An athermal AWG module 10 comprises: an AWG 11 having waveguides partially divided to separate a chip, separated chips being connected by a compensation plate 33 to achieve temperature-independence; an athermal AWG chip 12 having a substrate and the AWG 11 formed on the substrate; a package 13 having an opening 14 and accommodating the athermal AWG chip 12; and a cover for blocking the opening 14. The athermal AWG chip 12 is fully covered with a gelled refractive index matching agent 16 that is matched in refractive index to the waveguides of the AWG 11. As the gelled refractive index matching agent 16 is excellent in water resistance and hardly passes water, the adhesive agent for fixing the compensation plate 33 to the surfaces of the separated two chips is prevented from being deteriorated due to ingress of water, thereby enhancing the reliability.

1. Technical Field
The present invention relates to an athermal AWG module used as an optical multiplexer/demultiplexer, for example, in wavelength division multiplexing optical communications, which module is unaffected by the temperature, that is, athermal.
2. Related Arts
In an arrayed waveguide grating (AWG)-type optical multiplexer/demultiplexer that handles the function of an optical multiplexer/demultiplexer, the center wavelength (transmission center wavelength) is dependent on the temperature due to temperature dependence of the refractive index of the silica glass. In order to cancel its temperature dependence, Japanese Patent Laid-open Publication No. 2006-284632 discloses an AWG-type optical multiplexer/demultiplexer in which waveguides are partially cut to separate a chip and separated chips are connected with a compensation plate to achieve athermalization (temperature-independence).
By the way, in the case of manufacturing an athermal AWG module by accommodating the conventional AWG chip as disclosed in the above-mentioned JP 2006-284632 into a package, there is a problem that an adhesive agent for fixing the compensation plate to the separated chips is deteriorated by penetration of water and the center wavelength fluctuates. Further, as the waveguides are cut partially, there is a need to fill matching oil that is matched in refractive index to the waveguides, and any contrivance needs to be made for the package to prevent leakage of the oil. In order to solve these problems, there is contemplated an athermal AWG module that adopts a hermetic structure in which a cover for blocking an opening of the package is secured to the package by welding. The inner structure of this athermal AWG module is illustrated in FIG. 10 and the module in which the cover is closed for blocking the opening is illustrated in FIG. 11. This athermal AWG module 100 has an athermal AWG chip 120 as disclosed in the above-mentioned JP 2006-284632, a package 130 for accommodating the chip and a cover 150 blocking an opening 140 of the package 130. In the athermal AWG chip 120, an AWG 110 having partially cut waveguides is formed on a substrate. This athermal AWG chip 120 is divided into two by a crossing separation surface 300 and a noncrossing separation surface 310 and the separated chips are connected with the compensation plate 330. Then, in this athermal AWG module 100, matching oil is injected through an oil inlet (not shown) into the package 130 hermetically sealed by welding.
However, in this athermal AWG module 100, there are problems of high cost and larger module size for required welding margin. In other words, as there is local temperature increase in the welded part 160 during welding and the temperature of the chip also increases, there is a need to provide a predetermined distance A between the welded part 160 and the athermal AWG chip 120. This results in the problems that the module size becomes larger. Besides, as the welding operation has to be done, the cost becomes higher.
The present invention has been made in view of the conventional problems, and it is an object of the present invention to provide an athermal AWG module that is low in cost and small sized and has high reliability.


A glass container body check detector is disclosed which comprises a conveyor for conveying glass containers in a predetermined direction to an inspection station, a rotator for rotating a glass container at the inspection station about the axis of the glass container, and an inspection assembly for detecting a check in the body of the rotating glass container. The inspection assembly includes a diffuse light source for directing diffused light at the sidewall of the rotating glass container in a direction perpendicular to the predetermined direction of conveyance of the glass container, a pair of angularly related directed light sources located above the rotating container for focusing light through the container into coincident vertical lines of light on the sidewall of the container, from the top of the bottle to the bottom of the container, and a linear array camera located above the rotating glass container and focused on the coincident lines of directed light.

In the standard process for making glass containers, certain defects occur due to various process variances. Among these defects, checks are a common type of defect. A check is a crack in the glass that causes a structural flaw in the container. This flaw will likely lead to the container's failure during or after filling. Checks can occur in almost any location on the container. Checks in the finish area and the heel area are detected using several methods. The primary method is to use a directed light source on a specific location on the bottle. A light sensitive sensor is placed such that the check or crack will reflect the directed light into that sensor. Since finish and heel checks occur in repeatable, expected locations, this method works reliably.
Checks that occur in the sidewall area (body) of the container are less repeatable. The process variance that produces such a check, does not cause the check to occur in a repeatable expected location. These checks tend to be large cracks that are curved in shape. They can also be located anywhere on the sidewall of the container.
U.S. Pat. Nos. numbered 3,245,533, 4,399,357 and 4,664,525, disclose check detecting systems.


A fluid filled watch includes a housing having a transparent housing lens, with watch hands mounted within a cavity of the watch containing a chemiluscent fluid. The fluid is arranged to provide for visual highlights within the watch during conditions of limited available light.

1. Field of the Invention
The field of invention relates to watch apparatus, and more particularly pertains to a new and improved fluid filled watch apparatus wherein the same is arranged to incorporate a chemiluscent fluid within the watch housing for visual amusement, entertainment, and ease of ascertainment of available time.
2. Description of the Prior Art
Watch structure of various types have been utilized throughout the prior art such as indicated in U.S. Pat. Nos. 4,945,523; 4,779,249; 4,028,377; and 3,635,402.
The instant invention attempts to overcome deficiencies of the prior art by providing for a watch containing a chemiluscent fluid for ease of ascertaining of available time and entertainment and amusement of individuals and in this respect, the present invention substantially fulfills this need.


A semiconductor photodetector element includes a semiconductor substrate having a first conductivity type; a columnar structure formed on a first surface of the semiconductor substrate, the columnar structure being composed of a semiconductor of the first conductivity type; a light absorption layer formed so as to surround the columnar structure; and a semiconductor layer formed so as to surround the light absorption layer.

Demand for compact and high performance semiconductor photodetector elements continues to increase for the purpose of downsizing and high density integration of imaging arrays. As a semiconductor photodetector element, a semiconductor surface-photodetector element is generally known. Such a semiconductor photodetector element includes a light absorption layer and a conductive layer stacked in layers in a plane of a substrate to receive light incident perpendicular to a film surface.

Semiconductor photodetector element and method


A phased array sector scanning ultrasonic imaging system includes a transducer array with 2N separate transducer elements and a transmitter and receiver with N separate channels. The complete 2N element aperture is realized at each beam angle with two firings of the transmitter and the receipt of echo signals from two different sets of N transducer elements. The echo signals from the two firings are coherently summed to form a single receive beam. Two different patterns are provided for selecting which transducer elements to energize and receive from during each of the two firings.

This invention relates to imaging by use of vibratory energy such as acoustical energy and, in particular, to phased array sector scanners employed in medical imaging.
There are a number of modes in which vibratory energy, such as ultrasound can be used to produce images of objects. The ultrasound transmitter may be placed on one side of the object and the sound transmitted through the object to the ultrasound receiver placed on the other side ("transmission mode"). With transmission mode methods, an image may be produced in which the brightness of each pixel is a function of amplitude of the ultrasound that reaches the receiver ("attenuation" mode), or the brightness of each pixel is a function of the time required for the sound to reach the receiver ("time-of-flight" or "speed of sound" mode). In the alternative, the receiver may be positioned on the same side of the object as the transmitter and an image may be produced in which brightness of each pixel is a function of amplitude of the ultrasound reflected from the object back to the receiver ("refraction", "backscatter" or "echo" mode). The present invention relates to a backscatter method for producing ultrasound images.
There are a number of well known backscatter methods for acquiring ultrasound data. In the so-called "A-scan" method, an ultrasound pulse is directed into the object by the transducer and the amplitude of the reflected sound is recorded over a period of time. The echo signal amplitude is proportional to the scattering strength of the reflectors in the object and the time delay is proportional to the range of the reflectors from the transducer. In the so-called "B-scan" method, the transducer transmits a series of ultrasonic pulses as it is scanned across the object along a single axis of motion. The resulting echo signals are recorded as with the A-scan method and their amplitude is used to modulate the brightness of pixels on a display at the time delay. With the B-scan method, enough data are acquired from which an image of the reflectors can be reconstructed.
In the so-called C-scan method, the transducer is scanned across a plane above the object and only the echoes reflecting from the focal depth of the transducer are recorded. The sweep of the electron beam of a CRT display is synchronized to the scanning of the transducer so that the x and y coordinates of the transducer correspond to the x and y coordinates of the image.
Ultrasonic transducers for medical applications are constructed from one or more piezoelectric elements sandwiched between a pair of electrodes. Such piezoelectric elements are typically constructed of lead zirconate titanate (PZT), polyvinylidene difluoride (PVDF), or PZT ceramic/polymer composite. The electrodes are connected to a voltage source, and when a voltage waveform is applied, the piezoelectric elements change in size at a frequency corresponding to that of the applied voltage. When a voltage waveform is applied, the piezoelectric element emits an ultrasonic wave into the media to which it is coupled at the frequencies contained in the excitation waveform. Conversely, when an ultrasonic wave strikes the piezoelectric element, the element produces a corresponding voltage across its electrodes. Typically, the front of the element is covered with an acoustic matching layer that improves the coupling with the media in which the ultrasonic waves propagate. In addition, a backing material is coupled to the rear of the piezoelectric element to absorb ultrasonic waves that emerge from the back side of the element so that they do not interfere. A number of such ultrasonic transducer constructions are disclosed in U.S. Pat. Nos. 4,217,684; 4,425,525; 4,441,503; 4,470,305 and 4,569,231, all of which are assigned to the instant assignee.
When used for ultrasound imaging, the transducer typically has a number of separate piezoelectric elements arranged in an array and driven with separate voltages (apodizing). By controlling the time delay (or phase) and amplitude of the applied voltages, the ultrasonic waves produced by the piezoelectric elements (transmission mode) combine to produce a net ultrasonic wave that travels along a preferred beam direction and is focused at a selected point along the beam. By controlling the time delay and amplitude of the applied voltages, the beam with its focal point can be moved in a plane to scan the subject.
The same principles apply when the transducer is employed to receive the reflected sound (receiver mode). That is, the voltages produced at the transducer elements in the array are summed together such that the net signal is indicative of the sound reflected from a single focal point in the subject. As with the transmission mode, this focused reception of the ultrasonic energy is achieved by imparting separate time delay (and/or phase shifts) and gains to the signal from each transducer array element. These functions require a separate channel for processing the signal from each transducer element.
This form of ultrasonic imaging is referred to as "phased array sector scanning", or "PASS". Such a scan is comprised of a series of measurements in which the steered ultrasonic wave is transmitted, the system switches to receive mode after a short time interval, and the reflected ultrasonic wave is received and stored. Typically, the transmission and reception are steered in the same direction (.theta.) during each measurement to acquire data from a series of points along an acoustic beam or scan line. The receiver is dynamically focused at a succession of ranges (R) along the scan line as the reflected ultrasonic waves are received. The time required to conduct the entire scan is a function of the time required to make each measurement and the number of measurements required to cover the entire region of interest at the desired resolution and signal-to-noise ratio. For example, a total of 128 scan lines may be acquired over a 90 degree sector, with each scan line being steered in increments of 0.70.degree.. A number of such ultrasonic imaging systems are disclosed in U.S. Pat. Nos. 4,155,258; 4,155,260; 4,154,113; 4,155,259; 4,180,790; 4,470,303; 4,662,223; 4,669,314 and 4,809,184, all of which are assigned to the instant assignee.
The quality of image produced using the PASS method is in part determined by the number of separate transducer elements employed in the array. By increasing the number of array elements, the aperture is increased, resulting in a finer speckle structure and improved resolution.
The number of array elements used in a PASS system is, however, usually limited by commercial considerations. Not only does the size of the transducer array increase as the number of separate elements increases, but more significantly, the additional transmit and receive channels required for beam forming increases the hardware requirements and system complexity. A state-of-the art commercially available PASS ultrasonic imaging system, for example, may have 128 separate transducer elements and a corresponding number of transmit and receive channels, but to double this number would drive the size and complexity of the system upward. The increased size and complexity of the system, moreover, would tend to make it not price competitive.
One approach which enables the number of array elements to be increased without a corresponding increase in the transmit and receive channels is to multiplex the transducer elements with the available transmit/receive channels. In this method wherein the transducer array elements are 2N in number, the central array elements, N in number, are driven by the corresponding N transmit channels during a first firing at each beam angle in the scan and the N receive channels are switched to receive the signals from the N odd numbered array elements in the 2N array. This is followed by a second firing at the same beam angle using the central N array elements. The N receive channels are switched to receive the signals from the N even numbered array elements and the received signals are summed with the signals from the first firing. While this approach effectively doubles the number of receive array elements with a consequent improvement in image quality, it is not without cost. In addition to doubling the scan time, a separate multiplexer is needed for each of the N receive channels and a separate transmit/receive switch is required for each of the 2N array elements.

Phased array sector scanner with multiplexed acoustic transducer elements


Alternative methods of constructing a vertically offset structure are disclosed. An embodiment includes forming a flexible layer having first and second end portions, an intermediate portion coupling the first and second portions, and upper and lower surfaces. The distance between the upper and lower surfaces at the intermediate portion is less than the distance between the upper and lower surfaces at the first and second end portions. The first end portion is bonded to a base member. The second end portion of the flexible layer is deflected until the second end portion contacts the base member. The second end portion is bonded to the base member.

Vertically offset silicon structures for use in microelectromechanical systems (MEMS) or microsystem technology (MST) or nanotechnology can be created by, employing a voltage V, anodically bonding a silicon structure 5 to an etched glass wafer 10 (FIG. 1-1), removing the handle material from the silicon, and then pushing parts of the silicon into contact with the glass while performing a second anodic bond using the voltage V (FIG. 1-2). During formation of this second bond, the silicon 5 is pulled down to the glass 10, and high stresses can develop near the anchor of the push-down structure where the first anodic bond took place. These stresses can cause fracture in the silicon push-down structure 5 or otherwise have a negative impact on the performance of the mechanism.

Mitigation of high stress areas in vertically offset structures


A process for extracting the water soluble fiber from corn fiber hulls is provided comprising the steps of subjecting the corn fiber hulls to a destarching process, a dewatering process, and exposing the destarched and dewatered corn fiber hulls to a thermochemical treatment to obtain a water-soluble non-caloric corn fiber. A water-soluble non-caloric corn fiber composition is disclosed comprising a destarched corn fiber hull produced by subjecting corn fiber hulls to a non-alkaline destarching process to obtain a destarched corn fiber, dewatering said destarched corn fiber hull, and exposing said destarched and dewatered corn fiber hull to one or more thermochemical treatments to obtain a water-soluble non-caloric corn fiber. Foods and a pharmaceutical comprising the water-soluble non-caloric corn fiber composition are disclosed.

1. Field of the Invention
This application relates to the commercial processing of corn fiber hulls, and, in particular, to the production of a water soluble corn fiber composition. The water soluble corn fiber composition may be used in food applications as a non-caloric additive or filler or may be used for non-food uses.
2. Description of the Background Art
The water soluble fiber extract from the hulls of corn kernels can serve as a non-caloric additive for food and non-food uses. Methods of extracting the hemicellulosic portion of the corn fiber are well known in the prior art. In particular, well known prior art methods utilize a multi-step process starting with an alkaline extraction of the corn fiber hemicellulose gum fraction as a whole. The processing of the corn fiber by alkaline extraction utilizes hydrogen peroxide, alkali, protease enzyme, and/or solvents to extract the hemicellulose gum. These methods are expensive because of the multiple steps and materials needed. Therefore, it is desirable to develop an economical process utilizing fewer steps and materials.
U.S. Pat. No. 4,038,481 discloses a method of treating corn hulls with alkali to hydrolyze the corn hulls to effect liberation of the hemicellulose fraction.
U.S. Pat. No. 4,957,599 discloses a process for converting nonwoody lignocellulosic substrates into products digestible by ruminants and ingestible by humans by forming a slurry of the substrate with an aqueous alkali for wetting of the substrate and subsequently forming a slurry of the wetted substrate in an alkaline peroxide solution to expose the hemicellulose.
U.S. Pat. No. 5,264,568 discloses a process for preparing a pyrodextrin comprising heating starch in the presence of hydrochloric acid, dissolving the pyrodextrin in water, adjusting the aqueous solution of the pyrodextrin to a pH of from 7.0 to 8.5, pre-hydrolyzing the pH adjusted solution with alpha-amylase produced by Bacillus licheniformis to obtain a hydrolysate, adjusting the hydrolysate to a pH of from 5.5 to 6.5, hydrolyzing the pH adjusted hydrolysate with alpha-amylase, adjusting the hydrolysate to a pH of 4.0 to 5.0, autoclaving the resulting hydrolysate, hydrolyzing the autoclaved hydrolysate with the alpha-amylase, adjusting the hydrolysate to a pH of 4 to 5, and autoclaving the resulting hydrolysate.
U.S. Pat. No. 5,430,141 discloses a process of preparing low calorie dextrin comprising the steps of heating corn starch in the presence of mineral acid to prepare pyrodextrin, hydrolyzing the pyrodextrin with alpha-amylase, adding an organic solvent such as ethanol to the hydrolyzed pyrodextrin and recovering low calorie pyrodextrin from the solvent.
U.S. Pat. No. 6,147,206 discloses a process for the preparation of corn fiber gum comprising mixing corn fiber with an alkaline solution to form a slurry and extract hemicellulose, treating the slurry with hydrogen peroxide at a pH of 10 to 12.5, and separating out the insoluble fractions from the corn fiber slurry to yield corn fiber gum in solution.
In spite of this background art, there remains a very real and substantial need for an economical process for extracting the water-soluble portion of corn fiber hulls to yield a water-soluble non-caloric corn fiber that is useful as an additive to animal feed, ingestible for human food consumption, and for non-food uses such as an ingredient or filler in a pharmaceutical composition.

Soluble non-caloric fiber composition and process of preparing the same


A wire basket includes a storage portion and base portion removably connected together and providing sliding operation. End caps connected to the storage portion are configured to allow for the removable connection. Glide members having a curved portion and connected to the base portion are configured to allow for the sliding operation.

Storage devices, such as bins and baskets are often slidably mounted to allow better access to the interior for depositing and removing material. This sliding mounting is typically accomplished using wheels that are aligned with rails or other guiding mechanisms to provide such movement over a predetermined distance (e.g., forward and backward between stops provided on the ends of the rails). These wheels are prone to breakage and failure. It is difficult, particularly for consumers, to repair or replace these wheels, and thus users either must tolerate less than optimum performance, or spend the time and effort to replace the entire storage device.
Another shortcoming of many sliding storage devices is that their construction does not provide complete access to the interior. Still another shortcoming is that it can be difficult to remove the storage device from its sliding mounting, at least without disturbing the contents of the storage device.

This patent is subject to a terminal disclaimer.


An attachment device for anchoring a medical device to a patient has, in one aspect, an anchoring portion for attachment to the tissue of a patient by operation of at least one piercing member which in use is deployed for anchoring the device to the tissue of a patient. Alternatively, or additionally, in a further aspect an attachment device comprises a holding part, for holding an elongate object, which is operable between an open position which allows removal of the elongate object and a closed position adapted to securely retain the elongate object. The holding part may include first and second holding portions, for respectively engaging first and second surface parts of the elongate object.

For many medical applications it is important that tubes, such as catheter or surgical drain tubes, are securely attached relative to a patient. The consequences of accidental movement of such a tube can range from discomfort (for example in the case of small peripheral vein catheters) to fatal trauma (for example in the case of main line catheters).
A typical method used to secure a catheter is to use a plastic base which includes two apertures and a holding clip for a catheter tube and to sew or suture the base to the patient, using a needle and thread by passing the needle through the apertures and through the skin and/or other tissue of the patient. This is a relatively complex and time consuming operation and is prone to error. For example the thread may be sewn too tight, causing unnecessary tissue damage or too loose, resulting in an inadequately secured catheter. Furthermore, there is a significant risk of needle stick injuries, which are a serious health hazard due to the widespread existence of diseases which are transmissible via bodily fluids.
One approach to avoiding needle stick injuries has been to dispense with the use of sutures and to secure a base of an attachment device to the skin of a patient using an adhesive. However, this approach does have accompanying disadvantages. The adhesive may inadequately fix the catheter, or be effective for only an inadequately short time. Hair on the skin and/or occurrence of perspiration may result in a significant loss of adhesion, or the adhesive may suffer from reduced adhesion over time due to oils excreted by the skin, or other factors. The adhesive may intrinsically provide inadequate adhesion. If a very strong adhesive is used, removal of the attachment device may result in tearing the skin. The adhesive may provoke an irritant and/or allergic reaction as may a cleaning agent (typically benzoin or tinc benz) used to clean the skin prior to application of the adhesive.
Known attachment devices have employed various means for securing the medical tube to the attachment device, but at least some such means are less than optimally convenient in use. For example, some such devices do not allow convenient attachment and release of the tube when the attachment device is securely attached to the patient, and some require the use of separate elements which must be attached to the tube prior to securing the tube to the main part of the attachment device.
There is therefore a need for an improved, or at least alternative, attachment device and method for use in securing catheter tubes and/or other medical devices to a patient.


Channel based authentication schemes for intrusion detection that operates at the physical layer are described that apply the capabilities of a pattern re-configurable antenna for improved performance. Performance gains are achieved by the schemes as a function of the number of antenna modes. The first scheme relies on a channel based fingerprint for differentiating between transmitters whereas another scheme poses the intruder detection problem as a generalized likelihood ratio (GLR) test problem that operates on the channel realizations corresponding to different modes present in a reconfigurable antenna. The benefits of these two schemes over single element antennas are demonstrated. General guidelines are provided on how to choose the different elements of the decision metric in order to realize better performance for physical layer based authentication schemes based on any diversity scheme.

Large scale proliferation of wireless technology coupled with the increasingly hostile information security landscape is of serious concern. The fundamental broadcast nature of wireless data transmission aggravates the situation since unlike wired networks it introduces multiple avenues for attack and penetration into a network. Attacks on wireless networks have become increasingly sophisticated with the increasing pervasiveness of these networks. It is challenging to detect and counteract intrusions in wireless networks due to the inherent broadcast nature of the medium. Currently known security risks include denial of service attacks, man-in-the-middle attacks, MAC address spoofing attacks, client-to-client attacks, network injection and brute force attacks against access point passwords. Man-in-the-middle attacks and spoofing attacks pose a particularly significant intrusion threat to wireless networks since such attacks allow intruders to hijack a connection already established by a legitimate user. These risks will continue to increase in number and sophistication as wireless networks start to carry increasingly more sensitive information.
Though advanced wireless intrusion protection and detection systems have been developed and deployed to mitigate such threats, it has been repeatedly demonstrated that each method has its point of failure and no single method guarantees protection against all attacks. See, e.g., W. A. Arbaugh, N. R. Shankar and Y. C. Justin Wan, "Your 802.11 Wireless Network has No Clothes," IEEE Wireless Communications, pages 44-51, 2001; N. Borisov, I. Goldberg, and D. Wagner, "Intercepting mobile communications: the insecurity of 802.11," MobiCom '01: Proceedings of the 7th annual international conference on Mobile computing and networking, pages 180-189, New York, N.Y., USA, 2001: ACM. Also, while several established protection mechanisms such as cryptography based techniques and wireless intrusion prevention systems exist, each method has its own weaknesses and is susceptible to failure under different circumstances. The resulting uncertainties have led to a significant paradigm shift in the design and implementation of wireless security in recent times, where an increasingly cross-layer approach is being pursued to protect wireless networks. One such avenue for security has been to use the physical layer information to protect against intruders and attackers. Especially channel information available at the physical layer is being increasingly used to provide an additional degree of protection against intruders. The idea of using physical layer information to enhance security has been approached under two broad categories. The first category of work focuses on cryptography based techniques that utilize physical layer information to generate and share keys. See, e.g., B. Azimi-Sadjadi, A. Kiayias, A. Mercado, and B. Yener, "Robust key generation from signal envelopes in wireless networks," in CCS '07: Proceedings of the 14th ACM conference on Computer and communications security. New York, N.Y., USA: ACM, 2007, pp. 401-410; J. E. Hershey, A. A. Hassan, and R. Yarlagadda, "Unconventional cryptographic keying variable management," Communications, IEEE Transactions on, 43(1):3-6, 1995; S. Jana, S. N. Premnath, M. Clark, S. K. Kasera, N. Patwari, and S. V. Krishnamurthy, "On the effectiveness of secret key extraction from wireless signal strength in real environments," in Proceedings of the 15th annual international conference on Mobile computing and networking. New York, N.Y., USA: ACM, 2009, pp. 321-332; and H. Kitaura, A. Sasaoka, "A scheme of private key agreement based on the channel characteristics in OFDM land mobile radio," Electronics and Communications in Japan Part 3: Fundamental Electronic Science, vol. 88, no. 9, pp. 1-10, 2005; N. Patwari, J. Croft, S. Jana, and S. K. Kasera, "High-Rate Uncorrelated Bit Extraction for Shared Secret Key Generation from Channel Measurements. IEEE Transactions on Mobile Computing, 9:17-30, 2009; and S. Yasukawa, H. Iwai, and H. Sasaoka, "Adaptive key generation in secret key agreement scheme based on the channel characteristics in OFDM," Information Theory and Its Applications, 2008, ISITA 2008, International Symposium on, pages 1-6, 2008. In the second approach, some form of the physical layer information associated with a device, such as channel frequency response or RSSI, is used as an identifier to differentiate between different devices and thus provide a mechanism for authentication. See e.g., M. Demirbas and Y. Song, "An RSSI-based Scheme for Sybil Attack Detection in Wireless Sensor Networks," WOWMOM '06: Proceedings of the 2006 International Symposium on World of Wireless, Mobile and Multimedia Networks, pages 564-570, Washington, D.C., USA, 2006, IEEE Computer Society; D. B. Faria and D. R. Cheriton, "Detecting identity-based attacks in wireless networks using signal prints," in WiSe '06: Proceedings of the 5th ACM workshop on Wireless security. New York, N.Y., USA: ACM, 2006, pp. 43-52; N. Patwari and S. K. Kasera, "Robust location distinction using temporal link signatures," in MobiCom '07: Proceedings of the 13th annual ACM international conference on Mobile computing and networking. New York, N.Y., USA: ACM, 2007, pp. 111-122; L. Xiao, L. Greenstein, N. Mandayam, and W. Trappe, "Fingerprints in the ether: Using the physical layer for wireless authentication," in Communications, 2007. ICC '07. IEEE International Conference on, June 2007, pp. 4646-4651; L. Xiao, L. Greenstein, N. Mandayam, and W. Trappe, "Using the physical layer for wireless authentication in time-variant channels," Wireless Communications, IEEE Transactions on, 7(7):2571-2579, 2008; and "Channel-based spoofing detection in frequency-selective Rayleigh channels," Wireless Communications, IEEE Transactions on, vol. 8, no. 12, pp. 5948-5956, 2009.
Intrusion detection has traditionally been categorized into misuse detection or anomaly detection techniques. While the former uses patterns characteristic of known attacks to detect known intrusions, the latter relies on detecting deviations from the established behavior patterns in the system. Y. Zhang and W. Lee, "Intrusion detection in wireless ad-hoc networks," Proceedings of the 6th annual international conference on Mobile computing and networking in MobiCom '00, pages 275-283, New York, N.Y., USA, 2000, ACM. In many usage scenarios, where the physical link remains unchanged over a session, the wireless channel response corresponding to the link can be considered to represent the established behavior pattern for that link. Any changes that violate this pattern abruptly beyond a certain limit can be then checked for adversarial behavior.
In parallel to these developments, significant progress has been made in the design of reconfigurable antennas resulting in numerous designs that are reconfigurable in frequency, pattern, polarization or a combination of these parameters. For many new and emerging high data rate applications, pattern reconfigurable antennas are of special interest due to their ability to generate highly uncorrelated radiation patterns that can produce uncorrelated channel realizations in a multi-path rich wireless medium for a given frequency. See, e.g., A. Forenza and J. Heath, R. W., "Benefit of pattern diversity via two-element array of circular patch antennas in indoor clustered MIMO channels," Communications, IEEE Transactions on, vol. 54, no. 5, pp. 943-954, May 2006. The ability of pattern reconfigurable antennas to enhance system throughput has been well demonstrated by D. Piazza, P. Mookiah, M. D'Amico, and K. R. Dandekar, "Experimental Analysis of Pattern and Polarization Reconfigurable Circular Patch Antennas for MIMO Systems, Vehicular Technology, IEEE Transactions on, 59(5):2352-2362, 2010. Such antennas have gained widespread attention due to their ability to improve throughput and are gradually finding their way into commercial wireless systems. The uncorrelated nature of the channel realizations due to such an antenna are believed by the inventors to hold great potential to enhance physical layer based security schemes.
Previous works that explored the idea of physical layer information based authentication are based on the use of conventional antennas. It is desired to demonstrate how the capabilities of reconfigurable antennas to generate decorrelated channels can be used to enhance physical layer information based device authentication schemes for wireless systems. However, it should be noted that the security scheme described herein is not meant to be a replacement for existing higher layer security algorithms. Instead, it is desired to leverage the capabilities of reconfigurable antennas to provide an additional layer of security for wireless systems. Moreover, it is also desired to develop a general guideline on how to choose the different elements of the decision metric in order to realize better performance for physical layer based authentication schemes based on any diversity scheme.
The problem that is addressed by the invention is one of establishing the identity of a transmitting device in a wireless network. Spoofing attacks in network security encompasses a wide range of attacks that are based on one entity deceiving another to accept the attacking entity's identity to be something else. Many variants of this attack rely on the attacker monitoring the packet flow between the victims to obtain some sensitive information that identifies one or both of the victims. Information obtained thus serves as the launching pad for more sophisticated attacks. Due to the unbounded nature of the medium employed, such information can be obtained easily in a wireless network making them especially vulnerable to such attacks. Hence, an additional mechanism for protection at the physical layer that can detect intrusion and thwart such attacks can significantly enhance the security of a wireless network. The present invention addresses these needs in the art.

Reconfigurable antenna based solutions for device authentication and intrusion detection in wireless networks


A method for hot forging at least one end of a steel reinforcing bar (i.e., a rebar) to simultaneously form a wide head and threads funning around the head during a single step whereby to enable the bar to be coupled end-to-end an adjacent steel bar to be used, for example, to reinforce a precast concrete structure. The end of the bar is first preheated, and the heated end is surrounded by a closing die having a threaded geometry. The die is then nested within and closed around the heated end by an annulus ring of a hydraulic press, or the like. A hydraulic ram of the press is moved through the annulus ring and into engagement with the heated end of the rod so as to apply a compressive force thereto. The metal of the heated end flows into the die so as to be enlarged therein and assume the threaded geometry of the die.

1. Field of the Invention
The invention relates to a method for hot forging at least one end of a steel reinforcing bar (commonly referred to as a rebar), or the like, so as to form an enlarged threaded head during a single step. The threaded head of the rebar is adapted to be connected to an opposing threaded rebar by means of a suitable threaded coupler to be used, for example, to reinforce a precast concrete structure.
2. Background Art
From time-to-time, it becomes necessary to connect one steel bar to another. By way of example, in the case of concrete construction or repair, a plurality of steel reinforcing bars are connected end-to-end to be embedded within a precast concrete structure to enhance the strength of the structure and enable the structure to avoid shifting relative to an adjacent structure and better withstand the effects of an earthquake and other natural forces. Opposite ends of a pair of axially-aligned rebars are connected together by means of a coupler located therebetween. In this case, the opposing ends of the rebars to be connected together are threaded during a cold working process by either rolling or cutting the threads into the bars. The threaded ends of the rebars are rotated into mating engagement with a correspondingly threaded coupler. To maximize the cross-sectional (i.e., tensile) property of the bars, the threaded end of each can be enlarged prior to threading by either one of an independent cold or hot forming or forging step. In this case, the bar is provided with a relatively wide upset head often known in the art as a button or mushroom head.
It would be desirable to combine the advantages of upsetting and threading one or both ends of a rebar or the like during an efficient one-step process so as to eliminate the need to perform the separate and time-consuming independent steps in the manner described above.

Method for hot forging threads into an end of a steel bar


An integrated circuit chip (IC) is equipped with a device for preventing reverse engineering by monitoring light emissions emitted from transistors and such electrically active devices in a circuit located in the IC. The device emits extraneous randomized light emissions in substantial close proximity to the transistors to hide a pattern of light emissions emitted from the transistors. As one feature, the device can include a source of randomized light emissions in substantial close proximity to the transistors to hide a pattern of the emitted light from the transistors in randomized light emissions emitted by the source. As a second feature, the device can emit the randomized light emissions by randomly delaying an electrical signal that is electrically coupled to the transistors and, in response to the randomly delayed electrical signal, the transistors randomly emitting light emissions thereby hiding a separate pattern of light emission emitted from the transistors.

1. Field of the Invention
This invention generally relates to reverse engineering of integrated circuits by optical monitoring and analysis, and more particularly to devices for defeating such reverse engineering of integrated circuits.
2. Description of the Prior Art
The term "reverse engineering" has the general meaning of understanding how any item operates or was constructed, based mainly on knowing the general function of the item and any information that can be learned by direct examination of the item itself. Reverse engineering is considered "non-destructive" if the item is still functional at the end of the reverse engineering process.
With regards to an integrated circuit (IC) made up from transistors, diodes, and passive devices, reverse engineering can be applied to either (i) determine the processes and materials that went into the IC manufacturing process, or (ii.a) determine the physical locations of the subcircuits or circuit elements comprising the IC, (ii.b) determine the logical functions and other functional characteristics of the subcircuits or circuit elements comprising the IC, (ii.c) determine the device-level schematic of the transistors comprising each subcircuit or circuit element, (ii.d) determine the performance of the subcircuits or circuit elements comprising the IC and (ii.e) determine stored information necessary for the operation of some circuit. In this disclosure, we are concerned with defeating certain of these second types of reverse engineering.
Conventional methods of reverse engineering are usually physical methods that are often destructive of an IC. Often these methods require unpackaging, and sometimes at least partially dissecting the IC, making it very difficult to use the IC afterwards. Further, these prior art methods typically involve significant manual intervention by technical personnel. Therefore, the methods can be tedious and inefficient. In addition, some kinds of information about circuits, such as the contents of non-volatile semiconductor memories often cannot be obtained by disassembly of the chip.
The least destructive, or non-destructive, methods for reverse engineering, such as looking at power consumption or looking at RF emissions from an IC, normally have limited or no spatial resolution. Therefore, they usually cannot provide information at the gate level about either the physical location of subcircuits of the chip or the device-level schematic of the transistors comprising each subcircuit. They cannot generate this kind of information in reverse engineering a circuit. They therefore make little use of information about the spatial layout of a chip that can be readily obtained by optical inspection. Reverse engineering a complex IC without spatial information about specific devices that are in close proximity to each other on the IC can be very difficult with these methods. Additionally, such conventional techniques are readily defeated by a number of simple countermeasures that are well known.
In view of the above mentioned problems with prior art methods of reverse engineering, the present inventors have taught methods for reverse engineering by monitoring induced light emissions from the active elements in integrated circuit (IC) chips in a co-pending patent application Ser. No. 09/468,999, entitled "Method And Apparatus For Reverse Engineering Integrated Circuits By Monitoring Optical Emission", filed on Dec. 21, 1999, by inventors Kash et al., and the teachings of which are incorporated herein by reference. Generally, light emissions from active elements can be monitored using methods and apparatus that have been taught in the following identified co-pending patent applications, the first one being numbered Ser. No. 08/683,837, entitled "Noninvasive optical method for measuring internal switching and other dynamic parameters of CMOS circuits", filed on Jul. 18, 1996, by inventors Kash et al., and the second one being numbered Ser. No. 09/026,063, entitled "System and method for compressing analyzing time-resolved optical data obtained from operating integrated circuits", filed on Feb. 19, 1998, by inventors Kash et al., and which are both owned by the assignee of the present invention, and the teachings of which are incorporated herein by reference.
The methods of reverse engineering integrated circuits by monitoring induced light emissions from the active elements in IC's, such as taught by the present inventors in co-pending patent application Ser. No. 09/468,999, are a very powerful tool for extracting information from an integrated circuit as well as for determining the circuit topology. A manufacturer of an integrated circuit, in certain applications, may wish to protect an integrated circuit from such reverse engineering analysis. For example, a SmartCard or other secure electronic device that contains at least one IC with confidential information may need its electronic memory protected from unauthorized reverse engineering.
The above optical methods of non-destructively obtaining information about the design, operation, programmable parameters, and performance of an integrated circuit represent one possible approach to reverse engineering an integrated circuit by combining the physical appearance of the circuit elements, and using the effect of the operation of the circuit on light. Other approaches producing similar information include the measurement of the modulation of a light beam by voltages in an IC.
Accordingly, the inventors of the present invention recognize a need for a manufacturer of an integrated circuit to efficiently limit the information provided by the generation and/or the detection of induced light emissions and/or the modulation of the optical response from the active elements in IC's to defeat such reverse engineering as discussed above.

Device for defeating reverse engineering of integrated circuits by optical means

International Business Machines Corporation


A battery pack includes a case, a first set of battery cells and a second set of battery cells received in the case, a circuit board, and a main power output interface. The first set of battery cells and the second set of battery cells can be connected in series or in parallel, and output two kinds of working voltage through the main power output interface. The battery pack further includes an extended power output interface and a switch provided between the first set of battery cells and the second set of battery cells. The battery pack can output a third voltage for an external device through the extended power output interface when the first set of battery cells and the second set of battery cells are connected in series through the switch. It's safe and reliable when charging the external device.

The output of multiple voltages on battery packs has become a new trend in the electrical tool industry. The present dual-voltage battery packs include two sets of batteries that can output two sets of voltages. It is necessary to add a charging port (usually a USB interface) to recharge the phones and other devices. When using the USB interface, the USB circuit cannot take power from one set of battery alone, because this will cause the battery voltage on both sides to be unbalanced and there is a risk of use.
A safe and reliable battery pack that overcomes the above-mentioned problems is desired.


The present invention provides a lumen support stent with a clear through-lumen for use in a body lumen. The stent is formed from at least one series of sliding and locking radial elements and at least one ratcheting mechanism comprising an articulating element and a plurality of stops. The ratcheting mechanism permits one-way sliding of the radial elements from a collapsed diameter to an expanded diameter, but inhibits radial recoil from the expanded diameter.

This invention relates to expandable medical implants for maintaining support of a body lumen.
An important use of stents is found in situations where part of the vessel wall or stenotic plaque blocks or occludes fluid flow in the vessel. Often, a balloon catheter is utilized in a percutaneous transluminal coronary angioplasty procedure to enlarge the occluded portion of the vessel. However, the dilation of the occlusion can cause fissuring of atherosclerotic plaque and damage to the endothelium and underlying smooth muscle cell layer, potentially leading to immediate problems from flap formation or perforations in the vessel wall, as well as long-term problems with restenosis of the dilated vessel. Implantation of stents can provide support for such problems and prevent re-closure of the vessel or provide patch repair for a perforated vessel. Further, the stent may overcome the tendency of diseased vessel walls to collapse, thereby maintaining a more normal flow of blood through that vessel.
Significant difficulties have been encountered with all prior art stents. Each has its percentage of thrombosis, restenosis and tissue in-growth, as well as various design-specific disadvantages.
Examples of prior developed stents have been described by Balcon et al., "Recommendations on Stent Manufacture, Implantation and Utilization," European Heart Journal (1997), vol. 18, pages 1536-1547, and Phillips, et al., "The Stenter's Notebook," Physician's Press (1998), Birmingham, Mich. The first stent used clinically was the self-expanding "Wallstent" which comprised a metallic mesh in the form of a Chinese fingercuff. This design concept serves as the basis for many stents used today. These stents were cut from elongated tubes of wire braid and, accordingly, had the disadvantage that metal prongs from the cutting process remained at the longitudinal ends thereof. A second disadvantage is the inherent rigidity of the cobalt based alloy with a platinum core used to form the stent, which together with the terminal prongs, makes navigation of the blood vessels to the locus of the lesion difficult as well as risky from the standpoint of injury to healthy tissue along the passage to the target vessel. Another disadvantage is that the continuous stresses from blood flow and cardiac muscle activity create significant risks of thrombosis and damage to the vessel walls adjacent to the lesion, leading to restenosis. A major disadvantage of these types of stents is that their radial expansion is associated with significant shortening in their length, resulting in unpredictable longitudinal coverage when fully deployed.
Among subsequent designs, some of the most popular have been the Palmaz-Schatz slotted tube stents. Originally, the Palmaz-Schatz stents consisted of slotted stainless steel tubes comprising separate segments connected with articulations. Later designs incorporated spiral articulation for improved flexibility. These stents are delivered to the affected area by means of a balloon catheter, and are then expanded to the proper size. The disadvantage of the Palmaz-Schatz designs and similar variations is that they exhibit moderate longitudinal shortening upon expansion, with some decrease in diameter, or recoil, after deployment. Furthermore, the expanded metal mesh is associated with relatively jagged terminal prongs, which increase the risk of thrombosis and/or restenosis. This design is considered current state of the art, even though their thickness is 0.004 to 0.006 inches.
Another type of stent involves a tube formed of a single strand of tantalum wire, wound in a sinusoidal helix; these are known as coil stents. They exhibit increased flexibility compared to the Palmaz-Schatz stents. However, they have the disadvantage of not providing sufficient scaffolding support for many applications, including calcified or bulky vascular lesions. Further, the coil stents also exhibit recoil after radial expansion.
One stent design described by Fordenbacher, employs a plurality of elongated parallel stent components, each having a longitudinal backbone with a plurality of opposing circumferential elements or fingers. The circumferential elements from one stent component weave into paired slots in the longitudinal backbone of an adjacent stent component. By incorporating locking means within the slotted articulation, the Fordenbacher stent may minimize recoil after radial expansion. In addition, sufficient numbers of circumferential elements in the Fordenbacher stent may provide adequate scaffolding. Unfortunately, the free ends of the circumferential elements, protruding through the paired slots, may pose significant risks of thrombosis and/or restenosis. Moreover, this stent design would tend to be rather inflexible as a result of the plurality of longitudinal backbones.
Some stents employ "jelly roll" designs, wherein a sheet is rolled upon itself with a high degree of overlap in the collapsed state and a decreasing overlap as the stent unrolls to an expanded state. Examples of such designs are described in U.S. Pat. Nos. 5,421,955 to Lau, U.S. Pat. Nos. 5,441,515 and 5,618,299 to Khosravi, and U.S. Pat. No. 5,443,500 to Sigwart. The disadvantage of these designs is that they tend to exhibit very poor longitudinal flexibility. In a modified design that exhibits improved longitudinal flexibility, multiple short rolls are coupled longitudinally. See e.g., U.S. Pat. No. 5,649,977 to Campbell and U.S. Pat. Nos. 5,643,314 and 5,735,872 to Carpenter. However, these coupled rolls lack vessel support between adjacent rolls.
Another form of metal stent is a heat expandable device using Nitinol or a tin-coated, heat expandable coil. This type of stent is delivered to the affected area on a catheter capable of receiving heated fluids. Once properly situated, heated saline is passed through the portion of the catheter on which the stent is located, causing the stent to expand. The disadvantages associated with this stent design are numerous. Difficulties that have been encountered with this device include difficulty in obtaining reliable expansion, and difficulties in maintaining the stent in its expanded state.
Self-expanding stents are also available. These are delivered while restrained within a sleeve (or other restraining mechanism), that when removed allows the stent to expand. Self-expanding stents are problematic in that exact sizing, within 0.1 to 0.2 mm expanded diameter, is necessary to adequately reduce restenosis. However, self-expanding stents are currently available only in 0.5 mm increments. Thus, greater selection and adaptability in expanded size is needed.
In summary, there remains a need for an improved stent: one that has smoother marginal edges, to minimize restenosis; one that is small enough and flexible enough when collapsed to permit uncomplicated delivery to the affected area; one that is sufficiently flexible upon deployment to conform to the shape of the affected body lumen; one that expands uniformly to a desired diameter, without change in length; one that maintains the expanded size, without significant recoil; one that has sufficient scaffolding to provide a clear through-lumen; one that employs a thinner-walled design, which can be made smaller and more flexible to reach smaller diameter vessels; and one that has a thinner-walled design to permit faster endothelialization or covering of the stent with vessel lining, which in turn minimizes the risk of thrombosis from exposed stent materials.

Expandable stent with sliding and locking radial elements


An electronic device is provided with an enclosure having a side wall in which vent holes are formed, a heat generator stored in the enclosure, a radiator disposed adjacent to the vent holes, a heat receiver thermally connected to the heat generator, a heat transmission member having one end thermally connected to the heat receiver and the other end thermally connected to the radiator, a fan disposed adjacent to the radiator to generate cooling air toward the radiator, and a seal member that seals a gap formed between the radiator and the side wall having the vent holes formed therein.

1. Field
The present invention relates to an electronic device, and more particularly to an electronic device which contains a heat generator such as a semiconductor, and a cooling unit for cooling the heat generator.
2. Description of the Related Art
Accompanied with the recent trend of speeding up of the information processing performed by an electronic device or a personal computer, the heat value of the semiconductor element such as CPU has been increasing. Accordingly, forced cooling of the semiconductor element has become indispensable for maintaining its performance.
Besides the CPU, the heat value of the semiconductor element for the high-speed signal processing, for example, a graphic controller used for image processing has been increasing. Recently, the number of the electronic device of type which contains a plurality of semiconductor elements requiring forced cooling in a single enclosure has been increasing.
The forced cooling of the CPU or the like has been performed in various ways. For example, the forced air cooling is performed by transmitting heat of a heat receiver thermally connected to the heat generator (CPU) to a radiator through a heat pipe so as to perform the forced cooling of the radiator using a fan and the like.
JP-A 2003-97892 discloses the electronic device as one of the aforementioned types of the technology. The disclosed electronic device is a notebook PC having its main body connected to a panel portion via hinges such that they are opened and closed. The main body contains components in a thin enclosure, for example, the heat generator such as the CPU and a cooling unit. Vent holes are formed in a side wall of the enclosure, and the cooling unit is disposed adjacent to the vent holes. Cooling air of the cooling unit is discharged outside the enclosure through those vent holes.
The cooling unit includes a radiator, a cooling fan, a heat pipe, and a heat receiver. The heat receiver at one end of the heat pipe is thermally connected to the heat generator (CPU). The other end of the heat pipe is thermally connected to the radiator such that the heat of the heat generator (CPU) is transmitted to the heat pipe via the heat receiver, and further transmitted to the radiator.
Heat exchange is performed between a plurality of fins of the radiator and cooling air generated by the cooling fan. The heated cooling air is discharged outside through the vent holes.
In the electronic device of the disclosed type, all the heated cooling air cannot be discharged outside the enclosure. The heated cooling air partially flows back into the enclosure.
The heated cooling air may be efficiently discharged by arranging the cooling fin and the radiator as adjacent to the vent holes (side wall) as possible. However, it is difficult to completely eliminate the gap between the side wall and the radiator in view of operability of assembling the cooling fin and the radiator with the enclosure or limitation in arrangement of the fixation member.
Part of the heated cooling air impinges against the wall of the vent hole, and passes through the gap to return into the enclosure as the flow back of the cooling air.
As a result, the temperature inside the enclosure increases to raise the temperature of the cooling air generated by the cooling fan. This may deteriorate the performance for cooling the heat generator. Accordingly, the cooling fan or radiator are required to be enlarged conforming to a predetermined requirement for the cooling performance.
The temperature rise in the enclosure may adversely affect other semiconductor elements and electronic parts which require no forced cooling.


A pressure sensing apparatus including: at least one deflectable diaphragm having a center, wherein each diaphragm supports: at least one positive piezoresistive gauge and at least one negative piezoresistive gauge coupled in series across a voltage differential in a half-Wheatstone bridge configuration having an output between the positive and negative piezoresistive gauges; and, a compensating piezoresistive gauge coupled in series with the half-Wheatstone bridge configuration across the voltage differential; wherein, the compensating piezoresistive gauge is nearer the center of the diaphragm than the negative piezoresitive gauge, the negative piezoresitive gauge is nearer the center of the diaphragm than the positive piezoresitive gauge, and the compensating piezoresistive gauge linearizes the half-Wheatstone bridge output.

The prior art includes various circuits which operate to linearize the output of piezoresistive transducers. Essentially, piezoresistive devices such as transducers will exhibit a varying output voltage upon application of a varying pressure or force. In regard to transducers, in general, it is desirable that the output voltage be linearly related to the applied pressure or force and thus exhibit a straight line characteristic. In practice such devices do not exhibit a straight line characteristic but are non-linear and, for example, the output voltage for a certain range of pressures does not follow the same slope as for lower ranges of pressures. This results in a non-linear transfer characteristic of the transducer.
Techniques exist in the prior art as to how to achieve compensation of such a device. The prior art has many examples of circuits which will increase the voltage applied to the transducer as the pressure increases. In this way the non-linearity is compensated for. Non-linearities can arise for many reasons in piezo-resistive pressure sensors. These include electrical, material and mechanical non-linearities, all of which add to a sensor's overall non-linearity. Material and electrical non-linearities tend to be random and are usually not large. Mechanical non-linearities are generally small as well. However, they can become large when the diaphragm deflection is not small compared to its thickness. This occurs with low pressure transducers or when a high output is needed for other pressure ranges. In these situations the diaphragm does not deflect as much as it would under linear conditions, which therefore leads to a loss in output at greater pressures. This non-linearity is known as a negative non-linearity. The negative non-linearities are a problem for all high accuracy pressure sensors but is especially troublesome when two half bridges are used to make a differential sensor.
Reference is made to U.S. Pat. No. 6,612,179, entitled Method and Apparatus for the Determination of Absolute Pressure and Differential Pressure Therefrom, issued on Sep. 2, 2003 to A. D. Kurtz, one of the inventors herein and assigned to Kulite Semiconductor Products, Inc., the assignee herein. That patent shows a combination absolute and differential pressure sensing device, which includes a plurality of absolute pressure transducers. Each transducer includes a plurality of half-bridge piezoresistive structures and means for selectively coupling at least one of the plurality of half-bridge structures of a first absolute transducer to at least one resistor or half-bridge of another piezoresistive structure. This forms a half-active, full Wheatstone bridge circuit, which can be adapted to measure an absolute pressure. Furthermore, at least one other of the plurality of half-bridge structures is coupled to another half-bridge structure to form a full Wheatstone bridge adapted to measure differential pressure. In this particular arrangement, small changes in the output at high pressures will lead to large differences in output in differential pressure at different line pressures. Namely, the output with the main transducer at 25% and the reference at 0 will be larger than the output with the main transducer at 100% and the reference at 75%. The entire disclosure of U.S. Pat. No. 6,612,179 is hereby incorporated by reference as if being set forth in its entirety herein.
As indicated above, there exist ways to compensate for such a non linearity that use active elements, such as amplifiers and transistors. For an example of such a compensation technique, reference is made to U.S. Pat. No. 4,419,620, entitled Linearizing Circuits for a Semiconductor Pressure Transducer, issued on Dec. 6, 1983 to A. D. Kurtz et al, and assigned to the assignee herein. In that patent there is shown a circuit which linearizes the output of a differential pressure transducer. The circuit includes first and second operational amplifiers, where each amplifier is associated with threshold devices such as diodes, so that one amplifier will be active for one condition of output polarity while the other amplifier will be active for the other condition of output polarity. The conditions can be positive and negative. The output of the amplifiers are connected to a common terminal, which provides a compensating biasing voltage to the transducer. The voltage varies in a "V" shaped characteristic to enable one to achieve a linear output voltage from the transducer for both positive and negative pressure differences. The entire disclosure of U.S. Pat. No. 4,419,620 is hereby incorporated by reference as if being set forth in its entirety herein.
The approach of U.S. Pat. No. 4,419,620 requires the use of active elements such as transistors and diodes. The active elements are subjected to many other problems if they are not properly isolated. These problems are associated as well with changes in temperature and voltage changes, whereby other separate compensating techniques are required for the active devices.
It would be desirable to enable compensation and linearization of a differential sensor device, such as a device including two half-bridges, and to compensate or linearize the device using only simple passive components for high temperature or low voltage applications.

Apparatus and methods for linearizing piezoresistive wheatstone bridges


An object detecting apparatus for a vehicle has a light radiation unit and a light receiver unit disposed in a case for detecting an object or a distance to the object. When a vehicle is at a stop, the apparatus detects an output power of a laser light radiated from the light radiation unit by the light receiving unit and feedback-controls the output power of the laser light to a predetermined level based on the detected output power of the laser light. The feedback control is effected by an amplifier circuit, a pulse width detector circuit and a current regulator circuit. Thus, the output power of the laser light is reduced not to damage human eyes when the vehicle is at a stop.

A conventional object detecting apparatus mounted on a vehicle uses a laser light, for instance, to detect a distance to an object such as a preceding vehicle. This detecting apparatus intermittently drives a laser diode to radiate the laser light towards the forward area of the vehicle, and detects the laser light reflected from the forward object by a photo sensor. The detecting apparatus measures the distance to the forward object based on a time difference between a light radiation time and a light reception time.
Specifically, as disclosed in JP 2002-031685A, the detecting apparatus comprises a light radiation unit for radiating a laser light, a polygon mirror and a light receiver unit for receiving a reflected laser light. The polygon mirror is shaped in a frustum of a hexagonal pyramid and rotatable as a scanning mirror.
According to this construction, the polygon mirror reflects the laser light radiated from the light radiation unit and directs it to the forward area of the vehicle. As the polygon mirror is rotated and the laser light from the light radiation unit is directed to each side surface of the polygon mirror, so that the angle of reflection of the laser light at the polygon mirror is adjusted to scan a predetermined range of the forward area of the vehicle by the laser light. The receiver unit includes a Fresnel lens and a light receiving device to receive the laser light reflected from the forward object and measure the distance to the object.
It is required to increase the output power of the laser light to cover a long distance or a wide area. The laser light of increased output power level is not desired so that human eyes may be protected from receiving the laser light.
In the case of a vehicle stop-and-go system which automatically stops and starts a vehicle in correspondence with a stop and start of a preceding vehicle, the output power of the laser light is decreased when the vehicle is at a stop. This is because it is more likely that the human eyes may receive the laser light when the vehicle is at a stop.
For this reason, the output power of the laser light must be controlled precisely. It is however difficult because the current-to-power characteristics of laser diodes vary from diode to diode.

Object detecting apparatus having light radiation power regulating function


This invention relates to a liquid crystal display device that minimizes picture quality deterioration caused by signal distortion. The present invention selects an area within an image, which has a rapidly increasing or decreasing gamma voltage, identifies a border delineating two different intensity regions within the area, computes an average intensity within the area, and weights the gamma voltage for each pixel within the area based on the average intensity. A liquid crystal display device according to the present invention includes: a liquid crystal display panel; an analyzer analyzing a brightness characteristic of data in an area within an image; an average video signal voltage generator calculating an average brightness value in the area; a bordering value processing part calculating a bordering brightness value in the area; and a weighting part adjusting a pixel voltage according to the average brightness value and the bordering brightness value.

1. Field of the Invention
The present invention relates to liquid crystal display devices for minimizing picture quality deterioration caused by signal distortion.
2. Description of the Related Art
Generally, a liquid crystal display device controls the light transmittance of a liquid crystal by use of electric fields, thereby displaying a picture.
FIG. 1 is a diagram representing a liquid crystal display device of the related art. Referring to FIG. 1, the related art liquid crystal display device includes a liquid crystal display panel 1; a plurality of data tape carrier packages (TCP) 8, which are connected between the liquid crystal display panel 1 and data printed circuit boards (PCB) 12; a plurality of gate TCPs 14A to 14D connected to another side of the liquid crystal display panel 1; data driver integrated circuits (IC) 10 mounted on each of the data TCPs 8; and gate drive ICs 16A to 16D mounted on each of the gate TCPs 14A to 14D.
The liquid crystal display panel 1 includes a lower substrate 2 where a thin film transistor array is formed together with various signal lines; an upper substrate 4 where a color filter array is formed; and a liquid crystal, which is injected between the lower substrate 2 and the upper substrate 4. The liquid crystal display panel 1 includes a picture display area 21, wherein the picture display area 21 includes liquid crystal cells that are defined by the crossing of the gate lines 20 and the data lines 18. Data pads extend from the data line 18, and gate pads extend from the gate line 20, in the outer area of the lower substrate 2 located at an outer part of the picture display area 21.
The data TCP 8 has the data drive IC 10 mounted on it and input pads 24 and output pads 25 electrically connected to the data driver IC 10. The input pads 24 of the data TCP 8 are electrically connected to the output pads 25 of a data PCB 12 through an anisotropic conductive film (hereinafter "ACF"), and the output pads 25 are electrically connected to the data pads on the lower substrate 2 through the ACF.
The data driver ICs 10 convert a digital pixel data signal into an analog pixel voltage signal and supply the analog pixel signal to the corresponding data line 18 on the liquid crystal display panel 1.
The gate TCP 14A to 14D respectively have gate driver ICs 16A to 16D mounted on them, a gate drive signal transmission line group 28, and the output pads formed to connected to the gate driver ICs 16A to 16D. The gate driver signal transmission line group 28 is electrically connected to the signal line group 26 on the lower substrate 2 through the ACF, and the output pads 30 are electrically connected to the gate pads on the lower substrate 2 through the ACF.
The gate driver ICs 16A to 16D sequentially supply a scanning signal, i.e., gate high voltage signal VGH, to the gate lines 20 in response to input control signals. The gate driver ICs 16A to 16D supply a gate low voltage signal VGL to the gate lines in the remaining period except for a period when the gate high voltage signal VGH is supplied.
The signal line group 26 generally includes the following: signal lines that supply DC voltage signals like the gate high voltage signal VGH; the gate low voltage signal VGL; a common voltage signal Vcom; a ground voltage signal GND and a power supply voltage signal VCC that are supplied from a power supply; and gate control signals like a gate start pulse GSP, a gate shift clock signal GSC and a gate output enable signal GOE, which are supplied from a timing controller.
The signal line group 26 of the related art liquid crystal display device is formed in a minute parallel pattern in a very limited narrow space, such as the pad area, which is located at the outer area of the picture display part 21. The signal line group 26 is formed of the same gate metal layer as the gate lines 20. The gate metal is generally a metal that has a relatively high specific resistance 0.046, like AlNd. In this way, the signal line group 26 is formed in a minute pattern in a limited area and of a gate metal which has the relatively high specific resistance. Accordingly, the signal line group 26 includes a relatively high line resistance component X in comparison with the signal lines formed of a copper thin film in the existing gate PCB. Further, the ACF (not shown) for connecting the signal line group 26 to the gate drive signal transmission line group 28 includes a designated connection resistance component Y. In addition, the gate driver signal transmission line group 28 formed on a chip-on-film (COF), or the gate TCP 14A to 14D, include a designated line resistance component Z. These resistance components have a difference as much as X+2Y+2Z between the adjacent ICs. The resistance components cause line resistance to increase with increasing distance from the data PCB 12, thereby attenuating the signal supplied through the signal line group 26. Especially, the common voltage Vcom signal which is the standard of the gate drive signals is distorted by such a resistance, thereby deteriorating the quality of a picture which is displayed in the picture display part 21.
The signal line group 26 has line resistances (a, b, c, d) proportional to its line length, and is connected in series through the first and fourth gate TCPs 14A to 14D. The common voltage Vcom supplied to each gate driver IC 16A to 16D is changed by the line resistances (a, b, c, d) of the signal line group 26. Accordingly, the first to fourth common voltages VCOM1 to VCOM4 have a relationship such that VCOM1>VCOM2>VCOM3>VCOM4. Accordingly, a difference in brightness occurs between horizontal line blocks A to D, which are respectively connected to the gate driver ICs 16A to 16D. The brightness difference of the horizontal line block A to D is shown in a horizontal line 32 phenomenon to make a screen appear to be divided, thereby resulting in a cross-talk phenomenon caused by the resistance between lines as well as a picture quality deterioration.
FIG. 2 illustrates a vertical stripe pattern, which is a test pattern whereby the distortion of the common voltage Vcom is most intensely generated. Herein, an equivalent circuit between a panel and a drive circuit can be expressed as illustrated in FIG. 3.
Referring to FIG. 3, the related art cross-talk phenomenon results from an alternating current Iac, which is imparted to the resistor R_ITO of the common electrode by energy that is stored in capacitors Cb and Cg, which are between a black pixel V_B and a gray pixel V_G. The alternating current Iac forms a path which is connected to a third node Vc and a gamma resistor R_gamma through a pad resistor R_pad that makes the driver IC in contact with the panel. A horizontal cross-talk is generated in a bordering part of a black bar due to a voltage coupling resulting from a difference between the voltage of the common electrode of a second node Vb and a gamma voltage of the third node Vc.

Liquid crystal display apparatus and driving method thereof