Sheet Path Feeler Positioning for Accurate Jam Detection
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Solution Overview
Problem
Existing sheet conveying devices in image forming apparatuses suffer from inaccurate detection of sheet presence and jam occurrence due to cover deformation, which affects the positioning of the feeler with respect to the photosensor, leading to erroneous detection.
Innovation Solution
A sheet conveying device with a positioner in the body to contact the feeler and maintain its position relative to the photosensor, ensuring accurate detection even when the cover is deformed, using a detector comprising a photosensor and a movable feeler with a detected portion and contacted portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the cover is made openable and closable to enable sheet removal, then the ease of operation is improved, but the positioning accuracy of the feeler with respect to the photosensor deteriorates due to cover deformation
Solution Approach 1:
A feeler is introduced as an intermediary component between the cover and the photosensor. The feeler transfers the positional relationship from the deformable cover to the fixed photosensor, allowing the photosensor to accurately detect sheet presence even when the cover deforms during opening/closing operations
2Ease of operation
If the cover is made deformable to enable opening and closing, then the ease of operation is improved, but the reliability of sheet detection deteriorates due to positioning errors
Solution Approach 1:
The feeler acts as a mediator that decouples the detection reliability from cover deformation. By having the feeler contact the sheet and transmit this information to the photosensor, the system maintains reliable detection regardless of cover shape changes during operation
3Adaptability or versatility
If the feeler is made movable relative to the cover to enable detection, then the adaptability to cover deformation is improved, but the positioning accuracy of the feeler with respect to the photosensor deteriorates
Solution Approach 1:
The feeler serves as an intermediary that adapts to cover deformation through its movability while maintaining accurate positioning relative to the photosensor. The feeler's ability to move with the cover ensures continuous contact with the sheet, while its geometric relationship with the photosensor remains fixed for accurate detection
Solution Approach 2:
The feeler is designed with movable capability to dynamically adapt to cover deformation during opening and closing. This dynamic adjustment allows the feeler to maintain proper positioning and functionality despite changes in cover shape and position
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
Enhances the accuracy of sheet detection and jam determination, preventing erroneous readings and reducing the likelihood of sheet jams, particularly in devices with low-strength components like the fixing belt, thereby maintaining device functionality and safety.
Implementation Method 1
The detector includes a photosensor in the body and a feeler in the cover. The feeler is movable relative to the second guide. The feeler includes a detected portion and a contacted portion. The detected portion is movable in conjunction with the sheet passing through the sheet conveyance path. The photosensor has a detection region in which the detected portion entering the detection region is detected by the photosensor.
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
A sheet conveying device (49) includes a body (1), a first guide (54) in the body (1), a cover (50), a second guide (55) in the cover (50), a detector (90), and a positioner (59). The first and second guides (54 and 55) form a conveyance path at a closed state of the cover (50). The detector (90) detects a sheet in the conveyance path and includes a photosensor (91) in the body (1) and a feeler (92) in the cover (50). The feeler (92) includes a detected portion (92c) movable in conjunction with the sheet passing through the conveyance path and a contacted portion (92d). The photosensor (91) has a detection region (91a) in which the detected portion (92c) entering the detection region (91a) is detected. The positioner (59) in the body (1) contacts the contacted portion (92d) to position the detected portion (92c) in the detection region (91a).