Light Source Device for Projectors Using Wavelength-Selective Switching

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Solution Overview

Problem

Existing projector systems face challenges in achieving appropriate color balance due to the inability to effectively switch and control the emission of colored light beams, leading to inconsistent image quality.

Innovation Solution

A light source device that emits multiple colored light beams with adjustable switching capabilities using a combination of partial reflection and wavelength-selective elements, allowing for the control of light beam emission modes to optimize color balance and luminance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If multiple colored light beams are emitted simultaneously to increase luminance, then the luminance of the projected image is improved, but the color balance becomes inappropriate and inconsistent

Engineering Contradiction:

ImproveluminanceVSAvoidcolor balance

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent applies dynamics by enabling the light source device to switch between different emission modes (first through fifth modes) depending on the required image characteristics. The system dynamically adjusts which colored light beams are emitted and in what proportions, allowing optimal color balance for different scenarios while maintaining high luminance when needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes parameters by controlling the emission proportions of different colored light beams (red, green, blue, and yellow) through the outgoing light switching device. By adjusting these parameters, the system achieves appropriate color balance while maintaining sufficient luminance output.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If a fixed light emission configuration is used, then the device structure is simple, but the adaptability to different image requirements is reduced

Engineering Contradiction:

Improvelight emission controlVSAvoidimage quality adaptation

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies universality by designing the light source device to perform multiple functions through a single integrated structure. The outgoing light switching device enables the system to adapt to different image requirements (color balance, luminance, color gamut) without requiring separate light sources or complex switching mechanisms, making the device versatile for various projection scenarios.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Illumination intensity

If the outgoing light switching device emits the whole mixed light beam, then the luminance is maximized, but the color balance cannot be adjusted for specific wavelengths

Engineering Contradiction:

ImproveluminanceVSAvoidwavelength selection

Core Design Contradiction:

Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent applies segmentation by dividing the mixed light beam into separate wavelength components (red, green, blue, and yellow light beams) and enabling independent control of each component through the outgoing light switching device. This allows the system to maximize luminance by emitting the whole mixed beam when needed, while also selecting specific wavelength ranges when color balance adjustment is required.

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

Enables precise control over the emission of colored light beams, improving color balance and luminance consistency in projected images by allowing for switching between different light beam configurations.

Implementation Method 1

the outgoing light switching device includes a partial reflection element, the partial reflection element reflects a part of the mixed light beam entering the partial reflection element

Methodology Applied

Scientific EffectPartial reflection: Reflection

Implementation Method 2

the outgoing light switching device includes a wavelength-selective reflection element, the wavelength-selective reflection element transmits one colored light beam out of colored light beams and reflects the other colored light beam

Methodology Applied

Scientific EffectWavelength-selective reflection: Dichroic Filter

Data Source

PatentUS10996551B2Light source device, illumination optical device, and projector

Publication Date: 2021.05.04 SEIKO EPSON CORP

AI summary

A light source device configured to emit a light beam in a first direction emits a first colored light beam from a first exit position, a second colored light beam longer in wavelength than the first colored light beam, a third colored light beam shorter in wavelength than the first colored light beam, and a fourth colored light beam, a mixed light beam including the first colored light beam and the second colored light beam enters an outgoing light switching device disposed in a light path of the fourth colored light beam.