Backlight Luminance Control via Time Division Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid crystal panel display apparatuses using the RGBW display method face challenges in maintaining image quality due to fluctuations in backlight luminance control, leading to flickering and loss of linearity in luminance, when trying to finely control backlight luminance by increasing the bit number of PWM signals.
Innovation Solution
The implementation of a time division control unit that converts a high-bit luminance control signal into lower-bit signals with specific pulse widths, maintaining the period of the PWM signal and ensuring the backlight driver can respond properly, thereby preventing flickering and maintaining linearity in luminance control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the bit number of PWM signals is increased to finely control backlight luminance, then luminance control precision is improved, but the period of PWM signal is extended causing flickering and loss of linearity
Solution Approach 1:
The patent segments the high-bit luminance control signal into multiple lower-bit signals distributed across different time slots. Instead of using a single high-resolution PWM signal that extends the period, the control signal is divided into multiple segments (e.g., four 8-bit signals from a 10-bit input), each transmitted in sequential time slots. This segmentation maintains the original PWM period while achieving fine luminance control through temporal distribution of control data.
Solution Approach 2:
The patent implements periodic transmission of segmented luminance control signals. The divided control signals are transmitted in repeated cycles across multiple time slots, creating a periodic pattern that maintains synchronization with the original PWM frequency. This periodic action ensures the backlight driver receives control information at the correct rhythm, preventing flickering while delivering high-precision luminance control data.
2Measurement precision
If the bit number of PWM signals is increased to achieve accurate luminance control, then luminance control accuracy is improved, but image quality deteriorates due to flickering
Solution Approach 1:
The patent segments the high-bit luminance control signal into multiple lower-bit signals distributed across different time slots. Instead of using a single high-resolution PWM signal that extends the period, the control signal is divided into multiple segments (e.g., four 8-bit signals from a 10-bit input), each transmitted in sequential time slots. This segmentation maintains the original PWM period while achieving fine luminance control through temporal distribution of control data.
Solution Approach 2:
The patent introduces an intermediary processing stage that converts the high-bit luminance control signal into segmented lower-bit signals. This intermediary conversion process acts as a mediator between the high-precision control requirement and the backlight driver's operational constraints, transforming the control signal format to be compatible with existing drivers while preserving accuracy through temporal multiplexing.
3Measurement precision
If the bit number of PWM signals is increased to control backlight luminance, then luminance resolution is improved, but linearity in luminance control is lost
Solution Approach 1:
The patent segments the high-bit luminance control signal into multiple lower-bit signals distributed across different time slots. Instead of using a single high-resolution PWM signal that extends the period, the control signal is divided into multiple segments (e.g., four 8-bit signals from a 10-bit input), each transmitted in sequential time slots. This segmentation maintains the original PWM period while achieving fine luminance control through temporal distribution of control data.
Solution Approach 2:
The patent implements dynamic time-division multiplexing where the segmented control signals are actively managed across different time slots. The system dynamically allocates control data to appropriate time slots and manages the temporal sequence of signal transmission. This dynamic approach ensures that the backlight driver receives properly sequenced control information, maintaining linearity in luminance control while achieving high resolution through the segmented signal structure.
Data Source
AI summary
Provided are a display apparatus and an illumination apparatus including: a light source; a time division control unit that performs a time division operation on a value represented by a first luminance control signal of a first bit number for controlling luminance of the light source to generate second luminance control signals each having a second bit number that is smaller than the first bit number and generates third luminance control signals each having a pulse width that corresponds to one of the values represented by the second luminance control signals; and a drive unit that generates drive signals for causing the light source to emit light on the basis of the third luminance control signals and supplies the drive signals to the light source.