Abstract: A bidirectional digital signal transmission system includes a transmission line, and video instruments respectively connected to both ends of the transmission line. In each of the video instruments, a digitized signal is multiplexed on a time division basis and compressed in a time base, thereby generating a transmission signal constituted by repetition of a signal period and a quiescent period. The transmission signal generated by one of the video instruments is transmitted during the quiescent period of the transmission signal generated by another one of the video instruments, thereby realizing bidirectional digital signal transmission. The system further includes a repeater circuit inserted in the transmission line at an intermediate location thereof to compensate for deterioration of the signal occurring during transmission over the transmission line. The repeater circuit includes a switch device for preventing a transmission signal feedback loop from being formed in the repeater circuit.

Abstract: A spread spectrum communication method includes the steps of measuring a parameter indicative of a C/N value of a received signal at one station during a communication between stations remote from each other in accordance with a spread spectrum communications scheme, and changing the data rate of a signal to be transmitted from another station when the C/N value changes by a predetermined value or more.

Abstract: In a video signal transmission method and system wherein a signal containing a video signal is bidirectionally transmitted and received in a substantially real time in video appliances coupled via a transmission path to each other, a digital signal containing a digital video signal is time-compressed, and a transmission operation is controlled in such a manner that a transmission period and a no transmission period are alternately produced in a preselected period. Then, the time-compressed digital signal is transmitted to the transmission path during the transmission period, whereas another digital signal transmitted via the transmission path from the video appliance on the counter side is received during the no transmission period. Then, the received digital signal is time-expanded to reproduce the original signal.

Abstract: In a video signal transmission method and system wherein a signal containing a video signal is bidirectionally transmitted and received in a substantially real time in video appliances coupled via a transmission path to each other, a digital signal containing a digital video signal is time-compressed, and a transmission operation is controlled in such a manner that a transmission period and a no transmission period are alternately produced in a preselected period. Then, the time-compressed digital signal is transmitted to the transmission path during the transmission period, whereas another digital signal transmitted via the transmission path from the video appliance on the counter side is received during the no transmission period. Then, the received digital signal is time-expanded to reproduce the original signal.

Abstract: A method and an apparatus for digital signal recording and/or reproduction are disclosed in which tracks are formed sequentially on a recording medium by use of a head unit mounted on a rotary cylinder, an input digital data is recorded in the recording medium, and the digital data thus recorded is reproduced. The input digital data is modulated into a code word having at least d (d: an integer of at least two) successive bits of high- and low-level data in a signal waveform recorded in the recording medium. The timebase of the code word is compressed. The compressed code word is recorded in the tracks of the recording medium by use of the head unit. The code word recorded and compressed in the recording medium is reproduced. The timebase of the reproduced code word is expanded, and the input digital data is reproduced from the expanded code word.

Abstract: A picture signal encoding multiplexing method and apparatus in which encoded data of a plurality of picture signals, which are respectively output from a plurality of picture signal encoding processing units, is multiplexed in a channel multiplexing unit. The method includes the steps of: generating a transmission rate control signal corresponding to information related to the encoded distortion supplied from each of picture signal encoding processing units in a channel multiplexing unit, and supplying the transmission rate control signal to each of the picture signal encoding processing units; and outputting the encoded data of the picture signal from each of the picture signal encoding processing units in accordance with the transmission rate control signal.

Abstract: An image pickup apparatus for a television and a depth-of-field control apparatus used in the same. Image signals corresponding to a plurality of picture images different in focal point or length position are obtained by a mechanism for changing a focal point or length position to produce a new image signal by composing these image signals through a composition circuit, and motion information of an object is obtained by a circuit for detecting a moving portion in the object to control the image composition by the motion information. The focal point or length position is moved in synchronism with an integer multiple of a vertical scanning period of the television. The image signals corresponding to the plurality of picture images different in focal point or length position are obtained within one vertical scanning period determined by the system of the television. The amount of movement of the focal point or length position is controlled in conjunction with a value of a lens aperture of the camera lens.

Abstract: A replay equalization circuit for reproducing digital image information recorded on a recording medium includes a transducer for reading the digital image information, an equalization circuit connected to the transducer for equalizing an output of the transducer based on a speed information input, a clock recovery circuit connected to the equalization circuit for extracting a clock signal from an output of the equalization circuit for latching the output of the equalization circuit in response to the clock signal.

Abstract: A video signal transmitting method comprising: a sending method including the steps of: dividing an analog video signal in a unit corresponding to integer times of a number of bits composing an information field of one packet in packet transmission and converting into a digital video signal, forming a digitalized video signal into a plurality of packets, forming a plurality of packets into a first packet block in M lines.times.N columns, adding an error correction code which corrects a longitudinal error of data in a first packet block as a second packet block in P lines.times.N columns in an (M+1)th line and thereafter, and sending a packet; and a receiving method including the steps of: recomposing the same packet block as that composed on a sending side from plurality of received packets, recovering a video signal with packet loss information from an exchange and an error correction code formed into a packet, and regenerating an analog video signal from a digital video signal after recovery.

Abstract: An image pickup apparatus comprising: a two-dimensional filter for interpolating the registration discrepancy due to the chromatic aberrations of the lens used; and a two-dimensional filter for correcting the fixing discrepancy of an image pickup element. The registration discrepancy may be corrected by guiding video signals from the image pickup element through the two-dimensional filters.

Abstract: An adaptive transform encoder can keep a recording rate of a digital signal at a constant level.

Abstract: An original digital signal is converted into either a Miller-squared code signal or a Miller code signal, and undergoes serial-to-parallel conversion to produce n-phase signals (where n is desired to be a positive even number). N-phase virtual demodulated signals are simultaneously generated at clock timing having a period equivalent to 1/n times the period of the transmission clock. Out of the n-phase virtual demodulated signals, n/2 phases are selected to undergo parallel-to-serial conversion, the original digital signal being thus obtained.

Abstract: An optical tape apparatus having improved focus and tracking control. An optical head records, reproduces, or rewrites data on an optical tape by helically scanning the tape with a laser beam. A guide plate is disposed between the optical head and the tape to prevent the beam from becoming unfocused due to fluctuation of the tape cuased by an air film between the optical head and the tape. The optical head contains a semiconductor laser and an optical system exhibiting chromatic aberration for directing the laser beam onto the tape. The optical system includes a condenser lens for focusing the beam onto the tape. Fine focus control is achieved by changing the wavelength of the laser beam by directing part of the beam reflected from the tape back to the laser, thereby changing the focal point of the beam by virtue of the chromatic aberration of the optical system.

Abstract: An apparatus for recording an reproducing a digital video signal is disclosed which includes n sampling circuits each for performing a sub-Nyquist sampling operation for the digital video signal in such a manner that the amount of data is reduced to one-n-th of an original amount (where n is a positive integer) and a pixel sampled by the sub-Nyquist sampling operation is not sampled by the remaining sampling circuits, recording/reproducing means for recording and reproducing information at all or part of pixels which are sampled by the n sampling circuits and a device for reconstructing the digital video signal from reproduced information at pixels with the aid of a synthesizing technique or interpolation technique.

Abstract: This invention relates to a television camera and more particularly to a solid-state television camera using a solid-state image pickup device. The object of the invention is to provide a solid-state television camera which is devoid of drop of dynamic resolution for a moving object and provides high S/N for a still object. The solid-state television camera of this invention is equipped with pixels 3 from which signals are read out with a predetermined signal storage time, means 21 for detecting motion of an object from the signals of the pixels 3, and pixels 4 from which the signals are read out in the signal storage time in accordance with the detection signal of the detection means 21 l and outputting video signals. The present invention can obtain video signals free from the drop of dynamic resolution for a moving picture and video signals having high S/N for a still picture. As a result, the invention can provide a television camera having excellent picture quality as a whole.

Abstract: An original code series containing a synchronizing code is divided into code series, n in number so as to reduce an operation rate to 1/n (n is a positive integer). The detection of a synchronizing pattern is conducted on the basis of a fact that an original synchronizing pattern is transformed into any of patterns of n kinds based on the phase of division.

Abstract: A digital recording and reproducing system wherein luminance signals digitized and converted into the low speed signals and chrominance signals digitized at the time of recording are distributed among a plural number of channels and the signals of the plural number of channels are recorded respectively on a recording medium. At the time of the reproduction, the signals of the plural number of the channels are reproduced respectively from the recording medium and combined to form the luminance signals and the chrominance signals respectively. The luminance signals in the combined signal are converted into a high speed signal and output terminals for outputting dubbing signals from the system for dubbing the signals are led. The output side of a low speed-to-high speed converter and a channel combination circuit.

Abstract: Disclosed is an apparatus in which a picture signal is converted into digital signals and the digital signals are recorded into a recording medium, and which is suitable to perform dubbing of the digital signals reproduced from the recording medium. The apparatus employs the component method in which a luminance signal and chrominance signals constituting a picture signal are recorded separately from each other. According to the component method, the sampling frequency of the chrominance signal is set to be about 1/3-1/4 of that of the luminance signal, and therefore the recording/reproducing of a picture signal is carried out after the bit rate of the digital luminance signal is converted into a value equal to the bit rate of the digital chrominance signal.

Abstract: Video signal components including the luminance and color signals are sampled using a clock generator and dividers, and the resultant signals are coded through a plurality of channels and are recorded in a video tape recorder. In order to suppress and disperse in the screen image the effect of an error or a dropout occurring in a channel during a recording/playback process, the coded pixels are distributed to each channel so as to uniformly disperse the pixels associated with each component in the screen image. For this purpose, the pixels on a line perpendicular to the scanning lines on the screen are extracted sequentially from a different channel; consequently, even if a failure takes place in a channel, the erroneous pixel can thus be compensated for by use of the correct pixel just above or below the erroneous pixel.

Abstract: Number data affixed to individual digital data divided into a plurality of data blocks are sequentially read out from a recording medium to be used for determining the write-in positions of the digital data in a memory. For determining the write-in positions of the digital data, the number data of the next write-in position is estimated on the basis of the number data of the current write-in position. Judgment is made as to whether or not the number of times of continuous non-coincidence between the estimated number data and the successively read-out number data exceeds a predetermined setting, and, also judgment is made as to whether or not the number data read out each time falls within a predetermined range. Depending on the results of these judgments, one of the read-out number data and the estimated number data is selected to determine the next write-in position.