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    Display backlight headroom control systems and methods
    11.
    发明授权
    Display backlight headroom control systems and methods 有权

    公开(公告)号：US10678092B2

    公开(公告)日：2020-06-09

    申请号：US15711932

    申请日：2017-09-21

    Applicant: Apple Inc.

    Inventor： Ji Yeoul Ryoo ,  Asif Hussain ,  Jingdong Chen ,  Mohammad J. Navabi-Shirazi ,  Yanhui Xie

    IPC: G06F5/00 ,  G02F1/13357 ,  G09G3/34 ,  G09G3/36 ,  H05B45/00 ,  H05B45/37 ,  H05B45/46 ,  H05B47/10 ,  G02F1/1335 ,  G06F3/041

    Abstract: Aspects of the subject technology relate to display circuitry such as backlight control circuitry for operating parallel strings of light-emitting diodes (LEDs). A voltage supply circuit of the backlight control circuitry provides a common supply voltage to the strings of LEDs. Headroom control circuitry samples a residual voltage at the end of each string, determines a minimum of the residual voltages, and provides feedback, based on the determined minimum voltage, to the voltage supply circuit. A headroom control feedback loop may be provided including sampling lines coupled to the second end of each string of LEDs for sampling a residual voltage of each string. Headroom control circuitry may modify the supply voltage based on the minimum residual voltage. Sample-and-hold circuitry may be provided that holds the sampled residual voltages until the voltage supply circuit is ready for an update.

    Local display backlighting systems and methods
    12.
    发明授权
    Local display backlighting systems and methods 有权

    公开(公告)号：US10555389B2

    公开(公告)日：2020-02-04

    申请号：US16232913

    申请日：2018-12-26

    Applicant: Apple Inc.

    Inventor： Yanhui Xie ,  Asif Hussain ,  Jingdong Chen ,  Manisha P. Pandya

    IPC: H05B37/00 ,  H05B33/08 ,  G02F1/1335

    Abstract: Aspects of the subject technology relate to display of an electronic device. The display includes a backlight unit having a voltage source, a string of light-emitting diodes and a bypass switch for each light-emitting diode in the string. The string of light-emitting diodes can receive, at a first end, a supply voltage from the voltage source. The bypass switch for each light-emitting diode is controllable to pulse-width-modulate that light-emitting diode. The headroom voltage feedback circuit is coupled to a second end of the string.

    PFM scheme for boost and flyback converter in LED backlight application
    13.
    发明授权
    PFM scheme for boost and flyback converter in LED backlight application 有权

    公开(公告)号：US10009968B2

    公开(公告)日：2018-06-26

    申请号：US15069724

    申请日：2016-03-14

    Applicant: Apple Inc.

    Inventor： Jingdong Chen ,  Asif Hussain ,  Behzad Mohtashemi ,  Manisha P. Pandya ,  Mohammad J. Navabi-Shirazi

    IPC: H05B33/08 ,  G09G3/34

    CPC classification number: H05B33/0815 ,  G09G3/3406 ,  G09G2330/06 ,  H05B33/086

    Abstract: This application relates to systems, methods, and apparatus for controlling a switching frequency of a boost or flyback converter to be above an audible frequency range when operating the boost or flyback converter in a pulse frequency modulation (PFM) mode. The boost or flyback converter uses one or more switches for converting power for a display panel. In order to boost the switching frequency when operating in the PFM mode, the boost or flyback converter can selectively implement certain current and/or voltage limits for pulses that are generated as a result of the switching. The current and/or voltage limits can be set according to a load of the boost or flyback converter, and a correspondence between the current and/or voltage limits and the loads can be stored in a lookup table accessible to the boost or flyback converter.

    Slew rate enhancement for transient load step response
    14.
    发明授权
    Slew rate enhancement for transient load step response 有权

    公开(公告)号：US09673701B2

    公开(公告)日：2017-06-06

    申请号：US15050152

    申请日：2016-02-22

    Applicant: Apple Inc.

    Inventor： Behzad Mohtashemi ,  Asif Hussain ,  Manisha P. Pandya ,  Mohammad J. Navabi-Shirazi ,  Nileshbhai J. Shah

    IPC: H02M3/156

    CPC classification number: H02M3/156 ,  H02M2003/1566

    Abstract: A power conversion circuit, such as a buck converter/regulator, includes a feedback loop operatively coupling the output voltage to the controller for the switching mechanism. The feedback loop includes an analog error amplifier that sources current to the controller when the output voltage falls below a predetermined reference voltage and sinks current from the controller when the output voltage rises above a predetermined reference voltage. The feedback loop further includes at least one of a sinking boost circuit that sinks additional current from the controller when the output voltage falls below a low voltage threshold or a sourcing boost circuit that sources additional current to the controller when the output voltage rises above a high voltage threshold. The boost circuits can include analog amplifiers, digital comparators, or a combination thereof.

    Methods and apparatus for improving backlight driver efficiency
    16.
    发明授权
    Methods and apparatus for improving backlight driver efficiency 有权
    提高背光驱动效率的方法和装置

    公开(公告)号：US09380672B2

    公开(公告)日：2016-06-28

    申请号：US13754640

    申请日：2013-01-30

    Applicant: Apple Inc.

    Inventor： Asif Hussain ,  Jingdong Chen ,  Mohammad Jafar Navabi-Shirazi ,  Manisha Pandya

    IPC: H05B33/08 ,  G09G3/34

    CPC classification number: H05B33/086 ,  G09G3/3406 ,  G09G2320/041 ,  G09G2320/062 ,  G09G2320/064 ,  H05B33/0863

    Abstract: An electronic device may be provided with display circuitry that includes a display timing controller, a backlight driver, a light source, and other associated backlight structures. The backlight control circuitry may generate a control signal having an adjustable duty cycle to the backlight driver. The backlight driver may include a boost converter, a current driver, and backlight control circuitry. The current driver may only be activated when the control signal is high. The backlight control circuitry may output an enable signal to the boost converter. The backlight control circuitry may activate the boost converter a predetermined amount of time before each rising clock edge in the control signal by asserting the enable signal for a longer period of time than when the control signal is high. The control signal and the enable signal may be deasserted at around the same times.

    Abstract translation: 电子设备可以设置有显示电路，显示电路包括显示定时控制器，背光驱动器，光源和其它相关联的背光结构。 背光控制电路可以产生对背光驱动器具有可调占空比的控制信号。 背光驱动器可以包括升压转换器，电流驱动器和背光控制电路。 当控制信号为高电平时，只能激活当前驱动器。 背光控制电路可以向升压转换器输出使能信号。 背光控制电路可以在控制信号中的每个上升时钟沿之前的预定时间量内激活升压转换器，该时间长于当控制信号为高时，将使能信号置为更长的时间段。 控制信号和使能信号可以在大约相同的时间被解除。

    COMPUTER KEYBOARD KEY SCAN SHARED MATRIX WITH AN INDIVIDUAL LED PER KEY
    17.
    发明申请
    COMPUTER KEYBOARD KEY SCAN SHARED MATRIX WITH AN INDIVIDUAL LED PER KEY 审中-公开
    计算机键盘按键扫描共享矩阵与单个LED每键

    公开(公告)号：US20140176352A1

    公开(公告)日：2014-06-26

    申请号：US14029534

    申请日：2013-09-17

    Applicant: APPLE INC.

    Inventor： Asif Hussain ,  Mohammad J. Navabi-Shirazi ,  Jingdong Chen ,  Manisha P. Pandya

    IPC: H01H13/83

    CPC classification number: H01H13/83 ,  G06F3/0202

    Abstract: Systems, devices, and methods for a shared matrix of shared row pins and/or column pins between a first array of keys and a second array of lights of a keyboard. A keyboard controller addresses the first array of keys and the second array of lights during a scanning period using the shared row pins and/or column pins. Each key is backlit by one or more lights of the second array of lights that may be individually controlled. The keyboard controller may drive the desired lights of a respective row while detecting key presses of the same row during the row interval using the shared row pins and/or column pins. In some embodiments, the keyboard controller may drive the desired lights of a row during driving interval of the row interval, and scan the keys of the row separately during a sensing interval of the row interval.

    Abstract translation: 用于共享行引脚和/或列引脚的共享矩阵在键的第一阵列与键盘的第二阵列之间的系统，设备和方法。 键盘控制器在扫描周期期间使用共享行引脚和/或列引脚来寻址第一阵列的键和第二阵列的光。 每个键都可以由可以单独控制的第二阵列灯的一个或多个灯背光。 键盘控制器可以在使用共享的行引脚和/或列引脚的行间隔期间检测同一行的按键时驱动相应行的期望的光。 在一些实施例中，键盘控制器可以在行间隔的驱动间隔期间驱动行的期望光，并且在行间隔的感测间隔期间单独扫描行的键。

    DISPLAY BACKLIGHT DRIVER IC CONFIGURATION
    18.
    发明申请
    DISPLAY BACKLIGHT DRIVER IC CONFIGURATION 有权
    显示器背光驱动器IC配置

    公开(公告)号：US20130278171A1

    公开(公告)日：2013-10-24

    申请号：US13659888

    申请日：2012-10-24

    Applicant: APPLE INC.

    Inventor： Alejandro Lara Ascorra ,  Shimon Elkayam ,  Asif Hussain ,  Brad Lee Patton ,  Steven J. Sfarzo ,  Eric G. Smith

    IPC: H05B37/02

    CPC classification number: H05B33/0842

    Abstract: One embodiment of a display backlight driver integrated circuit can be configured for operation in at least two different ways. A first method transfers data from an EEPROM to hardware registers prior to regular operation. A second method also transfers data from an EEPROM to registers. However, hardware registers can be overwritten with data accepted from a control bus, prior to regular operation. A keyboard driver IC can detect the presence or absence of a cable to an LED. If the cable is absent, the driver IC will not supply power for the LED. One embodiment of a keyboard and display backlight control system can be configured to allow substantially independent operation.

    Abstract translation: 显示器背光驱动器集成电路的一个实施例可被配置为以至少两种不同的方式进行操作。 第一种方法是在正常操作之前将数据从EEPROM传输到硬件寄存器。 第二种方法还将数据从EEPROM传输到寄存器。 但是，在正常操作之前，硬件寄存器可以被从控制总线接受的数据覆盖。 键盘驱动器IC可以检测到LED的电缆的存在或不存在。 如果电缆不存在，驱动器IC将不会为LED供电。 键盘和显示器背光控制系统的一个实施例可以被配置为允许基本独立的操作。

    Inductive Flying Capacitor Converters and Control Techniques Therefor
    19.
    发明申请
    Inductive Flying Capacitor Converters and Control Techniques Therefor 有权

    公开(公告)号：US20220376616A1

    公开(公告)日：2022-11-24

    申请号：US17324307

    申请日：2021-05-19

    Applicant: Apple Inc.

    Inventor： Zhiyuan Hu ,  Jingdong Chen ,  Yanhui Xie ,  Asif Hussain

    IPC: H02M3/07 ,  H02M1/08

    Abstract: Power converters can include a plurality of switching devices and a combination of one or more inductors and one or more flying capacitors. Both boost and buck converters may employ such topologies, and can achieve high efficiency and small size in at least some applications, including those with high conversion ratios. A control circuit can generate a first pair of complementary gate drive signals to drive a first complementary switch pairs and a second pair of complementary gate drive signals to drive a second complementary switch pair. The control circuit can vary a phase shift between the first pair of complementary gate drive signals and the second pair of complementary gate drive signals to regulate the flying capacitor voltage.

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