| 摘要 |
<p>The circuit is for measuring the contrast in an optical image independently of focussing and directional parameters, using various arrays of photosensitive elements. The basic idea is to measure the light contrast difference between many different pairs of points on the image surface, using photodiodes, and to produce a voltage representation of a combination of these voltages. The simplest form of the basic diode pair combination is two back to back connected (1, 2), with the difference current measured with a suitable meter (AV). Other configurations involve three diodes (5, 6, 7) or two transistors. Groups of this kind are built up into a serial array of typically four groups (8, 9, 10, 11) connected axially and geometrically arranged in a square formation. Other arrangements using four diodes only (12, 13, 14, 15) or three diodes (17, 18, 19) are also possible.</p> |
