Liquid ejection head
View Patent ↗The repellency increasing structure includes a substrate, if a surface of the substrate is flat, a flat surface of which shows lyophilic property with respect to a liquid having a surface tension lower than that of water and multiple recesses multiple and/or projections that are formed in the surface of the substrate. Inner walls of the recesses and outer walls of the projections are substantially parallel to a thickness direction of the substrate. The structure further includes a repellent layer that covers the recesses and the projections. In the liquid ejection head, a solution ejection surface around multiple through-holes of a ejection substrate corresponds to the surface of the substrate of the repellency increasing structure in which the recesses and/or the projections are formed. In the stain-resistant film, the substrate of the repellency increasing structure is a support film.
1. A liquid ejection head for ejecting droplets of a solution, comprising:
an ejection substrate in which multiple through-holes through which said droplets are ejected are formed; and
droplet ejection means for allowing said droplets to eject through at least one of said multiple through-holes,
wherein said ejection substrate includes a repellency increasing structure that comprises:
a substrate having a flat surface which shows lyophilic property with respect to a liquid having a surface tension lower than that of water; and
multiple recesses and/or multiple projections each having a diameter or equivalent diameter of 50 μm or less and that are formed in said surface of said substrate,
wherein inner walls of said multiple recesses and/or outer walls of said multiple projections are substantially parallel to a thickness direction of said substrate, and
wherein said repellency increasing structure is arranged in such a manner that a solution ejection surface of said ejection substrate around said multiple through-holes corresponds to said surface of said substrate of said repellency increasing structure in which said multiple recesses and/or said multiple projections are formed.
2. The liquid ejection head according to claim 1 , wherein said solution is mainly composed of an organic solvent, oil, or a liquid having a surface tension of 40 mN/m or less.
3. The liquid ejection head according to claim 1 ,
wherein said solution is prepared by dispersing charged particles, and
wherein said droplet ejection means comprises:
ejection electrodes for exerting an electrostatic force on said solution, said ejection electrodes being arranged in correspondence with the respective multiple through-holes, and
a solution guide passing through each of the multiple through-holes and extending toward a droplet ejection side of said ejection substrate,
wherein said droplets are ejected by said electrostatic force generated by said ejection electrodes.
4. The liquid ejection head according to claim 1 , wherein said droplet ejection means comprises a droplet ejection unit of a piezoelectric system or a thermal system for ejecting said droplets from said multiple through-holes of said ejection substrate, and said droplets are ejected by said droplet ejection unit.