| 摘要 |
PURPOSE:To enable discrimination of presence or absence of an original and its size to be automated, by providing electrodes or photodetectors opposite to each other outside the copying region of an original platen glass. CONSTITUTION:Electrodes X1, Y1, and X2, Y2 are provided each opposite to each other on nonimage region A of glass 2 of original platen 1 and on original pressing cover 3. A detection signal of an original size is obtained by detecting conduction or nonconduction of electrodes X, Y disposed thus. For example, when the original is absent, electrodes X1-Y1 and X2-Y2 become conducting, and when it is of A4 size, electrodes X1-Y1 become conducting but X2-Y2 nonconducting. When it is of A3 size, electrodes X1-Y1 and X2-Y2 become both nonconducting. In addition, photodetectors are used in place of electrodes X, Y, a size of a thick original can be detected. |
