Backlight current control in portable electronic devices

• US 20060087245A1
• Filed: 10/27/2004
• Published: 04/27/2006
• Est. Priority Date: 10/27/2004
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Allore, Joseph L., Ng, Richard, Cox, Daniel B.
• Granted Patent: US 7,808,185 B2
• Time in Patent Office: Days
• US Class Current: 315/149
• CPC Class Codes: G06F 1/1615 with several enclosures having relative motions, each enclosure supporting at least one I/O or computing function constructional details of portable telephones comprising a plurality of mechanically joined movable body parts H04M1/0206
• CPC Class Codes: G06F 1/1637 Details related to the display arrangement, including those related to the mounting of the display in the housing
• CPC Class Codes: G06F 1/1662 Details related to the integrated keyboard
• CPC Class Codes: G06F 1/1677 for detecting open or closed state or particular intermediate positions assumed by movable parts of the enclosure, e.g. detection of display lid position with respect to main body in a laptop, detection of opening of the cover of battery compartment
• CPC Class Codes: G06F 1/1684 Constructional details or arrangements related to integrated I/O peripherals not covered by groups G06F1/1635 - G06F1/1675
• CPC Class Codes: G06F 1/1686 the I/O peripheral being an integrated camera
• CPC Class Codes: H04M 1/22 Illumination; Arrangements for improving the visibility of characters on dials
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion

Abstract

A method in a portable electronic device (100) having a user interface illumination (110) is disclosed. The method comprises sensing (202) an ambient light level in a neighborhood of the portable electronic device with a sensor (104) of the portable electronic device. Based on the ambient light level sensed, then controlling (204) a visual characteristic of the user interface illumination, wherein the user interface illumination is operated at a brightness between a maximum brightness and a minimum brightness for at least one ambient light level detected.

Claims

1. A method in a portable electronic device having a user interface backlight, the method comprising:

detecting an ambient light level in a neighborhood of the portable electronic device with a sensor of the portable electronic device; and

controlling brightness of the user interface illumination based on the ambient light level detected,

wherein the user interface backlight is operated at a brightness between a maximum brightness and a minimum brightness for at least one ambient light level detected.

2. The method of claim 1,

activating the user interface illumination based upon an event other than the ambient light level detected,

controlling brightness of the user interface illumination when the user interface backlight is activated.

3. The method of claim 1,

detecting the ambient light level at discrete intervals of time,

detecting the ambient light level at a relatively high rate when the illumination is activated,

detecting the ambient light level at a relatively low rate when the illumination is not activated.

4. The method of claim 1, variably controlling current to the user interface illumination includes selecting a current level from a look-up table stored on the portable electronic device based upon the ambient light level detected.

5. The method of claim 1, variably controlling current to the user interface illumination using an equation that specifies current as a function of the ambient light level detected.

6. A portable electronic device comprising:

a controller;

a user interface backlight coupled to the controller;

a light sensor coupled to the controller; and

a current source coupled to the controller,

the controller controlling current to the user interface backlight based on ambient light detected by the light sensor,

whereby brightness of the user interface backlight varies with the ambient current to the user interface backlight.

7. The portable electronic device of claim 6,

the user interface backlight is one of a keypad backlight and a display backlight.

8. The portable electronic device of claim 6,

a second light sensor located at a position on the device other than the position of the first light sensor, the second light sensor coupled to the controller.

9. The portable electronic device of claim 8,

wherein the controller further comprises a comparison means to compare a first light sensor measurement with a second light sensor measurement.

10. A method in a portable electronic device having a user interface, the method comprising:

measuring an ambient light level with a light sensor carried on the portable electronic device in response to an event associated with the device;

determining a correlation between the ambient light level and the event; and

controlling the brightness of the user interface illumination in response to the determined correlation.

11. The method of claim 10, controlling the contrast of the user interface in response to the determined correlation.

12. The method of claim 10, activating an illumination source to illuminate the user interface prior to measuring the ambient light level.

13. The method of claim 10, activating an illumination source to illuminate the user interface after the step of measuring the ambient light level.

14. The method of claim 10, activating an illumination source to illuminate the user interface after the step of determining the correlation between the ambient light level and the event.

15. The method of claim 10, measuring the ambient light level with a camera carried on the device.

16. The method of claim 10, independently controlling the illumination level of a first user interface and independently controlling the illumination level of a second user interface in response to the measured ambient light level.

17. The method of claim 10,

after the step of measuring the ambient light level, activating a timer;

determining if the ambient light level reaches a first predetermined ambient light level which is sensed by the light sensor; and

deactivating the illumination of the user interface.

18. A method in an electronic device having user interface illumination for improving current drain comprising:

measuring an ambient light level with a light sensor carried on the portable electronic device in response to an event associated with the device;

determining a correlation between the ambient light level and the event; and

controlling a visual characteristic of the user interface in response to the determined correlation.

19. The method of claim 18,

controlling a contrast level of the user interface in response to the determined correlation.

20. The method of claims 18,

controlling at least one of a contrast level and a brightness level of the user interface in response to the determined correlation.