Abstract: The white peak level and black peak level of each of three types of color signals R, G and B obtained by picking up a negative image are detected. The amplitudes and levels of the signals are adjusted in such a manner that the white peak levels of the color signals R, G and B coincide as well as the black peak levels of these color signals. Signals representing the detected white peak and black peak levels are superimposed in first-half and second-half portions of a blanking interval of each of the color signals R, G and B. The signals that result can be utilized in subsequent signal processing. Also, the input/output characteristics of a gamma correction circuit are represented by an exponential function, which is for a gamma correction, up to a fixed input range, and by a KNEE curve, whose slope is smaller than that of the exponential curve, in a range beyond the fixed input range.

Abstract: The white peak level and black peak level of each of three types of color signals R, G and B obtained by picking up a negative image are detected. The amplitudes and levels of the signals are adjusted in such a manner that the white peak levels of the color signals R, G and B coincide as well as the black peak levels of these color signals. Signals representing the detected white peak and black peak levels are superimposed in first-half and second-half portions of a blanking interval of each of the color signals R, G and B. The signals that result can be utilized in subsequent signal processing. Also, the input/output characteristics of a gamma correction circuit are represented by an exponential function, which is for a gamma correction, up to a fixed input range, and by a KNEE curve, whose slope is smaller than that of the exponential curve, in a range beyond the fixed input range.

Abstract: A horizontal synchronizing reference signal producing circuit produces an internal horizontal synchronizing reference based upon an inputted clock and a reset pulse, a phase comparator compares the phases of a given external horizontal synchronizing reference and an internal horizontal synchronizing reference outputted by the horizontal synchronizing reference and generates a voltage signal conforming to a difference between the two compared phases. A low-pass filter then passes low-frequency components of the voltage signal outputted by the phase comparator, a VCO, whose frequency is controlled by an output voltage signal from the low-pass filter, generates a clock applied to the horizontal synchronizing reference signal producing circuit, a decision circuit determines whether the phase difference between the internal and external horizontal synchronizing reference signal lies within a range in which follow up is capable of being performed by the VCO.

Abstract: An image display system in which a plurality of magnetic recording/reproducing apparatus can be controlled via interfaces by a computer. The computer is adapted to output specification data for specifying one or more magnetic recording/reproducing apparatus to be controlled as well as control data including at least data on the shift of one or more magnetic recording/reproducing heads of the magnetic recording/reproducing apparatus to be specified. Each interface decodes the data input from the computer and transmits a given piece of control data to the magnetic recording/reproducing apparatus specified. The specified magnetic recording/reproducing apparatus shifts the magnetic recording/reproducing head in the radial direction of a rotating magnetic recording medium in accordance with the data on the shift of the magnetic recording/reproducing head applied through the above interface, and records signals into an arbitrary track or reproduces signals from an arbitrary track.

Abstract: Disclosed is an apparatus for gaining high-speed random access to a track in a magnetic recording/playback system of the type in which a magnetic head is shifted to an adjacent track in response to a forward-feed/reverse-feed signal and the head is positioned at the center of this track by tracking control. When the track number of a track to be accessed is designated, the designated track number is compared with a track number at which the magnetic head is presently located. An apparatus is provided for fast-feeding the magnetic head to a track adjoining the designated track on the basis of the comparison, and for subsequently outputting the forward-feed/reverse-feed signal for the purpose of tracking control.

Abstract: Disclosed is an apparatus for gaining high-speed random access to a track in an existing magnetic recording/playback system of the type in which a magnetic head is shifted one track at a time to an adjacent track in response to a forward-feed/reverse-feed signal and the head is positioned at the center of this track by tracking control. When the track number of a track to be accessed is designated, the designated track number is compared with a track number at which the magnetic head is presently located. An apparatus is provided for fast-feeding the magnetic head to a track adjoining the designated track on the basis of the comparison, and for subsequently outputting the forward-feed/reverse-feed signal for the purpose of tracking control.