Image Copying Device Overlapping Front Rear Surface Reading
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Solution Overview
Problem
Conventional image copying devices with automatic document feeders lack efficiency in copying documents with images on both sides, as they require sequential reading and storage of front and rear surfaces, leading to prolonged processing times and high RAM storage demands.
Innovation Solution
An image copying device with a reading portion, storage portion, and image forming portion that reads and stores images from one surface of documents sequentially, allowing image formation to start before all rear surfaces are read, optimizing storage capacity and reducing processing time by linking and managing image data for both surfaces efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If image data for front and rear surfaces of all documents is stored in RAM before forming images, then complete document copying is achieved, but processing time becomes excessively long
Solution Approach 1:
The system performs preliminary reading and storage of front surface image data in RAM before rear surface reading is completed. This allows image formation to begin in advance using the stored front surface data, rather than waiting for all reading operations to finish. The controller manages this by storing front surface data as it is read, then initiating image formation while rear surface reading continues, thus overlapping operations to reduce total processing time.
2Reliability
If image data for front and rear surfaces of all documents is stored in RAM, then all document data is available for copying, but RAM storage capacity requirements increase significantly
Solution Approach 1:
The system extracts and processes only the necessary image data for current copying operations rather than storing all document data simultaneously. By reading front surfaces first and storing only that data in RAM, then initiating image formation, the system avoids the need to hold all front and rear surface data in memory at once. This extraction approach reduces RAM requirements while maintaining data availability for the copying process.
3Device complexity
If sequential reading of front surfaces followed by sequential reading of rear surfaces is performed, then reading organization is simplified, but overall copying efficiency decreases
Solution Approach 1:
The system maintains continuous useful action by overlapping the reading process with the image formation process. While the reading portion continues to read rear surfaces sequentially, the image forming portion simultaneously forms images using the front surface data already stored in RAM. This continuity eliminates idle waiting time between reading and formation operations, thereby improving copying efficiency without complicating the sequential reading organization.
Data Source
AI summary
A copy machine completes the reading in of the front surfaces of a plurality of documents, before starting reading in of the rear surfaces of the documents, and starts forming images before the reading in of the rear surfaces of all the documents has been completed. After the front surfaces of all the plurality of documents have been read in, the reading of the rear surfaces starts. It takes a period of time from a time T2 to a time T7 to read in image data of a quantity (Q2−Q1) from the rear surface of one document as apparent from a line segment 200a that is indicative of the speed at which the read-in image data is stored. The timing of printing start is offset to ensure that the line segment 200a and the line segment 300b do not intersect with each other. This makes it possible to start printing based on image data for the rear surface of the document while the reading of the subject surface of the subject document. It is possible to prevent the image data from running out regardless of the difference between the storing speed and the read-out speed.