WO2020237895A1 - Procédé de réglage automatique de tension de sortie en fonction de l'énergie de la batterie d'un dispositif d'affichage mobile - Google Patents

Procédé de réglage automatique de tension de sortie en fonction de l'énergie de la batterie d'un dispositif d'affichage mobile Download PDF

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Publication number
WO2020237895A1
WO2020237895A1 PCT/CN2019/104619 CN2019104619W WO2020237895A1 WO 2020237895 A1 WO2020237895 A1 WO 2020237895A1 CN 2019104619 W CN2019104619 W CN 2019104619W WO 2020237895 A1 WO2020237895 A1 WO 2020237895A1
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WO
WIPO (PCT)
Prior art keywords
turned
output voltage
battery power
automatically adjusting
power
Prior art date
Application number
PCT/CN2019/104619
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English (en)
Chinese (zh)
Inventor
王海
Original Assignee
武汉华星光电半导体显示技术有限公司
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Application filed by 武汉华星光电半导体显示技术有限公司 filed Critical 武汉华星光电半导体显示技术有限公司
Publication of WO2020237895A1 publication Critical patent/WO2020237895A1/fr

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Classifications

    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control 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
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/06Adjustment of display parameters
    • G09G2320/0626Adjustment of display parameters for control of overall brightness
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02Details of power systems and of start or stop of display operation
    • G09G2330/021Power management, e.g. power saving
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02Details of power systems and of start or stop of display operation
    • G09G2330/026Arrangements or methods related to booting a display

Definitions

  • the invention relates to the field of automatic regulation of battery voltage and power consumption, in particular to
  • a method to automatically adjust the output voltage according to the battery power of the mobile display device is a method to automatically adjust the output voltage according to the battery power of the mobile display device.
  • the voltage configuration of each component in the existing mobile display device is based on the screen refresh rate of 60 Hz, which no longer meets the market demand. Therefore, there is a need for a new technology that can adjust the voltage configured to each component according to the current battery power of the display device, so that the battery power can be used efficiently and achieve the effect of power saving.
  • the object of the present invention is to provide a method for automatically adjusting the output voltage according to the battery power of the mobile display device, and to determine the on/off of each functional module in the mobile display device and the amount of battery power to adjust the output to the mobile display device The voltage of each component inside.
  • the present invention provides a method for automatically adjusting the output voltage according to the battery power of the mobile display device, the steps of which include:
  • step S1 After the mobile display device is powered on, the system determines whether the automatic voltage adjustment technology is turned on, if it is turned on, go to S2, if not, go to step S4;
  • the power detector of the system detects the battery power and sends the command corresponding to the detected power to the drive integrated circuit according to the preset power-command correspondence;
  • the drive integrated circuit determines the output voltage according to the instruction and whether one or more functional modules are turned on;
  • the drive integrated circuit determines the output voltage according to whether one or more of the functional modules are turned on.
  • the voltage automatic adjustment technology can determine whether to automatically turn on according to the settings of the device to which it is applied before the last shutdown, and can be manually turned on/off at any time on the device in the turned on state.
  • the functional modules include high frequency application mode (high frequency, HF), ambient light sensor (ambient brightness sensor, ABS), dark screen display (always on One or more of display, AOD) and high brightness mode (HBM).
  • high frequency application mode high frequency, HF
  • ambient light sensor ambient brightness sensor, ABS
  • dark screen display always on One or more of display, AOD
  • high brightness mode HBM
  • the power-command correspondence relationship is stored in the power detector.
  • Command 1 The corresponding command for power ⁇ 5% is: directly determine the output voltage
  • Command 2 20% ⁇ electricity>5% corresponds to the command: judge whether the ambient light sensor (AOD) is turned on;
  • Instruction 3 The instruction corresponding to the battery power> 20% is: Determine whether the high frequency application mode (HF) is turned on.
  • the present invention also provides another method for automatically adjusting the output voltage according to the battery power of the mobile display device, the steps of which include:
  • the drive integrated circuit of the system uses an internal voltage comparator to detect the battery voltage to obtain the battery power;
  • the drive integrated circuit determines the output voltage according to the command corresponding to the preset power-command correspondence and whether one or more functional modules are turned on;
  • the drive integrated circuit determines the output voltage according to whether one or more of the functional modules are turned on.
  • the voltage automatic adjustment technology can determine whether to automatically turn on according to the settings of the device to which it is applied before the last shutdown, and can be manually turned on/off at any time on the device in the turned on state.
  • the functional module includes one or more of high frequency application mode (HF), ambient light sensor (ABS), dark screen display (AOD), and high brightness mode (HBM).
  • HF high frequency application mode
  • ABS ambient light sensor
  • AOD dark screen display
  • HBM high brightness mode
  • the electric quantity-command correspondence relationship is stored in the drive integrated circuit.
  • Command 1 The corresponding command for power ⁇ 5% is: directly determine the output voltage
  • Command 2 20% ⁇ electricity>5% corresponds to the command: judge whether the ambient light sensor (AOD) is turned on;
  • Instruction 3 The instruction corresponding to the battery power> 20% is: Determine whether the high frequency application mode (HF) is turned on.
  • the present invention provides a method for automatically adjusting the output voltage according to the battery power of a mobile display device, judging the on/off of each function module in the mobile display device and the amount of battery power to adjust the output to each of the mobile display devices
  • the voltage of the component and the brightness of the screen enable the battery power to be used efficiently, achieve the effect of power saving, and further increase the battery life.
  • FIG. 1 is a flow chart of a method for automatically adjusting the output voltage according to the battery power of a mobile display device provided by the present invention.
  • FIG. 2 is a flowchart of another method for automatically adjusting the output voltage according to the battery power of the mobile display device provided by the present invention.
  • FIG. 3 is a simplified schematic block diagram of a system in a method for automatically adjusting output voltage according to the battery power of a mobile display device according to Embodiment 1 of the present invention.
  • FIG. 4 is a simplified schematic block diagram of a system in a method for automatically adjusting output voltage according to the battery power of a mobile display device according to Embodiment 2 of the present invention.
  • FIG. 5 is a technical flow chart of a method for automatically adjusting the output voltage according to the battery power of the mobile display device according to Embodiment 1 and Embodiment 2 of the present invention.
  • FIG. 6 is a voltage configuration table of a method for automatically adjusting the output voltage according to the battery power of the mobile display device according to the embodiment 1 and the embodiment 2 of the present invention.
  • FIG. 1 is a flow chart of a method for automatically adjusting the output voltage according to the battery power of a mobile display device provided by the present invention. The specific steps are described in Embodiment 1.
  • This embodiment provides a method for automatically adjusting the output voltage according to the battery power of the mobile display device.
  • the steps include: after the mobile display device is powered on (Power on), the system determines whether the automatic voltage adjustment technology is turned on, and if the system determines the voltage The automatic adjustment technology is turned on.
  • the power detector of the system detects the battery power and sends the command corresponding to the detected power to the drive integrated circuit according to the preset power-command correspondence.
  • the drive integrated circuit determines the output voltage according to the instruction and whether one or more functional modules are turned on; if the system determines that the automatic voltage adjustment technology is not turned on, the drive integrated circuit directly based on one or more Whether the function module is open or not determines the output voltage.
  • the voltage automatic adjustment technology can determine whether to automatically turn on according to the settings of the device to which it is applied before the last shutdown, and can be manually turned on/off at any time when the device is turned on.
  • the functional module includes one or more of high frequency application mode (HF), ambient light sensor (ABS), dark screen display (AOD), and high brightness mode (HBM).
  • HF high frequency application mode
  • ABS ambient light sensor
  • AOD dark screen display
  • HBM high brightness mode
  • the power-command correspondence relationship is stored in the power detector.
  • the system determines whether the ambient light sensor (ABS) is turned on, and it is not turned on by default. If the ambient light sensor (ABS) is not turned on, it is determined whether the dark screen display (AOD) is turned on, and if the dark screen display (AOD) is not turned on, then the T2 scheme in FIG.
  • the voltage setting corresponding to each component in the mobile display device if the dark screen display (AOD) is turned on, the voltage setting corresponding to each component in the mobile display device is given according to the T1 scheme in Figure 6; if the ambient light sensor (ABS) is turned on, it is determined whether the high-brightness mode (HBM) is turned on, and it is not turned on by default. If the high-brightness mode (HBM) is not turned on, the voltage corresponding to each component in the mobile display device is given according to the T2 scheme in Figure 6 Settings; if the high-brightness mode (HBM) is turned on, the corresponding voltage settings for each component in the mobile display device are given according to the T3 scheme in FIG. 6.
  • the system determines whether the battery power Q is> 5%, and if Q ⁇ 5%, the mobile display is given according to the T1 scheme in FIG. 6
  • the voltage settings corresponding to each component in the device if Q>5%, then judge whether Q>20%, if 20% ⁇ Q>5%, then judge whether the ambient light sensor (ABS) is turned on, if the If the ambient light sensor (ABS) is not turned on, it is determined whether the dark screen display (AOD) is turned on, and if the dark screen display (AOD) is not turned on, the mobile display device will be given to the mobile display device according to the T4 scheme in Figure 6
  • the voltage setting corresponding to each component in the mobile display device if the dark screen display (AOD) is turned on, the voltage setting corresponding to each component in the mobile display device is given according to the T1 scheme in FIG.
  • the ambient light sensor ( ABS) if the ambient light sensor ( ABS) is turned on, then it is determined whether the high-brightness mode (HBM) is turned on. If the high-brightness mode (HBM) is not turned on, the corresponding voltage settings for each component in the mobile display device are given according to the T4 scheme in Figure 6 ; If the high-brightness mode (HBM) is turned on, the corresponding voltage settings for each component in the mobile display device are given according to the T5 scheme in Figure 6; if Q>20%, the high-frequency application mode (HF ) Whether it is turned on, if the high frequency application mode (HF) is turned on, the corresponding voltage settings for each component in the mobile display device are given according to the T6 scheme in FIG.
  • HBM high-brightness mode
  • the mobile display device can display part of the screen when the screen is off.
  • the mobile display device can sense the brightness of the surrounding environment and automatically adjust the screen brightness of the mobile display device.
  • the upper limit of the screen refresh rate of the mobile display device is increased.
  • the screen brightness of the mobile display device is adjusted to the upper limit.
  • FIG. 2 is a flowchart of another method for automatically adjusting the output voltage according to the battery power of the mobile display device provided by the present invention. The specific steps are described in Embodiment 2.
  • This embodiment provides a method for automatically adjusting the output voltage according to the battery power of the mobile display device.
  • the steps include: after the mobile display device is powered on (Power on), the system determines whether the automatic voltage adjustment technology is turned on, and if the system determines the voltage The automatic adjustment technology is turned on.
  • the internal drive integrated circuit of the system has a voltage comparator.
  • the voltage comparator detects the voltage of the battery to determine the electric quantity, and obtains it according to the preset electric quantity-command correspondence relationship.
  • the drive integrated circuit determines the output voltage according to the instruction and whether one or more functional modules are turned on; if the system determines that the automatic voltage adjustment technology is not turned on, the drive integrated circuit directly based on one or more Whether the function module is turned on determines the output voltage.
  • the voltage automatic adjustment technology can determine whether to automatically turn on according to the settings of the device to which it is applied before the last shutdown, and can be manually turned on/off at any time when the device is turned on.
  • the functional module includes one or more of high frequency application mode, ambient light sensor (ABS), dark screen display (AOD), and high brightness mode (HBM).
  • ABS ambient light sensor
  • AOD dark screen display
  • HBM high brightness mode
  • the power-command correspondence relationship is stored in the power detector.
  • the system determines whether the ambient light sensor (ABS) is turned on, and it is not turned on by default. If the ambient light sensor (ABS) is not turned on, it is determined whether the dark screen display (AOD) is turned on, and if the dark screen display (AOD) is not turned on, then the T2 scheme in FIG.
  • the voltage setting corresponding to each component in the mobile display device if the dark screen display (AOD) is turned on, the voltage setting corresponding to each component in the mobile display device is given according to the T1 scheme in Figure 6; if the ambient light sensor (ABS) is turned on, it is determined whether the high-brightness mode (HBM) is turned on, and it is not turned on by default. If the high-brightness mode (HBM) is not turned on, the voltage corresponding to each component in the mobile display device is given according to the T2 scheme in Figure 6 Settings; if the high-brightness mode (HBM) is turned on, the corresponding voltage settings for each component in the mobile display device are given according to the T3 scheme in FIG. 6.
  • the system determines whether the battery power Q is> 5%, and if Q ⁇ 5%, the mobile display is given according to the T1 scheme in FIG. 6
  • the voltage settings corresponding to each component in the device if Q>5%, then judge whether Q>20%, if 20% ⁇ Q>5%, then judge whether the ambient light sensor (ABS) is turned on, if the If the ambient light sensor (ABS) is not turned on, it is determined whether the dark screen display (AOD) is turned on, and if the dark screen display (AOD) is not turned on, the mobile display device will be given to the mobile display device according to the T4 scheme in Figure 6
  • the voltage setting corresponding to each component in the mobile display device if the dark screen display (AOD) is turned on, the voltage setting corresponding to each component in the mobile display device is given according to the T1 scheme in FIG.
  • the ambient light sensor ( ABS) if the ambient light sensor ( ABS) is turned on, then it is determined whether the high-brightness mode (HBM) is turned on. If the high-brightness mode (HBM) is not turned on, the corresponding voltage settings for each component in the mobile display device are given according to the T4 scheme in Figure 6 ; If the high-brightness mode (HBM) is turned on, the corresponding voltage settings for each component in the mobile display device are given according to the T5 scheme in Figure 6; if Q>20%, the high-frequency application mode (HF ) Whether it is turned on, if the high frequency application mode (HF) is turned on, the corresponding voltage settings for each component in the mobile display device are given according to the T6 scheme in FIG.
  • HBM high-brightness mode
  • the mobile display device can display part of the screen when the screen is off.
  • the mobile display device can sense the brightness of the surrounding environment and automatically adjust the screen brightness of the mobile display device.
  • the upper limit of the screen refresh rate of the mobile display device is increased.
  • the screen brightness of the mobile display device is adjusted to the upper limit.

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  • Engineering & Computer Science (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)
  • Secondary Cells (AREA)
  • Controls And Circuits For Display Device (AREA)

Abstract

L'invention concerne un procédé de réglage automatique de tension de sortie en fonction de l'énergie de la batterie d'un dispositif d'affichage mobile, comprenant : un système déterminant si chaque module fonctionnel à l'intérieur d'un dispositif d'affichage mobile est allumé/éteint et déterminant la quantité d'énergie de la batterie de manière à ajuster la tension délivrée à chaque ensemble à l'intérieur du dispositif d'affichage mobile ainsi que la luminosité de l'écran de telle sorte que l'énergie de la batterie soit appliquée plus efficacement, ce qui permet d'obtenir un effet d'économie d'énergie, et d'augmenter davantage la durée de vie de la batterie.
PCT/CN2019/104619 2019-05-27 2019-09-06 Procédé de réglage automatique de tension de sortie en fonction de l'énergie de la batterie d'un dispositif d'affichage mobile WO2020237895A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201910448800.2 2019-05-27
CN201910448800.2A CN110189674A (zh) 2019-05-27 2019-05-27 根据移动显示设备的电池电量自动调节输出电压的方法

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WO2020237895A1 true WO2020237895A1 (fr) 2020-12-03

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CN110189674A (zh) * 2019-05-27 2019-08-30 武汉华星光电半导体显示技术有限公司 根据移动显示设备的电池电量自动调节输出电压的方法
CN112397027B (zh) 2020-12-11 2021-09-21 上海天马有机发光显示技术有限公司 一种驱动模块及其电压生成方法、显示装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6603469B1 (en) * 2000-08-28 2003-08-05 Palm, Inc. Method and apparatus for user selectable display mode for intelligently enhancing battery life
CN101071542A (zh) * 2006-05-12 2007-11-14 乐金电子(昆山)电脑有限公司 显示装置的亮度调节装置及方法
CN101388178A (zh) * 2007-09-11 2009-03-18 奇景光电股份有限公司 电子装置中动态背光控制的元件及方法
CN101789210A (zh) * 2009-01-23 2010-07-28 英属开曼群岛商恒景科技股份有限公司 延长电子装置使用时间的系统和方法
CN104424901A (zh) * 2013-09-11 2015-03-18 中兴通讯股份有限公司 一种屏幕亮度调节的方法及装置
CN110189674A (zh) * 2019-05-27 2019-08-30 武汉华星光电半导体显示技术有限公司 根据移动显示设备的电池电量自动调节输出电压的方法

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100490271C (zh) * 2005-07-22 2009-05-20 鸿富锦精密工业(深圳)有限公司 电池省电系统及方法
CN101287037A (zh) * 2008-05-30 2008-10-15 德信无线通讯科技(北京)有限公司 一种手机节电方法及装置
US20120108224A1 (en) * 2009-01-09 2012-05-03 Qualcomm Incorporated Using quality of service to control hardware for low battery scenarios
EP3201905B1 (fr) * 2014-09-30 2020-07-01 Microsoft Technology Licensing, LLC Affichage de contenu sur un dispositif d'affichage en mode d'économie d'énergie
CN106304280B (zh) * 2015-05-11 2020-03-24 上海和辉光电有限公司 一种电源控制方法及系统以及移动终端
US11122510B2 (en) * 2015-05-27 2021-09-14 Verizon Patent And Licensing Inc. Power and notification management for a wearable device
CN106101428B (zh) * 2016-06-30 2020-04-10 努比亚技术有限公司 一种控制方法及移动终端
CN106413064B (zh) * 2016-11-30 2019-09-20 努比亚技术有限公司 移动终端控制装置及方法
CN106900037B (zh) * 2017-01-16 2020-09-01 努比亚技术有限公司 一种显示方法及终端
CN106817753B (zh) * 2017-03-10 2020-04-17 Oppo广东移动通信有限公司 一种切换背景灰阶进行省电的方法、装置及移动终端
CN108174436A (zh) * 2017-12-27 2018-06-15 北京传嘉科技有限公司 显示方法及装置
CN109618397A (zh) * 2018-11-15 2019-04-12 安徽信果网络科技有限公司 一种基于微信小程序手机电量优化以及使用预警系统

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6603469B1 (en) * 2000-08-28 2003-08-05 Palm, Inc. Method and apparatus for user selectable display mode for intelligently enhancing battery life
CN101071542A (zh) * 2006-05-12 2007-11-14 乐金电子(昆山)电脑有限公司 显示装置的亮度调节装置及方法
CN101388178A (zh) * 2007-09-11 2009-03-18 奇景光电股份有限公司 电子装置中动态背光控制的元件及方法
CN101789210A (zh) * 2009-01-23 2010-07-28 英属开曼群岛商恒景科技股份有限公司 延长电子装置使用时间的系统和方法
CN104424901A (zh) * 2013-09-11 2015-03-18 中兴通讯股份有限公司 一种屏幕亮度调节的方法及装置
CN110189674A (zh) * 2019-05-27 2019-08-30 武汉华星光电半导体显示技术有限公司 根据移动显示设备的电池电量自动调节输出电压的方法

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