucleus.

Over five million Americans suffer from chronic lower back pain, which has become the number one cause of lost work days in the United States. As a result, over 20 billion dollars are spent each year for the treatment of lower back pain, making it one of the most expensive health care issues today.
While the causes of lower back pain remain unclear, it is believed that 75% of cases are associated with degenerative disc disease, where the intervertebral disc of the spine suffers reduced mechanical functionality due to dehydration of the central disc region known as the nucleus pulposus. The reduction in the ability of the disc to transmit loads evenly and efficiently between vertebral bodies leads to damage in the annular region of the disc, known as the annulus fibrosis. Fissures or tears in the annulus can translate into a disc that herniates or ruptures, resulting in impingement of the nerves in the region of the disc. This impingement can lead to lower back or leg pain, depending on which nerves have been affected. Current treatments range from conservative bed rest to highly invasive surgical interventions (e.g., spinal fusion and discectomy) that are aimed at reducing pain but not at restoring disc function.
Spinal fusion is achieved by removal of the entire intervertebral disc, filling the gap or space with a bone graft and providing enough stability to the region through metal fixation plates and screws so that the vertebral bodies will fuse together. Although fusion serves to alleviate pain, the fusion does not restore the physiological biomechanics of the vertebral segment. In fact, the lack of motion within the segment can lead to further degeneration of the more distal intervertebral discs (Leong, J. C. et al. Spine 1983 793–799).
Discectomy is employed when the disc has herniated and is impinging on nerve bundles causing pain. In this surgery, the impinging region on the annulus fibrosis is excised, alleviating pressure on the nerves and eliminating pain. Like spinal fusion, however, this approach fails to restore physiological biomechanics of the vertebral segment. Further, the path of disc degeneration is likely to continue and spinal fusion in the future will likely be required.
An alternative approach to treatment of degenerative disease is to remove the diseased disc and replace it with a synthetic implant. Disc replacement may serve to eliminate pain while restoring physiological motion. Designs include low friction sliding surfaces, like a ball and socket (U.S. Pat. No. 5,258,031), spring and hinge systems (U.S. Pat. No. 4,309,777; U.S. Pat. No. 5,320,644; U.S. Pat. No. 4,759,769), contained fluid chambers (U.S. Pat. No. 4,083,477; German Patent DE-OS 3,741,493), and discs of rubber and other elastomers (Edeland, H. G. J. Biomed. Mater. Res. Appl. Biomater. 1989 23: 189–194; U.S. Pat. No. 4,911,716; U.S. Pat. No. 5,171,281). None of these concepts has proven effective in returning functionality to the spine segment. Spring and hinge systems cannot adapt to the changing center of rotation of the disc and fluid filled and elastic materials cannot survive the compressive and torsional loading of the spine biomechanics.
Limited clinical treatment with disc replacement has been performed. Human patients have been implanted with a hexene-based carbon black-filled polyolefin rubber core vulcanized to two porous-coated titanium plates (U.S. Pat. No. 5,071,437), with fracture of the rubber core experienced in 2 of 6 patients (Enker, P. et al. Spine 1993 18: 1067–1070). Clinical data is also available for the LINK disc replacement which consists of cobalt chromium alloy end plates and a polyethylene core (U.S. Pat. No. 4,759,766). In a 93 patient clinical trial, back pain relief was reported in only 20% of patients and leg pain relief in only 40–50% of patients after an average implantation time of one year (Griffith, S. L. et al. Spine 1994 19: 1842–1849).
Attempts have also been made to replace only the nucleus pulposus. Replacement of the nucleus pulposus is expected to arrest the initial dehydration of the degenerated nucleus and return the disc to a fully hydrated state so that the degenerative process, including the associated pain, is postponed or prevented and the mechanical function is restored to the vertebral segment.
Nucleus replacement was first attempted in the early 1960's with self-curing silicone which was injected into the disc space of cadavers (Nachemson, A. Bull. Hosp. Joint Dis. 1962 23: 130–132). Silicone showed early promise as a material for nucleus pulposus replacement until silicone synovitis and its associated complications led to limitation of the clinical use of the material (Cham, M. et al. Skeletal Radiol. 1998 27: 13–17).
Hydrogels are three-dimensional, water-swollen structures composed of mainly hydrophilic homopolymers or copolymers (Lowman, A. M. and Peppas, N. A., Hydrogels, in Encyclopedia of Controlled Drug Delivery, E. Mathiowitz, Ed., John Wiley and Sons, 1999. pp. 397–418)). These materials are for the most part insoluble due to the presence of chemical or physical crosslinks. The physical crosslinks can be entanglements, crystallites or weak associations such as van der Waals forces or hydrogen bonds. The crosslinks provide the network structure and physical integrity. For this reason, hydrogels have also been suggested as a useful material for nucleus replacement. In addition, they can be prepared with mechanical properties similar to the nucleus itself as well as with similar physiological properties, where it maintains about 70% water content under physiological loading conditions. U.S. Pat. No. 5,047,055 and U.S. Pat. No. 5,192,326 describe a hydrogel for use in nucleus pulposus replacement which is comprised of 100% semi-crystalline polyvinyl alcohol (PVA) PVA is a biocompatible polymer that has the ability to absorb water or physiological fluid and survive mechanical loading as would exist in the nucleus region of the intervertebral disc.
However, PVA is not entirely stable within the physiological environment of the body. PVA has been found to degrade through the melting out of smaller crystallites over time, thereby resulting in a reduction of mechanical properties and leaching of molecules into the physiological environment. Accordingly, these devices are limited by instability of PVA that results in mass loss and degradation of mechanical properties over time of immersion in vitro or implantation in vivo.
U.S. Pat. No. 5,976,186 discloses a prosthetic nucleus prepared from hydrogels of lightly crosslinked biocompatible homopolymers and copolymers of hydrophilic monomers, HYPAN or highly hydrolyzed crystalline PVA which exhibit an equilibrium water content (EWC) of from about 30 to about 90%. It is taught that partially hydrated xerogel rods or tubes of these hydrogels can be implanted into the nuclear cavity of an intervertebral disc wherein they can be brought to their EWC more rapidly due to their greater surface area.
The present invention relates to a modified PVA hydrogel for use in intervertebral disc replacement, and more specifically replacement of the nucleus pulposus, which has been stabilized by addition of a second polymer, preferably polyvinyl pyrollidone (PVP) or copolymers of PVP and poly(methyl methacrylate), poly(acrylamide), poly(acrylic acid), poly(acrylonitrile) or poly(ethylene glycol). Implantation of this new hydrogel is expected to be particularly effective in mammals, in particular humans, with early diagnosis of disc disease before the annulus has suffered significant degeneration.

Associating hydrogels for nucleus pulposus replacement in intervertebral discs


The present invention relates to a system for delivering temperature and flow rate controlled warmed air to outlets for use in various apparatus. The system is typically in residential structures, such as homes, but could easily be adapted for apartment buildings as well as commercial buildings.

Residential construction in the U.S. is continuing at a record pace, with over one million new homes built in the U.S. in 2003. This robust growth in new housing is expected to continue beyond 2004.
With the growth of the home building industry, comes growth in segments of the industry, such as upscale homes. These homes typically have central heating and air conditioning systems, and in many of these homes, a central vacuum system. These homes also include numerous upgrades, such as whirlpools, saunas, steam rooms, professional kitchens, and the like. Additional systems are constantly being sought to increase the homeowner's comfort and enjoyment of their residential unit.


A method includes checking a specified security feature of a value document which is present in a specified security-feature region of the value document. The security feature includes captured pixel data which describe spatially resolved with a specified optical spatial resolution, an optical image at least of the security-feature region of the value document, and there are captured ultrasound data which describe an ultrasonic property of the value document at least in the security-feature region, spatially resolved with a specified ultrasonic spatial resolution. The ultrasonic spatial resolution is lower than the optical spatial resolution. From the pixel data there are established first reduced-resolution pixel data for reduced-resolution pixels of the first reduced-resolution image which describe a reduced-resolution optical image at least of the security-feature region of the value document, whose optical spatial resolution corresponds to the ultrasonic spatial resolution.

The present invention relates to a method for checking a security feature of a value document which is present in a specified security-feature region of the value document, in particular a watermark, and to a corresponding apparatus for checking a security feature of a value document which is present in a specified security-feature region of the value document, in particular a watermark.
Value documents are understood here to be sheet-shaped objects that represent for example a monetary value or an authorization and hence should not be manufacturable arbitrarily by unauthorized persons. They hence have security features that are not easily manufactured, in particular copied, whose presence is an indication of authenticity, i.e. of manufacture by an authorized body. Important examples of such value documents are chip cards, coupons, vouchers, checks and in particular bank notes.
Such value documents normally possess a sheet-shaped substrate which can for example carry print elements or foil elements as further elements of the value document.
Such value documents, more precisely their security features, are checked for their authenticity, inter alia, by means of corresponding apparatuses for example, but the certainty of the check, i.e. the certainty with which authentic and forged value documents or security features of the value documents can be distinguished, is, depending on the security feature, not as great as appears desirable.
An example of this the recognition of watermarks, which are understood within the framework of the present invention to be security features that are formed by a specified variation of the thickness of the value-document substrate at equal density, i.e. equal weight per volume. Although such watermarks are difficult to manufacture, there are forgeries of watermarks that are more or less good.

Method and apparatus for checking a security feature of a value document


The invention relates to a floating leisure platform with a heating device (A) for food and a seating facility (14) for one or several people.

The invention concerns a floating leisure platform.
There are conventional floating leisure platforms in the form of rafts, which are, however, relatively unattractive. The use of hired boats that can be driven on water by physical effort is also known (pedal boats). These devices no longer meet the leisure requirements of today's public.
It is therefore the underlying purpose of the invention to provide a floating leisure platform having a high leisure value, which is attractive and offers a wider variety of use.


Method of saturation management of a digital radiographic exposure image in which there are one or more saturation areas, acquired notably after a mammogram on an acquisition chain in automatic mode using a low-dose preexposure image.

The invention concerns the saturation management of an image of an object of high dynamics, that is, presenting too great a variation between the lowest and highest detectable gray level.
It is particularly applicable in the medical field, especially for mammograms in which the thick tissue displays on the image a high dynamics sometimes greater than that of the X-ray detector.
In the medical field, physicians generally use radiographic images of the internal organs of patients to make their diagnosis. The images are obtained by means of an acquisition chain notably including a detector. Each detector possesses a specific dynamics and can therefore register up to a certain maximum level of X-ray exposure called saturation level. If that saturation level is exceeded in an area, all the information is lost in that area. Thus, on a mammogram, the area close to the skin can be partially erased.
In the course of automatic mammography, two images are made:
a first low-dose preexposure image (saturation is thus avoided) from which certain characteristics of the breast are determined, such as its composition and its radiological thickness. That preexposure image is no longer subsequently used;
a second normal-dose exposure image from which the physician makes his diagnosis.
However, this method of operation does not make it possible to solve possible saturation problems that can occur during the exposure phase. In fact, the object to be X-rayed presents a dynamics which can be more or less appreciable in any given area and the detector of the image chain also possesses its own dynamics. Saturation occurs when the dynamics of the detector is less than that of the object to be X-rayed. Some information close to the skin can be lost.
The invention is aimed at contributing a solution to that problem and, in particular, at making it possible to obtain a digital radiographic image of a body organ whose contour is precisely detected regardless of the dynamics of the organ.
The invention proposes a method of saturation of a digital radiographic exposure image, in which there are one or more saturation areas. The image is obtained following a mammogram on an acquisition chain in automatic mode, using a preexposure image.
According to a general characteristic of the invention, a final image is constructed from the the exposure image and preexposure image.
The invention proposes using the preexposure image obtained in the course of a mammogram in automatic mode in order to recover the information lost by saturation during exposure.
The use of the preexposure image is therefore generally limited to obtaining the characteristics of the organ X-rayed the pre-exposure image is obtained from an X-ray flash at low enough dose not to involve any saturation area. The exposure image, on the other hand, is obtained from X-radiation at normal dose higher than that of the preexposure image and thus entails possible saturation areas.
The invention preferably provides for making a mask from the exposure image by taking the saturation areas into account, and then determining on the preexposure image the areas corresponding to the saturation areas of the exposure image by using the mask. The areas thus obtained are called coverage areas. The area complementing the junction of coverage areas is set at a zero gray level. A digital standardization processing of certain gray levels of both exposure and preexposure images is then carried out and the final image is determined from a combination of the two images thus processed.
According to an embodiment of the invention, the mask is made by detecting all the gray levels higher than a saturation gray level linked to the detector of the acquisition chain.
The mask is, in fact, made by keeping in memory the coordinates of the pixels thus detected. These coordinates make it possible to delimit the saturation areas and, by transferring them on the preexposure images, the pixels of the preexposure image are determined, the coordinates of which are identical to those of the pixels of the saturation areas.
It will be readily apparent to one skilled in the art that this masking operation is correctly carried out only if the two images are perfectly superposable. The two images can, if necessary, undergo a treatment of resetting relative to each other.
In general, according to one embodiment of the invention, the digital standardization processing can be carried out by enhancing the gray level of the coverage areas on the the preexposure image to the same gray level as the unsaturated areas of the the exposure image.
In fact, the pixels of the coverage areas have, on the average, a gray level much lower than that of the exposure image, for the preexposure image is made following a low-dose radiation. The object of the standardization operation is to ensure continuity between the coverage areas of the preexposure image and the unsaturated areas of the exposure image. This operation is of interest only if it is carried out homogeneously, that is, all the pixels of the coverage areas are augmented by the same quantity. This makes it possible to preserve the contrasts and, therefore, always to be able to distinguish the elements of interest.
Finally, the final image is obtained by joining the unsaturated areas of the exposure image with the enhanced coverage areas of the preexposure image.
The final image is therefore composed of the exposure image in which all the saturated areas are replaced by homologous areas of the preexposure image having undergone a digital processing. The information from the saturated areas is thus partly recovered.
According to another embodiment of the invention, the mask is limited to a saturated part of the exposure image corresponding to a peripheral region of the breast X-rayed. The information recovered then makes it possible to delimit the breast precisely.
The limitation of the mask to a small part of the image results in accelerating processing, since the number of pixels processed is less than the number of pixels processed in the case of a mask made on all the saturated areas.
The invention also concerns a system of saturation management of the exposure image. This system comprises:
an acquisition chain capable of elaborating, in addition to the exposure image containing at least one saturation area, a second preexposure image of weaker gray level;
an image processing system containing a means of detection of the pixels of the saturated area of the exposure image in order to form a mask, a means of detection of a coverage area on the second image, the coordinates of whose pixels correspond to the coordinates of the pixels of the saturated area of the exposure image, a means of enhancement of the gray levels of the coverage area to the same gray level as the unsaturated area of the exposure image and a means of addition of the enhanced coverage area of the second image with the unsaturated area of the exposure image in order to obtain the unsaturated final image; and
at least one system of display of the final image.
The digital image processing system therefore performs all the digital operations involving pixels. This system receives the images direct from the acquisition chain, but it can also obtain them from a digital data storage means on a noninstantaneous diagnosis.
The display system can consist of a video monitor and/or a printer connected to the image processing system.
According to an advantageous embodiment of the invention, the acquisition chain operates on automatic mode, for which a first low-dose flash supplies a preexposure image and a normal-dose radiation supplies an exposure image; the preexposure image therefore corresponds to the second image.
The invention is remarkable in that it uses the preexposure image on an automatic operation of the acquisition chain.
In fact, the image is ordinarily used only to determine certain parameters of the body organ X-rayed, but not at all for formation of the digital radiographic image.
Other advantages and characteristics of the invention will appear on examination of the detailed description of a nonlimitative embodiment and of the attached figures, in which:

Method and system of saturation management of radiographic image

Abstract: A mask is made from the exposure image by taking the saturation areas into account;

Abstract: the coverage areas corresponding to the saturation areas of the exposure image are determined on the preexposure image by using the the mask;

Abstract: a digital standardization processing of the gray levels of both the exposure image and the preexposure image is then carried out; and