Touch Display Panel Black Matrix Infrared Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical type touch panels have a complex structure and high costs due to the requirement of both infrared light emitters and receivers.
Innovation Solution
A touch display panel design featuring a first substrate with a black matrix that transmits light within a specific wavelength range, paired with light sensing elements on a second substrate that become conductive upon receiving this light, generating touch signals through scan and signal lines, thereby simplifying the structure and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical type touch panel uses both infrared light emitters and infrared receivers, then touch functionality is achieved, but structure becomes complex and cost increases
Solution Approach 1:
The patent extracts and removes the infrared light emitter component from the traditional optical touch panel system. By using the display panel's own backlight as the light source and the black matrix as the infrared filter, the system eliminates the need for separate infrared emitters and receivers, thereby simplifying the structure while maintaining touch functionality through the remaining light sensing elements.
Solution Approach 2:
The patent makes the black matrix serve multiple functions: it acts as both the infrared filter and the infrared receiver. The black matrix is configured to block visible light while transmitting infrared light, and its photodetector elements detect infrared signals directly. This multi-functionality eliminates the need for separate infrared receiver components, reducing structural complexity.
2Reliability
If optical type touch panel uses both infrared light emitters and infrared receivers, then touch functionality is achieved, but cost increases
Solution Approach 1:
The patent removes the infrared light emitter component from the bill of materials. By utilizing the existing backlight unit already present in the display panel and the black matrix structure, the invention eliminates the need to source, purchase, and assemble separate infrared emitter components, thereby reducing manufacturing costs.
Solution Approach 2:
The black matrix is designed to perform multiple functions simultaneously: serving as the infrared filter, the infrared receiver, and the touch sensing element. This consolidation reduces the total number of components that need to be manufactured and assembled, leading to lower manufacturing costs while maintaining full touch functionality.
3Measurement precision
If light sensing elements are shaded by black matrix, then touch accuracy improves, but light transmission is reduced
Solution Approach 1:
The patent applies the black matrix with selective optical properties in specific locations where infrared detection is needed. The black matrix material is chosen to have high absorption in the visible range and high transmission in the infrared range, allowing it to shade visible light while permitting infrared light to reach the light sensing elements, thus improving touch accuracy without significantly reducing infrared light transmission.
Solution Approach 2:
The patent changes the optical parameters of the black matrix material to achieve wavelength-selective transmission. By selecting materials with specific spectral characteristics that transmit infrared wavelengths while blocking visible wavelengths, the system maintains high infrared light transmission for accurate touch detection while effectively shading visible light to reduce noise and improve measurement precision.
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 design achieves touch functionality with a simplified structure and lower costs by using a black matrix to filter light and conductive light sensing elements, enhancing touch accuracy and reducing the number of required light sensing elements.
Implementation Method 1
The black matrix is formed on the first substrate and only transmits light within a first wavelength range
Implementation Method 2
The light sensing elements are shaded by the black matrix. Each scan line is connected to a first end of a corresponding light sensing element... The light sensing element is configured to generate a touch signal according to the received light within the first wavelength range
Data Source
AI summary
A touch display panel and a display device are provided. The touch display panel includes a first substrate and a second substrate disposed opposite to each other; a black matrix; and a plurality of light sensing elements, a plurality of scan lines and a plurality of signal lines formed on the second substrate; the black matrix is formed on the first substrate and only transmits light within the first wavelength range; the light sensing elements are shaded by the black matrix; each scan line is connected to a first end of the corresponding light sensing element, and each signal line is connected to a second end of the corresponding light sensing element; and the light sensing element is configured to generate a touch signal according to the received light within the first wavelength range and the scanning signal provided by the scan line and supply the touch signal to the corresponding signal line. The touch display panel has a simple structure and a relatively low cost.