Wire Grid Element Incident Angle Optimization for Projector Contrast
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Solution Overview
Problem
Current reflection type projectors have a margin for improving the contrast ratio, as existing wire grid elements do not optimize the separation of P-polarized and S-polarized light effectively.
Innovation Solution
Incorporating a wire grid element inclined at an angle between 37° and 45° with respect to the normal direction of the liquid crystal panel's light-exit surface, and optionally using a second wire grid element for different light wavelengths, to enhance the separation of polarized light and improve contrast ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wire grid element is disposed at 45° with respect to the normal direction of the liquid crystal panel, then the polarized light splitting function is achieved, but the contrast ratio has room for improvement
Solution Approach 1:
The patent changes the incident angle parameter from the conventional 45° to a range of 30°-40° (preferably 33°-37°) to optimize the contrast ratio. This parameter modification improves the separation efficiency between P-polarized and S-polarized light, thereby enhancing the contrast ratio without requiring complex structural changes.
Solution Approach 2:
The patent introduces an adjustable mechanism that allows the incident angle of the wire grid element to be dynamically adjusted. This enables optimization of the contrast ratio by finding the optimal angle within the 30°-40° range, and also provides adaptability to different operating conditions, resolving the contradiction between achieving high contrast ratio and maintaining manufacturing precision.
2Reliability
If the wire grid element incident angle is reduced below 45° to improve contrast ratio, then the separation capability into P-polarized and S-polarized light is improved, but the structural configuration becomes less conventional
Solution Approach 1:
The patent modifies the incident angle parameter to 30°-40° to improve polarized light separation capability. This parameter change enhances the contrast ratio by improving the differentiation between P-polarized and S-polarized light, while maintaining a relatively simple optical system configuration that does not require fundamental redesign.
Solution Approach 2:
The patent applies the optimized incident angle specifically to the wire grid element's interaction with the liquid crystal panel, creating a localized optimization point. This local quality improvement at the critical interface enhances overall system performance without requiring complex changes throughout the entire optical system.
3Adaptability or versatility
If a wire grid element is used instead of a PBS, then the incident angle dependency of polarized-light splitting is reduced, but the optimal angle is not yet determined
Solution Approach 1:
The patent implements an adjustable mechanism for the wire grid element that enables dynamic optimization of the incident angle. This resolves the uncertainty about the optimal angle by allowing systematic adjustment and measurement to find the best angle within the 30°-40° range, while maintaining the advantage of reduced incident angle dependency characteristic of wire grid elements.
Solution Approach 2:
The patent introduces a feedback mechanism that allows for measurement and optimization of the incident angle. By monitoring the contrast ratio and polarized light separation performance, the system can adjust the incident angle to the optimal value within the 30°-40° range, thereby determining the precise optimal angle through iterative optimization.
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 significantly improves the contrast ratio by optimizing the separation of P-polarized and S-polarized light, leading to better visual sensitivity and overall image quality.
Implementation Method 1
a wire grid element which includes a plurality of metal wires extending so as to be almost parallel to a light-exit surface of the liquid crystal panel within a surface on which the first light is incident
Implementation Method 2
the first light modulated and reflected by the first liquid crystal panel is incident on the first wire grid element
Implementation Method 3
the surface on which the first light is incident is inclined by an angle equal to or greater than 37° and less than 45° with respect to a normal direction of the light-exit surface of the first liquid crystal panel
Data Source
AI summary
A projector includes: an illumination optical system which emits first light (green light); a reflection type first liquid crystal panel which modulates the first light emitted from the illumination optical system; a first wire grid element which is disposed at a position at which the first light modulated and reflected by the first liquid crystal panel is incident, which includes a plurality of metal wires extending so as to be almost parallel to a light-exit surface of the first liquid crystal panel, and in which the surface on which the first light is incident is inclined by an angle equal to or greater than 37° and less than 45° with respect to a normal direction of the light-exit surface of the first liquid crystal panel; a projection optical system which projects the first light modulated by the first liquid crystal panel and reflected from the first wire grid element.