OLED Signal Line Sharing Data and Sensing Signals

Solution Overview

Problem

In organic light-emitting display (OLED) devices, the crystallization process for polysilicon thin film transistors can result in non-uniform threshold voltages between pixels due to unstable laser power, leading to image quality issues, and existing solutions that compensate for these voltages require additional transistors and signal lines, which reduce the aperture ratio and lifespan of the device.

Innovation Solution

An OLED device design where a single signal line is shared between adjacent columns of pixels to transmit both data and sensing signals, allowing the controller to generate compensated data signals based on sensed threshold voltages, thereby maintaining uniform brightness without the need for additional transistors and signal lines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If additional transistors and signal lines are added to compensate for threshold voltage variations, then image quality uniformity is improved, but aperture ratio is reduced and device lifespan is shortened

Engineering Contradiction:

Improvethreshold voltage uniformityVSAvoidaperture ratio

Core Design Contradiction:

Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The patent applies multi-functionality by enabling signal lines to serve dual purposes: transmitting data signals during normal operation and transmitting sensing signals during sensing periods. This allows threshold voltage compensation without adding dedicated sensing signal lines, thereby maintaining aperture ratio while achieving image quality uniformity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements periodic action by alternating between data signal transmission and sensing signal transmission on the same signal lines at different time periods. During sensing periods, sensing signals are transmitted to detect threshold voltages, and during normal periods, data signals are transmitted for display operation, enabling compensation without continuous additional hardware.

Inventive Principle:

Principle #19Periodic action

2Manufacturing precision

If additional transistors and signal lines are added to compensate for threshold voltage variations, then image quality uniformity is improved, but device complexity is increased

Engineering Contradiction:

Improvethreshold voltage uniformityVSAvoidcircuit configuration

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by enabling signal lines to serve dual purposes: transmitting data signals during normal operation and transmitting sensing signals during sensing periods. This allows threshold voltage compensation without adding dedicated sensing signal lines, thereby maintaining aperture ratio while achieving image quality uniformity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements periodic action by alternating between data signal transmission and sensing signal transmission on the same signal lines at different time periods. During sensing periods, sensing signals are transmitted to detect threshold voltages, and during normal periods, data signals are transmitted for display operation, enabling compensation without continuous additional hardware.

Inventive Principle:

Principle #19Periodic action

3Manufacturing precision

If laser power is stabilized during crystallization, then threshold voltage uniformity is improved, but manufacturing complexity is increased

Engineering Contradiction:

Improvethreshold voltage uniformityVSAvoidcrystallization process

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies feedback by sensing the threshold voltages of thin film transistors and using this information to compensate for variations. The sensing signals detect actual threshold voltage values, and this feedback is used to adjust data signals accordingly, correcting for crystallization process variations without needing to control the laser power during manufacturing.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS9489895B2Organic light-emitting display device with signal lines for carrying both data signal and sensing signal

Publication Date: 2016.11.08 LG DISPLAY CO LTD

AI summary

An organic light-emitting display device having a signal line that is shared by a first column of pixels and a second column of pixels to transmit a data signal and a sensing signal. The organic light-emitting display device includes a plurality of columns of pixels, and a plurality of signal lines extending between the plurality of columns of pixels. Each of the plurality of signal lines is configured to transmit a data signal from a data driver to the first column of pixels at first times. The data signals control the operation of an organic light-emitting element in the first column of pixels. The same signal line transmits a sensing signal from the second column of pixels to the data driver at second times. The sensing signal represents a variable property of an electrical component in a pixel of the second column of pixels.