Lens Array Illumination System for Uniform Projection

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Solution Overview

Problem

Image blur occurs when segmental light fluxes from an optical integrator are superimposed and focused on an illuminated area due to misalignment of illuminant images with the optical axes of the second lens array, leading to non-uniform illumination and reduced image quality in projection-type display apparatuses.

Innovation Solution

The illumination system includes a first lens array dividing the light flux into segmental fluxes, a second lens array with lens elements aligned in the same direction as the first lens array, and a superimposing lens to precisely focus the segmental fluxes on the illuminated area, ensuring alignment and uniform illumination, even with multiple illuminants or concave mirrors, thereby preventing image blur.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If multiple illuminants are used to increase brightness, then illumination intensity is improved, but image blur occurs due to misalignment of illuminant images with optical axes

Engineering Contradiction:

ImprovebrightnessVSAvoidimage focus precision

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent divides the second lens array into multiple sub-lens arrays, each corresponding to a specific illuminant. This segmentation allows each sub-array to independently handle light from its corresponding illuminant, ensuring that illuminant images are properly aligned with the optical axes of the respective sub-lenses, thereby preventing image blur while maintaining high brightness

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different optical configurations to different regions of the second lens array. Specifically, sub-lens arrays corresponding to off-axis illuminants are positioned and oriented to receive light at appropriate angles, creating local optical paths that ensure proper image formation for each illuminant region while maintaining overall system brightness

Inventive Principle:

Principle #3Local quality

2Area of stationary object

If segmental light fluxes are superimposed without proper alignment, then illumination area is covered, but image blur occurs due to misalignment

Engineering Contradiction:

Improveilluminated area coverageVSAvoidsuperimposition accuracy

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

The patent introduces angular and positional dimensions to the superimposition process by orienting sub-lens arrays at specific angles and positions. This multi-dimensional arrangement ensures that segmental light fluxes from multiple illuminants are superimposed with high precision on the illuminated area, preventing blur while maintaining comprehensive coverage

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 ensures precise superimposition and focusing of segmental light fluxes, reducing or eliminating image blur and enhancing the uniformity of illumination, which increases the brightness and clarity of projected images while reducing the need for excessive illumination.

Implementation Method 1

a first lens array that is an optical component having a plurality of first small lenses arranged therein, the first small lenses dividing the illumination light flux emitted from the light source into a plurality of segmental light fluxes

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

a second lens array that is an optical component having a plurality of second small lenses arranged therein, the second small lenses corresponding to the respective plurality of first small lenses and receiving the incident segmental light fluxes having exited from the plurality of first small lenses

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 3

a superimposing lens that superimposes the segmental light fluxes having exited from the plurality of second small lenses on the illuminated area

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS9454069B2Illumination system having first and second lens arrays including plano-convex lenses wherein some lenses in the second array include a first and a second lens element, projection-type display apparatus, and optical integrator

Publication Date: 2016.09.27 SEIKO EPSON CORP

AI summary

In at least one embodiment of the disclosure, an illumination system includes a light source that emits an illumination light flux. A first lens array has a plurality of first small lenses arranged therein. The first small lenses divide the illumination light flux emitted from the light source into a plurality of segmental light fluxes. A second lens array has a plurality of second small lenses arranged therein. The second small lenses have a one-to-one correspondence with the first small lenses and are configured to receive the segmental light fluxes exiting from the first small lenses. At least some of the second small lenses each include a plurality of lens elements disposed in a surface direction that is the same as the second small lenses. A superimposing lens superimposes on an illuminated area the segmental light fluxes exiting from the plurality of second small lenses.