Joystick with uniform center return force

摘要

A computer joystick capable of detecting the position of a control stick in the X and Y directions, as well as the rotational (R) position of the control stick to allow three positional measurements to be made. The joystick uses an optical position detection circuit with a pair of light sources mounted either on the control stick or a printed circuit board mounted beneath the control stick. A photodetector assemble is mounted opposite the pair of light sources to detect light from the light sources. The distribution of the light intensity is indicative of the position of the control stick in the X, Y, and R directions. A single coil spring is used to return the control stick to a resting position when released by the user. The single spring provides an even return force that is dependent on displacement from the resting position. The bottom portion of the control stick moves in a three dimensional arcuate path as the control stick is manipulated by the user. To simplify operation of the optical position detection circuit, the joystick uses a mechanical three dimensional to two dimensional mechanical converter assembly to convert the arcuate movement of the control stick to two dimensional movement of the light sources.