Touch wake for electronic devices

• US 20060294523A1
• Filed: 06/23/2005
• Published: 12/28/2006
• Est. Priority Date: 06/23/2005
• Status: Active Grant

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Beard, Paul, Woodings, Ryan Winfield
• Granted Patent: US 8,089,461 B2
• Time in Patent Office: Days
• US Class Current: 718/104
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3231 Monitoring the presence, absence or movement of users
• CPC Class Codes: G06F 1/3259 Power saving in cursor control device, e.g. mouse, joystick, trackball
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A system to generate a wakeup signal for a low power device: The system includes a capacitor, the capacitance of which changes when a user touches the device by placing a finger or hand near a certain location on the device. The capacitor is cyclically charged to a pre-established value and then discharged. The time required to charge and discharge the capacitor is a function of the capacitor size and thus, a function of whether or not the operator is touching the device. The number of charge-discharge cycles that occur in a certain period of time is counted. If the number is relatively small, it indicated that a user is touching the device and a wake signal is generated. If the number is relatively large, it means that the user is not touching the device and no wake signal is generated. Thus, in the embodiments shown, a wake signal is generated when the operator touches the device.

Claims

1. ) A wakeup system for generating a signal to wake a device from a sleep state when an operator touches said device, said system comprising:

a conductive strip that is positioned in an area of said device touched by an operator using said device,

a voltage source

a connection to said conductive strip, said strip forming a capacitor, the capacitance of which is increased when a user touches said device,

a switch having two positions, one of which connects said capacitor to said voltage source and the second of which connects said capacitor to ground, whereby said capacitor is alternately charged and discharged,

a detector for determining when said capacitor reaches a pre-set charge and when said capacitor is fully discharged,

a control circuit responsive to said detector for cyclically changing the position of said switch, a change being made whenever when said capacitor reaches said pre-set charge and when said capacitor is fully discharged,

a counter for counting the number of cycles of said switch in a pre-established period of time,

a circuit for generating said wake signal if said number of cycles is below a pre-established number during said pre-established period of time.

2. ) The wakeup system recited in claim 1, wherein said device is battery operated.

3. ) The wakeup system recited in claim 1 wherein said device is a battery-operated mouse.

4. ) The wakeup system recited in claim 1 wherein said device is a mouse having a casing and said conductive strip is positioned inside said casing.

5. ) The wakeup system recited in claim 4 wherein said casing is made of plastic.

6. ) The wakeup system recited in claim 1 wherein said device is a computer mouse and said conductive strip is located on the side of said mouse.

7. ) The wakeup system recited in claim 1 including a plurality of conductive strips forming said capacitor.

8. ) The wakeup system recited in claim 1 wherein said preset charge is a charge that generates a voltage of three volts.

9. ) The wakeup system recited in claim 1 wherein said control circuit includes a clock, a counter and a state machine.

10. ) The wakeup system recited in claim 1 wherein said device comprises a computer mouse that has a casing make of plastic and wherein said conductive strip is located on the inside of said casing.

13. ) The wakeup method recited in claim 1 wherein said device is a battery-operated mouse.

14. ) The wakeup method recited in claim 1 wherein said device is a mouse having a casing and said conductive strip is positioned inside said casing.

15. ) The wakeup method recited in claim 14 wherein said casing is made of plastic.

11. ) A method of generating a wakeup signal for a low power device comprising the steps of:

changing the value of capacitance of a capacitor from a relatively low value to a relatively high value when an operator touches said device,

periodically measuring the value of said capacitor,

generating a wakeup signal if for said device if said capacitor has a relatively high value.

12. ) The wakeup method recited in claim 11, wherein said device is a battery operated wireless computer mouse, which goes into a sleep state when not moved for a particular period of time.

16. ) The wakeup method recited in claim 12 wherein said computer mouse has a non-conducting casing, and said capacitor is formed by a conductive strip located on the inside of said casing.

17. ) The wakeup method recited in claim 11 wherein said device includes a plurality of conductive strips forming said capacitor.

18. ) The wakeup method recited in claim 11 wherein said device comprises a computer mouse that has a casing make of plastic and wherein said capacitor comprises a conductive strip located on the inside of said casing.

19. ) A wakeup system for generating a signal to wake a device from a sleep state when an operator touches said device, said system comprising:

conductive means forming a capacitor, said conductive means being positioned so that the capacitance of said conductive means is increased from a relatively low value to a relatively high value when an operator touches said device,

measuring means for determining the value of said capacitor,

circuit means responsive to said measuring means for generating said wake signal if said capacitor has a relatively high value.

20. ) The wakeup system recited in claim 19 wherein said device is a battery operated wireless mouse having a casing and said conductive means is positioned inside said casing means at a position on said casing where an operator naturally touches said mouse when using said mouse