Abstract: Light which bears image information carried by a subject is two-dimensionally read through tricolor separating optical systems with linear image sensors for the three colors R, G, B. Odd- and even-numbered pixel signals outputted from the linear image sensors 1 are alternately read to produce an image signal which comprises a series of pixel signals. The image signal is corrected successively by an offset level corrector, a sensitivity variation corrector, an auxiliary scanning curvature/odd- and even-numbered pixel level difference corrector, a main scanning aberration/magnification corrector, and a luminance-to-density conversion corrector, thereby producing an image signal for producing a high-quality reproduced image.

Abstract: An offset level of a pixel signal outputted from a linear image sensor having a pixel transfer array disposed along a photodetector is corrected by outputting as empty transfer levels signal levels produced from empty pixel transfer array elements when transfer clock pulses are successively applied to the pixel transfer array after one line of pixel signals is transferred from the photodetector through the pixel transfer array. To determine a correcting quantity of a given pixel of a predetermined line, a difference is produced by subtracting an average empty transfer level of a line preceding the predetermined line from an average empty transfer level of the predetermined line. A proportional distribution of the difference from a first pixel to an nth pixel to be corrected with respect all pixels of the predetermined line is determined. The proportional distribution is added to the empty transfer level of the line preceding the predetermined line.

Abstract: An image signal is produced by adding output signals from arrays of photoelectric transducer elements of adjacent two of a plurality of image sensors. Output signals from all of the image sensors are combined into an image signal representative of image information along one main scanning line. One of the output signals is gradually increased from an actual level thereof to a predetermined offset level in an interval during which the output signals start being added to each other. The other of the output signals is gradually reduced from the predetermined offset level to an actual level thereof in an interval during which the output signals stop being added to each other, whereby the output signals are smoothly combined with each other.

Abstract: A video signal frame search apparatus for selecting a frame from a video signal recorded on a magnetic tape, e.g. for supplying the frame to a video printer, is based on a system controller which controls playback and rewind operations of a VTR during a frame search operation. When a desired frame is displayed during such a frame search operation, actuation of a switch by the user causes a plurality of frames adjcent to and including the desired frame to be stored in a memory and then displayed simultaneously, enabling the user to specify to the system controller the precise position of the desired frame.

Abstract: An image signal is processed to grain digital image data by comparing digital random number data generated on the M-sequence coding theory and the digital image data with a binarizing digital comparator, and employing a signal produced by the comparison as grained binarized image data. The digital random number data are produced by a digital random number data generator comprising a random number generating circuit based on the M-sequences coding theory and an initial value presetting circuit for setting an initial value in said random number generating circuit.

Abstract: A laser beam source is driven to emit a laser beam for use in scanning an image recording medium in order to record image information thereon in a plurality of exposure areas. The areas are spaced at intervals in a scanning direction in which the image recording medium is scanned by the laser beam. A first current supply source is responsive to an exposure signal for supplying the laser beam source with an exposure current of a higher in level than a threshold level of the laser beam source. A second current supply source supplies a bias current to the laser beam source when the scanning position of the laser beam source is a linear distance ahead of an exposure start position for each area to be exposed, the first and second current supply sources being connected parallel to each other.

Abstract: A light beam scanning device includes a reference grid plate, a resonant light deflector for deflecting a light beam to cause the light beam to scan the reference grid plate through an f.theta. lens for thereby enabling the reference grid plate to produce a pulse signal, and a PLL circuit for generating a synchronizing signal from the pulse signal to read or record image information. The reference grid plate has slits defined at intervals, the slit intervals in that area of the reference grid plate which produces a pulse signal that is not directly contributed to the recording or reading of the image information being progressively smaller toward an end of the reference grid plate according to the scanning speed of the light beam.

Abstract: A cylinder drive motor includes a magnetized annular member having a series of equally spaced apart alternating pole elements and an additional pole element located within an interval between successive ones of the pole elements of the series. The pole elements are detected by a single sensor and a sinusoidal signal is generated having a series of higher-amplitude peaks successively occurring in correspondence with the pole elements of the series and a lower-amplitude peak occurring within an interval between successive ones the higher-amplitude peaks in correspondence with the additional pole element. The sinusoidal signal is compared with first and second reference levels to generate a speed-related pulse signal representative of the frequency at which the higher-amplitude peaks cross the first reference level and a phase-related pulse signal representative of the timing at which said lower-amplitude peak crosses the second reference level.