Untethered stylus empolying multiple reference frequency communication

• US 8,040,330 B2
• Filed: 12/28/2006
• Issued: 10/18/2011
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Hauck, Karl P.
• Primary Examiner(s): Lao; Lun-Yi
• Assistant Examiner(s): Suteerawongsa; Jarurat
• Application Number:
  US11/617,312
• Publication Number:
  US 20080156546A1
• Time in Patent Office: 1,755 Days
• Field of Search: 345/179, 178/19.01
• US Class Current: 345/179
• CPC Class Codes: G06F 3/03545 Pens or stylus

Abstract

An untethered stylus is configured to cooperate with a location sensing device that generates a drive signal. The stylus includes transceiver circuitry disposed in a housing, which is configured to receive the drive signal and transmit a stylus signal for reception by the location sensor. Energy circuitry is disposed in the housing and energized by the drive signal. A reference frequency generator, disposed in the housing and coupled to the transceiver circuitry and energy circuitry, is configured to generate a number of reference frequencies based on a source frequency of the drive signal, the reference frequencies indicative of a number of stylus states and synchronized to the source frequency of the drive signal. The transceiver circuitry is configured to mix the reference frequencies with the stylus signal.

Claims

1. An untethered stylus configured to cooperate with a location sensor, the location sensor configured to generate a drive signal, the stylus comprising:

a housing;

transceiver circuitry disposed in the housing, the transceiver circuitry configured to receive the drive signal and transmit a stylus signal for reception by the location sensor;

energy circuitry disposed in the housing and energized by the drive signal; and

a reference frequency generator disposed in the housing and coupled to the transceiver circuitry and energy circuitry, the reference frequency generator configured to generate a plurality of reference frequencies based on a source frequency of the drive signal, the plurality of reference frequencies indicative of a plurality of stylus states and synchronized to the source frequency of the drive signal, wherein the transceiver circuitry is configured to mix all of the plurality of reference frequencies with the stylus signal at a same point in time.

2. The stylus of claim 1, further comprising switch circuitry supported by the housing and coupled to the reference frequency generator, the switch circuitry comprising one or more switches actuatable by a user of the stylus, at least some of the plurality of reference frequencies indicative of a state of the one or more switches.

3. The stylus of claim 2, wherein the one or more switches correspond to one or more user-initiateable functions.

4. The stylus of claim 2, wherein the one or more switches correspond to one or more mouse functions.

5. The stylus of claim 1, wherein the transceiver circuitry is configured to modulate the stylus signal with the plurality of reference frequencies.

6. The stylus of claim 1, wherein the source frequency of the drive signal is a multiple of each of the plurality of reference frequencies.

7. The stylus of claim 1, wherein each of the plurality of reference frequencies corresponds to a multiple of the source frequency of the drive signal.

8. The stylus of claim 1, wherein the reference frequency generator comprises a frequency divider.

9. The stylus of claim 1, wherein the reference frequency generator comprises a digital divider.

10. The stylus of claim 1, wherein the reference frequency generator comprises a frequency multiplier.

11. The stylus of claim 1, wherein the reference frequency generator comprises a frequency multiplier and a frequency divider.

12. A method implemented in an untethered stylus for use with a location sensor, comprising:

receiving a drive signal by the stylus transmitted from the location sensor;

energizing the stylus in response to receiving the drive signal;

generating at the stylus a plurality of reference frequencies based on a source frequency of the drive signal, the plurality of reference frequencies indicative of a plurality of stylus states and synchronized to the source frequency of the drive signal; and

mixing all of the plurality of reference frequencies with the stylus signal at a same point in time for reception by the location sensor.

13. The method of claim 12, comprising generating one or more switch signals each indicative of a state of one or more user-actuatable switches of the stylus, at least some of the plurality of reference frequencies indicative of the one or more switch signals.

14. The method of claim 13, wherein the one or more switch signals correspond to one or more user-initiateable functions.

15. The method of claim 13, wherein the one or more switch signals correspond to one or more mouse functions.

16. The method of claim 12, comprising modulating the stylus signal with the plurality of reference frequencies.

17. The method of claim 12, wherein the source frequency of the drive signal is a multiple of each of the plurality of reference frequencies.

18. The method of claim 12, wherein each of the plurality of reference frequencies corresponds to a multiple of the source frequency of the drive signal.

19. The method of claim 12, wherein at least some of the plurality of reference frequencies corresponds to non-integer frequencies based on the source frequency of the drive signal.

20. An apparatus implemented in an untethered stylus for use with a location sensor, comprising:

a receiver configured to receive a drive signal at the stylus transmitted from the location sensor;

a power circuit provided at the stylus and energized in response to receiving the drive signal;

means, coupled to the receiver and power circuit, for generating at the stylus a plurality of reference frequencies based on a source frequency of the drive signal, the plurality of reference frequencies indicative of a plurality of stylus states and synchronized to the source frequency of the drive signal; and

a transmitter coupled to the generating means and configured to mix all of the plurality of reference frequencies with the stylus signal at a same point in time.

21. The apparatus of claim 20, further comprising switch circuitry coupled to the generating means, the switch circuitry comprising one or more switches actuatable by a user of the stylus, at least some of the plurality of reference frequencies indicative of a state of the one or more switches.