Pixel Circuit Integrating Touch Control and Threshold Compensation

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Solution Overview

Problem

Current OLED display panels face challenges in integrating touch control functions seamlessly with pixel circuits, leading to complex and costly manufacturing processes, and issues with threshold voltage shift affecting display uniformity.

Innovation Solution

A pixel circuit design that incorporates a display unit with a light-emitting element, driving transistor, storage capacitor, power switch module, precharging module, and compensation module, along with a touch control unit featuring an initialization module, touch control module, and output control module, which operates in three phases to maintain conduction states and compensate data signals, allowing for simultaneous light-emitting display and touch control without increasing circuit complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If display panel and TSP are fabricated separately and then jointed together, then each component can be optimized independently, but the manufacturing process becomes complex and costly, and the final product is heavier and thicker

Engineering Contradiction:
Improvecomponent optimizationVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the touch control unit directly into the pixel circuit structure, combining the display panel and TSP into a single fabricated unit. This eliminates the need for separate fabrication and joining processes, reducing manufacturing complexity while maintaining the ability to optimize both display and touch control functions together through shared circuit elements like transistors and capacitors

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If display panel and TSP are jointed together after separate fabrication, then each component can be optimized independently, but the final product is heavier and thicker

Engineering Contradiction:
Improvecomponent optimizationVSAvoiddisplay panel weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

By integrating the touch control unit into the pixel circuit, the patent eliminates separate TSP layers and bonding structures, reducing the overall weight of the display assembly while maintaining independent optimization capabilities for both display and touch control functions through shared circuit elements

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If display panel and TSP are jointed together after separate fabrication, then each component can be optimized independently, but the final product is thicker

Engineering Contradiction:
Improvecomponent optimizationVSAvoiddisplay panel thickness
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The integration of touch control unit into the pixel circuit structure eliminates the need for separate TSP bonding layers and intermediate structures, thereby reducing the overall thickness of the display panel while preserving the ability to independently optimize display and touch control performance through shared circuit design

Inventive Principle:
Principle #5Merging (Combining)

4Ease of manufacture

If touch control unit is integrated into pixel circuit, then manufacturing process is simplified and cost is reduced, but circuit complexity increases

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidcircuit complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent employs multiple transistors and capacitors that serve dual functions: some transistors act as switches for both display signal routing and touch control signal acquisition, while capacitors store charges for both display pixel operation and touch control signal processing. This multi-functionality reduces the need for separate dedicated components, thereby simplifying manufacturing while managing circuit complexity through shared elements

Inventive Principle:
Principle #6Universality (Multi-functionality)

5Ease of manufacture

If touch control unit is integrated into pixel circuit, then manufacturing cost is reduced, but circuit complexity increases

Engineering Contradiction:
Improvemanufacturing cost reductionVSAvoidcircuit complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

By designing transistors and capacitors to perform multiple functions simultaneously - serving both display pixel operations and touch control signal processing - the patent reduces the total component count and simplifies manufacturing processes, thereby lowering production costs while keeping circuit complexity manageable through efficient resource sharing

Inventive Principle:
Principle #6Universality (Multi-functionality)

6Use of energy by moving object

If compensation module operates without maintaining conduction state, then power consumption is reduced, but threshold voltage shift compensation is ineffective

Engineering Contradiction:
Improvepower consumptionVSAvoidthreshold voltage compensation effectiveness
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The precharging module activates the compensation module in advance by establishing a conduction state through the sixth transistor before the compensation operation begins. This preliminary action ensures that the compensation module is ready to effectively compensate for threshold voltage shifts when needed, while allowing the system to return to a lower power state afterward, thus balancing compensation effectiveness with power consumption

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3188172B1Pixel circuit and drive method thereof, and display device
Publication Date: 2020.09.02 BOE TECHNOLOGY GROUP CO LTD
  • EP3188172B1 patent drawingFigure 1~2
  • EP3188172B1 patent drawingFigure 3~4
  • EP3188172B1 patent drawingFigure 5~6

AI summary

Provided is a pixel circuit, a driving method thereof, and a display apparatus. The pixel circuit comprises a display unit (10) and a touch control unit (20), wherein a precharging module (13) in the display unit (10) is configured to charge a control terminal of a driving transistor (M2), and maintain the state under the effect of a storage capacitor (C); a compensation module (14) is configured to compensate a data signal and write the compensated data signal into the storage capacitor (C); a power switch module (12) is configured to input an operating voltage into the driving transistor (M2) after the data signal is written into the storage capacitor (C); the driving transistor (M2) is configured to use the data signal stored in the storage capacitor (C) to drive a light-emitting element (11) to emit light; an initialization module (21) in the touch control unit (20) is configured to initialize a touch control module (22) while the precharging module (13) is operating; a touch control module (22) is configured to collect touch control signals in corresponding regions; a output control module (23) is configured to close an output path to output the touch control signals collected by the touch control module (22) while the compensation module (14) is operating. The pixel circuit can compensate the threshold voltage drift, and integrate a touch control module into the pixel circuit, which can simplify operation and manufacturing process.