Time-Division Gamma Voltage Routing in Display Data Drivers

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Solution Overview

Problem

The size of data drivers in display devices increases significantly with the number of gamma voltage lines, leading to increased power consumption and complexity, as each additional bit of pixel data doubles the number of gamma voltage lines required.

Innovation Solution

The implementation of a data driver that generates 2N gamma voltages and groups them into 2N-M gamma voltage groups, using time-division gamma voltage signals and lines to reduce the number of channels and lines needed, allowing for a spatial and temporal division scheme to select the appropriate gamma voltage for each pixel, thereby reducing the overall size and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the number of gamma voltage lines is increased to support higher bit depth pixel data, then the precision of gamma voltage selection is improved, but the area of the data driver increases

Engineering Contradiction:
Improvegamma voltage selection precisionVSAvoiddata driver area
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent applies time-division multiplexing to periodically transmit different gamma voltage signals through shared lines. During different time periods within a frame, different gamma voltage signals (e.g., first gamma voltage signal during first time period, second gamma voltage signal during second time period) are transmitted through the same physical lines, eliminating the need for separate lines for each voltage level while maintaining precise voltage selection capability

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent makes the gamma voltage lines multi-functional by enabling them to carry multiple different gamma voltage signals sequentially over time. The same physical lines serve multiple purposes by transmitting different voltage levels at different time periods, thus one set of lines replaces what would otherwise require multiple separate lines

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If the number of gamma voltage lines is increased to support higher bit depth pixel data, then the accuracy of data voltage output is improved, but the power consumption increases

Engineering Contradiction:
Improvedata voltage output accuracyVSAvoiddata driver power consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by stationary object

Solution Approach 1:

By using time-division multiplexing, the patent reduces the total number of active voltage lines needed. Instead of having all gamma voltage lines active simultaneously, only one or a few lines are active at any given time period, significantly reducing the power consumption while maintaining the ability to output accurate data voltages through temporal sequencing

Inventive Principle:
Principle #19Periodic action

3Measurement precision

If the number of gamma voltage lines is increased to support higher bit depth pixel data, then the precision of pixel voltage control is improved, but the device complexity increases

Engineering Contradiction:
Improvepixel voltage control precisionVSAvoiddata driver complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces periodic time-division multiplexing control mechanisms that sequentially activate different gamma voltage signals. This temporal sequencing approach replaces the need for complex simultaneous multi-line configurations, reducing structural complexity while maintaining precise pixel voltage control through time-based signal management

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements dynamic signal switching where gamma voltage lines are actively configured for different purposes at different time periods. The system dynamically transitions between transmitting different gamma voltage signals through the same physical infrastructure, replacing static multi-line configurations with dynamic time-multiplexed operation

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3905234A1Data driver and display device including a data driver
Publication Date: 2021.11.03 SAMSUNG DISPLAY CO LTD
  • EP3905234A1 patent drawingFigure 1
  • EP3905234A1 patent drawingFigure 2
  • EP3905234A1 patent drawingFigure 3

AI summary

A data driver includes a gamma voltage generator configured to generate gamma voltages based on a number of data bits of a pixel data; a first digital-to-analog block configured to generate a plurality of time-division gamma voltage signals respectively corresponding to a plurality of gamma voltage groups; a plurality of time-division gamma voltage line groups for transferring the plurality of time-division gamma voltage signals; a second digital-to-analog block configured to select a time-division gamma voltage signal among the time-division gamma voltage signals according to upper bits of the pixel data in each channel; a time-division gamma voltage select block configured to select a gamma voltage according to lower bits of the pixel data in each channel; and an output buffer block configured to output the selected gamma voltage in each channel.