Abstract: A gain control signal is produced according to the difference in level between the signal obtained by scanning the white reference plate and the previously stored standard signal. Based on the gain control signal, the amplification level of the signal obtained by scanning the document is adjusted by a gain controller, and then the resulting signal is converted into a digital signal and supplied outside.

Abstract: An apparatus including an integrated circuit for processing analog image signals supplied from a CCD sensor. The integrated circuit has a photodiode line array between a pair of shift gates and a pair of CCD shift registers, in that order. The integrated circuit further includes logic that combines the respective output signals of the CCD shift registers as signals either in-phase or out-of-phase (in opposite phase) with respect to each other, and a selecting signal generating device to generate a signal that selects, or indicates the selected, one or the other of the two combinations.

Abstract: There is a sorting apparatus for mixed envelopes according to whether or not the envelopes are face-up, and whether or not they are upside-down. Each envelope is carried lengthwise and a parallel light beam is radiated on the envelope from the right and left oblique directions with respect to the carrying direction of the envelope. When the light beam is radiated on the backside of the envelope from the upper side of the envelope, the shadow of the flap is formed on the envelope. Whether or not the envelope is face-up and whether or not the envelope is rightside-up is determined by this shadow detection.

Abstract: Analog switches are connected between corresponding photodiodes and a common output line. The analog switches are sequentially scanned in response to scanning pulses. During the ON period of each scanning pulse, the corresponding analog switch is turned on twice. A first circuit produces a first signal, including an image signal component and a noise signal component, when the analog switch is turned on for the first time, and produces a second signal including only the noise signal component, when the analog switch is turned on for the second time. A second circuit produces the signal derived from the difference between the first and second signals, i.e., the image signal.

Abstract: An optical character reader comprises a pre-scanner and a main scanner. The pre-scanner coarsely scans the surface of a postal item and generates video signals representing a postal item pattern. The pattern is divided into a plurality of blocks. Of these blocks, a destination address block, for example, is selected. The coordinates of the lower side of the destination address block are determined. According to the coordinates a limited area of the destination address block is determined, which is to be scanned by the main scanner. The main scanner scans finely the limited area and generates high resolution video signals. According to the high resolution video signals a postal code in the destination address block is detected and recognized.

Abstract: A postal code pattern video signal obtained by optically scanning the postal code area is converted, by a quantitizing circuit, into binary data, i.e. single bit pattern data. The video signal is also converted into multibit pattern data by a A/D converter. The single and multibit pattern data are stored in the single and multibit pattern memories, respectively. The single bit pattern data is masked by the character detecting circuit to set an address of a mask corresponding to chained characters. The multibit pattern memory is designated by the address, so that the multibit pattern data corresponding to the chained characters is read out. The words of multibit pattern data are accumulated for each line, and the lowest level data is detected from the accumulated data as the connecting portions. At the connecting portion, the chained character is separated.