Including Compensation For Transmission Delays Patents (Class 348/518)
  • Publication number: 20010017671
    Abstract: Improvements in systems and methods for replacement of a target region in successive video images transmitted via a digital data stream. In one aspect, the invention provides for replacing only those portions of the target region that are not overlaid with added graphics, such as text. In another aspect, the invention provides for personalizing the video images by selecting the object to replace the target region based on information regarding the viewer or user.
    Type: Application
    Filed: March 8, 2001
    Publication date: August 30, 2001
    Inventors: Pierre Pleven, Pierre Bruno, Jean-Jacques Grimaud
  • Patent number: 6275265
    Abstract: An apparatus for performing a generator locking for a video signal including a first video processing circuit for processing an input video signal, an expansion module having a second video processing circuit and a delay circuit having a delay time introduced by said second video processing circuit, a synchronizing signal separating circuit for separating a synchronizing signal from an external reference signal, and a phase-lock loop circuit for generating a reference control signal for said first video processing circuit as well as a phase comparison signal. Said phase comparison signal is fed-back to the phase-lock loop circuit by means of said delay circuit. Although the expansion module is connected to the expansion slot, a phase of a finally obtained video signal is remained in a same fixed relationship as a phase relationship when a connection board is connected to the expansion slot.
    Type: Grant
    Filed: June 19, 1998
    Date of Patent: August 14, 2001
    Assignee: Ikegami Tsushinki Co., Ltd.
    Inventors: Hiromitsu Kimura, Shinichi Takahashi
  • Patent number: 6262695
    Abstract: A method and apparatus for phase-locking a plurality of display devices and multi-level driver for use therewith. Each of the display devices displays an image under the control of a distinct clock having a distinct clock rate. Each of the images contains a predetermined periodic indexing event. One of the clocks is designated as a master clock. The times of occurrence of the indexing events are compared, and the times of occurrence are caused to fall within a predetermined amount of time of one another so that each of the other clocks is phase-locked with the master clock.
    Type: Grant
    Filed: November 16, 1998
    Date of Patent: July 17, 2001
    Assignee: Tridium Research, Inc.
    Inventor: Scott J. McGowan
  • Patent number: 6246439
    Abstract: A method and apparatus for transparently embedding data into a video signal modulates a particular carrier frequency with a randomized pattern representing the data. The randomized pattern may be a combination of the data with the output from a pseudo-random binary sequence generator, or the data may be converted first into a bi-orthogonal pattern selected from among a plurality of such patterns and then randomized. The resulting modulated carrier frequency is then amplitude modulated based upon a human visual model so that the modulated carrier frequency amplitude is greater in areas of high image complexity and lower in areas of low image complexity. The subliminal data represented by the modulated carrier frequency is added to the video signal.
    Type: Grant
    Filed: March 17, 2000
    Date of Patent: June 12, 2001
    Assignee: Tektronix, Inc.
    Inventors: Scott E. Zink, Daniel G. Baker
  • Patent number: 6243032
    Abstract: An A/V signal pickup unit receives an audio digital data stream. A CPU carries out a decode process, and adds tag data indicating the attribute of audio sample data to provide the same to an audio signal converter unit. The audio signal converter unit controls the timing of the output operation of sample data according to the tag data.
    Type: Grant
    Filed: September 20, 1999
    Date of Patent: June 5, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shinichi Uramoto, Tetsuya Hara
  • Patent number: 6191821
    Abstract: A method and apparatus for synchronizing unrelated reference signals originating from two or more sources at different locations, which signals may be in different signal formats and/or subject to different delays at the receiving station. A master generator having an absolute time input from a highly stable time source generates a master reference signal having a frequency that is a common multiple of the frequencies of the unrelated reference signals. A counter is implemented from an arbitrary initial time point and the time elapsed from the initial time point to a synchronizing event is periodically encoded into the master reference signal as time code data. A slave generator associated with each information signal is genlocked to the master reference signal, and the time code data is encoded into the slave reference outputs.
    Type: Grant
    Filed: May 29, 1998
    Date of Patent: February 20, 2001
    Assignee: Leitch Technology Corporation
    Inventor: Richard A. Kupnicki
  • Patent number: 6175604
    Abstract: A technique has been devised which may be used to synchronize a receiver clock to a transmitter clock at either end of a transmission network having jitter intrinsic therein. The technique is characterized by a modified least squares linear regressive approach which takes advantage of assumptions particular to such transmission networks. The technique finds advantages in comparison to commonly used phase-locked loop techniques which have long startup phase delays where clocks are not in sync. The modified least squares linear regressive technique of the invention provides excellent isolation of jitter and other timing variations while simultaneously providing for quick startup.
    Type: Grant
    Filed: July 27, 1998
    Date of Patent: January 16, 2001
    Inventors: Raffaele Noro, Jean-Pierre Hubaux, Maher Hamdi
  • Patent number: 6160548
    Abstract: A method and system for synchronizing modules associated with audiovisual devices, generally for use with a digital non-linear editor. A logical clock communicates information, including time and state (clock operating mode) information, to hardware and software modules through a synchronization port. The synchronization ports convert the time information into values recognizable by the module, and offset the time as needed to maintain synchronization. The state information may effect module commands for controlling audiovisual devices, such as rewind, playback and capture commands to tape players, timed such that various devices having different preparatory timing requirements are synchronized. State information, such as information indicating that a device is ready, may be returned by the modules. Video editing features such as scrubbing, looping and frame-stepping are supported by the mode information that is communicated between the clock and the synchronization ports.
    Type: Grant
    Filed: April 15, 1997
    Date of Patent: December 12, 2000
    Inventors: Christopher B. Lea, Raymond Hill, Adam D. Barr
  • Patent number: 6151071
    Abstract: A method and apparatus of correlated double sampling is disclosed by creating sampled and clamped signals from CCD imager outputs that are in phase with the CCD imager outputs comprising: providing an image sensor having an analog output; sensing the output of the image sensor via system electronics; identifying and extracting portions of a reset signal within the analog output signal; and modifying existing clocks in response to extracted portions of the reset signal.
    Type: Grant
    Filed: February 29, 1996
    Date of Patent: November 21, 2000
    Assignee: Eastman Kodak Company
    Inventor: Eugene M. Petilli
  • Patent number: 6088063
    Abstract: There occurs an output timing lag between audio and video, for example, in case of building a system. Excessive frame skipping, etc. occurs. Prior to comparing a PTS and an SCR of MPEG within an apparatus, an offset value is added to the value of PTS. A minus offset value is used for a fast decode process. Offset values are written into an audio offset value register etc. by a host CPU. A value obtained by adding PTS and an offset value and an internal clock SSC depending on an SCR are compared by an adder-subtracter. If comparison shows the decode process is still fast, a decision controller instructs, for example, display of the same frame twice.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: July 11, 2000
    Assignee: Rohm Co., Ltd.
    Inventor: Kosuke Shiba
  • Patent number: 6072832
    Abstract: In an audio/video/computer graphics data synchronous reproducing/synthesizing system, a demultiplexer separates a bit stream in which an audio signal, a video signal, and computer graphics data are compressed and multiplexed, into compressed audio and video signal streams, audio and video signal time reference values, and a compressed computer graphics data stream. An audio PLL generates a first decoding clock. An audio decoder decodes the audio signal. An audio memory stores the decoded audio signal. A modulator modulates the audio signal in accordance with sound source control information. A video PLL generates a second decoding clock. A video decoder decodes the video signal. A video memory stores the decoded video signal. A CG decoder decodes the computer graphics data and event time management information. A CG memory stores the decoded computer graphics data. An event generator generates an event driving instruction. A detector detects viewpoint movement of an observer.
    Type: Grant
    Filed: October 24, 1997
    Date of Patent: June 6, 2000
    Assignee: NEC Corporation
    Inventor: Jiro Katto
  • Patent number: 6005633
    Abstract: A signal transmitting-receiving system which has a signal transmitting side system constructed by signal transmitter T1, voice processor T2 and signal receiver T3 and also has a signal receiving side system constructed by signal receiver R1, synthesis circuit R4, signal transmitter R5 and delay circuit R3. The signal transmitting-receiving system is constructed such that no processing for making a video signal coincide with a voice used in communication using voices in position on a time axis is performed.
    Type: Grant
    Filed: March 18, 1997
    Date of Patent: December 21, 1999
    Assignee: Sony Corporation
    Inventor: Hiroshi Kosugi
  • Patent number: 5990967
    Abstract: The transmitting device latches the time of the absolute clock when the V-sync signal of the video signal block is transmitted, adds to the latched time a predetermined delay time equivalent to the sum of the time required for the transmitting device to process the video signal block and the time required for the transmittance; and transmits the resulting sum value together with the video signal block. The receiver extracts the sum value and produces the V-sync signal delayed by said predetermined delay time.
    Type: Grant
    Filed: January 3, 1996
    Date of Patent: November 23, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasunori Kawakami, Hiroyuki Iitsuka, Hidetoshi Takeda
  • Patent number: 5959703
    Abstract: In an error data removing apparatus and method by decoding delay in a DTV system which employs a decoder of the VSB standard, respective segments or respective fields are divided into area 1 and area 2 using a starting point of decoded data as a reference to provide the decoded data of said area 1 section without involving delay and provide the decoded data of said area 2 section by delaying as long as a sync signal. A memory is utilized as the decoded data delay apparatus, and at this time, a value of a counter used for generating an address for reading/writing of the memory is utilized to delay the segment sync signal and field sync signal as required without separately using flip-flop or memory.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: September 28, 1999
    Assignee: Hyundai Electronics Ind Co., Ltd.
    Inventors: Dae-Il Oh, Eung-Ryeol Kim, Dae-Hyun Kim, Won-Jin Lee
  • Patent number: 5923364
    Abstract: A video security system (10) capable of monitoring and recording fixed and moving targets and recording management information into a video signal such that the text can be removed from the video image produced by the video signal at playback of the recorded video signal. The VSS (10) allows a camera (70b) to switch (toggle) between two or more view positions of interest and to set the view positions into memory by pressing a single switch. The cameras (70b) are controlled to move rapidly, but accurately, between the positions within controlled parameters of speed and acceleration--including a period of substantially zero acceleration between changes in the rate of acceleration.
    Type: Grant
    Filed: April 17, 1998
    Date of Patent: July 13, 1999
    Assignee: Maxpro Systems Pty Ltd
    Inventors: Scott Anthony Rhodes, Andrew William Jackson
  • Patent number: 5847769
    Abstract: A delay tracker utilizes a special code on the tracked signal in order to recognize such signal and ascertain any delays associated therewith.
    Type: Grant
    Filed: March 21, 1996
    Date of Patent: December 8, 1998
    Inventor: James Carl Cooper
  • Patent number: 5835165
    Abstract: A concatenated three layer Viterbi, Reed-Solomon/Deinterleaver and Descrambler forward error correction decoder may be utilized in digital video and audio systems, and for direct broadcast satellite applications. The digital signal may be a compressed video and audio signal transmitted from a direct broadcast satellite. Acquisition for three layers of synchronization are required, but once all three layers are in-sync, down stream data synchronization monitoring will suffice so that upstream synchronization monitoring can be disabled thus improving system robustness to noise bursts and false synchronization on false sync bytes generated at the transmission encoder during non-changing data signal conditions.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 10, 1998
    Assignee: LSI Logic Corporation
    Inventors: Christopher Keate, Nadav Ben-Efraim
  • Patent number: 5798804
    Abstract: In an image decoder of MPEG system or the like, a delay buffer which is able to store data which corresponds to at least one frame is provided in the rear stage of an input buffer which is normally provided, and a frame synchronizing pulse is applied to determine the timing of display independently of that which is determined by the bit stream. In synchronization with the frame synchronizing pulse which occurs for the first time after the passage of a delay period set for every frame in each of the bit streams, that frame is displayed. The input bit streams coming in during the period of time which elapses from the passage of the delay period until the occurrence of the frame synchronizing pulse, are absorbed by the delay buffer.
    Type: Grant
    Filed: February 5, 1996
    Date of Patent: August 25, 1998
    Assignee: Yamaha Corporation
    Inventor: Hiromi Okitsu
  • Patent number: 5774466
    Abstract: A regulation apparatus for ATM cell delay variation includes a variation regulating buffer for temporarily storing cells transferred thereto, a variation waiting timer for controlling a waiting time which extends from reception of the first cell to read-out of cells from the buffer, a read-out timer for controlling intervals at which cells are read from the buffer, a latest cell preservation memory for storing the latest cell transferred from a VPI/VCI demultiplexing unit and, a selector for selecting a cell stored in the buffer or in the memory to transfer the selected cell to a cell reproduction unit.
    Type: Grant
    Filed: November 17, 1995
    Date of Patent: June 30, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Shinichi Hamamoto, Masashi Hiraiwa, Atsuo Hatono
  • Patent number: 5764298
    Abstract: A transcoder converts a received data stream encoded according to a first coding scheme to a data stream coded according to a second coding schem. The schemes specify a first and a a second maximum amount of jitter that may be present in the encoded data streams, respectively. The transcoder includes a decoder section and an encoder section and is operated such that the data stream received by the encoder section has a non-zero amount of jitter and the encoder section produces a coded data stream having an amount of jitter which is less than or equal to the second maximum amount of jitter. By operating the transcoder to provide a decoded video data stream to the encoder section which retains a degree of jitter relative to the oriignal video signal, the buffer requirements can be minimized therefore providing reduced buffeer delay and hence a transcoder with smaller buffer delay than previously obtainable.
    Type: Grant
    Filed: September 14, 1995
    Date of Patent: June 9, 1998
    Assignee: British Telecommunications public limited company
    Inventor: David Geoffrey Morrison
  • Patent number: 5751368
    Abstract: The apparatus and method described herein shows a system of determining the delay of a delayed version of a sequence of images with respect to a relatively undelayed version in a system which creates an output image signal from a plurality of input signals. The invention is also useful for comparing a given image to other images to determine the closest match, and thus the one of the plurality of input image sources from which an output image is taken.
    Type: Grant
    Filed: May 17, 1996
    Date of Patent: May 12, 1998
    Assignee: Pixel Instruments Corp.
    Inventor: J. Carl Cooper
  • Patent number: 5694174
    Abstract: In a television signal transmission system including a transmitter and a receiver, a reference signal has a phase angle between 0.degree. and 360.degree. within a single cycle. The phase angle of the reference signal is successively produced by a phase angle generator and transmitted from the transmitter and is reproduced by the receiver to be compared with a received phase angle. The phase angle is modified by a compensation phase angle obtained from a phase difference in the transmitter and the receiver. The reference signal may be either a color subcarrier signal or a sequence of sampling clocks.
    Type: Grant
    Filed: October 23, 1995
    Date of Patent: December 2, 1997
    Assignee: NEC Corporation
    Inventor: Norio Suzuki
  • Patent number: 5652749
    Abstract: Method and apparatus are provided for segmenting a multiple program multimedia digital data stream for transmission over a distribution communications network. Each program multimedia digital data stream includes sequential transport system (TS) packets with program clock references (PCRs) at a set time interval and a program identification (PID) associated with the PCRs. The multiple program multimedia digital data stream is received. The TS packets are decoded to identify the program clock references (PCRs). A selected number N of TS packets are identified. The multimedia digital data stream into frames responsive to both the identified number N of TS packets and the identified PCRs. A program identification (PID) associated with one of the PCRs is selected for timing the transmission of segmented multiple program multimedia digital data stream.
    Type: Grant
    Filed: July 25, 1996
    Date of Patent: July 29, 1997
    Assignee: International Business Machines Corporation
    Inventors: David William Davenport, Gary Scott Delp, Jeffrey James Lynch, Kevin G. Plotz, Philip Lynn Leichty
  • Patent number: 5572261
    Abstract: The apparatus and method described herein provides for detecting or measuring the relative timing of the audio and video portions of an audio visual program by inspection of the opening and closing of the mouth of a speaker, and comparing that opening and closing to the utterance of sounds associated therewith.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 5, 1996
    Inventor: J. Carl Cooper
  • Patent number: 5570372
    Abstract: A method and system in which lip synchronization is restricted to a single system in a multiple system communication of video data and audio data. In the preferred embodiment, the receiving system synchronizes video and audio signals for presentation. The originating system forms and processes video and audio signals separately. For many systems, the processing involves dissimilar delays. Consequently, when the information is transmitted through a network to the receiving system, the video and audio data is nonsynchronous. The originating system provides delay information that is indicative of the dissimilarity of video and audio processing time at the originating system. The delay information is utilized at the receiving system to determine an adaptive compensation delay for introduction at the appropriate video or audio processing path. By providing a single compensation delay for multi-system communications, the total delay is potentially reduced.
    Type: Grant
    Filed: November 8, 1995
    Date of Patent: October 29, 1996
    Assignee: Siemens Rolm Communications Inc.
    Inventor: Shmuel Shaffer
  • Patent number: 5537408
    Abstract: Method and apparatus are provided for transmitting a stream of multimedia digital data over a distribution communications network. A multimedia stream server segments the multimedia digital data stream into data blocks on a first boundary and a second boundary. The first boundary is a set number of transport system data packets and the second boundary is a transport system data packet including a timestamp. A scheduler schedules the segmented data blocks for transmission. The multimedia stream server decodes the segmented data blocks to locate the timestamps and matches the transmission of the located timestamp data block with a time value indicated by the timestamp. The set number of transport system data packets can be determined at connection setup and is not a predetermined value for all sessions. At the receiver, batch processing of received multimedia data can be provided.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: July 16, 1996
    Assignee: International Business Machines Corporation
    Inventors: Mark W. Branstad, Jonathan W. Byrn, Gary S. Delp, Phillip L. Leichty, Jeffrey J. Lynch, Kevin G. Plotz, Lee A. Sendelbach, Albert A. Slane
  • Patent number: 5533021
    Abstract: Method and apparatus are provided for transmitting a stream of multimedia digital data over a distribution communications network. A multimedia stream server segments the multimedia digital data stream into data blocks on a first boundary and a second boundary. The first boundary is a set number of transport system data packets and the second boundary is a transport system data packet including a timestamp. A scheduler schedules the segmented data blocks for transmission. The multimedia stream server decodes the segmented data blocks to locate the timestamps and matches the transmission of the located timestamp data block with a time value indicated by the timestamp. The set number of transport system data packets can be determined at connection setup and is not a predetermined value for all sessions. At the receiver, batch processing of received multimedia data can be provided.
    Type: Grant
    Filed: February 3, 1995
    Date of Patent: July 2, 1996
    Assignee: International Business Machines Corporation
    Inventors: Mark W. Branstad, Jonathan W. Byrn, Gary S. Delp, Philip L. Leichty, Jeffrey J. Lynch, Kevin G. Plotz, Lee A. Sendelbach, Albert A. Slane
  • Patent number: 5530483
    Abstract: The apparatus and method described herein shows a system of determining the delay of a delayed version of a sequence of images with respect to a relatively undelayed version. The system operates to take multiple samples of the delayed and undelayed versions at approximately the same sample position on the image and to correlate these samples over multiple image frames to determine which of a plurality of delayed images most closely match a given undelayed image. By knowing which delayed image frame most closely matches a given undelayed image frame it is shown to arrive at a coarse number of frames of delay. A fine delay measurement is achieved by adding a measure of the instantaneous frame to frame delay with respect to a known corresponding feature of the respective video type signals. The invention is also useful for comparing a given image to other images to determine the closest match.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: June 25, 1996
    Assignee: Pixel Instruments Corp.
    Inventors: James C. Cooper, Steven J. Anderson
  • Patent number: 5504931
    Abstract: A method and apparatus for generating a sequence of displacement vectors and associated minimal error values. The vectors and associated values represent the best match of a current block of elements of a first frame of a signal with one of a plurality of search blocks of elements located within a corresponding search window of a second frame. A first stream of data, representing the elements of the first frame is transmitted to a linear array of processing units; a second stream of data, representing the elements of the second frame is transmitted to the array; a hybrid stream of data from the elements of the second stream is synthesized such that the elements of the hybrid stream are aligned in time with the elements of the first stream so as to enable each processing unit of the array to compute an error between a particular current block and a different search block of the corresponding search window. The error is a measure of the difference between two blocks of elements.
    Type: Grant
    Filed: May 10, 1995
    Date of Patent: April 2, 1996
    Assignee: Atmel Corporation
    Inventor: Frederick C. Furtek
  • Patent number: 5483292
    Abstract: Digital data having a symbol rate that is a multiple of horizontal scan rate are buried in broadcast television signals. In a digital signal receiver the data are separated from composite video signal by quadrature video detection followed by comb filtering. The comb filtering is most economically realized by digital sampling at symbol rates. The regeneration of clocking signals at symbol rate, and at multiples of symbol rate where oversampling analog-to-digital conversion (ADC) techniques are employed, is done using a controlled oscillator with automatic frequency and phase control (AFPC) responding to the horizontal synchronizing pulses transmitted in the broadcast television signals. The horizontal synchronizing pulses are usually much larger than noise, so the controlled oscillator frequency and phase is rapidly adjusted following energization or channel change of the digital signal receiver.
    Type: Grant
    Filed: March 9, 1994
    Date of Patent: January 9, 1996
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jung-Wan Ko
  • Patent number: 5473638
    Abstract: A method and apparatus provide an equalization time delay to synchronize a plurality of paging transmitters in a simulcast paging system. A delay equalization circuit (41 ) appropriate for use with an analog input signal includes a coder/decoder (CODEC) (50) and a digital signal processor (DSP) (58). An analog input signal is digitized or sampled by an analog-to-digital converter (ADC) in the CODEC, producing corresponding digital values that are input to the DSP. The DSP employs a selected finite impulse filter to interpolate between the sampled digital values from the CODEC to provide enhanced resolution in delaying a signal output that is output. The DSP determines a major sample index and an interpolated filter index to achieve the desired equalization time delay. These variables define two delay intervals that are combined to provide the required equalization time delay.
    Type: Grant
    Filed: January 6, 1993
    Date of Patent: December 5, 1995
    Assignee: Glenayre Electronics, Inc.
    Inventors: Robert F. Marchetto, Todd A. Stewart
  • Patent number: 5434615
    Abstract: A signal processor apparatus is adaptable to electronic endoscopes having different lengths without the need for changing the operation timing when sampling a video signal. A sampling pulse generator incorporating a phase varying means is disposed in the operating portion or the connecting portion (setup board) of an electronic endoscope. A sampling pulse having the timing corresponding to the length of the electronic endoscope is formed by varying the phase of the sampling pulse by the phase varying means. The sampling pulse generator may be disposed together with a sample-and-hold circuit, a driving circuit of a CCD and the like. Since it is possible to sample and hold the video signal by using the sampling pulse which is correspondent with the length of the electronic endoscope, effective picture signal processing by the processor apparatus is enabled.
    Type: Grant
    Filed: September 13, 1993
    Date of Patent: July 18, 1995
    Assignee: Fuji Photo Optical Co., Ltd.
    Inventor: Seizi Matumoto
  • Patent number: 5430886
    Abstract: A method and apparatus for generating a sequence of displacement vectors and associated minimal error values. The vectors and-associated values represent the best match of a current block of elements of a first frame of a signal with one of a plurality of search blocks of elements located within a corresponding search window of a second frame. A first stream of data, representing the elements of the first frame is transmitted to a linear array of processing units; a second stream of data, representing the elements of the second frame is transmitted to the array; a hybrid stream of data from the elements of the second stream is synthesized such that the elements of the hybrid stream are aligned in time with the elements of the first stream so as to enable each processing unit of the array to compute an error between a particular current block and a different search block of the corresponding search window. The error is a measure of the difference between two blocks of elements.
    Type: Grant
    Filed: June 15, 1992
    Date of Patent: July 4, 1995
    Inventor: Frederick C. Furtek
  • Patent number: 5387943
    Abstract: A semiautomatic lip sync recovery system for time synchronizing the audio and video channels of a television signal uses programmable delay circuits in each channel. An area of the image represented by the video channel is defined within which motion related to sound occurs. Motion vectors are generated for the defined area, and correlated with the levels of the audio channel to determine a time difference between the video and audio channels. The time difference is then used to compute delay control signals for the programmable delay circuits so that the video and audio channels are in time synchronization.
    Type: Grant
    Filed: December 21, 1992
    Date of Patent: February 7, 1995
    Assignee: Tektronix, Inc.
    Inventor: David S. Silver
  • Patent number: 5371535
    Abstract: A compact and low-cost multiplexing apparatus for a plurality of high-efficiency encoded image signals is capable of improving an image quality and of shortening a transmission delay time. The multiplexing apparatus for an image signal includes delay compensating circuits provided corresponding to a plurality of image terminals, for storing image encoded signals sent from the respective image terminals; a control circuit for performing a control to form a large frame signal from small frame signals whose number is equal to at the most the number of image signal sources, by detecting frame head codes from input/outputs of the delay compensating circuits, thereby not being duplicated from a plurality of delay compensating circuits, and also adding circuit for adding a frame start code to each of large frames. Even when the frame rates are different between terminals, since all of the image encoded signals are not decoded but multiplexed, deterioration of image qualities and transmission delays can be reduced.
    Type: Grant
    Filed: January 15, 1993
    Date of Patent: December 6, 1994
    Assignee: Hitachi, Ltd.
    Inventor: Masaaki Takizawa
  • Patent number: 5371540
    Abstract: In the present invention, a drive circuit 12 drives a solid-state image-pickup element 11 in synchronism with a synchronizing signal generated by a synchronizing signal generation circuit 13, and the solid-state image-pickup element 11 issues an output signal prior to an end time of a horizontal blanking period by a time period T.sub.A. This output signal is processed in a digital signal processing circuit 14 and is issued as a picture signal. At that time, the picture signal is delayed from the synchronizing signal by a time period (T.sub.B -T.sub.A) owing to the signal processing, whereas the synchronizing signal is delayed by a delay circuit 15, in which a delay time made by subtracting a time period T.sub.A from a delay time T.sub.B of the digital signal processing circuit 14 is given, and can be issued in a proper timing for a picture signal output of the digital signal processing circuit 14.
    Type: Grant
    Filed: October 8, 1993
    Date of Patent: December 6, 1994
    Assignee: Matsushita Electric Industrial Co.
    Inventors: Akihiro Tamura, Atsushi Morimura, Yoshinori Kitamura