Display Device Frame Memory Timing Control for Tearing Prevention
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Solution Overview
Problem
Display devices experience a 'tearing effect' due to mismatched writing and reading speeds of image data from frame memory, causing pixels to emit light based on previous or current frame data, leading to a distorted image.
Innovation Solution
A display device and driving method that utilize a single frame memory, where the controller ensures scan signals are transmitted to all pixel rows during the address period of the earliest sub-field within a frame, with image data storage time being less than or equal to half of the frame duration, preventing the tearing effect by synchronizing data transmission with image data storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the frame memory stores image data at a different speed than it transmits the data, then the data transmission efficiency is improved, but the tearing effect occurs causing image distortion
Solution Approach 1:
The frame memory completes storing the entire current frame's image data before the scan signals begin transmitting any data from that frame to the display panel. This preliminary completion of data storage ensures that all pixels receive consistent data from the same frame, preventing the tearing effect while allowing efficient data transmission during the display period
2Reliability
If additional frame memory is used to prevent tearing effect, then image integrity is improved, but the device complexity and cost increase
Solution Approach 1:
The single frame memory serves dual functions: it acts as both the storage buffer for incoming image data and the source for transmitting display data. By carefully timing the storage completion before transmission begins, the system achieves tearing prevention without requiring separate dual-buffer memory structures, thus maintaining simplicity while ensuring image integrity
Data Source
AI summary
A display device includes a driver connected to a display panel and transmitting scan signals or data signals to the display panel, a frame memory connected to the driver, storing image data and transmitting at least some of the image data to the driver, and a controller connected to the driver and the frame memory, generating a control signal and transmitting the control signal to the driver or the frame memory, wherein each of the sub-fields includes an address period in which the scan signals are transmitted to the respective pixel rows, the controller transmits the control signal to the driver to transmit the scan signals to the pixel rows during a current frame such that the scan signals corresponding to the current frame are transmitted after, among the image data corresponding to the current frame, the image data corresponding to the pixel rows are stored in the frame memory.