Projection Display Optical Path Shift for Unevenness
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Solution Overview
Problem
Projection type display apparatuses experience display unevenness when enlarging images, with bright and dark regions becoming visually distinct due to the optical path shift element's inability to effectively manage pixel projection positions.
Innovation Solution
Incorporating a first and second liquid crystal panel with an optical path shift element and a display control circuit that shifts the projection position every k unit period, converting pixel data for each unit period and supplying it to the respective panels, ensuring the centroid of the projection path for each panel pixel differs, thereby reducing display unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an optical path shift element is used to increase resolution in a projection type display apparatus, then pseudo resolution is improved, but display unevenness occurs with bright and dark regions becoming visually distinct when the projected image is enlarged
Solution Approach 1:
The invention divides the projection period into multiple unit periods (first unit period and second unit period) within one frame period. The optical path shift element shifts the projection position in different unit periods, segmenting the projection process to distribute bright and dark regions across different spatial locations, thereby reducing display unevenness while maintaining pseudo resolution enhancement.
Solution Approach 2:
The invention implements periodic shifting of the projection position by the optical path shift element across multiple unit periods. The projection position is shifted in a periodic manner (e.g., shifted in the first unit period, unshifted or differently shifted in the second unit period), creating a temporal pattern that distributes luminance variations and reduces visible display unevenness.
2Measurement precision
If the projection position is shifted for each unit period to express gradation levels, then pseudo resolution is increased, but display unevenness with bright and dark regions becomes visually recognized
Solution Approach 1:
The projection process is segmented into multiple unit periods with different projection positions. By controlling the optical path shift element to shift positions in different unit periods, the invention segments the luminance distribution across space and time, preventing concentration of bright and dark regions at the same location and thereby improving display uniformity.
Solution Approach 2:
The invention dynamically adjusts the projection position by controlling the optical path shift element to shift at different timings for different colors (e.g., R, G, B). This dynamic positioning strategy ensures that bright and dark regions are distributed across different spatial locations during the frame period, reducing display unevenness while maintaining the pseudo resolution enhancement effect.
3Manufacturing precision
If multiple liquid crystal panels and an optical path shift element are used to reduce display unevenness, then image quality is improved, but device complexity increases
Solution Approach 1:
The optical path shift element serves multiple functions: it shifts the projection position to reduce display unevenness, maintains pseudo resolution enhancement, and enables color separation control. By making this single component multi-functional, the invention achieves display uniformity improvement without proportionally increasing system complexity.
Solution Approach 2:
The optical path shift element acts as an intermediary component between the liquid crystal panels and the projection lens. It mediates the projection position control for multiple colors and panels, simplifying the overall control architecture while achieving the goal of reducing display unevenness through coordinated shifting of multiple panel projections.
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 reduces display unevenness by alternately shifting and overlapping bright and dark regions, improving image quality when projecting enlarged images.
Implementation Method 1
an optical path shift element configured to shift projection positions of the first panel pixel and the second panel pixel
Data Source
AI summary
A projection type display apparatus includes a liquid crystal panel including a first panel pixel, a liquid crystal panel including a second panel pixel, an optical path shift element that shifts projection positions of the first panel pixel and the second panel pixel, and a display control circuit that controls the liquid crystal panel and the optical path shift element. The display control circuit causes the optical path shift element to shift the projection position from a first unit period to a fourth unit period of one frame period for each unit period. A centroid of a path on which the first panel pixel is projected from the first unit period to the fourth unit period is different from a centroid of a path on which the second panel pixel is projected from the first unit period to the fourth unit period.