Image Forming Apparatus Edge Detection Marginal Area Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image forming apparatuses face challenges in accurately detecting the position of a sheet during conveyance, leading to errors in image formation due to variations in conveyance speed or sheet slip, which can result in excessive marginal areas being required for pattern detection or unnecessary consumption of sheet space.
Innovation Solution
An image forming apparatus with a detection unit, forming unit, reading unit, and memory that specifies the edge of the recording material and examination pattern area based on conveyed image data, allowing for reduced marginal areas by controlling the reading and examination of the pattern area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sufficiently large marginal area is provided before the examination pattern, then the examination pattern can be detected accurately without erroneous detection, but a large area of the sheet is consumed for an application purpose other than image recording
Solution Approach 1:
The patent changes the parameter of reading speed during examination pattern detection. By reading the examination pattern at a speed different from the normal conveyance speed (specifically, reading while maintaining a moving speed as disclosed in Japanese Patent No. 5474173), the system can accurately detect the pattern position without requiring a large marginal area, thus resolving the contradiction between detection accuracy and sheet area consumption
Solution Approach 2:
The patent replaces the mechanical approach of providing physical marginal space with an optical/electronic approach. Instead of relying on physical distance (marginal area) to prevent erroneous detection, the system uses controlled reading at specific moving speeds to accurately identify the examination pattern position, substituting mechanical spacing requirements with optical detection methodology
2Measurement precision
If the sheet length is increased to provide sufficient marginal area, then pattern detection accuracy improves, but the conveyance error caused by variation in conveyance speed or sheet slip increases
Solution Approach 1:
The patent changes the reading speed parameter during pattern examination to compensate for conveyance variations. By reading the examination pattern while maintaining a controlled moving speed, the system can accurately detect pattern positions even on shorter sheets, thereby resolving the contradiction between detection accuracy and conveyance precision without requiring increased sheet length
Data Source
AI summary
An image forming apparatus comprises a detection unit that detects that a recording material is conveyed to a predetermined position on a conveyance path; a forming unit that forms an examination pattern at a defined position of the recording material; a reading unit that reads an image on the conveyance path when the recording material is being conveyed; a memory that saves read image data during a predetermined period defined based on a detection timing of the detection unit; a specifying unit that specifies an edge of the recording material by detecting an area corresponding to the conveyance path in the image data saved in the memory, and specifies an examination pattern area corresponding to the examination pattern based on the specified edge and the defined position; and an examining unit that examines the examination pattern area.