Zenith Radio Corporation

Zenith Electronics Corporation

Peter C Skerlos

Thomas J Zato

Peter Strammello, Jr

Frank C Templin

Gopal K Srivastava

Paul A Snopko

Carl Campisi

Gary A Jones

David C Kilinskis

Egil Sorlie

Richard A Smirl

Jeffery A Puskas

A digital video communication system includes a two-way communication link between a source and a viewer. A video program, in sequential compressed digital form, is repetitively supplied to a fifo memory that has taps corresponding to the number of fixed length segments in the video program. The program is taken from one of the taps and supplied to a one segment-long fifo memory which has taps corresponding to fields in the segment. A program request by a viewer results in the segment at which the beginning of the program will next appear to be addressed and remembered. The field fifo is reset to the first tap and the video program data is processed and transmitted to the viewer from the first field tap. Should the viewer wish to interrupt the video program, a field counter is enabled by an interrupt signal to step over the field taps (at the field rate), thus 'freezing' the program. The interrupt signal also causes the address counter to count up (change tap addresses) at the segment rate. When the interruption request is removed, the normal program transmission is restored from the 'frozen' field of the video program.

Method of accessing a repetitively transmitted video program

A microprocessor based TV/TTX processor includes a stored pages ROM in the TTX processor for storing on-screen display messages and lists of functions and characteristics as pages of TTX data. An RGB switch is coupled to receive the output of a character generator in the TTX processor and to receive the video output of the TV for selectively displaying information from each source with or without the on-screen messages and lists. The stored pages ROM relieves the microprocessor of the necessity of generating the on-screen messages and lists. Items on the list are controllable by the viewer and an indication of the status of the item is given by the microprocessor changing a character in the display memory of the TTX processor.

Television receiver having teletext processor with ROM for on-screen

An electronic component matching system operates in conjunction with a component transport arrangement wherein a component-carrying supply tape from which components are removed for positioning upon a circuit board in a matched manner is linearly displaced. The components are thus sequentially moved to a pick-up point whereupon a predetermined number N of components having similar operating characteristics are incorporated in the same circuit. As the component-carrying supply tape is displaced toward the component pick-up point, an electro-optical sensor detects the presence or absence of components on the supply tape and provides this information to a microcomputer controller. The stationary sensor is positioned in spaced relation from the pick-up point along the component-carrying supply tape displacement path to allow for the detection of the predetermined number of components between the sensor and the pick-up point to ensure that a matched set of N components is available on the tape for incorporation in the same circuit. If the sensor determines that less than N components are present between the sensor and the pick-up point, the microcomputer advances the supply tape to the next group of matched components to prevent components from different matched groups having different operating characteristics from being incorporated in the same circuit. This system is particularly adapted for the automatic positioning of components such as transistors and diodes having matched operating characteristics for incorporation in the same circuit.

Method and apparatus for electronic component matching

An all-channel television tuner includes a single 75 ohm input for receiving airborne signals and CATV signals. A single band high frequency section tunes frequencies from 370 to 806 MHz and a three band low frequency section tunes frequencies from 54 MHz through 370 MHz. Both sections are coupled to the 75 ohm input through signal diverting means. A channel selector provides tuning voltages and band switching voltages to the sections and to the signal diverting means as a function of the channel selected.

All-channel television tuning system

A tuning system employing a UHF tuner for tuning a television receiver over the UHF band and the ultraband is disclosed. The system employs indirect frequency synthesis in providing user initiated, microcomputer generated commands to the tuner in the form of a channel number and an operating mode control word. Inter-channel spacing of 6 MHz is maintained over both tuning bands with a respective channel in one band offset from the closest channel in the other band by 2 MHz.

Dual mode UHF tuning system

A system for remotely controlling several devices in which both the indicia identifying the controlled device as well as the function indicia are generated by means of the selection of a single input control. A keyboard is bi-directionally scanned in detecting the user-selected input control signal. The control signal is then decoded to provide an indication of the function input signal as well as an indication of the particular device being addressed. The thus decoded signals are then used to generate a predetermined output pulse code for remotely controlling one of a plurality of functions in one of the plurality of controlled devices. The output pulse code includes a start bit (or bits) and various numbers and combinations of data bits depending upon the device addressed. The indicia identifying the controlled device are generated either by hard-wiring an address decoder to the user-operated input signal generator, i.e., a keyboard, or by storing address information in a programmable memory and recalling this information in response to the control input selected. The various devices controlled are responsive to unique start bit and data bit combinations in the form of ternary digital signals having three possible states which provide an increased number of available codes. The use of a single input control for generating device addresses as well as control function information eliminates the need for multiple control signal entries, a mode switch for selecting a particular device or for sequentially transmitting address and function control signals.

Multi-function, multi-unit remote control system and method therefor

A remotely located and controlled programming controller for a cable-compatible television receiver is disclosed. Cable head end-generated control signals are provided by wire to the cable TV controller for selectively enabling the reception of subscribed-to CATV channels by the television receiver. Coded subscriber addressing and operating mode control signals are provided to each controller in the cable network for selectively enabling/disabling each controller for limiting cable programming distribution. Each controller is responsive to transmitted operating mode control data bits for enabling/disabling individual cable channel reception. In addition, each controller is assigned and responsive to subsequently transmitted, uniquely coded address identifier data bits. Operating mode control and address data are represented respectively by the first and last bit groups of the head end-generated cable access signal. The programming controller may be remotely located in coupling the television receiver to the cable network with system status monitoring provided by head end-generated probe signals for enhanced programming security.

CATV Service controller

A television receiver incorporating telephone interface circuitry permitting the viewer to remotely place outgoing calls by recalling a selected number from memory is disclosed. An infrared link is used for remotely answering incoming calls, initiating outgoing calls and programming a nonvolatile memory with a plurality of preferred telephone numbers for future use. The nonvolatile memory circuit is accessed by means of a microcomputer in response to user-initiated, remotely generated commands. The television receiver's display performs a user interactive function in displaying television/telephone mode operation information, the contents of user-accessed locations in the nonvolatile memory and the telephone number being stored in memory during the programming mode of operation. The microcomputer controls not only the telephone mode of operation of the system, but also television operation in generating digital tune words in response to a channel number entry and providing these tune words to an indirect frequency synthesis type of television receiver tuner. The contents of the nonvolatile memory may be updated, or changed, as desired by user selection of appropriate controls followed by entry of the new telephone number which is presented on the video display as it is entered for user verification. The video display is then cleared upon return to the television mode of operation or upon television receiver turn-off.

Television/telephone system with automatic dialing

A pulse code modulated (PCM) infrared (IR) remote control detector/decoder with improved noise immunity particularly adapted for use with a television receiver is disclosed. The IR pulses are modulated by means of a high frequency clock signal in translating the transmitted signal to a higher frequency, more noise immune portion of the IR spectrum. After receipt of the transmitted signal by a signal detector, the high frequency modulation is removed from the pulses which are then decoded. Under the control of a microcomputer, the decoder looks for the start data bit and, if received, the subsequent control instructions. When the data transmission has been decoded, the microcomputer activates the appropriate control outputs to the television receiver's tuner system to achieve the desired control function.

IR Remote control detector/decoder

An extended range tunable resonant circuit for use in a VHF television receiver tuning system comprises a bandswitchable inductive network connected to a low series resistance gallium arsenide varactor diode. The resonant circuit, when operated in response to appropriate bandswitching signals and tuning voltages, is effective for establishing a plurality of tuning bands collectively defining an extended sub-UHF tuning range from about 54 MHz to at least 408 MHz.

Extended range tunable resonant circuit for a VHF television receiver

A character generator driven by a microcomputer and providing latched outputs is disclosed. Flexibility in character size and character array positioning on the video display is provided for in this 60-character display generator integrated circuit. A plurality of latched outputs permits the character generator to perform additional functions while reducing the number of dedicated microcomputer outputs required to perform these and similar functions. The character generator is particularly adapted for use in a television receiver where characters are displayed on the face of the cathode ray tube.

Character generator with latched outputs

A television/telephone loudspeaker system is disclosed wherein feedback oscillation caused by having a speaker phone system simultaneously in the transmit and receive mode is minimized. Improved separation of transmit and receive signals is accomplished by microprocessor-controlled dynamic balancing of a bridge network coupled to a telephone isolation transformer to which the incoming and outgoing calls are provided. In addition, by microprocessor sampling of the television receiver's loudspeaker drive voltage from the telephone input line, dynamic proportional attenuation of microphone gain (AGC) is digitally accomplished in simulating full duplex operation. Bridge balancing is accomplished by means of test signals output by the microprocessor during quiet periods with various other audio signal refinements, such as room background noise cancellation, available with the constant monitoring of the microphone signal. Audio and visual indications of an incoming telephone call are provided by the television receiver's tuning system microcomputer which detects and decodes user remote commands and activates a phone relay and phone light emitting diode (LED) drivers.

Pseudo-full duplex television/telephone loudspeaker system

A television receiver incorporating telephone interface circuitry permitting the viewer to not only answer incoming calls but also place outgoing calls by means of the television receiver is disclosed. An infrared link is used for remote control telephone answering and dial-out with a tuner-integrated microcomputer used to drive a character generator permitting the number dialed to be displayed on the television receiver's video display and to be provided to a standard telephone line. An automatic re-dial feature is provided by means of the microcomputer's memory whereby the last phone number dialed by the remote transmitter may be stored in memory, recalled by means of a single button selection, presented on the on-screen display and automatically dialed. The microcomputer-driven character generator also controls telephone interface circuitry and switching between television and telephone modes while providing for a privacy mode in which a television-mounted microphone is turned off in selectively muting audio output to the other telephone subscriber.

Microcomputer-controlled television/telephone system and method therefore

An all-electronic, integrated television channel tuning indirect frequency synthesis system capable of operating over the VHF, UHF and CATV spectra in which digital bandswitching is accomplished automatically. Keyboard selected control inputs are provided to a microcomputer for the generation of digital bandswitching signals and, in combination with a phase locked loop, tuning voltages. The bandswitch signals and tuning voltages are provided to a tuner having several resonant frequency circuits, each including a varactor diode and a plurality of coupled inductors and switching diodes.

Multi-mode automatic channel frequency synthesis system

An electronic, microcomputer-controlled television tuning system capable of acquiring channels offset by as much as 3.25 MHz from the designated frequency while also being able to accurately tune in channels operating at the designated frequency. After synthesizing the correct channel frequency, the microcomputer looks at AFC discriminator information from which local oscillator tuning voltage direction is determined. To achieve automatic fine tuning the tuning voltage is then stepped by the microcomputer in small frequency increments which vary from 28 KHz for channel 2 to 90 KHz for channel W in the direction of the desired frequency until the center video carrier frequency is passed. The tuning voltage is then returned to the preceding step to which frequency the receiver is then locked. With essentially all broadcasting stations operating at, or very close to, the FCC-designated frequency, highly accurate tuning to the selected channel is thus permitted. Video carrier verification is accomplished by microcomputer analysis of AFC discriminator and vertical sync states.

Growing community of inventors

Arlington Heights, IL, United States of America

Peter C Skerlos