Image Forming Apparatus Leading Edge Detection
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Solution Overview
Problem
Existing image forming apparatuses face challenges in accurately detecting the leading edge of a paper sheet at close distances, which limits printing speed and complicates registration adjustment due to the need for multiple sensors and time gaps during paper sheet detection.
Innovation Solution
An image forming apparatus with a second paper sheet sensor positioned upstream from the first sensor allows for accurate detection of the leading edge, even at small distances between paper sheets, and simplifies the registration adjustment process by using either sensor based on conveying speed and distance conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single paper sheet sensor is mounted on the carriage, then the device complexity is low, but the productivity decreases due to time gaps between scanning completion and leading edge detection
Solution Approach 1:
The leading edge detection sensor is positioned upstream of the carriage to detect the leading edge of the paper sheet before the carriage arrives. This preliminary detection allows the system to prepare for the next printing operation without waiting for the carriage to complete its scanning motion, thereby eliminating the time gap and improving productivity
2Productivity
If multiple paper sheet sensors are provided, then the productivity increases by enabling detection at small distances, but the device complexity increases due to multiple sensors requiring adjustment
Solution Approach 1:
The leading edge detection sensor serves multiple functions: it detects the leading edge position, determines when to start the next printing operation, and enables the carriage to move to the next position. This multi-functionality allows the system to achieve high productivity with a single sensor rather than multiple sensors, thereby reducing device complexity while maintaining high printing speed
3Productivity
If the distance between paper sheets is reduced, then the productivity increases, but the measurement precision decreases making accurate detection difficult
Solution Approach 1:
The leading edge detection sensor acts as an intermediary element positioned between the paper sheet and the carriage. It detects the leading edge of the paper sheet at a distance and provides this information to the control system, enabling accurate detection even when paper sheets are closely spaced. This intermediary sensor allows the system to maintain measurement precision while reducing the distance between paper sheets for higher productivity
Data Source
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AI summary
An image forming apparatus that forms an image on a recording medium by conveying the recording medium in a direction orthogonal to a scanning direction of a carriage having a recording head includes a first detecting unit mounted on the carriage and configured to detect the recording medium; a second detecting unit placed upstream from the first detecting unit in the direction that the recording medium is conveyed and configured to detect the recording medium; and a control unit configured to control operations of the image forming apparatus based on a detection result from the first detecting unit or the second detecting unit.