Backlight noise reduction systems and methods for electronic device displays
AssigneeApple Inc.
InventorsVehbi Calayir, James E. Brown
Life of this patent
Estimating the term…
Abstract
Aspects of the subject technology relate to control circuitry for light-emitting diodes (LEDs). The control circuitry may include an LED timing controller integrated circuit configured to operate groups of rows of the LEDs with a common randomized row order that mitigates acoustic noise. The LEDs may be implemented in a backlight of a liquid crystal display and the common randomized row order that mitigates acoustic noise may be generated and/or executed to synchronize the LED operation with the operation of the pixels of the liquid crystal display.
Claims20
An electronic device, comprising:
- a display with a liquid crystal display unit and a backlight unit, the backlight unit comprising an array of light-emitting diodes arranged in rows and columns, the rows arranged in groups of adjacent rows;
- and
- control circuitry configured to:
- identify a plurality of pseudo-randomized row orders for operation of the rows of each group of adjacent rows, wherein each row order synchronizes the operation of the rows of the array of light-emitting diodes of the backlight unit with operation of the liquid crystal display unit;
- pseudo-randomly select one of the identified plurality of pseudo-randomized row orders;
- and
- operate, concurrently, the rows of each group including a row of a first group and a corresponding row of a second group using the selected one of the identified plurality of pseudo-randomized row orders.
An electronic device, comprising:
- a display with a liquid crystal display unit and a backlight unit, the backlight unit comprising an array of light-emitting diodes arranged in rows and columns, the rows arranged in groups of adjacent rows;
- and
- control circuitry configured to:
- identify a backlight scan rate at which to operate the array of light-emitting diodes, the backlight scan rate being an integer multiple of a liquid crystal display (LCD) scan rate for the LCD unit, the integer multiple of the LCD scan rate based on at least one of a number of rows and a number of groups of the array of light-emitting diodes;
- identify a pseudo-random row order for operation of the rows of each of the groups of adjacent rows;
- and
- operate, concurrently, the rows of each group including a row of a first group and a corresponding row of a second group using the pseudo-random row order at the identified backlight scan rate, wherein synchronization of the LCD unit with the array of light-emitting diodes of the backlight unit operating in the pseudo-random row order is preserved using the identified backlight scan rate.
A method, comprising:
- identifying, for multiple groups of adjacent rows of light-emitting diodes in an array of light-emitting diodes in a backlight of a display of an electronic device, a plurality of pseudo-randomized row orders for operation of the rows of each group of adjacent rows, wherein each row order synchronizes the operation of the rows of the array of light-emitting diodes of the backlight unit with operation of a liquid crystal display unit of the display;
- pseudo-randomly selecting one of the identified plurality of pseudo-randomized row orders;
- and
- operating, concurrently, the rows of each group including a row of a first group and a corresponding row of a second group using the selected one of the identified plurality of pseudo-randomized row orders.
Dependencies are inferred from the claim text.