Phosphor Holder Alignment for Projection Display Stability

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Solution Overview

Problem

The intensity and hue of output light in projection type display devices fluctuate due to the non-perpendicular arrangement of the phosphor formation surface relative to the incident excitation light, leading to unstable fluorescence emission.

Innovation Solution

A phosphor holder with a pedestal, motor, and adjustment shims is used to ensure the phosphor wheel's formation surface is perpendicular to the excitation light, with the motor rotating the phosphor wheel and shims adjusting its position to maintain alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the fluorescent unit is positioned closer to the light condensing element to increase fluorescence output, then the amount of fluorescence reaching the light condensing element increases, but the fluorescent unit may contact or interfere with the light condensing element

Engineering Contradiction:

Improvefluorescence output intensityVSAvoidcontact interference between fluorescent unit and light condensing element

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

A guide member is introduced as an intermediary component between the fluorescent unit and the light condensing element. The guide member includes a guide surface that guides the fluorescent unit to the third position (closest to light condensing element) while a restriction surface prevents contact with the light condensing element, thus resolving the contradiction between maximizing fluorescence output and preventing harmful contact interference

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the formation surface on which phosphor is formed is not perpendicular to the incident excitation light, then the emission direction of generated fluorescence varies, but this causes fluctuation in output light intensity and hue

Engineering Contradiction:

Improveease of phosphor wheel assemblyVSAvoidstability of output light intensity and hue

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The phosphor holder is designed with a predetermined structure that preliminarily positions the phosphor wheel such that the formation surface becomes perpendicular to the incident excitation light. This preliminary arrangement ensures stable fluorescence emission and consistent output light characteristics without requiring complex adjustment mechanisms during operation

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If a guide member with multiple guide parts is used to position the fluorescent unit at multiple positions, then positioning flexibility is improved, but the device complexity increases

Engineering Contradiction:

Improvepositioning flexibility of fluorescent unitVSAvoidcomplexity of guide member structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The guide member is segmented into distinct functional parts: a guide surface for positioning the fluorescent unit at the third position, and a restriction surface for preventing contact with the light condensing element. This segmentation allows each part to perform its specific function efficiently, providing positioning flexibility while keeping the overall structure relatively simple and manageable

Inventive Principle:

Principle #1Segmentation

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 stabilizes the intensity and hue of the output light by ensuring the phosphor surface is perpendicular to the excitation light, preventing fluctuations in fluorescence emission and maintaining consistent image quality.

Implementation Method 1

Fluorescence is generated by irradiating a phosphor formed on a phosphor wheel with laser light as excitation light

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Implementation Method 2

a motor that is mounted on the base and that has a rotating shaft substantially orthogonal to an in-plane direction of the pedestal; a phosphor wheel on which a phosphor is formed and that is rotated by the motor

Methodology Applied

Scientific EffectMechanical rotation:

Data Source

PatentUS10634980B2Phosphor holder, light source device, and projection type display device including light source device

Publication Date: 2020.04.28 SHARP KK

AI summary

A phosphor holder includes: a rectangular flat plate-like pedestal; a plurality of phosphor holder attachment surfaces provided at a plurality of points, respectively, on an outer peripheral section of the pedestal and protruding in a first direction by a predetermined height with respect to surroundings; a base mounted substantially in a center of a surface of the pedestal facing in the first direction; a motor mounted on the base and having a rotating shaft substantially orthogonal to an in-plane direction of the pedestal; a phosphor wheel on which a phosphor is formed and that is rotated by the motor; and a plurality of adjustment shims mounted on the plurality of phosphor wheel attachment surfaces and brought into contact with the holder attachment surface.