Navigation Device Clock Circuit Power Saving Method
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Solution Overview
Problem
Conventional optical navigation devices, such as optical mice, only conserve power in sleep mode and not in normal operation mode, limiting the extension of battery life.
Innovation Solution
A navigation device with a main clock circuit and an auxiliary clock circuit, where the main clock is disabled during parts of the burst period in normal operation mode and only a part of pixel data is processed in sleep mode, using a lower frequency auxiliary clock, to reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the main clock circuit operates continuously in normal operation mode, then the navigation device can maintain accurate navigation performance, but the power consumption remains high and battery life is limited
Solution Approach 1:
The patent implements periodic action by enabling the main clock circuit only during specific burst periods for capturing image frames and disabling it during intervals when displacement calculation is performed. This periodic operation allows the system to maintain navigation accuracy when needed while reducing power consumption during processing intervals, directly resolving the contradiction between continuous operation accuracy and power savings.
2Use of energy by moving object
If the main clock circuit is disabled to save power, then power consumption is reduced, but the navigation device cannot maintain continuous operation and measurement accuracy
Solution Approach 1:
The patent applies preliminary action by capturing multiple image frames (first, second, and third images) during enabled burst periods before disabling the main clock circuit. The displacement calculations are then performed using these pre-captured frames during the disabled period, ensuring navigation accuracy is maintained through advance data collection while achieving power savings through subsequent processing during low-power intervals.
3Measurement precision
If all pixel data is processed in sleep mode, then complete navigation information is obtained, but the power saving effect is significantly reduced
Solution Approach 1:
The patent implements the extraction principle by selectively processing only essential pixel data from the captured image frames during sleep mode. Instead of processing all pixel data, the system extracts and processes only the critical portions needed for displacement calculation, thereby maintaining navigation information completeness while significantly reducing the power consumption associated with full data processing in low-power mode.
Data Source
AI summary
A navigation device includes an image sensor, a processing unit, a main clock circuit and an auxiliary clock circuit, wherein a clock frequency of the auxiliary clock circuit is much lower than that of the main clock circuit. The image sensor captures a predetermined number of image frames in a burst period. The processing unit is configured to calculate a displacement according to the image frames, to disable the main clock circuit after the predetermined number of image frames have been captured by the image sensor and to restart the main clock circuit with the auxiliary clock circuit before the end of the burst period.