Compact Projector Using Dual Diffraction Elements for Angular Compensation
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Solution Overview
Problem
Existing compact projectors using holograms for image projection are not adequately reduced in size to be incorporated into other devices while maintaining high-definition image formation and power efficiency.
Innovation Solution
A projector design incorporating a self-luminous display element with multicolored image light and a pair of diffraction elements, where the first diffraction element diffracts the light and the second element compensates for angular separation by wavelength, allowing for compact size and high-definition image projection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a rear projection type display apparatus uses a hologram to reduce thickness, then the apparatus forms a thin television, but the overall size is not sufficiently reduced to be incorporated into another device
Solution Approach 1:
The patent divides the projection system into two separate diffraction elements (first and second diffraction elements) with distinct functions. The first diffraction element diffracts image light while the second diffraction element performs angular compensation. This segmentation allows each element to be optimized for its specific function, enabling compact integration while maintaining overall system performance and reducing total apparatus size.
Solution Approach 2:
The patent transitions from a single thick holographic element to a multi-layer diffraction element structure arranged in the optical path direction. By distributing diffraction functions across multiple thin layers rather than using one thick element, the system achieves both thickness reduction and overall size minimization while maintaining high-definition image formation capability.
2Length of stationary object
If a compact projector uses hologram to reduce size, then thickness is reduced, but high-definition image formation and power efficiency are not adequately maintained
Solution Approach 1:
By separating the diffraction function into two distinct elements (first for image light diffraction, second for angular compensation), the patent achieves high-definition image formation through precise functional division. Each element can be optimized for its specific diffraction angle requirements, ensuring accurate light control and sharp image quality even in a compact form factor.
Solution Approach 2:
The patent optimizes diffraction angles for each wavelength band (red, green, blue) separately in the two diffraction elements. By adjusting and compensating diffraction angles for different colors, the system maintains high-definition image formation across the entire visible spectrum while keeping the projector compact.
3Length of stationary object
If a rear projection type display apparatus uses a hologram, then thickness is reduced, but power consumption is not sufficiently optimized for high-brightness projection
Solution Approach 1:
The patent replaces traditional mechanical projection systems with a holographic diffraction-based system. By using optical diffraction through two specialized elements instead of mechanical light steering or large projection lenses, the system achieves high-brightness projection with significantly reduced power consumption and compact thickness.
Solution Approach 2:
The patent optimizes the diffraction characteristics of both elements to maximize light efficiency and minimize energy loss. By precisely controlling diffraction angles and efficiency for each wavelength band, the system achieves high-brightness image projection while maintaining low power consumption in a thin form factor.
4Device complexity
If angular separation of image light by wavelength is not compensated, then device complexity is reduced, but image quality deteriorates due to color separation
Solution Approach 1:
The patent segments the diffraction function into two specialized elements: the first diffraction element for initial light diffraction and the second diffraction element for angular compensation. This segmentation enables effective correction of wavelength-dependent angular separation without requiring complex additional optical components, maintaining both simplicity and high-definition image quality.
Solution Approach 2:
The second diffraction element acts as an intermediary that compensates for the angular separation introduced by the first diffraction element. By positioning this compensation element in the optical path, the system corrects color separation effects and achieves high-definition full-color image formation with a relatively simple overall structure.
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
The solution enables a very thin and compact projector that can be integrated into devices like smartphones or eyeglasses, achieving high-brightness image projection with reduced power consumption and high-definition image formation.
Implementation Method 1
a first diffraction element configured to diffract the image light from the display element
Implementation Method 2
a second diffraction element configured to emit the image light while making angular compensation for angular separation of the image light occurring depending on the wavelength band of each color of light when diffracted by the first diffraction element, by diffracting the image light
Data Source
AI summary
A projector includes a self-luminous display element configured to emit image light that is multicolored and has a predetermined wavelength band for each color of light, a first diffraction element configured to diffract the image light from the display element, and a second diffraction element configured to emit the image light while making angular compensation, by diffracting the image light, for angular separation of the image light occurring depending on the wavelength band of each color of light when diffracted by the first diffraction element.