OLED Display Shutdown Sequence for Residual Image Prevention
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Solution Overview
Problem
OLED display screens experience residual images due to sudden power cutoffs, leading to permanent burn-in and reduced product quality and user experience.
Innovation Solution
A displaying device with a time-sequence controlling circuit, power-supply circuit, and system controlling circuit that performs a shutting-down compensation by displaying a black frame before power-off, ensuring the display panel is powered off before the controlling circuit, using different power-supply voltages and controlled shutdown sequences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the power supply is suddenly cut off after high brightness operation, then power consumption is reduced, but residual images appear and permanent burn-in occurs
Solution Approach 1:
The patent applies preliminary action by displaying a black frame before power-off to prepare the OLED display for shutdown. The time-sequence controlling circuit controls the display panel to show a black frame during a shutdown compensation period, which compensates for the residual charge in the OLED pixels and prevents residual images and burn-in before the actual power cutoff occurs.
Solution Approach 2:
The patent applies preliminary anti-action by using a black frame display to counteract the harmful residual charge accumulation in OLED pixels before power shutdown. The black frame (with low or zero brightness) is displayed during the shutdown compensation period to offset the residual charge from previous high-brightness content, preventing the formation of residual images and permanent burn-in.
2Loss of time
If the display panel is powered off immediately, then shutdown time is reduced, but residual images cannot be compensated
Solution Approach 1:
The patent performs the residual charge compensation action in advance by displaying a black frame during the shutdown compensation period before the actual power cutoff. The time-sequence controlling circuit manages the timing to ensure the black frame is displayed for sufficient duration to compensate residual charges, while still completing the entire shutdown process quickly.
Solution Approach 2:
The patent applies dynamics by implementing a time-shared shutdown mechanism where different power supply voltages are cut off at different times. The time-sequence controlling circuit controls the display panel power supply to be shut down before the controlling circuit power supply, creating a dynamic timing sequence that enables shutdown compensation while maintaining overall fast shutdown performance.
3Reliability
If a time-shared shutdown sequence is implemented, then residual image compensation is improved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the power supply system into multiple independent voltage rails (first power supply voltage for display panel, second power supply voltage for controlling circuit). The time-sequence controlling circuit receives the same power supply as the display panel and independently controls the timing of power cutoff for different components, enabling precise time-shared shutdown without requiring complex additional control hardware.
Solution Approach 2:
The time-sequence controlling circuit serves multiple functions: it acts as both the controlling circuit for the display panel and the power management unit for time-shared shutdown. By using the same power supply connection for both the display panel and the time-sequence controlling circuit, the patent eliminates the need for separate power management hardware, reducing overall device complexity while achieving sophisticated timing control.
Data Source
AI summary
The present application provides a displaying device and a controlling method thereof, which relates to the technical field of displaying. The displaying device can solve the problem of residual images generated in power-off and greatly improve the product quality and the user experience. The displaying device includes: a time-sequence controlling circuit, a power-supply circuit, a system controlling circuit and a display panel; the power-supply circuit is electrically connected to the time-sequence controlling circuit and the system controlling circuit, and is configured for: providing a first power-supply voltage and a second power-supply voltage to the time-sequence controlling circuit, wherein a magnitude of the first power-supply voltage and that of the second power-supply voltage are different; in a normal shutdown mode, under control of the system controlling circuit, firstly shutting down an output of the first power-supply voltage, after a first time period, shutting down an output of the second power-supply voltage.