| 摘要 |
PURPOSE:To focus with a simple constitution and fine accuracy by arranging a transverse photoelectric effect element at an imaging point of a subject to be pickupped. CONSTITUTION:A beam of light 1 from a subject is led on a transverse photoelectric effect element 5 through the first optical device 4 having a slit 2, a fixed mirror 3, etc., to form the first detected image 7. On the other hand, a beam of light 8 from the subject is led on the element 5 through the second optical device 11 having a slit 9 and a moveable mirror 10, to form the second detected image 12. The element 5 has P-N junction between a P type area 22 and N<+> type surface layer and when a detected image 12' is not located on a symmetrical position to a center axis 23, voltage is generated at electrodes 17, 18, allowing the output to be inputted via a signal processing device 16 and a controller 19 to a driving source 21. The moveable mirror 10 and a lens 13 move, and the movement stops when the image 12 and an image 7 fell onto a symmetrical position, thereby it is focused. Through the process focusing with a simple constitution and higher accuracy are obtained. |
