Display Device Light Sensor Positioning for Ambient Light Calibration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional display devices fail to accurately measure and adjust display characteristics in consideration of both the display panel and ambient light, leading to suboptimal image rendering in various usage environments.

Innovation Solution

A display device with a light sensor positioned outside the screen and within a recessed framing member, tilted to receive outgoing light and reflected ambient light, while shielding extraneous light to prevent interference, allowing for precise measurement and adjustment of display characteristics without obstructing the screen.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a light sensor is provided inside the display device to measure backlight characteristics, then the measurement can be performed automatically, but the sensor cannot measure the display characteristics of the liquid crystal panel and ambient light reflection

Engineering Contradiction:
Improveautomatic calibrationVSAvoiddisplay characteristics measurement accuracy
Core Design Contradiction:
Extent of automationVSMeasurement precision

Solution Approach 1:

A reflective member is introduced as an intermediary component. This reflective member reflects light from the backlight through the liquid crystal panel and directs it to the light sensor, enabling the sensor to indirectly measure the display characteristics including ambient light reflection effects while remaining positioned inside the display device for automatic operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a separate light sensor is used to measure display characteristics, then both backlight and liquid crystal panel characteristics can be measured, but the user must manually install the sensor which takes time and prevents device usage during measurement

Engineering Contradiction:
Improvedisplay characteristics measurement accuracyVSAvoiduser convenience
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The light sensor that was previously a separate external component is merged with the display device structure. The sensor is integrated into the housing and positioned to work with the reflective member, eliminating the need for manual installation while maintaining the capability to measure both backlight and liquid crystal panel characteristics along with ambient light reflection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The measurement system is pre-configured during manufacturing with the light sensor and reflective member positioned to enable automatic measurement. This preliminary setup allows the device to perform self-calibration without requiring user intervention during the measurement process, thus maintaining user convenience.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If a movable light sensor (swing sensor) is used, then the sensor can cover only the peripheral part of the screen during measurement, but the structure becomes more complex with motors or actuators

Engineering Contradiction:
Improvedisplay characteristics measurement accuracyVSAvoidsensor mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The complexity of the movable sensor mechanism (motors, actuators, swing joints) is extracted and removed from the system. Instead of making the sensor movable, the solution extracts the need for movement by using a fixed sensor position combined with a reflective member that directs the appropriate light paths to the sensor, achieving measurement accuracy without mechanical complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

4Adaptability or versatility

If the light sensor is positioned to measure reflected ambient light, then the measurement considers usage environment, but direct extraneous light may interfere with the measurement accuracy

Engineering Contradiction:
Improveenvironmental adaptationVSAvoidmeasurement accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The light sensor is positioned with specific local geometric characteristics - it is arranged to receive light reflected from specific regions of the display panel while its orientation and positioning create a selective field of view. This local quality control allows the sensor to measure ambient light reflection from the display while excluding direct extraneous light sources, maintaining both environmental adaptability and measurement accuracy.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables accurate measurement and adjustment of display characteristics based on both the display panel and ambient light, enhancing display quality and user convenience by eliminating the need for manual sensor placement and reducing interference from direct extraneous light.

Implementation Method 1

a light sensor provided outside a screen of a display panel... allowing outgoing light from the screen of the display panel and extraneous light reflected on the screen to enter the light sensor

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2472496B1Display device
Publication Date: 2019.11.13 EIZO CORP
  • EP2472496B1 patent drawingFigure 1
  • EP2472496B1 patent drawingFigure 2(a)~2(b)
  • EP2472496B1 patent drawingFigure 3

AI summary

The present invention relates to a display device that measures display characteristics (such as luminance or chromaticity) associated with a display panel. The display device of the present invention has a light sensor (5) provided at a position allowing outgoing light from a screen (1a) of a liquid crystal panel (1), which serves as the display panel, and extraneous light reflected on the screen (1a) to enter the light sensor (5). Since the light sensor (5) is provided at the position, it is possible to measure the characteristics of the display panel and also the characteristics of the extraneous ambient light reflected on the screen. Thus, it is possible to accurately adjust the display characteristics based on the measurement results.