Projector Pixel-Shifting Control for Lens Size Reduction

Solution Overview

Problem

High-definition projectors require expensive lenses with low aberration and increased size due to high spatial frequency of display panels, making it difficult to maintain sufficient Modulation Transfer Function (MTF) values, and existing solutions that increase pixel count without changing display panel size lead to complex optical path shifting mechanisms, increasing device size and cost.

Innovation Solution

A projector that uses a pixel-shifting control method to form images with combined pixels as pixel units, shifting temporally continuous images by a pixel pitch in a predetermined direction, allowing the use of projection lenses with MTF values less than 50% of the display panel's spatial frequency without degrading image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high-definition display panels with high spatial frequency are used, then image resolution is improved, but lens size and cost increase due to the need for low-aberration lenses with sufficient MTF values

Engineering Contradiction:

Improveimage resolutionVSAvoidlens size

Core Design Contradiction:

Manufacturing precisionVSVolume of moving object

Solution Approach 1:

The patent applies dynamic control by shifting the image position on the display panel during operation. By controlling the image to shift by half a pixel pitch in the vertical direction and by a pixel pitch in the horizontal direction, the system dynamically changes which pixels are activated, effectively doubling the resolution without requiring higher-resolution hardware

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the display panel by adjusting the image position and pixel activation patterns. By modifying the spatial frequency utilization through image shifting and selective pixel activation, the system achieves effective resolution doubling while maintaining compatibility with existing lower-resolution lenses

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If high-definition display panels with high spatial frequency are used, then image resolution is improved, but lens cost increases due to the need for low-aberration lenses

Engineering Contradiction:

Improveimage resolutionVSAvoidlens cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies dynamic control by shifting the image position on the display panel during operation. By controlling the image to shift by half a pixel pitch in the vertical direction and by a pixel pitch in the horizontal direction, the system dynamically changes which pixels are activated, effectively doubling the resolution without requiring higher-resolution hardware

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the display panel by adjusting the image position and pixel activation patterns. By modifying the spatial frequency utilization through image shifting and selective pixel activation, the system achieves effective resolution doubling while maintaining compatibility with existing lower-resolution lenses

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If optical path shifting mechanisms are added to increase pixel count, then projected image resolution is improved, but device complexity and size increase

Engineering Contradiction:

Improveprojected image resolutionVSAvoidoptical path shifting mechanism

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts the resolution enhancement function from the optical system and relocates it to the display panel control system. By implementing image shifting and pixel activation control at the panel level rather than through optical path shifting mechanisms, the patent eliminates complex mechanical or optical components while achieving the same resolution doubling effect

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces potential mechanical or optical path shifting mechanisms with an electronic control system that manipulates image positions and pixel activation patterns. This substitution eliminates moving parts and complex optical components, reducing device complexity and size while maintaining the resolution enhancement function

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS9838655B2Projector and image displaying method

Publication Date: 2017.12.05 SHARP NEC DISPLAY SOLUTIONS LTD

AI summary

A projector includes a DMD that forms an image, a projection lens that projects the image formed by the DMD on a projected surface, and a display control unit that controls an image forming operation of the DMD. The display control unit forms a frame image by sequentially forming a plurality of images using a combined pixel which is configured of a plurality of pixels, and with respect to temporally continuous two images, the display control unit forms one image at a position that is shifted by a distance that corresponds to the pixel pitch of the DMD in a predetermined direction relative to the other image.