Optical Sensing Unit Arc-Curved Surface FTIR Touch Panel
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Solution Overview
Problem
Existing Frustrated Total Internal Reflection (FTIR) touch panel devices face challenges in detecting touch locations with precision due to unclear scattered light patterns, especially when using materials with low workability like glass, which increases manufacturing costs and complexity.
Innovation Solution
An optical sensing unit with a flat light guide plate featuring an arc-shaped curved surface that faces a detecting member, enhancing the clarity of detected light and improving detection precision by focusing scattered light effectively, and a touch panel device with multiple optical sensing units positioned at the edges of the light guide plate to compute touch locations accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the light guide plate is made of glass or heat-resistant glass to improve material properties, then the heat resistance and durability are improved, but the workability and manufacturing cost deteriorate due to extremely low workability
Solution Approach 1:
The light guide plate is divided into a first light guide plate and a second light guide plate that are coupled together. The first light guide plate has an arc-shaped curved surface that is easier to manufacture, while the second light guide plate can be made of glass or heat-resistant glass for heat resistance. This segmentation allows each part to be optimized independently, resolving the contradiction between workability and heat resistance.
2Ease of manufacture
If the light guide plate is made of acrylic resin to improve workability, then the ease of manufacture is improved, but the heat resistance deteriorates due to low heat-resistant temperature
Solution Approach 1:
The light guide plate uses a composite structure combining acrylic resin and glass or heat-resistant glass. The acrylic resin portion provides good workability and ease of manufacture, while the glass or heat-resistant glass portion provides the necessary heat resistance. This composite material approach resolves the contradiction between workability and heat resistance by leveraging the strengths of different materials.
3Area of stationary object
If the light guide plate is made large in size to meet display requirements, then the display area is improved, but the manufacturing cost increases due to difficulty in making large size
Solution Approach 1:
The light guide plate is segmented into multiple parts (first and second light guide plates) that can be manufactured separately at manageable sizes and then coupled together to form a large-sized assembly. This segmentation enables each component to be manufactured more easily and cost-effectively, while still achieving the required large display area when assembled.
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 enhances the detection precision of touch locations by clarifying the contour of detected light, allowing for more accurate computation of touch positions and reducing manufacturing costs by simplifying the shaping of the light guide plate.
Implementation Method 1
a touch panel device of a Frustrated Total Internal Reflection (FTIR) type
Implementation Method 2
An optical sensing unit with a flat light guide plate featuring an arc-shaped curved surface that faces a detecting member, enhancing the clarity of detected light and improving detection precision by focusing scattered light effectively
Implementation Method 3
When a finger or pen is touched to the surface of the light guide plate, the light propagating through the light guide plate is scattered. This scattered light is detected by a detection sensor to detect the touch location.
Data Source
AI summary
Provided is an optical sensing member, comprising a light guide plate 102 which propagates light from a light source unit 108, detecting units 104, 106 which detect scattered light from the light guide plate 102 being touched, an optical member which guides the scattered light to the detecting units, and a primary control unit 118 which computes the touch location upon the light guide plate 102 on the basis of information relating to the detected light. The optical member has arc-shaped curved surfaces formed on the end parts which face each of the detecting units. Each of the detecting units outputs, as the information relating to the light which is detected by the detecting units, location information corresponding to the angle of entry to the detecting units of the light which is radiated from the facing arc-shaped curved surfaces. It is thus possible to clarify contours of the light which is detected by the detecting units, and to improve the precision of the detection of the touch location.