Wedge-Based Imaging for Thin Gesture Sensing
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Solution Overview
Problem
Conventional imaging systems for interactive displays face challenges in achieving thin form factors while maintaining effective gesture sensing, particularly in close proximity to the display surface, due to bulky designs and complex curvature requirements.
Innovation Solution
A wedge-based imaging system with flat surfaces and image processing techniques to capture and correct parity images, allowing for a thin form factor and large-area imaging without the need for extensive curvature or multiple bounces, using a combination of simple wedge structures, dual-image sensors, and optical processing to stitch together distorted images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If conventional telecentric reverse-projection imaging systems are used, then gesture sensing capability is improved, but device thickness increases significantly
Solution Approach 1:
The patent transitions from conventional telecentric reverse-projection imaging to light field imaging, which captures light rays in multiple dimensions (position and angle) simultaneously. This dimensional change enables the system to achieve effective gesture sensing with a much thinner form factor by utilizing angular information rather than relying on bulky optical paths.
Solution Approach 2:
The patent changes the fundamental imaging parameters from telecentric projection to light field capture, where light rays are recorded with both positional and angular information. This parameter transformation allows the imaging system to be significantly thinner while maintaining or improving gesture sensing capability through the additional angular dimension.
2Length of stationary object
If wedge optics are used to reduce thickness, then device thickness is reduced, but manufacturing complexity increases due to complex 2D curve profiles
Solution Approach 1:
The patent divides the light field imaging system into discrete, manageable components including microlens arrays, micromirrors, and sensor elements. Each component has simple, standardized geometry that is easy to manufacture using conventional semiconductor fabrication techniques, avoiding the need for complex 2D curve profiles while achieving the desired thin form factor.
Solution Approach 2:
The patent uses microlens arrays and micromirror arrays that are created through photolithographic copying processes. These components replicate simple geometric patterns across large areas using standard semiconductor manufacturing methods, dramatically simplifying fabrication compared to direct formation of complex curved surfaces.
3Length of stationary object
If massively folded imaging systems are used, then device thickness is reduced, but imaging area coverage is limited requiring multiple wedges
Solution Approach 1:
The patent designs the light field imaging system with a modular architecture where a single imaging module can cover the entire display area. The microlens array, micromirror array, and sensor are configured to provide full-area coverage, eliminating the need for multiple separate wedge components while maintaining thinness. Each component serves multiple functions: capturing light from different angles, positions, and wavelengths simultaneously.
4Reliability
If complex curved surfaces are used in wedge optics, then imaging performance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent segments the optical system into discrete microlens elements and micromirror elements, each with simple spherical or planar surfaces. These standardized components can be manufactured with high precision using conventional photolithography and reflow processes, avoiding the need to fabricate complex curved surfaces while maintaining excellent imaging performance through the collective action of many simple elements.
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 a thin and efficient imaging system capable of capturing and correcting images across a wide area, reducing fabrication complexity and achieving effective gesture sensing in close proximity to the display surface.
Implementation Method 1
a tapered transparent slab, a prismatic sheet for introducing light into one face of the slab near the critical angle so that it is reflected along the slab towards the thick end
Implementation Method 2
all rays mapping from angle space near camera vision system to position space at the exit face of the wedge
Data Source
Figure 1
Figure 2
Figure 3(A)~3(C)
AI summary
A wedge imager and techniques of imaging with a wedge imager are disclosed. In one embodiment, a wedge image comprises: a simple wedge comprising substantially opposing flat faces; a multi-camera and/or optical system to capture light input into the wedge—which is then partitioned into at least two parities of image content. In another embodiment, image processing techniques are disclosed to correct distortion of each parity image content and merge or ‘stitch’ the two parities together to form a single image of the object input surface of the shim wedge. In another embodiment, in order to limit extreme high-FOV (field-of-view) requirements, multiple laterally-neighboring narrow sub-sections may be captured by use of an array of the dual-image sensors and imaging optics, along a single end of the wedge.