Matrix Display Selectors for Continuous Current Luminance

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Solution Overview

Problem

Existing display devices with a matrix arrangement of light emitting elements face challenges in achieving high luminance without increasing the number of drive transistors, as methods that reduce wiring lines and improve aperture ratio, such as time division emission, disrupt continuous electric current flow and are not suitable for increasing luminance.

Innovation Solution

A display device configuration with a data line, first and second pixel circuits, and light emitting elements, where selectors are used to alternate the selection of light emitting elements in each sub-frame, ensuring continuous current flow and increased luminance without increasing transistor count.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple light emitting elements are coupled to one pixel circuit with time division emission, then the number of wiring lines is reduced and aperture ratio is improved, but continuous electric current flow is disrupted and luminance cannot be increased

Engineering Contradiction:

Improveaperture ratioVSAvoidluminance

Core Design Contradiction:

Area of stationary objectVSIllumination intensity

Solution Approach 1:

The display panel is divided into multiple sub-frames within one frame period, with each sub-frame dedicated to driving a specific light emitting element. This segmentation allows each light emitting element to receive continuous current throughout its assigned sub-frame while maintaining the multiplexed wiring structure that improves aperture ratio.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent pre-assigns specific time slots (sub-frames) to each light emitting element before the frame period begins. This preliminary timing arrangement ensures that current can flow continuously to each element during its designated sub-frame without interruption, enabling luminance enhancement while maintaining the reduced wiring configuration.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If multiple light emitting elements are coupled to one pixel circuit, then the number of drive transistors is reduced, but switching between elements every sub-frame prevents continuous current flow

Engineering Contradiction:

Improvenumber of drive transistorsVSAvoidcontinuous current flow

Core Design Contradiction:

Device complexityVSDuration of action of moving object

Solution Approach 1:

The frame period is segmented into multiple sub-frames, with each sub-frame assigned to a specific light emitting element. This temporal segmentation allows the pixel circuit to maintain continuous current flow to the active element throughout its entire sub-frame duration, rather than switching elements mid-sub-frame, thereby preserving both low transistor count and continuous current capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent ensures continuous current flow to each light emitting element throughout its assigned sub-frame by dedicating the entire sub-frame duration to that element. This eliminates switching interruptions within the current flow path, maintaining continuous useful action (light emission) while keeping the pixel circuit simple with minimal transistors.

Inventive Principle:

Principle #20Continuity of useful action

3Duration of action of moving object

If one-to-one pixel circuit and light emitting element arrangement is used, then continuous current flow is maintained, but the number of transistors increases and aperture ratio decreases

Engineering Contradiction:

Improvecontinuous current flowVSAvoidnumber of transistors

Core Design Contradiction:

Duration of action of moving objectVSDevice complexity

Solution Approach 1:

Each pixel circuit is designed to serve multiple light emitting elements across different sub-frames, making it multi-functional. The same pixel circuit infrastructure handles multiple elements sequentially, reducing the total transistor count compared to one-to-one pairing, while still maintaining continuous current flow to the active element during its sub-frame.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces a time dimension (sub-frames) to resolve the contradiction. Instead of spatial one-to-one mapping, multiple elements share the same pixel circuit through temporal multiplexing, reducing device complexity while maintaining continuous current flow in the time domain for each element.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS11562694B2Display device and electronic device having selectors configured to select light emitting elements arranged in a matrix

Publication Date: 2023.01.24 SEIKO EPSON CORP

AI summary

A pixel circuit 16(n) and a pixel circuit 16(n−1) acquire a data signal from a data line 14. A selector 30(n) supplies the data signal acquired from the pixel circuit 16(n) to a light emitting element selected from the light emitting elements 18(n−1), 18(n), and 18(n+1). A selector 30(n−1) can select at least the light emitting element 18(n−1), and supplies the data signal acquired from the pixel circuit 16(n−1) to the selected destination. In a sub-frame B, the selector 30(n) selects the light emitting elements 18(n) and 18(n+1), and the selector 30(n−1) selects the light emitting element 18(n−1). In a sub-frame A, the selector 30(n) selects the light emitting elements 18(n−1) and 18(n).