MULTIPLE ORIENTATION MOBILE ELECTRONIC HANDHELD DEVICE AND METHOD OF AMBIENT LIGHT SENSING AND BACKLIGHT ADJUSTMENT IMPLEMENTED THEREIN

• US 20110102451A1
• Filed: 11/05/2009
• Published: 05/05/2011
• Est. Priority Date: 11/05/2009
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Crugnale, Thomas James, Fletcher, Bergen Albert, Robinson, James Alexander, BROGA, Antanas Matthew
• Granted Patent: US 8,508,465 B2
• Time in Patent Office: Days
• US Class Current: 345/589
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2340/0492 Change of orientation of the displayed image, e.g. upside-down, mirrored
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

A method is set forth for automatically adjusting display brightness on a mobile electronic device having a light sensor, display screen and orientation sensor, for legibility under varying lighting conditions and orientations of the device. The method includes obtaining light level samples from the light sensor, and orientation from the orientation sensor, and adjusting backlight intensity of the display responsive to the light level samples and orientation of the device. Preferably, backlight adjustments are made from dim to bright notwithstanding orientation of the device whereas adjustments from bright to dim are made only for orientations of the device where the light sensor is unlikely to be covered.

Claims

1. A method for automatically adjusting backlight brightness on a mobile electronic device capable of operating in a DIM mode, an OFFICE mode and a BRIGHT mode, said device having a light sensor, an orientation sensor and a display, the method comprising:

obtaining light level samples from said light sensor;

determining orientation of said device; and

in the event said backlight brightness is in one of either OFFICE mode or BRIGHT mode, and the median value of said samples is less than a first threshold value and said device is in a first orientation, then adjusting the backlight intensity of said display to said DIM mode,

in the event said backlight brightness is in one of either OFFICE mode or BRIGHT mode, and the median value of said samples is less than a first threshold value and said device is in another orientation then continuing operation in said OFFICE mode;

in the event said backlight brightness is in DIM mode and the median value of said samples is greater than a second threshold value then adjusting the backlight intensity of said display to said OFFICE mode;

in the event said backlight brightness is in BRIGHT mode and the median value of said samples is greater than said first threshold value and less than a third threshold value, then adjusting the backlight intensity of said display to said OFFICE mode;

and

in the event said backlight brightness is in one of either said DIM mode or said OFFICE mode and the median value of said samples is greater than a fourth threshold value, then adjusting the backlight intensity of said display to said BRIGHT mode.

2. The method of claim 1, wherein said first orientation and said another orientation are orientations of said device for display in a portrait mode and a landscape mode, respectively.

3. The method of claim 1, wherein said first threshold value is approximately 16 Lux.

4. The method of claim 1, wherein said fourth threshold value is approximately 4400 Lux.

5. The method of claim 1, wherein said second threshold value is approximately 60 Lux.

6. The method of claim 1, wherein said third threshold value is approximately 3000 Lux.

7. The method of claim 1, wherein said light level samples are obtained at a first sampling rate upon activation of said light sensor or in the event of a transition from said DIM mode to said OFFICE or BRIGHT modes or from said OFFICE mode to said BRIGHT mode, and otherwise are obtained at a second sampling rate.

8. The method of claim 7, wherein said median value is calculated from five consecutive ones of said light level samples.

9. The method of claim 8, wherein said first sampling rate is maintained for five samples whereupon further light level samples are obtained at said second sampling rate.

10. The method of claim 9, wherein said first sampling rate is one sample per approximately 400 ms and said second sampling rate is one sample per approximately 1.2 ms.

11. The method of claim 10, wherein said first and second sampling rates are each subject to a variance of approximately +/−

12.5%.

12. The method of claim 8, wherein said median value is calculated by sorting and selecting the third of said five samples.

13. A mobile electronic device, comprising:

a light sensor;

an orientation sensor;

a display; and

a processor connected to said light sensor, said display and said orientation sensor for

obtaining light level samples from said light sensor;

determining orientation of said device from said orientation sensor; and

in the event said backlight brightness is in one of either OFFICE mode or BRIGHT mode, and the median value of said samples is less than a first threshold value and said device is in a first orientation, then adjusting the backlight intensity of said display to said DIM mode,

in the event said backlight brightness is in one of either OFFICE mode or BRIGHT mode, and the median value of said samples is less than a first threshold value and said device is in another orientation then continuing operation in said OFFICE mode;

in the event said backlight brightness is in DIM mode and the median value of said samples is greater than a second threshold value then adjusting the backlight intensity of said display to said OFFICE mode;

in the event said backlight brightness is in BRIGHT mode and the median value of said samples is greater than said first threshold value and less than a third threshold value, then adjusting the backlight intensity of said display to said OFFICE mode;

and

in the event said backlight brightness is in one of either said DIM mode or said OFFICE mode and the median value of said samples is greater than a fourth threshold value, then adjusting the backlight intensity of said display to said BRIGHT mode.

14. The mobile electronic device claim 13, wherein said orientation device comprises an accelerometer for detecting orientation of said device in at least said first orientation and said another orientation.

15. The mobile electronic device claim 13, wherein said display is an LCD display.