Abstract: This invention enables a user to locate a missing remote control unit for an appliance, such as a television set, by causing the missing unit to emit an alarm. The television set includes a transmitter which is controlled by a switch mounted on the television cabinet. The remote control unit includes a receiver, capable of detecting a signal from the transmitter. The receiver activates an alarm, which can be audible, visible, or both. When the switch is depressed, and if the remote control unit is within range, the alarm will be activated, and the unit is easily located. The transmitter can be controlled by a timer which governs the period during which the alarm sounds. Also, the transmitter can be connected to a lamp, or other indicator, to show the user when the transmitter is operating. The transmitter and switch can be built into the television cabinet, or they can be housed in a separate unit which is attached to the cabinet.

Abstract: In an error diffusion halftone screen generation system, improved image smoothness in the highlight and shadow areas is obtained by calculating the distance to the nearest previously generated output dot. The square of the distance to the nearest previously generated dot is used as a bias value to effectively modulate the error diffusion threshold. The resulting output provides a halftone with a more uniform texture in the highlight and shadow areas of the screened image. The resulting pattern resembles the pattern of dots produced by tightly packing imaginary circles in the image plane, and placing an output dot at the center of each such tightly packed imaginary circle.

Abstract: Thin layers of aluminum and palladium are deposited and annealed to produce aluminum-palladium alloy. The surface of the alloy is exposed and treated with an aluminum enchant to produce a catalytic surface. The catalytic surface is used for electroless plating of nickel, providing excellent plating uniformity and adhesion, as well as a reduced plating induction time. Several variants of the basic method are shown.

Abstract: A dynamometer for a snowmobile includes a pair of driver wheels which replace the tension idler wheels so as to contact the inside of the snowmobile track. The regular snowmobile tension idler wheels are removed, and the driver wheels are positioned on the idler wheel axle. In the alternative, the dynamometer is attached to the existing tension idler wheels by a coupling plate. In the alternative embodiment, the tension idler wheels are configured for power take off by including pins forming a quick connect coupling mechanism. The quick connect coupling mechanism permits the dynamometer to be connected to the snowmobile without having to remove and replace the tension idler wheels with a different pair of driver wheels. A jack is provided to lift the snowmobile track clear of the ground by applying a lifting force between the ground and the tension idler wheel axle. The dynamometer and jack are integrated so as to share common components.

Abstract: A wireless communication system combines time and space diversity to reduce fading and simplify receiver design. In particular, a data packet which carries digital telephone traffic, is transmitted at three different times from three different antennas. The mobile subscriber receiver thus receives the same data packet at three different times from three different antennas, and uses the best data packet or combination of the data packets to reduce the effects of fading. A transfer station receives a time division multiplex multiple access (TDMA) signal from a base station carrying telephone data packet traffic to form three data packet repeats at spatially diverse antennas locations. The transfer station further modulates a code division multiple access (CDMA) system using a TDMA signal which links the mobile subscriber receiver to the transfer station. Each data packet received at the transfer station is thus retransmitted at three different times to the mobile subscriber station on a CDMA link.

Abstract: A method for determining degrees of freedom of an object, and in particular, to a device for determining up to six degrees of freedom of a head mount display and a handle. A first camera is attached to a head mount display and senses an optically modulated target. The first camera's video output signal is processed with a digital computer to determine the position and orientation of the head mount display. A second camera is attached to a head mount display and senses an optically modulated target attached to a handle. The second camera's video output signal is processed with a digital computer to determine the position and orientation of the handle.

Abstract: A method for determining up to six degrees of freedom of a camera relative to a reference frame comprises sensing an optically modulated target with the camera and processing the camera's video output signal with a digital computer. The target may have a single pattern, multiple patterns, or patterns of varying size. Multiple targets may also be used. A very wide field of view camera may be used in conjunction with a method for removing geometric distortion from the camera's view. Target patterns may be transmissive, reflective, or retroreflective, or may actively emit light. Asymmetric patterns are used to eliminate ambiguity in the recovery of the degrees of freedom.

Abstract: The disclosed system relates to metered use cryptographic systems, and particularly to a data package and system operation for effecting metered purchases of encrypted data from a local encrypted database. A local CD ROM encrypted database includes one or more data package records containing one or more message keys encrypted under a database key, and one or more data packages encrypted under said message keys. The user decrypts portions of the database, and the data used is metered locally and recorded as a stored data usage record. The local stored data usage record is reported by telephone modem or other telecommunications link from a remote user terminal, such as a host personal computer containing a remote cryptographic control unit, to a cryptographic operations center.

Abstract: A data transmission system for use in a mass memory system includes a unique EDAC which corrects all single component errors and detects all double component errors. High speed operation permits use of the EDAC on address and control lines as well as on data lines. In memory systems which use virtual memory addressing, further efficiency and economy is achieved by incorporating a partial implementation of the EDAC encoding in the same virtual memory address translation unit in which virtual memory address are calculated. False indications of error are avoided by ANDing the signals which indicate the location of an error, with an inclusive OR of all the bits which indicate the existence of an error but not the location of the error. In such manner, the error location signals are set to zero when the error detection bits indicate that there are no errors.

Abstract: A type of neural network called a self-organizing map (SOM) is useful in pattern classification. The ability of the SOM to map the density of the input distribution is improved with two techniques. In the first technique, the SOM is improved by monitoring the frequency for which each node is the winning node, and splitting frequently winning nodes into two nodes, while eliminating infrequently winning nodes. Topological order is preserved by inserting a link between the preceding and following nodes so that such preceding and following nodes are now adjacent in the output index space. In the second technique, the SOM is trained by applying a weight correction to each node based on the frequencies of that node and its neighbors. If any of the adjacent nodes have a frequency greater than the frequency of the present node, then the weight vector of the present node is adjusted towards the highest-frequency neighboring node.

Abstract: A variable Venturi slide includes a beveled edge at an oblique angle to lower surface of the slide and air flow, and an auxiliary hole having an opening on the beveled edge communicating between the air flow and the interior of the variable Venturi slide. By being located on the beveled edge, the opening of the auxiliary hole is effectively kept out of the high velocity low air pressure air stream at lower air velocities during partial throttle conditions. The auxiliary hole bleeds vacuum from the interior of the variable Venturi slide, picked up by the other lift hole located on the bottom of the slide, and slows the slide lift rate. The slide stays down or rises very slowly under conditions in which a conventional prior art slide would be starting to rise at a linear rate. At higher air velocities, when the throttle plate is opened quickly or operated at near wide open conditions, the opening of the auxiliary hole adds vacuum to the interior of the slide, and increases the slide lift rate.

Abstract: A photoresist (18) is exposed through a design-independent high resolution reticle (20), producing a high resolution image of exposed resist (18A). Photoresist (18) is exposed for the second time through a design-specific low-resolution reticle (24), exposing selected portions (18D) of previously unexposed resist. The remaining portions (18B) of previously unexposed resist form a design-dependent high resolution image. After development of photoresist (18), its unexposed portions (18B) are removed, producing openings (26) in photoresist (18), that can be transferred to underlying material (36), for example by etching openings in that underlying material (36), thereby transferring the design-dependent high-resolution image to it. Since the design-independent high resolution reticle (20) can be prefabricated ahead of time and used to produce many designs with different functions, the above double-exposure method is suitable for fabricating design-specific high resolution features, e.g.

Abstract: A cryptographic communications system includes a method and apparatus for sending and receiving a plurality of encrypted signal packets in a system for metering the use of encrypted information. Plural packet communication between a user terminal containing a remote cryptographic control unit and a cryptographic operations center typically includes uploading usage records and downloading credit. Plural packet messages are protected to detect alterations in the form of packet reordering by cross linking data cryptographic codes and message authentication codes (MAC). In particular, a first cryptographic code key is used to encrypt a first plurality of signal packets. A second cryptographic code key is used to encrypt the encrypted first plurality of signal packets to form an appended MAC. The initial vector for computing the MAC for a given packet is the last encrypted data block of the previous packet encrypted with the first cryptographic code key.

Abstract: A wireless communication system combines time and space diversity to reduce fading and simplify receiver design. In particular, a data packet which carries digital telephone traffic, is transmitted at three different times from three different antennas. The mobile subscriber receiver thus receives the same data packet at three different times from three different antennas, and uses the best data packet or combination of the data packets to reduce the effects of fading. A transfer station receives a time division multiplex multiple access (TDMA) signal from a base station carrying telephone data packet traffic to form three data packet repeats at spatially diverse antennas locations. The transfer station further modulates a code division multiple access (CDMA) system using a TDMA signal which links the mobile subscriber receiver to the transfer station. Each data packet received at the transfer station is thus retransmitted at three different times to the mobile subscriber station on a CDMA link.

Abstract: A code excited linear prediction speech communication system includes a ternary codebook of innovation sequences. The ternary codebook is formed as the sum of first and second binary codebooks containing binary codevectors. Code sequences C.sub.k, in the ternary codebook are constructed from the set of values, {-1,0,1}. To form the ternary codebook, one binary codebook has the binary codevector values {0,1}, and the other binary codebook has the binary codevector values {-1,0}. The sum of one binary codevector from each binary codebook forms a ternary codevector. The present codebook structure permits several efficient search procedures for an optimum innovation sequence. In particular, the binary codevectors may be searched using a given fidelity criterion function in order to find an optimum ternary codevector representing the optimum innovation sequence.

Abstract: Thin layers of aluminum (13) and palladium (12) are deposited and annealed to produce aluminum-palladium alloy (14). The surface of the alloy (14) is exposed and treated with an aluminum etchant to produce a catalytic surface (15). The catalytic surface is used for electroless plating of nickel, providing excellent plating uniformity and adhesion, as well as a reduced plating induction time. Several variants of the basic method are possible.

Abstract: A method and apparatus for automatically correcting the tone values of a digitally stored image includes compiling a histogram of the relative occurrence of gray values in the stored image in memory. The histogram is processed by adding a constant, taking the square root, and digital filtering. The processed histogram is numerically integrated and then normalized to form a tone correction function. The present tone correction method may be used to tone correct color images by applying separate tone correction functions generated for each of the three color planes independently, or in the alternative, by applying a composite tone correction function corresponding to the average of histograms of the respective individual color planes. A switch is provided to allow the operator to view the results of both methods of automatic tone correction for color images, and choose the best resulting image.

Abstract: A bar code reader includes a first and second memory arrangement in which a two dimensional image containing the image of a bar code symbol at a random location and orientation is stored in a first memory. Thereafter, the contents of the first memory is processed by a specialized controller to determine whether any portion of the stored image is likely to contain a bar code symbol, and if so, at what location. If a bar code symbol is located, then the portion of the image stored in the first memory which has been identified as likely to contain a bar code symbol is transferred to a second memory. In the second memory, the stored image is processed by a digital signal processor in order to orient, filter and scan the stored bar code image.

Abstract: A data input device and method for producing signals corresponding to symbols, comprises: at least one manually actuatable switch having a home state and manually actuatable from the home state to one of a set of first states and manually actuatable from the set of first states to one of a set of second states including the home state. A first signal corresponding to a transition from the home state to a selected one of the set of first states is produced and a second signal corresponding to a transition from the selected one of the set of first states to a selected one of the set of second states is produced. An output signal representing one symbol is produced in response to the first and second signals.

Abstract: A halftone screen, at a desired screen angle and ruling, is generated by concatenating strips of an ideal angled screen pattern. Artifacts are reduced by aligning the vertical boundaries between adjacent strips. In one embodiment, a screen pattern is generated by storing a plurality of double width strips from an ideal angled screen pattern, and concatenating a sequence comprising a portion of each double width strip in a selected order. Regardless of the choice of starting point in the strip for each successive scan line, a sufficient portion of the double width strip is clocked out until the edge of the strip aligns with the strip above it. In a second embodiment, strips of a rational angled screen are concatenated to approximate an irrational angled screen. Errors which accumulate with each successive pixel are corrected by occasionally jumping to a new point in the strip.