Abstract: An image reader for a facsimile apparatus or like image processing apparatus of the type having a line image sensor. A plurality of serial connections of a photodiode and a switch are arranged in an array in the line image sensor and divided into a plurality of discrete blocks by each predetermined number. The output of each of the blocks is applied to an analog adder the output of which is delivered as an image signal. The analog adder replaces switching means adapted for switching actions so as to eliminate switching noise otherwise entailed by the switching actions.

Abstract: In an apparatus for reading an image of the document fixedly placed, the document's position, size, etc. is automatically decided. Linear light sources are arranged on a pressure plate in a position on the back side of the document in both the main scanning direction and the sub-scanning direction, and the presence or absence of lights from those light sources is monitored by a sensor arranged on the side facing the document to decide the presence or absence of the document. The sensor comprises a one-dimensional solid scan type image pickup device for reading images, and another sensor for receiving the light coming from the position locating ahead the scan position currently detected by the image pickup device.

Abstract: A light source capable of producing intermittent flashes of light is used as a light source for illuminating an original. The light source is triggered in response to the read signal and a self-scanning type array of light receptors accumulates the charge representative of a light image focused thereon. In synchronism with the triggering of the light source, the video output is derived from memory means which stores the charge thus accumulated.

Abstract: For facsimile transmission or the like an optical system scans an original document and produces quantized electrical signals which are stored in a buffer memory. A data compression unit reads out the signals and performs data compression thereon asynchronously with storage of the signals in the buffer memory. The data compression rate decreases in accordance with the proportion of high density areas of the document, and the electrical data signals accumulate in the buffer memory. The scanning speed is automatically decreased as the amount of signals in the buffer memory increases so that the scanning speed is controlled to correspond to the data compression rate.

Abstract: A document to be scanned is placed on a fixed transparent cylindrical platen and a mirror is totatable about the axis of the platen. A linear or single line cathode ray tube is fixed in position to produce a light beam which is reflected from the mirror onto the document and moves along the surface of the document in a main scan direction. A light receiving unit comprising a fibre optic bundle and a photoelectric generator is arranged parallel to the main scan direction to receive the light beam reflected from the document. Drive means are arranged to rotate the mirror and move the receiving unit so that the light beam is displaced in the subscan direction perpendicular to the main scan direction and the receiving unit is moved in synchronism therewith.