EPD Cursor Positioning via High-Frequency Coordinate Sampling
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Solution Overview
Problem
Information processing devices equipped with electro-phoretic displays (EPDs) face challenges in displaying a cursor for input operations due to the long refresh time of EPDs, which can lead to delayed cursor positioning and visibility issues, making operations difficult.
Innovation Solution
An information processing system that includes a host system sampling coordinates from an input device and a controller updating a background image with an update cycle longer than the sampling cycle, allowing the cursor to be placed accurately at the indicated coordinates on the display medium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the refresh rate of EPD is used (about 8 Hz), then power consumption is reduced, but the cursor positioning delay increases and smooth cursor behavior is compromised
Solution Approach 1:
The system performs preliminary actions by updating the background image in advance at a higher frequency (60 Hz or higher) than the EPD refresh rate (8 Hz). This allows the cursor position to be pre-calculated and prepared before the actual display update, compensating for the long refresh time and reducing visible positioning delay.
Solution Approach 2:
The patent introduces an intermediary mechanism where the background image is updated at a higher frequency than the display refresh rate. This intermediary update layer acts as a buffer, allowing the cursor position to be continuously tracked and prepared while the EPD refreshes at its slower native rate, thus mediating between the fast input sampling and slow display refresh.
2Measurement precision
If the background image is updated at a high frequency to reduce cursor delay, then cursor positioning accuracy improves, but the complexity of coordinate sampling and image updating increases
Solution Approach 1:
The system segments the update process into two independent parts: (1) continuous coordinate sampling at high frequency from the input device, and (2) periodic background image updating at the EPD refresh rate. This segmentation allows each part to operate at its optimal frequency without interfering with the other, reducing overall system complexity.
Solution Approach 2:
The patent applies dynamics by making the background image update frequency adaptable. The system dynamically adjusts the update timing based on the EPD's refresh characteristics, using high-frequency sampling for cursor position tracking but synchronizing the actual image update with the display's natural refresh cycle to avoid unnecessary complexity.
3Ease of operation
If multiple cursors are displayed at different positions due to discrete updating, then the cursor movement is visible, but the user cannot recognize the target cursor and operation is disturbed
Solution Approach 1:
The system performs preliminary cursor position calculation based on high-frequency coordinate sampling before the EPD refresh cycle completes. This ensures that the cursor is positioned at the correct location in advance, allowing the user to recognize the target cursor without confusion from multiple discrete cursor positions.
Solution Approach 2:
The patent implements feedback by continuously monitoring the cursor position through high-frequency coordinate sampling and using this information to guide the background image updates. This feedback loop ensures that the cursor remains visually consistent and predictable, improving user recognition and operation.
Data Source
AI summary
An information processing system includes a host system that samples coordinates indicated by using an input device to acquire a background image, and a controller that displays an output image based on the background image on a display medium. The host system notifies the controller of the coordinates. The controller updates the background image with an update cycle longer than a sampling cycle of the coordinates, and outputs the output image with a cursor placed at the coordinates on the background image to the display medium.