| 摘要 |
PURPOSE:To obtain a signal of an appropriate image data irrespective of a reflection type by discriminating automatically whether an image source by a laser beam is the reflection type or the transmission type. CONSTITUTION:As for a laser beam of a laser diode 23, its intensity is modulated in accordance with a density of a picture element of a scan position of a source 1. It is converted to a signal St of an image data by a condenser lens 81 and a photodetector 82 which are positioned at the opposite side of a mirror of the image source 1, as a read means 80, and supplied to a switching circuit 86 through an amplifier 83. Also, the read means 80 is converted to a signal Sr of the image data by a mirror 28 and a photodetector 84, and supplied to a switching circuit 86 through an amplifier 85. The signal St and Sr are supplied to level detecting circuits 91, 92, respectively, each peak-to-peak level signal is fetched, both these signals are compared by a comparing circuit 93 and supplied to the switching circuit 86, and the signal of a larger level is fetched and becomes a signal of the image data.
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