Redundant indicator for detecting neutral position of joystick member

The invention as set forth in claim 11, wherein:

• a) said control member comprises a joystick type control device comprising a joystick member, said joystick type control device having electrical output means characterized by parameters which vary in accordance with the displacement of the joystick member in said X-axis and Y-axis directions,
• b) said electrical output means being separate and distinct from said emitter-sensor means, and the electrical signal from said emitter-sensor means constituting an independent and redundant digital indicator for confirming when the joystick member is in solely its neutral position as opposed to its being displaced toward one of said other, non-central control positions in said X-axis and said Y-axis directions.

Control means comprising, in combination:

• a) a joystick type control device having a joystick member, said device having a plurality of electrical output means, one of said output means being characterized by parameters which vary in accordance with the angular displacement of the joystick member from a central, neutral position toward X-axis and Y-axis directions corresponding to control positions disposed on different sides of said neutral position,
• b) said joystick member having a light-reflecting area thereon which traverses a predetermined field of travel as the member is moved between its various positions, and
• c) another of said electrical output means comprising an emitter-sensor means constituted of a light source and a light sensor, said emitter-sensor means being disposed adjacent the field of travel of the light-reflecting area of the joystick member and producing a supplemental electrical signal that is separate and distinct from the signal of said one electrical output means, said supplemental signal being produced from reflected light which is initiated and emitted from the said light source and reflected from said reflecting area of the joystick member and onto the light sensor solely when the joystick member is disposed in its neutral position and not when the joystick member is displaced in either the said X-axis direction or the Y-axis direction.

In a joystick controller, the method of responding to the attainment by an elongate joystick which has a predetermined girth at one end, of a neutral position with respect to X-axis directions and Y-axis directions, which includes the steps of providing a reflective surface on a minute area of the joystick, said area being characterized by a cross-dimension which is less than the girth of the said one end of the joystick, placing the joystick in its neutral position, locating an emitter-sensor optical-electronic chip in a position spaced a fixed, predetermined distance from said reflective surface and at a point which is in direct axial alignment with the axis of the joystick solely when the joystick is disposed in its neutral position, electrically energizing the emitter portion of the emitter-sensor chip so as to transmit light toward the said reflective surface to be reflected back toward the sensor portion of the chip, and monitoring the electrical response of the sensor portion of the chip to indicate lateral displacement of the joystick away from its neutral position and toward one of said X-axis directions or said Y-axis directions, said change resulting from movement of said reflective surface to a position directed away from said chip.