Apparatus for dynamically varying the resolution of a tactile sensor array

• US 5,237,879 A
• Filed: 10/11/1991
• Issued: 08/24/1993
• Est. Priority Date: 10/11/1991
• Status: Expired due to Term

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Original Assignee: AT&T, Inc.
• Inventors: Speeter, Thomas H.
• Primary Examiner(s): Razavi, Michael T.
• Assistant Examiner(s): MAY, TIMOTHY
• Application Number:
  US07/775,881
• Time in Patent Office: 683 Days
• Field of Search: 73/DIG. 4, 73/862.046, 73/862.68, 73/865.7, 73/862.041, 73/862.042, 73/862.043, 73/862.044, 73/727, 340/712, 341/34, 178/18, 178/19, 901/33
• US Class Current: 73/862.041
• CPC Class Codes: G01D 5/14 influencing the magnitude of a current or voltage
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: H03K 17/9618 using a plurality of detectors, e.g. keyboard

Abstract

Methods and apparatus are provided for dynamically varying the resolution of a tactile sensor array. Sensing elements in the array are selectively coupled to reduce the resolution of the array, thereby permitting very fast sampling rates with low resolution, while retaining the ability to sample with higher resolution at lower sampling rates. Sensing elements may be coupled, for example, through the sensor array addressing circuitry. The present invention permits a single sensor array to be used for both low and high resolution applications, thereby eliminating the need to change sensors between applications or to maintain several sets of sensor arrays.

Claims

1. An apparatus for monitoring force applied to a surface and producing data in response to the monitored force, comprising:

a force sensor having a plurality of separately-accessible force sensing elements, each of said sensing elements producing a force data output when accessed;

means coupled to said sensor for separately accessing each of said sensing elements; and

means for selectively electrically coupling at least two of said sensing elements to vary the spatial resolution of the sensor so that a single data output is produced by said at least two sensing elements if force is applied to any of said at least two sensing elements.

2. The apparatus of claim 1 wherein the means for separately accessing comprises:

means for selectively applying a voltage to a first terminal of each of said sensing element; and

means for selectively grounding a second terminal of each of said sensing elements.

3. The apparatus of claim 1, wherein said sensor comprises an array of sensing elements.

4. The apparatus of claim 1, further comprising means for preventing electrical current from flowing through sensing elements which are not currently accessed by said means for separately accessing.

5. The apparatus of claim 4, wherein said means for preventing electrical current from flowing is coupled to said means for separately accessing.

6. The apparatus of claim 1, wherein the sensor comprises a piezoresistive sensor.

7. The apparatus of claim 1, wherein the sensor comprises a variable capacitance sensor.

8. The apparatus of claim 1, wherein the sensor comprises an anisotropic material disposed between conductive elements of the sensor.

9. A circuit for selectively varying the resolution of a force sensor array which includes a plurality of force sensing elements that are separately addressable by a row and a column address to produce a force data output when addressed, comprising:

means for selectively applying a voltage to a first terminal of at least two of said sensing elements;

means for selectively grounding a second terminal of at least two of said sensing elements; and

means for selectively electrically coupling at least two of said sensing elements so that a single data output is produced by said elements if a force is applied to any of said at least two sensing elements, thereby varying the spatial resolution of the sensor array.

10. The apparatus of claim 9, wherein said means for selectively electrically coupling causes the means for selectively applying a voltage to apply a voltage simultaneously to the first terminal of at least two sensing elements.

11. The apparatus of claim 9, wherein said means for selectively electrically coupling causes the means for selectively grounding to ground simultaneously the second terminal of at least two sensing elements.

12. The apparatus of claim 9, further comprising means for preventing electrical current from flowing through sensing elements not being accessed.