Ricoh Company, Ltd.

Mayumi Ohori

Ken Amemiya

Masaru Tanaka

Haruji Mizuishi

Hiroshi Mizusawa

Kenzo Tatsumi

Hideki Zenba

Hiroyuki Ohkaji

Toshitaka Yamaguchi

Hideki Zemba

Fumio Kishi

Noriyuki Usui

Kenzou Tatsumi

Hiroshi Yoshinaga

Shigeru Watanabe

Takeo Suda

Kouji Ishigaki

Hiroyuki Okaji

A control system for an image forming device includes a sensor mounted on an optical path unobstructed by elements that are subject to wear for detecting a time varying signal representing reflected light from both a photoconductive element and a transfer sheet internal to the image forming device, a memory storing reference values, and a controller to control an image forming operation based on the reference values stored in the memory and the time-varying signal received from the sensor. The controller reads the time-varying signal from the sensor and compares the time-varying signal read to the reference values to determine a condition of the image forming device.

Image forming apparatus

An image forming apparatus with a sensing control system having an optical sensor and a control device. A detected object is recognized by using the difference of an output characteristics correspond to a quantity of reflected light. Thus, one or more detected objects may be precisely detected by the one optical sensor.

Image forming apparatus having a sensor for sensing an amount of reflected light from both a photoconductive element and a paper

An image-forming apparatus includes an image-bearing device that holds an electrostatic latent image and a toner image thereon, and a developer container that contains and agitates a developer having at least a toner. The image-forming apparatus also includes a developer-bearing device that carries the developer to develop the electrostatic latent image on the image-bearing device, and a density sensor that detects an optical density of a surface of the image-bearing device and a toner image on the image-bearing device. Further, the image-forming apparatus includes a developer seal that seals the developer in the developer container, wherein the seal is disposed between the developer container and the developer-bearing device, and an actuator configured to actuate the developer container and the developer-bearing device. The image-forming apparatus still further includes a control device that determines whether the developer seal is removed according to information on the optical density of the toner image output by the density sensor.

Image-forming apparatus having a seal for a developer and a method for detecting a removal of the seal

An image forming apparatus transfers a toner image from a photoconductive image carrier to a recording medium with a transfer roller and senses the density of a particular toner pattern formed on the image carrier with an optical sensor. A voltage of a first polarity opposite the polarity of the toner is applied to the transfer roller when the toner image is to be transferred to the recording medium. A voltage of a second polarity identical to the polarity of the toner is applied to the transfer roller when the toner pattern is to be moved between the image carrier and the transfer roller. Thus, even when a toner pattern is brought to the transfer roller, the transfer roller is not released from the photoconductive element.

Image forming apparatus with a voltage applying unit for image transfer

An image forming apparatus includes an image carrier and a developing device to develop a latent image formed on the image carrier by applying two-component developer, including toner, onto the latent image. The developing device includes a developing part containing the two-component developer and a developer stirring device to stir the two-component developer. A toner supplying device supplies toner to the developing part of the developing device, and a toner density detection device detects a toner density of the two-component developer in the developing device. A toner control device calculates a difference between an output value VT of the toner density detection device and a criterion value VTref for controlling the toner density of the two-component developer and controls the toner supplying device based upon the difference. An image density detection device detects an image density of a criterion image formed on the image carrier, and a criterion value correcting device corrects the criterion value VTref based upon an output value of the criterion image density detection device. A decision as to whether to stir the developer in the developing device with the developer stirring device is made based upon a difference between the criterion value VTref and the output value VT from the toner density detection device and an output value of the criterion image density detection device when an image forming operation is started.

Image forming apparatus with improved toner density control

A image forming apparatus with a sensing control system having an optical sensor and a control device. An detected object is recognized by using the difference of an output characteristics correspond to a quantity of reflected light. Thus, one or more detected objects may be precisely detected by the one optical sensor.

Image forming apparatus having a sensor for sensing an amount of

An image forming apparatus is provided, which includes an image bearing member, a transfer roller having a shaft for transferring an image on the image bearing member to a transfer sheet, a bearing mechanism for supporting the shaft, a discharging device for discharging the transfer, and a joint mechanism which mechanically connects the discharging device with the transfer roller at both ends of the shaft. Both of the transfer roller and the discharging device can be integrally detached from and attached to the image forming apparatus without detaching/attaching the bearing mechanism, by use of a handle. Therefore, an operation for replacing the transfer roller and the discharging device can be performed easily.

Image forming apparatus having detachable transfer roller and discharge

An image forming apparatus includes a charging element configured to apply a charging voltage to an image bearing member to charge the image bearing member, an optical writing device configured to form a latent image on a charged surface of the image bearing member charged by the charging element, a developer bearing member which carries developer including toner having a same polarity as that of the charging voltage to the image bearing member and which applies the toner to the latent image on the image bearing member to form a toner image when a developing bias voltage is applied thereto, and a control device which controls application of the charging voltage by the charging element and application of the developing bias voltage to the developer bearing member so as to increase an absolute value of the charging voltage to the image bearing member and an absolute value of the developing bias voltage to the developer bearing member to a predetermined value in a plurality of steps, respectively and wherein the following relation holds for each of the plurality of steps:

Image forming apparatus and method for controlling charging and

An electrophotographic image forming apparatus is disclosed which is provided within a cleaning device with a rotative conveying member for conveying a residual toner after removal thereof from a photoreceptor up to an inlet of a toner dropping path while rotating. Within the toner dropping path is disposed a toner bridge preventing member for preventing the formation of a toner bridge in the same path. The toner bridge preventing member is driven by the rotative conveying member so as to reciprocate substantially in parallel with the toner dropping direction.

Electrophotographic image forming apparatus

An image forming apparatus which is capable of adjusting toner density in response to variations of humidity. The image forming apparatus includes a toner density detector that detects the density of toner inside an image developer, a humidity detector that detects toner humidity inside the image forming apparatus, and a controller that controls a toner supplier on the basis of the toner density detected by the toner density detector and that adjusts the toner density in accordance with variations of humidity detected by the humidity detector. The humidity detector is located at a position where the humidity detector can detect humidity of air around the image developer and where the humidity detector is minimally affected by heated air.

Growing community of inventors

Kawasaki, Japan

Mayumi Ohori