ORIGINAL SIZE DETECTION APPARATUS, ORIGINAL SIZE DETECTION METHOD, AND IMAGE FORMING APPARATUS

摘要

PPROBLEM TO BE SOLVED: To provide an image side detection apparatus with a short detection time, an image size detection method, and an image forming apparatus with a short image forming time. PSOLUTION: A CCD line sensor reads the image data of an original placed on an original platen glass plate of the image forming apparatus, adder circuits 1 receive the read data and sum the data for a prescribed time. Then respective averaging circuits 2 apply averaging processing to the sum data, and respective comparator circuits compare the averaged data with reference data to detect the size of original on the basis of a result of comparison. In this case, the size of the original is detected on the basis of positional information in which the output data are inverted with respect to the reference data among output data of each comparator circuit 3. PCOPYRIGHT: (C)2003,JPO