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GB2391752A - Reducing power consumption of display illumination - Google Patents

Reducing power consumption of display illumination Download PDF

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Publication number
GB2391752A
GB2391752A GB0218317A GB0218317A GB2391752A GB 2391752 A GB2391752 A GB 2391752A GB 0218317 A GB0218317 A GB 0218317A GB 0218317 A GB0218317 A GB 0218317A GB 2391752 A GB2391752 A GB 2391752A
Authority
GB
United Kingdom
Prior art keywords
power consumption
leds
electronic device
display
reducing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB0218317A
Other versions
GB0218317D0 (en
Inventor
Richard Ormson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Technologies UK Ltd
Original Assignee
NEC Technologies UK Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Technologies UK Ltd filed Critical NEC Technologies UK Ltd
Priority to GB0218317A priority Critical patent/GB2391752A/en
Publication of GB0218317D0 publication Critical patent/GB0218317D0/en
Publication of GB2391752A publication Critical patent/GB2391752A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/02—Constructional features of telephone sets
    • H04M1/22—Illumination; Arrangements for improving the visibility of characters on dials
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406—Control of illumination source
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0209—Power saving arrangements in terminal devices
    • H04W52/0261—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level
    • H04W52/0267—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level by controlling user interface components
    • H04W52/027—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level by controlling user interface components by controlling a display operation or backlight unit
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0626—Adjustment of display parameters for control of overall brightness
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0626—Adjustment of display parameters for control of overall brightness
    • G09G2320/0633—Adjustment of display parameters for control of overall brightness by amplitude modulation of the brightness of the illumination source
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G09G2330/021—Power management, e.g. power saving
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G09G2330/021—Power management, e.g. power saving
    • G09G2330/022—Power management, e.g. power saving in absence of operation, e.g. no data being entered during a predetermined time
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2360/00—Aspects of the architecture of display systems
    • G09G2360/14—Detecting light within display terminals, e.g. using a single or a plurality of photosensors
    • G09G2360/144—Detecting light within display terminals, e.g. using a single or a plurality of photosensors the light being ambient light
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M2250/00—Details of telephonic subscriber devices
    • H04M2250/12—Details of telephonic subscriber devices including a sensor for measuring a physical value, e.g. temperature or motion
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Human Computer Interaction (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Liquid Crystal Display Device Control (AREA)

Abstract

The power consumption of an electronic device, preferably a portable device with a power supply, e.g. a mobile phone or laptop computer, is reduced by detecting when the device is in use, detecting the background lighting conditions in which the device is being used and controlling the level of illumination of a display of the device in response to the background lighting conditions. The display, for example an LCD, may be backlit by one or more LEDs 560 and the illumination level of the display may be changed either by varying the LED brightness, using means 540 to varying the current through or voltage across an LED, or by altering the number of LEDs that are lit, via switching means 550. The ambient lighting conditions may be detected periodically, e.g. using a photodetector 520.

Description

239 1 752
- 1 Method and Apparatus for Reducing Power in a Portable Device The present invention relates to a method and apparatus for reducing power consumption in a portable device.
5 With the emergence of third generation mobile telephone technology one of the biggest problems facing designers is that of reducing the power consumption of the mobile device. The three largest power consumptions in the handsets are those of the radio, the baseband (the section lo of electronics which performs high speed processing of radio information) and the display.
Modern mobile handsets usually incorporate a liquid crystal display (LCD) with some form of backlighting. The power drawn by the LCD and the backlight can represent up to 50% 15 of the power used by the device at any time. With third generation mobile telephone devices that include features such as web browsing and multi-media messaging, the screen of the device will be in use and therefore active for much longer periods than has been the case in previous mobile 20 handset technology. Furthermore, the new style displays preferably include white LED backlights which consume more power than the previous generation of monochrome units.
Therefore, the battery life of the new handsets in operation will be far reduced compared with known mobile 25 handsets. This is not desirable and it would be useful to extend the battery life, or reduce the power consumption, of the third generation handsets in the active mode.
Existing backlight systems comprise a number of light emitting diodes (LEDs), which are typically mounted on the 30 sides of the display, and a diffuser or reflector which is used to spread the light from the LED across the entire display. The LEDs are either on or off and the device has
- 2 no control over the intensity of the lighting produced by the LEDs.
We have appreciated that it would be beneficial to provide a mobile handset in which the level of illumination of the s display can be varied in dependence on the lighting conditions in which the device is being used. In this way, power consumption due to display illumination can be optimized since, in conditions when illumination is not required or is required at a minimal level, the power 10 required for the lighting will be reduced. In use, the required level of lighting depends on the background
conditions in which the device is being used. In very dark or very bright conditions a low level of lighting is required to allow the user to read the display. In 15 intermediate lighting conditions, variations in the lighting intensity provided by the LEDs are required. In certain conditions lighting from the LEDs to illuminate the screen may not be required at all. Optimizing the power consumption due to display illumination will help to extend 20 the battery life in the device.
Embodiments of the present invention vary the level of lighting supplied by the display LEDs in dependence on the background lighting conditions in which the device is being
used. Preferably a photodetector or some other light Is sensitive device detects the background level of lighting.
This detector is positioned upon the mobile communication device, and the level of light emitted from the display LEDs is controlled in dependence on the output of this detection. 30 One embodiment of the present invention controls the level of illumination provided by the display LEDs by varying the number of LEDs which are active in dependence on the background lighting conditions.
Another embodiment controls the voltage across or the current through the LEDs in dependence on background
lighting conditions. This will vary the brightness of light emitted by each LED.
5 Further embodiments control both the number of display LEDs which are active at a particular time and the voltage and current applied to the LEDs.
The invention is defined in its various aspects in the appended claims to which reference should now be made.
lo Embodiments of the present invention will now be described in detail by way of example with reference to the accompanying drawings in which: Figure 1 is a representation of a typical display in a mobile handset.
15 Figure 2 is a representation of an electronic circuit controlling the display LEDs in a known mobile handset.
Figure 3 is a representation of an electric circuit controlling the outputs of the display LEDs in a first embodiment of the present invention.
20 Figure 4 is a representation of an electronic circuit controlling the output of the display LEDs in a second embodiment of the present invention.
Figure 5 is a representation of an electronic circuit controlling the output of the display LEDs in a third 25 embodiment of the present invention.
Figure 6 is a flow diagram indicating how the level of illumination of the display screen is set in dependence on
the background conditions in which the device is being
used. Figure 7 is a typical profile of the illumination level of a display as a function of the background lighting
S conditions.
Figure 1 shows a display (10) of a mobile device. The display includes a plurality of LEDs (20) which are positioned around the display. The LEDs may be positioned in any configuration around the edge of the display and are lo not limited to being positioned on the top and bottom of the screen. Furthermore, the number of LEDs is not limited to six. The display further includes a diffuser or reflector (30) which is positioned at the back of the screen. The diffuser (30) is used to direct the light 15 across the screen to enable the entire screen to be illuminated rather than just the area in the immediate vicinity of the LEDs (20).
The electrical circuit used to power the LEDs in a mobile device with a display such as that shown in Figure 1 is 20 illustrated in Figure 2. The circuit includes a power supply (100) which is an internal power supply in the device. Alternatively, the display may have a dedicated power supply. The circuit further includes a detection circuit (110) which is used to identify when the device is 25 in use. Typically, the detection circuit will be activated when the user presses a button on the keypad.
Alternatively different techniques by which the detection circuit is triggered may be used. On activation of the detection circuit the lighting circuit will be closed and 30 the LEDs will be lit.
Figure 3 shows an electronic circuit which is used to illuminate the display LEDs of an electronic device in
- 5 - accordance with a first embodiment of the present invention. The circuit includes a power supply (200) which may be the central power supply of the device. The devcice includes a detection circuit (210) to detect when the 5 device is in use. The device further includes a photodetector (220) which is positioned on the device. The photodetector is used to detect the background lighting
conditions in which the device is being used. Typically, the photodetector will be positioned on the surface of the 10 device in the vicinity of the display. It is important that the photodetector is positioned such that it is not affected by the light from the display LEDs or concealed by the user's hand during use.
On detecting that the device is in use, the photodetector 15 then measures the intensity of background lighting. A
background intensity signal is then forwarded to a control
unit (230) which compares the measured background intensity
with a look up table to determine the required level of illumination for the display. The control unit has a 20 plurality of output lines (240) each connected to individual switches (250) and then to separate LEDs (260).
The switches control whether each LED is on or off. The LEDs are connected in parallel. In very bright conditions, when the photodetector detects a large level of light, only 2s a limited number of LEDs will be activated. The switches connected to the remaining LEDs will remain open such that those LEDs will not be lit. In contrast, in intermediate conditions where visibility is low, the control unit will require that all switches are closed to allow all LEDs to 30 be lit, thus providing maximum illumination of the display of the handset.
In the embodiment of Figure 3, it may be possible that on the transitions between the background light range, the
number of LEDs required will vary. In this situation
- 6 certain of the LEDs may flicker on and off as the level of light falling on the photodetector varies between the two ranges. This situation is not desirable and, in order to avoid this situation, a suitable hysteresis algorithm is 5 programmed into the control unit such that any rapid, but oscillating, changes in the light detected by the photodetector do not produce rapid changes in the number of LEDs lit over a given time. Also, to prevent feedback developing, the photodetector must be mounted in a position lo out of direct line with the LEDs.
Figure 4 shows a circuit used in an electronic device in accordance with a second embodiment of the present invention. The device includes a detection circuit (310), a photodetector (320) and a control unit (330). Again, on 15 detecting that the device is in use, the photodetector (320) measures the intensity of background illumination.
The control unit compares the measured background intensity
with a look up table and determines the level of light requires from the LEDs to illuminate the display. The 20 control unit has an output (340) connected to a variable current source (350) which is positioned within the display lighting circuit. The control unit controls the variable current source which varies the current through the LEDs (360) and therefore the brightness of the LEDs. In 25 conditions when low level screen illumination is required the control unit sets variable current source to a reduced current. However, when a high level of screen illumination is required the variable current source will be set to a high current order to increase the brightness of the LEDs.
30 Preferably the resolution of the control unit is sufficiently high to give apparently continuously variable control of illumination intensity. In certain embodiments the variable current source may be replaced with a variable resistor.
- 7 - Figure 5 shows a circuit used in an electronic device in accordance with a third embodiment of the present invention. This embodiment combines the circuits of Figures 3 and 4 and the control unit (530) controls a 5 variable current source (S40) and a plurality of switches (550) which are positioned in the lighting circuit and connected to individual LEDs (560). The control unit can control both the current through the LEDs and whether each LED is on or off. This circuit will provide a maximum lo level of control over the illumination of the display.
Figure 6 is a flow diagram showing the sequence of steps by which the display LEDs are lit in dependence on the background lighting conditions in which the device is being
used. At 600 the device determines if the device is active. Typically this is triggered when the user presses a key on the keypad. When this is detected, the display lighting circuit will be completed at 610. If not detected then the lighting circuit remains open until activation of the device is detected at 600. If the device is active at 20 600, the level of light received by the photodetector is determined at 620. The level of light is then compared to a look-up table at 630. At 640 this look up table provides control values for the control unit. The control unit then sets the variable current source and/or the switch in the 25 display LED circuit in dependence on using these control values. The level of background lighting and activity of
the device are monitored periodically in order that the illumination of the device can be regularly updated.
Figure 7 shows a typical illumination profile of the display of a mobile handset as a function of the background
conditions in which the handset is being used. In the darkest conditions, the screen will be required to be illuminated, however maximum illumination will not be required. In the brightest of conditions, typically, no
illumination of the screen will be required, since the user will be able to read the screen under the brightness of the background light. The illumination profile will vary
between devices and should be programmed individually into s the software of each electronic device.
It will be clear to those skilled in the art that the applications of the present invention extend beyond use in a mobile communication device. The method for controlling the illumination of the display in dependence on the lo background lighting conditions can be applied to any
display screen which is to be viewed by a user. Examples of further applications include personal and laptop computer screens and any other electronic device having a display screen.

Claims (17)

- 9 - Claims
1. A method for reducing the power consumption in an electronic device comprising the steps of; detecting if the device is in use, 5 detecting the background lighting conditions in which
the device is being used, and controlling the level of illumination of the display in dependence on the background lighting conditions.
2. A method for reducing power consumption in an lo electronic device according to claim 1 in which the display is illuminated by at least one light emitting diode (LED).
3. A method for reducing power consumption in an electronic device according to claim 1 in which the display is illuminated by at least two light emitting diodes (LED) 15 in which the step of controlling the level of illumination of the display comprises varying the number of LEDs which are lit.
4. A method for reducing power consumption in an electronic device according to claim 2 or 3 in which the 20 step of controlling the level of illumination of the display comprises varying the brightness of the LEDs.
5. A method for reducing power consumption in an electronic device according to claim 4 including the step of varying the brightness of the LEDs by varying the 25 current through the LEDs.
6. A method for reducing power consumption in an electronic device according to claim 4 or 5 including the step of varying the brightness of the LEDs by varying the voltage across the LEDs.
- 10
7. A method for reducing power consumption in an electronic device according to any preceding claim including the step of periodically detecting the background
lighting conditions.
5
8. A method for reducing power consumption in an electronic device substantially as herein described, with reference to figures 3, 4 or 5 of the accompanying drawings.
9. An apparatus for reducing the power consumption in an lo electronic device comprising; a power supply, means for detecting if the device is in use, means for detecting the background lighting conditions
in which the device is being used, 15 a control unit for controlling the level of illumination of the display in dependence on the background
lighting conditions.
10. An apparatus for reducing the power consumption in an electronic device according to claim 9 wherein the means 20 for detecting the background lighting conditions is a
photodetector.
11. An apparatus for reducing the power consumption in an electronic device according to claim 9 or 10 wherein the display is illuminated by at least one light emitting diode 25 (LED).
12. An apparatus for reducing the power consumption in an electronic device according to claim 9 or 10 wherein the display is illuminated by at least two light emitting diodes (LED) wherein the level of illumination of the 30 display is varied by varying the number of LEDs which are lit.
- 11 -
13. An apparatus for reducing the power consumption in an electronic device according to claim 11 or 12 wherein the i level of illumination of the display is varied by varying l the brightness of the LEDs.
5
14. An apparatus for reducing the power consumption in an electronic device according to claim 13 wherein the brightness of the LEDs is varied by varying the current: through the LEDs.
15. An apparatus for reducing the power consumption in an 10 electronic device according to claim 13 or 14 wherein the brightness of the LEDs is varied by varying the voltage across the LEDs.
16. An apparatus for reducing power consumption in an electronic device according to claim 9, 10, 11, 12, 13, 14 15 or 15 wherein the background lighting conditions are
detected periodically.
17. An apparatus for reducing power consumption in an electronic device substantially as herein described, with reference to figures 3, 4 or 5 of the accompanying drawings.
17. An apparatus for reducing power consumption in an electronic device substantially as herein described, with reference to figures 3, 4 or 5 of the accompanying 20 drawings.
À re e A (: ll Amendments to the chime have been filed as follows 1. A method for reducing the power consumption in an electronic device comprising the steps of; detecting if the device is in use, 5 detecting the background lighting conditions in which
the device is being used, and controlling the level of illumination of the display with a hysteresis algorithm in dependence on the background
lighting conditions.
lo 2. A method for reducing power consumption in an electronic device according to claim 1 in which the display is illuminated by at least one light emitting diode (LED).
3. A method for reducing power consumption in an electronic device according to claim 1 in which the display is IS illuminated by at least two light emitting diodes (LED) in which the step of controlling the level of illumination of the display comprises varying the number of LEDs which are lit. 4. A method for reducing power consumption in an electronic to device according to claim 2 or 3 in which the step of controlling the level of illumination of the display comprises varying the brightness of the LEDs.
5. A method for reducing power consumption in an electronic device according to claim 4 including the step of varying as the brightness of the LEDs by varying the current through the LEDs.
6. A method for reducing power consumption in an electronic device according to claim 4 or 5 including the step of varying the brightness of the LEDs by varying the voltage 30 across the LEDs.
a. c À À d À À.
( IS 7. A method for reducing power consumption in an electronic device according to any preceding claim including the step of periodically detecting the background lighting
conditions. 8. A method for reducing power consumption in an electronic device substantially as herein described, with reference to figures 3, 4 or 5 of the accompanying drawings.
9. An apparatus for reducing the power consumption in an electronic device comprising; lo a power supply, means for detecting if the device is in use, -
means for detecting the background lighting conditions
in which the device is being used, a control unit for controlling the level of illumination of the display with a hysteresis algorithm in dependence on the background lighting conditions.
10. An apparatus for reducing the power consumption in an electronic device according to claim 9 wherein the means for detecting the background lighting conditions is a
to photodetector.
11. An apparatus for reducing the power consumption in an electronic device according to claim 9 or 10 wherein the display is illuminated by at least one light emitting diode (LED).
:5 12. An apparatus for reducing the power consumption in an electronic device according to claim 9 or 10 wherein the display is illuminated by at least two light emitting diodes (LED) wherein the level of illumination of the display is varied by varying the number of LEDs which are lit.
d: I: '' I::: t: f: ' ': $: f 1W 13. An apparatus for reducing the power consumption in an electronic device according to claim 11 or 12 wherein the level of illumination of the display is varied by varying the brightness of the LEDS.
5 14. An apparatus for reducing the power consumption in an electronic device according to claim 13 wherein the brightness of the LEDS is varied by varying the current through the LEDs.
15. An apparatus for reducing the power consumption in an lo electronic device according to claim 13 or 14 wherein the brightness of the LEDs is varied by varying the voltage across the LEDS.
16. An apparatus for reducing power consumption in an electronic device according to claim 9, 10, 11, 12, 13, 14 5 or 15 wherein the background lighting conditions are
detected periodically. -
GB0218317A 2002-08-07 2002-08-07 Reducing power consumption of display illumination Withdrawn GB2391752A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB0218317A GB2391752A (en) 2002-08-07 2002-08-07 Reducing power consumption of display illumination

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0218317A GB2391752A (en) 2002-08-07 2002-08-07 Reducing power consumption of display illumination

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GB0218317D0 GB0218317D0 (en) 2002-09-11
GB2391752A true GB2391752A (en) 2004-02-11

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Cited By (8)

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EP1569194A1 (en) * 2004-02-13 2005-08-31 Sony Ericsson Mobile Communications AB Portable electronic device controlled according to ambient illumination
WO2005081212A2 (en) * 2004-02-13 2005-09-01 Sony Ericsson Mobile Communications Ab Portable electronic device controlled according to ambient illumination
WO2005099105A1 (en) * 2004-04-05 2005-10-20 Sony Ericsson Mobile Communications Ab Sensor screen saver
EP1610171A1 (en) * 2004-06-21 2005-12-28 Kabushiki Kaisha Toyota Jidoshokki Illumination device and method
EP1696414A1 (en) * 2005-02-28 2006-08-30 Research In Motion Limited Backlight control for a portable computing device
WO2009013573A1 (en) * 2007-07-26 2009-01-29 Sony Ericsson Mobile Communications Ab Electronic device for hands-free operation of a portable communication device
EP2381657A1 (en) * 2010-04-26 2011-10-26 Research in Motion Limited System and method for illuminating a component of an electronic device
US8269715B2 (en) 2005-02-28 2012-09-18 Research In Motion Limited Backlight control for a portable computing device

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Publication number Priority date Publication date Assignee Title
CN114705809B (en) * 2022-02-21 2024-10-01 深圳绿米联创科技有限公司 Detection module control method and device and electronic equipment

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GB2322219A (en) * 1997-02-14 1998-08-19 Nec Corp Screen brightness control
GB2345410A (en) * 1998-12-31 2000-07-05 Nokia Mobile Phones Ltd User interface control in portable device; battery saving
JP2001223792A (en) * 2000-02-09 2001-08-17 Mitsubishi Electric Corp Portable telephone set
EP1195971A2 (en) * 2000-10-03 2002-04-10 Pioneer Corporation Portable information terminal apparatus having illumination control function
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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005081212A2 (en) * 2004-02-13 2005-09-01 Sony Ericsson Mobile Communications Ab Portable electronic device controlled according to ambient illumination
EP1569194A1 (en) * 2004-02-13 2005-08-31 Sony Ericsson Mobile Communications AB Portable electronic device controlled according to ambient illumination
WO2005081212A3 (en) * 2004-02-13 2009-01-08 Sony Ericsson Mobile Comm Ab Portable electronic device controlled according to ambient illumination
JP2007532069A (en) * 2004-04-05 2007-11-08 ソニー エリクソン モバイル コミュニケーションズ， エービー Sensor screen saver
WO2005099105A1 (en) * 2004-04-05 2005-10-20 Sony Ericsson Mobile Communications Ab Sensor screen saver
EP1610171A1 (en) * 2004-06-21 2005-12-28 Kabushiki Kaisha Toyota Jidoshokki Illumination device and method
EP1696414A1 (en) * 2005-02-28 2006-08-30 Research In Motion Limited Backlight control for a portable computing device
AU2006200863B2 (en) * 2005-02-28 2010-08-05 Blackberry Limited Backlight control for a portable computing device
AU2010241267B2 (en) * 2005-02-28 2012-02-02 Blackberry Limited Backlight control for a portable computing device
US8269715B2 (en) 2005-02-28 2012-09-18 Research In Motion Limited Backlight control for a portable computing device
WO2009013573A1 (en) * 2007-07-26 2009-01-29 Sony Ericsson Mobile Communications Ab Electronic device for hands-free operation of a portable communication device
EP2381657A1 (en) * 2010-04-26 2011-10-26 Research in Motion Limited System and method for illuminating a component of an electronic device
US8502473B2 (en) 2010-04-26 2013-08-06 Research In Motion Limited System and method for illuminating a component of an electronic device

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