Abstract: An apparatus for controlling audio signals having pulse code modulation (PCM) data and methods of operating the same result in efficient modulation of the audio signals. The apparatus for controlling audio signals comprises a PCM data input register configured to store the PCM data. A shift register is coupled to the PCM data input register configured to serially shift the PCM data. A PCM data output register is coupled to the shift register configured to store modified PCM data. An audio magnitude controller is coupled to the shift register configured to control serial shifting of the shift register to provide the modified PCM data.

Abstract: This invention provides a method for compositing a source image and a destination image using a mask image to produce a result image in a digital image processing system. The method is, on a pixel-by-pixel basis, using the mask image to select between the source and destination images: where a black color value for a mask pixel selects the color value of the corresponding pixel of the source image; and a white color value for a mask pixel selects the color value of the corresponding pixel of the destination image; and where an intermediate color value for a mask pixel selects a weighted average between source and destination pixel color values. The calculations of the weighted average color value are done in color space, such as on a color component by color component basis. The result image can be displayed or stored for further use. This method can be described in boolean expression according to the formula:result=((1-mask)*source)+(mask*destination).

Abstract: This invention relates to an apparatus and method for reducing the transmission of data on a data communications network by obtaining data from a cache rather than by transmitting the data. This method maintains an indexed cache of data from previous transmissions. Then, when duplicate information is to be transmitted, it can be replaced by a flag and an index to the cached data. This reduces the amount of data to be transmitted and increases the apparent rate of transfer.

Abstract: A hidden, releasable latch for a molded plastic enclosure having a first panel abutting a second panel along a seam. The first panel has a pressure bump on its inside surface a first distance from the seam, and a projecting tang on its inside surface at a further distance from the seam. The second panel has a tab from its inside surface projecting inside, parallel and spaced from the inside surface of the first panel, the tab contacting the pressure bump, and capturing the projecting tang in a hole within the tab. The tab is flexible enough for slight deflection during the capturing of the tang by the hole during an assembly process, and the releasing of the tang by movement of the tab from pressure from the pressure bump during a disassembly process.

Abstract: A method for clock synchronization for receiving pulse position encoded signals in which a clock signal defines slots or windows of time in which to receive pulse signals. The signal received within a slot is measured to obtain a value representing the amount of signal received within that slot. The values from adjacent slots are compared to determine into which slot the signal most fully fits, and to determine a clock correction value which would change the phase of the clock to make the slots more accurately center on the received pulses. During a time period in which clock adjustment will not affect received pulses, the clock correction value is applied to the clock. In a preferred form, the measurement of pulses, comparison between slots, and clock correction are all performed digitally. A list of energy values is maintained for all slots within a frame, so that the maximum energy value can be selected for assigning a pulse position to a slot within that frame.

Abstract: A pulse modulated infrared data communications link including a transmitter and receiver in which the data to be sent is encoded as a biphase modulated signal having bit-cell and mid-cell transitions. Each transition is encoded as a narrow pulse in a pulse modulated signal. The pulse modulated signal is used to activate an infrared optical transmitter for generating pulsed optical signals. At a receiver, an optical detector converts pulsed optical signals into pulsed electrical signals. The pulsed electrical signals are amplified and filtered and evaluated by a comparator to generate a pulsed digital signal. The pulsed digital signal is processed by a logic circuit to generate a biphase encoded signal for transmitting on a serial data line.

Abstract: A head and media for optical data storage with a media in which a partially light transmissive recording layer and a reflective layer are located on opposite faces of a transparent substrate layer. The head emits a light beam which passes through the recording layer, transits the substrate layer, reflects internally off the reflective layer, transits the substrate layer in the opposite direction, and comes to focus on the recording layer. This optical path is used for reading and writing. Two of these optical media, placed back to back, with recording layer faces outward, can be used to form a double-sided media with read and write capability from either side. In a magneto-optical system, since the recording layer is near the outer surface, both the optical and magnetic heads can be located and moved as a single unit, increasing the speed and reliability and reducing the cost.

Abstract: A self-terminating coaxial tap connector for use with an external termination element has two oppositely directed coaxial connector sockets having conncected center conductors and connected surround shields, the connected shields having a mounting tab for attachment to a printed circuit board. Within the connected shields is a secondary conductor parallel and spaced from the center conductors. Within each socket, at an end of the secondary conductor near the end of a center conductor, is a movable switch element connected to the secondary conductor and having a first switch position in contact with the center conductor when the socket is open, and having a second switch position detached from the center conductor when a mating plug connector is coupled to the socket, the switch element being moved to the second switch position by abutment with the mating plug connector.

Abstract: An error reducing raster scan method for a raster scan device having multiple simultaneous scan lines, the method including the steps of separating scan lines to be placed adjacent to each other into different scan groups, so that no two scan lines to be placed adjacent to each other are in the same scan group, and a scanning a set of scan lines from a different one of the scan groups on each scan across the area.

Abstract: A self-terminating coaxial connector for installation on the end of a coaxial cable has a coaxial connector plug with a center conductor surrounded by a shield, and within the plug, a switch contact spring and a termination circuit element. The switch contact spring is mounted within the shield substantially parallel to and separated by a spaced gap from the center conductor. The switch contact spring has an end near the center conductor and open end of the plug folded back to cross the spaced gap and movably contact to the center conductor. This movable contact is moved out of contact to the center conductor by coupling of the plug to a mating socket connector. Also within the plug is a termination circuit element connecting from the switch contact spring through the termination circuit element to the shield. This self-terminating plug design has reduced signal reflection and signal radiation problems, and has a simplified mechanical assembly within the connector.

Abstract: A stacking and orientation independent multiple contact plug and socket electrical connector has a central connector body with a "plug" extending outward on one face, and a "socket" recessed inward on an opposite face. The plug and socket are aligned along a common axis, but are on opposite faces of the central connector body. The plug is an electrically insulated post extending outward from the central connector body and having multiple electrically conductive circular contact rings encircling the post. The socket is a cylindrical recess into the central connector body designed to accept the plug of another similar connector. The socket has multiple electrical wiper contacts spaced along an electrically insulating inner wall of the recess for contacting to the circular contact rings of a post.

Abstract: A full-spectrum stereoscopic display system with a tiled display image of alternating tiles from first and second full-spectrum images of a stereo pair of images is covered by an identically tiled polarized mask, with alternating tiles of said polarized mask being cross polarized. When viewed through cross polarized viewing glasses, separate views will appear for the left and right eyes of the viewer.

Abstract: A self-correcting synchronization signal for a communication interconnect which connects multiple units, the synchronization method including the steps of: waiting for a predetermined period of time until the next synchronization signal is due (nominal cycle period); waiting a further period of time for the absence of communications on the interconnect among any of the units, and forming a count of the passage of time during this delay (start delay); forming a synchronization signal including the count of the delay time; and sending the synchronization signal on the interconnect. Also according to this invention, a unit receiving the synchronization signal on the interconnect can update its count of time by the predetermined period of time plus the count of the delay period of time.

Abstract: A method and apparatus for verifying a file stored separately from a computer to be identical with a previous version of the file, before using the file. This verification is done by following a defined procedure to generate a first identifier based on the contents of the previous version of the file, storing this identifier locally on the computer, and storing the file at a separate storage location. Then, at a later time, an unverified second file is retrieved from the separate storage location, the same defined procedure is followed to generate a second identifier, and the first and second identifiers compared to identify a match that verifies the integrity of the second file.

Abstract: A printer using meltable solid ink pellets loaded into a reservoir in which a holder with an attached solid ink pellet is inserted through a doorway for access to the reservoir and a release mechanism within the reservoir releases the ink pellet from the holder by engagement of the ink and release mechanism. The holder surrounds the pellet on all but one end and includes keyed projections on the holder for matching to keyed slots on said doorway, such that only a matching keyed holder will pass through said doorway. The keyed projections on the holder are used to open the doorway. The release mechanism includes a bore for receiving and restraining the pellet against rotation of the holder, or can include a thin chisel for severing the connection of the pellet to the holder.

Abstract: A self-terminating network of stations connected by coaxial cable segments with each cable segment having ends with cable connectors for coupling to matching device connecters. Each connector has a switchable termination circuit de-activated by coupling to a matching connector. An uncoupled connector will serve as a terminator. The device connector can be a tap connector for mounting on a printed circuit board, for minimizing the length of the tap, and reducing the distrubance to an attached coaxial cable network.

Abstract: A multiple contact coaxial shell connector combines coaxial, shielded, and multiple contacts in a single connector which need not have angular orientation before mating. The connector is formed by a post, shell, and connector body. The post is formed as an insulating contact-carrying post having multiple electrical contact bands spaced along the length of the post. The post is surrounded by one or more shells, where each shell is formed as an insulating contact-carrying shell coaxially encircling and spaced from the post, each shell having multiple electrical contact rings spaced along the length of the shell. The shell can also contain a encircling shielding layer. The post and shell are mounted at one end to a connector body, leaving the other end open for access to the multiple contacts by a matching socket. The socket has complementary recesses to mate to the connector post and shell, and has leaf spring contacts to contact the multiple contact rings and bands of the post and shell.

Abstract: A print head position control system for a printer in which a print head moves along a track and in which a light source illuminates along the track and a photodetector receives the light to produce a control signal in proportion to the position of the print head in relation to the light. A print head mount electromechanically adjusts the position of the print head in response to the control signal, so that the path of the light automatically controls the print head path along the track.

Abstract: A circuit which provides additional drive current during substantially the entire transition of an output signal from a logical one to a logical zero state, thereby causing the pulldown transistor in the TTL output stage to rapidly turn on, providing increased switching speed between logical one and logical zero output state for a given power consumption. Alternatively, for a given switching speed, power consumption is reduced.

Abstract: A switching voltage regulator is stabilized against changes in input voltage by suppressing the increase in loop gain due to increased input voltage. The reduction of loop gain is achieved by use of a modified triangle waveform which is compared to an error signal to switch the regulator output stage.