A separation layer is formed over a substrate having a depressed portion, using a silane coupling agent; a conductive layer and an insulating layer that covers the conductive layer are formed in the depressed portion over the separation layer; and a sticky member is attached to the insulating layer, then the conductive layer and the insulating layer are separated from the substrate. Alternatively, after these steps, a flexible substrate is attached to the conductive layer and the insulating layer.

1. Field of the Invention
The present invention relates to a method for forming a conductive layer and a substrate having the conductive layer. Further, the present invention also relates to a method for manufacturing a semiconductor device having a conductive layer.
2. Description of the Related Art
Conventional methods for forming a conductive layer serving as an antenna, a pixel electrode, a wiring, or the like over a flexible substrate include the following: a method in which a composition that contains particles including a metal element is printed over a flexible substrate by a screen printing method and the composition is then heated and baked to form a conductive layer; and a method in which a conductive layer is formed over a flexible substrate by a plating method.
Patent Document 1: Japanese Published Patent Application No. 2004-310502
In order to form a low-resistance conductive layer by using a composition that contains particles including a metal element, the composition is preferably heated and baked at a high temperature, typically, 200° C. or higher. However, depending on a material, some flexible substrates have a low glass transition temperature, which can be lower than a baking temperature of a composition that contains particles including a metal element. Therefore, there is a problem in that a flexible substrate is deformed in a case of directly printing a composition that contains particles including a metal element over the flexible substrate and performing heating and baking to form a low-resistance conductive layer.
On the other hand, in a plating method, a baking step is not necessary, and a low-resistance conductive layer can be formed at a comparatively low temperature from approximately room temperature to 100° C. However, in a plating method, there are problems in that dangerous chemicals such as sulfuric acid, hydrochloric acid, and cyanogens compounds are used and waste fluids cause pollution.
In a case where a composition is printed over a substrate by a screen printing method, compositions which are applied by filling mesh openings of a screen with the compositions are connected with each other so that they become a linear compound. Therefore, a thickness of a region where compositions have been applied by filling mesh openings of a screen with the compositions is different from that of a region where compositions are connected, and further, a composition having a side surface with a curved (uneven) shape is formed.
Accordingly, in a case where a plurality of conductive layers is formed, there is variation in the thickness and shape of conductive layers, and as a result, there is a problem in that variation in resistance of the conductive layers occurs.
When an antenna, such as a wireless chip capable of transmitting and receiving data wirelessly (also referred to as an ID tag, an IC tag, an IC chip, an RF (radio frequency) tag, a wireless tag, an electronic tag, or an RFID (radio frequency identification device)), is formed using such a conductive layer, inductance varies in a plurality of antennas, and a problem occurs in that variation in resonance frequency and electromotive force accompanying it occurs from one wireless chip to another wireless chip.

Method for forming conductive layer and substrate having the same, and method for manufacturing semiconductor device

Semiconductor Energy Laboratory Co., Ltd.


The present invention is directed towards radiation detectors and methods of detecting incident radiation. In particular the present invention is directed towards photodiodes with controlled current leakage detector structures and a method of manufacturing photodiodes with controlled current leakage detector structures. The photodiodes of the present invention are advantageous in that they have special structures to substantially reduce detection of stray light. Additionally, the present invention gives special emphasis to the design, fabrication, and use of photodiodes with controlled leakage current.

Certain photodiodes have two-electrode radiation-sensitive junctions formed in semiconductor material. Light, which illuminates the junction, creates charge carriers. Reverse current varies with illumination. Photodiodes can be photovoltaic or photoconductive devices, used for detection of optical power and subsequent conversion to electrical power.
Operationally, photodiodes absorb photons or charged particles, facilitating detection of incident optical power and generating current proportional to the incident power, thus converting the incident optical power to electrical power. Light-induced current of the photodiode corresponds to the signal while "dark" current represents noise. "Dark" current is that current that is not induced by light, or that is present in the absence of light. Photodiodes process signals by using the magnitude of the signal-to-noise ratio.
Photodiodes are typically characterized by certain parameters, such as, among others, electrical characteristics, optical characteristics, current characteristics, voltage characteristics, and noise. Electrical characteristics predominantly comprise shunt resistance, series resistance, junction capacitance, rise or fall time and/or frequency response. Optical characteristics comprise responsivity, quantum efficiency, non-uniformity, and/or non-linearity. Photodiode noise may comprise, among others, thermal noise, quantum, photon or shot noise, and/or flicker noise.
Conventionally, in an effort to increase the signal to noise ratio and enhance the contrast of the signal, it is desirable to increase the light-induced current of photodiodes. Thus, photodiode sensitivity is enhanced while the overall quality of the photodiode is improved. Photodiode sensitivity is crucial in low-level light applications and is typically quantified by a parameter referred to as noise equivalent power (NEP), which is defined as the optical power that produces a signal-to-noise ratio of one at the detector output. NEP is usually specified at a given wavelength over a frequency bandwidth.
Essentially active solid-state semiconductor devices, and in particular, silicon photodiodes, are among the most popular photodetectors having a sufficiently high performance over a wide wavelength range with ease of use. Silicon photodiodes are sensitive to light in the wide spectral range, approximately 200 *10−9 m to 1100 *10−9 m, extending from deep ultraviolet through visible to near infrared. Silicon photodiodes, by using their ability to detect the presence or absence of minute light intensities, facilitate the extremely precise measurement of these minute light intensities upon appropriate calibration. For example, appropriately calibrated silicon photodiodes detect and measure light intensities varying over a wide range, from very minute light intensities of below 10−13 watts/cm2 to high intensities above 10−3 watts/cm2.
Conventional photodiodes, as described above, still present numerous problems in their use today. Many of the resources associated with the use of conventional photodiodes, including capital, time, and manpower are wasted in resolving some of the numerous problems including controlling (also referred to as modifying, managing, reducing or eliminating) photodiode leakage current, noise, and stray light. In addition, there are secondary problems that pose problems in conventional photodiode use. These include, but are not limited to, determination and/or selection of apt active area specifications and controlling the higher-wavelength infrared response.
A particularly serious problem associated with conventional photodiodes is leakage current. Leakage current is a major source of signal offset and noise in applications operating in current mode. More specifically, leakage current flows through the photodiode when it is in a "dark" state, or in the absence of light at a given reverse bias voltage applied across the junction. Leakage current is specified at a particular value of reverse applied voltage. For example, reverse bias voltage may be as low as 10 mV or as high as 50 V, whereas the "dark" currents may vary from pA to μA depending upon the junction area and the process used. Leakage current is temperature dependent; thus, an increase in temperature and reverse bias results in an increase in leakage or dark current. A general rule is that the dark current will approximately double for every 10° C. increase in ambient temperature. It should be noted, however, that specific diode types can vary considerably from this relationship. For example, it is possible that leakage or dark current will approximately double for every 6° C. increase in temperature.
Various approaches have been used in the prior art to reduce, eliminate or control leakage current. For example, U.S. Pat. No. 4,904,861, assigned to Agilent Technologies, Inc., discloses "an optical encoder comprising: a plurality of active photodiodes in an array on a semiconductor chip; a code member having alternating areas for alternately illuminating and not illuminating the active photodiodes in response to movement of the code member; means connected to the active photodiodes for measuring current from the active photodiodes; and sufficient inactive photodiode area on the semiconductor chip at each end of the array of active photodiodes to make the leakage current to each end active photodiode of the array substantially equal to the leakage current to an active photodiode remote from an end of the array". Similarly, U.S. Pat. No. 4,998,013, also assigned to Agilent Technologies, Inc. discloses "means for shielding a photodiode from leakage current comprising: at least one active photodiode on a semiconductor chip; means for measuring current from the active photodiode; a shielding area having a photodiode junction substantially surrounding the active photodiode; and means for biasing the shielding area photodiode junction with either zero bias or reverse bias."
U.S. Pat. No. 6,670,258, assigned to Digirad Corporation, discloses "a method of fabricating a low-leakage current photodiode array comprising: defining frontside structures for a photodiode on a front side of a substrate; forming a heavily-doped gettering layer on a back surface of the substrate; carrying out a gettering process on the substrate to transport undesired components from the substrate to said gettering layer, and to form another layer in addition to said gettering layer, which is a heavily-doped, conductive, crystalline layer within the substrate; after said gettering process, removing the entire gettering layer; and after said removing, thinning the heavily-doped, conductive, crystalline layer within the substrate to create a native optically transparent, conductive bias electrode layer".
Similarly, U.S. Pat. No. 6,734,416, also assigned to Digirad Corporation, discloses "a low-leakage current photodiode array comprising: a substrate having a front side and a back side; a plurality of gate regions formed near the front side of the substrate; a backside layer formed within the substrate, near the back side of the substrate, the backside layer having a thickness of approximately 0.25 to 1.0 micrometers and having a sheet resistivity of approximately 50 to 1000 Ohm per square."
U.S. Pat. No. 6,569,700, assigned to United Microelectronics Corporation in Taiwan, discloses "1. A method of reducing leakage current of a photodiode on a semiconductor wafer, the surface of the semiconductor wafer comprising a p-type substrate, a photosensing area for forming a photosensor of the photodiode, and a shallow trench positioned in the substrate surrounding the photosensing area, the method comprising: forming a doped polysilicon layer containing p-type dopants in the shallow trench; using a thermal process to cause the p-type dopants in the doped polysilicon layer to diffuse into portions of the p-type substrate that surround a bottom of the shallow trench and walls of the shallow trench; removing the doped polysilicon layer; filling an insulator into the shallow trench to form a shallow trench isolation (STI) structure; performing a first ion implantation process to form a first n-type doped region in the photosensing area; and performing a second ion implantation process to form a second n-type doped region in the photosensing area."
Also, U.S. Pat. No. 6,504,158, assigned to General Electric Company, discloses "a method of reducing leakage current in an imaging apparatus, including: providing a substrate with at least one radiation-sensitive imaging region therein; forming a guard region in the substrate at or immediately adjacent a cut edge of the substrate to reduce leakage current reaching the at least one radiation-sensitive imaging region from the cut edge when the imaging apparatus is in use; and electrically reverse biasing the at least one radiation-sensitive imaging region and the guard region relative to the substrate."
In addition to leakage current, noise is often a limiting factor for the performance of any device or system. In almost every area of measurement, the limit to the detectability of signals is set by noise, or unwanted signals that obscure the desired signal. As described above, the NEP is used to quantify detector noise. Noise issues generally have an important effect on device or system cost. For example, the reduction of quantum or shot noise influence in interferometers for gravitational wave detection greatly lessens required interferometer arm length. Conventional photodiodes are particularly sensitive to noise issues. Like other types of light sensors, the lower limits of light detection for photodiodes are determined by the noise characteristics of the device.
As described above, the typical noise components in photodiodes include thermal noise; quantum or shot noise; and flicker noise in that order. These noise components collectively contribute to the total noise in the photodiode. Thermal noise, or Johnson noise, is inversely related to the value of the shunt resistance of photodiode and tends to be the dominant noise component when the diode is operated under zero applied reverse bias conditions. Shot noise is dependent upon the leakage or dark current of photodiode and is generated by random fluctuations of current flowing through the device, which may be either dark current or photocurrent. Shot noise tends to dominate when the photodiode is used in photoconductive mode where an external reverse bias is applied across the device. As an example, detector noise generated by a planar diffused photodiode operating in the reverse bias mode is a combination of both shot noise and thermal noise. Flicker noise, unlike thermal or shot noise, bears an inverse relationship to spectral density. Flicker noise may dominate when the bandwidth of interest contains frequencies less than 1 kHz.
In addition to leakage current and noise issues, photodiodes are susceptible to absorption of unwanted or stray light. Stray light is typically that light which propagates through a path other than that which is intended (thus reaching the detector) and excludes the wavelength of interest or an erroneous wavelength. Stray light activates a signal at the detector element. Some of the recognized sources of stray light include ambient light, scattering light from imperfect optical components and/or reflections of non-optical components. The ambient or stray light is assumed to be stationary or slowly fluctuating. Stationary ambient light engenders shot noise, owing to the statistical nature of the production of photocarriers upon impinging on the photodetector. In certain circumstances, the photodiode is exposed to ambient or stray light thus resulting in a high level of noise. Additionally, stray light influences the signal-to-noise ratio (S/N or SNR) and introduces non-linearity.
While photodiodes have a wide viewing angle, many applications require the detection of desired light and concurrent rejection of stray light. Stray light absorption significantly contributes to the total photocurrent delivered by a small active area photodiode and renders it not usable. For example, photodiodes typically used in medical applications need to deliver a precise ratio of photocurrents illuminated from 660 nm and 880 nm. It is possible that an incorrect ratio of photocurrents will be delivered due to the absorption or collection of stray light by the photodiode.
Some attempts have been made in the prior art to correct for the effects of stray light. For example, U.S. Pat. No. 5,869,834, assigned to Sitek Electro Optics, discloses "a position-sensitive photodetector for measuring the position of an incident light beam having energy, comprising: a semiconductor wafer having a doped active surface and a pair of ends; a resistive layer on the active surface of the wafer; two opposed electrodes on each end of said active surface; a stray-light area arranged externally around the active surface, said stray-light area for measuring stray-light contacting said photodetector and for preventing said stray light from affecting a position measuring signal of said incident light beam, said stray light area comprising a doped area containing a p-n junction and a grounding electrode attached thereto, the signal from said stray light area being grounded; a first inactive area externally surrounding said stray-light area and a second inactive area disposed between said active area and said stray-light area, each inactive area connected to said same ground as said stray-light area."
Also, U.S. Pat. No. 6,546,171, assigned to NEC Corporation, discloses "a structure for shielding a stray light in an optical waveguide module, comprising: an optical waveguide substrate supported in an optical waveguide module package; a laser diode (LD) which is mounted on said optical waveguide substrate and emits a first signal light; an optical waveguide which is formed on said optical waveguide substrate and propagates a part of said first signal light; a wavelength divisional multiplexing (WDM, hereinafter) filter which is formed on said optical waveguide substrate; an optical fiber which is situated on said optical waveguide substrate and transmits said part of said first signal light to an optical transmission line; a photodiode (PD, hereinafter) for receiving a second signal light which is propagated through said optical transmission line and transmitted through said WDM filter via said optical waveguide; and a metallic layer which is evaporated on a surface of said WDM filter and provided with a pin hole for transmitting said second signal light to said PD via said WDM filter, wherein a remaining part of said first signal light (a stray light, hereinafter) which is not optically coupled with said optical waveguide is reflected by said metallic layer so that said stray light is prevented from being coupled with said PD."
As discussed earlier, secondary issues also contribute to dark noise and other noise sources that impact photodiode sensitivity. These include primarily determination and/or selection of apt active area specifications (geometry and dimensions), response speed, quantum efficiency at the wavelength of interest, response linearity, and spatial uniformity of response, among others.
While methods and systems of the prior art described above may improve performance, they do not effectively control leakage current, which is equally important to high-performance as well as low-standby and low-power operation devices. Thus, there is still a need for photodiodes with controlled leakage current. Additionally, there is need for low-voltage, low-power designs vis-à-vis photodiodes with aggressive techniques for controlling leakage current. In addition, in spite of the attempts in the prior art, as described above, to reduce or eliminate the effects of stray light absorption with respect to photodiodes, no attempt has been made to design and fabricate photodiodes with special structures to completely avoid stray light.
Thus, there is a need for the design and implementation of methods and apparatuses which completely avoid stray light absorption, reduce or eliminate noise, and control leakage current while lessening the effects of these noise contributing factors. More specifically, what is needed is a photodiode design and fabrication method intended for applications wherein a small active area is employed and wherein a complete avoidance of stray light is of greater importance.

Photodiode with controlled current leakage


A schematic diagram (32) for a printed circuit board (34) is synthesized (20) from a physical design file (56) and a graphical symbol file (86). The printed circuit board (34) has a plurality of parts (36) at least one of which has a plurality of pins (38), those parts (36) and pins (38) being defined in the physical design file (56), from which physical attributes (60) are extracted (58). The finished schematic diagram (32) will include a plurality of symbols (40) at least one of which has a plurality of nodes (41), those symbols (40) and nodes (41) being contained in the graphical symbol file (86) from which graphical attributes (90) are extracted (88). These physical attributes (60) and graphical attributes (90) are integrated (26) along with operator determined position data (168) to produce schematic application page files (30). These schematic application page files (30) may then be processed by a schematic drawing program (156) to plot (158) the finished schematic diagram (32) on a visual medium.

There often occurs a need to create or re-create a schematic diagram of a circuit already realized in printed-circuit form. Such a need may occur because the original schematic has been lost or damaged, or, perhaps more commonly, because modifications and revisions to the circuit have been made over time but not reflected in the original schematic.
Regardless of the reason for the need, current practice requires that a schematic be created manually by correlating all parts and connections on the printed circuit board. This process is time-intensive, tedious, and prone to error.
A marked disadvantage of creating schematics manually is the inherent inflexibility in this process. Once created, such a mechanical schematic does not lend itself readily to modification nor to reorganization.


A method of manufacturing an electronic circuit assembly that includes a number of electrically interconnected flexible films, each flexible film having a flexible electrical wiring circuit. The electrical wiring circuits are interconnected between film layers and the film layers are adhered to a molded backing structure. A first flexible film is formed with a pattern of flexible electrical wiring circuits created on at least one surface thereof. The first flexible film has a passage that provides an electrical connection through the flexible film. A second flexible film is formed with a pattern of flexible electrical wiring circuits created on a least one surface thereof. The second flexible film has an electrical interconnect feature that connects with the electrical passage on the first film and electrically connects the first film with the second film. The first flexible film is overlaid juxtaposed the second flexible film so that the passage is aligned adjacent the electrical interconnect feature. The first and second flexible films are placed within an open mold. The mold is closed and a plastic material is injected within the mold adjacent at least one surface of the first and second flexible films. The molten plastic adheres to the first and second flexible films and forms an integral backing structure. The backing structure and first and second flexible films together form the circuit assembly.

1. Field of the Invention
The present invention relates to a method of manufacturing an electronic circuit assembly from two or more flexible films. More specifically, the present invention relates to a method of simultaneously connecting two or more flexible films and integrally molding a rigid backing on the flexible films by injection molding and the article produced by this method.
2. Description of the Related Arts
It is known to manufacturing circuit assemblies from flexible films having flexible electronic circuits printed or traced thereon. An example of commercially available films produced by this construction is illustrated in U.S. Pat. No. 5,461,202. Flexible films enable the production of electronic circuit boards into highly contoured, three-dimensional shapes. They also allow the electrical circuits to be manufactured separately from the backing structure. This enables the use of different materials for the backing structure and film. One way that flexible films are used is through a process called film capture or in-molding. In-molding refers to the process where a flexible film of either metal, polymer or a combination of both is inserted into a mold and subsequently molded into a circuit assembly. The film becomes adhered to the backing structure by either mechanical interlocking, adhesives or an interdiffusion of the resin and polymer film. These films typically contain electrical wiring features or circuits to create a functional electronic module when fully assembled with electronic components.
One example of an electronic circuit made from an in-molding process is illustrated in U.S. Pat. No. 5,118,458 ('458). This reference teaches a method of producing a multi-layer circuit assembly by sequentially building up layers of flexible films. A first flexible film has a circuit traced thereon and a hot-melt adhesive is placed on the reverse side. The film is then placed within a molding tool and a resin is injected against the facing side of the film. The mold is heated to cure the circuit traces. Additional film layers are sequentially added. Through-holes are formed through the layers of film and the through-holes filled with a conductive paste. Electronic circuits are then attached to the layers of flexible film. The '458 reference requires a number of steps and complicated tooling to form the multi-layer circuit assembly. Each layer is separately built-up. Additionally, the layers are only interconnected at one point when the through-holes are made in the built-up film. This reduces the flexibility of interconnecting the separate film layers at multiple locations and the possibility of connecting only two film layers of a multi-layer stack.
It is also known to manufacture electronic circuit assemblies by forming a backing only along a portion of a flexible film as shown in U.S. Pat. No. 5,220,488 ('488). The '488 patent teaches placing an elongated film into a mold tool where only a portion of film receives an injection molding backing. The '488 device does not teach the use of multi-layer films to create a complex circuit design. While the films and backing produced by the '488 device can be folded into compact shapes, three-dimensional backings are not taught.

Method of manufacturing a circuit assembly from two or more layers of flexible film


There are disclosed an image processing method and apparatus for generating a panoramic image in which the hue or brightness discontinuities generated at the seams of source images are reduced. According to the image processing method of this invention, upon compositing source images (221, 222) having an overlap portion, the hue or brightness of each source image is converted (H211, H221) using a reference image which has overlap portions with both the source images to be composited, and the converted images (241, 242) are composited, thereby reducing the hue or brightness discontinuities generated at the seam of images.

An attempt has been made to sense a real space by an image sensing apparatus mounted on a mobile, and to express the sensed real space as a virtual space using a computer on the basis of the sensed photo-realistic image data (see, e.g., Endo, Katayama, Tamura, Hirose, Watanabe, & Tanikawa: "Method of Generating Image-Based Cybercities By Using Vehicle-Mounted Cameras" (IEICE Society, PA-3-4, pp. 276-277, 1997), or Hirose, Watanabe, Tanikawa, Endo, Katayama, & Tamura: "Building Image-Based Cybercities By Using Vehicle-Mounted Cameras (2)-Generation of Wide-Range Virtual Environment by Using Photo-realistic Images—" (Proc. of the Virtual Reality Society of Japan, Vol.2, pp. 67-70, 1997), and the like).
As a method of expressing a sensed real space as a virtual space on the basis of photo-realistic image data sensed by an image sensing apparatus mounted on a mobile, a method of reconstructing a geometric model of the real space on the basis of the photo-realistic image data, and expressing the virtual space using a conventional CG technique is known. However, this method has limits in terms of the accuracy, exactitude, and reality of the model. On the other hand, an Image-Based Rendering (IBR) technique that expresses a virtual space using a photo-realistic image without any reconstruction using a model has attracted attention. The IBR technique generates an image viewed from an arbitrary viewpoint on the basis of a plurality of photo-realistic images. Since the IBR technique is based on photo-realistic images, it can express a realistic virtual space.
In order to build a virtual space that allows walkthrough using such IBR technique, an image must be generated and presented in correspondence with the position in the virtual space of the user (who experiences walkthrough). For this reason, in such system, respective frames of photo-realistic image data and positions in the virtual space are saved in correspondence with each other, and a corresponding frame is acquired and reproduced on the basis of the user's position and visual axis direction in the virtual space.
As a method of acquiring position data in a real space, a positioning system using an artificial satellite such as GPS (Global Positioning System) used in a car navigation system or the like is generally used. As a method of determining correspondence between position data obtained from the GPS or the like and photo-realistic image data, a method of determining the correspondence using a time code has been proposed (Japanese Patent Laid-Open No. 11-168754). With this method, the correspondence between respective frame data of photo-realistic image data and position data is determined by determining the correspondence between time data contained in position data, and time codes appended to the respective frame data of photo-realistic image data.
The walkthrough process in such virtual space allows the user to view a desired direction at each position. For this purpose, images at respective positions may be saved as a panoramic photo-realistic image that can cover a broader range than the field angle upon reproduction, and a partial image to be reproduced may be extracted from the panoramic photo-realistic image on the basis of the user's position and visual axis direction in the virtual space, and the extracted partial image may be displayed.
Conventionally, in order to obtain a panoramic photo-realistic image, for example, a plurality of cameras are used. In general, a plurality of cameras are arranged in a radial pattern so that their visual fields can cover a desired visual field (e.g., a full-view (360°) visual field or the like). Images obtained by the respective cameras are temporarily stored in a storage device using, e.g., an optical or magnetic storage medium.
Then, by joining images sensed by the respective cameras at a given position, a panoramic photo-realistic image at that position can be obtained. In this case, in order to reduce hue or brightness discontinuities generated at the seams of neighboring images sensed by the respective cameras, overlapping portions of images sensed by neighboring cameras are continuously blended.
As a data format of a panoramic photo-realistic image, broad visual field (including a full view) images at an identical time from one viewpoint are preferably used. In order to sense such images, an apparatus, which senses images reflected by respective surfaces of a pyramid mirror by a single camera, is used. FIG. 3 shows an example of such apparatus.
As shown in FIG. 3, a pyramid mirror 12 is made up of plane mirrors as many as a plurality of cameras which form a camera unit 11. Each of the cameras which form the camera unit 11 senses a surrounding visual scene reflected by the corresponding plane mirror. If the cameras are laid out so that the virtual images of the lens centers of the respective cameras formed by the plane mirrors match, images can be sensed at an identical time from one viewpoint. Hence, by compositing the images sensed by the respective cameras, a full-view panoramic image at an identical time from a single viewpoint can be generated.
However, since the image sensing apparatus shown in FIG. 3 forms nearly no overlapping portions between images sensed by the cameras corresponding to neighboring plane mirrors, the conventional method that reduces hue or brightness discontinuities using the overlapping portions upon compositing images cannot be applied, and the seams of the images stand out.

Image processing method and apparatus for generating panoramic image


A validation phase is performed at an RFID reader, in order to ascertain which of a plurality of potential candidates for authentication, are actual candidates for authentication. Once a candidate has been successfully validated, an authentication phase is initiated with a host computer, to determine whether the information presented by the candidate matches expected information about the candidate. If the authentication is considered successful, a final authorization procedure may be performed, or the authenticated candidate may be granted certain predetermined permissions. By performing the validation phase locally at the reader, the need for accessing a host computer is reduced and unnecessary queries to the host computer are avoided.

Both passive and active RFID technologies are being used increasingly to control access, such as building access, vehicle access, etc. Typically, in an RFID-enabled system, access to a building or vehicle requires an RFID tag (hereinafter referred to simply as a tag) to be placed in proximity of an RFID tag reader (hereinafter referred to simply as a reader). The positioning of the tag vis-à-vis the reader can be done either deliberately, by flashing a tag-containing card in front of a suitable reader, or as a matter of course if the tag is embedded in a badge or under the skin. Access to the building or vehicle is then allowed only if the data stored in and received from the tag (e.g., a user ID) corresponds to an entry in a database of authorized user IDs, typically stored in a server remote from the reader.
As RFID technology gains widespread usage in an increasing number of industries, at least two problems are expected to arise in the above-described access control context. The first such problem is related to security, and is especially evident if one imagines the situation where a malicious entity gains access to the database of authorized user IDs. With this information, the malicious entity can engage in the production of tags that emulate those of the persons associated with the authorized user IDs in the database. Recognizing this deficiency, the industry has attempted to address the security problem, at least in part, through the use of encryption techniques. Specifically, instead of storing a user ID, a given tag is designed to store the user ID as encrypted by a secret encryption key. A reader reading the tag proceeds to decrypt the user ID using a known decryption key, and then compares the (decrypted) user ID to the database of authorized user IDs in the usual fashion. In this scenario, a malicious entity that gains access to the database of authorized user IDs, but without the secret encryption key, will not be able to reproduce the encrypted user ID required to permit access to the building or vehicle.
The second problem that is expected to arise is one related to volume. As RFID tag readers become more sensitive and as the number of objects possessing RFID tags increases, there may be, at any given moment, a wide array of tag-containing objects in the vicinity of a given reader. Yet the vast majority of these tag-containing objects are not intended to be submitted to the reader for access control purposes. For example, a reader positioned at the entranceway to a building may, in the future, be exposed to signals emitted by one or several (or none!) building access cards, while also being in the vicinity of hundreds of other tag-containing items (briefcases, laptops, vehicles, automobile tires, wallets, credit cards, etc.) that are completely unrelated to building access. Unfortunately, however, the reader has no way of knowing which tags are being intentionally presented to it for access control purposes, and therefore must make the assumption that each tag needs to be authenticated.
The risk of picking up signals emitted by multiple tags can only increase as the RFID industry advances on the standardization front. On the one hand, there are indications of industry preparedness, such as the development of protocols in order to manage collisions at a reader performing data acquisition (e.g., by using random back-off techniques reminiscent of LAN access protocols). However, an issue that is overlooked by these and other prior art proposals is the difficulty caused by the delay resulting from having to perform numerous queries to a database of user IDs, where such database is typically located remotely from the reader. As a result, the bandwidth between the reader and the database, as well as the computational speed of the database, become significant bottlenecks in the quest for real-time performance in an access control scenario. These bottlenecks become even more obstructive if the above-described encryption techniques are employed, as the net effect is the introduction of further delay in the process.
Against this background, it is clear that there is a need for improved access control techniques in RFID-based systems.

User authentication for contact-less systems


A phototherapy device has a phototherapy handpiece, an optical fiber attached to the phototherapy handpiece, and a laser phototherapy light source. The phototherapy handpiece, has a handpiece body that defines an interior region and has an outer surface which defines a foot of the phototherapy handpiece, an optical fiber drive assembly disposed at least partially within the interior region of the handpiece body has an optical fiber attachment portion that is movable relative to the handpiece body. The optical fiber drive assembly includes a driving component which causes the attachment portion to move relative to the handpiece body, and a damping component which resists the motion of the optical fiber attachment portion such that the optical fiber attachment portion attains a substantially constant speed motion relative to the handpiece body.

1. Field of the Invention
The present invention pertains to a phototherapy device and method, and more particularly to a handpiece and method for advancing an optical fiber.
2. Description of the Related Art
Devices and methods for performing various types of laser surgery using optical fibers have become widespread. One relatively new application is myocardial revascularization which is used as an alternative to coronary artery bypass surgery. Trans-myocardial revascularization is a method for treating ischemic heart disease in which the heart muscle or myocardium does not receive an adequate blood supply. Trans-myocardial revascularization helps supplement the blood supply delivered to the heart by providing the heart muscle with direct access to blood within the ventricle chamber.
Lasers have been proposed in trans-myocardial laser revascularization to produce channels in the ventricle wall. The channels provide blood flow to the ischemic heart muscle. Optical fibers are useful for directing laser energy to the desired regions of the heart muscle. However, in order for lasers to be effective in trans-myocardial revascularization, the energy from the laser must be concentrated on a narrow region of the heart tissue. As tissue is ablated, if the optical fiber is held in a fixed position, the surface being cut moves away from the area of greatest laser energy concentration. Consequently, optical fibers are advanced in the cutting direction as the tissue is ablated in order to concentrate energy on the heart tissue. In other words, one may think of the optical fiber as ablating a channel through the heart tissue. If the laser energy is not concentrated on a sufficiently narrow region of the heart tissue, the laser begins to heat up regions of the heart tissue without ablating narrow regions of tissue. This can lead to blood coagulation and damage to the heart tissue.
Devices are known in the art for advancing optical fibers using electric motors. However, such devices are complicated and expensive.
Mechanical devices are also known in which optical fibers are advanced manually by the operator through a rack-and-pinion type of mechanism. However, such devices have the disadvantage that it is difficult to control the speed of the forward advancement since the speed depends on the operator moving a lever or some similar mechanical device.


A semiconductor memory device with a power source voltage step-down circuit which generates a stepped-down voltage from electric power supplied from outside and supplies this stepped-down voltage to a memory cell array and peripheral circuits. Current switching device interposed in a circuit or circuits of the semiconductor memory device other than the memory cell array and a switch controlling signal generating means for generating a controlling signal in response to a signal from the outside are provided. The current switching device performs switching of current to flow through the circuit in response to a controlling signal.

1. Field of the Invention
This invention relates to a semiconductor memory device, and more particularly to a semiconductor memory device wherein the internal memory cell array and the peripheral circuit operate at a voltage lower than a power source voltage supplied from the outside and wherein a power source step-down circuit is provided for generating a voltage to be supplied to the memory cell array and the peripheral circuit.
2. Description of the Prior Art
In conventional SRAMs (static random access memories) of the CMOS (complementary metal oxide semiconductor) configuration, most of power source current upon waiting for circuit operation is consumed by an internal memory cell array. Current consumed by peripheral circuits other than the memory cell array such as an address decoder circuit and an operation controlling circuit is so low due to the low current consumption characteristic of the CMOS transistor itself that it can be ignored. For example, in an SRAM having a storage capacity of 1 Mbits, the current consumed by the entire memory cells for 1 Mbits is about 1 .mu.A, while the current consumed by the entire peripheral circuits upon waiting is about 0.05 .mu.A.
In recent years, as the fine working technique for VLSI (very large scale integration) advances, MOS transistors having a gate length of less than 0.5 .mu.m or so are employed for SRAMs having a storage capacity of 4 Mbits or so. However, when a MOS transistor having a gate length of less than 0.5 .mu.m or so is operated at the power source voltage of 5 V which is conventionally used, it is difficult to assure the reliability thereof against hot carriers. Therefore, an SRAM of the type mentioned is so constructed that a voltage step-down circuit is provided on a common semiconductor IC (integrated circuit) chip. The step-down circuit steps down the power source voltage of 5 V from the outside to an internal circuit voltage of, for example, 3.3 V, which is supplied to the internal circuits of the semiconductor memory device, that is, to the memory cell array and peripheral circuits.
FIG. 1 shows construction of a semiconductor memory device including a power source voltage step-down circuit. Referring to FIG. 1, peripheral circuit 7 and memory cell array 8 are interconnected by internal buses 9, and chip select terminal CS and address input terminals A.sub.0 to A.sub.n are connected to peripheral circuit 7. Internal circuit voltage V.sub.int is supplied from voltage step-down circuit 6a to peripheral circuit 7 and memory cell array 8.
Voltage step-down circuit 6a has power source voltage input terminal TC to which external power source voltage VCC is supplied, and includes constant-current source 1a, series diode circuit D1 including two diodes connected in series, a pair of operating amplifiers 3A and 3B, a pair of resistors R1 and R2 connected in series, and P-channel MOS transistor QP1 for providing a series controlling output. It is to be noted that, in the accompanying drawings, each P-channel MOS transistor is shown circumscribed by a circle, while each N-channel MOS transistor is shown without being circumscribed by a circle.
Constant-current source 1a is supplied with external power source voltage VCC by way of voltage input terminal TC and generates constant current I1a. Series diode circuit D1 is connected on the anode side thereof to constant-current source 1a by way of first node N1 and is grounded on the cathode side thereof. Consequently, series diode circuit D1 is supplied with constant current I1a and generates forward voltage 2 V.sub.f. Here V.sub.f is a forward voltage drop per one diode. Forward voltage 2 V.sub.f is supplied to the "+" terminal (positive input terminal) of first operational amplifier 3A. The output signal of first operational amplifier 3A, that is, reference voltage V.sub.ref, is divided by resistors R1 and R2 and is fed back to the "-" terminal (negative input terminal) of first operational amplifier 3A. Reference voltage V.sub.ref is also supplied to the "+" terminal of second operational amplifier 3B. The output of second operational amplifier 3B is connected to the gate of MOS transistor QP1, while the "-" input terminal of second operational amplifier 3B is connected to the drain of MOS transistor QP1. The source of MOS transistor QP1 is connected to power source input terminal TC so that the drain voltage of MOS transistor QP1 is supplied as internal circuit voltage V.sub.int to peripheral circuit 7 and memory cell array 8.
Internal circuit voltage V.sub.int, reference voltage V.sub.ref, forward voltage V.sub.f of each diode, and the resistances of resistors R1 and R2 have the relationship of V.sub.int =V.sub.ref =2 V.sub.f {(R1+R2)/R2}. Here, if it is assumed that, for example, V.sub.f =0.5 V, R1=2.3 k.OMEGA. and R2=1 k.OMEGA., then internal circuit voltage V.sub.int is equal to reference voltage V.sub.ref and is 3.3 V. While peripheral circuit 7 and memory cell array 8 are constituted from MOS transistors having a gate length of 0.5 .mu.m or so, since internal circuit voltage V.sub.int is, for example, 3.3 V and is sufficiently low, reliability against hot carriers can be assured.
Since a sufficiently high current driving capacity is required for P-channel MOS transistor QP1 to supply internal circuit voltage V.sub.int, P-channel MOS transistor QP1 is designed into a MOS transistor of the dimensions, for example, of a gate length of 1.0 .mu.m and a gate width of 1,000 .mu.m. Meanwhile, since external power source voltage VCC is applied as is to voltage step-down circuit 6a, the gate length of the MOS transistors employed in voltage step-down circuit 6a is designed greater than 0.8 .mu.m or so.
In power source voltage step-down circuit 6a, constant dc current I1a always flows through series diode circuit D1 in order to keep the potential at first node N1 equal to 2 V.sub.f. Further, in order to keep reference voltage V.sub.ref also at second node N2 at which first and second operational amplifiers 3A and 3B are connected to each other, dc current I2 always flows through resistors R1 and R2.
Here, the construction of constant-current source 1a is described with reference to FIG. 2. Constant-current source 1a is constituted from P-channel MOS transistor QP3, series diode circuit D2 including a pair of diodes connected in series, and resistor R3. The source of MOS transistor QP3 is connected to power source input terminal TC, while the drain of MOS transistor QP3 is connected to first node N1. The anode of series diode circuit D2 is connected to power source input terminal TC, and the cathode of series diode circuit D2 is connected to the gate of MOS transistor QP3. Resistor R3 is interposed between the gate of MOS transistor QP3 and the ground. The gate-source voltage of MOS transistor QP3 is made equal to forward voltage 2 V.sub.f of series diode circuit D2 so that the drain current of MOS transistor QP3 is kept to a fixed value and serves as a constant-current source. Also here, dc current I3 flows constantly through dc diode circuit D2 and resistor R3 in order to generate forward voltage 2 V.sub.f.
Exemplary construction of first operational amplifier 3A is shown in FIG. 3. Referring to FIG. 3, operational amplifier 3A is constituted as a known CMOS current mirror type amplifier circuit including a pair of P-channel MOS transistors QP13 and QP14 and three N-channel MOS transistors QN18 to QN20. MOS transistors QP13 and QP14 are connected at the sources thereof to power source input terminal TC and at the gates thereof commonly to the drain of P-channel MOS transistor QP13. The drains of N-channel MOS transistors QN18 and QN19 are connected to the drains of P-channel MOS transistors QP13 and QP14, respectively, and the sources of MOS transistors QN18 and QN19 are connected commonly and are grounded by way of a channel of MOS transistor QN20. Terminals a and b are connected to the gates of MOS transistors QN18 and QN19, respectively. Terminals a and b are the "+" input terminal and the "-" input terminal, respectively, of operational amplifier 3A. External power source voltage VCC is supplied to the gate of MOS transistor QN20. The drain of the other P-channel MOS transistor QP14 is connected to output terminal C.
In operational amplifier 3A, when the potentials at input terminals a and b are higher than ground potential GND by a voltage higher than the threshold voltage of the MOS transistors, steady current I4 exists which passes through MOS transistor QN20. Also, the other operational amplifier 3B has a similar construction to operational amplifier 3A and involves a steady current.
In power source voltage step-down circuit 6a of the conventional semiconductor memory device, steady currents I1a, I2, I3 and I4 always flow, and the total of the steady currents is 100 .mu.A or more, which is higher by two figures than the ordinary current consumption of the memory cell array.
Meanwhile, when a semiconductor memory device is constructing using a BiCMOS integrated circuit in which bipolar transistors and CMOS transistors are formed in a mixed condition, a data bus connected to a data sensing circuit is liable to have an increased length, and comparatively high parasitic capacitance CS is incidental to the data bus. Here, the data sensing circuit is a circuit provided for amplifying a data signal read out from each memory cell. In order to prevent a delay in operation after transition from the circuit waiting condition to the circuit operating condition arising from the presence of parasitic capacitance CS, a MOS transistor is provided through which bias current for keeping the potential of the data bus flows. While the MOS transistor is set so as to have a sufficiently small gate width, the bias current thereof is 1 mA or so, which is still higher than the steady currents I1a, I2, I3 and I4 described above.
As the storage capacity of a semiconductor memory device, particularly an SRAM, increases, the importance of defect analysis (analysis of causes of rejection) when the yield is decreased by various factors including fine leakage at memory cells and incomplete pattern formation progressively increases. In particular, in the defect analysis upon a decrease in yield, it is necessary to investigate various characteristics of the current consumed by the memory cell array, for example, the voltage characteristic, the temperature characteristic, the difference depending upon the write data of "0" and "1", and other factors. However, in the case of a semiconductor memory device having a power source voltage step-down circuit as described above, since a steady current higher than the current which is consumed by the memory cell array also flows through the voltage step-down circuit during waiting for circuit operation, even if the consumed current of the semiconductor memory circuit is measured simply, the current consumed by the memory cell array cannot be determined. Further, even if the power source voltage to be supplied from the outside is varied, the voltage actually applied to the memory cell array cannot be varied due to the presence of the voltage step-down circuit; consequently, the voltage characteristic of the memory cell array cannot be measured. Accordingly, it is very difficult to perform defect analysis upon decrease in yield.


A flotation device for maintaining a watercraft in a floating condition is provided. The flotation device comprises an elongated housing mounted to the watercraft. A carrier is slidably received within the housing with the carrier having a first and second cover channel and a bladder retaining slot. A first collapsible tubing is receivable within the first cover channel. An elongated cover is releasably secured within the first cover channel and the second cover channel. A space is defined between the carrier and the cover. A flotation bladder is receivable within the space with the flotation bladder having a bladder edge receivable in the bladder retaining slot. An inflation mechanism is connected to the first collapsible tubing and the flotation bladder for inflating the first collapsible tubing and for inflating the flotation bladder wherein upon inflation of the first collapsible tubing, the cover is released from the first cover channel of the carrier and the flotation bladder moves the first edge of the cover in a direction generally away from the watercraft allowing the flotation bladder to substantially completely inflate.

1. Field of the Invention
The present invention relates to flotation devices for watercraft and, more particularly, it relates to an automatically inflating flotation device that would prevent a watercraft from sinking. The flotation device would automatically inflate when a predetermined amount of water entered the hold of the vessel.
2. Description of the Prior Art
Boating is both a popular pastime and a vital commercial activity in much of the world today. A boat is often a substantial investment for the owner. In the case of commercial boats, the boat is often the livelihood of the owner of the boat. As a general concept, boats sink when the hull of the boat takes on water and the boat loses its buoyancy. This can happen if the hull is breached due to a collision with some object or in heavy waves if the boat is swamped.
A number of patents have been directed to inventions to prevent a boat from sinking, even if the hull was breached. Unfortunately, the previous devices for boat floatation have a number of problems such as being difficult to install and often require manual activation of the device. This is a major concern since many boats often sink unattended at the dock, not out on the open water.
The flotation device of the present invention solves these problems and others by being easy to install, either as a retrofit to an existing boat or during manufacture of the boat. In addition, the flotation device of the present invention is designed to automatically deploy when a pre-determined level of water is consistently in the hull of the vessel. The device will not deploy when water merely splashes to that level, preventing unneeded deployment in heavy seas. Once deployed the present invention will keep the boat afloat even if a complete flooding of the hull has occurred.
The primary aspect of the present invention is to provide an automatically deploying flotation device to keep the boat floating after water has partially filled the hull of the boat.
Another aspect of the present invention is to provide a flotation device that does not interfere with the looks or operation of the boat when not deployed.
Another aspect of the present invention is to provide for a flotation device that can be easily removed and a new one re-installed after deployment.
Another aspect of the present invention is to provide a device that is easy to manufacture and install.
An automatically inflating boat rail is disclosed. An inflatable bag is rolled into a tight spiral. The spiral is mounted inside a one or more piece flexible housing. The base of the housing is mounted to the outside of the hull. The base of the bag is attached to the base of the housing. The outer part of the housing is removably attached to the base of the housing, enclosing the rolled bag. One or more bags can be mounted in the housing. The bag has valves that are attached to safety valves. The safety valve is triggered by water in the hull reaching a given height in the hull. Once the safety valve is triggered, tanks of compressed inert gas are released into the system. The outer part of the housing is pushed off and the bags inflate and unroll. The bags can have internal chambers so that one part can be punctured without deflating the whole system.
The present invention is a flotation device for maintaining a watercraft in a floating condition. The flotation device comprises an elongated housing mounted to the watercraft with the housing having a first cover channel, a second cover channel, and a bladder retaining slot. A first collapsible tubing is receivable within the first cover channel. An elongated cover having a first edge and a second edge is secured to the housing with the first edge releasably receivable in the first cover channel and the second edge releasably receivable in the second cover channel. A space is defined between the housing and the cover. A flotation bladder is receivable within the space with the flotation bladder having a bladder edge receivable in the bladder retaining slot. Inflation means are connected to the first collapsible tubing and the flotation bladder for inflating the first collapsible tubing and for inflating the flotation bladder upon inflation of the first collapsible tubing wherein upon inflation of the first collapsible tubing, the first edge of the cover is released from the first cover channel of the housing and wherein upon inflation of the flotation bladder, the flotation bladder moves the first edge of the cover in a direction generally away from the watercraft allowing the flotation bladder to substantially completely inflate.
In addition, the present invention includes an emergency buoyant support for a watercraft. The emergency buoyant support comprises a base plate mounted to the watercraft and a cover removably attached to the base plate. A storage channel is formed between the base plate and the cover and an inflatable bladder is spirally wrapped within the storage channel wherein upon inflation of the inflatable bladder, the bladder moves the cover allowing the bladder to inflate.
Furthermore, the present invention includes a method for maintaining a watercraft in a floating condition. The method comprises mounting a housing to the watercraft with the housing having a first cover channel, a second cover channel, and a bladder retaining slot, positioning a first collapsible tubing within the first cover channel, covering the housing with a cover with the cover having a first edge and a second edge, releasably mounting the first edge of the cover within the first cover channel and the second edge within the second cover channel, defining a space between the housing and the cover, positioning a flotation bladder within the space, the flotation bladder having a bladder edge, mounting the bladder edge of the flotation bladder within the bladder retaining slot, inflating the first collapsible tubing, and inflating the inflation bladder.
In an embodiment of the present invention, the method further comprises positioning a second collapsible tubing within the second cover channel and inflating the second collapsible tubing prior to inflating the inflation bladder.
Other aspects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Automatic inflating boat flotation device


A method and apparatus are provided for operating a wireless communication device. The method includes the steps of providing a plurality of battery powered modules that are carried by a user and together operate as the wireless communication module (ensemble), detecting a battery reserve power level of a first module of the plurality of modules and transferring a processing function from the first module to a second module of the plurality of modules based upon the detected battery reserve power.

Wireless communication devices are generally known. Wireless devices may be divided by function into voice devices such as cellular telephones and data devices such as PDAs or portable computers with wireless interfaces. Recent advances also include a large number of "smart" portable wireless devices that are able to handle both voice and data and typically have a wide range of functional capabilities.
When a wireless device is activated, the device automatically begins searching for a local base station. In order to facilitate the search for a base station, the base stations may transmit identification messages on one or more control channels. In order to locate a control channel of a local base station, the device may scan a series of channels by individually stopping on each channel and decoding any information on the channel in an effort to determine if a currently scanned channel is a control channel of a local base station.
Once the device locates a control channel, the device may register its presence with the base station. Once registered, the device may remain tuned to the control channel to place outgoing messages and/or voicecalls or to receive incoming messages and/or voicecalls.
Such wireless communication devices are portable and therefore, they are typically dependent upon a battery. While many devices have a battery level indicator, the indication of low battery level can often be missed leading to the inconvenience of an inoperative device. The wider array of functional capabilities may lead to increased power demands and furthermore, the rate at which battery power is consumed may vary greatly depending on the types of function performed and the frequency of use of those functions.
In order to avoid the inconvenience of a dead battery many people carry a spare battery or form a habit of recharging their batteries each night. While such practices are effective, they are overly burdensome to the end user. Accordingly, a need exists for better methods of extending battery life in portable communication devices, particularly the multi-functional devices described above.

Method of optimizing power consumption in a wireless device


A system especially suitable for illuminating the front side of an object, as viewed by an observer is disclosed herein. This system includes a light pipe assembly having opposing forward and rearward faces; an arrangement for directing light into the light pipe assembly in a predetermined way; and an arrangement of optical components forming part of the light pipe assembly. This latter assembly is provide for reflecting substantially all of the light directed into the light pipe in a forward direction through the forward face of the light pipe. The light pipe assembly including the arrangement of optical components is substantially transparent to visible light or electro-magnetic wave of a particular wavelength in the direction across the opposing forward and rearward faces of the assembly such that the light pipe assembly can be positioned between the object being illuminated and the observer or the detector without in any significant way disrupting the observer's or detector's view of the object.

1. Field of the Invention
The invention relates generally to lighting systems and particularly to an efficient, flat and transparent front-lighting system suitable for a wide range of applications such as illuminating automobile meters, road signs, reflective displays, shopping windows, high lighting pictures, jewelry, and art work. It also functions as a see-through lighting system for dentistry and surgery operation, medical and biological inspection tools, and many other applications. It is particularly suitable for precision work in which the conventional method of lighting from the side causes shadows and the parallax effect.
2. Description of the Related Art
The incandescent lamp and the fluorescent lamp are two of the most often used light sources for illumination, although some other light sources, such as light emitting diodes and electro-luminance, are often used for special applications such as indicators for electronic instruments. Most of the light sources, including the fluorescent lamp and the filament of the incandescent lamp are non-transparent. Some of the light sources, in particular, lamps based on gas discharge, such as neon lamps, are transparent when they are in an off state and do not emit light. These light sources, however, still can not be used as transparent, direct front-lighting systems since, when emitting light and placed between the viewer and the object, they will emit an equal amount of light directly towards the viewer and will therefore make it extremely difficult, if possible at all, to observe objects placed behind it. As a result, by using the conventional lighting method, objects are always being illuminated from the side with respect to the line of sight. Here, it should be noted that transparent objects are sometimes illuminated from the rear to achieve clearer viewing. The transmissive microscope is one example that uses backlighting to avoid parallax associated with side lighting for precision inspection.
A serious problem associated with the side illumination method is difficulty in observing detailed features of an object because of shadows and parallax effects. Small objects in deep holes in some medical inspection techniques as well as precision scientific and mechanical studies are particularly difficult to observe with side lighting. As an example, a dentist very often has to use a rather sophisticated lighting system and at the same time requiring that the mouth of a patient be stretched to the limit in order to observe teeth in detail. Another major problem associated with side illumination is the low energy efficiency. Because a relatively long distance between the light source and the object has to be maintained, an area much larger than the size of the object usually has to be illuminated with side lighting.
As will be seen hereinafter, with the transparent front-lighting system of the present invention, the lighting system can be placed directly on top of the object so that all of the light is effectively used for illuminating the object. Transparent direct lighting is particularly valuable for some molecular biomedical studies that use ultraviolet (UV) light to observe molecules labeled with a fluorescent material. The direct lighting approach of the present invention is not only highly efficient in its use of UV light from a lamp but also has the added advantage that the output UV light is directed toward the object and away from the observer so that the operator will not be exposed to excessive UV light irradiation which is harmful to the operator's health. It is possible to use a beam splitter (which transmits approximately 50% of light and reflects the other 50% ) for transparent direct front illumination. However, a sophisticated and bulky, optical arrangement requiring precision alignment is necessary for such an approach. A beam splitter based transparent front lighting system is, therefore, not widely used in practical application.

Flat and transparent front-lighting system using microprisms


The present invention is a means for accessing blood vessels for the insertion of a guide wire while preventing the free release of blood. Specifically, a hollow, thin-walled metal tube typically having a sharp point at its distal end is joined at its proximal end to a transparent viewing section. The viewing section has a distal narrow lumen and a proximal chamber which has a cap at its proximal end. The cap encloses a pressure sealing means through which a guide wire can be passed. After the distal end of the metal tube is placed in an artery, blood will rush through the metal tube and into the viewing section. The air in the air-tight proximal chamber will alternatively be compressed between diastolic and systolic blood pressure. Feedback to the operator that the distal end of the metal tube is properly placed within an artery can be achieved by observing the reciprocating pulsatile motion of the blood column within the distal narrow lumen of the viewing section. When the proper pulsatile motion is observed, a guide wire can be passed through the sealing means in the cap, through the viewing section, through the metal tube and finally the guide wire will enter the lumen of the artery.

Interventional cardiologists and radiologists currently practice a wide range of procedures that require percutaneous access to the human vascular system. In many of these procedures, percutaneous access occurs at the site of the common femoral artery or vein at the groin for the purpose of passing guide wires and introducer sheaths. Catheters can then be advanced through these sheaths to many places within the human vascular system. One method for performing this procedure utilizes a hollow steel cannula with a separate sharpened stylet needle through its center which is pushed through skin and then completely through the common femoral artery. The stylet is then removed and the steel cannula is pulled back slowly until blood under arterial pressure squirts vigorously in a pulsatile manner out of the cannula's proximal end thus indicating that the cannula's distal end is properly placed within the artery. A guide wire is then placed through the cannula and advanced into the artery, and then the cannula is pulled out. A variety of introducer sheaths and/or catheters can then be advanced over the guide wire and into the arterial system.
Another method for accessing arteries is by means of an introducer needle with a sharpened distal end that does not use a stylet needle. This introducer needle is placed through the skin at the groin and advanced until the opening of its sharpened distal end lies within the arterial lumen. When this occurs, blood squirts forcibly in a pulsatile manner out of the needle's proximal end. The pulsatile blood flow indicates that the introducer needle is properly located in the artery so that a guide wire can be inserted through the introducer needle followed by the introducer sheaths and catheters to be used for the procedure.
The blood squirting out of the cannula at arterial pressure results in a considerable release of blood which can find its way into the eyes, nose, or other openings of health care workers in close proximity to the patient.
Besides being messy and causing unnecessary blood loss to the patient, the squirted out blood represents a risk to the health care workers who could be exposed to infectious diseases carried in the patients blood.

Vascular access device with air-tight blood containment capability


The power conversion apparatus includes an inverter circuit which converts a DC current into an AC current and have a U-phase, V-phase, and w-phase power semiconductor modules, and a capacitor module for smoothing the DC current. Each of the power semiconductor modules is configured separately and connected to a first bus bar. The first bus bar is configured with a first positive side bus bar, a first negative side bus bar, and a first insulation member arranged between the first positive side bus bar and the first negative side bus bar. The first bus bar includes a first to third terminals to which the U-phase, V-phase, and W-phase power semiconductor modules are connected, respectively, and a fourth terminal connected to a terminal of the second bus bar protruding from a surface of sealing material of a second bus bar.

Nowadays, a hybrid electric vehicle and an electric vehicle are spreading rapidly, and improvement of assembling productivity and downsizing are required for the power conversion apparatus. Generally, as a method for improving assembling productivity and downsizing, modularization of parts is employed. Modularization is carried out for a power semiconductor module and a smoothing capacitor module as described in Patent Literature 1 (JP 2009-219270 A).
Further downsizing is required for a power conversion apparatus for a vehicle, which increases the effect of heat transfer between modules. Therefore, it is required to lower the heat generation of each module.


A method includes collecting optical data from an unpatterned region including a first process layer. At least one optical parameter of the first process layer is determined based on the optical data associated with the unpatterned region. Optical data is collected from a patterned region including a second process layer. At least one characteristic of the patterned region is determined based on the optical data associated with the patterned region and the at least one optical parameter.

The disclosed subject matter relates generally to manufacturing and, more particularly, to incorporating film optical property measurements into scatterometry metrology.
There is a constant drive within the semiconductor industry to increase the quality, reliability and throughput of integrated circuit devices, e.g., microprocessors, memory devices, and the like. This drive is fueled by consumer demands for higher quality computers and electronic devices that operate more reliably. These demands have resulted in a continual improvement in the manufacture of semiconductor devices, e.g., transistors, as well as in the manufacture of integrated circuit devices incorporating such transistors. Additionally, reducing the defects in the manufacture of the components of a typical transistor also lowers the overall cost per transistor as well as the cost of integrated circuit devices incorporating such transistors.
The technologies underlying semiconductor processing tools have attracted increased attention over the last several years, resulting in substantial refinements. However, despite the advances made in this area, many of the processing tools that are currently commercially available suffer certain deficiencies. In particular, such tools often lack advanced process data monitoring capabilities, such as the ability to provide historical parametric data in a user-friendly format, as well as event logging, real-time graphical display of both current processing parameters and the processing parameters of the entire run, and remote, i.e., local site and worldwide monitoring. These deficiencies can engender non-optimal control of critical processing parameters, such as throughput, accuracy, stability and repeatability, processing temperatures, mechanical tool parameters, and the like. This variability manifests itself as within-run disparities, run-to-run disparities and tool-to-tool disparities that can propagate into deviations in product quality and performance, whereas an ideal monitoring and diagnostics system for such tools would provide a means of monitoring this variability, as well as providing means for optimizing control of critical parameters.
Semiconductor devices are manufactured from wafers of a substrate material. Layers of materials are added, removed, and/or treated during fabrication to create the electrical circuits that make up the device. The fabrication essentially comprises four basic operations. Although there are only four basic operations, they can be combined in hundreds of different ways, depending upon the particular fabrication process.
The four operations typically used in the manufacture of semiconductor devices are:                layering, or adding thin layers of various materials to a wafer from which a semiconductor device is produced;        patterning, or removing selected portions of added layers;        doping, or placing specific amounts of dopants in the wafer surface through openings in the added layers; and        heat treatment, or heating and cooling the materials to produce desired effects in the processed wafer.
The various layers used for forming the features have many specialized functions. Certain layers are used to form conductive features, others perform insulating features, and still others are intermediate layers used to enhance the functionality of the processing steps used to pattern and form the functional layers. In some cases, the ability of a layer to perform its intended function is based mostly on its physical properties, such as its material of construction and thickness, while the ability of other layers to perform their intended function rests on electromagnetic properties, such as refractive index, that may vary based on the particular process used to form the layer.
One technique for measuring characteristics of features of a semiconductor device is optical metrology, such as scatterometry. In scatterometry, a structure, typically including a grid pattern is illuminated with a light source. Measurements of light reflected from the structure are analyzed to determine characteristics of the feature. Generally, variations in the feature result in variations in the reflected light profile.
The accuracy of optical metrology techniques depends, at least in part, on the characterization of the optical properties of the thin films being analyzed (e.g., index of refraction and/or coefficient of extinction). Conventionally, optical properties are characterized outside the measurement domain and assumed to remain constant during subsequent measurements. In some cases, however, manufacturing variations (i.e., intentional or unintentional) can lead to changes in the optical properties of the thin film materials, rusting in a loss of accuracy for the optical measurements.
This section of this document is intended to introduce various aspects of art that may be related to various aspects of the disclosed subject matter described and/or claimed below. This section provides background information to facilitate a better understanding of the various aspects of the disclosed subject matter. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art. The disclosed subject matter is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.

Incorporating film optical property measurements into scatterometry metrology


An analogue-to-digital converter (ADC), comprising: an adaptive whitening filter configured to filter an analogue input signal and output a whitened analogue input signal; a first converter configured to receive said whitened analogue input signal and output a whitened digital signal; a controller configured to adapt the whitening filter based on the received analogue input signal.

Analogue-to-digital converters (ADCs) are known and used in a variety of applications. One particular application is within audio signal paths where it is desired to store and transmit audio in digital format. An ADC may therefore be arranged in an audio signal path to convert an analogue signal such as that detected by a microphone, into an equivalent digital signal, i.e. digital data, which may be stored or passed on for further processing.
In communications devices, such as mobile telephones, integrated microphones are required to have a relatively large dynamic range to cope with large-amplitude interfering signals such as wind noise. Consequently, there is a need for ADCs used in such devices to also have a large dynamic range to convert analogue signals over their full dynamic range.


Method for introduction of filling materials into porous bodies in which the filling materials in liquid form are brought into contact with the porous bodies and are distributed from at least one site within the porous body in this porous body.

Often in the production of ceramic materials first a porous body is produced by a thermal process step, such as, for example, sintering or pyrolysis, and is then compacted. This compaction can take place by pressing, that is, without adding another substance, or by one or more infiltration or impregnation steps, while the infiltration agent can remain unchanged and at least partially fills only the (open or accessible) pores, or the infiltration agent reacts at least in one part with at least one of the components of the porous body, with the formation of at least one chemical compound.
A field in which this method has acquired technical importance is the production of ceramic material based on silicon carbide, first a porous carbon body being produced which then, by a reaction with liquid silicon or a silicon-containing melt with for the most part preservation of the geometrical shape and dimensions (so-called "near net shape method") of the carbon body, is converted into a body which largely consists of a silicon carbide which has been formed by the reaction of carbon and silicon. At the conventionally used temperatures above the melting point of silicon up to 1700 ° C., the beta-modification of the silicon carbide which is stable at these temperatures is formed.
There are various ways of introducing liquid silicon into porous, carbon-containing bodies. U.S. Pat. No. 5,432,253 discloses placing the porous body which is to be impregnated jointly with silicon in lump form on a carbon cloth (fabric or felt) and heating everything together to the infiltration temperature, that is, a temperature at which the silicon is molten liquid and has a low enough viscosity to penetrate by way of the cloth into the porous body and to be distributed in it.
Another method is known from U.S. Pat. No. 4,626,516 in which a mold with infiltration holes and a reservoir with elementary silicon is used; a porous body is placed in the mold, and the holes are provided with carbon wicks, the wicks being in contact with the porous body and the reservoir. At the operating temperature above the melting point of silicon, the silicon migrates through the wicks into the porous body.
U.S. Pat. No. 4,737,328 discloses covering a porous body with a powder mixture of silicon and boron nitride, and heating the arrangement above the melting point of the silicon, its penetrating into the body, and the boron nitride powder then being brushed off. Another method is covering a porous carbon body with a moldable and hardenable mass of silicon powder and a binder according to patent application WO1982/04248 or patent application EP 0 995 730 A1 . The advantage there is supposed to be that the silicon is delivered exactly in the required amount. Finally, patent application DE 102 12 043 discloses placing the article which is to be infiltrated with silicon on wicks of carbonized wood, these wicks with their lower end dipping into a metal melt.
The problem which is common to all these methods is that the silicon melt is always supplied from the surface of the body to be infiltrated. Here, in the vicinity of the entry point there is always a great excess of silicon, while much less silicon is transported into the regions farther away. For two-dimensional delivery as in applications WO 1982/04248 or EP 0 995 730 A1 . liquid silicon is supplied over the entire covered surface, but a gradient forms over the thickness of the body to be infiltrated. These gradients lead to inhomogeneity in the infiltrated and potentially reacted bodies which occasions an intolerable imbalance, especially for parts turning at high speed, such as brake disks or clutch disks.

Method of introduction of filling materials in liquid form into porous bodies


On a transparent electrically insulating substrate, formed are a scanning line, and a gate electrode of a switching element, further formed are a gate insulating film, a semiconductor layer, an n+-Si layer to be formed into a source electrode and a drain electrode. After the patterning of the foregoing structure, the dielectric film is formed, and the portion corresponding to the contact hole is removed by etching, and photosensitive resin is applied to form the interlayer insulating film. Then, the transparent electrode is extended from the pixel electrode over the switching element, whereon a conversion layer and a gold layer for use in electrode are vapor-deposited. In this structure, an increase in capacitor between the pixel electrode and the signal line can be suppressed by the interlayer insulating film, and the transparent electrode functions as a top gate and release excessive electric charge. As a result, excessive electric charge can be released effectively in the double gate structure while suppressing an increase in capacitor between the pixel electrode and the signal line.

A known active matrix substrate for use in a liquid crystal display device, etc., includes a plurality of independently driven pixel electrodes arranged in a matrix form, and switching elements such as TFTs (Thin Film Transistors), etc., provided for respective pixel electrodes. In the liquid crystal display device adopting such active matrix substrate, an image is displayed by sequentially selecting the switching elements by scanning lines and reading potentials of signal lines into the pixel electrodes via the switching elements.
The foregoing active matrix substrate can be used for an image sensor. Examples of known image sensors adopting the active matrix substrate include: an image sensor including a conversion layer formed on an upper layer of the active matrix substrate, for directly converting incident electromagnetic wave such as a light beam, an X-ray, etc., into electric charge, wherein the electric charge generated from the conversion layer is stored in pixel capacitance at high voltage, and the electric charge is read out sequentially from the pixel capacitance. For example, Japanese Unexamined Patent Publication No. 212458/1992 (Tokukaihei 4-212458) published on Aug. 4, 1992, discloses an image sensor of the above type wherein electric charge as generated by the conversion layer is stored in auxiliary capacitance, and data (potential data) are stored in respective pixels in the form of electric charge according to the characteristics of an object. As in the case of the aforementioned liquid crystal display device, by sequentially scanning the scanning lines, for example, the data stored in a pixel selected by a scanning line is read out and transmitted via a switching element to a signal line, and an image projected to the image sensor is read out from a circuit such as an operation amplifier provided on the other end of the signal line.
The active matrix substrate, which is a precursor to the sensor in the foregoing example can be manufactured at low costs without requiring any additional facilities, because the manufacturing process for liquid crystal display devices can be used for the manufacturing process of image sensors only by adjusting the dimensions of the pixel capacitance and the time constants of the switching elements to be optimal for image sensors.
FIG. 6 is a cross-sectional view illustrating a schematic structure of a known example of the basic image sensor adopting an active matrix substrate. The structure illustrated in FIG. 6 is disclosed in AM-LCD' 99 "Real-time Imaging Flat Panel X-Ray Detector" by M. Ikeda, et al. As illustrated in FIG. 6, the active matrix substrate of this sensor is prepared by forming a switching element 51 on a transparent insulating substrate 55, and further vapor-depositing thereon a conversion layer 66 and a metal layer 67 in this order. The switching element 51 is prepared by forming on the transparent insulating substrate 55, a gate electrode 56, an auxiliary capacitance electrode (not shown), a gate insulating film 57, a semiconductor layer 58, an n+-Si layer 59 to be patterned into a drain electrode, a metal layer 60 and a transparent electrically conductive film 61 to be patterned into a source signal line, and a protective film 62 in this order, thereby forming a substrate of the image sensor. The conversion layer 66 is provided for converting an X-ray into electric charge. The metal layer 67 is patterned into an electrode for use in applying a voltage to the conversion layer 66. In the foregoing structure, the transparent electrically conductive film 61 is patterned into the pixel electrodes for storing the electric charge as converted in the conversion layer 66.
In the image sensor, the electric charge is read out from respective pixel electrodes in contrast to the liquid crystal display device in which electric charge is applied to the pixel electrodes. Therefore, if a normal readout operation of a predetermined cycle is not performed due to any failure, or a trouble in signal readout program, unexpectedly large electric charge may be stored in the pixel electrode, and the resulting high voltage may cause a damage on the active matrix substrate. The foregoing problem is discussed in "Characteristics of dual-gate thin film transistors for applications in digital radiology" (NRC'96) in "Can. I. Phys. (Suppl)74 published in 1996, in which the following structure has been proposed as a solution to the problem. That is, a pixel electrode is extended over a switching element, so that the pixel electrode can be functioned as one of the gate electrodes of a dual-gate transistor, and at or above a predetermined threshold voltage, the transistor is switched on, and excessive electric charge is released.
The structure of an image sensor which is particularly effective in preventing the foregoing problem will be explained in reference to FIG. 7. As illustrated in FIG. 7, the image sensor has a so-called "mushroom structure" wherein pixel electrodes 72 and source lines 71 are formed in different layers so as to be insulated by an insulating layer 73 formed in between, so that the entire channel region W of a transistor 74 is covered with the corresponding pixel electrode 72. In FIG. 7, the reference numerals 75, 76, 77, 78 and 79 indicate a gate electrode, a drain electrode, an auxiliary capacitance, a conversion layer and a semiconductor layer respectively.
The foregoing structure of Waechter, et al, illustrated in FIG. 7 is effective for the high voltage protection in the pixel electrodes 72. As to the size of the pixel electrodes 72, however, significant improvement from the aforementioned active matrix substrate illustrated in FIG. 6 cannot be expected. It is generally known that the larger is the area occupied by the pixel electrodes 72, the more efficiently, the electric charge generated from the conversion layer 78 can be collected in the pixel electrodes 72. In the generally used active matrix substrate, however, there is a limit for an increase in size of each pixel electrode as pixel electrodes are arranged in a plane with certain intervals from source bus lines.
In the foregoing structure of FIG. 7 wherein the insulating film 73 is formed between the source line 71 and the pixel electrodes 72, the pixel electrodes 72 can be formed over the source lines 71 while maintaining the insulation between them. In this state, the electrostatic capacitance is generated between the pixel electrodes 72 and the source lines 71, and an overall capacitance of the source lines 71 when seen from the side of the signal readout circuit increases, and a noise of the readout signal is increased, resulting in lower signal to noise (S/N) ratio. For the foregoing reasons, the structure of FIG. 7 would not offer any significant improvement in size of the pixel electrodes 72 from the conventional active matrix substrate.
In the X-ray image sensor, generally a large pixel capacitance is ensured. For this reason, the capacitance between the pixel electrode 72 and the source line 71 becomes a load capacitance to the source line 71 directly. On the other hand, internal noise generated in the signal readout amplifier is amplified by a gain in proportion to the ratio of the capacitance of the source line 71 to the feedback capacitance. It is therefore effective to reduce the capacitance of the source line 71 for a reduction in internal noise.
Further, an increase in capacitance of the source line 71 may cause variations in potential of the source line 71 corresponding to the capacitance CsD (per pixel) between the pixel electrode 72 and the source line 71 with changes in pixel potential corresponding to the part of the image irradiated with an X-ray. For example, when reading out signals via the source line 71 with a selection of certain scanning line, the electric charge is kept being stored in other pixel electrodes, while the electric charge in positive polarity and in proportion to the capacitance CsD are being stored in the source line 71. The amount of the electric charge to be stored in the pixel electrodes and the source line 71 differ depending on the image on an entire screen, thereby presenting a problem that a so-called crosstalk is generated when reading out signals as being affected by pixel electrodes aligned in direction parallel to the source line 71.
In order to reduce the capacitance of the source line 71, for example, an image sensor adopting an interlayer insulating film made of photosensitive resin has been proposed, for example, in "Similarities between TFT Arrays for Direct-Conversion X-Ray Sensors and High-Aperture AMLCDs" (SID 98 DIGEST) by W.den Boer, et al, published in 1998.
However, W.den Boer, et al does not refer to the dual-gate structure.

Image sensor and method of manufacturing the same