公开(公告)号：US20200105185A1

公开(公告)日：2020-04-02

申请号：US16418882

申请日：2019-05-21

Applicant: Apple Inc.

Inventor： Jingdong Chen ,  Asif Hussain ,  Mohammad J. Navabi-Shirazi ,  Behzad Mohtashemi ,  Yanhui Xie ,  JY Ryoo ,  Ming Gu

IPC: G09G3/32 ,  F21S4/20 ,  H02J1/10

Abstract: A display may have an array of pixels illuminated using a backlight unit. The backlight unit may include multiple strings of light-emitting diodes (LEDs) and a boost converter for providing an output voltage to the multiple LED strings. The boost converter may have a single-phase single-switch, single-phase multi-switch, and/or multi-phase multi-switch configuration, where the switches are turned off when the peak current is reached. When transitioning from a single phase to a dual phase operation, the second (slave) phase current may be slowly ramped up. When transition from the dual phase to the single phase operation, the output voltage may be elevated while slowing ramping down the slave phase current. The boost converter may include a current detection circuit for adjusting the peak current of each phase to balance the average current levels. The boost converter may also include an in-rush current controller configured to sense a short fault.

公开(公告)号：US11798462B2

公开(公告)日：2023-10-24

申请号：US17507717

申请日：2021-10-21

Applicant: APPLE INC.

Inventor： Mohammad J. Navabi-Shirazi ,  Ming Gu ,  Alejandro Lara Ascorra ,  James E. Brown

IPC: G09G3/32 ,  G09G5/10

CPC classification number: G09G3/32 ,  G09G5/10 ,  G09G2320/064 ,  G09G2360/142 ,  G09G2360/147

Abstract: Light emitting diode display panels with an open loop amplifier resulting in better brightness accuracy and matching between multiple light emitting diode strings.

公开(公告)号：US20230085621A1

公开(公告)日：2023-03-23

申请号：US17853247

申请日：2022-06-29

Applicant: Apple Inc.

Inventor： Behzad Mohtashemi ,  Asif Hussain ,  Feng Guo ,  Jingdong Chen ,  Ming Gu ,  Mohammad J. Navabi-Shirazi ,  Omar Alnaggar ,  Venkataraman V. Iyer ,  Yang Zhang

IPC: G09G3/20

Abstract: A display device include a first light emitting diode (LED), a second LED, and at least one processor of a driver. The processor drives the first LED and the second LED. The processor determines a first pulse width associated with the first LED and a second pulse width associated with the second LED based on a level of brightness to be emitted by the first LED and the second LED. The processor also receives a gap clock and determines a first pulse start time and a first pulse end time for the first LED based on the first pulse width. Moreover, the processor determines a second pulse start time and a second pulse end time for the second LED based on the first pulse end time, the second pulse width, and/or the gap clock, in which the first pulse end time and the second pulse end time are different.

公开(公告)号：US20220130327A1

公开(公告)日：2022-04-28

申请号：US17507717

申请日：2021-10-21

Applicant: APPLE INC.

Inventor： Mohammad J. Navabi-Shirazi ,  Ming Gu ,  Alejandro Lara Ascorra ,  James E. Brown

IPC: G09G3/32 ,  G09G5/10

Abstract: Light emitting diode display panels with an open loop amplifier resulting in better brightness accuracy and matching between multiple light emitting diode strings.

公开(公告)号：US11823612B2

公开(公告)日：2023-11-21

申请号：US17853247

申请日：2022-06-29

Applicant: Apple Inc.

Inventor： Behzad Mohtashemi ,  Asif Hussain ,  Feng Guo ,  Jingdong Chen ,  Ming Gu ,  Mohammad J Navabi-Shirazi ,  Omar Alnaggar ,  Venkataraman V Iyer ,  Yang Zhang

IPC: G09G3/20

CPC classification number: G09G3/2092 ,  G09G2310/0264 ,  G09G2310/08

Abstract: A display device include a first light emitting diode (LED), a second LED, and at least one processor of a driver. The processor drives the first LED and the second LED. The processor determines a first pulse width associated with the first LED and a second pulse width associated with the second LED based on a level of brightness to be emitted by the first LED and the second LED. The processor also receives a gap clock and determines a first pulse start time and a first pulse end time for the first LED based on the first pulse width. Moreover, the processor determines a second pulse start time and a second pulse end time for the second LED based on the first pulse end time, the second pulse width, and/or the gap clock, in which the first pulse end time and the second pulse end time are different.

公开(公告)号：US20230100812A1

公开(公告)日：2023-03-30

申请号：US17870576

申请日：2022-07-21

Applicant: Apple Inc.

Inventor： Behzad Mohtashemi ,  Mohammad J Navabi-Shirazi ,  Feng Guo ,  Omar Alnaggar ,  Venkataraman V Iyer ,  Jingdong Chen ,  Yang Zhang ,  Ming Gu ,  Asif Hussain

IPC: G09G3/34

Abstract: Systems and methods for preserving a pulse width modulation (PWM) resolution while increasing the frequency of a pulse width modulation (PWM) clock are provided. An electronic display backlight system may include a backlight element and backlight dimming circuitry. The backlight element may be driven according to a pulse width modulation (PWM) signal over a PWM clock cycle equal to a multiple M of a baseline PWM clock frequency associated with a baseline PWM resolution. The backlight dimming circuitry may receive a brightness code of the baseline PWM resolution and generate the PWM signal at least in part by dividing the brightness code by M.

公开(公告)号：US20220061135A1

公开(公告)日：2022-02-24

申请号：US17238851

申请日：2021-04-23

Applicant: Apple Inc.

Inventor： Ming Gu ,  Yanhui Xie ,  Jingdong Chen ,  Asif Hussain ,  Behzad Mohtashemi ,  Mohammad Jafar Navabi-Shirazi ,  Linda A. Kamas ,  Alejandro Lara Ascorra

IPC: H05B45/14 ,  H05B45/325 ,  G09G3/34

Abstract: Aspects of the subject technology relate to electronic devices having a display. The display includes a channel of light emitting diodes (LEDs) having controllable brightness levels and control circuitry coupled to the channel of LEDs. The control circuitry provides a pulse width modulated (PWM) signal having a duty cycle to control the brightness levels. An adaptive headroom control circuitry is configured to sense a headroom voltage signal for the channel of LEDs and apply a first time period for blanking the headroom voltage signal during the first time period that is associated with a settling time for the headroom voltage signal.

公开(公告)号：US11694641B2

公开(公告)日：2023-07-04

申请号：US17870576

申请日：2022-07-21

Applicant: Apple Inc.

Inventor： Behzad Mohtashemi ,  Mohammad J Navabi-Shirazi ,  Feng Guo ,  Omar Alnaggar ,  Venkataraman V Iyer ,  Jingdong Chen ,  Yang Zhang ,  Ming Gu ,  Asif Hussain

IPC: G09G3/34

CPC classification number: G09G3/3406 ,  G09G2310/08 ,  G09G2320/064

Abstract: Systems and methods for preserving a pulse width modulation (PWM) resolution while increasing the frequency of a pulse width modulation (PWM) clock are provided. An electronic display backlight system may include a backlight element and backlight dimming circuitry. The backlight element may be driven according to a pulse width modulation (PWM) signal over a PWM clock cycle equal to a multiple M of a baseline PWM clock frequency associated with a baseline PWM resolution. The backlight dimming circuitry may receive a brightness code of the baseline PWM resolution and generate the PWM signal at least in part by dividing the brightness code by M.

公开(公告)号：US10714028B2

公开(公告)日：2020-07-14

申请号：US16418882

申请日：2019-05-21

Applicant: Apple Inc.

Inventor： Jingdong Chen ,  Asif Hussain ,  Mohammad J. Navabi-Shirazi ,  Behzad Mohtashemi ,  Yanhui Xie ,  Jy Ryoo ,  Ming Gu

IPC: H02J1/10 ,  H02M1/00 ,  G09G3/34 ,  G09G3/32 ,  F21S4/20

Abstract: A display may have an array of pixels illuminated using a backlight unit. The backlight unit may include multiple strings of light-emitting diodes (LEDs) and a boost converter for providing an output voltage to the multiple LED strings. The boost converter may have a single-phase single-switch, single-phase multi-switch, and/or multi-phase multi-switch configuration, where the switches are turned off when the peak current is reached. When transitioning from a single phase to a dual phase operation, the second (slave) phase current may be slowly ramped up. When transition from the dual phase to the single phase operation, the output voltage may be elevated while slowing ramping down the slave phase current. The boost converter may include a current detection circuit for adjusting the peak current of each phase to balance the average current levels. The boost converter may also include an in-rush current controller configured to sense a short fault.