Optical Scanning Device Thermal Management via Insulating Room
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Solution Overview
Problem
The existing optical scanning devices in image forming apparatuses face temperature gradient issues due to uneven heat distribution from the polygon motor, leading to refractive index differences in the fθ lens, which cause image distortion.
Innovation Solution
Incorporating a heat-insulating room above the fθ lens, defined by a recess and a plate, to reduce heat transfer and maintain a uniform temperature within the housing, thereby minimizing temperature gradients and refractive index variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a thermally conductive member is disposed between high-temperature and low-temperature portions to equalize temperature, then temperature uniformity is improved, but device complexity increases
Solution Approach 1:
The patent introduces a heat-insulating room as an intermediary structure that indirectly manages heat transfer. Instead of directly conducting heat between hot and cold spots, the insulating room creates a controlled thermal environment around the fθ lens, allowing temperature equalization without adding complex thermal conduction components.
Solution Approach 2:
The patent extracts the heat-insulating function from the main housing structure by creating a separate, dedicated heat-insulating room. This isolation allows the fθ lens to be protected from temperature gradients without requiring the entire housing to be thermally managed, simplifying the overall system.
2Temperature
If a metallic member is added between the main frame and housing to dissipate heat, then temperature uniformity is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts the thermal management function into a separate heat-insulating room rather than integrating it into the main housing structure. This separation simplifies manufacturing by allowing the insulating room to be added as a modular component without redesigning the entire housing assembly.
Solution Approach 2:
The patent applies thermal insulation locally around the fθ lens rather than throughout the entire housing. This localized approach reduces manufacturing complexity by focusing thermal management only where it is critical for image quality, rather than requiring uniform thermal management across all components.
3Manufacturing precision
If the housing structure is modified to include heat insulation, then image quality is improved, but device complexity increases
Solution Approach 1:
The heat-insulating room acts as an intermediary between the heat-generating polygon motor and the temperature-sensitive fθ lens. This intermediate structure protects the lens from thermal effects without requiring direct modification of the lens or motor, maintaining manufacturing precision while adding minimal complexity.
Solution Approach 2:
The patent segments the housing into distinct functional zones: a heat-generating area around the polygon motor and a temperature-controlled area around the fθ lens, separated by the heat-insulating room. This segmentation allows each zone to be optimized independently, improving image quality without uniformly increasing complexity throughout the entire device.
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 solution effectively reduces temperature gradients in the fθ lens, preventing image distortion and maintaining image quality by ensuring consistent heat dissipation and refractive index stability.
Implementation Method 1
a heat-insulating room disposed in an area above a portion of the fθ lens away from the first wall portion in a direction of extension of the fθ lens and insulating heat radiated from the internal space
Implementation Method 2
an fθ lens disposed between the polygon motor and the second wall portion to extend in a direction perpendicular to the first wall portion and configured to refract the laser light deflected by the polygon mirror
Implementation Method 3
the laser light incident on the polygon mirror driven into rotation by the motor is reflected and deflected by the mirror surfaces of the polygon mirror
Data Source
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AI summary
An exposure device includes a polygon motor, an fθ lens, and a heat-insulating room. The polygon motor is driven into rotation while producing heat, which makes it likely that the temperature of a portion of the fθ lens near a housing right wall becomes lower than that of a portion of the fθ lens near a housing left wall. The exposure device further includes a recess located above the fθ lens and extended in a right-and-left direction. The heat-insulating room is formed by disposing a plate above the portion of the fθ lens near the housing right wall to cover the recess. Thus, the plate restricts upward heat release from the portion of the fθ lens near the housing right wall.