Input device with capacitive antenna

• US 20020126094A1
• Filed: 04/17/2002
• Published: 09/12/2002
• Est. Priority Date: 01/12/2001
• Status: Abandoned Application

• Current Assignee: Logitech Europe S A (Logitech International SA)
• Original Assignee: Logitech Europe S A (Logitech International SA)
• Inventors: Kehlstadt, Florian Max, Junod, Philippe
• Application Number:
  US10/124,892
• Publication Number:
  US 20020126094A1
• Time in Patent Office: Days
• US Class Current: 345/163
• 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: G06F 3/03543 Mice or pucks G06F3/03541 takes precedence
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device
• CPC Class Codes: H03K 2217/960775 Emitter-receiver or "fringe" type detection, i.e. one or more field emitting electrodes and corresponding one or more receiving electrodes
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

An input device having a housing and electronic circuitry for detecting user inputs, and transmitting signals corresponding to those inputs to an electronic device, such as a computer. An antenna is provided for transmitting or receiving signals. A hand detection circuit is provided, which uses said antenna for detecting the proximity of a user'"'"'s hand to the housing and producing a hand detect signal in response. In one embodiment, the antenna is a capacitive antenna. A capacitor is switched in parallel with the antenna when it is used in antenna mode, so that the impact on the antenna signaling of the capacitance of a user'"'"'s hand is minimized. In one embodiment, a sleep mode is provided for the electronic circuitry to conserve power. The hand detect signal will awaken the input device from its sleep mode.

Claims

1. An input device comprising:

a housing;

user input electronic circuitry for detecting user inputs and transmitting signals corresponding to said inputs to an electronic device;

an antenna;

an antenna circuit coupled to said antenna for transmitting or receiving signals; and

a hand detection circuit coupled to said antenna for detecting the proximity of a user'"'"'s hand to said housing using said antenna and producing a hand detect signal.

2. The input device of claim 1 wherein said antenna is an inductive antenna.

3. The input device of claim 1 wherein said antenna is a capacitive antenna.

4. The input device of claim 3 further comprising:

a capacitor; and

a switch for coupling said capacitor in parallel with said capacitive antenna when said antenna is used for transmitting or receiving signals instead of being used for hand detection.

5. The input device of claim 4 wherein said capacitor has a value more than double the capacitance of a hand.

6. The input device of claim 4 wherein said capacitor has a value more than ten times the capacitance of a hand.

7. The input device of claim 4 wherein said capacitor has a value of at least 10 pico farads.

8. The input device of claim 1 further comprising:

a sleep-mode circuit, coupled to said user input electronic circuitry, for activating a reduced power operation of said user input electronic circuitry;

said sleep mode circuit being responsive to said hand detect signal to awaken said user input electronic circuitry from said reduced power operation.

9. The device of claim 1 wherein said input device is a pointing device and said electronic device is a computer.

10. The device of claim 1 wherein:

said antenna comprises first and second electrodes on said housing for capacitive connection with a user'"'"'s hand; and

said hand detection circuit comprises

a first circuit, coupled to said first electrode, for determining an amount of time for charging of a capacitance connected to said first circuit, and

a second circuit, coupled to said second electrode, for determining an amount of time for discharging of a capacitance connected to said second circuit.

11. The device of claim 10 wherein said first circuit comprises:

a comparator;

a controller coupled to an output of said comparator;

a voltage divider feedback circuit coupled between an output and a reference voltage input of said comparator;

a detection capacitor coupled between said first electrode and a signal input of said comparator; and

a switching circuit selectively coupling said signal input of said comparator to high and low voltage supplies.

12. The device of claim 1 wherein said input device is a mouse, and said user input electronic circuitry is an optical module for reflecting light off a surface and detecting movement of said mouse relative to said surface.

16. The method of claim 15 wherein said detecting the proximity of a user'"'"'s hand detects a change in capacitance due to said proximity of a user'"'"'s hand.

17. The method of claim 16 further comprising switching a capacitor in parallel with said antenna when said antenna is used for transmitting or receiving signals instead of being used for hand detection.

13. An input device comprising:

a housing;

user input electronic circuitry for detecting user inputs and transmitting signals corresponding to said inputs to an electronic device;

a capacitive antenna;

an antenna circuit coupled to said antenna for transmitting or receiving signals;

a hand detection circuit coupled to said antenna for detecting the proximity of a user'"'"'s hand to said housing using said antenna and producing a hand detect signal;

a capacitor; and

a switch for coupling said capacitor in parallel with said capacitive antenna when said antenna is used for transmitting or receiving signals instead of being used for hand detection.

14. An input device comprising:

a housing;

user input electronic circuitry for detecting user inputs and transmitting signals corresponding to said inputs to an electronic device;

a capacitive antenna;

an antenna circuit coupled to said antenna for transmitting or receiving signals;

a hand detection circuit coupled to said antenna for detecting the proximity of a user'"'"'s hand to said housing using said antenna and producing a hand detect signal;

a capacitor, said capacitor having a value of at least 10 pico farads;

a switch for coupling said capacitor in parallel with said capacitive antenna when said antenna is used for transmitting or receiving signals instead of being used for hand detection;

a sleep-mode circuit, coupled to said user input electronic circuitry, for activating a reduced power operation of said user input electronic circuitry; and

said sleep mode circuit being responsive to said hand detect signal to awaken said user input electronic circuitry from said reduced power operation.

15. A method for operating an input device comprising:

detecting user inputs and transmitting signals corresponding to said inputs to an electronic device external to said input device;

transmitting or receiving signals using an antenna; and

detecting the proximity of a user'"'"'s hand to said input device using said antenna and producing a hand detect signal.