Backlight Module Cascaded Voltage Comparators MLED Drive Chip

Solution Overview

Problem

In Micro/Mini Light-Emitting Diode (MLED) backlights, manufacturing errors lead to varying voltages required for LEDs, causing a high initial drive voltage that results in excessive power consumption and temperature rise for the drive chip.

Innovation Solution

A backlight module with cascaded voltage comparators and a voltage adjustment module that connects light-emitting units to a shared initial drive voltage, allowing voltage comparators to detect and adjust the drive voltage to prevent excessive voltage at the control terminal of the drive chip, thereby reducing power consumption and temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the initial drive voltage is increased to ensure all LEDs achieve the required brightness, then the brightness uniformity of LEDs is improved, but the power consumption and temperature of the drive chip increase

Engineering Contradiction:

Improvebrightness uniformityVSAvoidpower consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the voltage control by introducing multiple voltage comparison stages (first stage, second stage, third stage) with different reference voltages. Each stage handles a specific voltage range, allowing precise control without excessive voltage application to the drive chip.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter of reference voltage across different stages. The first stage uses a first reference voltage, the second stage uses a second reference voltage, and the third stage uses a third reference voltage, enabling adaptive voltage adjustment based on actual LED requirements.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the initial drive voltage is increased to ensure all LEDs achieve the required brightness, then the brightness uniformity of LEDs is improved, but the temperature of the drive chip increases

Engineering Contradiction:

Improvebrightness uniformityVSAvoiddrive chip temperature

Core Design Contradiction:

Manufacturing precisionVSTemperature

Solution Approach 1:

The patent segments the voltage control by introducing multiple voltage comparison stages (first stage, second stage, third stage) with different reference voltages. Each stage handles a specific voltage range, allowing precise control without excessive voltage application to the drive chip.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter of reference voltage across different stages. The first stage uses a first reference voltage, the second stage uses a second reference voltage, and the third stage uses a third reference voltage, enabling adaptive voltage adjustment based on actual LED requirements.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If a single high initial drive voltage is applied to all light-emitting units, then all LEDs can achieve the required brightness despite manufacturing errors, but the device complexity increases due to multiple voltage comparison stages

Engineering Contradiction:

ImproveLED brightness assuranceVSAvoidvoltage control circuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic voltage adjustment through cascaded voltage comparison stages. The voltage comparison module dynamically selects appropriate reference voltages based on actual LED voltage requirements, adapting the control strategy in real-time rather than using a fixed high voltage.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms where the voltage comparison module continuously monitors the voltage across light-emitting units and adjusts the drive voltage accordingly. The cascaded stages provide hierarchical feedback control, ensuring brightness uniformity while preventing excessive voltage application.

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution effectively reduces the power consumption and temperature of the drive chip by ensuring the drive voltage is optimized, ensuring normal operation and light emission of the light-emitting units while preventing overheating.

Implementation Method 1

a voltage comparison module, configured to compare a drive voltage with a reference voltage to generate an adjusted drive voltage signal

Methodology Applied

Scientific EffectVoltage comparison: Electric Field

Data Source

PatentUS20230317024A1Backlight module and display device

Publication Date: 2023.10.05 TCL CHINA STAR OPTOELECTRONICS TECHNOLOGY CO LTD

AI summary

The present application discloses a backlight module and a display device. The backlight module includes a plurality of light-emitting units, a plurality of drive chips, a plurality of cascaded voltage comparators, and a voltage adjustment module. The light-emitting unit connected to a control terminal of a same drive chip is connected with a same initial drive voltage. The plurality of cascaded voltage comparators output an adjustment voltage in a N-th stage based on a preset voltage and a plurality of to-be-detected voltages. The voltage adjustment module is configured to adjust the initial drive voltage based on the adjustment voltage in the N-th stage.