Display Device Analog-to-Digital Converter Subpixel Compensation

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Solution Overview

Problem

Display devices face degradation in image quality due to long-term use, as subpixel driving circuit elements deteriorate, leading to changes in subpixel characteristic values that are difficult to compensate for, especially in abnormal subpixels.

Innovation Solution

A display device and method that utilize a reference voltage line and an analog-to-digital converter to sense subpixel characteristic values, adjust voltage levels of driving and analog-to-digital converting reference voltages based on sensed values, and perform compensation during off-sensing periods to maintain image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional fixed reference voltage sensing is used, then the device structure remains simple, but compensation accuracy deteriorates for abnormal subpixels with extreme characteristic values

Engineering Contradiction:

Improvesubpixel characteristic value sensing accuracyVSAvoidvoltage adjustment mechanism complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the reference voltage adjustable rather than fixed. The reference voltage line dynamically changes its voltage level based on the sensed characteristic values of subpixels. This allows the sensing system to adapt to different subpixel conditions, particularly abnormal subpixels with extreme characteristic values, thereby improving measurement precision without requiring completely separate sensing systems for different cases.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the voltage parameter of the reference voltage line from a fixed value to a variable value. By adjusting the voltage level of the reference voltage according to the sensed characteristic values, the system can optimize the sensing range and accuracy for different subpixel conditions. This parameter change enables accurate compensation even for abnormal subpixels that would saturate or fall outside the measurement range with fixed reference voltages.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If separate sensing systems are used for normal and abnormal subpixels, then measurement precision improves, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvecompensation accuracy for abnormal subpixelsVSAvoidmanufacturing complexity

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent makes the reference voltage line multi-functional by enabling it to serve both normal and abnormal subpixels through dynamic voltage adjustment. Instead of creating separate sensing systems for different subpixel types, the single reference voltage line adapts its voltage level to handle various subpixel conditions. This universal approach maintains manufacturing simplicity while achieving accurate compensation for all subpixel types.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

By changing the voltage parameter of the reference voltage line based on sensed characteristic values, the system can accurately measure both normal and abnormal subpixels using the same hardware infrastructure. This eliminates the need for separate sensing systems and reduces manufacturing complexity while maintaining high measurement precision across all subpixel types.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If fixed reference voltage is applied during operation, then power consumption is low, but image quality deteriorates due to subpixel characteristic changes over time

Engineering Contradiction:

Improvedisplay quality consistencyVSAvoidpower consumption during sensing

Core Design Contradiction:

ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent implements periodic sensing during off-sensing process periods, where the reference voltage is adjusted based on recently sensed characteristic values. This periodic approach allows the system to maintain accurate compensation without continuous high-power operation. The reference voltage is updated at appropriate intervals to track subpixel characteristic changes while minimizing power consumption during non-sensing periods.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system performs preliminary sensing of subpixel characteristic values and adjusts the reference voltage in advance during off-sensing process periods. This preliminary action ensures that the reference voltage is optimized for upcoming display operations, maintaining image quality without requiring continuous adjustment. The compensation is prepared beforehand, allowing normal operation with stable, low power consumption.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11862109B2Display device having analog-to-digital converter for compensating based on subpixel characteristic

Publication Date: 2024.01.02 LG DISPLAY CO LTD

AI summary

A display device includes a reference voltage line electrically connected with a first node and receiving a sensing voltage reflecting a characteristic value of at least one subpixel and an analog-to-digital converter including a second node, receiving the sensing voltage, and outputting a digital value corresponding to the sensing voltage, wherein a voltage level of a driving reference voltage applied to the first node and a voltage level of an analog-to-digital converting reference voltage applied to the second node are changed depending on a level of the sensing voltage, thereby compensating for changes in the characteristic values of subpixels even when abnormal subpixels for which appropriate compensation for changes in characteristic values of subpixels is limited.