Light Scanning Mirror Control for Temperature and Axis Shift Errors
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Solution Overview
Problem
Existing light scanning apparatuses face challenges in achieving high-precision operation when the mirror is swung in a linear mode with each of the first axis and the second axis as the central axis, particularly in applications like 3D printing and optical interference tomography, where accuracy to ±0.1° or less is required.
Innovation Solution
A light scanning system that includes a mirror device with first and second movable parts, a magnet generating a magnetic field, a temperature sensor, and an arithmetic part. The arithmetic part generates current signals for the drive coils based on target deflection angles, frequencies, and correction data to ensure precise mirror movement, accounting for changes in frequency, temperature, and axis shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the mirror is swung in a linear mode with each axis as the central axis, then the deflection angle is proportional to the current value, but the error with respect to the target deflection angle increases beyond ±0.1°
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing correction values for deflection angles at multiple current values and temperatures before operation. The arithmetic part retrieves these pre-computed correction values during operation to compensate for temperature-induced deviations, thereby maintaining precision without real-time complex calculations.
Solution Approach 2:
The patent implements feedback through temperature detection using a temperature sensor that continuously monitors the mirror device temperature. The detected temperature is fed back to the arithmetic part, which then selects appropriate correction values from stored data to adjust the drive current, ensuring the actual deflection angle matches the target deflection angle despite temperature variations.
2Manufacturing precision
If correction data for frequency changes, axis shifts, and temperature changes is integrated, then the deflection angle precision is improved to ±0.05° or less, but the device complexity increases
Solution Approach 1:
The patent pre-computes and stores correction values for multiple parameters (frequency changes, axis shifts, and temperature changes) in a lookup table format before operation. This allows the arithmetic part to quickly retrieve and apply appropriate corrections without performing complex real-time calculations, thereby maintaining high precision while avoiding excessive computational complexity.
Solution Approach 2:
The patent addresses parameter changes by storing correction data for various operating conditions (different temperatures, frequencies, and axis positions) and selecting the appropriate correction values based on detected parameters. This allows the system to adapt to changing operating conditions while maintaining precision through parameter-based correction rather than complex dynamic control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system achieves high-precision operation by accurately controlling the mirror's deflection angle and frequency, reducing errors to ±0.05° or less, and maintaining precision across varying temperatures and axis orientations.
Implementation Method 1
a magnet configured to generate a magnetic field to act on a first drive coil provided in the first movable part and a second drive coil provided in the second movable part
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3
AI summary
A light scanning system includes a mirror device, a magnet, a temperature sensor, and an arithmetic part. The arithmetic part generates a first current signal and a second current signal based on a first target deflection angle and a first target frequency, a second target deflection angle and a second target frequency, an operating temperature, first data for correcting a change in a deflection angle of a mirror with respect to a change in a frequency of a current signal input to each of a first drive coil and a second drive coil, second data for correcting at least one of a shift of the mirror swinging with a first axis as a central axis from a Y-axis and a shift of the mirror swinging with a second axis as a central axis from an X-axis, and third data for correcting a change in a deflection angle of the mirror with respect to a change in the operating temperature.