| 摘要 |
<p>A computer control includes a control device (50) which can be mounted in a separate unit, or can be mounted in a computer keyboard (64) with a finger-grippable element (60) movable in the plane of the keys (56), for controlling movement of a cursor (310) on a computer display (312). Included in the disclosure are features, such as the provision of a pair of members (96, 98), coupled to the finger element for mouvement orthogonally within a housing and having respective light gratings (184, 226) which are utilized to operate digital circuitry providing data of the element position; the provision of a friction means (156, 158) to retard motion corresponding to cursor up and down movement to reduce line jumping during horizontal movement; the provision of an automatic counter (472) controlling parallel resistance (482, 483, 484, 485) to control the gain of light sensing element (212) to eliminate circuit calibration; the provision of multiple gray level coding in plural regions (1220, 1222, 1224, 1226) of patterns (1218, 1230) spaced in two dimensions wherein decoding of the gray levels indicates position of the finger element; and the provision of operator-controlled switch facilities associated with the finger element for selecting one of at least two modes of cursor movement such as small (1260) and large (1258) increment modes of cursor movement.</p> |
