Under-Display Camera Pixel Circuit Layout for UDC Uniformity

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Solution Overview

Problem

Electronic devices with under-display cameras face challenges in increasing transmittance and reducing luminance and lifespan differences between pixels in the UDC area and normal areas, leading to visibility issues.

Innovation Solution

The structure of first pixels in the UDC area and the driving circuit are modified, with a first driving TFT having a straight channel shape and a larger channel width than the second TFT, which has a curved shape and shorter channel length, to enhance transmittance and reduce luminance and lifespan differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the arrangement density of pixels in the UDC area is lowered to increase transmittance, then the amount of light introduced into the camera is improved, but the luminance difference between the UDC area and normal area increases

Engineering Contradiction:
Improvelight transmittanceVSAvoidluminance uniformity
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by configuring pixels in the UDC area with different characteristics from normal area pixels. Specifically, the UDC area pixels have reduced emission intensity and modified structural parameters (such as electrode dimensions and organic layer thickness) to compensate for the lower arrangement density, ensuring that each pixel in the UDC area emits appropriate luminance to match the overall display uniformity despite the reduced pixel count.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If the arrangement density of pixels in the UDC area is lowered to increase transmittance, then the camera visibility is improved, but the lifespan difference between pixels in the UDC area and normal area increases

Engineering Contradiction:
Improvelight transmittanceVSAvoidpixel lifespan uniformity
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent addresses lifespan uniformity by applying local quality principles to the pixel structure in the UDC area. The modified pixel configuration (including adjusted electrode areas, organic layer thickness, and emission intensity parameters) distributes the operational stress more evenly, compensating for the reduced pixel density and ensuring that pixels in the UDC area have comparable lifespan characteristics to those in the normal area.

Inventive Principle:
Principle #3Local quality

3Illumination intensity

If the pixel arrangement density is reduced in the UDC area, then the transmittance is increased, but the visibility problem of the UDC area increases

Engineering Contradiction:
Improvelight transmittanceVSAvoidUDC area visibility
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent employs color changes principle by adjusting the emission characteristics of pixels in the UDC area. The modified pixel structure alters the luminance output and potentially the spectral distribution, allowing the UDC area pixels to blend more effectively with the surrounding normal area pixels, thereby reducing the visual detectability of the camera region while maintaining adequate light transmission.

Inventive Principle:
Principle #32Color changes

Data Source

PatentEP4482279B1Electronic device comprising udc
Publication Date: 2026.03.25 SAMSUNG ELECTRONICS CO LTD
  • EP4482279B1 patent drawingFigure 1
  • EP4482279B1 patent drawingFigure 2
  • EP4482279B1 patent drawingFigure 3

AI summary

An embodiment of the present disclosure relates to an electronic device comprising an under display camera (UDC), comprising: a camera which is arranged to overlap part of a display inside a housing, and obtains light that has passed through the display from the outside, wherein the display comprises: a first region in which a first pixel overlapping at least part of the camera and a first pixel driving unit for driving the first pixel are arranged; and a second region which is the remaining region excluding the first region and in which a second pixel and a second pixel driving circuit for driving the second pixel are arranged, the first pixel driving circuit comprises a first driving TFT comprising a first channel region having a straight line shape that does not comprise a curved line shape, the second pixel driving circuit comprises a second driving TFT comprising a second channel region comprising a curved line shape, a first channel width of the first driving TFT is greater than a second channel width of the second driving TFT, and a first channel length of the first driving TFT may be less than a second channel length of the second driving TFT. The present disclosure may further comprise various other embodiments.