Radio-Controlled Timepiece Frequency Adjustment
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Solution Overview
Problem
Radio-controlled timepieces face challenges in reliably receiving time information due to electromagnetic noise from digital display screens, which can damage the quality of demodulated time codes and result in inaccurate timekeeping due to oscillating frequency deviations.
Innovation Solution
A radio-controlled timepiece with a CPU-controlled frequency setting unit that adjusts the driving frequency of the digital display to prevent overlap with the standard radio wave frequency, using a logical slowing/quickening mechanism to correct oscillating frequency errors and ensure accurate timekeeping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the digital display screen is driven at a fixed frequency, then the display function is maintained, but electromagnetic noise overlaps with the radio wave receiving frequency due to oscillating frequency deviation
Solution Approach 1:
The patent dynamically adjusts the driving frequency of the digital display screen based on the actual oscillating frequency of the clock signal. Instead of using a fixed driving frequency, the system measures the actual oscillating frequency and calculates the driving frequency that avoids harmonic overlap with the radio wave receiving frequency, thereby adaptively resolving the electromagnetic noise issue
Solution Approach 2:
The patent changes the driving frequency parameter of the digital display screen based on the measured oscillating frequency. By calculating the relationship between the actual oscillating frequency and the radio wave receiving frequency, the system adjusts the driving frequency to ensure that harmonic frequencies do not overlap with the receiving frequency, thus eliminating electromagnetic interference
2Device complexity
If the oscillating frequency is not accurately controlled, then the circuit complexity is reduced, but the timekeeping accuracy deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where the actual oscillating frequency is measured and used to adjust the driving frequency of the digital display screen. This feedback loop ensures that even with simple oscillating circuits that may have frequency deviations, the system can dynamically compensate by adjusting the display driving frequency to avoid electromagnetic interference
Solution Approach 2:
The system uses the measured oscillating frequency information from the clock signal itself to determine the appropriate driving frequency for the display screen. The oscillating circuit's own characteristics are used to guide the frequency adjustment, eliminating the need for external complex frequency control mechanisms
3Reliability
If the driving frequency is adjusted to avoid overlap, then electromagnetic noise interference is reduced, but the display functionality may be affected
Solution Approach 1:
The patent changes the driving frequency parameter within the normal operating range of the display screen. By adjusting only the frequency parameter and maintaining other display parameters unchanged, the system ensures that the display continues to function normally while avoiding electromagnetic interference with radio wave reception
Data Source
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AI summary
Disclosed is a radio-controlled timepiece. The radio-controlled timepiece includes an oscillating unit, a display unit, a display driving unit, an error storage unit, a radio wave receiving unit, and a frequency setting unit. The display driving unit drives the display unit with a driving signal of a predetermined driving waveform frequency generated by the clock signal output by the oscillating unit. The error storage unit stores error data of an oscillating frequency. The radio wave receiving unit tunes to a receiving frequency of a radio wave including time information, and receives the radio wave. The frequency setting unit sets the driving waveform frequency based on the error data so that the receiving frequency does not overlap with a higher order harmonic wave of the driving waveform frequency during a period that the radio wave is received.