Display Driver Dynamic Refresh Rate Control for OLED Power Reduction
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Solution Overview
Problem
Existing display devices with electroluminescence (EL) elements, such as OLEDs, face challenges in achieving both high-speed display updating and low-refresh driving while minimizing power consumption and preventing burn-in phenomena.
Innovation Solution
A display device with self-luminous elements, including organic EL elements, employs a display driver and a display-data generator that controls light emission and updates the screen by reading stored display data after a predetermined time period, even during no data updates, to reduce refresh frequency and conserve power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the refresh rate of the display device is reduced to lower power consumption, then energy consumption is reduced, but the speed of display updating deteriorates
Solution Approach 1:
The display driver dynamically adjusts the refresh rate based on whether image data has been updated. When image data is updated, the driver performs display driving at a first refresh rate to ensure high-speed updating. When no update occurs, it switches to a second refresh rate lower than the first, thereby reducing power consumption. This dynamic adaptation resolves the contradiction between power consumption and display updating speed.
2Loss of energy
If the refresh rate is lowered to conserve power, then energy efficiency improves, but the responsiveness to new image data deteriorates
Solution Approach 1:
The display driver incorporates a feedback mechanism that monitors whether image data has been updated. Based on this feedback, it automatically adjusts the refresh rate: maintaining a higher rate when updates occur to ensure responsiveness, and lowering it when no updates occur to improve energy efficiency. This feedback-controlled adaptation eliminates the trade-off between energy efficiency and responsiveness.
3Reliability
If continuous display driving is performed to maintain image quality, then display performance is maintained, but power consumption increases
Solution Approach 1:
The display driver implements periodic action by alternating between different refresh rates based on update requirements. When image data is updated, it performs display driving at a first refresh rate to maintain image quality. When no update occurs, it switches to a second, lower refresh rate to reduce power consumption. This periodic adaptation maintains display performance when needed while conserving energy during stable states.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables high-speed display updating and low-refresh driving, reducing power consumption and minimizing the risk of burn-in, thereby enhancing the performance and longevity of EL display devices.
Implementation Method 1
a display unit having a screen with self-luminous elements arranged
Data Source
AI summary
A display device includes: a display unit; a display driver configured to drive the display unit; and a display-data generator configured to transfer a screenful of update display data to the display driver. The display driver includes a light-emission controller configured to control self-luminous elements to emit light, and a memory storing a screenful of the update display data. After a lapse of a predetermined time period from a driving stop time, the display driver reads the update display data stored in the memory and then uses the update display data to drive a screen, the driving stop time being a time when the display unit is stopped from driving based on the update display data. The display driver causes the self-luminous elements of the display unit to emit light, even during a display update or no display update performed on the display driver by the display-data generator.