| 摘要 |
A light pen for the screen of a video unit has a tubular casing, 1 accommodating a photoelectric element 4, an electric switch 5b, 6b, and a sensing tip 3 which can be displaced axially to actuate the switch. Two printed circuit boards 5, 6 mounted transversely of the casing carry the opposite poles 5b, 6b of the switch, and the two boards are movable towards one another to produce switch contact against the bias of a helical spring 7 which surrounds the two poles and which also makes electrical connection between peripheral parts of the two boards. The photoelectric element is mounted on one of the circuit boards nearer to the sensing tip. <IMAGE>
|
