Force and torque converter with improved digital optical sensing circuitry

• US 5,798,748 A
• Filed: 06/07/1995
• Issued: 08/25/1998
• Est. Priority Date: 06/07/1995
• Status: Expired due to Fees

• Current Assignee: Labtec, Inc. (Logitech International SA)
• Original Assignee: Spacetec IMC Corporation
• Inventors: Avery, Hal, Hilton, John, Roundtree, Stephan
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): WU, XU MING
• Application Number:
  US08/481,650
• Time in Patent Office: 1,175 Days
• Field of Search: 345/156, 345/157, 345/162, 345/163, 345/165, 345/166
• US Class Current: 345/156
• CPC Class Codes: G01D 18/008 with calibration coefficients stored in memory
• CPC Class Codes: G01L 5/166 using photoelectric means
• CPC Class Codes: G06F 3/0312 for tracking the rotation of a spherical or circular member, e.g. optical rotary encoders used in mice or trackballs using a tracking ball or in mouse scroll wheels tracking relative movement in co-operation with a regularly or irregularly patterned surface, e.g. as in optical mice G06F3/0317; constructional details of scroll or thumb-wheels G06F3/0362; optical rotary encoders G01D5/3473
• CPC Class Codes: G06F 3/033 Pointing devices displaced or positioned by the user , e.g. mice, trackballs, pens or joysticks; Accessories therefor digitisers characterised by the transducing means G06F3/041
• CPC Class Codes: G06F 3/0338 with detection of limited linear or angular displacement of an operating part of the device from a neutral position, e.g. isotonic or isometric joysticks

Abstract

An apparatus provides an electronic signal in response to at least one of an applied force and an applied torque. The apparatus includes a detection device that detects movement of a movable member relative to a base, and provides the electronic signal, by driving a plurality of first sensor components. The detection device includes a control circuit having a first output that provides a digital control signal, and a first input for receiving a comparison signal, and a second output that provides the detection signal according to the comparison signal; a digital-to-analog converter having an input coupled to the first output of the control circuit, and an output that provides the drive signal in response to the digital control signal; and a measuring circuit having a first input coupled to the output of the digital-to-analog converter, a second input that receives a result signal from a plurality of second sensor components co-acting with the plurality of first sensor components, and an output coupled to the first input of the control circuit that provides the comparison signal, the plurality of first sensor components and the plurality of second sensor components co-acting with the controlling mechanism. The detection device is constructed using a method of constructing a printed circuit board assembly which includes the steps of: (A) forming a series of grooves in first PCB material to produce a bending region thereon; (B) bonding second PCB material to the first PCB material to produce a intermediate assembly, the second PCB material having an electrically conductive layer on one side; and (C) bending the intermediate assembly into the printed circuit board assembly.

Claims

1. A device for providing a detection signal in response to a drive signal for driving a plurality of first sensor components, the device comprising:

a control circuit having a first output that provides a digital control signal, a first input for receiving a comparison signal, and a second output that provides the detection signal according to the comparison signal;

a digital-to-analog converter having an input coupled to the first output of the control circuit, and an output that provides the drive signal in response to the digital control signal; and

a measuring circuit having a first input coupled to the output of the digital-to-analog converter, a second input that receives a result signal from a plurality of second sensor components co-acting with the plurality of first sensor components, and an output coupled to the first input of the control circuit that provides the comparison signal, wherein the digital control signal provided by the control circuit has a first drive value during a first time interval to drive the plurality of first sensor components, and a plurality of comparison values during a second time interval to measure a result value of the result signal.

2. The device of claim 1, wherein the measuring circuit includes:

a sample-and-hold circuit having an input coupled to the second input of the measuring circuit that receives the result signal, and an output that provides a temporarily stored signal indicative of the result signal; and

a comparator having a first input coupled to the first input of the measuring circuit, a second input coupled to the output of the sample-and-hold circuit that receives the temporarily stored signal, and an output coupled to the output of the measuring circuit.

3. The device of claim 2, wherein the control circuit further includes a third output, and wherein the measuring circuit further includes:

a multiplexor interconnected between the second input of the measuring circuit and the input of the sample-and-hold circuit, the multiplexor having a first input coupled to the third output of the control circuit, a second input coupled to the second input of the measuring circuit, and an output coupled to the input of the sample-and-hold circuit.

4. The device of claim 1, wherein the control circuit further includes a fourth output, and the device further includes:

a drive selection circuit having a first input coupled to the fourth output of the control circuit, a second input coupled to the output of the digital-to-analog converter, and an output that selects one of the plurality of first sensor components and applies the drive signal to the selected one of the plurality of first sensor components.

5. The device of claim 4, wherein the control circuit further includes a second input, and the device further includes:

a memory coupled to the second input of the control circuit, for storing a plurality of calibration values, each calibration value defining a drive value of the digital control signal for each of the plurality of first sensor components, wherein the first drive value is defined by one of the plurality of calibration values.

6. The device of claim 1, wherein the control circuit, the digital-to-analog converter, and the measuring circuit are integrated within a semiconductor component.

7. The device of claim 6, further including:

an interface circuit coupled to the second output of the control circuit, for providing the detection signal to an external device.

8. The device of claim 1, wherein each of the plurality of first sensor components corresponds to one of the plurality of second sensor components to form a plurality of sensor sets, and wherein the first drive value is one of a plurality of drive values that control the drive signal so that each sensor set provides a similar response.

9. The device of claim 8, wherein the control circuit is arranged to alternate the digital control signal between the plurality of comparison values and one of the plurality of drive values in a time multiplexed manner.

10. The device of claim 1, further comprising the plurality of first sensor components, and the plurality of second sensor components, one of the plurality of first sensor components being driven by the drive signal when the digital control signal has the first drive value during the first time interval.

11. A device for providing a detection signal in response to a drive signal for driving a plurality of first sensor components, the device comprising:

a control circuit having a first output that provides a digital control signal, a first input for receiving a comparison signal, and a second output that provides the detection signal according to the comparison signal;

a digital-to-analog converter having an input coupled to the first output of the control circuit, and an output that provides the drive signal in response to the digital control signal; and

means, coupled to the first input of the control circuit, for providing the comparison signal according to a comparison of the analog signal of the digital-to-analog converter and a result signal from a plurality of second sensor components co-acting with the plurality of first sensor components, wherein the digital control signal provided by the control circuit has a first drive value during a first time interval to drive the plurality of first sensor components, and a plurality of comparison values during a second time interval to measure a result value of the result signal.

12. The device of claim 11, wherein the control circuit further includes a third output, and the means for providing includes:

means, coupled to the third output of the control circuit, for isolating at least one of the plurality of second sensor components to reduce a settling time of the result signal.

13. The device of claim 11, wherein the control circuit further includes a second input, and the device further includes:

a memory coupled to the second input of the control circuit, for storing a plurality of calibration values, each calibration value defining a drive value of the digital control signal for each of the plurality of first sensor components, wherein the first drive value is defined by one of the plurality of calibrated values.

14. The device of claim 11, wherein each of the plurality of first sensor components corresponds to one of the plurality of second sensor components to form a plurality of sensor sets, and wherein the first drive value is one of a plurality of drive values that control the drive signal so that each sensor set provides a similar response.

15. The device of claim 14, wherein the control circuit is arranged to alternate the digital control signal between the plurality of comparison values and one of the plurality of drive values in a time multiplexed manner.

16. The device of claim 11, further comprising the plurality of first sensor components, and the plurality of second sensor components, one of the plurality of first sensor components being driven by the drive signal when the digital control signal has the first drive value during the first time interval.

17. An apparatus for providing an electronic signal in response to at least one of an applied force and an applied torque, the apparatus comprising:

a base;

a movable member that provides movement relative to the base in response to the at least one of an applied force and an applied torque;

a controlling mechanism connected to the base and co-acting with the movable member to control the movement of the movable member relative to the base; and

a detection device that detects the movement of the movable member relative to the base, and provides the electronic signal, by driving a plurality of first sensor components, the detection device including;

a control circuit having a first output that provides a digital control signal, a first input for receiving a comparison signal, and a second output that provides a detection signal, as the electronic signal, according to the comparison signal,

a digital-to-analog converter having an input coupled to the first output of the control circuit, and an output that provides the drive signal in response to the digital control signal, and

a measuring circuit having a first input coupled to the output of the digital-to-analog converter, a second input that receives a result signal from a plurality of second sensor components co-acting with the plurality of first sensor components, and an output coupled to the first input of the control circuit that provides the comparison signal, the plurality of first sensor components and the plurality of second sensor components co-acting with the controlling mechanism, wherein the digital control signal provided by the control circuit has a first drive value during a first time interval to drive the plurality of first sensor components, and a plurality of comparison values during a second time interval to measure a result value of the result signal.

18. The apparatus of claim 17, wherein controlling mechanism includes a plurality of resilient mechanisms, and wherein at least a portion of the detection circuit includes:

a plurality of rigid members, each rigid member supporting at least one of the plurality of first sensor components and the plurality of second sensor components, the plurality of rigid members and the plurality of resilient members being disposed around the base so that the at least one sensor component supported by each rigid member is aligned in a predetermined orientation relative to one of the plurality of resilient mechanisms of the controlling mechanism.

19. The apparatus of claim 17, wherein each of the plurality of first sensor components corresponds to one of the plurality of second sensor components to form a plurality of sensor sets, and wherein the first drive value is one of a plurality of drive values that control the drive signal so that each sensor set provides a similar response.

20. The apparatus of claim 19, wherein the control circuit is arranged to alternate the digital control signal between the plurality of comparison values and one of the plurality of drive values in a time multiplexed manner.

21. The apparatus of claim 17, further comprising the plurality of first sensor components, and the plurality of second sensor components, one of the plurality of first sensor components being driven by the drive signal when the digital control signal has the first drive value during the first time interval.