Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Shouji Takano

Reiji Murakami

Kunihiko Miura

Masashi Kimura

Kozo Matsuyama

Koji Yukinaga

Kazutaka Takahashi

Motohiko Tanigawa

An image-forming apparatus includes a platen on which an original is placed so that a first surface of the original is positioned at an exposure area, a first sensor for detecting that a second surface of the original which is the opposite surface to the first surface has an image, and a second sensor for detecting the transmittance of the original. The image-forming apparatus also has an exposure lamp which is arranged near the platen to expose the first surface positioned at the exposure area, a voltage source coupled to the exposure lamp, a control unit for adjusting the voltage applied from the voltage source to exposure lamp corresponding to the transmittance in the case that the first sensor detects that the second surface has an image, and an image-forming unit for forming a copying image on the basis of the light image.

Image-forming apparatus with an exposure-light intensity adjusting

The density of a toner in a developing device is detected by a magnetic sensor if the density is lower than a reference value, a toner-empty state is indicated on a control panel. When a copy key is operated in this toner-empty state, the number of copies in the toner-empty state is counted by means of a counter. If the count value is not larger than a preset value, the copying operation is allowed. If the count value exceeds the predetermined value, the copying operation is prohibited.

Image forming apparatus having toner-empty detecting and indicating

Disclosed is a developing device, which develops an electrostatic latent image by applying a toner thereto. The device is provided with an auto-toner adjuster, which detects the toner content of a developing agent, and resupplies the toner in accordance with the detected value, thereby keeping the toner content constantly at a predetermined value. At the shipment from the factory, the developing device is sealed hermetically, storing the developing agent used in setting the toner content by the toner adjuster.

Developing device with toner density adjustment

The invention provides an image density detecting unit for an image formation apparatus, which is made of a transparent optical medium, which has a reflecting plate whose section is substantially a quadric surface, and which has a focusing unit for focusing, by means of the reflecting plate, light incident on the transparent optical medium at a predetermined position inside the transparent optical medium.

Image density detecting unit for image formation apparatus

An electrophotographic copying apparatus comprises a photoconductive drum, a charger for electrically charging the drum, an exposure unit for exposing the drum to form a latent image on the drum which correspond to the pattern of a document, a developer unit for developing the latent image, using one-component toner, a transfer unit for transferring a toner image to a paper sheet and a fixer unit for fixing the toner image. In copying the document pattern, a document density-copy density characteristic, i.e. .gamma. characteristic, is set in accordance with the document density. According to the .gamma. characteristic the amount of exposure and the bias voltage to be applied on the developer unit are varied.

Electrophotographic copying apparatus for effecting a copying operation

A copying machine has a microcomputer which is capable of actuating a plurality of processing components, including an automatic document feeder, a semi-automatic document feeder and a sorter, to continuously perform automatic copying with time sequence. This microcomputer has a random access memory. In the random access memory (RAM) are stored a series of programs for continuous copying specified at a keyboard by a user, that is, copying conditions such as a copying sheet number, modes of enlarged copying, reduced copying and copying of equal size, selection of an outfeed position of the sorter, selection of the automatic document feeder or the semi-automatic document feeder, and changes in paper sizes. The microcomputer controls respective components of the copying machine so as to perform continuous copying in response to the program stored in the RAM.

Growing community of inventors

Kawasaki, Japan

Shouji Takano