Nozzle Array Timing Control for High-Speed Printing With Less Memory
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Solution Overview
Problem
Existing liquid ejection apparatuses face challenges in generating nozzle control signals based on image data while minimizing memory usage, particularly when operating at high speeds.
Innovation Solution
A liquid ejection apparatus with a first and second nozzle array, where nozzles in the second array are shifted in the first direction, allowing for the generation of nozzle drive signals based on image data using a single memory to alternately eject liquid from two nozzles, reducing memory requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If liquid ejection is performed at high speed using multiple nozzle arrays, then productivity is improved, but memory requirements increase due to the need to store and process image data for all nozzles simultaneously
Solution Approach 1:
The patent divides the nozzle array into first nozzles and second nozzles with different ejection timing. The controller selectively reads image data for either first nozzles or second nozzles from the memory based on the current ejection phase, rather than loading all nozzle data simultaneously. This segmentation of the nozzle population allows high-speed ejection while reducing peak memory requirements.
Solution Approach 2:
The patent implements preliminary reading of image data into the memory before the actual ejection process. The controller reads image data in advance and stores it in the memory buffer, then processes and ejects liquid based on this pre-loaded data. This preliminary action allows the ejection system to operate at high speed without requiring large amounts of memory to be continuously accessible during the ejection process.
2Manufacturing precision
If drive signals for multiple nozzles are generated simultaneously from image data, then manufacturing precision is improved, but device complexity increases due to additional memory resources required
Solution Approach 1:
The patent segments the nozzle control into two distinct groups (first nozzles and second nozzles) with different timing characteristics. The controller generates drive signals for first nozzles at one timing and for second nozzles at a different timing, reading image data sequentially for each group. This segmentation maintains precision by ensuring each nozzle receives appropriately timed drive signals while reducing memory complexity by processing data in smaller batches.
Solution Approach 2:
The patent employs periodic action by alternating between driving first nozzles and second nozzles in a cyclic manner. The controller periodically switches between processing first nozzle data and second nozzle data from the memory, creating a rhythmic ejection pattern. This periodic operation maintains manufacturing precision through consistent timing while reducing the peak memory burden by not all nozzles requiring simultaneous data access.
Data Source
AI summary
A carriage on which a head is mounted moves in a second direction crossing a first direction. A driving circuit is configured to output a drive signal to each of nozzles. A controller is configured to perform: storing, in a memory, image data of an image to be formed; and controlling the driving circuit to: output the drive signal for a first nozzle in the first nozzle array based on first data among one-line image data stored in the memory; and output the drive signal for a second nozzle in the second nozzle array based on second data among the one-line image data. The one-line image data is the image data for one line in the second direction in the image. The first data forms odd-numbered dots of the one line in the second direction in the image. The second data forms even-numbered dots of the one line.