Optical Scanning Device Mirror Stoppage Detection

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Solution Overview

Problem

Conventional optical scanning devices fail to accurately detect the stoppage of a scanning mirror due to contact with foreign objects or other malfunctions, leading to continuous drive signal supply and potential damage or safety hazards.

Innovation Solution

An optical scanning device comprising a light source component, a scanning component, an electrostatic driver, a controller, and a current sensor that senses current changes in the driver's capacity, allowing for accurate detection of mirror stoppage and malfunction by analyzing current waveforms and adjusting light emission accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the drive signal is adjusted to keep electrostatic capacity constant, then the electrostatic actuator operates stably, but malfunction detection capability deteriorates

Engineering Contradiction:

Improveelectrostatic capacity stabilityVSAvoidmalfunction detection capability

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent introduces an amplitude sensor as an intermediary component that indirectly detects the scanning mirror's operational state. Instead of directly monitoring the mirror's position or movement, the sensor measures the amplitude of the mirror's vibration, which serves as a mediator to infer whether the mirror is properly scanning or has stopped due to malfunction.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements a feedback mechanism where the amplitude sensor continuously monitors the scanning mirror's vibration amplitude and feeds this information back to a control unit. The control unit compares the measured amplitude against predetermined thresholds and adjusts the drive signal accordingly, creating a closed-loop control system that maintains stable operation while enabling malfunction detection.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If the scanning mirror is continuously monitored during binary movement, then minute damped vibration can be detected, but malfunction detection during continuous movement deteriorates

Engineering Contradiction:

Improvedetection precision during binary movementVSAvoidmalfunction detection during continuous movement

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent applies dynamic monitoring by continuously measuring the vibration amplitude of the scanning mirror during its operational cycles. Rather than using static thresholds, the system adapts to the dynamic characteristics of the mirror's movement, detecting anomalies in real-time regardless of whether the mirror is in binary movement or continuous scanning mode.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent utilizes the periodic nature of the scanning mirror's vibration by measuring amplitude at specific intervals during its operational cycle. The control unit analyzes these periodic measurements to detect deviations from normal operation, enabling malfunction detection during continuous movement by comparing successive periodic measurements against expected patterns.

Inventive Principle:

Principle #19Periodic action

3Device complexity

If no malfunction detection mechanism is implemented, then the device structure remains simple, but safety and damage prevention capability deteriorates

Engineering Contradiction:

Improvedetection mechanism complexityVSAvoidsafety hazard from continuous drive signal

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces complex mechanical monitoring systems with an electrical sensing approach. Instead of using mechanical sensors or switches to detect mirror stoppage, the system uses an amplitude sensor that measures electrical signals from the mirror's vibration, substituting a simple electrical measurement for what would otherwise require complex mechanical detection infrastructure.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 device effectively prevents accidents by accurately detecting mirror stoppage and malfunctions, reducing the risk of damage and ensuring safe operation by controlling light emission based on sensed current changes.

Implementation Method 1

The driver is an electrostatic driver that drives the scanning component

Methodology Applied

Scientific EffectElectrostatic force: Electrostatics

Implementation Method 2

The current sensor senses current generated by a capacity change of the driver

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS10750143B2Optical scanning device

Publication Date: 2020.08.18 FEC IP LLC

AI summary

An optical scanning device includes a light source component, a scanning component, an electrostatic driver, a controller, and a current sensor. The light source component emits light. The scanning component scans the light. The driver drives the scanning component. The controller controls emission of the light from the light source component. The current sensor senses current generated by a capacity change of the driver. The controller further controls the emission of the light from the light source component based on the sensed current sensed by the current sensor.