A concentrate of binder at the tufts produces a lighter and more flexible carpet, which allows for direct attachment of hook-and-loop means on the carpet backing. Thermoplastic binder yarns are pinned by the pile yarns against the primary backing. Subsequent application of heat melts the binder yarns and fuses the tufts and primary backing together. An alternate embodiment uses highly shrinkable binder sheet placed over the backing before tufting, instead of the binder yarns.

1. Field of the Invention
The present invention relates to a tufted pile surface structure and to a method for producing the same in which binder material is concentrated beneath the backstitch portions of the pile yarns.
2. Description of the Prior Art
In the manufacture of a tufted pile surface structure each of a plurality of pile yarns is drawn by a tufting needle through a backing to form face fiber elements and backstitch elements. The face fiber elements lie adjacent to the upper face of the backing while the backstitch elements are disposed along the lower face of the backing. Presently, the backstitch elements are secured by a thermoset or thermoplastic binder placed on the lower face of the backing. In actuality, only a small portion of the binder material serves to hold the backstitch elements in place, while a large portion of the binder material is wasted. Using very large quantities of binder to achieve deeper penetration of the binder through the backing to improve pull-out or unraveling resistance increases binder wastage, stiffens the carpet, and increases carpet weight.
Accordingly, it is believed advantageous to provide a method of manufacture of a tufted pile surface structure that concentrates binder material beneath the backstitch elements to produce a lighter and more flexible carpet structure. Such a structure will also allow the direct deployment xe2x80x9chook-loopxe2x80x9d attachment members on the back of the carpet.
The present invention is directed to a pile surface structure and a process for manufacturing the same Each of a plurality of pile yarns is tufted by a separate tufting needle through a plurality of needle insertion points in the backing to form face fiber elements that lie adjacent to the upper face of the backing and backstitch elements that overlay the lower face of the backing. The insertion points produced by the tufting needles form a pattern of parallel lines that extend longitudinally and transversely along the back face of the backing.
An activated binder material is disposed beneath the backstitch elements to hold the backstitch elements to the backing. The activated binder material is concentrated along the longitudinal and/or the transverse lines of insertion points, with the lower face of the backing member between the adjacent lines of insertion points being left substantially free of binder.
In accordance with this invention the binder material is applied before tufting. The binder material may take the form of either a sheet or a plurality of longitudinally laid strands of binder material that when activated, form stripes of binder extending along the lower face of the backing member. During tufting each needle passes through the binder material so that binder is disposed between the backstitch elements and the lower face of the backing.

Tufted pile structure having binder concentrated beneath the backstitches


A first PSG film having a control hole is formed on a silicon substrate formed having a circuit, and a first aluminum alloy line layer resistive to stress migration made of Al-Si alloy is formed on the first PSG film, so as to electrically contact, via the contact hole, the surface of a semiconductor substrate. The alloy line layer is formed by use of a sputtering method, and the crystal face is oriented, mainly in the (111) plane, by controlling the substrate temperature at the time of sputtering, as well as the Ar gas pressure, the alloy depositing rate, and the degree of vacuum prior to the commencement of alloy depositing. The grain size l of the alloy crystal is set so as to satisfy "(W/14)<l<W" with respect to the width W of the line formed by etching, and preferably to also satisfy "(W/4)<l<(W/1.5)".

The present invention relates to aluminum alloy line formed in an LSI and, more particularly, to an improved aluminum alloy line formed by microminiaturization, having a small number of defects (referred to hereinafter as "Al void").
The achieving of high integration in semiconductor integrated circuits has recently become highly desirable. High integration requires the use of specialized techniques for microminiaturization and multi-metal-layer lamination in a line structure. Microminiaturization of the line structure necessitates the design of an aluminum alloy line of much narrower width than has previously been attained. When the width of the aluminum alloy line is reduced to as small as 2 to 3 microns or less, Al voids tend to occur in the line.
Since the multi-metal-layer line structure is made of various thin films such as thin insulator films and thin aluminum alloy films, stress is imposed on the internal structure of a semiconductor device including the multi-metal-layer line, which causes Al voids to be produced in the aluminum alloy line. A semiconductor integrated circuit having large Al voids is not reliable. For example, Al voids cause the line to burn out or become disconnected, or cause a reduction of its sectional area, resulting in an increase in the electrical resistance of the layer. An increase in the electrical resistance causes increased heat generation which causes the line to become disconnected and thus, the operating speed of the circuit is reduced. The increase in the electrical resistance of the line may cause electromigration when a large current flows in the line.
By means of a model test, it has been found that Al voids are formed in the following way. When tensile stress is applied from a passivation film to the aluminum alloy line, it is concentratedly applied at the crystal grain boundaries of the line. In order to alleviate this concentrated stress, the aluminum atoms moves from the grain boundaries, inevitably forming Al voids. This phenomenon is known as stress migration. Hence, in order to suppress such movement of aluminum atoms, thereby to avoid Al voids, copper, which can readily precipitate in the grain boundaries an in Al-Si allow line, has been added to the allow, thus providing an Al-Si-Cu alloy line. In the Al-Si-Cu alloy line, the copper acts as an obstacle to the movement of the aluminum atoms, thus suppressing the formations of Al voids.
However, while the Al-Si-Cu alloy line can suppress the forming of Al voids to a certain degree, it cannot, however, reduce the void coefficient ratio lv of the alloy line below 30%-40%.
Here, the void coefficient ratio lv is the value represented by the following equation: EQU lv=d/W
where W is the width of aluminum alloy line 50, and d is the maximum void width in FIG. 11. The smaller the void coefficient ratio lv the more the occurrence of voids is suppressed.

Aluminum alloy line resistive to stress migration formed in semiconductor integrated circuit


An error signal detection apparatus for an optical recording/reproducing system including a light source emitting a light beam and an objective lens focusing the light beam to form a light spot on a recording medium, the apparatus including: a photodetecting unit dividing at least a part of the light beam passed through the objective lens after being reflected/diffracted from an information stream of the recording medium into light beam portions, and detecting the light beam portions; and a signal processor detecting phase differences between detection signals from the light beam portions to detect a tangential error signal, a defocus error signal, and/or a radial tilt error signal.

This application claims the benefit of Korean Application No. 2000-68501, filed Nov. 17, 2000, in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an error signal detection apparatus for an optical recording/reproducing system, and more particularly, to an error signal detection apparatus for an optical recording/reproducing system, which can detect a tangential tilt error signal and/or a radial tilt error signal with respect to a relative tilt between an objective lens and a recording medium, and/or a defocus error signal, using a main light beam used for recording an information signal on or reproducing an information signal from the recording medium.
2. Description of the Related Art
Optical pickups record an information signal on or reproduce the information signal from a recording medium, such as an optical disc seated on a turntable and rotating, while scanning the recording medium in the radial direction. However, if the rotating optical disc is tilted with respect to the optical axis, due to bending of the optical disc itself or due to an error in loading the disc, degradation of a recording/reproduction signal could occur.
When an optical pickup adopts a light source, which emits a shorter wavelength of light and an objective lens having a high numerical aperture (NA) to increase recording density, comma aberration caused by a tilt of the optical disc increases, thereby further degrading the recording/reproduction signal. Comma aberration increases as the tilt of the optical disc increases because optical aberration is proportional to xcex/(NA)3.
In an optical recording/reproducing system for high-density recording and reproduction in a recording medium, such as a digital versatile disc (DVD) and/or next generation DVD series (so-called high definition (HD)-DVD), there is a need for a tilt error signal detection apparatus for correcting a record/reproduction signal according to a relative tilt between the recording medium and the objective lens.
To accurately detect a radial tilt error signal, there is a need for the tilt error signal detection apparatus in the optical recording/reproducing system to detect a radial tilt error signal without being influenced by a tangential tilt, a defocus, or a detrack. To accurately detect a tangential tilt error signal, there is a need for the tilt error signal detection apparatus for in the optical recording/reproduction system to detect a tangential tilt error signal without being affected by the radial tilt, the defocus, or the detrack.
On the other hand, as shown in FIG. 1, a light beam reflected by a recording medium 10, after being focused as a light spot on the recording medium 10, is diffracted into a 0th order diffracted beam and xc2x11st order diffracted beams by, for example, pits (P) formed on the recording medium 10. Thus, a photodetector 9 in the optical pickup to detect an information signal receives the 0th order diffracted beam and the xc2x11st order diffracted beams. For the 0th order diffracted beam and xc2x11st order diffracted beams received by the photodetector 9, the 0th order diffracted beam overlaps each of the xc2x11st order diffracted beams that do not overlap each other. Detection signals from the overlapping portions between the 0th order diffracted beam and each of the xc2x11st order diffracted beams, and a detection signal from a pure 0th order diffracted beam have different phase characteristics. That is, the phase characteristics of individual light beam portions reflected/diffracted by the recording medium 10 differ from one to another. The phase characteristics of the detection signals vary according to a degree of tangential and/or radial tilt.
In a conventional error signal detection apparatus for detecting a tangential or radial tilt, a light beam reflected by the recording medium 10 is received as four divided light beams by the photodetector 9, which is divided into four sections. The four divided light beams are photoelectrically converted, separately, and the detection signals from the four divided light beams are summed or subtracted to detect a tangential or radial tilt error signal. Thus, the original phase characteristic according to position in the light beam, which is reflected/diffracted from the recording medium 10, cannot be reflected sufficiently in detecting a tangential or radial tilt error signal. As a result, the tangential or radial tilt error signal cannot be accurately detected.
On the other hand, when defocus occurs in recording data in the next generation DVD series recording medium for high-density recording, a method for compensating for defocus is needed because the high-density recording medium is greatly affected by the defocus compared to a conventional recording medium, which uses a red laser beam. In other words, when a short-wavelength light source, for example, having a blue wavelength of 420 nm or less, and an objective lens having an NA of 0.6 or more are used for high-density recording, a defocus margin becomes smaller due to a small focus depth of an incident light beam. As a result, even if a small degree of defocus occurs in the recording data, the problem of the defocus can be serious for the high-density recording medium.
As well known, when recording is performed on the DVD series recording medium, defocus may be controlled with a variation of about 230 nm by using a 650-nm light beam and an objective lens having an NA of 0.6. However, when recording is performed on the next generation DVD series recording medium using a blue light and an objective lens having, for example, an NA of 0.85, there is a need to accurately control the defocus to be within the range of tens of nanometers.
To precisely control the defocus to be within the range of tens of nanometers for data recording on the next generation DVD series recording medium, there is a need to detect a defocus error signal without being affected by detrack, and a relative tangential and radial tilt between the objective lens and the recording medium.
Various objects and advantages of the invention will be set forth in part in the description that follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
To solve the above and other problems, it is an object of the present invention to provide an error signal detection apparatus for an optical recording/reproducing system, which can accurately detect a tangential tilt error signal in consideration of phase characteristics of light beam portions reflected/diffracted from an information stream of a recording medium, without being affected by radial tilt, defocus, and detrack.
It is another object of the present invention to provide an error signal detection apparatus for an optical recording/reproducing system, which can accurately detect a radial tilt error signal in consideration of phase characteristics of light beam portions reflected/diffracted from an information stream of a recording medium, without being affected by tangential tilt, defocus, and detrack.
It is another object of the present invention to provide an error signal detection apparatus for an optical recording/reproducing system, which can accurately detect a defocus error signal in consideration of phase characteristics of light beam portions reflected/diffracted from an information stream of a recording medium, without being affected by tangential and radial tilt, and detrack.
To achieve these and other objects of the present invention, there is provided an error signal detection apparatus for an optical recording/reproducing system including a light source emitting a light beam and an objective lens focusing the light beam to form a light spot on a recording medium, the apparatus including: a photodetecting unit dividing at least a part of the light beam passed through the objective lens after being reflected/diffracted from an information stream of the recording medium into light beam portions, and detecting the light beam portions; and a signal processor detecting phase differences between detection signals from the light beam portions to detect a tangential error signal.
The photodetecting unit divides the light beam into first, second, third, and fourth light beam portions in a direction corresponding to a radial direction of the recording medium, and detects and outputs first, second, fourth, and third detection signals from the first, second, third, and fourth light beam portions, and the signal processor detects and outputs the tangential tilt error signal as a sum of a phase difference between the first and second detection signals and a phase difference between the third and fourth detection signals.
The photodetecting unit divides a part of the light beam with respect to an axis crossing an optical axis parallel to a tangential direction of the recording medium, and detects therefrom first, second, third, and fourth light beam portions in directions corresponding to the radial and tangential directions of the recording medium, where the first, second, third, and fourth light beam portions are arranged in order, counterclockwise or clockwise in a 2xc3x972 matrix and where a row and a column of the matrix are parallel to directions corresponding to the radial and tangential directions of the recording medium, respectively, and the signal processor detects and outputs the tangential tilt error signal as a sum of a phase difference between the first and second detection signals corresponding to the first and third light beam portions, respectively, and a phase difference between third and fourth detection signals corresponding to the second and fourth light beam portions, respectively.
To achieve another object of the present invention, there is provided an error signal detection apparatus for an optical recording/reproducing system including a light source emitting a light beam and an objective lens focusing the light beam to form a light spot on a recording medium, the apparatus including: a photodetecting unit dividing at least a part of the light beam passed through the objective lens after being reflected/diffracted from an information stream of the recording medium into light beam portions, and detecting the light beam portions; and a signal processor detecting phase differences between detection signals from the light beam portions to detect a defocus error signal.
The photodetecting unit divides the light beam and detects therefrom first, second, third, and fourth inner portions arranged counterclockwise or clockwise in directions corresponding to radial and tangential directions of the recording medium, and into first, second, third, and fourth outer portions which are outward from the first, second, third, and fourth inner portions in a direction corresponding to the tangential direction of the recording medium, wherein the first, second, third, and fourth outer and inner portions are arranged in a 4xc3x972 matrix, where a row and a column of the matrix are parallel to directions corresponding to the radial and tangential directions of the recording medium, and the first inner and outer portions are arranged in a column different from the fourth inner and outer portions, and where a sum of the detection signals from the first outer portion and the fourth inner portion is a first detection signal, a sum of the detection signals from the fourth outer portion and the first inner portion is a second detection signal, a sum of the detection signals from the second inner portion and the third outer portion is a third detection signal, and a sum of the detection signals from the third inner portion and the second outer portion is a fourth detection signal, and the signal processor detects the radial tilt error signal as a sum of a phase difference between the first and second detection signals, and a phase difference between the third and fourth detection signals.
The above and other object of the present invention are also achieved by an error signal detection apparatus for an optical recording/reproducing system including a light source emitting a light beam and an objective lens focusing the light beam to form a light spot on a recording medium, the apparatus including: a photodetecting unit dividing at least a part of the light beam passed through the objective lens after being reflected/diffracted from an information stream of the recording medium into light beam portions, and detecting the light beam portions; and a signal processor detecting phase differences between detection signals from the light beam portions to detect a radial tilt error signal.
In one embodiment of the error signal detection apparatus, the first, second, third, and fourth outer light beam portions form a 2xc3x972 matrix, wherein a row and a column of the matrix are parallel to directions corresponding to the radial and tangential directions of the recording medium, and the first and fourth outer light beam portions are in different columns; and the signal processor receives first, second, third, and fourth outer light beam portions and processes therefrom the first, second, fourth, and third detection signals. In this case, it is preferable that, when the light beam is divided into a first outer portion, an intermediate light beam portion, and a second outer portion in a direction corresponding to the radial direction, the photodetecting unit divides the first and second outer portions of the light beam into first through fourth light beam portions, and detects the first through fourth light beam portions. Further, the light beam is divided into a first outer portion, an intermediate portion, and a second outer portion in a direction corresponding to the radial direction of the recording medium, the photodetecting unit divides the intermediate portion of the light beam and detects therefrom first, second, third, and fourth light beam portions. The photodetecting unit divides the light beam and detects therefrom the first through fourth light beam portions.
In another embodiment of the error signal detection apparatus, the photodetecting unit divides the light beam into a first outer portion, an intermediate portion, and a second outer portion in a direction corresponding to a tangential direction of the recording medium, and divides the first and second outer portions and detects therefrom first, second, third, and fourth outer light beam portions in the direction corresponding to the tangential direction of the recording medium, and arranged counterclockwise or clockwise in order, and/or divides the intermediate portion and detects therefrom first, second, third, and fourth inner light beam portions in directions corresponding to a radial direction and the tangential direction of the recording medium, where the first, second, third, and fourth outer light beam portions are arranged counterclockwise or clockwise, in order. The signal processor detects the defocus error signal as a sum of a phase difference between a first detection signal from the first outer light beam portion and/or the second inner light beam portion and a second detection signal from the second outer light beam portion and/or the first inner light beam portion, and a phase difference between a third detection signal from the third inner light beam portion and/or the fourth outer light beam portion and a fourth detection signal from the third outer light beam portion and/or the fourth inner light beam portion.
In this case, the first, second, third, and fourth outer light beam portions form a 2xc3x972 matrix, wherein a row and a column of the matrix are parallel to directions corresponding to the radial and tangential directions of the recording medium, and the first and fourth outer light beam portions are in different columns; and the signal processor receives first, second, third, and fourth outer light beam portions and processes therefrom the first, second, fourth, and third detection signals.
The first, second, third, and fourth inner light beam portions form a 2xc3x972 matrix, wherein a row and a column of the matrix are parallel to directions corresponding to the radial and tangential directions of the recording medium, and the first and fourth inner light beam portions are in different columns; and the signal processor receives first, second, third, and fourth inner light beam portions and processes therefrom the first, second, fourth, and third detection signals.
The photodetecting unit divides the first and second outer portions of the light beam and detects therefrom the first, second, third, and fourth outer light beam portions arranged counterclockwise or clockwise, in order, parallel to a direction corresponding to the tangential direction of the recording medium, and divides the intermediate portion and detects therefrom the first, second, third, and fourth inner light beam portions arranged counterclockwise or clockwise, in order, parallel to directions corresponding to the radial and tangential directions of the recording medium, wherein the first, second, third, and fourth outer and inner portions are arranged in a 4xc3x972 matrix, where a row and a column of the matrix are parallel to directions corresponding to the radial and tangential directions of the recording medium, and the first and second outer portions are located in different columns, and the signal processor outputs the sum of the phase difference between the first detection signal, which is a sum of the detection signals from the first outer light beam portion and the second inner light beam portion, and the second detection signal, which is a sum of the detection signals from the second outer light beam portion and the first inner light beam portion, and the phase difference between the third detection signal, which is a sum of detection signals from the third inner light beam portion and the fourth outer light beam portion, and the fourth detection signal, which is a sum of the detection signals from the third outer light beam portion and the fourth inner light beam portion.
In still another embodiment of the error signal detection apparatus, the photodetecting unit divides the light beam into first, second, third, and fourth light beam portions in a direction corresponding to a tangential direction of the recording medium, and detects and outputs first, second, fourth, and third detection signals from the first, second, third, and fourth light beam portions, and the signal processor detects and outputs the defocus error signal as a sum of a phase difference between the first and second detection signals and a phase difference between the third and fourth detection signals.
An error signal detection apparatus for an optical recording/reproducing system including a light source emitting a light beam and an objective lens focusing the light beam to form a light spot on a recording medium, the apparatus including: a photodetecting unit dividing at least a part of the light beam passed through the objective lens after being reflected/diffracted from an information stream of the recording medium into light beam portions and detecting the light beam portions; and a signal processor detecting phase differences between detection signals from the light beam portions to simultaneously detect two or more error signals, wherein the error signals include a tangential error signal, a defocus error signal, and a radial tilt error signal.
These together with other objects and advantages, which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.

Error signal detection apparatus for an optical recording/reproduction system


Apparatus and methods for protected content access, browsing and transfer over a network. In one embodiment, the network comprises a premises (e.g., residential) LAN, and the apparatus comprises a server and renderer consumer premise equipment (CPE). The renderer CPE scans the network to search for a server CPE that implement a compatible security framework. The renderer authenticates itself with the server, and the server allows content browsing and selection access only to an authorized and authenticated renderer. A negotiation and exchange protocol comprises messages exchanged between the renderer and the server that include one or more of device identification, encryption key exchange, digital certificates and information regarding security package used by each CPE.

1. Field of Invention
The present invention relates generally to the field of content (e.g., multimedia, audiovisual, data, applications, etc.) delivery over a network. Specifically, in one aspect, the invention relates to the methods and apparatus for enforcing digital rights within a premises network where a variety of devices implementing different security packages may be in communication with one another.
2. Description of Related Technology
Recent advances in digital information processing have made a wide range of services and functions available for delivery to consumers at their premises for very reasonable prices or subscription fees. These services and functions include digital programming (movies, etc.), digital video-on-demand (VOD), personal video recorder (PVR), Internet Protocol television (IPTV), digital media playback and recording, as well high-speed Internet access and IP-based telephony (e.g., VOIP). Other services available to network users include access to and recording of digital music (e.g., MP3 files), as well local area networking (including wire-line and wireless local area networks) for distributing these services throughout the user's premises, and beyond.
Increased deployment of wireless interfaces such as WiFi, WiMAX and Bluetooth have also increased the prevalence and opportunity for ad hoc networking; i.e., substantially spontaneous or flexible network topologies between as few as two different entities.
Currently, many of these services are provided and delivered to the user via a wide variety of different equipment environments including, inter alia, cable modems, WiFi hubs, Ethernet hubs, gateways, switches and routers, computers, servers, cable set-top boxes, PSTNs, cellular telephones/smartphones, PDAs, and portable digital music devices such as the Apple iPod™. Additionally, the services associated with such technology are typically provided by multiple vendors including e.g., a cable service provider (e.g., MSO), cellular service provider (CSP), wireless service provider (WSP), VoIP service provider, music download service, Internet service provider (ISP), PSTN telephone service, etc.
Some improvements in digital service integration have been made over time. For example, cable system subscribers (such as those of the Assignee hereof) can now access VOD, PVR, PPV and broadcast services simultaneously, as well a Internet access via cable modem, and even digital telephony (e.g., VOIP). However, these functions are still substantially disparate in terms of their hardware and software environments (i.e., the user must have a cable modem, set-top box, VoIP telephony unit, PC, etc.), and "cross-over" between the environments (e.g., moving content or data from one environment to the other) is quite limited.
Furthermore, the movement of content delivered by these services within the user's premises (or even outside) is substantially frustrated, largely due to concerns relating to protection of valuable (e.g., copyrighted) content and surreptitious reproduction and distribution. Such unauthorized reproduction and distribution not only detracts from the network operator's revenue and commercial viability, but also that of the content source (e.g., movie studio, recording studio/artist, etc.).
Moreover, the lack of a comprehensive and effective scheme for control of content within the user domain effectively precludes content providers from releasing new content over cable or satellite networks contemporaneous with its availability over retail or rental outlets, due in large part to unauthorized access, reproduction and distribution concerns. Stated simply, new release content availability over cable typically lags that of rental/retail, due in large part to the lack of an effective control mechanism for the content once it is delivered to the user domain.
Accordingly, a number of existing technologies have heretofore been developed employed by network operators in order to attempt to frustrate surreptitious access, copying and distribution of valuable content. These technologies include: (i) conditional access (CA), (ii) encryption, (iii) the establishment of trusted domains (TDs), and (iv) digital rights management (DRM).
Conditional Access
Conditional access (CA) technologies are typically incorporated into content-based networks, such technologies including the digital encoding of various types of data including audio and video programming and music. Conditional access can generally be defined as the control of when and how a user may view and use the associated programming or information. Different types of conditional access may be desirable in a network delivery system in order to, e.g., accommodate improvements in the technology over time, as well as different conditional access attributes such as security and category of programming or user access level.
A variety of traditional methods of conditional access exist including, e.g., "Powerkey", NDS, and DigiCipher. A generalized conditional access model is also provided by the well-known DVB (Digital Video Broadcasting) Specification TS 101 197 V1.2.1 (02/02), DVB SimulCrypt; Part 1: "Head-end architecture and synchronization", and TS 103 197 V1.2.1 (02/02): "Head-end Implementation of SimulCrypt", each incorporated herein by reference in its entirety. These can be implemented using, for example, the so-called "CableCard" plug-in security module access technology (also known as a "a point-of-deployment (POD) module"). See, e.g., the CableCard-Host interface specification, which defines the interface between a digital cable receiver or STB (Host device) and the CableCard device provided by the MSO/cable operator. CableCard was developed to satisfy certain security requirements to allow retail availability of host devices, e.g., set-top boxes, digital cable ready televisions, DVRs, personal computers (PCs), integrated digital televisions, etc., for receiving cable services. The CableCard, comprising a PCMCIA device, can be inserted into a host device, allowing a viewer to receive cable systems' secure digital video services, e.g., pay per view TV, electronic program guides, premium subscription channels, etc.
Specifically, the CableCard contains conditional access functionality, as well as the capability of converting messages to a common format. Thus, the CableCard provides a cable operator with a secure device at the subscriber premises, and acts as a translator so that the host device needs to understand a single protocol, regardless of the type of the network to which it is connected.
Encryption
In many content-based networks (e.g., cable television systems), the client device or consumer premises equipment (CPE) receives, through the cable TV network, programming content which may be encrypted, e.g., in accordance with the data encryption standard (DES) technique or Advanced Encryption Standard (AES), to secure its delivery.
DES is a well-known symmetrical cipher that utilizes a single key for both encryption and decryption of messages. Because the DES algorithm is publicly known, learning the DES key would allow an encrypted message to be read by anyone. As such, both the message sender and receiver must keep the DES key a secret from others. A DES key typically is a sequence of eight bytes, each containing eight bits. To enhance the DES integrity, the DES algorithm may be applied successive times. With this approach, the DES algorithm enciphers and deciphers data, e.g., three times in sequence, using different keys, resulting in a so-called triple DES (3DES) technique.
The Advanced Encryption Standard (AES), also known as Rijndael, is a block cipher adopted as an encryption standard by many entities including the U.S. government. It is used worldwide, as is the case with its predecessor, DES. AES was adopted by National Institute of Standards and Technology (NIST) and was codified as US FIPS PUB 197 in November 20 AES provides a much higher level of encryption than DES or 3DES, and hence is increasingly being integrated into applications where strong protection is desired, including the delivery of content over cable or other content-based networks.
In contrast to the DES or AES techniques, a public key encryption technique, e.g., an RSA technique (named for its developers, Rivest, Shamir, and Adleman), uses two different keys. A first key, referred to as a private key, is kept secret by a user. The other key, referred to as a public key, is available to anyone wishing to communicate with the user in a confidential manner. The two keys uniquely match each other, collectively referred to as a "public key-private key pair." However, the private key cannot be easily derived from the public key. A party wishing to send a message to the user may utilize the public key to encrypt a message before transmitting it. The user then utilizes the private key to decrypt the message. Conversely, the private key may be used to encrypt a message, in which case the message can subsequently be decrypted with the public key. For example, the keys for the RSA algorithm are mathematically generated, in part, by combining prime numbers. The security of the RSA algorithm, and the like, depends on the use of very large numbers for its keys, which typically are 512 bits long or longer.
"Trusted Domains"
Another related approach for content protection comprises the creation and enforcement of a "trusted domain" or TD. Specifically, such a trusted domain comprises an area (physically or virtually) within which programming or other content is protected from unauthorized access, distribution and copying. For example, in a cable network, a trusted domain may include not only the network portion where programming content traditionally is secured by, and within total control of, a cable operator (including, e.g., the headend, HFC delivery network, etc.,) but also user devices or CPE 106 at subscribers' premises which are capable of receiving and securely storing programming content. Using the trusted domain approach, the network operator can guarantee certain subscriber access, distribution, and usage policy enforcement with respect to content held within the domain. For example, a digital representation of a movie held within an operator's TD (e.g., on a hard drive of a user device) cannot be distributed over the Internet, wireless network, etc. in viewable form, and cannot become a source for duplication of multiple viewable copies.
One exemplary approach of implementing a trusted domain, described in co-owned and co-pending U.S. patent application Ser. No. 11/006,404 filed Dec. 7, 2004 and entitled "Technique For Securely Communicating And Storing Programming Material In A Trusted Domain" (TWC 03-17), which is incorporated herein by reference in its entirety, comprises using two cryptographic elements (e.g., encryption keys), associated with a user and his/her client device(s), respectively, that control access to content stored in the client device(s) within the domain. The trusted domain is preserved with respect to the stored content so long as the content remains encrypted and continues to be managed under the prescribed key management methodology, regardless of which device stores the content. Once the content itself is decrypted, e.g., by a conditional access (CA) mechanism when data is sent from the DVR CPE to a television monitor for display, the decrypted content is no longer within the trusted domain.
Closely related to the concept of a trusted domain is the so-called ASD or "Authorized Service Domain". ASD is a digital content management technology that is used by cable operators to protect their distributed content. ASD is defined by NGNA and CableLabs, and specifies a protocol for devices to exchange content protection information and/or security packages. These security packages typically pertain to service entitlement packages on the cable network. The security mechanism utilized with the ASD framework is typically tied to the security credentials of a multi-stream CableCard (see discussion of CA above), or secure microprocessor (SM) under the so-called DCAS or Downloadable Conditional Access System paradigm.
Digital Rights Management (DRM)
Another approach used to control the distribution and use of protected content within a content-based network is to employ so-called digital rights management (DRM). For example, Media rights management systems such as the Microsoft Windows® Media Digital Rights Manager (DRM), may be used as well. The Windows® Media Player Version 9 comprises audio and video codecs, the Windows Media Encoder, Windows Media Server, Windows Media Software Development Kit (SDK), Digital Rights Management (DRM) technology, and an extensibility model that allows integration into third-party solutions.
According to one such DRM approach, a digital media or content file is encrypted and locked with a "license key." The license key is stored in a license file or other data structure which is distributed separately from the media or content. A user can obtain the encrypted media file by, e.g., downloading it from a web site, purchasing it on a physical media, etc. To play the digital media file, the user must first acquire the license file including the license key for that media file. The user acquires the license key by accessing a pre-delivered license (which includes license terms or policies). Alternatively, when the user plays the file for the first time, a procedure is invoked for retrieving the license via a network connection or other delivery mode (e.g., the Internet). After obtaining the license with the license key, the user is able to access the media file according to the rules or rights specified in the license policies.
Another approach to DRM (see, e.g., the RealNetworks "Helix" Platform and Community approach) comprises encrypting a content file (typically performed by the system operator) to create a secured content file, thereby requiring a cryptographic key to access the content in the file. The key is included within a retailer's database, and the secured content file is distributed to users by, e.g., Internet connection or offline distribution of CDs. The retailer itself sets usage rules and policies for licensing the content. A user contacts the retailer's web server, such as via a trusted software client, in order to obtain a license to access the encrypted content. The retailer's web server requests certain rights from the operator's license server, the latter which creates a license containing the key for the requested content file. This license is given to the retailer (e.g. via the web server), which delivers the license to the trusted client of the user. The trusted client retrieves the content file, and uses the received key to access the content.
"Plug and Play" Technologies
A number of different approaches to device data interface are known in the prior art. More recently, so-called "plug and play" technologies have evolved in order to facilitate the ability for a user to connect two or more devices together (including related controllers, or "control points"), and effectively have them be configured appropriately for communication without further user intervention. One of the best known of these technologies is the Universal Plug and Play (UPnP) approach, which comprises a set of protocols that allow devices to connect seamlessly in a peer-to-peer fashion and exchange data, and also to simplify the implementation of networks in the home and enterprise environments. This seamless connectivity is accomplished in large part via use of device control protocols built upon open, Internet-based communication standards such as TCP/IP, UDP and HTTP.
Hallmarks of UPnP include (i) media and device independence, (ii) operating system and programming language independence, and (iii) lack of specific device drivers. UPNP does not constrain the design of application programming interfaces (APIs) for applications running on interface control points. UPNP enables control over device user interface and interaction using a browser, as well as conventional application programmatic control.
The UPNP architecture also supports zero-configuration and automatic discovery, whereby a device can dynamically join a network, obtain an address, announce itself, convey its capabilities upon request, and learn about the presence and capabilities of other devices.
Deficiencies With The Prior Art
Conditional access (CA) paradigms currently in use, such as the aforementioned Powerkey and DigiCipher approaches, are restricted in their scope and not generally extensible beyond the user's set-top box or the equipment used to obtain digital content from a network service. So, for example, the user would generally be prohibited from transferring streamed or downloaded content to their WiFi enabled laptop or PC, or via a USB or FireWire port, since proper conditional access and content protection support does not exist in these devices or by virtue of the interfaces themselves.
Accordingly, content sharing between "authorized" devices is typically performed in the prior art over a vendor-specific or proprietary interface that is specific to a given conditional access system deployed in that network. As previously discussed, the Authorized Service Domain (ASD) sets forth a protocol for devices to exchange content protection information and security packages on, e.g., cable networks. These security packages may pertain, for example, to access or entitlement packages for services on the cable network. However, no mechanism or protocol is provided under the ASD approach (or otherwise) for the protected access and distribution of content on a premises network, especially one serving devices having potentially diverse hardware, software, and security environments.
For example, in a typical home networking environment, content delivered to and stored at the premises (e.g., on a DVR) needs to be delivered to multiple rooms or devices within or associated with the premises. Such "multi-room" DVR or protected content transfer between devices within or associated with the home requires a secure and user-implemented mechanism for exchanging security information. Ultimately, credentials of the devices in the home network have to be verified against a "trusted" device list within the operator network (e.g., at the cable head end) or another authentication node. Using prior art approaches, this has the disability of being overly centralized and hence somewhat inflexible, especially with respect to premises networks which may be both high dynamic in their topology or participants, as well as high heterogeneous in terms of their hardware/software environments, including within the premises network itself (e.g., a WiFi AP may distribute content to a laptop or hand-held computer via a wireless link, or a converged premises device may interface with any number of other devices such as DSTBs, laptops, cable ready televisions, DVRs, etc. using two or more communication media such as indigenous coaxial cable, CAT-5 cabling, wireless, etc.). Hence, premises networks are highly dynamic and often composed of many different types of devices, thereby requiring both a flexible and substantially "universal" mechanism for security information exchange and control/transfer of protected content.
Thus, improved apparatus and methods for facilitating the distribution of digital content within a user premises are needed. Such improved apparatus and methods would ideally operate at the application level (thereby allowing ready implementation on any number of different platforms and environments in a substantially agnostic fashion), and provide users the ability to browse and transfer content between equipment with different vendor's security package implementations.
Such improved apparatus and methods would also preferably be implemented in a manner that is both substantially automated and transparent to the user, and which can leverage the capabilities of existing or planned industry-standard interface technologies such as Universal Plug and Play (UPnP) if desired.

Methods and apparatus for premises content distribution


A resonant assembly for identification of a buried asset comprising first and second resonant members each configured to resonate at a respective different resonant frequency when excited by an electromagnetic field. The resonant assembly is arranged to cause a near-field coupling of transmit and receive antenna of a detector at the first and second resonant frequencies such that identification of the resonant assembly is performed at least in part according to the frequencies of the coupling.

Determining a location and identity of a buried asset without accurate written records can be a challenging task. In some cases, determination of the location is performed by systematically digging holes in ground until the asset is found. In other cases, ground penetrating radar (GPR) is used, assets being located by detecting a signal reflected by the asset. (Reference to GPR includes radiation having a frequency in the range of from around 200 MHz to around 1 GHz).
Use of GPR for locating buried assets suffers the disadvantage that radiation can be reflected by a number of features of a volume of ground, including variations in moisture content, solids composition, the presence of wildlife, and voids formed for example by tunnelling wildlife. Thus it can be difficult to reliably identify a location of a buried asset.
Acoustic techniques have also been used to identify buried assets and found to suffer similar disadvantages to GPR techniques.
It is also known to attach a radio frequency identification tag (RFID tag) to a non-buried asset such as items for sale in a store in order to enable identification of the asset using a suitable RFID tag reader. Typically, an RFID tag is placed in an inductive RF magnetic field to induce a flow of electrical current in the tag. The flow of current is used to generate an RF transmission by the tag to the reader.
Inductive magnetic fields are mostly in the near field, however, and the use of such RFID tag systems to locate and identify assets more than a few meters from the reader is generally not easy.
In the case of buried assets the problem is exacerbated since inductive RF electromagnetic waves are more strongly attenuated by soils than by air.
More recently, far-field RFID technology has been developed. However, RFID readers are incapable of generating sufficiently large excitation signals to detect RFID tags at depths below a surface at which many assets of commercial interest are buried.
U.S. Pat. No. 3,769,623 discloses a dichroic plate for passing radiation within a particular frequency band and reflecting radiation outside of that frequency band. The dichroic plate has slots provided therein dimensioned to pass radiation of a selected frequency.
U.S. Pat. No. 5,837,926 discloses mines having tuned passive electromagnetic resonants to enhance radar detection.
The UK HSE (Health Safety and Executive) Enforcement Policy for Replacement of Iron Gas mains 2006 has developed legally binding requirements on the UK gas distribution network operators for the replacement of ageing cast iron gas mains pipes with pipes formed from plastics materials.
However, current methods used to trace plastics-based pipes are either inefficient or very expensive. This hampers replacement and repair operations leading to unnecessary delays. Excavations often result in accidental damage to third party assets, casualties and traffic congestion. Furthermore, the Traffic Management Act and Records Code of Practice for buried assets largely suffer from inaccurate records.
It is desirable to enhance the visibility of buried assets such as plastics pipes.

Resonant assembly, system and method for identification of a buried asset


A scene of an image sequence is compressed using a number of foveation zones, each foveation zone being weighted based on a probability of a viewer looking at a corresponding portion of the first scene. Each foveation zone in the scene has a corresponding resolution to ensure that at least one object therein is viewer-recognizable. Another scene of the image sequence is compressed using a different number of foveation zones, each foveation zone being weighted based on a probability of a viewer looking at a corresponding portion of the second scene. Each foveation zone in the other scene has a corresponding resolution to ensure that at least one object therein is viewer-recognizable.

1. Field of the Invention
The present invention relates to image compression methods which use foveation.
2. Description of the Related Art
Foveation is a compression method in which an image is compressed so that it matches an ability of a human visual system to detect detail in a peripheral visual field. In a typical foveation scheme, resolution of the image is degraded in direct correlation to the resolution fall-off function of the human visual system. Methods of image compression using foveation are disclosed in U.S. Pat. No. 6,252,989 to Geisler and Kortum. Foveation is a powerful method of image compression because of high compression rates and perceptually lossless images which result. Drawbacks of the method include requiring real-time knowledge of where a user is looking, and not easily supporting multi-viewer environments. Further, while degrading the image in direct correlation to the resolution fall-off function of the human visual system allows for maximum bandwidth reduction, it does not easily support deviations from the calculated point of gaze.

This patent is subject to a terminal disclaimer.

Multi-resolution predictive foveation for bandwidth reduction of moving images


An overvoltage resistor formed in the substrate semiconductor material of an integrated circuit. The overvoltage resistor is formed from a resistive layer formed over a well of a semiconductor material having a conductivity type which is opposite to the conductivity type of the substrate material. The overvoltage resistor is not connected to the voltage supplies of the integrated circuit, thereby eliminating the virtual pn-diode which would otherwise be formed between the well and the substrate and allowing the overvoltage resistor to protect the integrated circuit from voltages outside the range of supply voltages.

Integrated circuits are typically designed to communicate signals with external devices through bonding pads on the periphery of the integrated circuit. Circuitry contained on the integrated circuit is designed to operate within predetermined voltage supply levels, which depend upon the process technology used, to produce the integrated circuit. In contrast, external circuitry does not necessarily operate within the same voltage limits as the circuitry on the integrated circuit. This presents a conflict which must be resolved in order for the integrated circuit to be as compatible as possible with external circuitry.
An example of such a situation occurs with an integrated circuit which is designed to receive signals according to the RS422 interface. This interface is defined in "EIA Standard RS422A," Electronics Industry Association, Dec. 1978. It is a differential, balanced voltage interface capable of high data rates over long distances. It can accommodate rates of 100 kilobaud over a distance of 4,000 feet, or rates of up to 10 megabaud. This high performance stems from the advantages of a balanced double input signal configuration which is isolated for ground noise currents. Because is it a differential interface, the RS422 interface is also immune to both fluctuating voltage potentials between system ground references and common mode electromagnetic interference.
As a differential interface standard, the RS422 interface will operate correctly as long as an appropriate differential voltage is maintained between the standard two input signal lines, regardless of the absolute voltage levels of those lines. However, due to the common mode voltage changes to which the two input voltages are susceptible, especially over long distances, the voltages on the signal lines according to an RS422 standard may be outside of the voltage range of the integrated circuit. Such voltages have the potential of damaging the chip by triggering "latch-up," as a result of forward-biasing the parasitic diodes at the input pads to the integrated circuit. This latchup phenomenon is described in "Latchup in CMOS Technology," by Ronald R. Troutman, Kluwer Publishers, 1986.
Several techniques may be used to protect the integrated circuit from latch-up damage while allowing it to continue operating. One technique might be to generate higher voltage supplies on the integrated circuit. This can be accomplished by incorporating a charge pump on the circuit. However, the supplies cannot be raised due to drain-to-source breakdown voltages, hot electron effects, and impact ionization problems.
Another approach to protect the integrated circuit is to use circuits that can tolerate signals larger than the supply voltages. This can be accomplished by increasing the thickness of the insulating layer on the MOS field effect transistors (MOSFETs) of the chip. Unfortunately, increasing the thickness of the gate layer decreases the operating speed of the MOSFET's circuitry.
A third technique to protect the integrated circuitry is to scale the signal voltages to be within the limits of the integrated circuits voltage supplies. This can be accomplished by dropping the large input voltages across resistors between the integrated circuits' input pads and the MOSFET circuitry of the chip.
The resistive layers available in digital MOS processes are polysilicon, a conductive "well," an active layer in the substrate, and an active layer in a conductive well. Until the recent introduction of silicide processing, polysilicon was useful as a resistive element. Silicide processing reduces the sheet resistance of polysilicon to improve the speed of the circuitry. Unfortunately, this also limits the use of polysilicon as a resistor because a much longer length of silicided polysilicon is required to produce a given resistance.
A "well" resistor is not usable in standard bulk complementary metal oxide semiconductor (CMOS) technology because the parasitic pn diode between the well and the substrate prevents signal excursions beyond one of the chip's voltage supplies. A resistor made by placing an active layer in the substrate has the same problem as the "well" resistor, as does a resistor made by placing an active layer in a well connected to a supply voltage.
Accordingly, it is desirable to produce a resistive element that can be used on integrated circuits containing CMOS circuitry without limiting the speed of the circuitry, while allowing the input voltages to fall outside of the range of the integrated circuits voltage supplies.

Overvoltage resistor and method for its manufacture


Methods for eliminating and/or mitigating bridging and/or leakage caused by the contamination of a dielectric layer with fragments and/or residues of a conductive material are disclosed. The methods involve exposing a semiconductor substrate with a dielectric layer contaminated with fragments and/or residues of conductive materials to one or more conductor and/or dielectric etches. The disclosure by eliminating and/or mitigating metal bridging and/or leakage can provide one or more of the following advantages: high device reliability, decreased manufacturing cost, more efficient metallization, and increased performance.

In the semiconductor industry, there is a continuing trend toward higher device densities. To achieve these high densities there have been, and continue to be, efforts toward scaling down device dimensions (e.g., at sub-micron levels) on semiconductor wafers. In order to accomplish such high device packing densities, smaller and smaller feature sizes are required. This includes the width and spacing of interconnecting lines, spacing and diameter of contact holes, and the surface geometry, such as corners and edges, of various features. The dimensions of and between such small features can be referred to as critical dimensions. With an ever increasing number of integrated circuit features being formed on a circuit die, the importance of properly designing patterns to form structures that are isolated and non-interfering with one another has also increased.
Conventional semiconductor devices typically comprise a semiconductor substrate and a plurality of dielectric and conductive layers formed thereon. An integrated circuit contains numerous microelectronic devices, such as metal oxide semiconductor field effect transistors (MOSFETs), a plurality of conductive patterns comprising conductive lines separated by interwiring spacings, and a plurality of interconnect lines, such as bus lines, bit lines, word lines and logic interconnect lines. Such interconnection lines, made of metal interconnect materials, generally constitute a limiting factor in terms of size (width) and various functional characteristics of the integrated circuit.
With the increase in metal levels and line length, and the corresponding decreases in line width, there is a need in the art for systems and methods that improve critical dimensions and electrical performance of interconnect structures and conductive patterns.

Metal/oxide etch after polish to prevent bridging between adjacent features of a semiconductor structure


An apparatus guides first and second assembly components into a predetermined configuration, each assembly component including an opening. When the assembly components are aligned into the predetermined configuration, their openings align to define a cavity for receiving a stepped dowel to fasten the components together. The guiding apparatus includes a stepped dowel member having successively-smaller dowel sections, and a collar member floating around the base of the stepped dowel member. The stepped dowel member tip can be passed through the first assembly component opening and inserted into the second assembly component opening, drawing the components into the predetermined configuration. When the components are aligned into the predetermined configuration, the collar member engages the first assembly component opening and the stepped dowel member engages the second assembly component opening. The guiding apparatus can be disengaged, freeing the dowel-receiving cavity to accept a stepped dowel for fastening the assembly components together.

To assemble a multi-component assembly, individual components must be aligned into specific positions with respect to other components, in order to allow fastening mechanisms to fix the components together in the desired, assembled configuration for the multi-component assembly. This can be difficult when especially the components are large or heavy, or when the components must be manipulated into a precise configuration. Assembly is problematic where the alignment positions are not easily seen or detected by the individual putting together the assembly. Such assembly can be particularly difficult where there is limited space in which to manipulate the components during the assembly process.
For example, prefabricated multi-panel wall assemblies can be assembled from multiple smaller wall panel components, and then secured onto a floor component and secured to a ceiling component. Such components are often large and weighty, and the fastening mechanisms for joining them often require that the components be arranged with great precision to allow the fastening mechanisms to fix the components together. Often, such components are prefabricated to include structures for engaging the fastening mechanisms, and those structures must be sufficiently aligned to accept the mechanism that fastens them together.
Compared to the assembly structures, the fastening mechanisms can have a much smaller relative size, which can make it difficult align them together, especially where there is little room for error in alignment. During the assembly process, the components themselves can block the assembly person aligning the components from using his senses to determine if the components are properly positioned.
There is a need for a mechanism for guiding two or more components into an assembly system. For example, there is a need for a device for aligning prefabricated wall system components into the configuration required to enable fastening mechanisms to engage and fix the components together. There is a particular need for a guiding mechanism that can be deployed to quickly and accurately align the prefabricated components of such wall systems, and other assembly systems, together.
There is a particular need for a guidance mechanism that can be quickly and easily removed from the assembly system after alignment of the wall system components is complete, leaving the components aligned in the assembly configurations with respect to each other. There is a need for a transient guiding apparatus that can align the components precisely and then be removed without disturbing the position of the aligned components.
There is a particular need for a guiding apparatus that can be employed while the assembly components are in transit, to guide the assembly pieces into optimum configurations for fastening them together. It would be useful to have a guiding apparatus that can be deployed before the assembly pieces physically contact each other, especially after one of the pieces has been lifted and before it has been deposited to its destination. At such a time, when the weight of a component is supported by a transport device, relatively little force would be required for precise alignment of the component.
There is also a need for an apparatus that can be used to transiently manipulate the position of such large components that can be used in concert with other devices that have the power or size to accomplish the handling of the large components. There is a need for a transport apparatus that can form a temporary engagement with the large assembly components, accomplish the positioning of the components, and then be disengaged from the assembly components without damaging, altering, or changing the relative positions of the components.
There is a need for such a transport apparatus that is portable and usable in limited spaces, having a structure that enables it to transiently bear the weight of assembly components having a much greater comparative size or weight. There is also a need for a transport apparatus that is made of a minimal number of components, that can be quickly and readily used and removed, that can position the assembly components quickly and readily, and then be extracted from the aligned components so as to facilitate the engagement of fastening mechanisms.
There is a need for a method of using common construction components or elements to effect the alignment of the assembly components into predetermined configurations, combining them in such a way as to create a transport apparatus for moving large or heavy assembly components into desired configurations, to facilitate the engagement of the fastening mechanisms that will fix the components into the assembled configuration.

Guidance apparatus for assembly of construction panels


An apparatus for treating clothes includes an accommodating space, an air supply unit, a duct unit, a filter unit, a substance removal unit and a collection unit that is separate from the filter unit and the substance removal unit. The accommodating space is configured to receive one or more clothing articles. The air supply unit is configured to supply air to the accommodating space. The duct unit is configured to guide discharge of air from the accommodating space. The filter unit is positioned to filter substances from air discharged from the accommodating space through the duct unit. The substance removal unit is configured to move substances remaining on a portion of the filter unit. The collection unit is configured to collect substances moved from the filter unit by the substance removal unit.

In general, clothes treatment apparatus are electric appliances used to perform washing, drying or both washing and drying of clothes. Clothes treatment apparatus include washing machines, dryers and machines having both washing and drying functions. In a conventional clothes treating apparatus capable of drying clothes, it may be necessary to remove foreign substances, such as lint, from the discharged air. Therefore, it may be desirable to filter air discharged from a clothes treating apparatus capable of drying clothes.


Technologies are provided for synchronizing and joining multiple calls from a first thread and one or more second threads to execute a particular code segment. In response to a call from the first thread to execute the particular code segment, a task synchronizer module calls the particular code segment on behalf of the first thread. When execution of the particular code segment starts, and a call is received from a second thread to execute the particular code segment after receiving the call from the first thread, the task synchronizer module suspends execution of the particular code segment so that the second thread awaits for the execution of the particular code segment on behalf of the first thread to complete. When execution completes, a result value or exception is stored in a task object, and the second thread can read the result value or the exception.

With the development of complex computing applications, modern application programming has become quite intricate. Application programs created these days pose a requirement for extensive processing resources. However, available processing resources may not satisfy this requirement. Hence, it is essential that the available processing resources be optimized. At the same time, the application program needs to be run as efficiently as possible, while still maintaining the process complexities. Use of multithreaded programming has proved to be beneficial in optimizing the available processing resources as well as efficiently running the application program.
In multithreaded programming, an application program is written as a set of parallel activities or threads. A thread is an instance of a sequence of code that is executed as a unit. The partitioning of an application program into multiple threads results in easily manageable and faster program execution.
Each thread requires certain resources like processor time, memory resources, and input/output (I/O) services in order to accomplish its objective. An operating system allocates these resources to various threads. The operating system provides a scheduling service that schedules the thread for running on the processor.
In some cases, multiple threads in an application make identical calls at the same time. The exact same data is returned. Each thread runs the same exact code to parse the network response. A traditional lock makes each thread wait to take its turn, and then once a thread has it's turn it will execute the code. However, if many threads are waiting on a lock then each thread will wait to take it's turn and then execute that code. This means that the same execution takes place multiple times. This approach can be inefficient, waste bandwidth, and slow because multiple threads are fighting for the same network resources.
It would be desirable to make the thread processing more efficient so that it consumes less computing resources than a conventional approach where each thread is executed independently at or near the same time.

Method and system for synchronizing and joining multiple calls to the same asynchronous code segment


A medical device has a fluid port (2), a tube (20), a socket (4), which can be connected to the fluid port and to the tube with freely selectable rotation positions. The tube is provided with a transponder (22) and with a writing and reading device for communication with the transponder, which has an antenna (24) in the area of the fluid port. The socket is provided with a coil (5, 6) each, whose axis of rotation is directed essentially coaxially to the axis of rotation about which the relative rotation position of the socket is variable. The two coils are connected by electric lines (8), to which at least one capacitor (9) is connected as a circuit component. The coils, the electric lines and the circuit component form an electric oscillatory circuit for transmitting signals between the writing and reading device and the transponder.

A typical example of such a medical device is a respirator (also known as a ventilator), at the breathing gas connection of which a tube can be connected via a socket, which said tube leads into the respiration circuit. At their ends facing the respirator, such tubes are provided with transponders, which make it possible for the respirator with an associated writing and reading device to exchange information with the transponder and to make available as a result information on the type and other properties of the connected tube. The antenna of the writing and reading device is located close to the breathing gas connection of the respirator; the antenna can surround this breathing gas connection, for example, concentrically.
One problem of such devices is that a certain distance between the antenna at the fluid port and the transponder at the tube is inevitable, because the socket is located between the tube and the fluid port. Since the range of radio frequency signals, which are exchanged between the antenna of the writing and reading device and that of the transponder, is limited, problems may arise in signal transmission. Another problem is that the connections of the socket to the fluid port, on the one hand, and to the tube, on the other hand, do not predetermine a fixed or predetermined rotation position of the fluid port and the socket, on the one hand, and the socket and the tube, on the other hand, i.e., the connections may take place, in principle, in any relative rotation position of the components in relation to one another, i.e., both the rotation position of the socket in relation to the fluid port and the relative rotation position of the socket in relation to the tube may vary over a relative angle of rotation of 360°. The position which the antenna of the transponder will assume relative to the antenna of the writing and reading device is unpredictable due to these circumstances.
Furthermore, the rotatable connection of the fluid port or the tube to the socket rules out an electrically conductive connection from practical points of view, because such a connection could be embodied only at a considerable design effort, for example, with sliding contacts.


A nondestructive testing apparatus includes a display section and a storage section which stores predetermined executable functions. Each of the predetermined functions is initially set to one of a permitted state and a disabled state, and one of a display state and a non-display state on the display section. In an initial state, at least one of the predetermined functions is set to the disabled state and the non-display state. The nondestructive testing apparatus can receive permission information which unlocks at least one of the predetermined functions initially set to the disabled state so as to be set to the permitted state, and unlocks at least one of the predetermined functions initially set in the non-display state so as to be in the display state. The apparatus displays an operation icon only with respect to all of the predetermined functions set to the display state.

1. Technical Field
The present invention relates to a nondestructive testing system that tests a subject without causing damage.
2. Related Art
Generally, in nondestructive testing systems, the number of processes in an executable range can be increased by a method of upgrading (renewing) firmware (a program) stored in the nondestructive testing systems.
For example, in a configuration method of an apparatus disclosed in PCT Japanese Translation Patent Publication No. 2009-516844, at least a part of the data for upgrading the apparatus is provided by an insert such as a memory card which is removable from the apparatus.
Such an insert stores installation data to efficiently upgrade the apparatus, application and user data, a program that in effect controls the apparatus, and a shutdown command to terminate the installation.
By connecting the insert to the apparatus, first an application is executed in the apparatus, and the application and user data stored in the insert is copied to a memory of the apparatus.
Then, by executing the shutdown command, the upgrade of the apparatus is terminated.
Further, in recent years, in digital cameras and the like, it has been possible to download the program for the upgrade of the firmware through the Internet.
By installing the downloaded program in the digital camera, the digital camera is able to execute a new function such as white balance correction or noise reduction.
For example, previously, in digital cameras, it had been difficult to perform processing on photographic images during and after photographing. However, by installing a program for upgrade, it is possible to execute a new function such as white balance correction or noise reduction.


A semiconductor light detector includes a first semiconductor layer of a first conductivity type having a multi-layer structure including a light absorbing layer and an avalanche multiplicating layer, an annular second semiconductor layer formed on the first semiconductor layer, a light detecting region formed by doping an impurity of a second conductivity type in a surface region of the first semiconductor layer, in such a manner that a peripheral portion of the light detecting region is located outside an inner periphery of the second semiconductor layer, the light deflecting region defining a first p-n junction in combination with the first semiconductor layer, and a guard ring formed by doping an impurity of the second conductivity type in a surface region of the second semiconductor layer to surround the peripheral portion of the light receiving region with the first semiconductor layer, the second p-n junction having a concentration gradient lower than that of the first p-n junction. By virtue of the presence of the second semiconductor layer, the junction depth of the peripheral portion of the light detecting region is less than that of the central portion of the light detecting region, and the junction depth of the guard ring is greater than that of the peripheral portion of the light detecting region. As a result, a sufficient guard ring effect can be obtained without a guard ring having a great junction depth.

1. Field of the Invention
The present invention relates to a semiconductor light detector utilizing an avalanche effect and, more particularly, to a semiconductor light detector having an improved guard ring structure and a method of manufacturing the same.
2. Description of the Related Art
In recent years, an avalanche photo diode (to hereinafter be referred to as an APD) has been used as a high-sensitivity light detector in such fields as optical fiber communication systems. An APD is a device utilizing avalanche-carrier multiplication of a semiconductor crystal, and has an avalanche region having a high electric field inside the device. For this reason, a guard ring structure is important to prevent local breakdown caused by electric field concentration in the avalanche region; in particular, in the peripheral portion of the avalanche region.
An optical communication system generally uses an APD which includes a light detection layer (light absorption layer) consisting of GaInAs (having a composition lattice-matched with InP) having high sensitivity in a low-loss range (wavelength; 1.3 to 1.5 .mu.m) of a quartz optical fiber, carriers generated in the light receiving layer being subjected to avalanche multiplication by InP.
Since a high electric field region necessary for avalanche multiplication is formed at a front portion of a p-n junction having a sharp concentration gradient (to hereinafter be referred to as a steeply graded junction), electric field concentration tends to occur at the end portion of the front portion, due to the curvature of the end portion, as a result of which a so-called local breakdown tends easily to occur.
In order to solve the above problem, a guard ring is formed. By arranging the guard ring, a p-n junction having a slow concentration gradient (to be referred to as a moderately graded junction hereinafter) is formed at the end portion of the front portion of the steeply graded junction.
In the moderately graded junction, a breakdown voltage is generally high and an electric field concentration effect due to the curvature is insufficient. Therefore, the guard ring can suppress the local breakdown. At this time, the depth of the moderately graded junction must be slightly larger than that of the steeply graded junction. If the steeply graded junction is too close to the moderately graded junction, the effect of the moderately graded junction is decreased. In addition, a method of equivalently increasing the curvature of an impurity doped interface can effectively suppress the local breakdown.
A conventional APD wherein a guard ring is formed will be described hereinafter with reference to FIGS. 1 to 4.
FIG. 1 is a sectional view showing an example of a conventional APD disclosed in Lecture Papers of the 46th Lectures of the Japan Society of Applied Physics, 1985, Autumn. In FIG. 1, an n-InP buffer layer 2, an n.sup.- -GaInAs light absorbing layer 3, an n.sup.- -GaInAsP (composition having an absorption edge wavelength of 1.3 .mu.m) intermediate layer 4, an n-InP avalanche multiplication/electric field relaxation layer 5, an n.sup.- -InP window layer 6, a p-type guard ring 8 for forming a moderately graded junction, a p-type light receiving region 9 for forming a steeply graded junction, an insulating layer 11, and a non-reflection coating layer are sequentially formed on an n-InP substrate 1. An electrode 13 is formed on an exposing surface of the light detection layer 9, and an electrode 14 is formed on a lower surface of the substrate 1.
In the APD having the above structure, a depletion layer extends under the p-type regions 8 and 9, and carriers generated in the light absorbing layer 3 are guided to a high electric field region concentrated in the p-n junction region and are subjected to avalanche multiplication. In the optical communication APD, in order to minimize a decrease in response speed due to the avalanche multiplication, the light detecting region 9 is generally formed close to the n-InP layer 5 to decrease the width of the high electric field region. Therefore, the junction defined by the guard ring 8 is formed to extend in the n-InP layer 5. However, since the impurity concentration of the n-InP layer 5 is relatively high, an effect of the moderately graded junction on the interface of the guard ring 8 tends to be insufficient, thus easily causing local breakdown. In the prior art shown in FIG. 1, a shallow guard ring is expanded in a longitudinal direction to prevent the local breakdown. This is equivalent to an increase in curvature of the peripheral portion of the guard ring. In such a prior art, however, the electric field value of the light detection layer 3 tends to increase because the moderately graded junction is deep under the steeply graded junction, and a current generated in a heterointerface or a dark current due to a tunnel current in the light detection layer 3 tends to be increased. The above problems are posed when the impurity concentration of the n-InP layer 5 is increased and the thickness thereof is decreased to achieve a high-speed operation.
FIG. 2 is a sectional view showing a prior art wherein the shape of the interface portion of the steeply graded junction is changed and the equivalent curvature of the interface is increased. This prior art is disclosed in the Institute of Electronics and Communication Engineers of Japan, the National Meeting, Lecture Papers C--172, 1988, Autumn. In this prior art, a guard ring providing the moderately graded junction is not formed, but only the shape of the interface portion of the steeply graded junction prevents local breakdown. This moderately graded junction is formed by thermal diffusion of Zn, Cd, or the like. A central light detecting region (projection) is formed by selective forced diffusion of an impurity. As a result, a high electric field region is formed in the central projection, and the electric field concentration in the projection interface is decreased.
In such a structure, a dark current is not unnecessarily increased, as compared with the prior art in FIG. 1, and an element almost free from the dark current can be obtained. In such a structure, however, in order to relax the curvature of the peripheral front portion of the steeply graded junction, relatively deep diffusion (about 6 .mu.m) is performed, and the thickness of the n-InP layer 6 must be increased as compared with that in diffusion (diffusion depth: 1 to 2 .mu.m) using a normal moderately graded junction (guard ring). For this reason, cost is undesirably increased to perform crystal growth. In addition, controllability of the diffusion depth is degraded because of deep diffusion, and flatness of the front portion of the diffusion region is easily damaged. Therefore, the nonuniformity of the light detection sensitivity undesirably tends to occur over the light detection region. In addition, when the front portion of the diffusion region approaches the n-InP layer 5 in order to achieve a high-speed operation of the device, local breakdown in the front peripheral portion tends to occur again. As a result, this structure is not suitable for a high-speed APD.
FIG. 3 shows a prior art wherein a part of the n-InP layer 5 on which the guard ring is to be formed is removed, and another n.sup.- -InP layer 6 is grown again. This prior art is disclosed in Japanese Patent Disclosure No. 61-220481. In this prior art, the guard ring providing the moderately graded junction is formed in the front peripheral portion of the steeply graded junction. However, since the thickness of the n.sup.- -InP layer 6 grown again is relatively large, the moderately graded junction can hardly affect the light detection layer 3. In addition, since the diffusion depth is normal and the shape of the diffusion front can be deformed at a regrowth interface, a substantially ideal guard ring structure can be obtained by performing optimization. Such an excellent structure is suitable for a high-speed APD, and problems on its characteristics can be substantially solved.
The drawbacks of the above structure are, however, caused by the such problems in a manufacturing method that a regrowth interface exists in the high electric field region and double crystal growth must be performed. More specifically, a perfect regrowth interface is required to withstand a high electric field wherein avalanche multiplication can be performed. Therefore, crystal regrowth almost free from an interface level is required. For this reason, the following method has been employed. That is, so-called "melt back" (etching in a growth furnace by crystal growth melt) is slightly performed by an LPE (liquid phase epitaxy) to clean the surface. By employing this method, a substantially perfect regrowth interface can be obtained. However, since the LPE is employed as a regrowth method, the following problems are posed. For example, a wafer size is limited, the flatness of the regrowth interface is easily damaged, and the number of factors to reduce a manufacturing yield is increased. In addition, since the thickness of the layer formed by the second crystal growth is large, i.e., 2 to 3 .mu.m, cost is undesirably increased because of the second crystal growth.
FIG. 4 shows a prior art having the above advantages of the prior arts shown in FIGS. 1 and 2. This prior art is disclosed in Japanese Patent Disclosure No. 61-191082. In this prior art, the thickness of the n.sup.- -InP layer 6 is slightly increased, and the central light detection region portion is removed by etching or ion milling to obtain a smooth profile. Thereafter, a moderately graded junction is formed. The guard ring 8 providing the moderately graded junction is formed in the front peripheral portion of the steeply graded junction. In the structure according to this prior art, the n.sup.- -InP layer obtained by regrowth is not required, and the diffusion depth of the steeply graded junction may be relatively small. Therefore, the above problems are not posed. However, in such a prior art, the extremely high-precision controllability of etching or ion milling is required, so that the manufacturing yield becomes low.

Method of manufacturing a semiconductor light detector


In video/audio information such as a movie in a mobile terminal connected to a terminal of a seat terminal for a mobile terminal, the video is converted into video data and transmitted to a seat terminal of a front seat via a transmission path. The video data are decoded by a video decoder of the seat terminal of the front seat and displayed on a video display section. Furthermore, audio is listened to by a user via a headphone of the user's own seat.

Recently, in passenger vehicles such as an aircraft, various in-flight services are provided to passengers by an in-flight entertainment system called IFE (In-Flight Entertainment), which is installed and disposed in an aircraft or in a cabin. When passengers use such in-flight services, for example, the passengers can view and listen to distributed movies or music by using a video display section of a liquid crystal display device or a headphone handed out when they board the aircraft. Furthermore, similarly, by using an operating terminal called a handset provided in each seat, passengers can play a game, make a phone call to the outside of the aircraft, and receive connection services to the Internet (see, for example, Patent Documents 1 and 2). Such services are transmitted as digital data via a network transmission path from an AV server set in an aircraft to a seat terminal (IFE) provided in each seat.
Hereinafter, a conventional AV content view system in an aircraft is described with reference to FIG. 5. FIG. 5 is a view showing an entire configuration of conventional AV content view system 200.
In AV content view system 200, network transmission path 2 is laid out along a plurality of seats 1m and 1n. Network transmission path (hereinafter, referred to as "transmission path") 2 is connected to AV server 3. AV server 3 provides AV content including video and audio content, for example, movies and games. Furthermore, AV server 3 can provide flight information and the like, if necessary.
Transmission path 2 is made of Ethernet (trade mark) cable. To transmission path 2, seat terminals 14m and 14n are connected for each seat. Furthermore, video display section 6m, 6n such as a liquid crystal display is set on the back part of each seat, and controller 5m, 5n and headphone 7m, 7n are connected to the front part of the seat. These devices are connected communicably to the above-mentioned AV server 3 via seat terminals 14m and 14n.
Furthermore, microphone 8a in crew's cabin 8 is connected to transmission path 2 via IP (Internet Protocol) adaptor 8b configured to convert an analog audio signal into a digital audio packet and to connect it to the Ethernet (trade mark).
A microphone similar to microphone 8a is equipped in a cockpit (not shown), and cabin attendants and an airline captain make an in-flight announcement to passengers by using the microphone.
In such a configuration, when, for example, a passenger seated in seat 1m selects a movie which he/she wants to watch by operating controller 5m, video and audio of the movie are downloaded and stored in seat terminal 14n of seat 1n in front of the passenger from AV server 3 (a plurality of pieces of content may be stored in a seat terminal in advance).
Video of a movie selected by a passenger is displayed on video display section 6n of front seat 1n, and audio is transmitted as digital data (audio packet) to seat terminal 14m behind seat terminal 14n via transmission path 2 and demodulated into an original analog audio signal in seat terminal 14m. A passenger can listen to the analog audio by headphone 7m.
The above-mentioned in-flight announcement from cabin attendants or an airline captain can be listened to by headphone 7m via seat terminal 14m of seat 1m. The in-flight announcement can be also listened to from a loudspeaker provided on the ceiling. However, a passenger using headphone 7m for a movie and the like cannot listen to the announcement from the loudspeaker. Therefore, the in-flight announcement is transmitted to seat terminal 14m via transmission path 2, and the audio of the movie is automatically switched to the in-flight announcement in the seat terminal, so that the in-flight announcement can be listened to by head phone 7m.
However, with the above-mentioned conventional AV content view system in an aircraft, passengers can receive only services of the AV content contained in AV server 3. Since there is a limit to the containing capacity of AV server 3, passengers using AV services repeatedly do not have content to be appreciated, or some passengers may not interested in the content.
Recently, portable terminals with which users can enjoy video and audio outside or in a mobile unit are being popularized. In a storage section (a hard disk or a semiconductor memory) of such a portable terminal, compressed data of AV content have been stored in advance. For example, users carry their portable terminals to the outside after they downloaded desired AV content into their portable terminals from PC and the like.
When passengers use such portable terminals in an aircraft, since the passengers use headphones attached to the portable terminals, they may miss in-flight announcement. Furthermore, although a large liquid crystal display for viewing AV services is equipped in front of the passengers, the passengers cannot use such a display and inconveniently watch video in a small screen of the portable terminal.    [Patent Document 1] Japanese Patent Application Unexamined Publication No. H7-143083    [Patent Document 2] Japanese Patent Application Unexamined Publication No. 2006-246297


The invention provides new call admission control methods for application in wireless networks such as wireless mesh networks. A separate set of call admission control constraints is applied to access links used to access the network and transit links between network nodes of the network. Both sets of constraints must be satisfied for a call to be accepted.

Call admission control (CAC) is employed in wireless networks to make decisions on whether or not to admit a new call. Such decisions are necessary in order to make sure there is capacity for the new call, and to determine if admitting the new call will have a negative effect on existing calls.
In existing call admission control mechanisms, the assumption is typically made that the capacity that limits call admission is that of the access links, and that so long as there is capacity on the access link, the backhaul network will have sufficient capacity.

Call admission control systems and methods for wireless networks


A bathing unit which includes a vertically adjustable bottom portion and fluid receiving channels. The lift mechanism includes a spring and manual spring tension adjuster. The user is able to adjust the spring so that the platform moves when the weight of the user plus the weight of the water in the channels is greater or less than the preset spring force.

Most people can get into or out of a bathtub with little difficulty. However, for a person that is physically handicapped or of advanced age, entry or exit from a bathtub can be very difficult. Furthermore, the smooth tub surface provides few handholds and can become quite slippery when it is wet. Therefore, current tub designs do not provide the safety or convenience that is required by many people.
A number of bathtub modifications and devices are available to help alleviate the above noted problems and difficulties. The most simple of these is the addition of handrails to the sides of the tub and the adjacent walls. This however, does not adequately help those individuals whose arms are somewhat weak due to advanced age or to some handicap.
A number of prior art inventions have been made in the field of movable tub platforms. These platforms either comprise the tub bottom or rest atop the tub bottom and function to temporarily reduce the height difference between the top of the tub's walls and the tub's bottom. Basically, the prior art movable tub platforms are modified commercial type lifts which the user controls with a manual switch. These devices require an external electric or hydraulic power source and can be quite complicated to install, operate or maintain. They operate in a manner which is completely independent of the tub conditions and therefore do not take advantage of the user's weight or the weight of any water within the tub.

Bathing unit with adjustable height platform