Sheet Conveyance Skew Correction for Transparent Media Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image forming apparatuses struggle to accurately detect and correct the skewing of transparent sheets, such as OHP films, during conveyance, leading to potential collisions with reference guides and improper alignment.
Innovation Solution
A sheet conveyance apparatus with a rotary member pair, an obliquely conveying portion, and a detection portion that adjusts the position of the sheet using a control unit to execute various modes of movement based on detection results or independently of them, ensuring accurate alignment and skew correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a detection apparatus is used to detect the position of the sheet edge, then the width-direction position of the sheet can be adjusted, but transparent sheets cannot be detected by the detection apparatus
Solution Approach 1:
A reflective member is introduced as an intermediary between the detection apparatus and the transparent sheet. The reflective member reflects light from the detection apparatus to illuminate the transparent sheet, enabling the detection apparatus to detect the edge position of transparent sheets that would otherwise be invisible.
Solution Approach 2:
The reflective member changes the optical properties of the detection system by reflecting light in a specific pattern that makes transparent sheets detectable. This optical modification allows the detection apparatus to perceive the presence and position of transparent sheets.
2Device complexity
If the sheet width-direction position is not adjusted before skew correction, then the conveyance process is simpler, but the leading edge of the sheet may collide against the reference guide
Solution Approach 1:
The detection apparatus detects the sheet edge position and the control unit adjusts the rotary member pair position before the sheet reaches the obliquely conveying portion and reference guide. This preliminary positioning action prevents potential collisions during skew correction while maintaining a relatively simple overall system.
3Manufacturing precision
If the rotary member pair is moved based on detection results, then precise alignment is achieved, but the system cannot handle transparent sheets that cannot be detected
Solution Approach 1:
The reflective member serves as a mediator that enables the detection apparatus to detect transparent sheets. By reflecting light onto the transparent sheet, it creates a detectable optical signal that allows the control unit to calculate and adjust the rotary member pair position for precise alignment of transparent sheets.
Solution Approach 2:
The system changes the optical parameters of the detection environment by introducing the reflective member. This parameter change in the optical field allows the detection apparatus to detect transparent sheets and enables precise alignment through control unit calculations based on the detected positions.
Data Source
AI summary
A sheet conveyance apparatus includes a rotary member pair, a moving unit configured to move the rotary member pair in a width direction orthogonal to a sheet conveyance direction, an abutment member, an obliquely conveying portion, a detection portion, and a control unit. The control unit is configured to execute (1) a first mode of controlling the moving unit such that the rotary member pair is moved in the width direction based on a detection result of the detection portion before the sheet arrives at the obliquely conveying portion, and (2) a second mode of controlling the moving unit such that the rotary member pair is moved in a second direction regardless of a detection result of the detection portion in a state where the sheet is nipped by the rotary member pair and before the sheet arrives at the obliquely conveying portion.