Compact Paper Size Encoding via Radial Control Member
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Solution Overview
Problem
Existing feeding devices for image forming apparatuses face challenges in downsizing and cost reduction due to the need for large installation spaces and increased costs associated with complex mechanisms for encoding paper size information.
Innovation Solution
A feeding device with a media storage unit, a detector, and a control member that uses a pattern of recessed and projecting portions on its outer surface to encode paper size, allowing for compact design and reduced component count, enabling accurate paper size detection without a dedicated sensor for presence detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If switches are lined up in a row on the main body to detect paper size, then the detection function is achieved, but the diameter of the indicator plate becomes large and installation space is restricted
Solution Approach 1:
The patent transitions from a linear arrangement of switches in one dimension to a two-dimensional matrix array. Multiple rows and columns of switches are arranged on the detector, allowing the indicator plate to encode paper size information through the position of projected portions at the intersections of rows and columns. This dimensional change enables compact encoding without requiring a large diameter indicator plate.
2Loss of information
If a disc shaped indicator plate with pressing components is used to encode paper size, then the paper size information can be transmitted to the controller, but the diameter of the indicator plate becomes large and design flexibility is lowered
Solution Approach 1:
The patent employs a matrix array of switches arranged in multiple rows and columns, creating a two-dimensional detection space. The indicator plate uses projected portions positioned at specific row and column intersections to encode paper size information. This approach reduces the indicator plate diameter while maintaining the ability to transmit multiple paper size codes, thereby improving design flexibility.
3Measurement precision
If multiple rows of sensors are used to detect paper size with a disc shaped indicator plate, then the detection accuracy is improved, but the cost increases due to non-generic sensors
Solution Approach 1:
The patent uses a matrix array of standard, generic switches that can be mass-produced and are widely available. Each switch in the matrix serves multiple functions: detecting different paper sizes depending on which row and column intersection is activated. This universal approach allows the use of common electronic components rather than specialized sensors, reducing manufacturing costs while maintaining detection accuracy.
4Loss of information
If a columnar dial with cams is used to encode paper size, then the paper size information can be detected during attaching operation, but the size of the dial in the axial direction becomes large
Solution Approach 1:
The patent replaces the axial encoding mechanism (columnar dial extending in the axial direction) with a radial encoding mechanism using a flat indicator plate with projected portions. The paper size information is encoded in the radial position of projected portions relative to the center of the indicator plate, rather than extending axially. This dimensional change significantly reduces the axial dimension of the encoding mechanism while maintaining the ability to detect paper size during the attaching operation.
5Measurement precision
If peaks are projected radially on a size indicator plate and rotated to contact switches, then the paper size can be detected, but the installation space is restricted due to the rotational locus requirement
Solution Approach 1:
The patent uses a matrix array of switches arranged in multiple rows and columns on a flat detector surface. The indicator plate has projected portions positioned at specific radial distances from the center, corresponding to different paper sizes. When the indicator plate rotates, the projected portions contact switches at their radial positions without requiring additional axial space for rotational movement. This eliminates the need for extra installation space for the rotational locus while maintaining accurate paper size detection.
Data Source
AI summary
A feeding device includes a paper feed tray, a detector on an image forming apparatus main body, a control member rotatably supported by the paper feed tray, and spacers. The detector includes movable pieces and contact points corresponding to the movable piece, and switches each contact point by the position of the corresponding movable piece. The control member includes a control surface formed on its outer circumferential surface with projecting and recessed portions. The projecting and recessed portions are disposed in a pattern corresponding to rotation angles in an area of the control surface facing the movable pieces. Controlling the positions of the movable pieces according to the pattern encodes paper size. Each movable piece is lined in the circumferential direction facing the control surface. The outer circumferential surface of the projecting portions is formed in a cylindrical surface shape centering around the rotational axis of the control member.