Automatic display unit activation

• US 8,174,483 B2
• Filed: 02/20/2008
• Issued: 05/08/2012
• Est. Priority Date: 02/20/2008
• Status: Active Grant

• Current Assignee: Computime Electronics Company Limited
• Original Assignee: Computime Electronics Company Limited
• Inventors: Cheng, Chung Ming, Chan, Ho Sin Vincent
• Primary Examiner(s): DINH, DUC Q
• Application Number:
  US12/034,391
• Publication Number:
  US 20090207122A1
• Time in Patent Office: 1,539 Days
• Field of Search: 345/211, 345/204, 345/690, 345/156, 345/169, 345/102, 345/87, 345/89
• US Class Current: 345/102
• 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 1/3265 Power saving in display device
• CPC Class Codes: G09G 2330/022 in absence of operation, e.g. no data being entered during a predetermined time
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

The present invention provides apparatuses and methods for controlling the brightness of a display unit based on detected movement of an external object such as a user. An apparatus includes a display, e.g., a color liquid crystal display (LCD) or organic light emitting diode (OLED). A proximity circuit generates a transmitted signal and a received signal. The received signal results from the transmitted signal being reflected by an external object. A control unit processes the received signal to determine a degree of motion of the external object. When the degree of motion is greater than a first predetermined threshold but not greater than a second predetermined threshold, the display is activated and operating at partial intensity. When the degree of motion is greater than the second predetermined threshold, the display is activated at full intensity. The degree of motion may be determined from the variation of the received signal.

Claims

1. An apparatus comprising:

a display unit configured to display information to a user and having a backlight to illuminate the display;

a proximity circuit configured to generate a transmitted signal and to receive a received signal that is indicative of a user'"'"'s proximity; and

a control unit coupled to the display and the proximity detector and configured to perform;

obtaining the received signal from the proximity detector;

analyzing the received signal to determine a current degree of motion of the user'"'"'s proximity;

when the current degree of motion is not greater than a first predetermined threshold and not greater than a second predetermined threshold for at least a first predetermined time duration, deactivating the display unit;

when the current degree of motion is greater than the first predetermined threshold and not greater than the second predetermined threshold and the display unit is not already activated, turning the display unit to a first intensity level;

when the current degree of motion is greater than the second predetermined threshold, turning the display unit on a second intensity level, wherein the first intensity level and the second intensity level are different; and

when the current degree of motion is greater than the first predetermined threshold and not greater than the second predetermined threshold for at least a second predetermined time duration and the display unit is already activated, turning the display unit to the second intensity level.

2. The apparatus of claim 1, wherein the control unit is further configured to perform:

when the display unit is at the first intensity level and when a subsequent degree of motion is greater than the second predetermined threshold, activating the display unit at the second intensity level.

3. The apparatus of claim 1, wherein the proximity circuit is configured to determine a variation of the received signal and to obtain the current degree of motion from the variation.

4. The apparatus of claim 1, wherein the control unit is further configured to perform:

when the current degree of motion is greater than a third predetermined threshold, turning the display unit on a third intensity level.

5. The apparatus of claim 1, wherein the proximity circuit comprises:

an infrared (IR) transmitter configured to send the transmitted signal; and

an infrared receiver configured to detect the received signal, wherein the received signal corresponds to the transmitted signal being reflected from an external object.

6. The apparatus of claim 5, wherein the infrared transmitter is configured to periodically send the transmitted signal.

7. The apparatus of claim 1, wherein the apparatus comprises a thermostat.

8. The apparatus of claim 1, wherein the display unit comprises a liquid crystal display (LCD).

9. The apparatus of claim 1, wherein the display unit comprises an organic light emitting diode (OLED) display.

10. The apparatus of claim 1, wherein the display unit comprises a light emitting diode (LED) display.

11. The apparatus of claim 1, wherein the display unit includes a backlight to illuminate the display unit.

12. The apparatus of claim 1, wherein the control unit is further configured to perform:

when a subsequent degree of motion is below a predetermined low level, deactivating the display unit.

21. The apparatus of claim 3, wherein the variation of the received signal is obtained from a variance of the received signal.

13. A method comprising:

displaying information to a user on a display unit;

transmitting a transmitted signal;

receiving a received signal that is indicative of proximity of the user, wherein the received signal corresponds to the transmitted signal being reflected from an external object;

analyzing the received signal to determine a current degree of motion of the user'"'"'s proximity;

when the current degree of motion is not greater than a first predetermined threshold and not greater than a second predetermined threshold for at least a first predetermined time duration, deactivating the display unit;

when the current degree of motion is greater than the first predetermined threshold and not greater than the second predetermined threshold and the display unit is not already activated, turning the display unit to a first intensity level;

when the current degree of motion is greater than the second predetermined threshold, turning the display unit on a second intensity level, wherein the first intensity level and the second intensity level are different; and

when the current degree of motion is greater than the first predetermined threshold and not greater than the second predetermined threshold for at least a second predetermined time duration and the display unit is already activated, turning the display unit to the second intensity level.

14. The method of claim 13, further comprising:

when the display unit is at the first intensity level and when a subsequent degree of motion is greater than the second predetermined threshold, activating the display unit at the second intensity level.

15. The method of claim 13, further comprising:

determining a variation of the received signal; and

obtaining the current degree of motion from the variation.

16. The method of claim 15, wherein the determining comprises:

obtaining an average signal strength of the received signal;

measuring a difference between a sampled signal strength of the received signal and the average signal strength;

squaring the difference; and

repeating the measuring and the squaring for each sample of a set of consecutive samples.

17. The method of claim 13, further comprising:

determining an applied power level applied to the display unit to provide a desired intensity level for the display unit.

18. The method of claim 13, further comprising:

when the current degree of motion is greater than a third predetermined threshold, turning the display unit on a third intensity level.

19. The method of claim 13, further comprising:

when a subsequent degree of motion is below a predetermined low level, deactivating the display unit.

20. The method of claim 13, further comprising:

when no key activity is detected for a predetermined time duration, deactivating the display unit.

22. The method of claim 15, wherein the variation of the received signal is obtained from a variance of the received signal.