Ricoh Company, Ltd.

Hideyuki Makita

Tetsuro Hirota

Yoshihisa Ohta

Shuzo Matsumoto

Taeko Murai

Takahiro Yoshida

Tsutomu Sasaki

Satoru Tobita

Osamu Naruse

Kiyoshi Yamaguchi

Mitsumi Fujii

Takafumi Sasaki

Tomoaki Nakano

Kenichiroh Hashimoto

Tomohiko Koda

Michio Umezawa

Kunihiro Yamanaka

Shinichi Kakuda

Ryouta Matsufuji

Kunihiro Miura

Tadashi Mimura

Masayuki Iwase

A liquid ejection head includes nozzles, separate chambers, a common chamber, inlet portions, a filter unit, and ribs. Droplets of liquid are ejected from the nozzles. The separate chambers are communicated with the nozzles. The inlet portions are communicated with the corresponding separate chambers. Liquid is supplied from the common chamber to the separate chambers through the inlet portions. The filter unit is disposed between the inlet portions and the common chamber to filter liquid in an area across the separate chambers in a first direction in which the nozzles are arrayed. The ribs are disposed in the filter unit at intervals corresponding in size to at least two of the separate chambers in the first direction to partition the filter unit. The inlet portions are communicated in the first direction with each other in at least one portion of each of the inlet portions facing the filter unit.

Liquid ejection head, liquid-droplet ejection device, and image forming apparatus

An image forming apparatus is disclosed that includes a liquid discharger including a liquid discharge head configured to discharge a droplet of liquid so as to form an image. The liquid discharge head includes multiple individual channels communicating with corresponding nozzles from which the liquid is discharged; a common channel configured to supply the liquid to the individual channels; a deformable member configured to form at least one wall face of the common channel; and a vibration damping member formed of a viscoelastic material, the vibration member being provided in contact with the deformable member.

Image forming apparatus

An ink jet printing apparatus includes an ink jet head having a plurality of nozzles for respectively ejecting ink drops, a plurality of ink chambers communicating with the nozzles, and a plurality of electromechanical conversion elements corresponding to the respective nozzles. The volume of the ink chamber of the non-drive channel is increased by the influence of the drive channel adjacent thereto, and thereby undesired ejection of the ink drop occurs. To solve this problem, a drive energy set for ejecting the ink drop is applied to the piezoelectric elements of the drive chambers n&minus;1, n&plus;1 and a reduced drive energy set for not ejecting the ink drops is applied to the piezoelectric element of the non-drive channel n.

Ink jet printing apparatus

An ink jet printing head includes: a plurality of piezoelectric actuators arranged in rows on a substrate, each row including first piezoelectric elements and second piezoelectric elements which are alternately arrayed along the row, the first piezoelectric elements being actuatable to apply a compressive force to ink in accordance with print signals, the second piezoelectric elements being fixed and not actuated; and an ink chamber unit which includes ink chambers located above the first piezoelectric elements and containing ink. The ink chamber unit includes: an oscillation plate including diaphragm portions which are connected to the first piezoelectric elements and independently deformable in a direction perpendicular to the substrate by the first piezoelectric elements when actuated; and a nozzle plate which includes nozzles being located above the diaphragm portions and opened to the ink chambers, so that ink drops are respectively forced out from the nozzles when the first piezoelectric elements are actuated.

Ink jet printing head

Growing community of inventors

Yokohama, Japan

Hideyuki Makita