Scan Driver Clock Duty Control for Low-Flicker Display Driving
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Solution Overview
Problem
Display devices experience flicker phenomena and high power consumption when driven at low frequencies, particularly in still image display modes.
Innovation Solution
The display device employs a scan driver with increased clock signal lines and adjusted clock duty cycles to reduce driving frequency, incorporating data blank periods between sub-frames, and selectively switches between normal and low frequencies based on image content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the display device is driven at a low frequency to reduce power consumption, then power consumption is reduced, but a flicker phenomenon occurs due to leakage characteristic
Solution Approach 1:
The patent applies periodic action by implementing interlaced scanning that alternately drives odd-numbered and even-numbered scan lines in separate sub-frames. This periodic activation pattern allows the display to operate at lower frequencies while maintaining stable image quality and reducing flicker through the systematic alternation of line groups.
Solution Approach 2:
The patent segments the scan lines into multiple groups (odd-numbered lines in one sub-frame, even-numbered lines in another sub-frame). This segmentation allows independent control of different line groups, enabling the display to reduce power consumption by activating only necessary line groups while preventing flicker through coordinated scanning of segmented line sets.
2Reliability
If progressive scanning method is used to drive all scan lines in every frame, then image quality is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic action through interlaced scanning, where odd-numbered scan lines are driven in one sub-frame and even-numbered scan lines are driven in another sub-frame. This periodic alternation maintains complete image coverage similar to progressive scanning while reducing power consumption by activating only half the scan lines in each sub-frame period.
Solution Approach 2:
The patent applies dynamics by adaptively switching between progressive scanning and interlaced scanning modes based on display content requirements. The system dynamically adjusts the scanning method to balance image quality and power consumption, using interlaced scanning for static content and progressive scanning for dynamic content.
3Loss of energy
If interlaced scanning method is used to alternate driving odd and even scan lines, then power consumption is reduced, but image quality deteriorates for video display
Solution Approach 1:
The patent employs dynamics by implementing adaptive scanning mode selection that switches between interlaced scanning for power savings and progressive scanning for superior image quality. The system dynamically determines the appropriate scanning mode based on content characteristics, ensuring optimal balance between power consumption and image quality for different display scenarios.
Solution Approach 2:
The patent applies parameter changes by modifying the scanning frequency and line activation patterns based on display content. The system changes operational parameters such as frame rate, sub-frame structure, and line group activation to optimize both power consumption and image quality, adjusting these parameters dynamically according to content requirements.
Data Source
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AI summary
A display device (10) according to an embodiment of the disclosure includes a timing controller (11), a scan driver (13) including a plurality of stages (ST1, ..., ST8) connected to a plurality of clock signal lines (CLKL1, ..., CLKL8) and generating a plurality of scan signals in response to the scan start signal (FLM), a data driver (12) configured to generate a plurality of data signals based on the image data, and a pixel portion (14) including a plurality of pixels. One stage (ST1, ..., ST8) in the scan driver (13) transmits a carry signal to a 2n-th next stage. The timing controller (11) selects one among a normal frequency and low frequencies lower than the normal frequency as a driving frequency based on the input image data, and adjusts a clock duty of the plurality of clock signals (CLK1, ..., CLK8) so that a time required to output all of the plurality of scan signals during one frame is constant irrespective of the driving frequency.