Interlaced Scanning Memory Controller for Image Forming Apparatus
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Solution Overview
Problem
Conventional image forming devices are not designed to perform interlaced scanning efficiently, leading to complex memory accesses when trying to expose a photosensitive member with two or more scan lines worth of line data, as the order of raster image data in the page memory does not match the order of data for exposing the photosensitive member.
Innovation Solution
An image forming apparatus is designed with a photosensitive member, laser emitting members, an incident optical system, a deflector, a scanning optical system, an optical sensor, a page memory, and a line memory, where the memory controller reads adjacent sets of line data from the page memory, writes them to the line memory, and outputs unadjacent sets of line data separated by multiple scan lines to the laser emitting members for interlaced scanning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If interlaced scanning is performed with conventional memory configuration, then exposure efficiency is improved, but memory access complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-arranging line data in the line memory according to interlaced scanning requirements before the actual scanning process. The memory controller pre-processes and reorganizes raster image data from sequential order to interlaced order, so that when interlaced scanning occurs, the data is already in the correct sequence, eliminating the need for complex real-time memory access operations during scanning.
Solution Approach 2:
The patent introduces an intermediary component - the memory controller - that acts as a mediator between the page memory and the scanning system. This memory controller performs data reorganization and buffer management, converting sequential raster data into interlaced scan data format. By placing this intermediary layer, the system achieves interlaced scanning without requiring complex direct access operations, as the memory controller handles the complexity of data reordering.
2Manufacturing precision
If data is read from page memory in exposure order, then exposure accuracy is improved, but data handling complexity increases
Solution Approach 1:
The line memory serves as an intermediary buffer between the page memory and the scanning output. It temporarily stores and reorganizes line data according to interlaced scanning requirements. This intermediary buffer allows the system to read data sequentially from page memory while outputting in interlaced order, maintaining exposure accuracy without requiring complex real-time data reordering operations.
Solution Approach 2:
The system performs preliminary data organization by pre-filling the line memory with appropriately sequenced data before the scanning operation begins. This pre-arrangement ensures that data is ready in the correct interlaced sequence, maintaining exposure accuracy while simplifying the actual scanning data handling, as no complex reordering is needed during the exposure process.
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
This configuration allows for efficient exposure of the photosensitive member in a single scan based on two or more scan lines worth of line data during interlaced scanning, reducing memory access time and simplifying data handling.
Implementation Method 1
N laser emitting members (N being a natural number of two or more)
Implementation Method 2
a deflector, configured to deflect and cyclically scan each beam from the incident optical system
Implementation Method 3
a scanning optical system, configured to form on the photosensitive member N beam spots by N beams deflected by the deflector
Implementation Method 4
an optical sensor, configured to detect a beam which is deflected and scanned by the deflector to output a detection signal
Data Source
AI summary
In an image forming apparatus, a scanning optical system forms on a photosensitive member N beam spots. Each beam spot scans along a scan line on the photosensitive member for one cycle. A center-to-center distance of any neighboring two beam spots is separated by M scan lines. M is a natural number larger than or equal to two. For each cycle, the memory controller reads adjacent sets of line data for N scan lines from the page memory, writes the adjacent sets of line data for N scan lines to the storage areas identified by a plurality of successive addresses of the line memory, selects addresses identifying storage areas storing unadjacent sets of line data having non-successive two scan lines separated by M scan lines; and outputs the unadjacent sets of line data stored in the storage areas identified by the selected addresses to the N laser emitting members.