Touch Pressure Sensing via Optical Filter in Non-Display Area
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Solution Overview
Problem
Current touch sensing apparatuses can only detect touch position and not effectively measure touch pressure, limiting their application and functionality.
Innovation Solution
An apparatus comprising a display panel, a window with a non-display area, a first sensor with a first optical filter and photo detector, and a controller that calculates touch pressure based on the intensity of light transmitted through the filter, which changes with applied pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional touch sensing apparatuses are used, then touch position can be detected, but touch pressure cannot be effectively measured
Solution Approach 1:
The patent introduces an optical filter as an intermediary element between the display panel and the photo detector. This optical filter modulates light transmission based on applied pressure, enabling pressure measurement without directly measuring mechanical force. The optical filter acts as a mediator that converts pressure information into optical signal variations that can be detected by the photo detector.
Solution Approach 2:
The patent replaces direct mechanical pressure sensing with an optical measurement system. Instead of using mechanical sensors that directly contact and measure pressure, the system uses light transmission through an optical filter that changes its optical properties under pressure. This substitutes a mechanical measurement approach with an optical one, enabling pressure detection while maintaining display integrity.
2Adaptability or versatility
If touch pressure sensing is added to display area, then pressure detection capability is improved, but display quality and uniformity deteriorate
Solution Approach 1:
The patent divides the sensing function into two separate spatial zones: the display area maintains pure display functionality while the non-display area houses the pressure sensing components. The optical filter is positioned in the non-display area where it can modify light for pressure sensing purposes without interfering with the visual display quality. This segmentation allows the system to gain pressure detection capability while preserving display uniformity and quality.
Solution Approach 2:
The patent applies different functional qualities to different spatial regions of the device. The display area maintains optimized optical properties for visual output, while the non-display area incorporates the optical filter and photo detector with properties optimized for pressure sensing. This local differentiation of functional quality allows each region to perform its specialized function without compromising the other.
3Measurement precision
If sensors are disposed in the display area, then touch pressure can be sensed, but light transmission and display quality are affected
Solution Approach 1:
The patent moves the pressure sensing function from the optical path dimension to a spatial dimension by placing sensors in the non-display area. Instead of embedding sensors within the display layers that would block or scatter light, the system uses the spatial separation between display and non-display areas to position sensing components outside the critical light transmission path, thus avoiding illumination interference.
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
Enables accurate and sensitive measurement of touch pressure, enhancing the functionality of touch sensing apparatuses by allowing for pressure input detection.
Implementation Method 1
a first sensor including a first optical filter and a first photo detector configured to generate a first sensing value corresponding to an intensity of light transmitted through the first optical filter from the display panel
Implementation Method 2
the first sensor including a first optical filter and a first photo detector configured to generate a first sensing value corresponding to an intensity of light transmitted through the first optical filter from the display panel
Data Source
AI summary
An apparatus for sensing a touch pressure includes a display panel configured to display images, a window located on the display panel, the window including a display area and a non-display area at the outside of the display area, a first sensor disposed to align with the non-display area, the first sensor including a first optical filter and a first photo detector configured to generate a first sensing value corresponding to an intensity of light transmitted through the first optical filter from the display panel, and a controller configured to calculate a magnitude of a touch pressure based on the first sensing value.