Asynchronous LCD Backlight Control for Lower Power and Less Flicker

Solution Overview

Problem

Current LCD systems face issues with power inefficiency and flicker due to the synchronous control of backlights with video frames, leading to suboptimal backlight power levels and inconsistent LCD and LED response speeds.

Innovation Solution

Implementing asynchronous control of the backlight directly from the display engine, allowing for higher refresh rates and independent adjustment of backlight levels to align with LCD response times, using a display engine cache and lookup tables to determine optimal power levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If synchronous control of backlight with video frames is used, then the system maintains simple control architecture, but power consumption increases and flicker occurs

Engineering Contradiction:

Improvecontrol architectureVSAvoidpower consumption

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent segments the control architecture by separating backlight control from the synchronous video frame control. The display engine is divided into independent components: one handling video data to TCON and another handling backlight control data to the backlight controller. This segmentation allows asynchronous operation of the backlight, enabling it to be updated at optimal intervals rather than being locked to the video frame rate, thereby reducing unnecessary power consumption while maintaining architectural clarity through functional separation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic control of the backlight by allowing it to operate independently from the fixed video frame rate. The display engine can adjust backlight levels at variable refresh rates based on actual content requirements and LCD response times. This dynamic approach enables the system to reduce backlight power consumption during periods when full brightness is not needed, while the flexible timing prevents flicker by synchronizing backlight changes with LCD pixel response capabilities.

Inventive Principle:

Principle #15Dynamics

2Device complexity

If synchronous control of backlight with video frames is used, then the control timing is simplified, but flicker occurs due to mismatched response speeds

Engineering Contradiction:

Improvecontrol timingVSAvoidflicker

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic control of the backlight by allowing it to operate independently from the fixed video frame rate. The display engine can adjust backlight levels at variable refresh rates based on actual content requirements and LCD response times. This dynamic approach enables the system to reduce backlight power consumption during periods when full brightness is not needed, while the flexible timing prevents flicker by synchronizing backlight changes with LCD pixel response capabilities.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms where the display engine monitors LCD pixel response times and adjusts backlight update timing accordingly. By measuring the actual response characteristics of the LCD and using this information to control backlight timing, the system ensures that backlight changes are completed before the next frame update, preventing visible flicker. This feedback-driven approach optimizes the balance between control simplicity and flicker prevention.

Inventive Principle:

Principle #23Feedback

3Stability of the object's composition

If backlight is updated at video frame rate, then the system maintains consistent timing, but LCD and LED response speed mismatch causes suboptimal performance

Engineering Contradiction:

Improvetiming consistencyVSAvoidresponse speed alignment

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent implements dynamic control of the backlight by allowing it to operate independently from the fixed video frame rate. The display engine can adjust backlight levels at variable refresh rates based on actual content requirements and LCD response times. This dynamic approach enables the system to reduce backlight power consumption during periods when full brightness is not needed, while the flexible timing prevents flicker by synchronizing backlight changes with LCD pixel response capabilities.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the timing parameters of backlight updates by decoupling them from the fixed video frame rate. Instead of updating the backlight at every video frame, the system adjusts the backlight refresh rate to match LCD response characteristics. This parameter change allows the backlight to be updated at optimal intervals, improving the alignment between LCD and LED response speeds while maintaining sufficient timing consistency for stable display operation.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12431100B2Asynchronous control of a backlight for a liquid crystal display

Publication Date: 2025.09.30 INTEL CORP

AI summary

Particular embodiments described herein provide for an electronic device that includes a liquid crystal display, a backlight for the liquid crystal display, a timing controller (TCON), and a display engine located outside of the TCON, where the display engine asynchronously sends image data to the TCON and backlight control data to the backlight.