Light Detection Module Using Time-Division Photocurrent Integration
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Solution Overview
Problem
Relative light detection modules require multiple photodiodes connected in parallel to generate large photocurrents, leading to high cost and large space occupation.
Innovation Solution
A light detection module with N light sensing circuits, a control circuit, a capacitance integrating conversion circuit, and a processing circuit, which controls photocurrents in a time division manner to generate analog output voltages, reducing the need for parallel photodiodes by using a capacitance integrating method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple photodiodes are connected in parallel to generate large photocurrents, then the light detection range is improved, but the device occupies large space and increases cost
Solution Approach 1:
The patent segments the light detection process into multiple time slots, with each photodiode dedicated to detecting a specific color wavelength band. Instead of using multiple photodiodes simultaneously in parallel, the system divides the detection task across time, allowing a single photodiode to be sequentially reused for different color detections, thereby reducing the total number of photodiodes needed from three to one.
Solution Approach 2:
The patent implements periodic action by sequentially switching between different light sensing circuits at different time slots. The control circuit periodically switches the connection between the photodiode and the integration capacitor based on the detection wavelength band required, enabling the same hardware to perform multiple detection functions through time-division multiplexing.
2Measurement precision
If multiple photodiodes are connected in parallel to generate large photocurrents, then the light detection range is improved, but the manufacturing cost increases
Solution Approach 1:
The patent segments the light detection process into multiple time slots, with each photodiode dedicated to detecting a specific color wavelength band. Instead of using multiple photodiodes simultaneously in parallel, the system divides the detection task across time, allowing a single photodiode to be sequentially reused for different color detections, thereby reducing the total number of photodiodes needed from three to one.
Solution Approach 2:
The patent makes the single photodiode universal by enabling it to detect multiple color wavelength bands through time-division multiplexing. The same photodiode serves multiple functions by detecting different colors at different time slots, controlled by the control circuit that switches its connection to the integration capacitor based on the required detection band.
3Measurement precision
If multiple photodiodes are connected in parallel to generate large photocurrents, then the light detection range is improved, but the device complexity increases
Solution Approach 1:
The patent merges multiple light sensing circuits into a single integrated system. Instead of having separate parallel circuits for each color detection, the system combines the photodiode, integration capacitor, and control circuit into one unified structure where the same components serve multiple detection functions through time-division multiplexing, thereby reducing overall circuit complexity.
Solution Approach 2:
The patent makes the single photodiode universal by enabling it to detect multiple color wavelength bands through time-division multiplexing. The same photodiode serves multiple functions by detecting different colors at different time slots, controlled by the control circuit that switches its connection to the integration capacitor based on the required detection band.
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
Reduces the number of photodiodes required, saving space and cost while effectively converting small photocurrents into usable signals, allowing for efficient light signal characterization.
Implementation Method 1
N light sensing circuits respectively sense light signals of different colors to generate corresponding photocurrents
Implementation Method 2
the capacitance integrating conversion circuit is configured to perform integrating conversion on the photocurrent according to the conversion parameter and an integration time, to obtain an analog output voltage
Data Source
AI summary
A light detection module, a light detection method and a display device are provided. The light detection module includes N light sensing circuits, a control circuit, a capacitance integrating conversion circuit, and a processing circuit; N is a positive integer; wherein the N light sensing circuits respectively sense light signals of different colors to generate corresponding photocurrents; the control circuit is configured to control to provide photocurrents generated by the light sensing circuits to a capacitance integrating amplifying circuit in a time division manner, and to control a conversion parameter of the capacitance integrating amplifying circuit; the capacitance integrating conversion circuit is configured to perform integrating conversion on the photocurrent according to the conversion parameter and an integration time, to obtain an analog output voltage; the processing circuit is configured to obtain characteristics of the light signal according to the analog output voltage. In the present disclosure, the current integration method is adopted by the capacitance integration conversion circuit, and the photocurrent is converted according to the integration time, so that the number and area of the photodiodes connected in parallel in the light sensing circuit can be reduced by increasing the integration time, the space and cost are reduced.