Optical Touch Detection Using Display Border Light Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical imaging systems for touch control in consumer electronics face challenges with accuracy and manufacturing cost due to the need for a reflecting frame and sensor to be installed on the same plane, making assembly difficult and costly, and often resulting in unsatisfactory touch control accuracy.
Innovation Solution
An optical imaging system that includes a display panel, a light source module, two image sensors, and a control module, where the light source emits light that is reflected by a touch object with reflective sections, allowing the image sensors to capture signals which the control module uses to determine the moving direction of the touch object, eliminating the need for a reflecting frame and enhancing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a reflecting frame is used to isolate interference outside the coordinate detecting area, then the touch control accuracy is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent removes the reflecting frame component from the system by using the display panel border itself as the light-blocking structure. This extraction of the unnecessary component simplifies the device structure while maintaining the interference isolation function, directly resolving the contradiction between accuracy and complexity.
Solution Approach 2:
The display panel border is given a dual function: it serves as both the display boundary and the light-blocking structure for interference isolation. This multi-functionality eliminates the need for a separate reflecting frame, reducing device complexity while preserving touch control accuracy.
2Measurement precision
If the reflecting frame and sensor are installed on the same plane, then the touch control accuracy is improved, but the ease of manufacture deteriorates
Solution Approach 1:
The patent changes the spatial arrangement from a same-plane configuration to a multi-dimensional layout where sensors are positioned at corners of the display panel. This dimensional change allows sensors to be integrated into the display structure without requiring precise same-plane alignment with a reflecting frame, significantly easing manufacturing while maintaining detection accuracy.
3Reliability
If a reflecting frame is used to block interference, then the reliability of touch detection is improved, but the productivity and assembly ease deteriorate
Solution Approach 1:
By removing the reflecting frame component entirely and using the display panel border for light blocking, the system reduces the number of parts that need to be assembled. This extraction simplifies the assembly process, improving productivity and assembly ease while maintaining reliable touch detection through the simplified structure.
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
This solution allows for accurate detection of touch object movement in various directions, including vertical, horizontal, and rotational movements, reducing assembly complexity and manufacturing costs while improving touch control accuracy, enabling wider practical application of touch objects like styluses.
Implementation Method 1
a touch object (56), and a first image sensor (58), a second image sensor (60)... The touch object includes at least one reflective section for reflecting the light emitted from the light source module
Data Source
AI summary
An optical imaging system includes a display panel, a light source module, a touch object, a first image capturing module, a second image capturing module and a control module. The touch object moves from a first position at a first time to a second position at a second time. The first image capturing module and the second image capturing module respectively capture light reflected from the touch object, so as to generate a first signal, a second signal, a third signal and a fourth signal corresponding to the touch object at the first time and the second time. The control module computes a moving direction of the touch object according to variation of the first signal, the second signal, the third signal and the fourth signal.