Patents Assigned to Tandy Corporation
  • Patent number: 5355082
    Abstract: An automatic transistor checking method is provided, whereby an unknown, bipolar transistor may be typed, pinned and checked for forward DC gain, H.sub.fe. The method is suitable for portable instruments, because the method uses little battery current to perform the H.sub.fe measurement. The method automatically determines transistor type (NPN or PNP) and pinout, making it suitable for quick checking of batches of unknown devices.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: October 11, 1994
    Assignee: Tandy Corporation
    Inventors: Paul T. Schreiber, Douglas R. Curtis
  • Patent number: 5341089
    Abstract: A multimeter converts an input voltage into decibels. Preferably, the input voltage is converted into dbm. The multimeter includes a table of voltage values wherein each entry is associated with a given decibel value. The input voltage is compared with entries in the table to locate a first entry which is larger than the input voltage. A second entry having a lower value than the input voltage is then located in the table. A fractional value that is indicative of where the input voltage lies at a range between the first entry and the second entry is calculated using the first and second entries. The fractional value is added to a decibel value corresponding the second entry to produce a decibel value for the input voltage. The input voltage may be scaled down into an appropriate operational voltage range and then the calculated decibel value may be scaled up to compensate for this scaling down.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: August 23, 1994
    Assignee: Tandy Corporation
    Inventor: Jerry J. Heep
  • Patent number: 5321563
    Abstract: A circuit for generating a bias signal and an erase signal for use in a recording apparatus having a record head for recording an input analog signal on a magnetic tape, and an erase head for erasing information from the tape. A DC erase signal is applied to the erase head in response to the erase control signal to cause the erase head to erase information. An AC bias signal is generated and is combined with the input analog signal to make a record signal. The record signal is applied to the record head in response to the record control signal to record information on the tape. A controller generates an erase control signal and as record control signal. The AC bias signal is generated by an AC bias oscillator, such as a Hartley oscillator to reduce the noise contributed in the recording system. Use of a DC source to drive the erase head reduces the cost of the circuit, while maintaining a significant increase in the signal-to-noise ratio.
    Type: Grant
    Filed: June 15, 1992
    Date of Patent: June 14, 1994
    Assignee: Tandy Corporation
    Inventors: Robert Sanford, Robert Cook, Gerald Stuteville
  • Patent number: 5310997
    Abstract: A system for processing merchandise sale transactions for customers in a point of sale and warehouse facility. A main processor has a database for storing customer identification information and merchandise information and processes sale transaction records for customers. A point of sale system coupled to the processor has a controller and at least one pen-based computer in communication with the controller via RF transmissions. Program instructions respond to entry on the computer of a customer number and to entry of merchandise identification numbers to build a sale transaction record of selected items for purchase. The program instructions display item information and enable selection of items for addition to the sale transaction record, display delivery method instructions and enable their selection for addition to the sale transaction record, and transmit the transaction record to the processor to effectuate warehouse delivery of the selected items according to the selected delivery instructions.
    Type: Grant
    Filed: September 10, 1992
    Date of Patent: May 10, 1994
    Assignee: Tandy Corporation
    Inventors: John V. Roach, Richard Hollander
  • Patent number: 5294889
    Abstract: A capacitance measuring circuit uses only a DC voltage source to perform the capacitance measurement. For this purpose, the circuit is arranged to charge an unknown capacitor which is being measured from a DC source and to discharge the capacitor through a constant current circuit such that the discharge voltage across the capacitor decreases linearly from its initial value to a predetermined, final value. The measurement circuit monitors the time taken by the capacitor to discharge in order to determine the capacitance value.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: March 15, 1994
    Assignee: Tandy Corporation
    Inventors: Jerry J. Heep, Douglas R. Curtis
  • Patent number: 5263101
    Abstract: An optical scanner filter screen for use with an optical scanner, and method for use, comprising a colored optical filter or optical glass placed between the scanning mechanism of the optical scanner and the document to be scanned, for improving the accuracy of the reproduction of the document resulting from the optical scan by increasing contrast and reducing reflection and distortion of the light read by the scanning mechanism.
    Type: Grant
    Filed: July 9, 1990
    Date of Patent: November 16, 1993
    Assignee: Tandy Corporation
    Inventor: Barbara M. Barbolla
  • Patent number: 5261072
    Abstract: Method and apparatus for continuously reading data from a compact disk drive to a host computer is disclosed in which the data is transferred to the computer's cache memory so that it is available to the computer's central processor for processing without interruption. A communication link is established between a processor in the disk drive and a direct memory access (DMA) controller in the host computer. With this link established, the DMA controller directs the transfer of the incoming data stream from the drive to the cache memory of the host computer. Once the data is in the cache memory, it is moved to the application workspace of the computer's system random access memory (RAM) for processing by the central processor. The transfer of data by the DMA controller, and the temporary storage of the transferred data in the cache memory, allows for continuous transfer of data from the compact disk drive, without interruption, and without the need for reseeks of the data.
    Type: Grant
    Filed: October 31, 1991
    Date of Patent: November 9, 1993
    Assignee: Tandy Corporation
    Inventor: Mark D. Siegel
  • Patent number: 5258826
    Abstract: A palette for converting video data encoded in multiple YUV and RGB formats into a configuration suitable for transmission to a display and a multimedia system incorporating the same.
    Type: Grant
    Filed: August 18, 1992
    Date of Patent: November 2, 1993
    Assignee: Tandy Corporation
    Inventors: Carl K. Wakeland, Dale Chatham
  • Patent number: 5254984
    Abstract: A VGA controller having an overlay mode for displaying images formed from selective components of multiple image planes. A first image and a second image overlaying the first image are interleaved into three of four bit planes of a dynamic random access memory. When displaying the image, the controller will simultaneously read from the first and second images. If the value of the second image is non-zero, then the second image is displayed. Otherwise, the first image is displayed.
    Type: Grant
    Filed: January 3, 1992
    Date of Patent: October 19, 1993
    Assignee: Tandy Corporation
    Inventor: Carl K. Wakeland
  • Patent number: 5231624
    Abstract: A system and method for recording on optical storage media utilize a beam projection assembly including a collimating lens and an objective lens. By providing an incident light beam having a substantially constant energy distribution to the objective lens, the radius of the spot projected on the optical media having an intensity greater than a threshold intensity may be increased. The radius may be further decreased by modifying the optics of the objective lens, typically by providing a center stop plate on the lens or by providing a one-half wavelength plate on the lens.
    Type: Grant
    Filed: August 1, 1991
    Date of Patent: July 27, 1993
    Assignee: Tandy Corporation
    Inventor: Joel D. Finegan
  • Patent number: 5219130
    Abstract: A reel-locking device for a video cassette. One or more stationary teeth are positioned to engage corresponding teeth on the perimeter of the video cassette tape reel. When the video cassette is inserted into a recorder, the recorder causes the reel to be raised above the effective height of the stationary tooth to disengage the reel from the tooth and permit rotation thereof.
    Type: Grant
    Filed: June 12, 1992
    Date of Patent: June 15, 1993
    Assignee: Tandy Corporation
    Inventor: Ernest D. Boshek
  • Patent number: 5220410
    Abstract: Method and apparatus within a multimedia system for digitally decoding video pixel data. The pixel data is decoded to 24 bits per pixel from a compressed 8 bits per pixel format. The compressed pixel data is deformatted into its separate luminance and chrominance components. The components are then differentially expanded and assigned to associated pixel elements. Predominant color transitions are designated to determine the pixel location where the chrominance components change. An interpolated chrominance component may be inserted at these color change locations to smooth out the color transitions.
    Type: Grant
    Filed: October 2, 1991
    Date of Patent: June 15, 1993
    Assignee: Tandy Corporation
    Inventors: Carl K. Wakeland, Dale Chatham
  • Patent number: 5218432
    Abstract: A method for merging first and second digital video signals generated by first and second video controllers, respectively, for merged transmission to a digital video decoder. The first video controller transmits the first digital video signal to the decoder while monitoring the signal to detect a luminance component which designates the boundary between a first image constructable from the first video signal and a second image constructable from the second video signal. When the luminance component is detected, a colorkey signal is generated by the first video controller and transmitted to the second video controller to initiate transmission of the second digital video signal to the decoder in place of the first digital video signal. The first video controller continues to monitor the first video signal until the absence of the luminance component is detected.
    Type: Grant
    Filed: January 2, 1992
    Date of Patent: June 8, 1993
    Assignee: Tandy Corporation
    Inventor: Carl K. Wakeland
  • Patent number: 5216658
    Abstract: An apparatus and method for erasing data from optical media in dual beam systems. The erase spot is focused to have a diameter equal to three times the track pitch of the medium. The larger erase spot eases spot alignment requirements since even beam misalignments of half a track width still supply enough energy to the medium to erase the data bump. The larger erase spot heats a larger area more gradually than a single track width erase beam and thereby also enables a more complete erasure of the medium.
    Type: Grant
    Filed: July 26, 1990
    Date of Patent: June 1, 1993
    Assignee: Tandy Corporation
    Inventor: Bryan Clark
  • Patent number: 5207596
    Abstract: An improved coaxial cable connector and method for attaching the same to a coaxial cable is disclosed. The improved cable connector comprises a center conductor pin, which may be hollow or solid, for providing electrical conductivity for the center wire, an outer conductor shell, which is concentric to the center pin, for providing electrical conductivity for the shielding wire, and an annular dielectric, such as a phenolic washer, mounted to the center conductor pin for insulating the conductor pin from the outer conductor shell. The improvement lies in the use of an inner wire receptor having a funnel portion for receiving the center wire and a holding portion, which is crimped, for mechanically and electrically securing the center wire.
    Type: Grant
    Filed: March 19, 1992
    Date of Patent: May 4, 1993
    Assignee: Tandy Corporation
    Inventor: Nam D. Tran
  • Patent number: 5208801
    Abstract: An optical recording system. The system is directed towards optical recording media which is responsive to at least two wavelengths of light such as an erase beam and a record beam. Light of a lower wavelength is produced by a divergent light source such as a diode and only partially collimated in a collimating lens. When the record and erase beams pass through a common objective for focusing on the recording media, the slightly divergent lower wavelength beam is focused at the same location as the fully collimated higher wavelength beam.
    Type: Grant
    Filed: August 23, 1991
    Date of Patent: May 4, 1993
    Assignee: Tandy Corporation
    Inventor: Joel D. Finegan
  • Patent number: 5206767
    Abstract: A method and apparatus for editing video cassettes. The video cassette editor can be used to move a video cassette to a particular position on the tape relative to a reference point as a function of tape length expressed in units of time. The video tape editor is also capable of calculating recording speed switchover points for maximizing the recording time in standard play mode and thereby increasing the quality of the video image for the maximum amount of time.
    Type: Grant
    Filed: December 29, 1989
    Date of Patent: April 27, 1993
    Assignee: Tandy Corporation
    Inventor: Jerry J. Heep
  • Patent number: 5200948
    Abstract: An optical storage medium is disclosed. In general, the storage medium includes a substrate, with a first, expansion layer, a second, reflective layer bonded to the first layer, and a third, retention layer bonded to the second layer, opposite the first layer. An opto-electronic system for recording data is also disclosed, along with a method of manufacture of the storage medium.
    Type: Grant
    Filed: January 10, 1989
    Date of Patent: April 6, 1993
    Assignee: Tandy Corporation
    Inventors: Paul R. Goldberg, Bryan K. Clark, Joel D. Finegan, Robert Guerra
  • Patent number: 5194978
    Abstract: A remote controller capable of learning and later transmitting infrared signals transmitted by any other remote controller. The remote controller determines which of four modes of transmission a signal is transmitted in, including carrier mode, pulse mode, frequency shift keying mode and continuous wave mode. Once the type of signal is determined the controller learns each signal, saves them and later replays them to control a remote device.
    Type: Grant
    Filed: November 18, 1991
    Date of Patent: March 16, 1993
    Assignee: Tandy Corporation
    Inventor: Jerry J. Heep
  • Patent number: 5189660
    Abstract: A moving coil, linear positioning transducer actuator suitable for optical recording and playback devices is constructed by forming the actuator frame, magnetic pole pieces and the magnetic core of the moving coil from a single piece of ferrous material and wherein the path of the moving coil and transducer are substantially collinear. The transducer is supported by parallel rails which are mounted to the frame.
    Type: Grant
    Filed: May 9, 1991
    Date of Patent: February 23, 1993
    Assignee: Tandy Corporation
    Inventor: Marcus L. Caldwell