OLED Driver IC Pin Reduction via Shared Line Multiplexing

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Solution Overview

Problem

The existing external compensation methods for OLED displays require a large number of I/O pins in the driver IC due to the need for separate source and sensing lines for each column of sub-pixels, increasing the cost and complexity of the driver IC.

Innovation Solution

The method involves sharing source and sensing lines between adjacent sub-pixels, allowing each line to function alternately as both a source and sensing line, reducing the total number of lines required and pin count in the driver IC, and utilizing a multiplexer to further reduce the pin count by enabling communication through fewer I/O pins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate source and sensing lines are used for each column of sub-pixels, then external compensation can be performed effectively, but the number of I/O pins in the driver IC increases significantly

Engineering Contradiction:

Improveexternal compensation effectivenessVSAvoidnumber of I/O pins

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the source line and sensing line functions into a single shared line. The same physical line is used alternately as a source line for programming devices and as a sensing line for reading device characteristics, eliminating the need for separate dedicated lines for each function.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements periodic switching between source and sensing modes. During first periods, the shared line operates as a source line to program devices in sub-pixels; during second periods, the same line switches to sensing mode to read device characteristics. This time-division multiplexing enables one line to perform both functions sequentially.

Inventive Principle:

Principle #19Periodic action

2Adaptability or versatility

If a large number of lines are used for data display and external compensation, then all sub-pixels can be controlled, but the cost of the driver IC increases

Engineering Contradiction:

Improvecoverage of sub-pixel controlVSAvoiddriver IC cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent makes each line universal by enabling it to serve multiple functions: it can act as a source line for programming, a sensing line for reading, and communicate with different columns of sub-pixels at different times. This multi-functionality reduces the total number of lines required from 2N to N.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces dynamic reconfiguration of line functions through time-division multiplexing. The lines are not statically assigned to single functions but dynamically switch roles based on operational requirements, allowing the same physical infrastructure to support multiple operational modes.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10388207B2External compensation method and driver IC using the same

Publication Date: 2019.08.20 NOVATEK MICROELECTRONICS CORP

AI summary

An external compensation method for devices in a panel which comprises a plurality of sub-pixels, includes programming a first device in a first sub-pixel among the plurality of sub-pixels via a first line and sensing the first device via a second line during a first period; and programming a second device in a second sub-pixel among the plurality of sub-pixels via the second line and sensing the second device via the first line or a third line during a second period.