Display Device Ambient Light Detection Voltage Control
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Solution Overview
Problem
Display devices struggle to accurately detect ambient light intensity due to interference from the backlight light source, leading to errors in photocurrent detection.
Innovation Solution
Incorporating a supply voltage control unit that modulates the voltage supplied to the photo sensing unit based on the operation status of the backlight light source, using different voltages when the backlight is on and off to minimize interference and ensure accurate photocurrent detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the photo sensing unit operates continuously with fixed voltage to detect ambient light, then the detection circuit is simple, but the detection accuracy is degraded due to backlight interference
Solution Approach 1:
The patent applies dynamics by making the photo sensing unit's operating voltage variable rather than fixed. The voltage supply unit dynamically adjusts the voltage based on the backlight light source's operating state: applying first voltage when backlight is off for accurate ambient light detection, and second voltage (lower than first) when backlight is on to reduce interference. This dynamic voltage adjustment resolves the contradiction between detection accuracy and circuit simplicity.
Solution Approach 2:
The patent changes the electrical parameter (voltage) of the photo sensing unit based on the backlight operating state. By switching between first voltage (when backlight is off) and second voltage (when backlight is on), the system optimizes the photo sensing unit's performance for ambient light detection while minimizing backlight interference, thereby improving measurement precision without requiring complex hardware modifications.
2Measurement precision
If the voltage to photo sensing unit is increased to maximize photocurrent output, then detection sensitivity improves, but interference from backlight light source increases
Solution Approach 1:
The system dynamically adjusts the voltage applied to the photo sensing unit based on the backlight's operational state. When the backlight is turned off, the first voltage (higher) is applied to maximize photocurrent and detection sensitivity. When the backlight is turned on, the second voltage (lower) is applied to reduce the harmful effect of backlight interference. This dynamic adjustment resolves the contradiction between sensitivity and interference.
Solution Approach 2:
The patent applies preliminary anti-action by proactively reducing the voltage to the photo sensing unit when the backlight is about to operate or is operating, thereby preemptively minimizing the harmful effects of backlight interference on detection accuracy. This preventive approach allows the system to maintain high sensitivity during backlight-off periods while avoiding interference during backlight-on periods.
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 approach allows for high-accuracy detection of ambient light intensity by reducing errors in photocurrent measurement, enabling the display device to accurately modulate backlight intensity.
Implementation Method 1
a photo sensing unit capable of detecting the light intensity of ambient light and outputting a photocurrent corresponding to the light intensity of ambient light
Data Source
AI summary
A display device capable of detecting the light intensity of ambient light with high accuracy is disclosed. The display device has a backlight light source and a photo sensing unit. The display device also includes a voltage supply unit for providing a voltage, which makes the photo sensing unit output a certain amount of photocurrent to the photo sensing unit; and a supply voltage control unit for modulating the voltage supplied to the photo sensing unit based on the operation status of the backlight light source. The supply voltage control unit controls the voltage supply unit by the way of outputting a voltage of a first voltage to the photo sensing unit while the backlight light source is operating; and outputting a voltage of a second voltage, which is different from the first voltage, to the photo sensing unit while the backlight light source is not operating.