| 摘要 |
PURPOSE:To enable the acquisition of plural variable powers even with a single lens by driving the lens and an optical path changing means and setting a magnification based on a command. CONSTITUTION:After an original platen 1 is at first positioned so that a chart 20 may be positioned just under a light source 3 and the light from the light source 3 is made transmitted to the center location of the chart 20, reflected on a mirror 4 and mirrors 31, 32 of a Mueller unit 30, and the image of a center location is projected on a CCD 8 via a lens 50. When any magnification is commanded by a magnification command circuit 49 in this state, a variable power is performed by starting a program within a control circuit 45 and by moving the unit 30 and the lens 50 up to the location in accordance with the commanded magnification by driving motors 42 and 43. But, the moving direction of the Mueller unit is determined to get the presence or absence of a pint coincidence and a focusing by performing a focus detection, using the output signal of the picture element in which either one of the focus detection patterns 22a to 22c in accordance with the commanded magnification is projected of the picture elements of the CCD 8, because the obtained target magnification is rough. |
