Pixel PWM Bit-Field Distribution to Prevent False Contours
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices using micro LEDs and active matrix-type organic light-emitting diodes suffer from image quality deterioration due to a false contour effect, where luminance is perceived as higher or lower than intended due to separation or connection of emission periods for extended durations.
Innovation Solution
A pulse width modulation (PWM) driving method is employed, where the most significant bit (MSB) of pixel data is scrambled among other bits, and the PWM signal is generated with sub-fields distributed across bit fields, preventing prolonged separation or connection of emission periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional PWM driving is used, then simple control is achieved, but false contour effect occurs causing image quality deterioration
Solution Approach 1:
The PWM signal is divided into multiple sub-fields, each corresponding to different bit fields of pixel data. The MSB bit field is segmented into multiple sub-bit fields that are distributed across different sub-fields, preventing prolonged emission periods and eliminating false contour effects while maintaining controlled complexity through structured segmentation.
2Reliability
If MSB bit field is distributed among sub-fields, then false contour effect is prevented, but control signal complexity increases
Solution Approach 1:
The PWM signal structure is made dynamic by distributing the MSB bit field across multiple sub-fields rather than concentrating it in one continuous period. This dynamic distribution ensures that emission periods are properly separated, maintaining luminance consistency and preventing false contour effects while managing control signal complexity through systematic arrangement.
Data Source
AI summary
Provided is a display device including a pixel array including a plurality of pixels arranged in a matrix. Each pixel includes a pulse width modulation (PWM) circuit and an emission device; a data driver configured to provide pixel data to pixels arranged in a row of the pixel array; and a row driver configured to generate control signals and clock signals for driving the pixel array. The PWM circuit is configured to generate the PWM signal based on the control signals and the clock signals, the PWM signal including a plurality of bit fields respectively corresponding to a plurality of bits of the pixel data. The PWM circuit is further configured to, in a PWM period in which the PWM signal is output, distribute a first bit field of the PWM signal corresponding to a most significant bit (MSB) of the pixel data, among the plurality of bit fields.