Dynamic Loop Current Control for Display Data Drivers

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Solution Overview

Problem

Existing display devices face high power consumption due to fixed bias currents in data drivers and inefficient data transmission methods, such as LVDS, which increase power usage for reliability, leading to suboptimal performance in driving pixels and displaying video data.

Innovation Solution

A method to analyze input image data and dynamically control the current used for driving data lines, employing a current controller to adjust the loop current based on image data toggling, reducing power consumption while maintaining transmission reliability by selecting appropriate current values and terminating resistances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If LVDS interface method is used to increase reliability of data transmission, then transmission reliability is improved, but power consumption increases

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic current control in the data driver by analyzing image data characteristics (full-screen update, partial update, static image) and adjusting the loop current accordingly. The current controller dynamically switches between different current levels (first loop current for high reliability needs, second loop current for power saving) based on real-time display content analysis, making the system adaptive rather than static

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical parameter (loop current) of the data driver based on image data analysis. By detecting display mode and image characteristics, the system adjusts current magnitude and termination resistance values to optimize the balance between transmission reliability and power consumption, transforming a fixed-parameter system into a variable-parameter system

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If fixed bias current is used in data driver buffers, then circuit simplicity is maintained, but power consumption increases

Engineering Contradiction:
Improvecircuit simplicityVSAvoidpower consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The data driver performs self-adjustment by automatically analyzing its own operating conditions (image data characteristics, display mode) and controlling its internal current consumption accordingly. The current controller within the data driver enables the circuit to serve itself by making autonomous decisions about power management without external intervention

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent transforms the static bias current into a dynamic controllable parameter. By introducing the current controller that adjusts loop current based on image analysis, the system maintains circuit simplicity while enabling adaptive power management through dynamic current adjustment rather than complex circuit reconfiguration

Inventive Principle:
Principle #15Dynamics

3Reliability

If current is increased to drive data lines, then transmission reliability is improved, but power consumption increases

Engineering Contradiction:
Improvesignal transmission reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies partial action by using high current (first loop current) only when necessary for specific display modes or image characteristics, and low current (second loop current) for other conditions. This avoids excessive current usage in all scenarios while ensuring sufficient current is provided when transmission reliability is critical

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system dynamically changes current parameters based on image data analysis, adjusting loop current magnitude and termination resistance to match actual transmission needs. This transforms the energy-loss problem into an optimized parameter selection problem where current and resistance are adjusted to achieve minimum necessary power consumption for acceptable reliability

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3040973B1Display device
Publication Date: 2023.09.06 LG DISPLAY CO LTD
  • EP3040973B1 patent drawingFigure 1
  • EP3040973B1 patent drawingFigure 2~3
  • EP3040973B1 patent drawingFigure 4~5

AI summary

A display device includes a differential signaling driver configured to produce a differential signal using a variable current, first and second signal lines configured to maintain a loop current in response to a signal output by the differential signaling driver, a current controller configured to reduce the variable current when one of low data and high data of image data is equal to or greater than a critical value, and a receiving unit configured to receive the differential signal through the first and second signal lines.