Backlight Module LED Driver Grouping for Control Timing

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Solution Overview

Problem

The daisy chain system for connecting LED drivers in liquid crystal display backlight modules leads to increased data transmission capacity and management complexity, particularly in multiple division local dimming scenarios, resulting in control complications and image quality degradation.

Innovation Solution

A backlight module configuration with a controller that outputs data and latch signals to LED drivers via grouped data and latch signal lines, reducing wiring connections and allowing simultaneous data writing to LED drivers in units of rows, thereby simplifying control and reducing image quality degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a daisy chain system is used to connect LED drivers, then the wiring amount is reduced, but the data transmission capacity increases and control timing management becomes difficult

Engineering Contradiction:

Improvewiring amountVSAvoidcontrol timing management

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The LED drivers are divided into multiple groups (first groups and second groups), with each group connected to dedicated latch signal lines and data lines from the controller. This segmentation allows independent control of each group, simplifying timing management while maintaining reduced wiring complexity compared to one-to-one connections.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces group-level latch signal lines and data lines as intermediaries between the controller and individual LED drivers. These intermediary connections enable efficient signal distribution to multiple LED drivers simultaneously, reducing the need for extensive point-to-point wiring while maintaining manageable control complexity through structured signal routing.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Illumination intensity

If many LEDs are simultaneously controlled in multiple division local dimming, then the brightness optimization is improved, but the processing delay increases and image quality degrades

Engineering Contradiction:

Improvebrightness optimizationVSAvoidprocessing delay

Core Design Contradiction:

Illumination intensityVSLoss of time

Solution Approach 1:

LED drivers are organized into multiple groups that can be controlled independently with different timing. This allows the system to process and update LED groups in manageable batches rather than all simultaneously, reducing processing delay while maintaining the brightness optimization benefits of local dimming across multiple divisions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The controller prepares and transmits data and latch signals for multiple LED driver groups in advance, organizing the control data before actual LED activation. This preliminary organization of control signals enables efficient simultaneous or near-simultaneous updates across multiple LED groups, reducing overall processing delay while maintaining image quality.

Inventive Principle:

Principle #10Preliminary action

3Measurement precision

If a one-to-one connection is used between controller and LED drivers, then the control precision is improved, but the wiring amount increases

Engineering Contradiction:

Improvecontrol precisionVSAvoidwiring amount

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

Multiple LED drivers within the same group share common latch signal lines and data lines from the controller. This merging of connections maintains precise control over each individual LED driver while significantly reducing the total wiring amount compared to complete one-to-one connections, as signals are efficiently multiplexed across multiple drivers.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The latch signal lines and data lines are designed to serve multiple LED drivers simultaneously, making these connection lines universal rather than dedicated to single drivers. This multi-functionality allows the same physical connections to control multiple LED drivers, reducing wiring quantity while maintaining the ability to precisely control each driver through group-based addressing and timing.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10908456B2Backlight module for liquid crystal display device

Publication Date: 2021.02.02 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA

AI summary

A backlight module for a liquid crystal display includes: LEDs; LED drivers; a controller that outputs data and the latch signal to the LED drivers; data lines for transmitting the data; and latch signal lines for transmitting the latch signal. The latch signal lines are wired according to each of a plurality of first groups obtained by dividing LED drivers. The data lines are wired according to each of a plurality of second groups, which are constructed with a collection of at least one LED driver selected from each of the plurality of first groups without duplication, and each data line is commonly connected to at least one LED belonging to the corresponding second group.