Input-Output Device with Segmented LED and IR Filter for Photodetection
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Solution Overview
Problem
Conventional input-output devices employing a field-sequential method suffer from low accuracy of photodetection due to short light incidence time and interference from external environmental light, leading to noise and misidentification of data.
Innovation Solution
Incorporating a light unit with multiple visible light-emitting diodes and an infrared light-emitting diode, along with photodetectors equipped with filters, to reduce environmental light influence and enhance data accuracy by lengthening light incidence time and using differential data processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a field-sequential method is used to switch multiple light-emitting diodes sequentially, then full-color images can be displayed, but the light incidence time in each photodetector becomes short, reducing photodetection accuracy
Solution Approach 1:
The light unit is segmented into multiple independent light-emitting regions, each with its own light-emitting diode. This allows different regions to emit light simultaneously or independently, enabling the system to maintain color display capability while providing sufficient light incidence time to photodetectors without the sequential switching limitation.
2Adaptability or versatility
If environmental light enters the input-output device during photodetection, then external light can be detected, but noise is generated and photodetection accuracy is reduced
Solution Approach 1:
A light-emitting diode emitting infrared light is introduced as an intermediary source. The photodetector is equipped with an infrared-pass filter that allows only infrared light to reach the photoelectric conversion element. This intermediary infrared light source enables the system to distinguish between intentional infrared illumination and environmental visible light, eliminating noise from environmental light while maintaining the ability to detect reflected light from objects.
3Adaptability or versatility
If multiple light-emitting diodes are switched sequentially to control backlight lighting state, then color switching is achieved, but the time available for optical data generation in each photodetector is reduced
Solution Approach 1:
The light unit is divided into multiple independently controllable light-emitting regions. Each region can be controlled to emit light simultaneously or independently, allowing the system to maintain lighting control flexibility while extending the light incidence time available for optical data generation in each photodetector.
Solution Approach 2:
The light-emitting diodes are controlled to emit light in periodic cycles, with different regions emitting light during different time periods. This periodic action allows the system to cycle through different lighting states and color combinations while ensuring that each photodetector receives sufficient light incidence time for accurate optical data generation.
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 significantly improves photodetection accuracy by minimizing environmental light interference and allowing longer light exposure times, effectively distinguishing intended data from noise.
Implementation Method 1
generating data based on the illuminance of incident light
Implementation Method 2
including a filter for absorbing light with a wavelength in a visible light range
Implementation Method 3
a plurality of first light-emitting diodes that emit visible light and a second light-emitting diode that emits infrared light
Data Source
AI summary
Accuracy of photodetection is improved. An input-output device includes a light unit including Z (Z is a natural number of 3 or more) first light-emitting diodes that emit light with a wavelength in a visible light range and a second light-emitting diode that emits light with a wavelength in an infrared range; a display circuit that is supplied with a display selection signal, supplied with a display data signal in accordance with the display selection signal, and set to be in a display state based on data of the input display data signal; and Y (Y is a natural number) photodetectors including a filter for absorbing light with a wavelength in a visible light range, supplied with a photodetection control signal is input, and generating data based on the illuminance of incident light in accordance with the input photodetection control signal.