Transient Capacitive Coupling for Display Panel Control

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Solution Overview

Problem

Existing active matrix display panels face a reduction in maximum luminance due to the need for alternating emission and depolarization periods, which requires costly adaptations in address electrode control means and reduces overall emission time.

Innovation Solution

The use of capacitive coupling to reverse voltages at emitter or valve terminals without reversing address signals, allowing for voltage jumps to be applied transiently to control terminals, eliminating the need for costly address electrode control means and enabling simultaneous control of select and clamping switches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If voltage reversal is implemented at emitter terminals during depolarization periods, then modulator polarization is compensated, but maximum luminance is reduced due to reduced emission time

Engineering Contradiction:

Improvemodulator polarization compensationVSAvoidmaximum luminance

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent implements dynamic control of the modulator by alternating between emission mode (forward bias) and depolarization mode (reverse bias) within each frame period. The modulator is dynamically switched between conducting and blocking states to compensate polarization drift while maintaining display performance.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies periodic voltage reversal to the modulator gate terminal at specific intervals (during designated depolarization periods) to compensate for polarization effects. This periodic action maintains modulator reliability without continuously reducing emission time.

Inventive Principle:

Principle #19Periodic action

2Reliability

If address signals are reversed during depolarization periods, then voltage reversal at emitter terminals is achieved, but costly adaptations in address electrode control means are required

Engineering Contradiction:

Improvevoltage reversal at emitter terminalsVSAvoidaddress electrode control means

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a clamping terminal as an intermediary element that decouples the address signal path from the voltage reversal function. The clamping terminal acts as a mediator that enables voltage reversal at the emitter terminals through local circuit action rather than through the address signal path.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the voltage control function into separate components: the address signal path remains dedicated to image data transmission, while a separate clamping terminal and switch mechanism handle the voltage reversal function. This segmentation eliminates the need for costly adaptations in address electrode control means.

Inventive Principle:

Principle #1Segmentation

3Reliability

If depolarization periods are inserted between emission periods, then modulator polarization is compensated, but overall emission time is reduced

Engineering Contradiction:

Improvemodulator polarization compensationVSAvoidemission time

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent applies partial voltage reversal during specific portions of the frame period (depolarization periods) rather than continuous reversal. This partial action is sufficient to compensate polarization effects while minimizing the impact on overall emission time.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the timing parameters of depolarization periods to occur during intervals that minimize impact on emission time. By optimizing when depolarization occurs within the frame structure, the patent maintains modulator reliability while preserving maximum luminance output.

Inventive Principle:

Principle #35Parameter changes

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 method enhances image display quality and luminance by allowing specific depolarization operations based on emission signals, reducing the need for additional electrodes and maintaining efficient emission periods while depolarizing modulators.

Implementation Method 1

the control terminal of the circuit is coupled to an address electrode via a coupling capacitor

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentUS8094101B2Display panel and control method using transient capacitive coupling

Publication Date: 2012.01.10 INTERDIGITAL CE PATENT HOLDINGS SAS

AI summary

Panel comprising display drivers which, each 1″′, comprise a select switch and a clamping switch which are controlled by the same select electrode, and a coupling capacitor for transiently coupling the control terminal of this circuit C to an address electrode. A control method comprising emission periods and depolarization periods, where all the address signals have the same polarity. The invention makes it possible in particular to use conventional and inexpensive means of controlling the address electrodes.