MEMS Mirror Optical Scanner APC Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In optical scanning devices using multiple laser beams for increased image formation speed, the time required for Auto Power Control (APC) increases, leading to a decrease in the effective image area due to the mechanical limitations of the MEMS mirror's reciprocating movement.
Innovation Solution
The optical scanning device performs APC on at least one laser beam after detecting a horizontal synchronization signal, allowing the device to control the light amount of the laser beams without reducing the effective image area, by executing the APC when the laser beams are not radiated on the photoconductive drum, and using a control unit to manage the light sources and MEMS mirror movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a plurality of laser beams are radiated to increase image formation speed, then productivity is improved, but the time required for APC increases and effective image area decreases
Solution Approach 1:
The patent performs APC on at least one laser beam in advance during the period when the MEMS mirror is moving in the reciprocating direction and before the laser beams are radiated on the photoconductive drum. This preliminary action ensures that APC is completed before the effective image area is used, preventing loss of effective image area while maintaining high productivity.
2Measurement precision
If APC is performed on multiple light sources, then light amount control precision is improved, but the time required for APC increases
Solution Approach 1:
The patent performs APC on at least one laser beam in advance during the reciprocating movement of the MEMS mirror, before the laser beams are radiated on the photoconductive drum. This timing strategy allows precise light amount control to be completed beforehand, avoiding time conflicts with the effective image area usage.
Solution Approach 2:
The patent performs APC periodically during the reciprocating movement cycles of the MEMS mirror, specifically during the non-radiation phase when the mirror is moving between scanning cycles. This periodic action allows multiple light sources to be controlled with precise timing, ensuring each APC operation completes within the available time window without compromising precision.
3Device complexity
If the distance of reciprocating movement of MEMS mirror is mechanically determined, then device complexity is reduced, but effective image area decreases when APC time increases
Solution Approach 1:
The patent performs APC in advance during the reciprocating movement of the MEMS mirror, before the laser beams are radiated on the photoconductive drum. This timing strategy allows APC to be completed within the fixed mechanical travel distance of the MEMS mirror, preventing any reduction in effective image area while maintaining the simplicity of the mechanical structure.
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
This approach maintains a wider effective image area by performing APC only when necessary, ensuring consistent light amounts across multiple laser beams without reducing the image formation area, thus enhancing the scanning efficiency.
Implementation Method 1
The MEMS mirror includes a reflection surface that reflects the plurality of laser beams radiated from the light source
Implementation Method 2
The sensor supplies a horizontal synchronization signal to the control unit by detecting the laser beam reflected on the reflection surface
Data Source
AI summary
An optical scanning device according to an embodiment includes a light source, a MEMS mirror, a MEMS-mirror driving unit, a control unit, and a sensor. The light source radiates a plurality of laser beams that scan a photoconductive drum. The MEMS mirror includes a reflection surface that reflects the plurality of laser beams radiated from the light source. The MEMS-mirror driving unit reciprocatingly moves the MEMS mirror. The sensor supplies a horizontal synchronization signal to the control unit by detecting the laser beam reflected on the reflection surface when the MEMS mirror reaches a predetermined position. After detecting the horizontal synchronization signal supplied from the sensor, the control unit performs the auto power control of the light amount of at least one laser beam among the plurality of laser beams.