Research On High Speed Ink Drop Measurement System And Inkjet Compensation Method

With the development of inkjet printing technology,new applications have emerged with new demands.Aiming at the problems of reliability and uniformity of inkjet printing technology,this paper proposes a solution based on high-speed flying droplet measurement system.The vertical cavity surface emitting laser and photodiode are used to convert the dynamic behavior of the flying droplet into electrical signals,suppress the mode hopping and greatly improve the signal-to-noise ratio through the slit,so that the signal gain is 4.7×105,thereby obtaining various jetting parameters during the flight of the ink droplet.The system has a sampling frequency of 20MHz and a single nozzle measurement time as low as 20ms,which can meet the needs of all ink droplet measurements.The system can be used not only in thermal bubble inkjet printheads mentioned in this thesis,but also compatible with other types of inkjet printheads.At the same time,due to the advantages of green technology,low cost and high speed of thermal bubble inkjet printing technology,this thesis has carried out experimental research on thermal bubble inkjet printing technology based on the self-developed high-speed flying droplet measurement system.Considering the influence of various factors on the flying behavior of ink droplets,systematically studied the voltage,pulse width,frequency,temperature,printing pattern and other responses,innovatively studied the problem of ink droplet jitter.Combined with the thermal bubble nucleation observation experiments,in depth analysis of the root cause of the printing quality defects in inkjet printing has been carried out.According to the data summarized in the ink drop measurement experiment,an optimized model for precise control of ink droplets is established.By adjusting the driving parameters and printing parameters,a comprehensive inkjet compensation control method is established to greatly improve the reliability and uniformity of inkjet printing.The innovation aspects of this thesis include:(1)Establish a high-speed flying droplet measurement system.The system is capable of automated,high-efficiency,high-precision measurement of droplet flight dynamics.Compared with the other four ink droplet measurement methods,it is the only method that can achieve both high precision and high efficiency.(2)Detailed test experiments are conducted on two domestic TIJ printheads.The relationship between the flight characteristics and working conditions is systematically studied,and the thermal bubble micleation process is further studied,which essentially explained the physical mechanism that constitutes these features.(3)A set of ink performance test scheme based on the high-speed flying droplet measurement system is established.Compared with the traditional ink testing scheme,it pays more attention to the stability and uniformity of ink droplet ejection,which provides an effective test standard for ink research and greatly improves the development efficiency of ink.(4)Based on the high-speed flying droplet measurement,a complete inkjet compensation control method is proposed and verified,which solved the problem of reliability and unifornity of current inkjet printing technology and laid the foundation for the development of high-end applications for inkjet printing technology.