Retainer Assembly for Precise Circuit Board Alignment in Supply Items
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Solution Overview
Problem
In electrophotographic image forming devices, establishing a reliable electrical connection between processing circuitry on supply items and the image forming device is challenging due to dimensional variations and lack of precise alignment, leading to potential print defects and malfunction caused by contaminants.
Innovation Solution
A retainer with positional control features that ensures precise alignment and minimizes external forces, incorporating alignment devices such as cylindrical posts and slots, and deformable features to accommodate tolerance variations and remove contaminants from the contact surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the circuit board is mounted on the supply item without precise positioning features, then the device complexity is reduced and ease of manufacture is improved, but the manufacturing precision of the electrical connection is insufficient leading to misalignment between connector contacts and circuit board contacts
Solution Approach 1:
The retainer incorporates self-aligning features including cylindrical posts that fit into corresponding slots, and deformable features that automatically adjust during assembly. The circuit board has locating features that automatically position it relative to the retainer without requiring complex external positioning mechanisms, enabling self-service alignment that achieves precise electrical connection while keeping the overall device simple
Solution Approach 2:
The retainer includes deformable features that change their physical state during assembly - transitioning from a relaxed state to a deformed state when the circuit board is installed. This parameter change allows the retainer to accommodate tolerance variations in circuit board dimensions while maintaining precise alignment, resolving the contradiction between simplicity and precision
2Reliability
If the connector contacts exert force on the circuit board to establish reliable electrical connection, then the reliability of electrical connection is improved, but the force balance between toner cartridge and imaging unit is disrupted causing print defects
Solution Approach 1:
The retainer acts as an intermediary component between the connector and the circuit board. It provides a mounting surface for the circuit board and transmits the connecting force in a controlled manner, distributing the force evenly to maintain the force balance between the toner cartridge and imaging unit while still establishing reliable electrical connection, thereby preventing print defects
Solution Approach 2:
The deformable features of the retainer are designed to absorb and cushion the connecting force before it reaches the circuit board and surrounding components. This beforehand cushioning prevents sudden force imbalances that could cause print defects, while still ensuring adequate contact force for reliable electrical connection
3Ease of operation
If the supply item is installed and removed multiple times, then the productivity and ease of operation are improved, but contaminants accumulate on the contact surfaces causing wear and malfunction
Solution Approach 1:
The retainer includes built-in cleaning features that perform preliminary cleaning action on the contact surfaces during the normal installation process. As the circuit board is inserted into the retainer, the contact surfaces are automatically cleaned of contaminants before electrical connection is established, preventing contaminant accumulation from repeated installations while maintaining ease of operation
Data Source
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AI summary
A retainer mountable on an exterior surface of an insertable supply item of an image forming device for holding a circuit board having processing circuitry with a plurality of contacts. A reference datum point in the retainer aligns the circuit board with the retainer while a pair of alignment devices align the retainer with respect to the supply item. The supply item is inserted into a frame with the image forming device have an electrical connector having a plurality of connecting pins. When the retainer and circuit board are mounted on the supply item and the supply item is inserted into the frame of the image forming device, the retainer aligns the plurality of connecting pins of the connector with corresponding ones of the plurality of contacts of the circuit board for electrical interconnection therebetween.