Edge Camera Multi-Touch Sensing for Thin Displays
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Solution Overview
Problem
Existing multi-touch sensing devices are thick and degrade the quality and resolution of touch images due to the arrangement of the array type substrate below the LED display panel, limiting their use in portable devices.
Innovation Solution
A multi-touch sensing apparatus with a camera arranged at the edge of the device, emitting light to sense touch images generated on a display panel, utilizing a sensing light source, optical shutter, or mirror to improve resolution and reduce thickness, and incorporating a transparent layer for total internal reflection to enhance image sensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the array type substrate is arranged below the LED display panel, then the display structure is compact, but the touch image quality and resolution are degraded
Solution Approach 1:
The camera is extracted from the traditional position below the display panel and relocated to the edge of the device. This extraction removes the interfering substrate arrangement from the touch sensing path, allowing high-resolution touch image capture without degradation from underlying array structures.
Solution Approach 2:
The touch sensing approach transitions from a vertical arrangement (camera below the panel) to a lateral arrangement (camera at the edge). This dimensional change allows the camera to capture touch images from the side, avoiding interference from the substrate while maintaining compact device structure.
2Length of moving object
If a traditional multi-touch sensing device is used, then touch sensing is achieved, but the device thickness is increased
Solution Approach 1:
The system transitions from vertical stacking (increasing thickness) to lateral positioning (edge placement). By positioning the camera at the device edge and using side-illuminated sensing, the design achieves touch sensing capability without increasing device thickness, as the light path and camera are arranged horizontally rather than vertically.
Solution Approach 2:
The device is segmented into distinct functional zones: the display panel occupies the front surface, while the camera and sensing components are segregated to the edge region. This spatial segmentation allows thin-profile construction while maintaining both display and sensing functions.
3Length of moving object
If the camera is arranged at the edge of the device, then device thickness is reduced, but the touch image sensing area must be optimized
Solution Approach 1:
The display panel incorporates a localized transparent region at the edge area that corresponds to the camera's position. This local modification allows light to pass through to the touch surface for sensing, while the rest of the panel maintains its normal opaque display function. The transparent layer is strategically positioned to maximize sensing area from the edge camera location.
Solution Approach 2:
A transparent layer is introduced as an intermediary element between the edge camera and the touch surface. This mediator allows optical transmission from the camera through the panel edge to the touch-sensitive area, enabling the camera to capture touch images without requiring the entire panel to be transparent.
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 high-resolution touch image sensing, reduces device thickness, and improves image quality by correcting distortions and enhancing sensitivity, making it suitable for flat displays and portable devices.
Implementation Method 1
The sensing light source may be arranged to emit the light to an inside of a transparent layer, and the transparent layer may be located on an upper side of the display panel, and generate a total internal reflection of the light emitted from the sensing light source.
Data Source
AI summary
A multi-touch sensing apparatus using a rear view camera of an array type is provided. The multi-touch sensing apparatus may include a display panel to display an image, a sensing light source to emit light to sense a touch image which is generated by an object and displayed on a back side of the display panel, and a camera to divide and sense the touch image. The camera may be arranged in an edge of a lower side of the multi-touch sensing apparatus, or a mirror to reflect the touch image may be included in the multi-touch sensing apparatus.