Image forming apparatus

摘要

The image forming apparatus includes a liquid ejection head and an ejection control device. The liquid ejection head includes: a large nozzle and a small nozzle performing ejection of droplets of liquid, the droplet ejected from the large nozzle having volume larger than the droplet ejected from the small nozzle; and liquid flow channels corresponding to the large and small nozzles, the ejection of the droplets from the large and small nozzles being induced by formation of bubbles in the liquid in the corresponding liquid flow channels caused by applied thermal energy. The ejection control device controls the ejection of the droplets in such a manner that a product of a Reynolds number and a Weber number for the droplet ejected from the large nozzle and a product of a Reynolds number and a Weber number for the droplet ejected from the small nozzle are equal to each other. Each of the products is defined as: $\mathrm{Re}x\mathrm{We}=\frac{{\mathrm{rho}}^{2}x{V}^{3}x{D}^2}{\mathrm{mu}x\mathrm{gamma}}.$ where Re is the Reynolds number for the droplet, We is the Weber number for the droplet, rho is a density of the liquid, V is a flight speed of the droplet, D is a diameter of the nozzle from which the droplet is ejected, mu is a viscosity of the liquid, and gamma is a surface tension of the liquid.