Kyocera White Line Compensation Technology: Quality Restoration Solution for Inkjet Printing

1. Technical Background: The Causes and Impact of the White Line Problem

"White line" is a common quality defect in inkjet printing, mainly originating from two types of scenarios:

1. Hardware defects cause: nozzle blockage, deviation or weakening of the print during printing, resulting in linear gaps in the ink jet;

2. Mechanical feed deviation: When the paper leaves the feed roller, due to excessive feed, there is a blank gap in the printing area.

This kind of problem directly affects the consistency of printed materials, especially in high-precision printing scenarios such as coated paper, which may increase the frequency of nozzle cleaning and waste of consumables.

II. Core Technology Proposal: Dual Logic of Hardware Optimization and Intelligent Compensation

Konica Minolta solves the white line problem with a “Prevention + Repair” dual-layer strategy, key technology paths include:

(1) Hardware foundation: Strengthening the stability of the nozzle and ink supply system.

1. High-precision nozzle design

The Kyocera 80K series nozzle improves the accuracy of the jet, reducing the causes of color difference and white line from the source. Its piezoelectric jet structure can accurately control the landing point of the ink droplet, and in combination with the "hybrid dot" technology of partners such as Fangzheng, it reduces the blank gaps in the tone flat net.

2. Ink supply system coordination

When paired with the sixth-generation closed-loop ink delivery system, the probability of nozzle clogging is reduced by continuously recycling ink, eliminating the underlying conditions for white lines to occur at the hardware level.

(II) Intelligent Compensation: Dynamic Control and Defect Repair Algorithms

1. Mechanical conveyor speed regulation (CN1496849A patent)

To compensate for the white line caused by paper feed deviation, the system achieves it through three major modules:

◦Location sensing: The file position sensor detects the moment the paper arrives at the reference position;

◦Data prediction: the storage unit pre-stores the information of the white line high occurrence position corresponding to different paper sizes;

◦Dynamic speed control: Temporarily reduce the speed of the feed roller or stop the machine for a short time when the white line is about to be generated, to correct the problem of excessive conveying.

For example, the system can predict the time point when the paper tail detaches from the roller when printing on A4 paper, and decelerate in advance to avoid blank production.

1. Compensation for ink bloom caused by a defective nozzle (CN111196088B patent)

For the white line caused by nozzle failure, the strategy of "adjacent nozzle coordination + utilization of defective nozzles" is adopted:

◦Non-stop defect nozzle: control the nozzle to continue spraying a small amount of ink for the nozzle that is weakened or slightly offset;

◦Ink drop volume control: The volume of ink drop is increased by the nozzle directly adjacent to the nozzle, and then decreased by the next adjacent nozzle, using the ink cohesion effect to form an “ink bridge” to fill the gap;

◦Dynamic Adaptation: Adjust the compensation frequency according to the ink type and substrate (e.g., compensate 1 point for every 10 pixels), avoiding excessive compensation that could form black lines.

(III) System-level closed-loop: Quality control through software-hardware co-design

Konica Minolta optimizes the entire supply chain with a combination of "Print head+ink+detection system".

•Adopt the "Ji Cai ink + Kyocera nozzle" compatible combination to improve the adhesion and diffusion characteristics of ink on media such as coated paper;

• The interlinked online detection system identifies the white line in real-time, triggering the automatic compensation process, reducing the frequency of nozzle cleaning to 2-3 times per shift (for coated paper scenarios).

III, Application Practice and Technological Advantages

1. Core application scenarios

Mainly serving the digital printing field, it is especially prominent in the mixed production of coated paper and offset paper. Equipment manufacturers such as Fangzheng have achieved a balance of "high resolution + low loss" by integrating Kyocera technology, adapting to high-precision demands such as book publishing and commercial posters.

2. Key advantages comparison

IV. Technological Limitations

Current technology still has limitations at the boundaries: for example, a completely failed nozzle cannot be compensated by the coalescence effect, and ink type must match the coalescence characteristics.