Abstract: In a data filing system, a data input unit converts an input document into an electrical image signal. A data processing unit sequentially performs multi-step image compression processing including a pattern recognition step. The processing unit includes subprocessors which independently execute corresponding image compression processing of higher processing levels. A data storage unit has a hierarchical memory structure, so that, when it receives compression image data of a given image processing level from the processing unit, it can store this data in accordance with its image processing level. A system controller causes, in the document registration mode, the first subprocessor of the data processing unit to execute image compression processing of a first level, and causes the data storage unit to store the resultant compression image data.

Abstract: A multi-layered solid state image sensor senses a three-dimensional optical image introduced through a lens having a constant focal length and a constant focal depth. The image sensor has a plurality of transparent layers stacked together with reflection preventive coating films sandwiched therebetween. A cell matrix is provided on each of the transparent layers. Cells included in each cell matrix are arranged so as not to overlap each other so that image light can effectively reach the lowermost layer. The cell matrices defining imaging surfaces on the stacked transparent layers become operative simultaneously for image sensing. Therefore, just-focused image planes at different focal points are formed on the cell matrices.

Abstract: An image processing device which processes a small region of a predetermined number (m.times.n) of picture elements in a two-dimensionally scanned image and successively obtaining accumulated output of picture element data of a new small region containing a new picture element each time the new picture element data is read out. The sum of data of n consecutive picture elements of each row in an array of (M.times.N) picture elements is obtained, and is updated every time a new picture element of the corresponding row is read. The accumulated sum of the picture element data of a small area having (m.times.n) picture elements is obtained, and is updated every time new picture element data is read, thereby obtaining the accumulated sum of new (m.times.n) picture element data.

Abstract: This disclosure concerns to apparatus for reading drawings. The apparatus of this invention is an apparatus for reading symbols on a drawing wherein the drawing comprises a preprinted lattice pattern with orthogonal lines forming unit rectangular areas and each symbol or portions thereof is drawn within one or more of the unit area each symbol is drawn so that the portion of the symbol within a unit area has a predetermined size and position with respect to the sides of the unit area.