Ricoh Company, Ltd.

Toshifumi Kato

Toshiharu Murai

Koichiro Jinnai

Takahisa Koike

Kazumi Ishima

Takao Fukazawa

Tadashi Itoh

Yutaka Ebi

Tositaka Hirata

Yohei Ikezu

A deflection control ink jet recording apparatus is capable of compensating for dislocation of dots at all the deflection steps. A deflection amount is adjusted with respect to two points to determine a correlationship between the amplification gain, charge code and deflection amount, so that an amplification gain and a charge code free from dislocation is set for each deflection step. A charge code compensation value is detected to add it to or subtract it from a predetermined charge code assigned to each deflection step, thereby setting a charge voltage code to be assigned to each deflection step in a printout operation.

Deflection control ink jet printing apparatus

An ink jet head prints an image by superposing individual dot matrices of at least two colors. A computing unit receives electrical input signals representing the image and generates and feeds corresponding electrical signals representing the individual matrices of the at least two colors to the head means for printing. The computing means includes matrix generator means for generating the matrices in such a manner that the total number of dots to be printed in all of the matrices is limited to a first predetermined value which is less than the maximum possible total number of dots which can be printed in all of said individual dot matrices, and the total number of dots to be printed in the matrices which are formed by superposed dots of different colors is limited to a second predetermined value which is less than said first predetermined value.

Multicolor ink jet recording apparatus having means for preventing

A sheet clamping device is provided which is used to clamp both the leading and the trailing end of a sheet while the sheet is being disposed around the peripheral surface of a drum rotating in a given direction. The drum is provided with a front and a rear claw which are adapted to clamp the leading and the trailing end of the sheet, respectively, and which are urged to bear against the peripheral surface of the drum. The claws are operated to open or close in response to respective claw operating means. After a sheet has its leading end clamped to the drum surface by means of the front claw, combing urges the sheet against the drum surface while combing it, and the trailing end of the sheet is clamped to the drum by means of the rear claw.

Sheet clamping device

An electrostatic latent image is formed on a photoconductive or dielectric image carrier by a technique in which the image carrier is charged and exposed utilizing the photoconductivity, or by a technique in which the surface of the image carrier is directly and selectively charged with a stylus or a pin tube. The latent image is either directly developed or subjected to reversal development to form a positive or a negative visual image on the carrier. The direct development or reversal development may utilize one of dual toners which are charged to opposite polarities in a selective manner, or may employ a single component powder toner which is forcedly charged to a given polarity. the positive or negative visual image is electrostatically transferred onto a record sheet. The polarity of the voltage utilized during the transfer is switched depending on the polarity to which the toner which forms the visual image to be transferred is charged.

Growing community of inventors

Tokyo, Japan

Toshifumi Kato