Information input apparatus

Claim 1

Sheet type of recognition apparatus comprising: optical scanner means for reading a sheet containing optical information and generating electrical information signals therefrom; a memory for storing said information signals; and a controller coupled to said memory and including a central processing unit, a binary coding circuit, a counter and an arithmetic operation circuit for automatically determining whether said information comprises an OMR code sheet, an OCR code sheet, a document sheet, or a mixture thereof, said controller determines sheet information sequentially in first and second orthogonal directions, said controller senses the occurence of an OMR or OCR code along said orthogonal direction and finding none determines that the sheet comprises a document sheet and in the event one of the said codes is found, causes information contained thereat to be read, said code comprises an OMR code and said controller operates to detect a timing mark on said sheet in X and Y directions by first sensing a dark timing mark in one of said directions, sensing a light portion of the sheet in the same direction, calculating the width dimension of the timing mark, determining whether the width dimension of the timing mark is located within a predetermined region of the sheet, repeating the process for another timing mark, and determining if there is a predetermined separation distance between the timing marks so that a predefined pattern is sensed from which the sheet is judged to be an OMR sheet, otherwise it constitutes a document sheet and then repeating the aforesaid operation for the other of said directions.