| 摘要 |
<p>A Friedmann analyser with an arrangement of fixed and rotatable shutters (6, 8) for displaying different patterns of light spots to a subject has a screen (20) for displaying to the operator each light spot pattern selected by illumination of a series of light-emitting elements (22) at fixed positions over the screen area. The light-emitting elements are actuated by a fixed array of infra-red emitting and receiving elements (26) that direct radiation onto a binary-coded reflective pattern (24) displaceable with the rotatable shutter (8) and sense the radiation reflected by said pattern so that with the displacement of the shutter different reflected code signals are sensed associated with respective shutter light patterns displayed to the subject.</p> |
