Projection Display Pixel Shift Control for Flicker Reduction
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Solution Overview
Problem
Existing projection-type display apparatuses experience deterioration in display quality when specific display patterns appear in images designated by video data.
Innovation Solution
A projection-type display apparatus that includes a liquid crystal panel, an optical path shifting element, and a display control circuit. The display control circuit supplies data signals to the panel pixels, controls the shift of projected pixel positions, and ensures that the projected pixel positions remain at the same position in specific unit periods across frame periods, with opposite shift directions in subsequent frame periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the projection position is shifted for each unit period to increase resolution, then resolution is improved, but display quality deteriorates when specific display patterns appear
Solution Approach 1:
The patent applies periodic action by implementing a frame period divided into multiple unit periods, where the optical path shifting element shifts the projection position periodically across unit periods within each frame period. This periodic shifting increases resolution by distributing pixel projections across different positions. The cycle is repeated across multiple frame periods to maintain both high resolution and display quality through controlled periodic motion.
Solution Approach 2:
The patent implements dynamics by making the projection position variable rather than fixed. The optical path shifting element dynamically adjusts the projection position of panel pixels across different unit periods within a frame period. This dynamic position control allows the system to achieve higher effective resolution by mapping a limited number of panel pixels to multiple projection positions through temporal and spatial variation.
2Measurement precision
If the projection position is shifted in each unit period, then resolution is increased, but flickering occurs in the displayed image
Solution Approach 1:
The patent uses periodic action to create a regular, predictable shifting pattern of projection positions across unit periods within each frame period. This periodic motion is synchronized across the display system to ensure that the shifting occurs at frequencies that increase resolution while avoiding the human visual system's sensitivity range for flicker detection, thereby reducing perceptible flickering.
Solution Approach 2:
The patent maintains continuity of useful action by ensuring that the projection position shifting occurs smoothly and continuously across unit periods without abrupt interruptions. The optical path shifting element operates continuously to shift projection positions, and the display control circuit maintains continuous control signals, ensuring that the resolution-enhancing action remains uninterrupted and effective throughout the frame period.
Data Source
AI summary
A projection-type display apparatus includes a liquid crystal panel including a panel pixel, an optical path shifting element that shifts a projected pixel projected from the panel pixel, and a display control circuit that controls the liquid crystal panel and the optical path shifting element. The display control circuit supplies, to the liquid crystal panel, the same data signal and controls the projected pixel to be at a same position in each of a unit period f1-1 and a unit period f2-1, and controls the optical path shifting element to cause a shift direction from the projected pixel before the shift toward the projected pixel after the shift from a unit period f1-2 to a unit period f1-4 to be opposite to the shift direction from the projected pixel before the shift toward the projected pixel after the shift from a unit period f2-2 to a unit period f2-4.