LED Backlight Block Control for Display Contrast

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Solution Overview

Problem

Existing display devices using LEDs as backlight sources face limitations in precise control and efficiency due to the selection constraints of LED driver ICs and insufficient local dimming data, which affect the display quality and power consumption.

Innovation Solution

A display device with a backlight unit divided into blocks, each containing multiple light source packages, where a controller generates local dimming data for some blocks and supplements it with additional data from adjacent blocks, allowing for more precise control and improved display quality using the same number of LEDs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the number of light source packages in each block is increased, then the control precision of local dimming is improved, but the selection limitation of LED driver IC is exacerbated

Engineering Contradiction:
Improvecontrol precisionVSAvoidselection limitation
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The backlight unit is divided into multiple blocks, each containing a specific number of light source packages (e.g., 4 packages per block). This segmentation allows the system to work within the driver IC's channel limitations while achieving fine-grained control through the combination of multiple blocks. The segmentation enables precise local dimming by independently controlling each block's brightness based on local image characteristics.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If the number of blocks is increased to improve local dimming control, then the display quality is improved, but the local dimming data becomes insufficient

Engineering Contradiction:
Improvelocal dimming controlVSAvoidlocal dimming data
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

Adjacent blocks are merged into groups (e.g., two 2x2 blocks form a 2x4 group) for which a single local dimming data value is generated. This merging approach reduces the total number of local dimming data points required while maintaining effective local dimming control. The driver IC can efficiently manage the reduced data set while still achieving precise brightness control across all individual blocks through the grouped data structure.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If the same number of LEDs is used as related art, then the device complexity is maintained, but the control precision is insufficient

Engineering Contradiction:
Improvedevice complexityVSAvoidcontrol precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

Different blocks or block groups are assigned different local dimming data values based on their specific local image characteristics. This local quality approach ensures that each region of the display receives optimized brightness control tailored to its content, achieving high control precision without requiring additional LEDs or complex hardware. The system adapts the brightness of each local region independently while using the same total number of LEDs.

Inventive Principle:
Principle #3Local quality

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 enhances display quality by enabling detailed control of luminance and reducing power consumption, overcoming the limitations of LED driver ICs and improving the contrast ratio and resolution while maintaining the same number of LEDs.

Implementation Method 1

The present disclosure relates to a display device, and more particularly, to a display device using a light emitting diode (LED) as a backlight source

Methodology Applied
Scientific EffectLight emitting diode (LED): Light Emitting Diode

Data Source

PatentEP4207174A1Display device
Publication Date: 2023.07.05 LG DISPLAY CO LTD
  • EP4207174A1 patent drawingFigure 1
  • EP4207174A1 patent drawingFigure 2
  • EP4207174A1 patent drawingFigure 3~4

AI summary

A display device (100) according to an exemplary embodiment of the present disclosure includes a backlight unit (120) comprising a plurality of blocks (170) so as to be driven for each divided block (170), each block (170) including a plurality of light source packages (180), a display panel (110) disposed above the backlight unit (120), a controller (160) which outputs local dimming data corresponding to a brightness of some blocks (170) among the plurality of blocks (170), according to an image displayed on the display panel (110) and a backlight unit (BLU) driver (140) which generates additional local dimming data corresponding to a brightness of each of the remaining blocks (170) adjacent to the some blocks (170), among the plurality of blocks (170), using the local dimming data. As a result, the same number of LEDs as the related art is used, but more detailed control is possible so that the display quality is improved.