Ink Feeding Control for Continuous Printing
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Solution Overview
Problem
Existing image forming apparatuses face low printing speed due to the need to stop printing for tank filling, as the precise detection of ink levels in the head tank is not accurately maintained, leading to potential over or underfeeding of ink, which affects negative pressure and ink consumption.
Innovation Solution
An image forming apparatus with a displacement member in the head tank that is detected by both a carriage-mounted detector and a separate apparatus detector, allowing the feed controller to calculate a difference displacement amount and adjust ink feeding accordingly to maintain optimal ink levels without stopping the printing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the carriage moves to the tank filling position to detect the displacement member and open the tank for ink feeding, then the ink level in the head tank can be precisely detected and controlled, but the printing process must be stopped, resulting in low printing speed
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the displacement amount corresponding to the ink consumption volume in a lookup table before printing operations begin. During printing, the feed controller simply retrieves the pre-calculated displacement amount based on the detected ink consumption, avoiding the need to stop printing for real-time displacement measurement. This resolves the contradiction by preparing detection reference data in advance, enabling fast ink feeding control during printing while maintaining precise ink level detection capability.
2Productivity
If the ink feeding is controlled based on counted droplet discharge to calculate consumption, then ink can be fed in equivalent amount, but the tank filling position detection is not precise, causing excessive negative pressure or low negative pressure
Solution Approach 1:
The patent implements feedback by continuously monitoring the actual displacement amount of the displacement member during ink feeding and comparing it with the target displacement amount calculated from ink consumption. The feed controller uses this feedback to adjust the ink feeding amount in real-time, ensuring the ink level is precisely controlled within the optimal range. This resolves the contradiction by using actual displacement feedback to correct any deviations from the target ink level, maintaining precise control while enabling continuous printing.
Solution Approach 2:
The patent replaces the mechanical displacement detection system with an optical detection system using a detector that measures the position of the displacement member optically. This substitution provides more precise and reliable displacement measurement compared to mechanical methods, enabling accurate ink level control. The optical detection system can quickly and accurately measure the displacement amount without mechanical contact, resolving the precision issue while supporting continuous operation.
3Productivity
If a detector and driver are installed on the carriage to control ink feeding, then ink can be fed during printing, but the carriage weight increases and the carriage size enlarges
Solution Approach 1:
The patent extracts the ink feeding control function from the carriage and relocates it to the main body of the image forming apparatus. The feed controller, displacement member, and detector are all positioned outside the carriage structure. This extraction eliminates the need to install additional detectors and drivers on the carriage, thereby reducing carriage weight and size while maintaining the capability to perform ink feeding during printing operations. The carriage only needs to carry the essential printing components, improving its performance characteristics.
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 solution enables continuous ink feeding during printing by accurately determining the difference displacement amount, ensuring the head tank remains within optimal ink levels, thereby improving printing speed and efficiency by preventing excessive negative pressure or ink depletion.
Implementation Method 1
a flexible (film) member forming a facing of an ink container containing an ink
Implementation Method 2
a negative pressure generator generating a negative pressure to prevent the ink from exuding or dripping from a nozzle of the recording head
Data Source
AI summary
An image forming apparatus filling its head tank with an ink while printing even when a detector of the apparatus detects the filled tank by detecting a displacement member being displaced according to an amount of the ink remaining in the head tank.