Light Scanning Unit Housing Thermal Deformation Prevention
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Solution Overview
Problem
In electrophotographic image forming apparatuses, the thermal deformation of plastic resin housings used in light scanning units leads to deviations in image forming positions, particularly in color image forming apparatuses with closely spaced light sources, increasing material costs and complexity due to the need for elastic members and additional parts.
Innovation Solution
A light scanning unit with a housing made of plastic resin and a deformation prevention member made of metal or plastic resin with a lower thermal expansion coefficient, connecting opposite sides of the housing across the base surface, which helps to prevent thermal deformation and includes a strength reinforcement structure such as a bent portion, embossment, or rib, and a heat dissipation hole.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If plastic resin housing is used in light scanning unit, then material cost is reduced and ease of manufacture is improved, but thermal deformation occurs causing image forming position deviation
Solution Approach 1:
The patent uses a composite structure combining plastic resin housing with metal reinforcement members (brackets or ribs). The plastic resin provides ease of manufacture and cost benefits, while the metal components with low thermal expansion coefficients compensate for thermal deformation, maintaining image forming position precision.
2Stability of the object's composition
If elastic members are added to compensate for thermal deformation, then image forming position stability is improved, but device complexity and material cost increase
Solution Approach 1:
The patent extracts and eliminates the need for elastic members by using a rigid reinforcement structure (metal bracket or rib) that passively resists thermal deformation through its material properties. This removes the complexity and cost associated with elastic members while maintaining position stability.
3Reliability
If multiple separate holders are used for closely spaced light sources, then each light source can be individually secured, but device complexity and material cost increase
Solution Approach 1:
The patent merges multiple separate holder functions into a single integrated reinforcement structure. The metal bracket or rib simultaneously supports multiple closely spaced light sources, reducing the number of parts and simplifying assembly while maintaining reliable mounting for each light source.
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 solution effectively reduces thermal deformation, minimizing color registration errors and maintaining image quality by stabilizing the image forming positions, even at varying temperatures, thus reducing material costs and simplifying the assembly process.
Implementation Method 1
the housing formed of a plastic resin material has a problem in that parts of the housing may be thermally deformed according to a change in peripheral and internal temperatures
Data Source
AI summary
A light scanning unit includes a light source unit emitting a light beam according to an image signal, a light deflector scanning the light beam that is deflectively emitted by the light source unit, a housing having a side portion where the light source unit is provided and a base surface on which the light deflector is provided, and a deformation prevention member connecting opposite sides of the housing across an upper side of the base surface. The light scanning unit is employed by an image forming apparatus.