Side-by-Side TFPD and TFLED Light Emitter Sensor Unit
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Solution Overview
Problem
Current displays with integrated photodiodes face challenges in accurately detecting objects and patterns due to light scattering and the need for complex and costly optical collimators, which increase production costs and reduce signal quality.
Innovation Solution
A light emitter/sensor unit where the photodiode (TFPD) and light emitting diode (TFLED) share a common backplane voltage regulating circuitry, allowing them to be arranged side by side without overlapping, reducing light obstruction and scattering, and enabling independent control of the TFPD for improved detection accuracy and cost-effective production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an optical collimator is placed between the display and the photodetector array to suppress light scattering, then light detection accuracy is improved, but device complexity and production cost increase
Solution Approach 1:
The patent removes the optical collimator from the system entirely. Instead of adding complexity to suppress light scattering, the invention extracts this component and relies on the inherent side-by-side arrangement of TFPD and TFLED elements, along with their common backplane voltage regulating circuitry, to achieve accurate light detection without scattering suppression components.
Solution Approach 2:
The patent segments the display into independent pixel elements where each pixel contains both a TFPD and a TFLED arranged side by side. This segmentation allows each pixel to function as an independent light emission and detection unit, eliminating the need for system-level optical collimators while maintaining detection accuracy.
2Adaptability or versatility
If photodiodes are integrated underneath the display to detect reflected light, then object detection capability is improved, but light scattering increases and detection accuracy decreases
Solution Approach 1:
The patent transitions from a stacked vertical arrangement (photodiodes underneath the display) to a lateral side-by-side arrangement within the same plane. By moving the TFPD and TFLED elements to adjacent positions rather than overlapping positions, the invention eliminates light path interference while maintaining the integrated display and detection functionality.
3Measurement precision
If TFPD and TFLED are arranged side by side with common backplane voltage regulating circuitry, then light scattering is reduced and detection accuracy is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent implements a universal backplane voltage regulating circuitry that serves both the TFPD and TFLED elements simultaneously. This multi-functional circuitry simplifies the manufacturing process by using a single standardized interface for both emission and detection components, reducing the need for separate precision alignment procedures while maintaining side-by-side arrangement benefits.
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 enhances the accuracy of object detection and pattern recognition by minimizing light scattering, eliminates the need for additional scattering reduction means, and lowers production costs by simplifying the manufacturing process.
Implementation Method 1
a thin-film photodiode detector (TFPD) comprising a film configured to absorb light and to convert absorbed light into a current
Implementation Method 2
a thin-film light emitting diode (TFLED) comprising a film configured to convert an electrical current into light
Data Source
Figure 1a
Figure 1b
Figure 2
AI summary
A light emitter/sensor unit (2) for a display (1), the light emitter/sensor unit (2) comprising: a thin-film photodiode detector, TFPD, (5) comprising a film (6) with an upper side (8) and a lower (7) side, the film (6) being configured to absorb light and to convert absorbed light into a current; a first thin-film light-emitting diode, TFLED, (10) comprising a film (16) with an upper side (18) and a lower side (17), the film (16) being configured to convert an electrical current into light; backplane voltage regulating circuitry (30) comprising first (31) and second (32) TFPD contact surfaces, a first TFLED contact surface (41), and transistors, wherein the transistors are configured to set an electrical potential of the first TFLED contact surface (41) and to either set electrical potentials of the two TFPD contact surfaces (31, 32) or to measure a potential difference between the two TFPD contact surfaces (31, 32); wherein the lower side (17) of the film (16) of the first TFLED (10) is electrically connected to the first TFLED contact surface (41), and wherein the lower side (7) of the film (6) of the TFPD (5) is electrically connected to the first TFPD contact surface (31) and the upper side (8) of the film (6) of the TFPD (5) is electrically connected to the second TFPD contact surface (32).