Pixel Circuit With Dual Current-Duration Control for Low-Gray Brightness
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Solution Overview
Problem
Existing display technologies face issues with strobing and eye damage due to direct current (DC) dimming at low gray scale brightness, and struggle to accurately and stably present low gray scale brightness.
Innovation Solution
A pixel circuit with a current control circuit and duration control circuit that adjusts the amplitude and duration of the drive current based on data and control signals, ensuring high uniformity and stability of emission brightness and chromaticity coordinates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If DC dimming is used for brightness adjustment, then the display device can achieve brightness control, but it causes strobing and eye damage at low gray scale brightness
Solution Approach 1:
The patent applies periodic action by using pulse width modulation (PWM) to control the light-emitting element. Instead of using direct current (DC) dimming that causes strobing, the invention modulates the light emission in periodic pulses with varying duty cycles. The duration control circuit adjusts the on-time and off-time of the light-emitting element periodically, achieving brightness control without the harmful strobing effects of DC dimming at low gray scales.
2Illumination intensity
If DC dimming is used for brightness adjustment, then the display device can achieve brightness control, but it causes eye damage at low gray scale brightness
Solution Approach 1:
The patent applies periodic action by using pulse width modulation (PWM) to control the light-emitting element. Instead of using direct current (DC) dimming that causes strobing, the invention modulates the light emission in periodic pulses with varying duty cycles. The duration control circuit adjusts the on-time and off-time of the light-emitting element periodically, achieving brightness control without the harmful strobing effects of DC dimming at low gray scales.
3Device complexity
If conventional pixel circuits are used, then the circuit structure is simple, but they cannot accurately and stably present low gray scale brightness
Solution Approach 1:
The patent applies segmentation by dividing the pixel circuit into two independent functional modules: a current control circuit that regulates the amplitude of drive current, and a duration control circuit that regulates the time duration of current flow. This segmentation allows precise independent control of current magnitude and time, enabling accurate low gray scale brightness presentation without requiring excessive overall circuit complexity.
Solution Approach 2:
The patent applies dynamics by implementing dynamic control of both current amplitude and time duration through dedicated control circuits. The current control circuit dynamically adjusts the drive current amplitude based on input signals, while the duration control circuit dynamically adjusts the on-time of the light-emitting element. This dynamic dual-parameter control enables precise presentation of low gray scale brightness levels that static conventional circuits cannot achieve.
Data Source
AI summary
A pixel circuit, a driving method therefor, and a display device. The pixel circuit comprises: a current control circuit (301), a duration control circuit (302), and a light-emitting element (303), wherein the current control circuit (301) is used for receiving a data signal (DI) and a first scan signal (gataA), and controlling the amplitude of a generated drive current according to the data signal (DI) and the first scan signal (gataA), and the duration control circuit (302) is used for receiving a mode control signal (DT), a pulse control signal (hf), a light-emitting control signal (em_b), and the drive current of the current control circuit (301), and controlling, according to the amplitude of the mode control signal (DT), the length of time for providing the light-emitting element (303) with the drive current.