REDUCING POWER CONSUMPTION IN A PORTABLE ELECTRONIC DEVICE WITH A LUMINESCENT ELEMENT

• US 20100315535A1
• Filed: 02/13/2008
• Published: 12/16/2010
• Est. Priority Date: 02/13/2008
• Status: Abandoned Application

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Monfils, Sylvain, Nurit, Vincent, Richaud, Stephane
• Application Number:
  US12/866,247
• Publication Number:
  US 20100315535A1
• Time in Patent Office: Days
• US Class Current: 348/234
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness 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

Abstract

A portable device including at least one luminescent element, a camera including an image sensor for activation to produce an electrical image signal representative of an image sensed by the image sensor, and a camera signal processor including a camera memory for storing the image signal for subsequent reproduction of the image, the device also including a luminescence controller for controlling a brightness of the luminescent element, the camera signal processor is also arranged to activate the image sensor intermittently to produce sample signals representative of ambient light during periods in which the image signal is not being stored in the camera memory, the luminescence controller being responsive to the sample signals to modulate progressively the brightness of the luminescent element as a function of a brightness of ambient light. In a portable device including at least one luminescent element, a plurality of human-interface actuators, at least one sensor responsive to an ambient variable relating to usage of the device, a timer and an activation controller for controlling activation and deactivation of the luminescent element, the activation controller is responsive to different conjunctions of signals from the actuators, the sensor and the timer to activate selectively and to extinguish the luminescent element, whereby to economise power consumption of the luminescent element when the conjunction of signals is indicative of user inactivity of the device.

Claims

1. A portable device Comprising:

at least one luminescent element;

a camera including an image sensor for activation to produce an electrical image signal representative of an image sensed by the image sensor;

a camera signal processor including a camera memory for storing said image signal for subsequent reproduction of said image;

a luminescence controller for controlling a brightness of said luminescent element;

wherein said camera signal processor is also arranged to activate said image sensor intermittently to produce sample signals representative of ambient light during periods in which said image signal is not being stored in said camera memory, said luminescence controller being responsive to said sample signals to control the brightness of said luminescent element as a function of a brightness of ambient light.

2. A portable device as claimed in claim 1, wherein said luminescence controller is responsive to said sample signals to modulate progressively the brightness of said luminescent element as a function of a brightness of ambient light.

3. A portable device as claimed in claim 1, also comprising a user interface application, and a display including said luminescent element operable to display an image derived from said image signal and/or data relating to said user interface application, wherein at least while said data relating to said user interface application is displayed said luminescence controller is responsive to said sample signals to modulate progressively said brightness of said luminescent element, whereby to control a brightness of display of said data as a function of a brightness of ambient light.

4. A portable device as claimed in claim 3, wherein said display comprises a display screen and said luminescent element includes a luminescent panel juxtaposed behind said display screen as a backlight.

5. A portable device as claimed in claim 3, wherein said luminescence controller is arranged to increase said brightness of said display in response to a value of said electrical image signal indicative of increased brightness of ambient light.

6. A portable device as claimed in claim 1, also comprising a keypad, at least one luminescent panel being juxtaposed behind said keypad as a backlight, wherein said luminescence controller is responsive to said sample signals to control a brightness of illumination of said keypad as a function of a brightness of ambient light.

7. A portable device as claimed in claim 1, wherein said luminescence controller is arranged to supply pulsed power to said luminescent element with a duty cycle that varies in order to modulate progressively the brightness of said luminescent element.

16. A portable device as claimed in claim 2, also comprising a user interface application, and a display including said luminescent element operable to display an image derived from said image signal and/or data relating to said user interface application, wherein at least while said data relating to said user interface application is displayed said luminescence controller is responsive to said sample signals to modulate progressively said brightness of said luminescent element, whereby to control a brightness of display of said data as a function of a brightness of ambient light.

17. A portable device as claimed in claim 4, wherein said luminescence controller is arranged to increase said brightness of said display in response to a value of said electrical image signal indicative of increased brightness of ambient light.

18. A portable device as claimed in claim 2, also comprising a keypad, at least one luminescent panel being juxtaposed behind said keypad as a backlight, wherein said luminescence controller is responsive to said sample signals to control a brightness of illumination of said keypad as a function of a brightness of ambient light.

19. A portable device as claimed in claim 3, also comprising a keypad, at least one luminescent panel being juxtaposed behind said keypad as a backlight, wherein said luminescence controller is responsive to said sample signals to control a brightness of illumination of said keypad as a function of a brightness of ambient light.

21. A portable device as claimed in claim 2, wherein said luminescence controller is arranged to supply pulsed power to said luminescent element with a duty cycle that varies in order to modulate progressively the brightness of said luminescent element.

22. A portable device as claimed in claim 3, wherein said luminescence controller is arranged to supply pulsed power to said luminescent element with a duty cycle that varies in order to modulate progressively the brightness of said luminescent element.

8. A portable device comprising:

at least one luminescent element;

a plurality of human-interface actuators, at least one sensor responsive to an ambient variable relating to usage of the device;

a timer and an activation controller for controlling activation and deactivation of said luminescent element;

wherein activation controller is responsive to different conjunctions of signals from said actuators, said sensor and said timer to activate selectively said luminescent element and to extinguish said luminescent element, when said conjunction of signals is indicative of user inactivity of said device.

9. A portable device as claimed in claim 8, wherein said at least one sensor comprises a movement sensor, and said activation controller is responsive to the conjunction of inactivity of said actuators and absence of movement of said device during a period defined by said timer to extinguish said luminescent element, said activation controller being responsive to a subsequent signal from said actuators or from said movement sensor to reactivate said luminescent element.

10. A portable device as claimed in claim 9, wherein said movement sensor comprises an accelerometer, and said activation controller is responsive to the conjunction of inactivity of said actuators and absence of acceleration during a period defined by said timer to extinguish said luminescent element, said activation controller being responsive to a subsequent signal from said actuators or from said accelerometer to reactivate said luminescent element.

11. A portable device as claimed in claim 8, wherein said at least one sensor comprises a light sensor responsive to a brightness of ambient light, and said activation controller is responsive to the conjunction of inactivity of said actuators and absence of ambient light during a period defined by said timer to extinguish said luminescent element, said activation controller being responsive to a subsequent signal from said actuators or from said light sensor to reactivate luminescence of said luminescent element.

12. A portable device as claimed in claim 11, comprising a camera comprising an image sensor for activation to produce an electrical image signal representative of an image sensed by the image sensor, and a camera signal processor including a camera memory for storing said image signal for subsequent reproduction of said image, wherein said light sensor comprises said image sensor and said camera signal processor is also arranged to actuate said image sensor intermittently to produce signal samples representative of ambient light during periods in which said image signal is not being stored in said camera memory.

13. A portable device as claimed in claim 12, wherein said luminescence controller is responsive to said sample signals to modulate progressively the brightness of said luminescent element as a function of a brightness of ambient light.

20. A portable device as claimed in claim 9, wherein said at least one sensor comprises a light sensor responsive to a brightness of ambient light, and said activation controller is responsive to the conjunction of inactivity of said actuators and absence of ambient light during a period defined by said timer to extinguish said luminescent element, said activation controller being responsive to a subsequent signal from said actuators or from said light sensor to reactivate luminescence of said luminescent element.

14. (canceled)

15. (canceled)