Ricoh Company, Ltd.

Hitachi Printing Solutions, Ltd.

Shinya Tomita

Satoru Tobita

Toshitaka Ogawa

Makoto Nakura

Satoru Tao

Naoto Ueda

Yoshinari Onuma

Masanori Takayasu

Takemasa Ryo

An image forming apparatus includes an image carrier, a transfer unit to transfer the image onto a recording medium, a torque limit unit to transmit drive force to the transfer unit at a torque less than the torque for transmitting drive force, and drive the transfer unit to rotate at a circumferential velocity higher than that of the image carrier when the image carrier and the transfer unit are in contact with each other, and a drive unit to output drive force to drive the transfer unit such that the transfer unit rotates at a circumferential velocity lower than that of the image carrier when the image carrier and the transfer unit are separate from each other, and the transfer unit rotates at a circumferential velocity higher than that of the image carrier when the image carrier and the transfer unit are in contact with each other.

Image forming apparatus

A belt traveling unit includes an endless belt, a drive roller and a correction roller, a driving unit, a correction unit, a contact member, a position detector and a regulating member. The endless belt is spanned between a plurality of rollers. The driving unit rotates the drive roller to drive the belt. The correction unit adjusts a tilt angle of the correction roller to correct drifting of the belt in the width direction thereof. The contact member is rotatable in conjunction with traveling of the belt in the width direction thereof. The position detector detects a position of the contact member to detect a position of the belt in the width direction thereof. The regulating member is located at a position where the position detector does not misdetect the position of the belt when the contact member rotates.

Image forming apparatus including belt traveling unit which detects drifiting of belt postion

An inkjet head is formed with a nozzle, a pressure chamber, a plurality of restrictors, and a common ink chamber. Because the plurality of restrictors are formed in the inkjet head, it is possible to increase a fluid resistance of the restrictors without decreasing the Helmholtz resonant frequency. Accordingly, the inkjet head can be driven at a high frequency while preventing residual pressure wave affecting a subsequent ink ejection.

Inkjet head formed with a plurality of restrictors and inkjet printer including the same

An ink jet recording head that enables a reduction in the amount of piezoelectric plate consumed, so that costs can be lowered, without lowering efficiency of piezoelectric actuators, even if the piezoelectric actuators are only roughly fixed to the housing, and that also enables accurately and easily positioning the piezoelectric actuators with respect to a diaphragm that defines an ink channel. Assuming that mB is the mass (kg) of the base to which the piezoelectric actuator is fixed and T is the rising edge time (s) of the drive signal that drives the piezoelectric actuator , the spring modulus determined from mB and T is 2&times;mB/T &gE;5.0 e (N/m). Therefore, the displacement of the piezoelectric actuator can be efficiently transmitted to the ink chamber regardless of the spring modulus of the adhesive agent used to fix the base to the housing.

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Hitachinaka, Japan

Shinya Tomita