Triangle-Wave Pixel Driving for Low-Power High-Contrast Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices face challenges in reducing power consumption, improving contrast, and achieving high definition due to issues with backlighting and color filtering, particularly in head-mounted displays where weight and power consumption are critical.
Innovation Solution
A novel driving method for display devices using a triangle wave to control light emission in pixels, incorporating transistors and capacitors to optimize luminance and contrast, with power-saving black insertion and area sequential driving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a liquid crystal element with a single light source and color filters is used, then the display structure is simple, but the contrast is poor and black cannot be displayed without turning off the backlight
Solution Approach 1:
The patent applies field-sequential color display method where red, green, and blue light sources are sequentially activated in different time periods within each frame. This periodic switching enables high contrast black display (when all light sources are off) while maintaining simple liquid crystal structure without color filters.
2Manufacturing precision
If field-sequential method with multiple light sources is used, then higher definition and reduced pixel size are achieved, but power consumption increases due to emission and non-emission of lights
Solution Approach 1:
The patent implements selective light emission control where only the required color light sources are activated for each pixel based on the display content. When displaying black or grayscale, the light sources remain off. This partial action approach reduces power consumption compared to continuous operation while maintaining the field-sequential high definition display capability.
3Use of energy by moving object
If head-mounted display with large battery is used to compensate for high power consumption, then power supply is sufficient, but weight increases and user burden increases
Solution Approach 1:
The display device performs self-service by intelligently controlling the activation of light sources based on display content requirements. The system automatically reduces power consumption during black display, grayscale display, or when fewer colors are needed, eliminating the need for oversized batteries and reducing overall device weight.
4Measurement precision
If PWM driving with triangle wave is used to control light sources, then luminance control precision is improved, but circuit complexity increases
Solution Approach 1:
The patent employs a universal triangle wave signal that serves multiple functions: it controls the PWM driving of all light sources, provides timing synchronization for field-sequential operation, and enables luminance modulation. This multi-functional approach achieves precise luminance control without proportionally increasing circuit complexity.
Data Source
AI summary
A novel display device where a light-emitting element is turned on by a triangle wave is provided. One embodiment of the present invention is a method for driving a display device including a first pixel, a second pixel, a first wiring, a second wiring, and a third wiring. The first wiring is electrically connected to the first pixel and the second pixel. The second wiring and the third wiring are electrically connected to the first pixel and the second pixel, respectively. At a first time, the first pixel reaches the maximum luminance corresponding to first display data and the second pixel reaches the maximum luminance corresponding to second display data. The first pixel and the second pixel are initialized at a second time different from the first time by input of a reset signal to the first wiring to stop light emission.