Liquid Crystal Lens for Virtual Image Display
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing virtual image display devices face challenges in improving responsiveness and reducing the size of the focus convergence mechanism, which often results in decreased surface accuracy due to the use of movable parts like lenses and liquid lenses in thin light beam flux projection units.
Innovation Solution
A virtual image display device incorporating a liquid crystal lens that changes focal length with respect to the polarization component of image light, allowing for rapid focus and convergence adjustments while maintaining high surface accuracy by being disposed in front of the eyes on an optical path with a thicker light beam flux.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If movable parts such as a pair of lenses or liquid lens are used in the focus convergence changing unit, then focus and convergence can be adjusted, but responsiveness is difficult to improve and mechanism size cannot be reduced
Solution Approach 1:
The patent replaces the mechanical lens displacement system with a liquid crystal lens that changes focal length through electrical control. The liquid crystal lens uses liquid crystal material whose refractive index changes with applied voltage, enabling focus and convergence adjustment without mechanical movement, thereby improving responsiveness and reducing mechanism size.
Solution Approach 2:
The patent changes the physical state of the liquid crystal material through voltage application, which alters the refractive index and focal length of the lens. By controlling the voltage applied to the liquid crystal lens, the system can rapidly adjust focus and convergence parameters without mechanical movement.
2Volume of moving object
If focus convergence changing unit is incorporated in projection unit with thin light beam flux, then compact design is achieved, but surface accuracy decreases
Solution Approach 1:
The patent replaces mechanical lens components with a liquid crystal lens that has no moving parts. This eliminates the need for precise mechanical alignment and surface accuracy in a thin projection unit, as the liquid crystal lens achieves focus control through electrical field modulation rather than mechanical displacement.
Solution Approach 2:
The liquid crystal lens can be implemented as a thin film structure that maintains optical functionality while minimizing thickness. The liquid crystal material layer is sufficiently thin to accommodate compact projection unit design while maintaining optical precision through electrical control rather than mechanical means.
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 enables rapid focus and convergence adjustments with improved surface accuracy, reducing the burden on the eyes and enhancing the display experience by controlling the display states based on detected object distances.
Implementation Method 1
a liquid crystal lens configured to have a focal length which changes with respect to a polarization component of image light
Data Source
AI summary
A virtual image display device includes a first image display device configured to display a virtual image, a second image display device configured to display a virtual image, a line-of-sight direction distance detection device configured to detect an object distance in a line-of-sight direction of a wearer, an image display control unit configured to control display states of the first image display device and the second image display device in accordance with the object distance, and a liquid crystal lens configured to be disposed in front of eyes of the wearer and configured such that a focal length changes with respect to a s-polarization component of image light emitted from the first image display device and the second image display device.