Photodetection Sensor Under Display With Low Refractive Index Adhesive
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Solution Overview
Problem
Conventional photodetection devices integrated with display apparatuses suffer from low signal-to-noise ratio and optical diffraction issues, leading to distorted images and low photoelectric conversion efficiency, especially when detecting visible light, which interferes with X-ray detection applications.
Innovation Solution
A photodetection apparatus is designed with a display unit, low refractive index adhesive, and photodetection sensors, where the display unit has a light transmittance greater than 3% and the adhesive refractive index is less than 1.4, enhancing light entry and reducing reflection, thereby improving photoelectric conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If photodetection sensors are integrated with display apparatuses to enable photodetection function, then the display apparatus gains additional functionality, but the signal-to-noise ratio deteriorates due to environmental visible light interference and optical diffraction
Solution Approach 1:
The patent applies local quality by implementing a reflective layer specifically at the bottom surface of the housing to redirect light toward photodetection sensors, while the display screen and other components maintain their original properties. This localized modification improves light collection efficiency without affecting other parts of the system, thereby enhancing the signal-to-noise ratio while preserving the photodetection function.
Solution Approach 2:
The patent introduces a reflective layer as an intermediary element between the external environment and the photodetection sensors. This reflective layer mediates the interaction by redirecting ambient light toward the sensors, increasing the strength of detected signals without introducing additional noise sources, thus improving the overall signal-to-noise ratio.
2Ease of manufacture
If conventional photodetection devices are used with semiconducting material, then manufacturing can be integrated with TFT production equipment, but photoelectric conversion efficiency deteriorates due to band gap absorption of visible light
Solution Approach 1:
The patent inverts the conventional approach by placing photodetection sensors beneath the display apparatus rather than integrating them directly in the TFT layer. This inverted configuration allows the use of alternative photodetection materials that may have superior photoelectric conversion efficiency while still utilizing existing manufacturing capabilities, thereby resolving the trade-off between ease of manufacture and energy conversion efficiency.
Solution Approach 2:
The patent transitions from a planar integration approach to a three-dimensional configuration by positioning photodetection sensors in a separate layer beneath the display. This dimensional change enables independent optimization of photodetection materials and structures without being constrained by TFT manufacturing limitations, thus improving photoelectric conversion efficiency while maintaining manufacturing feasibility.
3Shape
If incident light passes through multiple layers of the photodetection display apparatus, then the display structure is maintained, but image quality deteriorates due to optical diffraction and distortion
Solution Approach 1:
The patent extracts the photodetection function from the main display light path by positioning sensors beneath the housing rather than requiring light to pass through multiple display layers. This extraction eliminates optical diffraction and distortion issues while preserving the display structure, as photodetection now occurs through a separate optical path that does not interfere with image quality.
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 signal-to-noise ratio and photoelectric conversion efficiency, allowing for better detection of visible and infrared light, improving image reconstruction and enabling more effective photodetection functions in display apparatuses.
Implementation Method 1
a low refractive index adhesive disposed between the display unit and the at least one photodetection sensor. The low refractive index adhesive has a refractive index smaller than that of the at least one photodetection sensor
Implementation Method 2
a photodetection film that is electrically connected to the pixel thin film circuit and that is adapted to receive an incident light and to convert the incident light into an optoelectronic signal
Data Source
AI summary
A photodetection apparatus includes a display unit (102), a photodetection sensor (104) disposed beneath the display unit (102), a low refractive index adhesive (103) disposed between the display unit (102) and the photodetection sensor (104), and a main circuit board (106) disposed below the photodetection sensor (104). The display unit (102) includes a display member having a light transmittance greater than 3%. The photodetection sensor (104) includes a pixel thin film circuit (91) and a photodetection film (92) electrically connected to the pixel thin film circuit (91) and is adapted to receive an incident light and to convert the incident light into an optoelectronic signal. The low refractive index adhesive (103) has a refractive index smaller than that of the photodetection sensor (104).