Light-Adjusting Unit Thermal Isolation and Noise Reduction
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Solution Overview
Problem
Existing light-adjusting units in projectors suffer from thermal expansion and noise issues due to heat transfer, leading to gear seizure and unstable operation, especially under low temperature conditions.
Innovation Solution
The light-shielding plate is positioned on one surface of the supporting substrate, with rotation transmitting gears on the opposite side, preventing heat transfer and using helical gears to reduce noise, and coil springs are used to press these gears against the substrate, minimizing rattling and heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gears are provided on the same side as the light-shielding plate to transmit rotation, then the light-adjusting function is achieved, but thermal expansion causes gear seizure
Solution Approach 1:
The supporting substrate is divided into two surfaces: one surface mounts the light-shielding plate while the opposite surface mounts the gears. This spatial segmentation separates the heat-generating optical components from the temperature-sensitive mechanical components, preventing thermal transfer and subsequent gear expansion/seizure.
2Device complexity
If spur gears are used for rotation transmission, then the structure is simple, but noise occurs due to gear engagement
Solution Approach 1:
The gear type is changed from spur gear to helical gear. This parameter change modifies the engagement characteristics, allowing gradual tooth contact that reduces impact and noise during rotation transmission, while maintaining the simple structural advantage of gear-based drive mechanisms.
3Object-generated harmful factors
If lubricant is applied to reduce gear noise, then noise is reduced initially, but seizure occurs due to foreign substances adhering to grease
Solution Approach 1:
The harmful element (lubricant/grease) is completely removed from the system. Instead of using lubricated spur gears, the invention employs helical gears that achieve silent operation through their geometric design alone, eliminating the risk of lubricant degradation and foreign substance contamination.
4Reliability
If the light-shielding plate rotates to adjust light amount, then dynamic contrast is improved, but rattling occurs during rotation
Solution Approach 1:
The gear configuration is changed from spur gear to helical gear, which fundamentally alters the engagement parameters. The helical teeth engage gradually rather than abruptly, eliminating impact and rattling during rotation while maintaining precise control of the light-shielding plate position for accurate light amount adjustment.
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 configuration prevents gear seizure, reduces noise, and ensures stable long-term operation with high dynamic contrast and silencing of the light-adjusting unit.
Implementation Method 1
coil springs are used to press these gears against the substrate, minimizing rattling and heat transfer
Implementation Method 2
The gear and the rotation transmitting gears have a configuration of a helical gear, so that a noise at the time of driving may be reduced
Implementation Method 3
since the rotation transmitting gears are provided on the side opposite from the side where the light flux passes, heat generated by the light flux blocked by the light-shielding plate is hardy transferred. Accordingly, thermal expansion of the rotation transmitting gears does not occur easily
Data Source
AI summary
A light-adjusting unit includes: a light-shielding plate centered an optical axis of an incoming light flux and configured to block the light flux in response to the amount of rotation; a rotation transmitting gear configured to hold and rotate the light-shielding plate; a supporting shaft configured to rotatably support the rotation transmitting gear; and a supporting substrate on which the supporting shaft is provided, and the light-shielding plate is provided on one surface side of the supporting plate, and the rotation transmitting gear is provided on the other surface side of the supporting substrate opposite to the one surface side.