Display Device Using Pulse Width and Amplitude Modulation for Color Shift Control
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Solution Overview
Problem
Conventional pulse-width modulation in display technology faces challenges such as short charging time, high data transmission bandwidth requirements, and inability to support high resolution, leading to color shifts and inefficiencies.
Innovation Solution
A display device and driving method utilizing a timing controller, gate driving units, and source driving units to generate pulse width modulation and pulse amplitude modulation signals, controlling light-emitting duration and driving current of sub-pixels, which converts image grayscale data into timing control signals to manage sub-pixel charging and current control, thereby avoiding color shifts and supporting high resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If conventional pulse-width modulation is used for driving light-emitting diodes, then the charging time is short and data transmission bandwidth is high, but the sub-pixel charging time is insufficient and color shifts occur
Solution Approach 1:
The patent segments the grayscale control into two independent parts: pulse width modulation for binary on/off control and pulse amplitude modulation for brightness control. This segmentation allows the sub-pixel to charge fully during the on-period without time constraints, eliminating color shifts while maintaining grayscale accuracy.
Solution Approach 2:
The patent adds a new dimension to grayscale control by introducing pulse amplitude modulation alongside pulse width modulation. Instead of controlling grayscale solely through time (pulse width), the invention incorporates amplitude as an additional control dimension, allowing full charging time while achieving grayscale through combined PWM-PAM control.
2Productivity
If conventional pulse-width modulation is used, then the charging time is short, but the data transmission bandwidth requirements become high
Solution Approach 1:
The patent extracts the brightness control function from the time-domain PWM signal and places it in the amplitude-domain PAM signal. This extraction reduces the data burden on PWM channels, allowing longer sub-pixel charging times without increasing bandwidth requirements, thereby improving data transmission efficiency.
3Manufacturing precision
If conventional pulse-width modulation is used, then the system cannot support high resolution, but the charging time remains short
Solution Approach 1:
The patent changes the control parameters from solely time-based PWM to a combination of time-based PWM and amplitude-based PAM. This parameter change enables high resolution by providing more precise grayscale control through amplitude variation, while simultaneously allowing longer charging times since amplitude control compensates for the extended duration.
Data Source
AI summary
The present application provides a display device and a driving method of the display device. A pixel circuit controls a light-emitting duration of a light-emitting element according to a pulse width modulation scan signal, a pulse width modulation data signal, and a pulse width modulation control signal, and controls an amount of a driving current of the light-emitting element according to a pulse amplitude modulation scan signal and a pulse amplitude modulation data signal.