A low dielectric constant, thermally stable hydrogenated oxidized silicon carbon film which can be used as an interconnect dielectric in IC chips is disclosed. Also disclosed is a method for fabricating a thermally stable hydrogenated oxidized silicon carbon low dielectric constant film utilizing a plasma enhanced chemical vapor deposition technique. Electronic devices containing insulating layers of thermally stable hydrogenated oxidized silicon carbon low dielectric constant materials that are prepared by the method are further disclosed. To enable the fabrication of thermally stable hydrogenated oxidized silicon carbon low dielectric constant film, specific precursor materials having a ring structure are preferred.

The present invention generally relates to a new hydrogenated oxidized silicon carbon (SiCOH) low dielectric constant material which is thermally stable to at least 350xc2x0 C. and a method for fabricating films of this material and electronic devices containing such films and more particularly, relates to a low dielectric constant, thermally stable hydrogenated oxidized silicon carbon (SiCOH) film for use as an intralevel or interlevel dielectric, cap material, or hard mask/polish stop in a ULSI back-end-of-the-line (BEOL) wiring structure, electronic structures containing the films and a method for fabrication such films and structures.
The continuous shrinking in dimensions of electronic devices utilized in ULSI circuits in recent years has resulted in increasing the resistance of the BEOL metalization as well as increasing the capacitance of the intralayer and interlayer. This combined effect increases signal delays in ULSI electronic devices. In order to improve the switching performance of future ULSI circuits, low dielectric constant (k) insulators and particularly those with k significantly lower than that of silicon oxide are needed to reduce the capacitances. Dielectric materials that have low k values have been commercially available, for instance, one of such materials is polytetrafluoroethylene (PTFE) with a k value of 2.0. However, these dielectric materials are not thermally stable when exposed to temperatures above 300xcx9c350xc2x0 C. which renders them useless during integration of these dielectrics in ULSI chips which require a thermal stability of at least 400xc2x0 C.
The low-k materials that have been considered for applications in ULSI devices include polymers containing Si, C, O, such as methylsiloxane, methylsesquioxanes, and other organic and inorganic polymers. For instance, materials described in a paper xe2x80x9cProperties of new low dielectric constant spin-on silicon oxide based dielectricsxe2x80x9d by N. Hacker et al., published in Mat. Res. Soc. Symp. Proc., vol. 476 (1997) p25 appear to satisfy the thermal stability requirement, even though some of these materials propagate cracks easily when reaching thicknesses needed for integration in the interconnect structure when films are prepared by a spin-on technique. Furthermore, the precursor materials are high cost and prohibitive for use in mass production. In contrast to this, most of the fabrication steps of VLSI and ULSI chips are carried out by plasma enhanced chemical or physical vapor deposition techniques. The ability to fabricate a low-k material by a PECVD technique using readily available processing equipment will thus simplify its integration in the manufacturing process and create less hazardous waste.
It is therefore an object of the present invention to provide a low dielectric constant material of hydrogenated oxidized silicon carbon which is thermally stable to at least 350xc2x0 C. and exhibits very low crack propagation.
It is another object of the present invention to provide a method for fabricating a low dielectric constant and thermally stable hydrogenated oxidized silicon carbon film.
It is a further object of the present invention to provide a method for fabricating a low dielectric constant, thermally stable hydrogenated oxidized silicon carbon film from a precursor which contains Si, C, O and H and which may have a ring structure.
It is another further object of the present invention to provide a method for fabricating a low dielectric constant, thermally stable hydrogenated oxidized silicon carbon film from a precursor mixture which contains atoms of Si, C, O, and H.
It is still another further object of the present invention to provide a method for fabricating a low dielectric constant, thermally stable hydrogenated oxidized silicon carbon film in a parallel plate plasma enhanced chemical vapor deposition chamber.
It is yet another object of the present invention to provide a method for fabricating a low dielectric constant, thermally stable hydrogenated oxidized silicon carbon film for use in electronic structures as an intralevel or interlevel dielectric in a BEOL interconnect structure.
It is still another further object of the present invention to provide a method for fabricating a thermally stable hydrogenated oxidized silicon carbon film of low dielectric constant capable of surviving a process temperature of at least 350xc2x0 C. for four hours.
It is yet another further object of the present invention to provide a low dielectric constant, thermally stable hydrogenated oxidized silicon carbon film that has low internal stresses and a dielectric constant of not higher than 3.6.
It is still another further object of the present invention to provide an electronic structure incorporating layers of insulating materials as intralevel or interlevel dielectrics in a BEOL wiring structure in which at least one of the layers of insulating materials comprise hydrogenated oxidized silicon carbon films.
It is yet another further object of the present invention to provide an electronic structure which has layers of hydrogenated oxidized silicon carbon films as intralevel or interlevel dielectrics in a BEOL wiring structure which contains at least one dielectric cap layer formed of different materials for use as a reactive ion etching mask, a polish stop or a diffusion barrier.
It is still another further object of the present invention to provide an electronic structure with intralevel or interlevel dielectrics in a BEOL wiring structure which has at least one layer of hydrogenated oxidized silicon carbon films as reactive ion etching mask, a polish stop or a diffusion barrier.
In accordance with the present invention, a novel hydrogenated oxidized silicon carbon (SiCOH) low dielectric constant material that is thermally stable to at least 350xc2x0 C. is provided. The present invention further provides a method for fabricating a thermally stable, low dielectric constant hydrogenated oxidized silicon carbon film by reacting a precursor gas containing atoms of Si, C, O, and H in a parallel plate plasma enhanced chemical vapor deposition chamber. The present invention still further provides an electronic structure that has layers of insulating materials as intralevel or interlevel dielectrics used in a BEOL wiring structure wherein the insulating material can be a hydrogenated oxidized silicon carbon film.
In a preferred embodiment, a method for fabricating a thermally stable hydrogenated oxidized silicon carbon film can be carried out by the operating steps of first providing a parallel plate plasma enhanced chemical vapor deposition chamber, positioning an electronic structure in the chamber, flowing a precursor gas containing atoms of Si, C, O, and H into the chamber, depositing a hydrogenated oxidized silicon carbon film on the substrate, and optionally heat treating the film at a temperature not less than 300xc2x0 C. for a time period of at least 0.5 hour. The method may further include the step of providing a parallel plate reactor which has a conductive area of a substrate chuck between about 300 cm2 and about 700 cm2, and a gap between the substrate and a top electrode between about 1 cm and about 10 cm. A RF power is applied to one of the electrodes at a frequency between about 12 MHZ and about 15 MHZ. The substrate may be positioned on the powered electrode or on the grounded electrode. An optional heat treating step may further be conducted at a temperature not higher than 300xc2x0 C. for a first time period and then at a temperature not lower than 380xc2x0 C. for a second time period, the second time period is longer than the first time period. The second time period may be at least 10 folds of the first time period.
The precursor utilized can be selected from molecules with ring structures such as 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS, or C4H16O4Si4), tetraethylcyclotetrasiloxane (C8H24O4Si4), or decamethylcyclopentasiloxane (C10H30O5Si5). However, other precursors comprising Si, C, O, and H containing gases may also be used. Such precursors may be selected from the group of methylsilanes, such as tetramethylsilane (Si(CH3)4) or trimethylsilane (SiH(CH3)3)), with or without the addition of oxygen to the feed gas. The precursor can be delivered directly as a gas to the reactor delivered as a liquid vaporized directly within the reactor, or transported by an inert carrier gas such as helium or argon. The precursor mixture may further contain elements such as nitrogen, fluorine or germanium.
The deposition step for the hydrogenated oxidized silicon carbon low dielectric constant film may further include the steps of setting the substrate temperature at between about 25xc2x0 C. and about 400xc2x0 C., setting the RF power density at between about 0.02 W/cm2 and about 1.0 W/cm2, setting the precursor flow rate at between about 5 sccm and about 200 sccm, setting the chamber pressure at between about 50 mTorr and about 3 Torr, and setting a substrate DC bias at between about 0 VDC and about xe2x88x92400 VDC. The deposition process can be conducted in a parallel plate type plasma enhanced chemical vapor deposition chamber.
The present invention is further directed to an electronic structure which has layers of insulating materials as intralevel or interlevel dielectrics in a BEOL interconnect structure which includes a pre-processed semiconducting substrate that has a first region of metal embedded in a first layer of insulating material, a first region of conductor embedded in a second layer of insulating material which comprises SiCOH, said second layer of insulating material being in intimate contact with said first layer of insulating material, said first region of conductor being in electrical communication with said first region of metal, and a second region of conductor being in electrical communication with said first region of conductor and being embedded in a third layer of insulating material comprises SiCOH, said third layer of insulating material being in intimate contact with said second layer of insulating material. The electronic structure may further include a dielectric cap layer situated in-between the first layer of insulating material and the second layer of insulating material, and may further include a dielectric cap layer situated in-between the second layer of insulating material and the third layer of insulating material. The electronic structure may further include a first dielectric cap layer between the second layer of insulating material and the third layer of insulating material, and a second dielectric cap layer on top of the third layer of insulating material.
The dielectric cap material can be selected from silicon oxide, silicon nitride, silicon oxinitride, refractory metal silicon nitride with the refractory metal being Ta, Zr, Hf or W, silicon carbide, silicon carbo-oxide, and their hydrogenated compounds. The first and the second dielectric cap layer may be selected from the same group of dielectric materials. The first layer of insulating material may be silicon oxide or silicon nitride or doped varieties of these materials, such as PSG or BPSG. The electronic structure may further include a diffusion barrier layer of a dielectric material deposited on at least one of the second and third layer of insulating material. The electronic structure may further include a dielectric layer on top of the second layer of insulating material for use as a RIE hard mask/polish stop layer and a dielectric diffusion barrier layer on top of the dielectric RIE hard mask/polish-stop layer. The electronic structure may further include a first dielectric RIE hard mask/polish-stop layer on top of the second layer of insulating material, a first dielectric RIE diffusion barrier layer on top of the first dielectric polish-stop layer, a second dielectric RIE hard mask/polish-stop layer on top of the third layer of insulating material, and a second dielectric diffusion barrier layer on top of the second dielectric polish-stop layer. The electronic structure may further include a dielectric cap layer of same materials as mentioned above between an interlevel dielectric of SiCOH and an intralevel dielectric of SiCOH.

Hydrogenated oxidized silicon carbon material

International Business Machines Corporation


A system, computer-readable storage medium storing at least one program, and a computer-implemented method for providing custom features in a game is provided. A themed game board associated with a first set of rules of a computer-implemented game is generated. The first set of rules relates to a theme of the themed game board and is different than a second set of rules associated with a game board without a theme. Game board display data is provided to a first client device of a first player to display the themed game board. A move on the themed game board is received from the first client device, and a score associated with the move is generated. The score is based on the first set of rules relating to the theme, where the score is different than a score associated with the move on the game board without a theme.

The popularity of computer-implemented games is ever-growing, and this popularity has been recognized by many entities acquiring value through the popularity of these games. For example, advertising through the user interfaces for these games has become an effective way to market products and services to consumers playing these games.
While these games may be useful platforms for communicating to players, the effect of such communication is typically limited to the display of an advertisement, and little interaction with the players is involved.


A Numerical Inventory Control Device for holding and then dispensing one or more items contained within the device wherein the items are gradually moved from the back toward the front of the device by a moving slideable pusher which is biased against a constant force coil spring contained in a dispenser housing attached at the back end of the pusher and wherein one end of the coil spring is affixed to the dispenser housing wherein, when product, near the front of the housing, is removed the constant force spring will cause the pusher to advance the next product toward the front for dispensing purposes. An inventory indicator sheet, essentially in the form of an endless belt, is attached at one end to the front side of the pusher and at the other end to the rear of the pusher and has one or more rows of numbers thereon, which indicate, at the front of the device, the quantity of units remaining in the dispensing device.

1. Field of the Invention
The present invention generally involves the field of technology pertaining to a device principally for use in retail stores wherein merchandise, such as cigarette packages, are stored in rows, on shelves, and wherein the rows, which can be one or more, are perpendicular to the storage shelves, and are parallel to each other. Usually, viewed from the vantage point of a purchaser, only the first item in a row, at the front of the storage unit, is viewed and, obviously, the merchandise can be removed from the front, the middle, or the rear of the shelve and thus there is no way of knowing how many items, in this case, packages of cigarettes, are still available for sale.
Still further, obviously, if packages are removed, randomly, from the front, back, or middle and also from row to row from the display it greatly disturbs the visual appearance of the shelves. Applicant's prior U.S. Pat. No. 4,742,936 which issued May 10, 1988 substantially resolved the foregoing problems but it is submitted that the instant invention further substantially improves on that device in that a negator spring is provided rather than a coiled spring and three tracks of numbers are provided, rather than one, on an indicator sheet for reasons to be explained below. Further, the indicator sheet itself is no longer a self-coiling sheet but rather is in the form of an endless belt both ends of which are attached to a moveable platform or pusher which urges the merchandise forward. The multiple rows or tracks of numbers on the indicator sheet allows for different thickness of product in the same row since the numbers are staggered in accordance with product thickness.
2. Description of the Prior Art
The closest prior art references known to applicant is his prior issued U.S. Pat. No. 4,742,936, which differs from this invention in the particulars indicated above. That prior patent references the R. E. Taber U.S. Pat. No. 3,416,115 regarding a self-coiling sheet which can be extended and recoiled almost indefinitely without fatigue. The Taber self-coiling sheet, as used in applicant's prior patent, required a spindle at the front of the device, a guide and a pressure plate for maintaining the sheet in a vertical position with respect to a viewing window at the front of the device. Those items are eliminated by the current invention and further incorporates three tracks of numbers, rather than one to accommodate product or merchandise of varying thickness. Applicant's prior patent comprised a dispenser for the storage and dispensing of items of identical size.
None of the references cited above, singularly, or in combination teaches or even suggests the use of the unique combination of an endless belt negator spring for urging a pusher nor an indicator sheet having multiple rows of numbers to be viewed through a viewing window at the front of the device.


Methods for removing redundancies in a video stream based on efficient pre-transmission detection of static portions of the video stream. In one embodiment supporting wireless transmission of a video stream having a series of video frames, a mathematical operation (such as a hash function, summing operation or CRC) is performed on (1) a (reconstructed) data block(s) of a video frame in order to generate a first check value and (2) a co-located data block(s) of a second, sequential video frame in order to generate a second check value. The first and second check values are compared to detect static video content in the video stream. When static video content in a video stream is detected, the static nature of the content is indicated in the compressed bit stream and the amount of wirelessly transmitted data corresponding to the static portions of the video stream may be reduced.

1. Technical Field of the Invention
The invention relates generally to wireless communication systems and the transmission of video data; and, more particularly, it relates to power and other cost saving techniques based on detection of static portions of a video stream.
2. Description of Related Art
Many approaches have been developed for improving power consumption and error robustness/concealment when transmitting video data. For example, power efficiency in a wireless video network delivering video packets may be improved by adaptively modifying the transmission power level of a wireless access point based upon device proximity data, wireless channel conditions, reception characteristics and the like. With respect to error concealment, network layer solutions may be utilized that attempt to recover the error/packet loss at the packet layer in order to provide an error free A/V stream to a receiver and its video decoder. Such solutions usually require redundant codes and retransmissions that may lead to increased power consumption in certain operating environments. Video layer solutions may also be employed, including post-processing that accepts a corrupted video stream and tries to mitigate gaps and mismatches in the decoded video frames.
As may be understood, network layer solutions and video layer solutions each involve tradeoffs. In particular, a heavily protected network layer might be very robust and resilient to errors, but usually this is accompanied by a reduction in the constant throughput of the channel and/or an increase in the effective latency of the channel. For the video layer, one of the primary considerations is the overall user experience (e.g., the perceptual experience of a user). Video should appear smooth and natural, even under variable network conditions. Under variable channel conditions, providing an acceptable user experience can be particularly challenging for real-time or near real-time video streams, as both packet loss and channel delay can have deleterious effects on perceived video quality (e.g., blocking or blurring effects, video freezing or jerkiness, and audio/video synchronization issues) and, potentially, power consumption in transmitting and receiving devices.
In order to improve utilization of available communication bandwidth for applications such as high definition streamed video, several short-range wireless personal/local area networking standards have emerged in recent years. Many of these technologies exploit high frequency and extremely high frequency radio bands (e.g., 60 GHz). Examples include the Wireless Gigabit Alliance (WGA) WiGig MAC and PHY specification/IEEE 802.11ad, WirelessHD/IEEE 802.15.3c, ECMA 387, Wireless Home Digital Interface (WHDI), and Wireless USB among others.
In addition to MAC/PHY specifications, groups such as WGA have also defined Protocol Adaptation Layers (PALs) that support specific data and display standards over the 60 GHz frequency band, including extensions for computer peripherals and display interfaces for HDTVs, monitors and projectors. For example, the WiGig Display Extension (WDE) specification supports HDMI mapping and wireless connections to DisplayPort monitors and HDMI televisions to enable cable replacement applications such as the wireless transmission of compressed or uncompressed video. The WiGig Bus Extension (WBE) specification enables a wireless version of the PCI Express (PCIe) slot, which provides connections for a wide variety of devices such as video cards and hard drives. Likewise, the Wireless Serial Extension (WSE) specification enables a high-speed serial communications link, providing a wireless version of the USB 3.0 technology. Similar approaches to wireless networking and cable replacement are being developed by other entities and industry groups.

Power saving techniques for wireless delivery of video


An analog resistive-film touch panel comprises: a plurality of transparent conductive film regions arranged along a given direction on a first member, wherein the transparent conductive film regions are formed on a surface facing a second member, and adjacent transparent conductive film regions are electrically insulated from each other; driving electrode pairs respectively provided in the transparent conductive film regions; a detection electrode pair formed on the second member whose surface facing the first member is coated with a transparent conductive film, wherein electrodes forming the detection electrode pair are arranged so as to face each other in a direction orthogonal to the direction in which electrodes forming each of the driving electrode pairs face each other; and discriminating means for discriminating, based on a voltage value detected via the detection electrode pair, which of the plurality of transparent conductive film regions has been caused to touch the transparent conductive film on the second member.

1. Field of the Invention
The present invention relates to an analog resistive-film touch panel.
2. Description of the Related Art
A touch panel is an input device typically used to provide input directly on a display screen, and is implemented by combining a coordinate detection function with a display function. Unlike other pointing devices such as a mouse, etc., that provide relative coordinate input, a touch panel, which enables an operator to easily input absolute coordinates, and can provide an interface that better matches the characteristics of human perception. Touch panels are classified as a capacitive-type, electromagnetic inductive-type, ultrasonic-type, etc., according to how the pressing on the panel is sensed. A typical one is the analog resistive-film type described, for example, in Japanese Unexamined Patent Publication No. 2006-39667. An analog resistive-film touch panel comprises planar sheet-like first and second members whose facing surfaces are each coated with a transparent conductive film, and when one surface where a potential gradient is formed across the transparent conductive film is caused to touch the transparent conductive film on the other surface by a touch operation on the panel, the absolute coordinates of the touched point on the panel are determined based on the voltage value detected at that other surface.
FIG. 20 is a perspective view illustrating a conventional analog resistive-film touch panel, and FIG. 21 is a cross-sectional view of the conventional analog resistive-film touch panel. It is to be understood that, throughout the different drawings given herein, the same reference numerals designate component elements having the same functions.
Generally, an analog resistive-film touch panel 100 comprises a film 111 and a glass 112, whose facing surfaces are each coated with a transparent conductive film 114 formed from ITO (indium tin oxide), which is a transparent conductive substance. The surface of the film 111 opposite from the surface thereof facing the glass 112 provides the touch operation surface of the touch panel 100. The film 111 and the glass 112 are bonded together, for example, by a double sided adhesive tape. The touch panel 100 is electrically connected to a host (not shown) by a cable 113.
FIGS. 22(a) and 22(b) are diagrams explaining the coordinate detection principle commonly employed in the analog resistive-film touch panel. As shown in FIG. 22(a), an electrode pair consisting of electrodes 121-1 and 121-2 is formed on the ITO-coated surface of the film 111 of the touch panel 100, and an electrode pair consisting of electrodes 122-1 and 122-2 is formed on the ITO-coated surface of the glass 112. The electrodes 121-1 and 121-2 are arranged so as to face each other in a direction orthogonal to the direction in which the electrodes 122-1 and 122-2 face each other.
When the film 111 of the touch panel 100 is touched by a finger, the film 111 deflects in substantially the vertical direction, causing the transparent conductive film formed on the film 111 to touch the transparent conductive film formed on the glass 112 (see point A in the figure). In the illustrated example, when a drive voltage of, for example, 5 volts is applied between the electrodes 121-1 and 121-2, a voltage value Va is detected, as shown in FIG. 22(b), via the electrodes 122-1 and 122-2 formed on the surface of the glass 112. The absolute coordinate of the touched point on the touch operation surface along the direction in which the electrodes 121-1 and 121-2 face each other can be calculated from the ratio of the detected voltage value Va to the voltage value of the voltage (i.e., 5 volts) applied between the electrodes 121-1 and 121-2. Since the method of calculation using such a ratio is based on the premise that the potential gradient of the same potential formed by the drive voltage applied between the electrodes 121-1 and 121-2 changes linearly, the input area where the touch panel 100 can be touched for operation is more or less limited.
FIGS. 23(a) and 23(b) are diagrams explaining the problem that may arise when the analog resistive-film touch panel illustrated in FIGS. 22(a) and 22(b) is touched by a plurality of fingers for operation. As shown in FIG. 23(a), when the film 111 of the touch panel 100 is touched by a plurality of fingers for operation (two fingers in the illustrated example), the film 111 deflects in substantially the vertical direction, causing the transparent conductive film formed on the film 111 to touch the transparent conductive film on the glass 112 at two points (points A and B in the figure). As a result, a voltage value Vc intermediate between the voltages at points A and B is detected, as shown in FIG. 23(b), via the electrodes 122-1 and 122-2 formed on the surface of the glass 112. This means that, when the analog resistive-film touch panel is touched by a plurality of fingers for operation (the so-called multi-touch operation), the plurality of pressed points on the touch panel surface cannot be recognized.
A capacitive type touch panel that can handle such a multi-touch operation is already developed. However, unlike the analog resistive-film type, the capacitive type, because of its operating principles, cannot accept pen input. Furthermore, the capacitive type is not suitable for use in an environment susceptible to static electricity or moisture.
In view of the above problem, it is an object of the present invention to provide an analog resistive-film touch panel that can recognize and discriminate a plurality of pressed positions in a multi-touch operation.


A new class of shift registers that shift the contents of a 2.sup.n bit length register up to 2.sup.n -1 positions in n cycles. Shift registers according to the present invention can be constructed to shift left, shift right, or to shift either left or right. A general implementation of this class of shift registers comprises the following hardware: 2.sup.n D flip-flops or D latches for the data register positions of the shift register; logic for each of the 2.sup.n positions to determine the input value to which the position should take on at each of the n cycles; an n bit shift count register to store a value indicating the number of positions to shift; control lines specifying whether to shift left or right; n control lines which are sequentially raised for one cycle to select a bit in the shift count register for the current cycle beginning with the most significant bit and continuing sequentially to the least significant bit; and a clock to set the selected input data to each position in the shift register.

Shift registers are widely used in digital electronics. Shift registers shift the values in a series of registers a defined number of positions either to the left or to the right as determined by a control signal. A common application of shift registers is to convert data between serial and parallel formats. Data can be loaded into a shift register in parallel and then shifted out of the register one bit at time serially, and data can also be loaded into a shift register serially and output from the shift register can be provided in parallel format.
Serial shift registers are comprised of a series of interconnected flip-flops or latches that form registers. At each clock cycle the value in each register is shifted to the adjacent register. A control signal determines whether the register values are shifted to the left or to the right. A major drawback of serial shift registers is that serial shift registers only shift one register location per clock cycle. Therefore, to shift seven positions requires seven clock cycles.
Parallel shift registers perform the complete shift operation in a single clock cycle. Thus in contrast to a serial shift register where a seven position shift requires seven clock cycles, a parallel shift register performs the seven position shift operation in a single clock cycle. The trade-off for this improved performance is that parallel shift registers require substantially more hardware than serial shift registers. A typical implementation for a parallel shift register uses four layers of AND gates to implement the control logic which moves the register values to the appropriate positions based on the number of positions of the shift operation and the direction of the shift. In addition to the control logic hardware, there is also hardware required for loading new values into the shift register and providing clock control for the different hardware stages.
A new class of shift registers that provides higher performance than serial shift registers and requires less hardware than parallel shift registers would be highly desirable.

Method and apparatus for a logarithmic shift register


The present invention provides a method of authenticating a pair of correspondents in a communication system, such as in a mobile phone network by utilizing a blend of public-key cryptography and symmetric cryptography. Each session between the mobile phone and the network consists of public-key based mutual authentication and key exchange followed by symmetric-key secure data exchange.

In constrained environments where computation power, storage space, and bandwidth are severely limited, as is the case for mobile phones, public-key cryptography was considered inefficient and therefore not a viable option. However, with the advent of faster processors and more efficient public-key cryptographic techniques, such as use of elliptic curve mathematics, traditional obstacles that prohibited use of public-key cryptography have essentially been overcome. Indeed, public-key cryptography has already been incorporated into mobile phones for applications as well as over the air service provisioning. These events allow the wireless industry to exploit the advantages of public-key cryptography in third generation systems.
Mobile phones that communicate over RF networks represent a classic example of the problems facing data security. RF networks are easy to eavesdrop so data sent by a phone can easily be monitored by an adversary and the medium itself prevents data being placed in physical opaque envelopes to ensure secrecy. In fact data sent over RF networks by mobile phones may be subject not just to eavesdropping. It is also possible for an adversary to intercept messages and replace them, delete them, or subvert them. Mobile phones users therefore need diverse security services such as the assurance that data it receives is genuine as well as the assurance that data it sends will remain secret. Data security services needed between a mobile phone and a service provider communicating over an RF network include:    Data Confidentiality: Both the mobile phone user and the service provider may want messages they exchange to remain secret. For example, the mobile phone user may want adversaries to be unable to eavesdrop on sensitive calls.    Data Integrity: Both the mobile phone user and the service provider may want messages they exchange to remain unaltered. For example, the service provider may want the assurance that the call request it receives specifies the same number that the user dialed so that the call can be completed as dialed.    Data authentication: Both the mobile phone user and the service provider may want to know the origin of data they receive. For example, the service provider may want to know the origin of a call request so that it can decide whether to complete the call.    Non-repudiation: The mobile phone user may wish to send data that is non-repudiable, meaning that the user cannot later deny sending the data. For example, the user may wish to complete a financial transaction such a buying stock over the phone.    Device or entity authentication: Both the mobile phone user and the service provider may want to know who they are communicating with. For example, the service provider may want to check that it is communicating with a paid-up mobile phone user before allowing the user to place calls. Device authentication should prohibit in particular an adversary from replaying the authorization sent by a valid user in order to gain access to the network.
Cryptography is capable of providing all these services. Encryption schemes can be used to provide data confidentiality, message authentication codes (MACs) or signature schemes can be used to provide data integrity and data authentication, and signature schemes can be used to provide non-repudiation. Entity authentication can be provided using more complicated protocols built out of encryption schemes, message authentication codes, and signature schemes.
Currently, security in cellular networks is limited primarily to device authentication. Before allowing a mobile phone network access, the network or service provider authenticates the phone using a protocol based on a message authentication code. The need for additional security services like those listed above has motivated the cellular industry to provide more comprehensive security in future third generation systems.
Authentication in current RF systems consists of device authentication based on symmetric cryptography. The mobile station is provisioned with an Authentication Key, referred to as the A-key, prior to any communication with the cellular network. The A-key is also provisioned in the Authentication Center (AC) of the service provider or home network. The process of provisioning the A-key in the mobile station is part of "service provisioning", during which other mobile station specific information is also provisioned. While there are several ways to provision the A-key, Over-The-Air Service Provisioning (OTASP) is recommended. OTASP uses the Diffie-Hellman protocol to create the A-key concurrently in the AC and the mobile station.
The A-key is then used to create session keys known as SSDs (Shared Secret Data), which are stored in the mobile station and the home network and are used to authenticate the mobile station. The SSDs are derived by hashing the A-key and other information, such as the mobile station's identity. When a user is roaming in another part of the network, the home network, at the discretion of the service provider, may decide to share the SSD with the serving network to enable the serving network to authenticate the mobile device itself using SSD. Alternatively, the service provider may require the serving network to authenticate the mobile station by checking with the home network each time. Sharing SSDs with the serving network saves signaling traffic between the two networks when the user is roaming but it also requires a degree of trust in the serving network, since knowledge of SSD enables the serving network to impersonate the mobile station.
When a mobile station powers-on, it "registers" with the network. During registration, the mobile station sends its identity to the serving network (assume that the mobile station is roaming) along with an authentication string or MAC (for simplicity, the term MAC is used throughout the rest of the document for authentication string) that is created by hashing SSD, identity information, a random challenge (32-bit number broadcast by the base station), and other information. The serving network queries the user's home network to register the mobile station. The home network, at this point, determines if the SSD is to be shared with the serving network. If so, the SSD is passed to the serving network. The serving network computes the MAC by using the same inputs as the mobile station. If the computed MAC matches the one sent by the mobile station, the mobile station is considered authenticated.
The serving network keeps the SSD associated with the mobile station for the duration of the time that the user is registered in that network. During that time, if the user originates a call (referred to as call origination), the mobile station is again authenticated in the same way as it was for registration, except that dialed digits may be used as additional input to the hash. Once again, the serving network computes the MAC and verifies if the two MACs match, thereby authenticating the mobile station. In addition, if a call is received for the user (referred to as call termination), the same procedure is repeated. In short, authentication is based on calculation of a MAC, which is a hash of SSD, a random challenge from the serving network or base station, and other input, such as mobile station's identity and/or dialed digits.
The Authentication Center in the home network may decide to update the SSD in the mobile station, referred to as SSD update. This is accomplished by sending a request to the mobile station to generate a new SSD. In this scenario, mutual authentication of the mobile station to the home network and of the home network to the mobile station is performed prior to storage of the newly generated SSD in the mobile station. The authentication of the home network consists of the following: the mobile station sends a random challenge to the AC; the AC computes a MAC using a component of SSD, the random challenge, and other information, and sends it to the mobile station; the mobile station verifies the received MAC with its own computed value.
There are a number of weaknesses with the current authentication system.
It requires the backbone network connecting the home network and the serving network to be very secure. Messages exchanged on this network must be exchanged confidentially; otherwise, an eavesdropper monitoring this channel can impersonate any active mobile stations.
It imposes high security requirements on the Authentication Center of each service provider. Maintaining the confidentiality of the A-key database at the Authentication Center is essential; otherwise, anyone who learns the contents of the database can impersonate any mobile station at any time. This problem is escalated by the fact that there is no effective disaster recovery mechanism in the event of Authentication Center compromise.
There are security concerns over SSD sharing. If the home network decides to share SSDs with serving networks, this enables the serving network to impersonate mobile stations.
The CAVE algorithm, which is used to provide authentication, itself has security concerns. CAVE has not been published and has not received widespread scrutiny by the cryptographic community. Compromise of CAVE could cause embarrassment for the cellular community, which has already been hurt by the use of unpublished algorithms, such as CMEA.
There are efficiency concerns. A large amount of communication is required on the backbone network linking the home network and the serving network. This communication is substantially increased if the home network is not sharing SSDs with the serving network since now the serving network must communicate with the home network each time it wants to authenticate the mobile station.
Most importantly, the current system does not provide sufficient security services. Device authentication provides limited security to the network since there remains the possibility that an adversary can hijack service after device authentication has been performed. Furthermore, the limited deployment of data privacy services presents a major problem since it means users are wary of placing sensitive calls over the cellular network. This issue will become particularly important in the future if the cellular industry wants to support advanced features like internet browsing and over the air financial transactions.
Global roaming, one of the most promising features of third generation systems, will heighten many of these concerns.
The deployment of a third generation system affords the cellular industry an opportunity to address the deficiencies of the current authentication system. The third generation authentication system therefore needs to meet the following requirements:
Minimization of computation time required by mobile stations for generation of appropriate keys on each access. Since authentication is used for every call, performance is an important consideration. Security should not affect the service being offered to the end-user negatively.
Ability to provide non-repudiation. This is extremely useful in services that are expected to drive deployment of third generation systems.
Minimization of extra network infrastructure. Since third generation is a migration from second generation systems, it is important to take advantage of the current infrastructure in place, where possible.
Scalability. As more and more cellular systems are brought into service each year and with many carriers aiming to provide worldwide roaming, third generation ESA and ESP should provide for the ability to scale without imposing additional costs on carriers.

Enhanced subscriber authentication protocol


Video transaction machines (VTMs) facilitate communications and transactions between customers of a financial institution and video transaction resources, such as video agents, by establishing a video session between a VTM and a video agent workstation. After a computing device of the financial institution receives information identifying the customer, VTM, or VTM location requesting the services of a video agent, the computing device may place the customer in one or more virtual queues based on an overall visit time at the VTM location. In order to maintain a visit time at the VTM location below a predetermined visit time threshold, the controller may prioritize transactions at VTMs with longer visit times over transactions at VTMs with shorter visit times.

Customers of a financial institution often complete financial transactions through bank tellers or automated devices, such as automated teller machines (ATMs). Financial transactions may include, for example, funds deposits and withdrawals, funds transfers, general account inquiries, and/or account servicing. In order to conduct financial transactions through bank tellers, customers typically must visit bank locations, which may be inconvenient for some customers. Furthermore, customers might have to wait in line for an available bank teller. While traditional ATMs might be more convenient than bank tellers for some financial transactions, customers might not be able to conduct all of their sales, servicing, and/or transactions through traditional ATMs.


An autopilot system for a vessel such as a boat receives a pre-set heading direction set by e.g. the user and also receives the apparent orientation (heading) from a heading sensor. The difference between the pre-set heading direction and the actual heading is then determined and a correction signal is generated in dependence on that difference, which correction signal is then used to control the orientation of the vessel by e.g. generating a rudder correction signal which varies the position of the rudder. In the present invention, the correction signal is further dependent on the difference between the actual heading and a reference direction such as magnetic North or South. In this way errors due to differences between the apparent orientation as detected by the heading sensor and the actual orientation of the vessel may be corrected. The correction value may alternatively, or in addition, be dependent on magnetic dip angle, and/or the vertical and/or horizontal component of the Earth's magnetic field, and/or latitude.

1. Field of the Invention
The present invention relates to an autopilot system.
2. Summary of the Prior Art
It is now common for even relatively small boats or other vessels to have an autopilot which permits automated steering of the vessel. The autopilot maintains the boat or other vessel on a pre-set heading (orientation), which pre-set heading is compared with the heading (orientation) of the boat as determined by a heading sensor (which outputs a signal called the Compass Heading). That heading sensor may be, for example, a flux gate system such as disclosed in our European patent number 0113221.


A vehicle (150) includes a fuel cell stack (151) started below freezing, by connection (158) to the vehicle propulsion system (159) within a few seconds of starting the flow of fuel (179) and oxidant (173), or when open circuit voltage (155, 156) is detected. The fuel in excess of stochiometry requirement and the oxidant in excess of at least twice stochiometric requirement, are at atmospheric pressure and at 4 kPa (0.6 psi) or more above the pressure of any water in said water passages due to a water passage vacuum pump 205, and may be below freezing. Water transport plates (84, 86, 88, 89) have water passages connected to a water circulation loop (170) including a reservoir (164) having an auxiliary heater (161) connected (160) to the stack. Warming of cell stack materials and ice in the water transport plates, heat of fusion of melting ice, warming of melted water, and evaporative cooling of water melted in the water transport plates keep the stack cool until liquid coolant is circulated.

It is generally agreed that one difficulty with utilizing fuel cells to power the propulsion system of electric vehicles is the requirement that such vehicles be operable at temperatures below that at which water will freeze. Freezing provides potential mechanical damage as a consequence of the expansion of ice, and presents problems due to the inseparability of water and the fuel cell processes. Heretofore, various methods of initiating operation of a fuel cell, preparatory to the operation of an electric vehicle, have concentrated on providing heat, either by reaction or combustion of fuel, or by means of battery power, to various water and other coolant conduits and reservoirs. Other efforts are directed toward processes designed to accelerate the rate at which a fuel cell stack will heat up to above-freezing temperatures, as a consequence of its own operation.
In copending U.S. patent application Ser. No. 10/390,439 filed Mar. 17, 2003, a PEM fuel cell stack at subfreezing temperature is connected to a vehicle propulsion system or other electric load within a few seconds or as soon as the stack provides open circuit voltage. According to the invention, the fuel cell stack is started with more than a stochiometric flow of fuel and at least stochiometric flow of oxidant, which may be at subfreezing temperatures, or not, whereby to prolong operation without localized heating, thereby permitting the vehicle (or other load) to be used during the time that the apparatus and fluids are being heated to suitable, operational temperatures.
In one known type of PEM fuel cells, the coolant water is managed through porous water transport plates, and by recirculating the water through a restriction, the water is caused to be at between 7 and 21 kPa (1 to 3 psi) below the pressure of the reactants, which are typically at atmospheric pressure. This ensures that water will not pool in the reactant gas channels, that the water is forced into the water channels, and that the hydrophilic substrates will not be flooded and will have sufficient open porosity to permit reactant diffusion. However, when freezing temperatures are encountered, the water in the reactant channels, coolant channels, water pump and other conduits of the water circulatory system is drained upon shutdown of the fuel cell system; upon startup, there is no circulating water so there is no way to maintain negative pressure in the water channels. Therefore, water can build up in the reactant channels.
In one embodiment of said copending application, at least one of the reactant gases is provided to the fuel cell stack at a pressure of at least about 4 kPa (0.6 psi) above the pressure of any water in the water channels, which typically will be about atmospheric pressure. This prevents liquid water from pooling in the reactant channels, and flooding the electrode substrates, which is particularly important in the oxidant gas reactant channel where product water can accumulate.

Vacuum assisted startup of a fuel cell at sub-freezing temperature


The present invention is directed to a spin transfer torque magnetic random access memory (STT-MRAM) device having a plurality of memory elements. Each of the plurality of memory elements comprises a magnetic reference layer with a first invariable magnetization direction substantially perpendicular to layer plane thereof; a magnetic free layer separated from the magnetic reference layer by an insulating tunnel junction layer with the magnetic free layer having a variable magnetization direction substantially perpendicular to layer plane thereof; a dielectric layer formed in contact with the magnetic free layer opposite the insulating tunnel junction layer; and a first conductive layer formed in contact with the dielectric layer opposite the magnetic free layer.

The present invention relates to a spin transfer torque magnetic random access memory (STT-MRAM) device, and more particularly, to a memory element of the STT-MRAM device including a dielectric layer for generating electric field to assist switching.
Spin transfer torque magnetic random access memory (STT-MRAM) is a new class of non-volatile memory, which can retain the stored information when powered off. An STT-MRAM device normally comprises an array of memory cells, each of which includes at least a magnetic memory element and a selection element coupled in series between appropriate electrodes. Upon application of an appropriate voltage or current to the magnetic memory element, the electrical resistance of the magnetic memory element would change accordingly, thereby switching the stored logic in the respective memory cell.
FIG. 1 shows a conventional memory element for an STT-MRAM device comprising a magnetic reference layer 12 and a magnetic free layer 14 with an insulating tunnel junction layer 16 interposed therebetween, thereby collectively forming a magnetic tunneling junction (MTJ) 18. The magnetic reference layer 12 and free layer 14 have magnetization directions 20 and 22, respectively, which are substantially perpendicular to the layer plane. Therefore, the MTJ 18 is a perpendicular type comprising the magnetic layers 12 and 14 with perpendicular anisotropy. Upon application of a switching current through the perpendicular MTJ 18, the magnetization direction 22 of the magnetic free layer 14 can be switched between two directions: parallel and anti-parallel with respect to the magnetization direction 20 of the magnetic reference layer 12. The insulating tunnel junction layer 16 is normally made of an insulating material with a thickness ranging from a few to a few tens of angstroms. However, when the magnetization directions 22 and 20 of the magnetic free layer 14 and reference layer 12 are substantially parallel, electrons polarized by the magnetic reference layer 12 can tunnel through the insulating tunnel junction layer 16, thereby decreasing the electrical resistivity of the perpendicular MTJ 18. Conversely, the electrical resistivity of the perpendicular MTJ 18 is high when the magnetization directions 20 and 22 of the magnetic reference layer 12 and free layer 14 are substantially anti-parallel. Accordingly, the stored logic in the magnetic memory element can be switched by changing the magnetization direction 22 of the magnetic free layer 14.
A recent study by Wang et al. on perpendicular MTJ shows that the perpendicular anisotropy of magnetic layers in magnesium oxide (MgO) based MTJ structures can be changed by the voltage applied to the magnetic layers. See Wei-Gang Wang et al., "Electric-field-assisted switching in magnetic tunnel junctions," Nature Materials Vol. 11, 64-68 (2012).
In the test set-up of Wang et al. as shown in FIG. 1, a positive electric potential is applied to the MTJ 18 to drive electrons into the magnetic free layer 14 made of 1.6 nm thick Co40Fe40B20. When the insulating tunnel junction layer 16, which is made of 1.4 nm thick magnesium oxide (MgO), is sufficiently thick and electrical resistance across the MgO junction layer 16 is sufficiently high, the current density through the MgO junction layer 16 will be low. In this case, the magnetic reference layer 12, which is made of 1.3 nm thick Co40Fe40B20, and the magnetic free layer 14 adjacent to the MgO junction layer 16 effectively form a parallel plate capacitor with the MgO junction layer 16 acts as the dielectric. When a voltage is applied to the MTJ 18, electrical charges will accumulate in the two magnetic layers 12 and 14 like a capacitor, resulting in formation of an electric field 24 across the MgO junction layer 16. The applied positive voltage as shown in FIG. 1 causes the magnetic free layer 14 to have a negative potential, i.e. electron accumulation at the interface between the magnetic free layer 14 and the MgO junction layer 16. With increasing applied voltage and electron accumulation at the interface, the magnetic free layer 14 shows decreasing perpendicular anisotropy, which is reflected by decreasing coercivity field Hc. The decreasing of perpendicular anisotropy and corresponding coercivity field would facilitate the switching of the variable magnetization direction 22 of the magnetic free layer 14 from parallel to anti-parallel orientation. In contrast, electrons will be depleted at the interface between the magnetic reference layer 12 and the MgO junction layer 16 with increasing applied voltage, resulting in increasing perpendicular anisotropy and coercivity field for the magnetic reference layer 12. It should be noted that Wang's finding can only be used to help switching the variable magnetic moment 22 of the magnetic free layer 14 from parallel to anti-parallel orientation, not the other way, i.e. anti-parallel to parallel orientation.
A possible explanation of the observed changes in perpendicular anisotropy with electron accumulation/depletion at interfaces between magnetic free layer/MgO junction layer/magnetic reference layer as reported by Wang et al. may be that having increased amount of electrons at the interface between the magnetic free layer 14 and the MgO junction layer 16 allows more conductive electrons to fill the 3d-band of CoFe lattice and reduce the unpaired 3d-valence electron population, thereby making the broken-symmetry induced surface perpendicular anisotropy weaker and the magnetic free layer 14 magnetically softer. When 3d-electrons are depleted at the interface between the magnetic reference layer 12 and the MgO junction layer 16, electrons will be depleted first from paired 3d-electrons according to Hunt's Rules. As more 3d-electrons become unpaired in the magnetic reference layer 12, the surface perpendicular anisotropy thereof increases, making the magnetic reference layer 12 magnetically harder to switch by external field or spin transfer torque.
While a conventional MTJ having an MgO junction layer can exhibit the above-described electric field assisted switching effect, the effect is not significant because the MgO junction layer is thin enough to allow a relatively high density of electrons to tunnel therethrough, thereby minimizing the capacitive effect needed to generate electrons at the interface between the magnetic layer and the MgO junction layer. Increasing the MgO thickness can improve the capacitive effect but would also adversely increase the MTJ resistance. Moreover, the prior art method illustrated in FIG. 1 can only help switching a magnetic free layer from parallel to anti-parallel orientation, i.e. low resistance to high resistance state.
For the foregoing reasons, there is a need for an STT-MRAM device having MTJ memory elements that can be easily switched and a method for switching the memory elements between low and high resistance state.

Electric field assisted MRAM and method for using the same


An electrically controlled light modulator device comprises at least one cell, where two deformable dielectric layers meet at an interface, at least one of said layers consisting of viscoelastic relief forming gel. A first support electrode structure and a second signal electrode structures are arranged on separate sides of the dielectric layers in order to create an electric field passing through said layers and in order to create surface reliefs on the viscoelastic gel layer. According to the invention, a third enhancement electrode structure is arranged in the proximity of the first signal electrode structure. Applying enhancement signal voltage between the enhancement electrode structure and the signal electrode structure concentrates locally the electric field passing through the two deformable dielectric layers and therefore enhances the amplitude of the deformation of the viscoelastic gel layer.

Document WO 01/48531 discloses a display panel structure (see especially FIGS. 49 to 55) in the form of an array of cells each of which comprises two deformable dielectric layers, which meet at a common interface. One of said dielectrics can be air; the other is preferably polymer material acting as a relief forming gel. For each cell a first electrode structure, a support electrode structure is arranged on one side (below) of said dielectric layers and a second electrode structure, a signal electrode structure on the other side (above) of said layers, there being means for providing signals to the signal electrodes in order to create electric fields through the two dielectric layers and to further create surface reliefs on the gel surface at the interface of said two dielectrics. The periodical, sinusoidally varying reliefs created on the gel surface in each of the cells allows under the effect of light from a light source to create images on the display panel, which are viewable by the naked eye.
FIG. 1 illustrates schematically the general principle of physics, which can be observed in connection with dielectric substances and which is also utilized in the aforementioned optical display device. Dielectric substance can be defined as a substance in which an electric field may be maintained with zero or near zero power dissipation, that is the electrical conductivity of the substance is zero or near zero. An electric field E going through an interface where dielectricity changes, such as the interface between air and polymer, causes a force F onto the surface of the dielectric having the higher dielectricity constant. This ponderomotive force F is proportional to the square of the electric field E at that point. In the case of an interface between air and polymer, the ponderomotive force F acts onto the polymer surface into the direction of the air.
The electric field generated between a support electrode and a signal electrode and penetrating through the interface of the two dielectrics within a light modulator cell is inhomogeneous over the polymer surface; the electric field is strongest directly under a signal electrode and weakest in the middle between two adjacent signal electrodes. This situation is valid for any practical dimensions of the light modulator cells and corresponding devices. Therefore, the force acting onto the polymer surface is inhomogeneous as well and a deformation of the polymer surface causing the surface to deviate from a flat plane can be observed. An optimum situation would be such that maximum ponderomotive force is reached directly under the center part of a signal electrode and correspondingly no force is applied in the middle between two adjacent signal electrodes. This would provide maximum height for the surface relief, because it allows the maximum flow of the polymer material towards the area where the electric field is strongest. The concept of polymer flow is essential here, since most polymers are substantially uncompressible and therefore cannot simply expand in volume under the effect of an electric field.
FIG. 2 clarifies the aforementioned prior art solution by showing two adjacent pixels (cells) L,R in a possible pixel line of a display panel or corresponding light modulator device. Each pixel comprises several strip like signal electrodes 10 arranged parallel respect to each other on a substrate 11, which may be for example glass. FIG. 2 shows an end view of the signal electrodes 10 thus revealing only the width and mutual distance between the electrodes 10. A dielectric and viscoelastic gel material 12, for example polymer, is applied onto a support electrode 14 and facing the signal electrodes 10. A gap 13, for example an air gap, is left between the surface of the viscoelastic layer 12 and the signal electrodes 10. The usually transparent support electrode 14 providing AC or DC potential is preferably made of indium tin oxide (ITO), as is known in the art, on the surface of a transparent front plate 15. The front plate 15 may be for example glass.
The light may enter the structure depicted in FIG. 2 either through the front plate 15 or through the substrate 11. The device can be designed to operate either in transmissive or reflective mode depending on the light transmitting or reflecting properties of the various elements of the device.
In FIG. 2 the left pixel L is switched on by providing suitable voltage to the respective signal electrodes 10, whereas the right pixel R is switched off, that is no signal is fed to the signal electrodes 10 belonging to said pixel R. Arrows 16 marked for the left pixel L illustrate schematically the ponderomotive forces acting on the surface of the gel layer 12. Through proper selection of the signal electrode 10 dimensions (width) and mutual positioning (distance between adjacent and parallel electrodes) a sinusoidal surface structure, a surface relief can be created on the polymer gel 12 surface. Illuminating light onto the sinusoidal gel 12 surface in pixel L through the front plate 15 or substrate 11 refracts light into a slightly different direction than illuminating a plane gel surface in pixel R. By this means and using an optical blocking filter for the pixel in off state, a pixel can be electrically switched on and off.
The major shortcomings of the light modulators, like the display panels described in WO 01/48531, which are based on electrically controlled deformation of dielectric and viscoelastic materials may be associated with the practical difficulties in producing desired profiles for the gel reliefs. This further impairs the light modulating capabilities of the devices, for example the capabilities of individual pixels or cells.
With the goal of bringing display quality closer to that of a paper print, for example brightness and contrast of the displays must be further improved. In order to allow the use of display devices in small-size portable devices, the power consumption and thickness of the display devices should also be further reduced. To make mass production of portable devices possible, the manufacturing technology of the display devices should be simple in order to allow lower prices. The displays should also be fast enough to be able to display video or similar fast changing image content without degration of the image quality. The aforementioned requirements also apply on other light modulator devices than display panels. Other applications which may be based on the use of electrically controlled deformation of dielectric and viscoelastic transparent materials include, but are not limited to, electrically controlled diffractive or refractive lenses, or electrically reconfigurable optical waveguide couplers.

Enhancement electrode configuration for electrically controlled light modulators


A stroke limiting structure for use with a lift control system on an implement includes a reciprocating link operably connected to a hydraulic cylinder and to a lift wheel assembly on an implement frame section. The link is connected by a lost motion connection to depth gauging structure including gauge plates pivotally supported on a carrier. The plates are rotatable between disengaged and engaging positions without need for tools and are maintained together on the carrier to eliminate loose parts that could be misplaced or lost. The plates in the engaging position determine the lowermost position of the implement and provide a positive mechanical stop for the implement to eliminate depth control problems caused by cylinder leakage or the like. The lost motion connection eliminates unwanted movement of the plate carrier and facilitates gauge plate pivoting for depth adjustments.

1) Field of the Invention
The present invention relates generally to agricultural implements and, more specifically, to a depth control adjustment for cylinder operated lift system on an implement.
2) Related Art
Hydraulically operated lift structures on an agricultural implement often include hydraulic or mechanical stops to adjust position of the implements. For example, on tillage and seeding equipment frames, hydraulic depth controls of the type shown and described in U.S. Pat. Nos. 5,427,184 and 5,366,024 provide adjustable hydraulically operated down stops but require relatively complex linkage arrangements. Series cylinder hydraulic systems are also commonly utilized, but cylinder or other system leakage can adversely affect the depth setting in systems which require cylinder pressure to hold a preselected depth setting. Various mechanical stop systems, such as cylinder collars or donuts placed over the rod of a hydraulic cylinder provide a solid mechanical stop, and the number or size of the collars can be changed to adjust implement position. However, such adjustments are time-consuming, particularly if the cylinder is located in a position that is hard to access. Small changes in implement position are often difficult to achieve with many of the previously available, and individual adjusting components usually require a separate storage area and are easily lost or misplaced. Heretofore, providing a relatively simple and inexpensive mechanical stop that is reliable and yet easy to adjust for different implement positions has been a continuing problem.

Gauge structure for a cylinder operated depth control


Examples of an integrated active fiber optic temperature measuring device are disclosed. The integrated temperature measuring device comprises a fiber optic probe and an optoelectronic circuitry integrated into a single device which is then individually calibrated. The fiber optic probe has a fiber bundle with an active material at the tip of the probe. The optoelectronic circuitry is connected to the fiber optic probe. The optoelectronic circuitry includes a light source configured to provide an excitation light to the active material, a detector to detect the emitted light, a processing unit configured to determine a temperature based on a change in an emission intensity at a single wavelength range or the change in intensity ratio of two or more wavelength ranges, a lifetime decay, or a shift in emission wavelength peak of the emitted light, and a calibration means configured to calibrate the integrated active fiber optic temperature sensor.

Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
A fiber optic temperature sensor such as a phosphor thermometer is a device that uses luminescence emitted from the phosphor to determine the temperature of an object. Typically, thermographic phosphors when excited with light within a certain wavelength range, emit a light within a different wavelength range. Certain characteristics of the emitted light change with temperature including brightness, color, and afterglow duration. The response of the emitted light to temperature is monitored by various methods, such as analyzing the change in emission intensity at a single wavelength range or the change in intensity ratio of two or more wavelength ranges, lifetime decay, or shift in emission wavelength peak. Phosphor used for measuring the temperature of an object is either coated directly on the surface or placed within a probe and brought in contact with the surface, which is then illuminated with a light source and the temperature of the object is determined based on the response of the emitted light.
Standard fiber optic temperature measuring systems known in the prior art comprise a fiber optic probe with an active material at its tip which is connectable to an opto-electronics housing via a fiber optical connector. The fiber optic connector can be on the optoelectronics side or of the fiber optic probe side or both and allows separation of the probe from the optoelectronics. The ability to separate the probe and the opto-electronics in the known fiber optic temperature measuring systems is necessary for maintenance and installation purposes due to the size of the opto-electronics circuitry since such systems require a free space optical splitter which increases the size of the optoelectronics housing. The free space optical splitter usually incorporates 3 collimator lenses and a cold mirror to form an optical path for the excitation light directed to the active material and for the emitted light coming back from the active material. Thus, in the typical fiber optic temperature sensors the fiber probe and the opto-electronics are interchangeable, meaning if the probe is inaccurate the user can remove the probe and connect a new probe or vice versa if the opto-electronics needs maintaining or replacement the user can replace it by connecting a new opto-electronics housing. However, such interchangeable configurations (non-integrated configurations) of the fiber optic temperature measuring systems often provide inaccurate measurements. Current state of the accuracies achieved with the interchangeable fiber optic temperature sensors are in order of +/−0.5° C. The inaccuracy of the known interchangeable fiber optic temperature sensors is a combination of the opto-electronics converter inaccuracy, variability of optical path attenuation and inaccuracy contribution from inherent variability of photonic response of the active sensing materials. In optics there is an inherent problem with active material repeatability. The active materials are complex ceramics with variable stoichiometry resulting in non-repeatable temperature/decay dependency. Therefore, a very common problem in the fiber optic thermometer industry is maintaining batch to batch repeatability of the active material. This is a very difficult problem and usually involves sorting the sensing elements according to certain optical characteristics to select only those elements that satisfy the narrower, more accurate requirement, thus yielding fewer usable components that meet the requirements. A common approach to work around the problem of variation of active material is to have a "matching pair" of the fiber probe and the opto-electronics, meaning that a single particular optical sensor is calibrated together to match a particular opto-electronics circuit, however the accuracy in such case can only be achieved if that particular pair of fiber optic probe and opto-electronics is used for measurement. This is hard to achieve especially when deploying large quantities and the final user/customer needs to find the right matching pair. In addition, when the fiber optics or the opto-electronics fail and need to be discarded, the new (interchangeable) fiber optic probe or electronics will not meet specification and will not be a match to the other component.
In addition, excitation energy variation caused by variability of the optical path attenuation may also cause accuracy limitations.

Integrated active fiber optic temperature measuring device


An indicator indicates a vehicle state value in accordance with a rotational position between a zero position and a maximum position. A step motor rotationally drives the indicator on application of a drive signal in accordance with an electrical angle to a field winding. A control unit that controls the electrical angle of the drive signal applied to the field winding performs a leave-zero control operation which varies the electrical angle to rotate the indicator from the zero position to the maximum position and determines presence or absence of abnormal rotation of the indicator based on the electrical angle at the time of detecting the stopping of the indicator during the leave-zero control operation.

Conventionally, an indicating instrument for a vehicle has been known which rotationally drives an indicator with a step motor to indicate a vehicle state value in accordance with the rotational position of the indicator between a zero position and a maximum position. For example, Patent Literature 1 discloses an indicating instrument for a vehicle which applies drive signals in accordance with electrical angles to the field windings of a step motor to rotationally drive an indicator.
In the indicating instrument for a vehicle disclosed in Patent Literature 1, the indicator is stopped at a zero position using a stopper mechanism. In this manner, the electrical angles when the indicator is rotated to the zero position are automatically updated to allow the electrical angles of the drive signals to be precisely controlled.


The invention provides a base for a vending machine having a removable cash box slidably received within the base for receiving coins or tokens deposited by the coin mechanism into the base compartment. In the preferred embodiment the base includes a base frame having a reinforcing bridge bracing the front and rear portions of the base frame. The bridge resists deformation of the base frame, provides a secure structure for receiving the latch from the box lock, and provides a means elevated above the base floor for affixing a center rod which secures the components of the vender together, allowing the cash box to occupy virtually the entire floor area of the base.

Vending machines are popular for many merchandise-dispensing applications. In particular, bulk venders, colloquially known as "gum ball machines", are widely used for dispensing gum balls and other small articles. Bulk venders are intended particularly for use in unsupervised public areas, and as such must be designed to resist tampering, theft and vandalism.
A typical bulk vender has a hopper assembly comprising a transparent globe which functions as a merchandise storage bin, seated over a dispensing wheel which revolves in a hopper to dispense a preset amount of merchandise to the user through a dispensing chute. The hopper assembly is located over a body which in turn sits on a base comprising a floor circumscribed by a base frame, defining a secure base compartment. A coin mechanism is mounted in the body, with the coin slot and handle accessible from outside the body of the vender.
The handle can be rotated when one or more coins of the correct denomination, or properly configured tokens, are inserted into the coin slot. This in turn rotates a gear meshing with a toothed edge of the dispensing wheel within the base compartment, such that rotation of the coin mechanism causes the dispensing wheel to revolve and dispense merchandise through a dispensing chute. As the coin mechanism rotates the coin or token is deposited into a cash box protected within the confines of the base compartment. This bulk vender design is well known to those skilled in the art.
In a typical bulk vender the components of the vender are locked together by a center rod affixed to the base floor by threaded engagement into a socket, extending in turn up through the center of the base compartment, the dispensing wheel and the globe and locked into a tubular lock that threads onto the end of the center rod and nests in a central recess provided in the top, effectively securing all components of the vender together between the base and the top.
In order to change or replenish merchandise in the globe only the lock and the top need to be removed, exposing the top opening of the globe. However, to empty the cash box from within the secure base compartment it is necessary to remove the lock, the top and the entire hopper assembly, exposing the open top of the body. This is a time consuming task and, particularly where the globe is relatively well stocked with merchandise, these components can be quite heavy and difficult for an operator to handle.
In some situations there may not be a convenient location to stow these components while the cash box is being emptied. Moreover, removing and replacing the hopper assembly while the globe is stocked with merchandise can damage the merchandise, as the center rod (which has a threaded upper end to engage the lock) abrades against the merchandise in the globe.
Further, because the center rod extends fully to the base floor centrally within the base compartment, there is a limited amount of room available within the base compartment for a removable cash box. A removable cash box must be dimensioned to occupy less than one-half of the floor area of the base compartment, so that it can be easily removed, emptied and replaced without interfering with the center rod. As such, most of the space within the base compartment goes unused. The small size of the cash box substantially limits the number of coins or tokens which the cash box can hold, and as the cash box fills to capacity coins or tokens can pile up and block the coin ejection portion of the coin mechanism, causing it to jam. This means that the vender must be serviced frequently, increasing the cost to the operator.
It would thus be advantageous to provide a removable cash box which is accessible from outside the base compartment without having to remove the hopper assembly from the vender. However, because a bulk vender is likely to be situated in a location where its use is unsupervised, such a system must be designed to resist unauthorized access into the base compartment. Merely providing an opening in the body or the base would reduce the structural integrity of the vender and compromise the security of the base compartment.
It would also be advantageous to provide a cash box which utilizes as much as possible of the available floor area within the base compartment, to maximize the capacity of the cash box and commensurately decrease the frequency of servicing required for the vender.

Bulk vender base with removable cash box


The present invention automatically detects the onset of instability of an elevator active ride control system and activates a system shutdown if it occurs. As an elevator car is guided along rails by guide elements, a plurality of sensors mounted on the car measure vibration transverse to a direction of travel. The signals from the sensors are input to a controller which in turn produces a controller output signal. This signal is used to energize an actuator positioned between the car and the guide elements and thereby dampen the vibrations acting on the car. As instability sets in, a controller signal increases. The controller signal is monitored by a comparator such that the actuator is deactivated if the controller signal becomes greater than a predetermined value.

U.S. Pat. No. 5,896,949 describes an elevator installation in which the ride quality is actively controlled using a plurality of electromagnetic linear actuators. Such a system is commonly referred to as an active ride control system. As an elevator car travels along guide rails provided in a hoistway, sensors mounted on the car measure the vibrations occurring transverse to the direction of travel. Signals from the sensors are input to a controller which computes the activation current required for each linear actuator to suppress the sensed vibrations. These activation currents are supplied to the linear actuators which actively dampen the vibrations and thereby the ride quality for passengers traveling within the car is enhanced.
The controller comprises a position controller with position feedback and an acceleration controller with acceleration feedback. The position controller is rather slow and its output is limited to a level so as not to cause overheating of the actuators. The output from the acceleration controller, however, is not restricted and can produce large amplitude resonance forces at the actuators.
All closed loop controllers can become unstable if feedback gain is too high. Indeed, the acceleration controller can become unstable very easily since the feedback gain margin that leads to stability can be as low as a factor of two. Hence, simple hardware failures or software errors can easily cause instability of the acceleration controller. An unstable situation would not necessarily harm the safety of any passengers traveling in the elevator car, but undoubtedly causes a considerable amount of discomfort for them. Since the active ride control system is solely designed to improve passenger comfort, an unstable and vibrating system would therefore defeat the purpose of, and completely undermine user confidence in, the active ride control system.

Elevator vibration damping apparatus and method


Processing of a pixel in a digital image includes performing inverse halftoning on the pixel with respect to a local pixel neighborhood; and performing selective sharpening on the inverse halftoned pixel with respect to the local pixel neighborhood.

Document processing systems are capable of scanning documents and processing the resulting digital images. The processing might include image display (e.g., printing), compression, page segmentation and recognition, and optical character recognition (OCR). Compression reduces the size of the digital images, which reduces the cost of storing and transmitting the digital images. Page segmentation and recognition may be performed to separate natural features (e.g., photos) from text and other graphical features in compound documents. OCR may then be performed on text.
Scanned document images can be distorted with respect to the original documents. Scanning distortion can be caused by scanner smoothing and integration, electronic noise, and inaccurate measurement of white level. These scanning distortions can blur edges, and create noise and artifacts in digital images. Perceptible noise and artifacts can degrade image quality. Perceptible and imperceptible noise and artifacts can reduce compressibility. Reducing compressibility can increase the cost of storing and transmitting the images. The noise and artifacts can also increase the error rate of processing routines such as OCR.
The way in which the documents were created can also lead to distortions in the scanned image. For example, a printed document might contain halftone regions. Distortions such as Moire patterns can arise from interaction between halftone patterns and a scanner. The Moiré patterns and other halftoning noise artifacts can also degrade image quality and reduce compressibility.
Bleed-through artifacts can occur if a document is printed on both sides. When one side of a double-sided document is scanned, features on the opposite side of the document can be captured. These features appear as artifacts in the scanned digital image, manifested as phantoms of text characters and other dark features from the other side. The bleed-through artifacts can also degrade image quality and reduce compressibility.

Restoration and enhancement of scanned document images

Hewlett-Packard Development Company, L.P.


A photographing optical lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element has an object-side surface being convex in a paraxial region thereof. The second lens element has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The third lens element has an object-side surface being convex in a paraxial region thereof. The fourth lens element has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The fifth lens element has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof.

1. Technical Field
The present disclosure relates to a photographing optical lens assembly, an image capturing device and a mobile terminal. More particularly, the present disclosure relates to a compact photographing optical lens assembly and an image capturing device applicable to a mobile terminal.
2. Description of Related Art
In recent years, with the popularity of mobile terminals having camera functionalities, the demand of miniaturized optical systems has been increasing. The sensor of a conventional optical system is typically a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. As the advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact optical systems have gradually evolved toward the field of higher megapixels, there is an increasing demand for compact optical systems featuring better image quality.
Other conventional compact optical systems with five-element lens structure enhance image quality and resolution. However, the arrangement of the axial distances between each lens element is not favorable for keeping its optical system compact. Furthermore, the second lens element has its image-side surface being concave in a paraxial region thereof; therefore, it is not favorable for reducing the incident angle of the peripheral region. It is also not favorable for illumination and concentrating the lights of the peripheral region.

Photographing optical lens assembly, image capturing device and mobile terminal


Heat can be supplied effectively to a porous member of a vaporizer apparatus so that a vaporizing operation can be carried out smoothly and efficiently. The vaporizer apparatus includes a vaporizer section having a porous member including a liquid receiving surface and a vapor discharge surface. A feed supply section supplies a liquid feed material to the liquid receiving surface of the porous member. A heating medium passage is in thermal contact with the porous member. A heating medium supply system flows a heating medium of a temperature higher than a vaporization temperature of the liquid feed material through the heating medium passage.

1. Field of the Invention
This invention relates in general to a vaporizer apparatus which is used, for example, in chemical vapor deposition of thin films from liquid feed material, and relates in particular to a liquid feed vaporizer apparatus for vaporizing such high dielectric thin film forming materials as barium/strontium titanate.
2. Description of the Related Art
In recent years, significant progress has been made in the field of high density integration of semiconductor electronic circuits in anticipation of achieving giga-bit-capacity DRAMs to overtake the currently available mega-bit-capacity DRAMs. For obtaining the high capacity dielectric thin films necessary to produce such DRAM circuits, the currently used dielectric materials such as silicon oxide and silicon nitride films having dielectric constant less than 10 are to be superseded by metallic thin film materials such as tantrum pentaoxide (Ta.sub.2 O.sub.5) having a dielectric constant in the range of 20, barium titanium oxide (BaTiO.sub.3) or strontium titanium oxide (SrTiO3) having a dielectric constant in the range of 300, or barium strontium titanate which is an admixture of the afore-mentioned compounds.
As a method of growing thin films from such materials, chemical vapor deposition (CVD) is favored. In this case, it is necessary that, a gas-phase feed material be supplied steadily on a substrate material held in a reaction chamber. In order to stabilize the vaporization characteristics, the feed gas is derived by heating for vaporization a liquid source produced by dissolving materials such as Ba(DPM).sub.2 or Sr(DPM).sub.2, which are solid at normal temperature, in some organic solvent such as THF.
It is extremely difficult to stably vaporize feed materials of highly dielectric materials described above because: (1) vaporization and decomposition temperatures are close together; (2) a difference exists in the vaporization temperatures between the film material and the organic solvent; and (3) the vapor pressures are all very low. For example, for a liquid feed made by dissolving Ba(DPM).sub.2 or Sr(DPM).sub.2 in THF, the liquid phase of the solvent ranges in the region marked as "a" in FIG. 6, and the liquid or solid phase of the material ranges in "a+c". Therefore, when raising the temperature of the liquid through the region marked "c" to vaporize the liquid feed which is in "a", there is a danger that only the solvent is evaporated, causing the film material to precipitate out and resulting in plugging of the passage or degradation in the feed quality due to compositional changes.
Therefore it is generally considered that, when vaporizing a liquid feed material, it is necessary to rapidly heat the liquid to bring it quickly to the high temperature region. A known type of vaporizer apparatus utilizes a technology of first preparing atomized mist with the use of an ejector nozzle or ultrasonic vibrator, and then heating the mist in a high temperature region to produce a vapor.
However, in the conventional type of vaporizer apparatus presented above, a porous member loses heat due to the heat of vaporization of the liquid feed dispersed therein, and if a local low temperature zone should be created, it may cause a clogging of the porous member. Therefore, it is necessary that a fairly large amount of excess heat be supplied to the porous member. In the conventional vaporizer apparatus, the heat to the porous member is supplied externally, and the center of the porous member is heated primarily by the heat conducted through the porous member itself. Therefore, the supply of heat to the interior of the porous member tends to be insufficient, and consequently the vaporizing efficiency is lowered due to such problems as clogging in the interior of the porous member.
For the type of vaporizing process in which only the lower temperature limit is important, the exterior temperature of the porous member is heated to a sufficiently high temperature so that the interior region of the porous member can reach the required temperature. However, for certain types of liquid feed material, excessive raising of the external temperature may cause a possible decomposition or degradation of the liquid or evaporated feed material. For such materials, the presently employed method cannot be employed because the required range between the upper and lower temperature limits is too narrow.