Liquid Crystal Display Photosensor Sensitivity via Elongated Light Receiving Surface
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Solution Overview
Problem
The sensitivity of photosensor elements in liquid crystal displays is compromised due to a limited light receiving surface area, particularly when formed using polycrystalline silicon films, which have low absorbance for infrared rays compared to visible rays, making it difficult to generate light reception data with high sensitivity, especially in dark image displays or when detecting objects with low reflectance.
Innovation Solution
The liquid crystal display is designed with pixel electrodes that have inclined parts extending in directions orthogonal to the main axes, and photosensor elements with light receiving surfaces aligned along these inclined directions, enhancing the light receiving surface area and sensitivity. Additionally, the use of both visible and infrared light in the backlight ensures effective detection in various lighting conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If photosensor elements are formed using polycrystalline silicon films, then the manufacturing process is simplified and integrated with pixel switching elements, but the absorbance for infrared rays is low, reducing detection sensitivity
Solution Approach 1:
The patent changes the shape of the light receiving surface from a conventional planar or simple geometric form to an elongated shape that extends in a specific direction. This dimensional change increases the light receiving surface area, allowing the photosensor elements to capture more infrared light and improve detection sensitivity while maintaining the polycrystalline silicon film manufacturing process
Solution Approach 2:
The patent modifies the geometric parameters of the light receiving surface by extending it in a specific direction to create an elongated shape. This parameter change directly increases the surface area available for light reception, compensating for the low absorbance characteristics of polycrystalline silicon films in the infrared range
2Measurement precision
If the light receiving surface area of photosensor elements is increased, then detection sensitivity improves, but the pixel area occupied by photosensor elements increases, reducing the area available for pixel electrodes
Solution Approach 1:
The patent employs asymmetric design by extending the light receiving surface in a specific direction rather than using a symmetric shape. This asymmetric elongation allows the photosensor element to achieve increased surface area for improved sensitivity while maintaining a compact footprint that minimizes interference with the pixel electrode area
Solution Approach 2:
The patent resolves the area conflict by changing the dimensional configuration of the light receiving surface. Instead of expanding the photosensor element uniformly in all directions, the elongated shape extends in one specific direction, efficiently utilizing the available pixel area while maximizing the light receiving surface area for improved detection sensitivity
3Productivity
If photosensor elements receive visible rays from ambient light, then the liquid crystal panel can function as a display, but noise is introduced into light reception data, reducing detection accuracy
Solution Approach 1:
The patent applies local quality by making the light receiving surface selectively responsive to different wavelengths. The elongated shape and orientation are designed to optimize reception of infrared rays reflected from touch objects while minimizing reception of visible ambient light, thereby reducing noise in the detection data while maintaining display functionality
Solution Approach 2:
The patent utilizes wavelength-selective properties by designing the light receiving surface to preferentially detect infrared radiation. This wavelength discrimination capability allows the system to distinguish between infrared signals from touch objects and visible light from the ambient environment, improving detection accuracy while preserving display performance
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 configuration significantly enhances the sensitivity of photosensor elements, enabling accurate detection of object positions even in low-light environments and improving the reliability of touch panel functionality in liquid crystal displays.
Implementation Method 1
photosensor elements operable to generate light reception data by receiving, at a light receiving surface, incident light which is incident thereon via a liquid crystal layer
Implementation Method 2
a liquid crystal layer is provided between the TFT array substrate and the counter substrate... the transmittance for the light transmitted through the pixel is controlled, whereby the light being transmitted is modulated
Implementation Method 3
the pixel switching element inputs a potential to a pixel electrode so that an electric field generated between the pixel electrode and a common electrode is impressed on the liquid crystal layer, whereby the orientation of liquid crystal molecules in the liquid crystal layer is changed
Data Source
AI summary
Disclosed herein is a liquid crystal display including a liquid crystal panel including, a first substrate, a second substrate opposed to said first substrate, and a liquid crystal layer interposed between said first substrate and said second substrate, a plurality of pixels being arrayed in a first direction and in a second direction orthogonal to said first direction in a pixel area provided in a plane where said first substrate and said second substrate are opposed.