Apparatus and method providing transformation for human touch force measurements

• US 8,035,535 B2
• Filed: 11/21/2007
• Issued: 10/11/2011
• Est. Priority Date: 11/21/2007
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Nousiainen, Jari O.
• Primary Examiner(s): Nguyen; Khai M
• Application Number:
  US11/986,487
• Publication Number:
  US 20090127004A1
• Time in Patent Office: 1,420 Days
• Field of Search: 341 50- 51, 341/155
• US Class Current: 341/50
• CPC Class Codes: G06F 3/02 Input arrangements using manually operated switches, e.g. using keyboards or dials
• 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 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0414 using force sensing means to determine a position
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers

Abstract

An apparatus includes a force sensor configured to be activated by a user and a control unit connected to an output of the force sensor. The control unit is configurable to operate in response to receipt of an m-bit value representing a measurement from the force sensor to transform the m-bit value to an n-bit transformed value, where n<m, and where the transformed value encodes an identification of one of a plurality of force ranges and contains a force measurement value within the identified one of the plurality of force ranges.

Claims

1. A method, comprising:

providing an m-bit value representing a measurement from a force sensor activated by a user of a device; and

transforming the m-bit value to an n-bit transformed value, where n<

m, and where the transformed value encodes an identification of one of a plurality of force ranges and contains a force measurement value within the identified one of the plurality of force ranges.

2. The method of claim 1, where the identification is encoded using a bits, and where the force measurement value is contained in n-a bits.

3. The method of claim 1, where the identification is encoded using a most significant bits of the transformed value, and where the force measurement value is contained in n-a least significant bits of the transformed value.

4. The method of claim 2, where in at least one force range corresponding to a least amount of force the n-a bits represent n-a least significant bits of the m-bit value, and in at least one force range corresponding to a greater amount of force the n-a bits represent n-a bits of the m-bit value that are intermediate to a least significant bit and to a most significant bit of the m-bit value.

5. The method of claim 4, where for a plurality of force ranges corresponding to increasing amounts of force a number of bits that are intermediate to the n-a bits of the m-bit value and the least significant bit of the m-bit value increases, resulting in one or more least significant bits of the m-bit value not being represented in the n-bit value.

6. The method of claim 1, where transforming further comprises removing noise from the transformed value.

7. The method of claim 1, where n=8.

8. The method of claim 1, where transforming results in changing a substantially logarithmic input force curve to a non-logarithmic force curve.

9. The method of claim 1, where transforming results in changing a substantially logarithmic input force curve to one of a substantially linear or a substantially quadratic force curve.

10. A computer-readable memory medium storing computer program instructions the execution of which results in operations that comprise:

inputting an m-bit value representing a measurement from a force sensor activated by a user of a device; and

transforming the m-bit value to an n-bit transformed value, where n<

m, and where the transformed value encodes an identification of one of a plurality of force ranges and contains a force measurement value within the identified one of the plurality of force ranges.

11. The memory medium of claim 10, where the identification is encoded using a bits, and where the force measurement value is contained in n-a bits.

12. The memory medium of claim 10, where the identification is encoded using a most significant bits of the transformed value, and where the force measurement value is contained in n-a least significant bits of the transformed value.

13. The memory medium of claim 11, where in at least one force range corresponding to a least amount of force the n-a bits represent n-a least significant bits of the m-bit value, and in at least one force range corresponding to a greater amount of force the n-a bits represent n-a bits of the m-bit value that are intermediate to a least significant bit and to a most significant bit of the m-bit value.

14. The memory medium of claim 13, where for a plurality of force ranges corresponding to increasing amounts of force a number of bits that are intermediate to the n-a bits of the m-bit value and the least significant bit of the m-bit value increases, resulting in one or more least significant bits of the m-bit value not being represented in the n-bit value.

15. The memory medium of claim 10, where the transforming operation further comprises removing noise from the transformed value.

16. The memory medium of claim 10, where n=8.

17. The memory medium of claim 10, where the transforming operation results in changing a substantially logarithmic input force curve to a non-logarithmic force curve.

18. An apparatus, comprising:

a force sensor configured to be activated by a user; and

a control unit connected to an output of the force sensor, said control unit configurable to operate in response to receipt of an m-bit value representing a measurement from the force sensor to transform the m-bit value to an n-bit transformed value, where n<

m, and where the transformed value encodes an identification of one of a plurality of force ranges and contains a force measurement value within the identified one of the plurality of force ranges.

19. The apparatus of claim 18, where the identification is encoded using a most significant bits of the transformed value, and where the force measurement value is contained in n-a least significant bits of the transformed value, where in at least one force range corresponding to a least amount of force the n-a bits represent n-a least significant bits of the m-bit value, and in at least one force range corresponding to a greater amount of force the n-a bits represent n-a bits of the m-bit value that are intermediate to a least significant bit and to a most significant bit of the m-bit value.

20. The apparatus of claim 19, where for a plurality of force ranges corresponding to increasing amounts of force a number of bits that are intermediate to the n-a bits of the m-bit value and the least significant bit of the m-bit value increases, resulting in one or more least significant bits of the m-bit value not being represented in the n-bit value.

21. The apparatus of claim 18, where said control unit, when transforming the m-bit value, removes noise from the transformed value.

22. The apparatus of claim 18, where n=8.

23. The apparatus of claim 18, where said control unit, when transforming the m-bit value, changes a substantially logarithmic input force curve to a non-logarithmic force curve.

24. An apparatus, comprising:

means for providing an m-bit value representing a measurement from a force sensor activated by a user; and

means for transforming the m-bit value to an n-bit transformed value, where n<

m, and where the transformed value encodes an identification of one of a plurality of force ranges and contains a force measurement value within the identified one of the plurality of force ranges, where the identification is encoded using a most significant bits of the transformed value, and where the force measurement value is contained in n-a least significant bits of the transformed value.

25. The apparatus of claim 24, where in at least one force range corresponding to a least amount of force the n-a bits represent n-a least significant bits of the m-bit value, and in at least one force range corresponding to a greater amount of force the n-a bits represent n-a bits of the m-bit value that are intermediate to a least significant bit and to a most significant bit of the m-bit value, and where for a plurality of force ranges corresponding to increasing amounts of force a number of bits that are intermediate to the n-a bits of the m-bit value and the least significant bit of the m-bit value increases, resulting in one or more least significant bits of the m-bit value not being represented in the n-bit value and thereby effectively filtering noise from the transformed value.