Zenith Electronics Corporation

Zenith Radio Corporation

Frank C Templin

Thomas J Zato

Peter C Skerlos

Paul A Snopko

Dong Hyun Lee

Ronald B Lee

In Sun Lee

Raymond C Hauge

Moon Key Lee

Jong Guk Kim

David L Blanchard

A circuit for developing correction signals for on-line controlling a precorrection arrangement in an HDTV 8VSB digital signal transmitter. The transmitted signal is sampled, sorted, smoothed and sliced to determine the symbol amplitude levels of the transmitted multilevel symbols. The centers of the sliced clusters of sampled symbol levels are used to determine the symbol amplitude levels. Correction signals for compensating the precorrection arrangement are developed based upon the determined symbol levels and the known symbol levels.

Non linear amplitude precorrection for HDTV transmitter

A high definition television transmitting system includes a source of high definition analog RGB video signals which are converted to corresponding digitally encoded signals and thereafter compressed by a video encoder to a six megahertz bandwidth. The compressed data is formatted by a transmitter and processed in accordance with a Reed-Solomon error control system for broadcast as an NTSC-type broadcast signal. A high definition television receiver includes a high definition signal receiver coupled to the transmitter by a transmission link. The receiver extracts the compressed video, audio and ancillary data signals and applies a Reed-Solomon error correction thereto. The compressed video data is reconstructed by a video decoder and processed for high definition display. A high definition digital video tape recorder is coupled to the transmitter by an interface and format converter facilitating both recording and playback functions of the digital video tape recorder while maintaining the Reed-Solomon error control. The format converter provides compatibility between the high definition transmitter and the digital video tape recorder.

High definition television signal format converter

A microcomputer-controlled televison receiver tuning system requires only a limited memory capacity for the storage of a limited number of preferred channels. Memory size and microcomputer programming complexity are minimized by means of a stack memory which is programmed by keyboard entry of each of the preferred channel numbers followed by selection of an ENTER key after each entry. The preferred channel numbers may thus be sequentially loaded into the stack memory in any order and accessed in increasing and decreasing numerical order by selection of channel scan tuning keys, i.e., either tuning up or tuning down through the stack. If the ENTER key is not selected, the television receiver tunes to the selected channel number which is not loaded into the stack memory. In one embodiment, only the last six channels selected with the digit and ENTER keys are stored in the stack in a first-in/first-out order. Regardless of the order in which the preferred channel numbers are stored in memory, increasing or decreasing channels are accessed sequentially upon selection of either the channel up or channel down key.

Stack memory tuning

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 system for controlling a channel/band selective microcomputer programmed indirect frequency synthesis tuner is disclosed. Separate groups of VHF, UHF or CATV channels are programmed by means of a key switch having various positions of engagement corresponding to individual groups of channels. Following key switch selection of a given group of channels, any number of channels within that group may be programmed for viewing by means of channel UP and DOWN selector keys. A RAM is used to store 'saved' and 'skipped' channels for each key switch position. A backup non-volatile MNOS memory is provided for preserving stored data in the event AC power is removed. Also provided is programmable raster blanking for audio-only channels thus eliminating unwanted video snow. Front panel LED indicators inform the programmer of the status of each channel during television receiver programming. The television receiver is turned on by viewer selection of either the channel UP or DOWN control resulting in tuning to either the lowest or highest 'saved' channel. The OFF function is activated anytime an attempt is made to advance past either the highest or lowest programmed channel by providing either a channel UP or DOWN command, respectively. Thus, television receiver control is by means of a single user selector. A wired remote controller with a speaker is also provided.

Selective video reception control 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.

Growing community of inventors

Arlington Heights, IL, United States of America

Frank C Templin