| 摘要 |
The device includes two photoelectric assemblies disposed in X and Y directions and turned by a track ball 1 via two drive wheels 2, each photoelectric assembly consists of a grid wheel 3, a light source (not shown) on one side of the grid wheel, and a mono-chip incorporated photoelectric transistor (not shown) on the opposite side of the grid wheel the photoelectric transistor being induced to produce high/low voltage signals according to light-transmission and light-absorption for converting into respective pulse signals by a central processing unit for controlling the movement of a cursor on a display screen. In other embodiments the sequential spacing between grid wheel holes on the grid wheel hole widths are proportionally varied (figures 4 and 5). <IMAGE>
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