Oculus Patent | Redundant microleds of multiple rows for compensation of defective microled

Patent: Redundant microleds of multiple rows for compensation of defective microled

Publication Number: 20190019448

Publication Date: 2019-01-17

Applicants: Oculus

Abstract

Multiple rows of light sources emitting the same color are arranged to provide redundancy against defective light sources. The light sources are used in conjunction with an optical element to display on a screen. Although only a single row of light sources is needed for each color, multiple rows of light sources are provided for each color and the optical element scans vertically across rows to produce an image. When a defective light source is detected, light sources surrounding the defective light source are overdriven to compensate for the defective light source.

Background

This disclosure generally relates to operating light sources to generate images on a screen, and specifically relates to providing redundancy by having more than one rows of light sources.

Light sources may be implemented as one or more rows of microscopic light emitting diodes (microLEDs) that can emit light of a certain color. Generally, microLEDs are formed by processing GaN or GaAs substrates, and tends to have higher total brightness than organic light emitting diode (OLED). Based on the processing of GaN or GaAs substrates, the fabricated microLEDs emit light of different colors. Hence, combinations of microLEDs to form pixels capable of displaying multiple colors.

The process of fabricating microLEDs is complicated and the yield of operable microLEDs may be lower than desired. Hence, one or more microLEDs on asemiconductor backplane may be inoperable or defective, and not emit light.

Summary

Embodiments of the present disclosure relate to compensating loss of brightness from a light source in an array of light sources by increasing brightness of other light sources. First brightness of light sources in the array of light sources corresponding to the image signal is determined. The first brightness of light sources to second brightness of light sources is adjusted to compensate for a defective light source in the array of light sources. Adjusting the first brightness of light sources to the second brightness of light sources includes increasing the brightness of at least a subset of functioning light sources in a same column as the defective light source, and increasing the brightness of at least a subset of functioning light sources in a same row as the defective light source. The optical element is operated to sequentially reflect light from different rows of the light sources in the array of light sources according to the second brightness onto the scan field.