Automatic screen and keypad brightness adjustment on a mobile handheld electronic device

• US 20070097065A1
• Filed: 10/31/2005
• Published: 05/03/2007
• Est. Priority Date: 10/31/2005
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Mailloux, Jerry, Kreek, Conrad, Bocking, Andrew, Lowles, Robert, Wu, Ken, Robinson, James, Winter, Bruce, Hashi, Ahmed, Brubacher-Cressman, Dale
• Granted Patent: US 7,701,434 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• 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 1/1684 Constructional details or arrangements related to integrated I/O peripherals not covered by groups G06F1/1635 - G06F1/1675
• CPC Class Codes: G06F 3/0202 Constructional details or processes of manufacture of the input device
• CPC Class Codes: G06F 3/04897 Special input arrangements or commands for improving display capability
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0653 Controlling or limiting the speed of brightness adjustment of the illumination source
• CPC Class Codes: G09G 2330/022 in absence of operation, e.g. no data being entered during a predetermined time
• 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: H01H 2219/038 ambient light dependent

Abstract

A method is set forth for automatically adjusting screen and keypad brightness on a mobile electronic device having a light sensor, display screen and keypad, for optimum legibility under varying lighting conditions, with minimal eye strain and distraction to the user. The method includes obtaining light level samples from the light sensor, and independently adjusting backlight intensity of the display screen and keypad responsive to the light level samples. Preferably, correct screen and keypad adjustments are made responsive to the user pulling his or her handheld device out of its holster notwithstanding non-optimal ambient light detection while the device is being removed from the holster. According to another aspect, the described method allows for ambient light detection in a handheld device where the light sensor and a message notification indicator share a common light pipe.

Claims

1. A method for automatically adjusting screen and keypad brightness on a mobile electronic device having a light sensor, display screen and keypad, comprising:

obtaining light level samples from said light sensor; and

independently adjusting backlight intensity of said display screen and keypad responsive to said light level samples, wherein adjusting the backlight intensity of said display screen further includes comparing a median value of said samples to respective threshold values corresponding to DIM, OFFICE and BRIGHT modes of backlight intensity, wherein said backlight intensity is adjusted from DIM mode to OFFICE mode in the event said median value of said samples is greater than approximately 70 Lux, wherein said backlight intensity is adjusted from DIM mode to BRIGHT mode in the event said median value of said samples is greater than approximately 4400 Lux, wherein said backlight intensity is adjusted from OFFICE mode to DIM mode in the event said median value of said samples is less than approximately 16 Lux, wherein said backlight intensity is adjusted from OFFICE mode to BRIGHT mode in the event said median value of said samples is greater than approximately 4400 Lux, wherein said backlight intensity is adjusted from BRIGHT mode to DIM mode in the event said median value of said samples is less than approximately 16 Lux, and wherein said backlight intensity is adjusted from BRIGHT mode to OFFICE mode in the event said median value of said samples is less than approximately 3000 Lux.

2. The method of claim 1, wherein the backlight intensity of said keypad is adjusted from an OFF mode to an ON mode in the event a current light level sample is less than a first threshold value and from an ON mode to an OFF mode in the event said current light level sample is greater than a second threshold value for a predetermined time period.

3. The method of claim 2, wherein said first threshold value is approximately 60 Lux.

4. The method of claim 3, wherein said second threshold value is approximately 250 Lux and said predetermined time period is approximately 30 seconds.

5. 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 a second sampling rate.

6. The method of claim 5, wherein said median value is calculated from five consecutive ones of said light level samples.

7. The method of claim 6, wherein said-first sampling rate is maintained for five samples whereupon further light level samples are obtained at said second sampling rate.

8. The method of claim 7, 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.

9. The method of claim 8, wherein said first and second sampling rates are each subject to a variance of approximately ±

12.5%.

10. The method of claim 6, wherein said median value is calculated by sorting and selecting the third of said five samples.

11. The method of claim 2, wherein the backlight intensity of said keypad is adjusted from an ON mode to OFF mode in response to consecutive light level samples greater than said second threshold value for approximately 30 seconds.

12. The method of claim 1, wherein adjustment of the backlight intensity of said display screen and said keypad from brighter to dimmer is gradual whereas adjustment of the backlight intensity of said display screen and said keypad from dimmer to brighter is quick.