Display Element Microlens Shift for Wide Angle Luminance

Solution Overview

Problem

Existing image display apparatuses, such as head mount displays, face challenges in maintaining image quality at wide angles of view due to increased exit angles of light from the peripheral areas of display elements, leading to luminance decreases and chromaticity shifts.

Innovation Solution

The image display apparatus incorporates right-eye and left-eye display elements with color filters and microlenses shifted relative to the pixels, particularly in the peripheral areas, to align with the exit angles of image light, thereby improving the angle-of-field characteristic.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the focal length of the optical system is reduced to achieve a wider angle of view and reduced thickness, then the angle of view and compactness are improved, but the exit angle of light from the peripheral area increases causing luminance decrease and chromaticity shift

Engineering Contradiction:

Improveangle of viewVSAvoidluminance in peripheral area

Core Design Contradiction:

Area of stationary objectVSIllumination intensity

Solution Approach 1:

The patent applies local quality by differentiating the configuration of optical elements between the central and peripheral areas of the display element. Specifically, the microlens and color filter are positioned at different locations relative to the pixel in the peripheral area compared to the central area, optimizing light extraction and color accuracy locally where the exit angle is larger, thereby resolving the luminance and chromaticity degradation in peripheral regions while maintaining the reduced focal length design

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs parameter changes by adjusting the positional parameters of the microlens and color filter relative to the pixel in different regions of the display element. By changing the offset distance between these optical elements and the pixel center based on the radial position, the system compensates for the increased exit angle in peripheral areas, maintaining consistent luminance and chromaticity across the entire field of view despite the reduced focal length

Inventive Principle:

Principle #35Parameter changes

2Area of stationary object

If the focal length of the optical system is reduced to achieve a wider angle of view and reduced thickness, then the angle of view and compactness are improved, but the chromaticity accuracy in the peripheral area deteriorates

Engineering Contradiction:

Improveangle of viewVSAvoidchromaticity accuracy in peripheral area

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

The patent applies local quality by differentiating the configuration of optical elements between the central and peripheral areas of the display element. Specifically, the microlens and color filter are positioned at different locations relative to the pixel in the peripheral area compared to the central area, optimizing light extraction and color accuracy locally where the exit angle is larger, thereby resolving the luminance and chromaticity degradation in peripheral regions while maintaining the reduced focal length design

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs parameter changes by adjusting the positional parameters of the microlens and color filter relative to the pixel in different regions of the display element. By changing the offset distance between these optical elements and the pixel center based on the radial position, the system compensates for the increased exit angle in peripheral areas, maintaining consistent luminance and chromaticity across the entire field of view despite the reduced focal length

Inventive Principle:

Principle #35Parameter changes

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

This configuration enhances luminance and reduces chromaticity shifts in the peripheral areas, allowing for wider and more natural image observation without compromising image quality.

Implementation Method 1

Each of the right-eye display element and the left-eye display element includes an element that is at least one of a color filter and a microlens provided corresponding to each of the plurality of pixels

Methodology Applied

Scientific EffectLens focusing: Lens

Implementation Method 2

Each of the right-eye display element and the left-eye display element includes an element that is at least one of a color filter and a microlens provided corresponding to each of the plurality of pixels

Methodology Applied

Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentUS20250044596A1Image display apparatus

Publication Date: 2025.02.06 CANON KK

AI summary

An image display apparatus includes right-eye and left-eye display elements, each of which has a plurality of pixels on a display surface, and right-eye and left-eye display optical system configured to guide image light from the right-eye and left-eye display element to right and left eyes of an observer. Each of the right-eye and left-eye display elements includes an element that is at least one of a color filter and a microlens provided corresponding to each pixel. An intersection of an optical axis of each of the right-eye and left-eye display optical systems and the display surface shifts from a center of the display surface. In each of the right-eye and left-eye display elements, a shift amount of a center of the element from a center of the pixel in a peripheral area is larger than that in an intersection area.