Array Substrate Low Temperature Compensation Circuit

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Solution Overview

Problem

Liquid crystal display panels experience a significant drop in voltage-transmittance and image quality at low temperatures, leading to poor brightness, contrast, and gamut differences compared to normal temperature states, affecting user experience.

Innovation Solution

An array substrate with low temperature compensation circuits, comprising a divider resistance and a diode-capacitance series branch, which adjusts voltage signals to maintain consistent transmittance by reducing voltage input to data lines as temperature decreases, ensuring the voltage-transmittance curve aligns with normal temperature performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If traditional low temperature poly silicon liquid crystal display is used, then the device can operate at low temperatures, but the voltage-transmittance drops significantly and image quality deteriorates

Engineering Contradiction:
Improvelow temperature operation capabilityVSAvoidvoltage-transmittance stability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent changes the electrical parameters (voltage and transmittance) through temperature-dependent compensation circuits. The compensation circuit adjusts the voltage-transmittance characteristics based on temperature variations, transforming the fixed parameter relationship into a dynamically adjustable one that maintains stability across temperature ranges.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where the compensation circuit monitors temperature changes and adjusts the voltage signal accordingly. The compensation amount is determined by the temperature difference from a reference point, creating a closed-loop system that automatically corrects for temperature-induced performance degradation.

Inventive Principle:
Principle #23Feedback

2Illumination intensity

If voltage signals are increased to compensate for low temperature transmittance loss, then transmittance improves, but the voltage-transmittance curve shifts and normal temperature performance is affected

Engineering Contradiction:
ImprovetransmittanceVSAvoidvoltage-transmittance curve consistency
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by providing temperature-specific compensation only when needed. The compensation circuit is designed to activate or adjust based on temperature conditions, applying different compensation strategies for low temperature versus normal temperature operation, rather than using a fixed compensation approach that would affect all operating conditions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent makes the compensation system dynamic by allowing the compensation amount to vary with temperature. The compensation circuit adjusts its characteristics based on the temperature signal, transforming a static voltage-transmittance relationship into a dynamic one that adapts to changing thermal conditions while maintaining curve consistency.

Inventive Principle:
Principle #15Dynamics

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 solution maintains the quality of the display image in low temperature environments by shifting the voltage-transmittance curve towards higher voltages, ensuring consistent performance with normal temperature settings, thereby enhancing user experience.

Implementation Method 1

utilizing a temperature difference between a positive temperature coefficient resistance and a negative temperature coefficient resistance to generate a temperature compensation signal

Methodology Applied
Scientific EffectTemperature-dependent voltage difference:

Data Source

PatentEP3200012B1Array substrate, liquid crystal display panel and display device
Publication Date: 2019.06.26 BOE TECHNOLOGY GROUP CO LTD
  • EP3200012B1 patent drawingFigure 1
  • EP3200012B1 patent drawingFigure 2a
  • EP3200012B1 patent drawingFigure 2b

AI summary

The embodiments of the present invention disclose an array substrate, a liquid crystal display panel and a display device. Low temperature compensation circuits one-to-one corresponding to the data lines are added to the peripheral area of the array substrate; each low temperature compensation circuit comprises a first branch and a second branch connected in parallel; wherein the first branch comprises a divider resistance; the second branch comprises a diode and a capacitance connected in series; in the second branch the position of the diode and the position of the capacitance can be interchanged. Since the voltage difference between the both terminals of the diode rises with the temperature decreasing, the voltage difference on the route comprising the diode and the capacitance rises when the temperature decreases; a divider resistance is used in the route to divide the voltage of the voltage signal inputted at the data signal receiving terminal, reducing the voltage signal inputted to the input terminal of the data line. The reduced voltage signal brings a higher transmittance, compensating the integral shift of the voltage-transmittance curve in low temperature environment, such that the voltage-transmittance curve at low temperature is kept in accordance with that at normal temperature.