Projector Lens Drive Backlash Reduction via Directional Control
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Solution Overview
Problem
Conventional projectors with motorized zoom, focus, and lens shift functions face limitations in responsiveness and accuracy due to backlash in the drive mechanism, failing to meet user demands for fine adjustments and quick movements.
Innovation Solution
A projector system that determines whether the drive instruction direction for the lens section is the same or different from the last direction, using distinct control values to adjust the driving mechanism accordingly, thereby reducing backlash and improving responsiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed control value is used for normal operation, then the operation is simple, but the responsiveness and accuracy of lens movement are insufficient
Solution Approach 1:
The patent applies dynamics by making the control value variable rather than fixed. The control value changes based on the drive direction: a first control value is used when driving in the same direction as the last drive, and a second control value (larger than the first) is used when driving in the opposite direction. This dynamic adjustment allows the system to respond quickly to direction changes while maintaining simple operation for the user.
2Device complexity
If a fixed control value is used for normal operation, then the control mechanism is simple, but the backlash in the drive mechanism cannot be reduced
Solution Approach 1:
The patent applies parameter changes by modifying the control value parameter based on drive direction. When the drive direction is opposite to the last drive direction, a larger control value (second control value) is used to overcome backlash in the gear mechanism. When the drive direction is the same, a smaller control value (first control value) is used. This parameter adjustment reduces backlash effects without complicating the overall control mechanism.
3Stability of the object's composition
If the motor drives the lens section with fixed control value, then the system is stable, but the accuracy of fine adjustments is insufficient
Solution Approach 1:
The patent applies dynamics by adjusting the control value based on drive direction to achieve both stability and precision. The system maintains stability through consistent control logic while achieving higher adjustment accuracy by using appropriate control values for different drive scenarios, allowing users to make precise fine adjustments when needed.
Data Source
AI summary
A projector includes a lens driving section that drives a lens section having a projection lens, an accepting section that accepts first control value indication information indicating a first control value including a drive instruction value of the lens section, a determining section that determines whether a drive instruction direction for the lens section is a first drive direction that is same as the last drive direction or a second drive direction that is different from the last drive direction, and a control section that drives the lens section by using a second control value whose drive instruction value is greater than the drive instruction value of the first control value in case that the drive instruction direction is the second drive direction.