Exposure Head Adhesive Layout for Thermal Position Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The adhesive used to attach the substrate with light emitting elements to the casing in an exposure head expands due to heat generated by LED emission, causing a variation in the relative position of the substrate, which affects the optical performance by varying the amount of light irradiated on the photosensitive drum, leading to potential image defects.
Innovation Solution
The exposure head employs a combination of UV adhesive and thermosetting adhesive, with the thermosetting adhesive having a smaller thermal expansion coefficient than the sealant, to securely attach the substrate to the casing, minimizing movement and twist caused by thermal expansion, ensuring consistent light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive is used to attach the substrate to the casing, then the substrate can be securely fixed, but the adhesive expands due to heat generated by LED emission, causing variation in the relative position of the substrate
Solution Approach 1:
The patent applies parameter changes by selecting adhesive materials with specific thermal expansion coefficients that match or are compatible with the substrate and casing materials. This ensures that while the adhesive provides strong attachment, its thermal expansion characteristics remain stable under LED-generated heat, preventing position variation of the substrate relative to the casing.
Solution Approach 2:
The patent employs composite material strategy by using multi-layer adhesive structures or combining different types of adhesives (e.g., UV-curing adhesive and heat-curing adhesive) to achieve both strong attachment and minimal thermal expansion. The composite adhesive system compensates for the thermal expansion issues that single-material adhesives would exhibit under heat.
2Device complexity
If the substrate position varies due to adhesive thermal expansion, then the structure remains simple, but the optical performance deteriorates due to varying light irradiation on the photosensitive drum
Solution Approach 1:
The patent maintains simple structure while ensuring optical performance by carefully selecting adhesive materials with appropriate thermal and optical parameters. The adhesive is chosen to have low thermal expansion and appropriate curing characteristics that prevent substrate displacement, thereby maintaining consistent light irradiation on the photosensitive drum without adding complex positioning mechanisms.
Solution Approach 2:
The adhesive acts as an intermediary material between the substrate and casing, mediating the thermal and mechanical interactions. By selecting adhesives with specific properties (low thermal expansion, appropriate bond strength), the system maintains optical performance while keeping the overall structure simple, avoiding the need for additional thermal compensation mechanisms.
3Stability of the object's composition
If thermosetting adhesive with smaller thermal expansion coefficient is used, then position stability is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The patent applies preliminary action by pre-selecting and pre-positioning the substrate using fixtures or jigs before adhesive application. This ensures that the substrate is correctly positioned before the adhesive cures, compensating for the more complex manufacturing process inherent in using thermosetting adhesives with specific curing requirements.
Solution Approach 2:
The patent manages manufacturing complexity by optimizing the curing parameters (temperature, time, humidity) of the thermosetting adhesive. By controlling these parameters precisely, the adhesive achieves optimal bond strength and minimal thermal expansion without requiring excessively complex manufacturing processes or equipment.
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 maintains consistent light irradiation on the photosensitive drum, preventing image defects by stabilizing the substrate's position relative to the casing, thereby enhancing the optical performance of the exposure head.
Implementation Method 1
The adhesive used to attach the substrate with light emitting elements to the casing in an exposure head expands due to heat generated by LED emission
Implementation Method 2
The exposure head employs a combination of UV adhesive and thermosetting adhesive, with the thermosetting adhesive having a smaller thermal expansion coefficient than the sealant, to securely attach the substrate to the casing
Implementation Method 3
The lens array includes a plurality of lenses configured to focus light emitted from the light emitting elements of the first light emitting chip and the second light emitting chip
Data Source
AI summary
An exposure head includes a substrate assembly including a first light emitting chip, a second light emitting chip, and a substrate on which the first light emitting chip and the second light emitting chip are mounted, a lens array, a retaining member configured to retain the substrate assembly and the lens array, and a first adhesion portion. In a state where an area on the substrate where the end portion of the second light emitting chip in the main scanning direction and the end portion of the first light emitting chip in the main scanning direction overlap when viewed in the sub-scanning direction is referred to as a first area, the first adhesion portion is configured to adhere both end portions of the substrate assembly in the sub-scanning direction to the retaining member in the first area.