摘要 |
The photoelectric coordinate-input device has two photoelectric arrangements which are respectively arranged in the X and Y direction and are rotated by a trackball (1) via two drive wheels (2), each photoelectric device having a cage wheel (3) having a series of openings (31) along its circumference, between which a series of screening walls (32) is alternately arranged. In addition, a light source (4) is arranged on one side of the cage wall and a photoelectric transistor (5) built into a single chip is arranged on the opposite side, the transistor receiving light from the light source (4) via the opening (31) in the cage wheel (3). The photoelectric transistor (5) produces high and low voltage signals, corresponding to transmission or blocking of light, which are converted by a central-processing unit into corresponding pulse signals, in order to control the movement of a cursor on a display or screen. <IMAGE>
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