Ricoh Company, Ltd.

Mikio Kamoshita

Koichi Kudo

Makoto Komatsu

Mitsuru Takahashi

Toshiyuki Andoh

Atsushi Mori

Yasufumi Yamada

Minoru Takahashi

Masahiko Kato

Hideaki Kibune

Takuroh Kamiya

Kaoru Kataoka

Masaru Kumagai

Tomiko Takahashi

An image forming apparatus includes a latent image carrier carrying a latent image, a developing device visualizing the latent image utilizing a two-component developer, a supply device supplying toner according to a change in toner density in the two-component developer inside the developing device, and a control device having an input side connected to a density sensor detecting a value of the toner density and an image information acquisition device acquiring information on an image formed on the latent image carrier, and an output side connected to a driving device driving the supply device. When the detected value is higher than a target value of the toner density stored by the control device, the control device performs control to stop the driving device or drive the driving device to supply toner in an amount less than a combined toner supply amount of first and second toner supply amounts.

Developing device and image forming apparatus

In a belt moving device that is capable of reducing belt speed fluctuation and positional deviation from a target belt position in a sub-scanning direction and performing highly precise position control in a main scanning direction, and an image forming apparatus that uses this belt moving device to prevent color shift in both the main scanning direction and sub-scanning direction of a formed image such that a high-quality image can be formed, belt shift control means reduce shift position variation within a single round trip of an endless belt by feeding back a target value for canceling out the shift position variation within a single round trip of the endless belt and feeding forward a value obtained by multiplying an inverse transfer characteristic of moving means by a transfer characteristic of a target value of the moving means in relation to the control content of the moving means.

Belt moving device and image forming apparatus using same

A belt moving device of the present invention includes a drive shaft for moving the belt and a drive transfer line for transferring the output torque of a motor to the drive shaft. A marker sensor senses a marker positioned on the belt to thereby determine the position of the belt in the direction of movement. A rotation condition sensor senses the rotation condition of the drive shaft. A first correction information generating circuit generates, based on the output of the marker sensor, correction information for correcting the position of the belt. A second correction information generating circuit generates, based on the output of the rotation condition sensor, correction information for correcting the rotation condition of the drive shaft. A controller controls the movement of the motor in accordance with the correction information output from the first and second correction information generating circuits.

Belt moving device and image forming apparatus including the same

An image forming apparatus including a drum, an optical scanning mechanism, a development mechanism, an intermediate transfer member, movement detecting mechanisms, and a controller. The intermediate transfer member is rotated in synchronism with a rotation of the drum and receives color toner image multiple times to form thereon a composite color toner image including multiple images of different color toners overlaying one to another. The movement detecting mechanisms detect respective movements of the drum and the intermediate transfer member. The controller controls respective rotations of the drum and the intermediate transfer member with results of respective detection performed by the movement detecting mechanisms.

Method and apparatus for color image forming capable of performing a precise synchronization between toner image forming per color and its overlaying

An original image reading apparatus comprises an exposure optical system including a scanner optical system which can perform go and return operations, a scanner driving motor which drives said scanner optical system, velocity detecting means for detecting a moving velocity of said scanner optical system and position detecting means for detecting the position of said scanner optical system. In the apparatus, return control is performed which is control of returning said scanner optical system after an original image reading scan has been finished. A target velocity is calculated from a residual distance from a current position of said scanner optical system to a target reference position. Target acceleration is used as feedforward. Velocity control is performed so that detected velocity follows the target velocity.

Control method of scanner optical system of original image reading

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Tokyo, Japan

Mikio Kamoshita