Rotary circuit control devices with changeable graphics

A control device for an electrical circuit which control device comprises:

• a base member and a movable member attached thereto which movable member is manipulated by an operator to change a setting of said control device, said base member being affixed to an electronic image display screen at a location which is at least partially within an image display area thereof,
• a display screen controller coupled to said image display screen and being conditioned to cause display of an image which conveys information pertinent to operation of said control device,
• a signal producing circuit situated at said location and which requires input of an electrical voltage, and
• a photovoltaic cell for converting light to electrical energy, said photovoltaic cell being disposed within said base member and being connected to said signal producing circuit to supply said electrical voltage thereto, said photovoltaic cell being positioned to receive light which is produced by said image display screen.

A method of processing control signals produced by an electrical circuit control device of the type in which manual movement of a first component to successive ones of a series of different settings causes a second component to output a circuit control signal that changes during the course of the movement to identify the successive settings of the first component, wherein irregularities of manufacture may cause the original values of the control signal produced at the successive settings to differ from desired values in an initially unknown manner, comprising the steps of:

• detecting and storing the initially unknown original value of said control signal at each of a series of the different settings of said first component,
• designating an assigned value for the control signal at each of said series of different settings of said first component which assigned values are the desired values of the control signal at the different settings,
• storing each assigned value in association with the corresponding original value,
• thereafter responding to movement of said first component to any particular one of said series of different settings thereof by converting the detected original value of said control signal at that setting to the associated assigned value.

A control device for an electrical circuit which control device has a base member and a turnable knob coupled thereto, the knob being turnable to any of a plurality of different angular orientations to change an electrical condition in the circuit, wherein the improvement comprises:

• said base member being affixed to an electronic image display device which has an image display area at which changeable images are displayed, said base member and knob being in front of said image display device and wherein at least a portion of said knob overlays the image display area of said image display device, wherein said knob turns about an axis of rotation that intersects said base member, further including at least one magnet and at least one Hall effect sensor secured to one of said knob and said base member, said magnet and Hall effect sensor being spaced apart in a radial direction relative to said axis of rotation of said knob, an annular body of ferromagnetic material secured to the other of said knob and said base member, said annular body of ferromagnetic material being centered on said axis of rotation and being positioned to extend within the magnetic field of said magnet, wherein the expanse of said body of ferromagnetic material in a direction parallel to said axis of rotation progressively changes at successive locations around the circumference of said body of ferromagnetic material.

A control device for an electrical circuit which control device has a base member and a turnable knob coupled thereto, the knob being turnable to any of a plurality of different angular orientations to change an electrical condition in the circuit, wherein the improvement comprises:

• said base member being affixed to an electronic image display device which has an image display area at which changeable images are displayed, said base member and knob being in front of said image display device and wherein at least a portion of said knob overlays the image display area of said image display device wherein said knob and base member form a circuit housing and wherein said image display device has a transparent cover plate at said image display area and wherein said base member of said control device extends into an opening in said transparent cover plate, further including a position signal producing circuit disposed within said circuit housing and which produces a signal which varies in response to turning of said knob, a light source producing a light beam which encodes said signal, said light source being secured to said base member in position to direct said light beam into said transparent cover plate along a light path which is within said transparent cover plate and which extends from said opening to a location at an edge of said transparent cover plate, a light detector disposed at a marginal region of said image display device and being positioned to view said location and to receive light which has traveled along said light path and which outputs said signal in electrical form.

A control device for an electrical circuit which control device has a base member and a turnable knob coupled thereto, the knob being turnable to any of a plurality of different angular orientations to change an electrical condition in the circuit, wherein the improvement comprises:

• said base member being affixed to an electronic image display device which has an image display area at which changeable images are displayed, said base member and knob being in front of said image display device and wherein at least a portion of said knob overlays the image display area of said image display device, further including a continuous annular band of electrically resistive material situated between said turnable knob and said image display device, a wiper contact secured to said turnable knob and wherein a portion of said wiper contact bears against said continuous annular band of electrically resistive material and wherein said portion of said wiper contact travels along said annular band of electrically resistive material in contact therewith as said knob is turned, an electrical voltage source having a positive terminal and a negative terminal, one of said terminals being electrically connected to said wiper contact and the other of said terminals being electrically connected to said annular band of electrically resistive material at a first fixed location thereon, a first analog to digital signal converter having an input connected to said annular band of electrically resistive material at a second fixed location thereon which second fixed location is spaced apart from said first fixed location, a second analog to digital signal converter having an input connected to said annular band of electrically resistive material at a third fixed location thereon which third fixed location is spaced apart from both of said first fixed location and said second fixed location, wherein said first and second analog to digital signal converters output a pair of location signals one of which has a value determined by the current voltage at said second fixed location and the other having a value determined by the current voltage at said third fixed location, and a digital data processor which repetitively receives the pairs of location signals and which stores a plurality of different output signal values each being associated with a different pair of location signal values and which outputs a control signal having the value that is associated with the current pair of location signal values.