Facebook Patent | Measurement of display characteristics of electronic display panel using optical tapers

Patent: Measurement of display characteristics of electronic display panel using optical tapers

Publication Number: 10161791

Publication Date: 2018-12-25

Applicants: Facebook

Abstract

An apparatus for measuring characteristics of an electronic display panel includes an array of optical elements. Each optical element has a first surface and a second surface. The first surface faces the electronic display panel and receives light from pixels of the electronic display panel. The second surface faces away from the electronic display panel and has an area smaller than the area of the first surface. The second surface emits a combined version of the light received by the first surface. The apparatus further includes a light sensor facing the second surface to measure one or more parameters of the emitted light.

Background

The present disclosure generally relates to electronic display panels, and specifically to measuring display characteristics of such electronic display panels. These spatial non-uniformities reduce user experience and immersion in a VR environment.

An electronic display panel includes a display surface having pixels that display a portion of an image by emitting one or more wavelengths of light from one or more sub-pixels. During the manufacturing process, various factors cause non-uniformities in luminance, radiance, or chrominance of light emitted by pixels and sub-pixels. For example, variations in flatness of a carrier substrate, variations in a lithography light source, temperature variations across the substrate, or mask defects may result in the electronic display panel having transistors with non-uniform emission characteristics. As a result, different sub-pixels driven with the same voltage and current will emit different intensities of light (also referred to as brightness). Variations that are a function of position on the electronic display panel cause different display regions of the electronic display panel to have different luminance, radiance, or chrominance. If these errors systematically affect sub-pixels of one color more than sub-pixels of another color, then the electronic display panel has non-uniform color balance as well. These spatial non-uniformities of luminance, radiance, and chrominance decrease image quality and limit applications of the electronic display panel. For example, virtual reality (VR) systems typically include an electronic display panel that presents virtual reality images. These spatial non-uniformities reduce user experience and immersion in a VR environment.

Summary

Embodiments relate to measuring characteristics of an electronic display panel. A measuring apparatus includes an array of optical elements. Each optical element includes a first surface facing the electronic display panel to receive light from pixels of the electronic display panel. Each optical element further includes a second surface facing away from the electronic display panel to emit a combined version of the light received by the first surface. The area of the second surface is smaller than the area of the first surface. The apparatus further includes light sensors facing the second surface of each of the optical elements to measure parameters of the emitted light.