A downhole electrical power generator. A downhole electrical power generating system includes a flow restricting device which variably restricts flow through an opening, the restricting device vibrating in response to flow through the opening and the restricting device thereby alternately increasing and decreasing flow through the opening; and an electricity generating device which generates electricity in response to vibration of the restricting device. Another downhole electrical power generating system includes a flow restricting device which vibrates in response to flow through an opening, the restricting device thereby alternately increasing and decreasing flow through the opening, a pressure differential across the restricting device variably biasing the restricting device to increasingly restrict flow through the opening, and the pressure differential alternately increasing and decreasing in response to respective alternate increasing and decreasing flow through the opening; and an electricity generating device which generates electricity in response to vibration of the restricting device.

A wide variety of downhole well tools may be utilized which are electrically powered. For example, flow control devices, sensors, samplers, packers, instrumentation within well tools, telemetry devices, etc. are available, and others may be developed in the future, which use electricity in performing their respective functions.
In the past, the most common methods of supplying electrical power to well tools were use of batteries and electrical lines extending to a remote location, such as the earth's surface. Unfortunately, some batteries cannot operate for an extended period of time at downhole temperatures, and those that can must still be replaced periodically. Electrical lines extending for long distances can interfere with flow or access if they are positioned within a tubing string, and they can be damaged if they are positioned inside or outside of the tubing string.
Therefore, it may be seen that it would be very beneficial to be able to generate electrical power downhole, e.g., in relatively close proximity to a well tool which consumes the electrical power. This would preferably eliminate the need for batteries, or at least provide a means of charging the batteries downhole, and would preferably eliminate the need for transmitting electrical power over long distances.


In a lamp lighting ballast which generates a lamp lighting signal for a lamp, provided is a striation elimination circuit to increase the lumen output frequency for elimination of visual striations which may occur within the lamp. An even harmonic signal generator is configured to generate an even harmonic waveform, and an injection point is configured to receive the even harmonic signal into the lamp lighting system. The injection point is located at a location wherein the even harmonic signal alters the lamp lighting signal from a symmetric signal configuration to a high content even harmonic signal configuration prior to being received by the lamp.

The present application is directed to improving the visual appearance of gas discharge lamps, and more particularly, to the elimination of visual striations which may occur in gas discharge lamps.
Generally, a gas discharge lamp will have an elongated gas-filled tube having electrodes at each end. A voltage between the electrodes accelerates movement of electrons. This causes the electrons to collide with gas atoms producing positive ions and additional electrons forming a gas plasma of positive and negative charge carriers. Electrons continue to stream toward the lamp's anode electrode and the positive ions toward its cathode electrode sustaining an electric discharge in the tube and further heating the electrodes. The electric discharge causes an emission of radiation having a wavelength dependent on the particular fill gas and the electrical parameters of the discharge.
A fluorescent lamp is a gas discharge lamp in which the inner surface of the tube is coated with a fluorescent phosphor. The phosphor is excited by the ultraviolet radiation from the electric discharge and fluoresces, providing visible light.
During operation of a gas discharge lamp, such as a fluorescent lamp, a phenomenon known as striations can occur. Striations are zones of light intensity, appearing as dark bands. This phenomenon can give a lamp an undesirable strobing effect. An example of the striation phenomenon is shown in FIG. 1, which depicts a linear fluorescent lamp 10. In one embodiment lamp 10 may employ Krypton (Kr) as a buffer gas to improve the efficacy of the lamp. In FIG. 1, lamp 10 has striation zones 12 which appear as the dark bands moving along the length of the lamp.
A variety of theories as to why striations occur have been set forth. For example, in U.S. Pat. No. 5,001,386 to Sullivan, it is stated that striations are believed to occur as a result of high-frequency currents re-enforcing a standing wave of varying charge distribution between the lamp electrodes.
Sullivan attempts to solve the striation problem by injecting a dc component superimposed on top of a driving ac current. A disadvantage to this technique, is the requirement that existing typical high-frequency ballasts in the marketplace must be removed and replaced with a unique ballast capable of injecting the dc bias component. Also, adding the dc bias may damage the lamp, by moving mercury in the lamp to one end, creating an unbalanced light output. It is also suggested that increasing the crest factor in a lamp lighting system will eliminate the visual striations. However, increasing the crest factor may also increase the stress on a lamp, which will lead to a shorter lamp life.
Another alternative was proposed by Kachmarik et al., U.S. Pat. No. 6,465,972 ('972) which provides an amplitude modulation circuit placed in operative connection with the lamp input line. The amplitude modulation circuit is configured to periodically modulate amplitudes of the lamp input signal prior to the lamp input signal being received by the gas discharge lamp. Operation of the amplitude modulation circuit results in a periodic amplitude modulation of the lamp current to eliminate visual striations otherwise occurring in the lamp.
Yet a further attempt to eliminate striations is proposed in U.S. application Ser. No. 09/681,994 (U.S. Publication No. 2003-0015970A1) to Nerone. In this application a ballast is designed to convert an AC system power source to a DC voltage on a DC bus included within the ballast circuit. An inverter circuit is provided in the ballast circuit in operative connection with the DC bus to generate an asymmetric alternating current on a lamp input line. A gas discharge lamp is in operative connection to the lamp input line, configured to receive an asymmetric alternating current, thereby eliminating visual striations occurring in the lamp.

Striation control for current fed electronic ballast


Depth image compression is described for example, to enable body-part centers of players of a game to be detected in real time from depth images or for other applications such as augmented reality, and human-computer interaction. In an embodiment, depth images which have associated body-part probabilities, are compressed using probability mass which is related to the depth of an image element and a probability of a body part for the image element. In various examples, compression of the depth images using probability mass enables body part center detection, by clustering output elements, to be speeded up. In some examples, the scale of the compression is selected according to a depth of a foreground region and in some cases different scales are used for different image regions. In some examples, certainties of the body-part centers are calculated using probability masses of clustered image elements.

Depth images from depth cameras are increasingly used to detect people and objects in scenes for many applications such as to find positions of human or animal body-part centers, to find positions of objects in scenes and for other purposes such as medical image analysis. Processing the depth images is typically computationally expensive and time consuming.
Finding positions of human or animal body-part centers in image data such as depth images, color video images and other types of images may be useful in many application domains such as augmented reality, immersive gaming, human computer interaction and others. In many of these application domains body-part center positions are to be predicted in real-time and often the available image data may be noisy or incomplete. In some cases the computing resources available may comprise graphics processing units that are operable in parallel to give fast processing times. However, this is not always the case. There is a need to reduce the amount of computation without significantly impacting accuracy and usability of the resulting body-part center positions.
Existing body-part position detection systems may involve several stages of computation. Typically a detection system is trained in advance using labeled image data.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known depth image compression systems.


A photographic subject authenticating device, a portable telephone, a photographic subject authenticating method and a photographic subject authenticating program are able to improve reliability of security with respect to disguise, and restrain electric power consumption. A controller of a photographic subject authenticating device for performing authentication processing for authenticating a photographic subject based on a photographic image provided by photographing the photographic subject is constructed so as to execute authentication repeating processing for also repeatedly executing the authentication processing after it is judged as in conformity by the authentication processing; repeating stoppage instruction receiving processing for receiving repeating stoppage instructions for stopping the repetition of the authentication processing by an input device; true and false judgment processing for comparing the received repeating stoppage instructions with normal instructions registered in advance, and making true and false judgments; and repeating stoppage processing for stopping the authentication repeating processing when the judging result of the true and false judgment processing is true.

1. Technical Field
This invention relates to a photographic subject authenticating device, a portable telephone, a photographic subject authenticating method and a photographic subject authenticating program for photographing a photographic subject such as the face of a person, the iris, a palm print, etc. and authenticating the photographic subject.
2. Background Art
Various kinds of authenticating systems such as a face authenticating system for photographing and authenticating the face, an iris authenticating system for photographing and authenticating the iris, a palm print authenticating system for photographing and authenticating the palm print of a hand, etc. are conventionally proposed as a system for authenticating the person in question.
In these authenticating systems, the photographic subject such as the face, the eye or the hand is photographed and authenticated. These systems are mounted to various devices such as a personal computer, a portable information terminal, an ATM or a vehicle, etc., and can be practically used.
However, for example, when disguise using a photograph, etc. is performed and an authenticating result is once conformed, a problem exists in that all subsequent use and operations of the device are allowed since it is the person in question.
A vehicle monitor for improving reliability of security is proposed to solve this problem (see patent literature 1). This vehicle monitor again performs the authentication even when the image of a crew member is repeatedly acquired and the authenticating result is once conformed. Thus, for example, it is possible to detect the disguise in a mounting state of a person face mask.
However, in this vehicle monitor, a user must be repeatedly photographed in a state correctly authenticated. Therefore, the problem of being inconvenient for the user is left.
Further, it is impossible to cope with a case in which the person in question allows others to utilize the vehicle by obtaining consent of the person in question. For example, a problem also exists in that no driver of the vehicle can be changed.
[Patent literature 1] JP-A-2004-276783

Photographic subject authenticating device, portable telephone, photographic subject authenticating method and photographic subject authenticating program


A system for accessing a resource locator (RL) associated with a resource wherein a RL search string is used to search a list of valid RLs to identify valid RLs similar to a predetermined specified RL. A list of valid RLs meeting criteria specified by the search string is generated and displayed for user review or selection.

The Internet provides access to many different sources of information. Many commercial concerns and organizations have recognized the value of the Internet in providing broad access to information concerning, for example, their respective products, services, location, contact information, purposes, goals, qualifications and more. The world wide web (WWW) is one component of the Internet that is widely used by people, companies or organizations to publish information in the form of web sites, or web pages. Often times, companies and organizations will adopt a domain name that is used, for example, as the uniform resource locator (URL) for accessing, for example, a web site associated with the particular company or organization. This domain/URL may correspond to, for example, the name of their company, organization, product line or related theme, for example. As a result, it is well known by many users of the Internet that when searching for information on a particular organization or company, the company name (product name, etc.) itself may in fact constitute the main part of the URL that would allow access to that company's/organizations web site. In view of this it is often common for a user to make a first attempt at accessing a company/organizations' web site by specifying, for example, the company or organization name, product name or common variations thereon as a part of the specified URL to be accessed using, for example, a web browser.
More particularly, as an example, where a company's name is, for example, "The Big Shop", a user may make a first attempt to access an associated web site by specifying a URL such as: "WWW.THEBIGSHOP.COM", or "WWW.BIGSHOP.COM". If this URL is valid, the web page that corresponds to the URL will be accessed, retrieved and displayed for the viewer to peruse. However, the web page accessed may or may not be a web page that is actually associated with the particular company "The Big Shop".
Thus, the first attempts of specifying a web site URL in this way may be unsuccessful in accessing the web page associated with the desired company, organization or product. As many parties may seek out the same domain name to be associated with their particular company, organization or web site, it is often common for a domain name that incorporates a particular company or organization name to already be in use and registered to another party. Thus, a party may have to adopt some near variation on their company or organization name in order to incorporate it into a domain name that is actually available for registration. These "close" variations in domain names often make it difficult for a user to specify the domain name that is associated with the company or organizations whose web page they desire to access.
As a result, a user may use a search engine to locate a URL associated with the desired company or organization. A user must then specify key words that will be used by the search engine to generate a list of web sites. These web sites may or may not be relevant to the web site the user is looking for.
Thus, it is often difficult to access the web site of a particular party, company or organization without conducting a search engine search, specifying appropriate search terms and reviewing a listing of resources that are nowhere near relevant to the sought after information.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.

System and method for locating a resource locator associated with a resource of interest

Hewlett-Packard Development Company, L.P.


A method for fabricating a semiconductor memory device includes the consecutive steps of consecutively depositing metallic, nitride and oxide films on an underlying insulating film, patterning the nitride and oxide films to allow the oxide film to have a patterned area smaller than the patterned area of the nitride film, patterning the metallic film by using the nitride and oxide films as a mask, forming a side-wall film having a tapered mesa structure on the oxide, nitride and metallic films, embedding the side-wall oxide film by an interlayer dielectric film, and forming a contact hole in the interlayer dielectric film and the underlying oxide film while using the side-wall oxide film as an etch stopper.

(a) Field of the Invention
The present invention relates to a method for fabricating a semiconductor device having a tapered-mesa side-wall film, and more particularly, to an improvement of the structure of an interlayer dielectric film embedding therein an interconnection layer.
(b) Description of the Related Art
A multi-layer interconnection structure is generally employed in conventional semiconductor devices, such as a DRAM, for reducing the occupied area of the semiconductor devices. The multi-layer interconnection structure increases the integration density of the semiconductor device in association with the fine fabrication processes. The resultant semiconductor devices having a higher integration density generally have a higher aspect ratio and a smaller distance between each adjacent two of the interconnects due to the smaller dimensions of the devices in the horizontal directions.
FIGS. 3A to 3E show consecutive fabrication steps of a process for fabricating a conventional multi-layer interconnection structure by using a two-layer hard mask. A metallic conductive layer 11a is first deposited on an underlying silicon oxide film 10, followed by deposition of the two-layer hard mask including an insulator film 12 and a silicon oxide film (oxide film) 13 consecutively as viewed from the bottom. The insulator film 12 may be a silicon nitride film (nitride film) having a sufficient etch selectivity relative to the oxide film 13. A photoresist film is then formed on the oxide film 13 by coating, followed by patterning thereof to obtain a photoresist pattern 14. The insulator film 12 and oxide film 13 are then etched by using the photoresist pattern 14 as a mask, to obtain the structure of FIG. 3A.
Subsequently, the photoresist pattern 14 is removed, followed by etching the metallic conductive film 11a to configure bit lines 11 having a specified width by using the insulator film 12 and oxide film 13 as a mask, as shown in FIG. 3B. Thereafter, as shown in FIG. 3C, another insulator film 15 is deposited on the entire surface, followed by etch-back thereof to configure side-wall films 16 on the bit lines 11a and corresponding insulator films 12, as shown in FIG. 3D. After this etching step, a portion of the oxide film 13 may be left on the insulator film 12, as illustrated by the dotted line in FIG. 3D.
After forming the side-wall film 16, an interlayer dielectric film 17 is deposited to entirely embed therein the bit lines 11, insulator films 12 and side-wall films 16, as shown in FIG. 3E. It is to be noted that a defect, or void, is formed in the interlayer dielectric film 17 between side-wall films 16 (or bit lines 11). The void is likely to occur in the case of a smaller distance between the bit lines 11 and the case of a higher aspect ratio of the insulator films 12 and side-wall films 16. In other words, a defective embedding structure of the interlayer dielectric film 17 may occur in the case of a smaller distance between the adjacent side-wall films 16 and a larger depth of the side-wall films 16.
The two-layer hard mask may be replaced by a single-layer hard mask for patterning the bit lines 11. FIGS. 4A to 4F show consecutive fabrication steps of another process using the single-layer hard mask in another conventional technique.
A metallic conductive film 11a and an insulator film 12 are consecutively formed on an underlying oxide film 10. Thereafter, a photoresist film is formed on the insulator film 12 by coating, followed by patterning thereof to form a photoresist pattern 14. By using the photoresist pattern as an etching mask, the insulator film 12 is etched, as shown in FIG. 4A. After removing the photoresist pattern 14, the metallic conductive film 11a is then patterned using the insulator film 12 as a mask to configure bit lines 11 having a specified width just under the insulator film 12, as shown in FIG. 4B. An insulator film 15 is then deposited on the entire surface, as shown in FIG. 4C, followed by etch-back thereof to configure side-wall films 16 on both sides of the bit line 11 and the insulator film 12, as shown in FIG. 4D.
After the etch-back step, the insulator film 12 on the bit line 11 has a reduced thickness compared to the case using the two-layer hard mask, as illustrated by the dotted line in FIG. 4D. Subsequently, an interlayer dielectric film 17 is deposited to embed therein the insulator films 12 and the side-wall films 16, as shown in FIG. 4E. In this case using the single-layer hard mask, since the space between adjacent side-wall films 16 has a smaller depth, the defective embedding structure of the interlayer dielectric film such as encountered in the case of the two-layer hard mask is less involved in this case.
After forming the interlayer dielectric film 17, the interlayer dielectric film 17 is etched while using the insulator film 12 and the side-wall films 16 as an etch stopper in an self-alignment etching technique in order to form a contact hole for receiving therein a contact, i.e., self-aligned contact, for a capacitor between the bit lines 11. In this case of the single-layer hard mask, there may arise a problem that a short-circuit failure occurs between the self-aligned contact and one of the bit lines 11, as illustrated in FIG. 4F, due to the insufficient thickness of the insulator film 12 which may cause an exposed surface of the bit lines 11 during after self-alignment etching.
It is to be noted that a defective embedding structure of the interlayer dielectric film is more likely to occur along with the development of the finer patterning process to reduce the space between adjacent interconnect lines. As described above, the two-layer hard mask causes the defective embedding structure due to the increased aspect ratio, wherein the space between the adjacent side-wall films has a larger depth. On the other hand, the single-layer hard mask may cause a short-circuit failure due to reduction of the thickness of the insulator film and thus reduction of the etching margin during etching for the contact hole receiving therein the self-aligned contact, although there is some improvement in the embedding structure itself.
Patent Publication JP-A-2000-31277 describes an improvement in the embedding structure formed by using the single-layer hard mask, wherein the embedding interlayer dielectric film is formed after removing the top corners of the insulator film on an aluminum interconnect line. The described technique can reduce the effective aspect ratio by increasing the space between the adjacent insulator films in the vicinity of the top thereof due to the removal of the top corners of the dielectric film. However, this technique does not solve the above problem of the short-circuit failure because the reduced thickness of the insulator film reduces the etch margin during etching for the self-aligned contact hole.

Method for fabricating a semiconductor device having a tapered-mesa side-wall film


The present invention relates to a method for transmitting formatted text from a streaming server 100 to a mobile client 101 using an RTP protocol in a mobile communication system. The formatted text comprises at least one text sample having an associated text sample format description. Further; the present invention relates to the streaming server 100 transmitting the formatted text, the mobile client 101 receiving a streamed formatted text and to a streaming system. To reduce the transmission overhead of conventional systems when transmitting streamed text in a wireless communication system, such as UMTS, using RTP, the streaming server 100 transmits only text sample format descriptions that are not already provided for a earlier text samples to the mobile client 101 when processing a text sample to be transmitted. The server maintains information on the text sample format descriptions transferred to the client in order to determine which of the text sample format descriptions have already been provided.

The 3GPP (3rd Generation Partnership Project) adopts IETF (Internet Engineering Task Force) standardized protocols like RTP, UDP, IP for the transport and packet-switch codecs like AMR (Adaptive Multi-Rate) and H.264 (MPEG 4 part 10) for encoding media. The 3GPP Packet Switched Streaming Services (see "Universal Mobile Telecommunications System (UMTS); Transparent end-to-end streaming service; Protocols and codecs", 3GPP TS 26.234 version 5.6.0 Release 5, September 2003, available at http://www.3gpp.org) use the RTP/UDP protocol stack to stream audio/video/text media.
RTP is a Real-Time Transport Protocol (see Schulzrinne et al., "RTP: A Transport Protocol for Real-Time Applicatons", RFC 3550, July 2003, all RFCs available at http://www.ietf.org) which is mainly used for real-time or near real-time communication, i.e. communication with relaxed delay constraints. It provides information on the timing of the media it carries and also allows re-ordering and re-assembling at the receiver.
An integrated part of the protocol is RTCP (Real Time Control Protocol) which provides minimal reception information and loose group membership. RTP is generally used together with the RTP/AVP profile (see Schulzrinne et al., "RTP Profile for Audio and Video Conferences with Minimal Control", RFC 3551, July 2003) which defines the use of the RTP header fields and mapping tables for payload types, besides simple RTCP feedback timing rules.
UDP (Postel, "User Datagram Protocol", RFC 768, August 1980) is the User Datagram Protocol used to transport RTP packets. UDP is commonly used when an unreliable communication is appropriate for the given media, as is the case for streaming applications. The protocol stack RTP/UDP is used because the timing constraints of the media don't usually allow reliable communication, e.g. by using TCP (Transmission Control Protocol).
In RTP, packetization schemes (payload formats) for existing media formats (codecs) are specified in the Internet Engineering Task Force Audio/Video Transport Working Group (IETF AVT WG). There is, for example, a payload format for AMR encoded speech data, and another one for H.264 video.
The payload format defined in Helistrom, "RTP Payload for Text Conversation", RFC 2793, May 2000, may be used to transmit conversational text but the format does not allow carrying any additional information on the decoration of the text characters. The decoration is for example the font used, the background color, the scroll or the karaoke movement. It does not allow spatial synchronization with other media, like it is needed e.g. for subtitling of video sequences. In summary, the 3GPP timed text (see 3GPP TS 26.234, in particular Appendix D.8a) offers a much wider range of functionalities which is not supported by other standardized codecs.
Rey et al., "RTP Payload Format for 3GPP Timed Text", draft-ray-avt-3gpp-tt-01.txt, IETF AVT WG, September 2003, available at http://www.ietf.org suggests a payload format for the transmission of timed text using RTP. However, the payload format provides solely means for out-of-band transmission of sample description information and does not address the problem of in-band transmission of sample description information in detail. The in-band transmission of sample description suggested by Rey et al. requires transmitting each sample description together with its associated text sample and therefore can not solve the problems outlined below.
In the present invention, in-band may be understood in the context of a signaling channel. In general, the sample descriptions represent pure signaling information or metadata. The text may be considered the actual data. Thus in-band means that the signaling, i.e. the sample descriptions, is transmitted in the same session as the data, i.e. the text samples. Please note that the text samples do not contain SPLDESC, THDR or FHDR headers, just text strings and modifier boxes (see 3GPP TS 26.234) are transmitted. Out-of-band signaling may be therefore understood as sending the sample description using another session or protocol than the one used for transmitting the data, e.g. SDP.
When streaming 3GPP Timed Text, it is typically the case that the steamed text samples refer to one and the same sample description entries. After a given amount of time all the possible sample descriptions have already been transmitted at least once. The text samples repeatedly refer to these sample descriptions and so the sample descriptions must be transferred over and over again from sender to receiver since the sender does not know which packets were received by the receiver. Further, 3GPP TS 26.234 and the method proposed In Rey et al., "RTP Payload Format for 3GPP Timed Text" both require that each text sample is always transmitted along with its associated sample description. Hence, in conventional systems the transmission overhead due to transmitting, all sample descriptions of a 3GPP file is large. Further, this overhead is especially undesirable in case of providing streaming to a mobile client over a radio link scarce in its resources.

Optimized transmission of text sample format description for streaming timed text


A recording head for use with a storage medium is provided. The recording head includes a substrate, a magnetic pole, a first magnetic bias structure positioned on a first side of the magnetic pole, and a second magnetic bias structure positioned on a second side of the magnetic pole, Spacer material is positioned between the magnetic pole and the first magnetic bias structure and between the magnetic pole and the second magnetic bias structure.

The present invention relates generally to the field of data storage and retrieval systems. More particularly, the present invention relates to assisting operation of a recording head.
In an electronic data storage and retrieval system, a transducing head can include a writer for storing information on a magnetic disc and a reader for retrieving the magnetically-encoded information from the magnetic disc. In a magnetic environment, the reader can include two shields and a magnetoresistive (MR) sensor positioned between the shields. Magnetic flux from the surface of the disc causes rotation of the magnetization vector of a sensing layer of the MR sensor, which in turn causes a change in electrical resistivity of the MR sensor. This change in resistivity of the MR sensor can be detected by passing a current through the MR sensor and measuring a voltage across the MR sensor. External circuitry then converts the voltage information into an appropriate format and manipulates that information as necessary.
The writer portion can include a top and one or two return poles. The return poles are separated from the top pole at an air bearing surface of the writer by a gap layer, and which are connected to each other at a region distal from the air bearing surface by a back gap, and which are connected to each other at a region distal from the air bearing surface by a back gap closer or back via. Positioned between the top and return poles are one or more layers of conductive coils encapsulated by insulating layers. The writer portion and the reader portion are often arranged in a merged configuration in which a shared pole serves as both the top shield in the reader portion and a bottom pole in the writer portion.
To write data to the magnetic media, an electrical current is caused to flow through the conductive coils to thereby induce a magnetic field to emanate from the top pole. By reversing the polarity of the current through the coils, the polarity of the data written to the magnetic media is also reversed. The track width of the written data is defined by the width of the top pole near the write gap at the air bearing surface.
In a magnetic recording, it is desirable to improve the areal density at which information can be recorded and reliably read. Perpendicular recording designs have the potential to support higher areal densities on storage media due to the way magnetic transitions are stored on the media and because a larger write field can be generated than is the case in longitudinal recording. In perpendicular recording systems, the magnetic transitions are stored perpendicular to a surface of the disc, which ultimately utilizes less disc space. A perpendicular recording head can include a write pole, a leading return or opposing pole magnetically coupled to the write pole and/or a trailing return pole, and an electrically conductive magnetizing coil surrounding the write pole. When recording magnetic transitions on the media, current is passed through the coil to create a magnetic flux in the write pole. The magnetic flux passes through a hard magnetic layer to a soft under layer in the media and across to the opposing pole. The magnetic flux creates transitions on the media. Perpendicular pole tips and parts surrounding the pole tips can create large magnetic fields even in a state when the writing current is turned off, which is referred to as a remnant state. The magnetic field remaining in the pole tip can adversely effect the transitions on the media, which can cause erasure of bits on the media. A design to assist operation of the pole tip and also prevent extraneous magnetic fields from erasing bits on the media is thus desired.


A device consisting of a container which is partially submerged in the sea which may be buoyant and connected to the seabed with cables or mounted on a platform and whose interior is connected to its exterior via pipes where in response to the passing of waves is filled and emptied through these pipes. The force of the water flowing through the pipes causes turbines to rotate thus generating electricity which may be transmitted to land. These turbines may be turbines which rotate in different directions depending on the direction of water flow or turbines which maintain the same direction of rotation irrespective of the direction of water flow.

1. Field of the Invention
The energy of ocean waves is immense and one of the largest renewable resources of energy that can be harvested by mankind. The US DOE estimate that the total power of waves breaking on the world's coastlines is 2 to 3 billion kW. Ocean wave energy is useful to mankind not only due to its energetic potential but also, unlike wind, is less intermittent as it is not reliant on local weather conditions and may travel thousands of miles with little energy dissipation.
2. Description of the Prior Art
There have been many attempts to harvest wave energy. The main problems being:
1) The energy of the waves is greatest in open sea far from shore, for example in some areas off the North Atlantic ridge swell heights can average about 8 meters. Closer to shore, wave energy is dissipated due to bottom friction and diffraction effects. Under deep-water conditions installation of wave energy converters can be difficult and expensive. Shore based wave energy converters are easier to install but have lower theoretical capacity and a greater environmental impact.
2) Many wave energy converters use floats that bob up and down on the wave with relation to the seabed, this movement may be used to generate electricity. However these type of energy converters intrinsically only harvest a small proportion of the wave's energy even if erected in open sea.
3) A wave's energy could be regarded as linear, perpendicular and/or parallel to the gravity of the earth. The energy that is parallel to the earth's gravity can be looked at as alternating in direction. Some of the most common electricity generating methods are based on force moving in one direction that creates a rotation of magnets or coils of wire about a central axis (a generator or turbine). Many methods for converting wave energy to electrical energy, particularly float based systems, have low efficiencies when attempting to convert alternating linear energy to the unidirectional rotation of a generator shaft.
A successful ocean wave energy converter could therefore comprise some or all of the following. It should function whatever the direction of the waves, it should harvest a large amount of the total energy of the wave, it should convert the force of the wave of alternating direction to unidirectional rotation of a generator shaft and it should be relatively simple to construct in open sea and deep water.


An amusement water ride is provided including a water course for carrying one or more circular water rafts. The water course is provided with at least one downhill section for accelerating the water rafts into a splash point. A spin mechanism is provided near the top of the downhill section for imparting a spin to the water rafts as they move past the spin mechanism. The spin mechanism includes a movement retarding surface along one wall of the water course and a movement expediting surface along an opposite wall of the water course. The movement retarding surface is provided with a high friction coating which retards sliding movement in a downstream direction of the surface of the raft which contacts the movement retarding surface, and induces rotation of the raft and movement towards the opposite wall. As the raft rotates into contact with the movement expediting surface it encounters no frictional resistance, and the spin is accelerated by the force of gravity acting on the mass of the raft as it moves downhill. The spinning raft increases thrill and introduces uncertainty among the passengers regarding who will be in a position to be splashed when the raft hits the splash zone.

Among the most popular amusement rides, particularly in warmer climates and during the Summer season, are water rides. Most water rides involve a floatation device or vehicle which travels in a downstream direction along a chute or channel in which water flows. The channel is typically provided with curves and one or more downhill sections which enable the vehicle to achieve sufficient speed to impart thrill to, and splash water on, the passengers.
One such conventional flotation vehicle is a circular raft with an outer annular tube formed from rubberized material or the like, which is air filled and deformable, such as that shown, for example, in U.S. Pat. No. 4,696,251. Mounted inside the annular tube is a passenger platform including a plurality of passenger seats. This vehicle is free floating when the depth of water in the channel is sufficient, and is popular because it can bounce from one wall of the channel to the opposite wall, causing the vehicle to turn in unpredictable ways. However, the speed of the raft is typically determined by the speed of the water, and is relatively slow. Thrill can be imparted by allowing the raft to travel down an inclined, downhill section where the force of gravity can accelerate the vehicle until it encounters the pooled water at the base of the incline, causing the water to splash and spray upwards and outwards, often splashing the passengers. However, even with very steep or long inclined sections, the rafts tend to travel straight down the incline, allowing the passengers to prepare for the impact with the water at the base of the incline (the "splash point"), thus preventing the ride from being very thrilling.
Therefore, the need exists for providing a water amusement ride with more thrill, and in particular, for disorienting or otherwise preventing the passengers in the vehicle from anticipating the splash point.

Water raft amusement ride including a device for spinning a circular water raft


Provided is a method for diagnosing Alzheimer/s disease using a decomposed biomaterial. The method includes: preparing magnetic particles on which primary capture antibodies specifically bound to beta-amyloid are adsorbed; decomposing a biomaterial including beta-amyloid; binding the beta-amyloid to the primary capture antibodies; binding secondary capture antibodies labeled with a fluorescent material to the magnetic particles bound to the beta-amyloid to form a complex; disposing the complex in a channel region of a photo field effect transistor in which a photocurrent is changed according to the amount of incident light; and measuring the photocurrent changed by light excited from the complex to quantify the concentration of the beta-amyloid existing in the biomaterial.

The present invention disclosed herein relates to methods for diagnosing Alzheimer's disease, and more particularly, to methods for diagnosing Alzheimer's disease using a biomaterial.
As the average length of life increases globally in these days and the society structure enters the aging society, Alzheimer's disease that is the most common form of dementia, i.e., senile neurodegenerative disease, has drastically come to the fore as social-economic and medical issue. While the current medical techniques fail to treat Alzheimer's disease or stop pathologic progress, it is possible to alleviate the progression speed of Alzheimer's disease and thus treatment is focused on such alleviation. Up to the now since the early 1900s when this disease was found, studies on Alzheimer's disease have been performed in various fields such as biology, biochemistry, cognitive ethology, etc., and importance of early diagnosis of Alzheimer's disease begins to emerge in recent years. Early diagnosis and caring of Alzheimer's disease is the best way able to decrease psychological and financial burden and to improve the quality of life in terms of a social-economical aspect as well as a personal aspect.
An existing diagnosis of Alzheimer's disease depends on time-consumptive and complex evaluation methods, such as a clinical evaluation, psychological testing, brain imaging, discrimination from other neurodegenerative diseases, etc. In this regards, detection of a molecular level biomarker that may confirm the diagnosis of Alzheimer's disease, discriminate the pathological severity degree in patients, expect the progression rate of a disease in patients, and monitor the progression state is the most useful way. Such a molecular-level biomarker should have a neuropathological basic characteristic, and sensitivity and specificity that are second to the clinical diagnosis level. Also, the molecular-level biomarker may be said to be ideal when it has reliability and reproducibility and a sample including the biomarker therein is extracted while accompanying low cost, noninvasion and easiness. Examples of existing Alzheimer's disease-related samples may include skin tissue, rectum tissue, bone-marrow, spinal fluid, etc., and collection of these samples may be said to be unsuitable for regular clinical diagnosis.
For example, a brain imaging technique using a high resolution brain imaging apparatus is an existing diagnosis method of Alzheimer's disease. The early diagnosis method of Alzheimer's disease using the brain imaging technique studies the preciseness of the brain imaging apparatus by scanning the brain of a suspected Alzheimer's disease patient to measure abnormal accumulation of beta-amyloid protein and comparing and analyzing the measured results with autopsy results of brain tissue after death. However, since this image-based diagnosis method requires a patient to pay high cost and discrimination is performed in a state that brain contraction or damage is progressed, detection of a disease is late. Another representative diagnosis method is a diagnosis of spinal fluid and measures a change in amount of beta-amyloid protein in the brain and spinal cord. However, the inspection method of the brain and spinal cord itself is known to be a very painful method, and is blamed for dangerousness accompanied during the inspection.

Method for diagnosing Alzheimer's disease using biomaterial

ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE


A light-emitting device includes a substrate, and a plurality of light-emitting elements that are mounted on the substrate and each include an LED chip and a phosphor layer on a surface thereof. A maximum deviation in a value of a chromaticity coordinate x of light emitted from the plurality of light-emitting elements is not less than 0.0125.

1. Field of the Invention
The invention relates to a light-emitting device.
2. Related Art
A light-emitting element composed of an LED chip and a phosphor layer on a surface thereof is known (see, e.g., JP-A-2002-261325 and WO2003/034508). This type of light-emitting element has high light conversion efficiency since the phosphor layer is adjacent to the LED chip. In addition, color unevenness due to a viewing angle can be suppressed by forming the phosphor layer with a uniform thickness.


Front and rear wheels Tf, Tr of a motor vehicle driven by an engine 10 are connected through a differential control device 15 which is capable of varying the torque to transmit. When the turning radius of a predetermined one wheel or the motor vehicle is equal to or smaller than a predetermined turning radius, the transmission torque of the differential control device is decreased by a control device to prevent the tight-corner braking phenomenon from occurring. When the motor vehicle is stopped momentarily with the transmission torque being lowered, the control device maintains the transmission torque as it is, and the vehicle is then restarted with the transmission torque being lowered. Thus, when the motor vehicle which was stopped momentarily with a large steering angle is then restarted, the tight-corner braking phenomenon can be prevented from occurring from the beginning of the restarting.

In motor vehicles, during the traveling along a curve, the turning radiuses of front wheels become larger than those of rear wheels, so that the traveling distance of the front wheels become longer than those of the rear wheels. For this reason, in a four-wheel drive vehicle of the type that front and rear wheels are drivingly connected to be driven by an engine, a problem arises in that since the difference between the traveling distances of the front and rear wheels becomes large during the traveling along a curve with a small radius, a tight-corner braking phenomenon to act as if braking has been applied to the front wheels occurs to exert an adverse influence on the steerability. As measures to obviate the problem, there is known a technology which is disclosed in Japanese unexamined, published patent application No. 8-2278. This technology is to prevent the occurrence of the tight-corner braking phenomenon in the following way. That is, the wheel speeds of four wheels are detected by wheel speed sensors, and then, the speed difference is calculated between the outside front wheel and the inside rear wheel. When the speed difference is equal to or larger than a judgment value which corresponds to a speed difference made on a curve with a turning radius causing the tight-corner braking to occur and when the speed difference is smaller than another judgment value which corresponds to another speed difference made on a curve with the minimum turning radius, the motor vehicle is judged to be in a turning state with a large steering angle, so that the transmission torque of a limited differential clutch (serving as differential control device) for coupling the front and rear wheels is decreased to prevent the occurrence of the tight-corner phenomenon.
However, the foregoing technology involves the following problems. That is, as shown in FIG. 7, when the motor vehicle M which was traveling along a curve with a turning radius equal to or smaller than a turning radius (hereafter simply as "tight-corner turning radius) which causes the tight-corner braking phenomenon to occur, is stopped temporarily at a position (A) and then is restarted, the tight-corner braking phenomenon occurs to adversely influence the steerability until the motor vehicle reaches another position (B) advanced somewhat from the stop position (A). Further, the motor vehicle suffers a shock when the tight-corner braking phenomenon is released at the position (B).
The causes for this are explained as follows. The rotational speeds of the wheels detected by the wheel speed sensors decrease to zero when the motor vehicle is stopped temporarily at the position (A), and since the judgment that the vehicle is in a turning state along a curve with a radius smaller than the tight-corner turning radius is reversed, the transmission torque of the differential control device is increased to bring the front and rear wheels into direct connection. Accordingly, by detecting the rotational speeds of the wheels by the wheel speed sensors after the restarting and then by calculating the speed difference between the outside front wheel and the inside rear wheel, it is judged that the vehicle is turning with a large steering angle to travel along a curve of a smaller radius than the tight-corner turning radius, and until so judged, the tight-corner braking phenomenon occurs to accumulate its stress in a power transmission mechanism between the front and rear wheels due to the competing rotations of the front and rear wheels depending on the difference between the traveling distances. Then, since it is judged at the position (B) that the vehicle is turning with a large steering angle along a curve of a smaller radius than the tight-corner turning radius, the transmission torque of the differential control device is decreased to release the tight-corner baking phenomenon. At this time, the stress accumulated in the power transmission mechanism is released instantaneously, so that the shock is given. This problem occurs not only when the motor vehicle M is restarted after being stopped temporarily, but also when the vehicle speed is increased again after being lowered to decrease the wheel speeds of the respective wheels to lower speeds than those which cannot be detected by the wheel speed sensors.
The object of the present invention is to solve the aforementioned various problems by performing a control of preventing the tight-corner braking phenomenon from occurring from the beginning of a restarting when the vehicle is restarted after being stopped temporarily in a control state that the occurrence of the tight-corner braking phenomenon is being prevented by decreasing the transmission torque of a differential control device for coupling front and rear wheels.


The present invention provides a biologically active substance secreting hybrid gel, which consists essentially of a biopolymeric gel and cells containing an expression vector with a gene encoding the biologically active substance to produce the substance. According to the present invention, it is possible to develop a gene therapy by skin transplantation allowing stable drug medication for a long time; alleviating pains of patients; and allowing fine adjustment of the dosage and control of genes externally without using retrovirusderived vector that tend to invoke the risk of mutation to wild types as in the conventional prescription.

1. Field of the Invention
The present invention relates to biologically active substance-secreting hybrid gel. More particularly, the present invention relates to a new hybrid gel which secrets a biologically active substance, and is useful as an external-use prescription such as an artificial skin used in the treatment of various difficult-to-cure diseases requiring long-term and continuous medication of physiological active substances in order to maintain biological functions.
2. Description of Related Art
Three methods are available to cure diseases which are caused by the loss or decrease in the functions of human cells for any reason. Namely, the lost or decreased functions are compensated for by
1) drug medication,
2) transplantation of organs/tissues or cells, or
3) gene therapy
Insulin dependent diabetes mellitus, for example, is caused by the destruction of the xcex2-cells, which produce insulin having the function of reducing the blood sugar level, and which occur in the islets of Langerhans of the pancreas. Patients who suffer from insulin dependent diabetes mellitus have a high blood sugar level, and as a result, the concentration of sugar in their urine increases. When the blood sugar level remains high, the functions of various human cells are damaged, causing serious complications.
It is thus necessary to externally dispense insulin and control the blood sugar level in order to cure the insulin dependent diabetes mellitus patients. Insulin dependent diabetics must have insulin doses administered several times every day for life. This is a serious physical and mental agony to the patient, and in addition, self-medication always involve risk of life because of possible mis-dispensing.
One of alternative methods to self-medication of insulin in transplantation of the pancreas or the islets of Langerhans (K. Kubota and Y. Idezuki, Nippon Rinsho: in Japanese, 48:1052, 1990). However, this treatment has a number of problems, such as, for example, few donors, difficulty of controlling immunorejection caused by the transplanted pancreas or the tissues, complicated surgical operations for transplantation requiring techniques of a high level, and hazards involved in the operation.
Gene therapy is one of the most exciting medical technique to being employed solve the above problems, and various gene therapies are being clinically tested for treating patients having serious diseases in the United States and other countries in the 1990s (N. K. Summers, Biotechnology 12;42, 1994). A method of treating diabetes based on the above technique has been proposed (R. F. Selden et al, The New England Journal of Medicine, 317(17): 1067, 1987). In this particular method, and insulin gene is introduced into culture cells, and the cells are transplanted to the body of the patient in order to assure continuous secretion of insulin produced by the introduced gene. This method has a number of problems such as, for example, difficulty of controlling secretion of insulin from the transplanted insulin producing cells and inability of removing the transplanted cells later from the body. It is generally known that the gene therapy is a promising and advanced medical technique for not only insulin dependent diabetes mellitus and genetic diseases such as serious immune deficiency diseases but also cancer, AIDS, and other hard-to-cure diseases. For this reason, many approaches have been proposed and gene therapy is actually being conducted in practical clinical cases. Most of these gene therapies use retrovirus-derived vectors to introduce genes into the cells utilizing cell infection of the virus.
This technique to use retrovirus-derived vectors has the drawback that the effectiveness of gene introduction depends on the affinity of the virus to the cells, and there is a possibility that the deactivated virus vectors will transform into wild retroviruses. In addition, conventional gene therapy generally has a problem in there being difficulty of controlling the introduced genes externally.
The present invention intends to provide a new art of transplanting cells containing a gene which encodes biologically active substance into the skin and controlling the expression of the gene externally. More specifically, the present invention intends to solve the problems of the prior art by transplanting biologically active substance-producing cells to the skin of a human body as a hybrid gel (cell-incorporating gel).
The present invention provides a biologically active substance-secreting hybrid gel, which consists of biologically active substance-producing cells and a biopolymeric gel.
In the case of said hybrid gel, a preferable embodiment is that the biologically active substance-producing cells are enclosed in or laminated on the biopolymeric gel, or laminated on the biopolymeric gel enclosing the biologically active substance-producing cells.
The present invention also provides a biologically active substance-secreting hybrid gel, which consists of biologically active substance-producing cells, animal skin cells and biopolymeric gel.
In the case of said hybrid gel, a preferable embodiment is that the animal skin cells are laminated on the biopolymeric gel enclosing the biologically active substance-producing cells; the biologically active substance-producing cells are laminated on the biopolymeric gel enclosing the animal skin cells; the animal skin cells and the biologically active substance-producing cells are laminated on the biopolymeric gel; or the animal skin cells or the biologically active substance-producing cells are laminated on the biopolymeric gel enclosing the animal skin cells and the biologically active substance-producing cells.
Furthermore, in the case of the biologically active substance-producing cells being enclosed in the biopolymeric gel, said cells are enclosed together with meshy material or porous membrane.
In the present invention, moreover, the biologically active substance-producing cells may be skin cells (i.e., skin fibroblasts or skin epidermal cells) which contain an expression vector recombinant with a DNA sequence encoding the biologically active substance such as insulin. And, said expression vector may be plasmid vector pBMG-neo-ins possessing insulin CDNA and neomycin resistance gene, or plasmid vector pRIS-proins-Ifur-IIfur-B10D which possesses mutant insulin gene expressing stable insulin by the action of furin.
According to the present invention, it will be possible to develop a gene therapy by skin transplantation allowing stable drug medication for a long time; alleviating pains of the patients; and allowing fine adjustment of the dosage and control of gene externally without using retrovirus-derived vectors that tend to invoke the risk of mutation to wild types as in the conventional technique.
The cells used in the invention are enclosed in or laminated on the biopolymeric gel of the present invention and produce a biologically native substance necessary for or deficient in the body, and the substance is continually secreted into the body. The production of biologically active substance is increased when meshy material or porous membrace, etc. are enclosed in the gel together with the biologically active substance producing cells. Thus the hybrid gel of the present invention can be effectively used as, for example, an external-use prescription such as an artificial skin. The gene expressing biologically active substance is introduced to the cells by, for example, plasmid vector, and thus, unlike conventional gene therapy, no risk of conversion into wild retro-viruses owing to the retrovirus-derived vectors is involved. In addition, the introduced gene can be easily controlled externally because the gene-containing cells are transplanted to the skin.
The following functions are available in concrete:
1) After transplantation, the biologically active substance is dispensed for a long time stably without the knowledge of the patient. This dramatically reduces the physical and mental agony of the patient subject to repeated medication in the conventional treatment.
2) A very simple surgery is used to transplant or remove the hybrid gel of the present invention from the skin. For this reason, the quantity of artificial skin to be transplanted can be adjusted at any time freely while watching the process condition of the treatment, It is thus easy to determine optimum conditions for treatment.
3) The rate of substance secretion from the cells in or on the gel can be controlled by means of inducible promoters to control expression of the DNA sequence encoding the biologically active substance and various induction stimuli (hormones, heavy metals, temperature, etc.) applied to the transplanted artificial skin. This allows fine adjustment of the substance secretion rate.
4) The transplanted cells are enclosed in or on the gel and thus are hardly affected by immunorejection of the patient. It is thus possible to decrease the quantity of immunosuppressants generally used in the transplantation of tissues in the conventional technique. The risk of side effects owing to the use of immunosuppressants is thus greatly reduced. Of course there is no problem of immunorejection if the cells of the patient himself are used in the gene therapy because such therapy is a self-transplantation.
5) Simple operation without the need of the patient""s hospitalization is safe and free from the risk incurred in conventional treatment. Because this is a transplantation to the skin, the condition of transplantation is visible externally at all times. The transplanted artificial skin can be removed when necessary.
Various biologically active substance-producing cells can be used in the present invention for incorporating expression vector with gene therefor in the cells. For example, insulin-producing cells can be prepared by transfecting placmid vector pBMG-neo-ins possessing cDNA of insulin and neomycin resistance gene (selection marker) to animal cells using a known method. Another method is to transfect plasmid vector pRIS-proins-Ifur-IIfur-B10D into animal cells. This plasmid vector contains mutant insulin gene that convert proinsulin expressed from the gene into insulin by the action of furin and by the substitution of the 10th amino acid in the insulin chain B.
The gel to accommodate the biologically active substance-producing cells may be prepared from, for example, collagen, fibrin, agarose, etc. by using known methods. For example, the hybrid gel containing cells with insulin genes therein may be prepared and used as artificial skin for curing diabetics in the following manner:
(1) Pieces of skin of an experimental animal are collected. Epidermal cells and fibroblasts, two major constituent cells of skin, are separated from the skin samples and cultured.
(2) Expression vector containing insulin gene is transduced into these cells to derive insulin-secreting cell lines.
(3) Hybrid type artificial skin with the insulin-secreting function is constructed from these cell lines using collagen gels, etc.
(4) The insulin-secreting hybrid type artificial skin is transplanted.
To be more specific, the hybrid gel secreting biologically active substance of the present invention can be manufactured in accordance with the method of Asaga et al (H. Asaga et al, Experimental Cell Research, 193: 167, 1991) as follows:
Quadruple concentrated medium of cell culture, serum, purified water, and, for example, collagen (0.5% solution) are mixed in the ratio of 2.5:1:2.5:4 according to the required quantity while cooling the mixture with ice. An aqueous solution of 1N sodium hydroxide is mixed dropwise into the mixture to adjust to pH 7.4. The mixture is separately injected into hydrophobic plastic laboratory dishes of 35 mm in diameter, 2 ml in each dish. The dishes are immediately transferred to a 37xc2x0 C. thermostat. The collagen solidifies in several minutes to produce gel. Biologically active substance-producing cells are mixed into the above mixture just before collagen solidifies in order to enclose the cells in the gel.
To allow meshy material or porous membrane to coexist in the gel, one needs only to mix these in the above solution together with the biologically active substance-producing cells.
Commercially available culture solutions, serum and collagen can be used in the present invention.
It is effective to give an appropriate strength to the collagen gels to facilitate transplantation of the product to the skin. An appropriate strength can be given to the gel by, for example, mixing an appropriate number of skin-derived fibroblasts according to the method of Bell et al (E. Bell et al, Proceedings of the National Academy of Sciences, 76(3): 1274, 1979). An appropriate strength can be given to the gel as a result of contraction of the gel owing to the fibroblasts. Skin-derived fibroblasts can be obtained, for example, by culturing a small portion of skin collected from the patient according to the primary explant technique (R. I. Freshrey, Culture of Animal Cells, Alan R. Liss, Inc., New York, 1987).
It is also effective to make the gel surface active to ensure good attachment to the skin by overlaying by culture skin-derived epidermal cells on the gel before they are transplanted to the skin.
Skin-derived epidermal cells to be overlaid on the gel may be obtained by culturing epidermal cells obtained from the skin of the patient himself in the same way as described for the fibroblasts using the method of, for example, Green et al (H. Green et al, Proceedings of the National Academy of Sciences 76: 5665, 1979).
It goes without saying that the present invention is effective also when the gel is transplanted subcutaneously without overlaying epidermal cells.
Practically, many forms are of the invention available.

Biologically active substance-secreting hybrid gel

Research Development Corporation of Japan


A fixing apparatus, for fixing a toner on a recording material by using Joule heat which is generated by applying a voltage across the conductors or across the electrodes to supply a current mostly to a fixing portion, (I) comprises a heating device having a first conductive layer, a pressure-sensitive conductive resin layer which is formed on the first conductive layer, and a second conductive layer formed on the pressure-sensitive conductive resin layer, (II) comprises a heating device having a first conductor and a fixing sheet substantially made of a pressure-sensitive conductive resin layer and a second conductive layer, or (III) comprises a heating device having a fixing sheet made of a heat-generating resistor and first and second electrodes insulated from each other.

1. Field of the Invention
The present invention relates to a fixing apparatus of electrophotographic recording in which the power required for fixing is reduced.
2. Description of the Related Art
An electrophotographic recording apparatus has features such that it produces less noise as it is a non-impact recording apparatus, it can record characters clearly, its recording speed is high, and its running cost is relatively low. Therefore, it is recently used as an output terminal of OA equipment. The market of the electrophotographic recording apparatus is also quickly widening.
FIG. 1 is a schematic diagram of a recording apparatus of a laser printer as an example of the electrophotographic recording apparatus. The outline of the electrophotographic recording apparatus will be described. A conventional electrophotographic recording apparatus uses a photosensitive drum 100, as shown in FIG. 1. The entire surface of the photosensitive drum 100 is first uniformly charged to, e.g., about -700 V with negative charges by a charging apparatus 101 comprising a corona charger. Then, the photosensitive drum 100 is irradiated with a laser beam 102 in accordance with an image signal. The resistance of a portion of a photosensitive material which is irradiated with the beam is decreased. Therefore, an electrostatic latent image in which the negative charges are erased is formed at the portion irradiated with the laser beam 102. Usually, one semiconductor laser is used as the laser, and the beam modulated in accordance with the image performs scanning by a rotating polygonal mirror.
The electrostatic latent image formed in this manner is then developed by a developing apparatus 103. That is, when a developing bias of about -500 V is applied to the developing roller, a toner as fine color particles charged with, e.g., negative charges by reversal development attaches to the portion of the electrostatic latent image on the photosensitive drum 100 in which the negative charges are erased, thereby visualizing the latent image. Then, recording paper 105 which is picked up by paper feed rollers 104 from a paper cassette (not shown) is conveyed in synchronism with an image signal, and contacts the photosensitive drum 100. Transfer of the visualized toner image to the recording paper 105 is performed. In a transfer charger 106, positive charges are applied to, e.g., the lower surface of the recording paper 105. Thus, the negatively charged toner image on the photosensitive drum 100 is attracted to the recording paper 105 and transferred to it. The image-transferred recording paper 105 is then separated from the photosensitive drum 100 by a separation charger 107.
Finally, the toner is heated and pressed by a fixing apparatus 111 having a heat roller 110 and fixed on the recording paper 105, thereby completing recording. Note that part of the toner which is not transferred to the recording paper 105 remains on the photosensitive drum 100. The remaining toner on the drum 100 is cleaned by being scraped by a cleaner having a cleaning blade 108. Thereafter, the entire surface of the drum 100 is exposed to light by an erasure lamp 109 comprising an LED or the like, thereby erasing the charges on the photosensitive drum 100.
In this manner, in the electrophotographic recording apparatus, the steps of charging, formation of a latent image, development, transfer, and fixing are performed to form an image. The drum is cleaned in the cleaning step and is repeatedly used. Processes may differ more or less depending on the types of apparatuses but basically include the above steps.
The laser printer has been briefly described as a typical example of the electrophotographic recording apparatus. As the electrophotographic recording apparatus, not only a laser printer but also a recording head which uses other light-emitting elements for writing an electrostatic latent image have been developed and marketed. In the laser printer, a beam generated by one laser is radiated onto a polygonal mirror which rotates mechanically at a high speed or a hologram to scan the dots. A solid state scanning method which uses an array light source in view of reduction in system size and cost also currently has begun to attract attention. For example, an electrophotographic recording apparatus with a head in which light-emitting elements, e.g., LEDs, liquid crystal shutters, EL elements, plasma light-emitting elements, and fluovescent dot array, or light-shutter elements are arranged in an array has been put into practical use. Either electrophotographic recording apparatus described above is generally called an optical printer and utilized as an output apparatus, e.g., a printer or a digital copying machine. Another example of the electrophotographic recording apparatus is an analog copying machine in which the original is irradiated with light from, e.g., a conventionally used fluorescent lamp, and the light reflected by the original is guided to the photosensitive member to form an electrostatic latent image, thereby copying the original. Furthermore, another recording method called ion flow recording or ion deposition recording is also available. According to this method, a dielectric material is used in place of a photosensitive member. Ions are blown from pores formed in an array manner. An electrostatic latent image is formed on the dielectric material by the ions.
As has been described above, since the electrophotographic recording apparatuses have excellent features, they are often utilized recently as output terminal apparatuses of OA equipment. Various methods for them are developed and put into practical use, with their market rapidly expanding.
In these electrophotographic recording apparatuses, recording is performed in the common steps of charging, formation of a latent image, development, transfer, and fixing, as described above. One of the characteristic features of the electrophotographic recording apparatus is that a very low energy is required for forming an electrostatic latent image. For example, to form a latent image of one dot, a light energy of as small as about 10.sup.-6 to 10.sup.-5 J/cm.sup.2 is applied to the photosensitive member. In contrast to this, to form one dot on a recording material by, e.g., a thermal transfer recording apparatus, a large recording energy of about 2 to 6 J/cm.sup.2 is required. If only these facts are considered, an electrophotographic recording apparatus seems to have a very high efficiency and its power consumption seems to be very low compared to those of a thermal transfer recording apparatus.
In an actual electrophotographic recording apparatus, however, the power consumption is normally about 1.5 Kw in an apparatus which can record 8 to 12 sheets per minute, and is about 500 to 600 W at minimum in a low-speed apparatus which can record 4 sheets per minute. These values are of the same level or higher when compared with a thermal transfer recording apparatus. In the electrophotographic recording apparatus, some of the recording processes from charging to transfer of a toner image on plain paper are certainly realized with a very low energy. However, a high energy is consumed in the final step of fixing the toner to the recording material. Therefore, the power consumption as a whole in the electrophotographic recording apparatus is increased. For example, the fixing energy is as large as about several tens of J/cm.sup.2, which is about ten times the recording energy of the thermal transfer recording apparatus.
Most electrophotographic recording apparatuses use a heat roll type fixing apparatus which performs fixing by heat and pressure. The fixing apparatus which uses a heat roll is safe as it is free from a danger such as ignition. Since the heat capacity is large, stable image quality can always be obtained. The fixing intensity is sufficiently higher than that of pressure fixing and the like.
However, since the heat roll has a large heat capacity, it takes time to increase the temperature of the heat rolls to a value required for fixing. Therefore, the apparatus cannot be used immediately after turning on the switch, and a warm-up time of about several minutes is usually necessary. Since the heat roll has a large heat capacity, a heater having high power consumption is needed, and thus, e.g., an infrared lamp of about 500 to 1,000 W is normally incorporated in the roller. In fine, the conventional electrophotographic recording apparatus uses a heat roll having a large heat capacity as the fixing apparatus. Therefore, although it has several advantages, it also has disadvantages in that high power consumption is needed and the warm-up time is long. When size reduction of the electrophotographic printing apparatus is considered, it is not preferable to use, as the fixing apparatus, a heat roll which has high power consumption and generates much heat.


A method for fabricating a semiconductor device comprises the steps of forming a depression on a substrate, bonding a plate of a single crystal semiconductor material on the substrate to establish a contact such that a closed space is formed in the substrate in correspondence to the depression, reducing the thickness of the plate, forming a penetrating opening through the plate in communication to the space to form a bridging part in the plate as a region left from the formation of the penetrating opening, forming an insulation film to cover at least a lower major surface and both side walls of the bridging part, filling the space by depositing polysilicon through the penetrating opening, providing a conductivity to the polysilicon that fills the space, removing the polysilicon that has been deposited on the upper surface of the bridging part to expose a crystal surface of the semiconductor material forming the plate, and forming an active device on the bridging part.

The present invention generally relates to semiconductor devices, and more particularly to an SOI (silicon-on-insulator) device that is suitable for integration on a common substrate with improved breakdown voltage.
The use of so-called SOI devices is expanding particularly for devices that are required to have a high breakdown voltage. For example, the SOI devices are used commonly for display drivers. Further, a SOI devices are suited for use in the radiation environment. Even in the applications of SOI devices, there is a persisting demand to increase the operational speed of the device.
Generally, the SOI devices are formed on a layered semiconductor body that includes a silicon substrate, a silicon oxide insulation formed on the substrate and an active layer that is formed on the silicon oxide insulation layer. Such a structure can be formed by bonding a single crystal silicon layer, acting as the active layer on the oxide insulation that in turn is formed on the silicon substrate, at a high temperature. Particularly, when the thickness of the silicon oxide insulation layer is reduced, the device shows various advantageous features such as the elimination of so-called short channel effect, the improvement of output current, and the like. Thus, efforts are made to reduce the thickness of the silicon oxide insulation layer.
In such SOI devices, however, there is a tendency that a punch-through current flows from the source to the drain, particularly when the thickness of the silicon oxide insulation layer is thin and a large drain voltage is applied. This is believed to be caused by the potential of the silicon substrate that is located under the silicon oxide insulation layer. Because of the reduced thickness of the silicon oxide insulation layer, the potential of the silicon substrate acts as the gate voltage and the current flows unwantedly from the source to the drain along the bottom surface of the active layer. In order to eliminate this so-called backchannel effect, application of a bias voltage to the substrate is proposed to eliminate the conduction along the bottom surface of the silicon active layer.
Referring to FIG. 1 showing a typical SOI device 10, the device 10 comprises an n-channel MOS transistor formed on a silicon active layer 11 that in turn is formed on a silicon oxide insulation 12, and the silicon oxide insulation 12 is formed on a silicon substrate 13. Further, the silicon substrate 13 is applied with a bias voltage V.sub.bias such that no punch-through current flows from a source 11a to the drain 11b along the channel formed along the insulation layer 12.
In the n-channel MOS transistor, a positive voltage is used as the bias voltage V.sub.bias. This conventional construction, however, has an obvious problem of inapplicability to the CMOS devices wherein n-channel MOS transistors and p-channel MOS transistors are formed on a common substrate. In order to achieve this, one requires a complex structure and hence a complex process.
Further, such a conventional SOI device has suffered from a problem of leakage current flowing along the silicon oxide layer 12. It should be noted that the silicon oxide layer 12 is exposed to the environment for a long time after it is formed on the surface of the silicon substrate 13. Thereby, there is a tendency of the silicon oxide layer collect impurities on the surface thereof, and such impurities degrade the quality of the interface between the silicon oxide layer 12 and the silicon layer 11 formed thereon.

SOI device and a fabrication process thereof


Brain waves are used as a biometric parameter to provide for authentication and identification of personnel. The brain waves are sampled using EEG equipment and are processed using phase-space distribution functions to compare digital signature data from enrollment of authorized individuals to data taken from a test subject to determine if the data from the test subject matches the signature data to a degree to support positive identification.

The field of the invention is identification of persons using biometric parameters.
A biometric parameter of humans is needed to positively identify trusted persons. The typical biometric features include body odor, body salinity, ear pattern, facial recognition, fingernail bed, fingerprints, hand geometry, hand grip, infrared fingertip image, keystroke dynamics, hand vasculature, eye iris and retina, (walking) gait, written signature, voice, and facial thermogram. The attributes of a biometric identity parameter are: security of the factor, protection of individual privacy, compliance with government standards for reliability and accuracy, and adaptability to regional, state, and local requirements. The objectives of personal identification are to deter identity deception and to accelerate recognition of trusted personnel (e.g., authorized firearm carriers in air travel, state/regional/local officials, and trusted insiders in critical infrastructure areas). Other biometric features include: universality—how commonly the biometric is found in each person; uniqueness—how accurately the biometric distinguishes one person from the other; permanence—how well the biometric resists the effects of aging; collectability—how easily the biometric is acquired for processing; performance—achievable accuracy, speed and robustness of the biometric; acceptability—public acceptance of the technology in their daily lives; circumvention—difficulty to circumvent or fool the system into accepting an impostor.
Authentication should require that the subject person be screened in a live setting, as opposed to reviewing records that can be forged, or reviewing passive biometric identifiers that can be extracted from someone who is uncooperative, unaware, or even deceased.

Methods for using a biometric parameter in the identification of persons


A segmented target system and method performs an ionized physical-vapor deposition of a material on a work piece. The system includes an optimal permanent magnet array, vacuum plate, and multiple target segments formed from an electrically conductive material and are coupled to the vacuum plate. The system further includes multiple power sources where each power source couples to at least one of the target segments and where each of the power sources couples to at least one phase shifter forming a multiple inductive source. A circuit couples the power sources and the target to transfer power from the power sources to the target. The interaction of the multiple inductive sources once powered forms an inductively coupled electromagnetic field approximately parallel to the target that increases the ionization of the PVD sputter species, enhances the material density and collimation of deposition on the work piece.

The present invention relates to a method and system for plasma-assisted processing of micro-electronic devices and, more particularly, to a system and method using a segmented-target cathode for performing ionized physical-vapor deposition processes, such as those that are utilized to produce semiconductor data storage, flat-panel display, photovoltaic and other devices used in electronic and information systems.
Plasma-assisted physical-vapor deposition (PVD) using various sputtering target materials is commonly used in thin-film fabrication technology for manufacturing of semiconductor, data storage, flat-panel display, and photovoltaic devices. Plasma sputtering is the most important and widely used thin-film deposition fabrication technique. In semiconductor integrated circuit (IC) manufacturing, PVD processes are used to deposit contact/via barrier (e.g., TiN or TaN) and glue (e.g., Ti) layers as well as metallization materials (e.g., Al or Cu). State-of-the-art semiconductor technologies for producing high-performance logic devices such as microprocessor chips employ four to six levels of metal interconnects. Current salicided CMOS technologies with four levels of interconnects may use (a) one PVD step (e.g., Ti deposition) to form self-aligned silicide (i.e., salicide), (b) two PVD steps to deposit Ti and TiN layers at the contact level, (c) one PVD step to deposit the first level of interconnect (typically Al, plus 1% Si, and 0.5% Cu), (d) one PVD step to deposit an anti-reflection coating (ARC) layer to facilitate the interconnect patterning process, and (e) up to nine additional PVD process steps to form the three additional interconnect levels and associated via liner and barrier layers, as well as ARC layers. This process description illustrates that advanced semiconductor IC manufacturing technologies with multiple levels of interconnect can often require numerous PVD process steps, some with stringent step coverage and bottom coverage requirements in order to produce continuous coverage over high-aspect ratio contact and via structures.
The performance, reliability, and yield of the multilevel interconnects strongly influence the reliability and manufacturing yield of semiconductor chips, such as high-performance microprocessors. As a result, PVD fabrication processes play a significant role in semiconductor integrated circuits, since they influence all significant multilevel interconnect performance and reliability parameters.
Existing commercial PVD technologies usually employ DC or RF or pulsed DC (AC) magnetron sputtering in vacuum processing chambers. A typical commercial PVD module includes a single-substrate (single-wafer) vacuum process chamber (preferably designed as a cluster tool module), a temperature-controlled (with an option to apply biased electrical power) chuck to hold the substrate, and a sputter target (or magnetron cathode) that contains the desired material. DC (or pulsed DC) magnetron plasma excitation (with DC power levels up to 20 kW and higher) is usually used for sputter deposition of electrically conductive materials such as Al, Ti, Co and TiN. RF magnetron (or pulsed DC) sputtering is usually used for sputter deposition of electrically insulating (or resistive) materials. RF diode sputtering (as opposed to magnetron PVD sputtering) is the preferred choice for sputter deposition of some magnetic and insulating materials for applications such as thin-film head fabrication.
Each of these PVD methods generates a plasma from an inert plasma gas an sustains the plasma near the target area. The target material atoms or molecules are then sputtered from the target surface and a fraction of them is deposited on the device substrate. Sputter etching of the target surface occurs due to energetic argon ion or another suitable ionized gas (such as xenon) species. During the sputtering process, the sputtered species (mostly neutrals) are emitted within the vacuum chamber plasma environment over a wide range of spatial angles and a portion of the sputtered flux deposits on the device substrate. Other sputtering processes, such as reactive sputtering processes, use nitrogen or oxygen or another reactive gas, instead of, or in addition to, an inert gas within the vacuum processing chamber. Reactive magnetron sputtering processes that, deposit TiN layers from elemental Ti targets illustrate an example of this technique.
In general, the flux of the sputter atoms or species that the PVD target material emits has a relatively broad angular distribution. Similarly, the sputter flux of species arriving at the substrate surface has a relatively broad spatial distribution angle. This broad spatial distribution angle does not usually present a problem in applications involving substrates without high-aspect-ratio features.
However, some semiconductor device manufacturing applications involve substrates with high-aspect-ratio features. These applications require some degree of spatial filtering or collimation for the sputter species. A broad angular distribution of the PVD flux implies poor collimation or a low degree of collimation, whereas a narrow angular distribution relative to the perpendicular axis indicates a higher degree of PVD collimation. For instance, semiconductor interconnect applications require collimated sputtering for deposition of the contact and via liner/glue and barrier layers (e.g. Ti/TiN) when using high-aspect-ratio (e.g., on the order of xe2x89xa73:1) contacts and vias due to the bottom and sidewall coverage requirements. For a contact/via hole of width (or diameter) W and height H, the following parameters can be defined:                               A          .          R          .                                  xe2x80x83                                  =          Δ                                              H            W                                          xe2x80x83                                          (                          aspect                                            xe2x80x83                                          ratio                        )                                                            Bottom                                xe2x80x83                              Coverage                                  =          Δ                                              t            b                    d                                                  Sidewall                                xe2x80x83                              Coverage                                  =          Δ                                                            t              s                        d                                          xe2x80x83                                          (                          step                                            xe2x80x83                                          coverage                        )
where d is the thickness of sputtered material layer on extended flat top surfaces, tb is the sputtered material thickness at the bottom of the hole, and ts is the thickness of the sputtered material on the hole sidewall at mid height.
In conventional PVD processes without any built-in sputtering-collimation feature, the bottom coverage and sidewall coverage of the sputter deposited material degrades significantly as the microstructure aspect ratio increases. This degradation becomes increasingly worse for microstructure aspect ratios of greater than xcx9c3:1. As a result, for applications requiring good (e.g., xe2x89xa725%) bottom coverage and sidewall coverage (e.g., xe2x89xa750%), existing PVD technologies use a collimator plate placed between the PVD target or cathode assembly and the substrate inside the vacuum chamber.
The collimator plate, usually made of aluminum or titanium, consists of an array of circular or hexagonal closely packed holes that typically have an aspect ratio of 1:1 or higher. The collimator plate operates as a spatial filter to reduce the angular distribution of the sputter flux species arriving at the substrate. The degree of collimation increases (thus decreasing the angular distribution of the sputter flux species at the substrate) as the collimator plate hole aspect ratio increases. Although physical collimation via a fixed collimator plate is extensively practiced in commercial PVD processes for semiconductor contact/via glue/liner and barrier deposition, it has a number of disadvantages.
First of all, a trade off exists between the sputter deposition rate (throughput) and the degree of collimation. In other words, higher degrees of collimation require collimators with higher aspect ratios resulting in a reduced deposition rate on the substrate. This trade-off in physically collimated PVD systems presents a significant throughput limitation. Secondly, the collimator becomes gradually coated with the sputtering material. This can result in particulate generation within the PVD vacuum chamber. Moreover, the coating creates a non-uniform blockage of the collimator holes that can result in long-term drift of the process uniformity. These problems lead to frequent removal and cleaning of the collimator plate. The need for frequent cleaning and maintenance of the collimator has a negative impact on the overall process uptime and product throughput. Finally, a fixed collimator plate does not allow for variable (i.e., adjustable in real-time) and controlled degrees of collimation, since the degree of collimation is fixed by the aspect ratio of the collimator. Some processes require multi-step depositions with and without PVD collimation in order to maximize the process throughput while, at the same time, establishing optimal hole or trench filling capability. These processes must use multiple PVD chambers (including PVD chambers or modules with collimation and those without collimation) on a cluster tool which results in an increased cost-of-ownership.
Another prior art PVD collimation method is the so-called xe2x80x9cnatural collimationxe2x80x9d or xe2x80x9clong-throughxe2x80x9d collimation method. The natural collimation method relies on providing a relatively large spacing (as compared to substrate diameter) between the target and the substrate in a low-pressure (e.g., below 1 m torr) process ambient. In this collimation technique, higher collimation ratios require larger target-to-substrate spacing values and significantly reduced PVD pressures. Like the physical collimation method with a collimator plate, the natural collimation technique also suffers from a trade-off between the degree of collimation and the deposition rate. Moreover, a higher collimation ratio in a natural collimation method results in a higher PVD chamber volume and demands reduced processing pressures to reduce scattering, requiring a higher pumping speed pump package.
Thus, there is a need for an ultraclean PVD collimation technique which does not generate particulates and does not require regular and frequent replacement or cleaning of the PVD chamber components.
Moreover, there is a need for an improved PVD collimation that does not suffer from a trade-off between the deposition rate and the degree of PVD collimation.
There is also a need for an improved collimation technique which provides a capability for adjustable and controlled collimation (programmable electrical collimation) of the PVD process in real time. The collimation control capability will be established via a controlled and adjustable electrical parameter (substrate bias, ionization source RF power, or both of these parameters) with or without a capability to adjust the target-to-substrate spacing.
There is also a need for a PVD technology that can perform high-throughput processing of substrate using high rate deposition with enhanced processing capability without requiring higher PVD chamber volume.
There is also a need for a PVD technology that can deposit material layers with excellent thickness control and process control capability for a wide range of material layer thicknesses from very thin (e.g., down to 10xc3x85) to relatively thick layers.
The present invention provides an apparatus and method for processing a semiconductor device using a segmented target assembly in a physical-vapor deposition (PVD) process module that substantially eliminates or reduces disadvantages and problems associated with previously developed techniques for performing PVD processes.
More specifically, the present invention provides a segmented target system and method for performing ionized physical-vapor deposition of a material on a work piece. The segmented target system includes a permanent magnet array (or electromagnets), a vacuum plate, and a target having a plurality of target segments formed from an electrically conductive material. The plurality of target segments are coupled to the vacuum plate. The system further includes a plurality of power sources (or a single power source with a plurality of distribution branches) where each power source or distribution branch couples to at least one of the target segments and where each of the power sources (or distribution branches) couples to at least one phase shifter to form a plurality of inductive sources when power is applied. A circuit couples to both the power sources and the target to transfer power from the power sources to the target. Upon powering the power sources, the interaction of the plurality of inductive source forms an inductively coupled magnetic field approximately parallel to the target that increases the ionization of the PVD sputter species and enhances the material density and uniformity of deposition on the work piece.
The present invention provides an important technical advantage by providing an improved PVD collimation that does not suffer from a serious trade-off between the deposition rate and the degree of PVD collimation.
Another technical advantage of the present invention is that it provides an ultraclean PVD process technique that eliminates or greatly reduces particulate generation due to collimation and does not require regular and frequent replacement or cleaning of a physical collimator (due to lack of a need for a physical collimator).
The present invention provides another technical advantage by providing the capability to adjust and control the degree of collimation (programmable electrical collimation) of the PVD process in real time. The present invention can implement variable collimation via a controlled and adjustable electrical parameter (substrate bias, ionization source RF power, or both of these parameters).
The present invention provides another technical advantage by performing high throughput processing of substrate using high-rate deposition with enhanced processing capability that does not require an increased volume PVD chamber.
A further technical advantage of the present invention is the capability to provide a highly repeatable PVD process for deposition of ultrathin (e.g., down to 5-20xc3x85) layers by ICP-assisted generation of a stable plasma, allowing the use of very low or reduced electrical power levels on the PVD cathode.

Segmented-target ionized physical-vapor deposition apparatus and method of operation