Projector Polarization Conversion Unit for Light Efficiency
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Solution Overview
Problem
Existing single-plate projectors using nonpolarized light sources suffer from reduced light use efficiency due to polarization direction mismatch, leading to inefficient light utilization and increased weight due to complex optical configurations.
Innovation Solution
A projector design incorporating a light source that emits non-linearly polarized light, a polarization conversion unit with a polarizing separator and phase difference plate to convert non-linearly polarized light into linearly polarized light, and a superimposing optical system to efficiently modulate and project the light using a liquid crystal panel, reducing weight and improving light use efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If an incident-side polarization plate is provided to make predetermined linearly polarized light incident on the liquid crystal panel, then the light modulation can be achieved, but light use efficiency deteriorates because light in polarization directions different from the transmission axis is cut
Solution Approach 1:
The invention changes the polarization state parameter of the light from non-linearly polarized to linearly polarized by introducing a polarization conversion unit. This conversion allows the light to match the transmission axis of the incident-side polarization plate, eliminating light loss and improving light use efficiency without requiring complex optical configurations
Solution Approach 2:
The polarization conversion unit acts as an intermediary between the light source and the liquid crystal panel. It converts non-linearly polarized light into linearly polarized light with the appropriate polarization direction, serving as a mediator that enables efficient light transmission through the incident-side polarization plate while maintaining system simplicity
2Ease of operation
If nonpolarized light is transmitted through the incident-side polarization plate, then light in polarization directions different from the transmission axis is cut, but this leads to reduced light use efficiency
Solution Approach 1:
The polarization conversion unit performs preliminary action by converting non-linearly polarized light into linearly polarized light before the light reaches the incident-side polarization plate. This pre-conversion ensures that the light already has the correct polarization direction, allowing easy transmission through the plate without cutting any light components and maintaining high light use efficiency
3Use of energy by moving object
If a complex optical configuration is used to achieve efficient light utilization, then light use efficiency improves, but the weight of the projector increases
Solution Approach 1:
The invention extracts only the essential function needed for efficient light utilization - the polarization conversion unit that converts non-linearly polarized light to linearly polarized light. By removing unnecessary complex optical components and keeping only the critical polarization conversion function, the system achieves high light use efficiency while minimizing projector weight
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 enhances light use efficiency and reduces the projector's size by effectively converting non-linearly polarized light into linearly polarized light, aligning it with the liquid crystal panel's polarization direction, thereby improving image quality and minimizing the projector's weight and dimensions.
Implementation Method 1
the polarizing separation plate separates the first light by transmitting a first linearly polarized light component in the first light toward the superimposing optical system as the second light and reflecting, as the third light, a second linearly polarized light component in a polarization direction different from a polarization direction of the first linearly polarized light component in the first light
Implementation Method 2
a phase difference plate configured to align polarization directions of the second light and the third light
Implementation Method 3
the reflection plate reflects the third light made incident from the polarizing separation plate toward the superimposing optical system
Data Source
AI summary
A projector of the present disclosure includes a light source configured to emit first light, which is non-linearly polarized light, a polarization conversion unit configured to convert the first light into predetermined linearly polarized light, a light modulation device including a liquid crystal panel which modulates the predetermined linearly polarized light, and a superimposing optical system configured to superimpose, on the liquid crystal panel, the predetermined linearly polarized light made incident from the polarization conversion unit. The polarization conversion unit includes a polarizing separator configured to separate the first light into second light and third light and a phase difference plate. The polarizing separator includes a polarizing separation plate and a reflection plate disposed to be separated from and opposed to each other, the polarizing separation plate is provided in a tilted state with respect to a principal ray of the first light and separates the first light by transmitting a first linearly polarized light component in the first light toward the superimposing optical system as the second light and reflecting, as the third light, a second linearly polarized light component in the first light, and the reflection plate reflects the third light toward the superimposing optical system.