OLED Pixel Circuit Single Shift Register Scanning

Solution Overview

Problem

Conventional organic light emitting display devices require multiple shift registers for bidirectional scanning, increasing the size of the scan driving unit and the bezel of the display device.

Innovation Solution

A pixel circuit design that allows for unidirectional and bidirectional scanning using a single shift register, incorporating a storage capacitor, switching units, and transistors to manage scan signals and data signals, enabling flexible scanning directions without increasing the device size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple shift registers are used to perform bidirectional scan, then scanning flexibility is improved, but device size and bezel width increase

Engineering Contradiction:

Improvescanning flexibilityVSAvoiddevice size

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The pixel circuit is designed to support multiple scanning modes (unidirectional top-to-bottom, unidirectional bottom-to-top, and bidirectional scanning) using a single shift register. The circuit includes a storage capacitor, first switching unit, and second switching unit that can be controlled by scan signals from different directions, allowing one circuit to perform multiple functions that previously required separate shift registers

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functionality of multiple shift registers into a single shift register by designing the pixel circuit to receive and process scan signals from both directions. The first switching unit and second switching unit work together to enable the same pixel circuit to be driven by scan signals regardless of their direction of application

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If multiple shift registers are used to perform bidirectional scan, then scanning flexibility is improved, but bezel width increases

Engineering Contradiction:

Improvescanning flexibilityVSAvoidbezel width

Core Design Contradiction:

Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The pixel circuit is designed to support multiple scanning modes (unidirectional top-to-bottom, unidirectional bottom-to-top, and bidirectional scanning) using a single shift register. The circuit includes a storage capacitor, first switching unit, and second switching unit that can be controlled by scan signals from different directions, allowing one circuit to perform multiple functions that previously required separate shift registers

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functionality of multiple shift registers into a single shift register by designing the pixel circuit to receive and process scan signals from both directions. The first switching unit and second switching unit work together to enable the same pixel circuit to be driven by scan signals regardless of their direction of application

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS9412305B2Pixel circuit of an organic light emitting display device and organic light emitting display device including the same

Publication Date: 2016.08.09 SAMSUNG DISPLAY CO LTD

AI summary

A pixel circuit according to an embodiment includes: a capacitor; a first switching unit configured to initialize the capacitor in response to a first scan signal received from a first scan line; a second switching unit configured to receive a second scan signal from a second scan line disposed in a first direction from the first scan line, to receive a third scan signal from a third scan line disposed in a second direction opposite to the first direction from the first scan line, and to be turned on in response to one of the second scan signal and the third scan signal that is activated after the first scan signal is activated to store a data signal in the capacitor; and a driving transistor configured to provide a driving current to an OLED in response to the data signal stored in the capacitor.