| 摘要 |
The coder controls the rotation of a monochromator in a spectrophotometer and has a code carrier comprising two or more code drums (2, 3). Each drum bears a punched code on its surface and is rotated beneath scanning heads by a system of gears. The gear mechanism is such that the ratio between the speeds of the drums is constant. The code formed on the surface of each drum consists of optically transparent and opaque regions illuminated by light sources inside the drum. The scan heads (16) consist of light detectors facing the light sources through the coded surface of the drum. |
