Abstract: An apparatus for and a method of reliably detecting a very small dotted image area. A detecting area including a predetermined number of pixels including a target pixel is set. It is judged whether or not the detecting area belongs to a dotted image area on the basis of the number of edge pixels in the detecting area. Consequently, it is possible to detect edges peculiar to the dotted image area on the basis of a leading edge portion or a trailing edge portion of the density, to detect the very small dotted image area on the basis of the number of edge pixels.

Abstract: A toner cartridge includes a container body having a toner transport passage, and a toner transporter disposed in the toner transport passage for transporting toner from one end portion toward the other end portion of the toner transport passage while agitating the toner along the toner transport passage. The container body has a toner discharge port provided at the other end portion of the toner transport passage, and a recycle toner entry port provided at the one end portion of the toner transport passage. When the toner cartridge is mounted at a predetermined position, the toner discharge port is positioned opposite a toner feed port provided in a developing device, while the recycle toner entry port is positioned opposite a recycle toner drop port provided in a recycle toner carrier.

Abstract: A document original simulator including first tone simulation portion having substantially the same reflectance as a white original sheet and a second tone simulation portion having a lower reflectance than the first tone simulation portion. When an image fogging detecting operation is to be performed with the use of the document original simulator, it is checked whether or not the amount of light reflected from the first tone simulation portion when the first tone simulation portion is illuminated with light is smaller than the amount of light reflected from the white original sheet placed on a document original presenting section when the white original sheet is illuminated with light.

Abstract: A facsimile machine provided with a data processing device for executing data processing in communications mode in accordance with a command entered from a communications apparatus having a capability of transmitting and receiving communications data. The facsimile machine includes a mode select device for switching itself from ordinary facsimile mode for image data transmission and reception to communications mode for communications data transmission and reception in accordance with an operator input; an operation judgment device for judging whether the data processing device has accomplished a printing job, in which data received from the communications apparatus is printed on paper, after the mode select device has switched the facsimile machine to communications mode; and a mode reset device for resetting the facsimile machine to facsimile mode when completion of the printing job has been confirmed by the operation judgment device.

Abstract: An electromagnetic clutch includes a field member having a hollow in a center thereof and carrying a field coil in the form of a ring, a shaft rotatably placed in the hollow of the field member, a rotor member fixedly attached on the shaft, the rotor member being arranged on one side of the field member, a driving member rotatably mounted on the shaft, the driving member being arranged on one side of the rotor member, and an armature member attached to the driving member, the armature member being arranged between the rotor member and the driving member and bendable toward the rotor member.

Abstract: A document feeder to be mounted atop an image reading device having a stationary optical system disposed under a contact glass. The document feeder includes a document original plate for holding thereon document originals, a document original feeding mechanism for feeding a document original from the document original plate onto a contact glass, a document original transporting mechanism for transporting the document original fed by the document original feeding mechanism along the upper surface of the contact glass, a document original discharging mechanism for discharging the document original transported by the document original transporting mechanism, and a document original discharge plate for receiving the document original discharged by the document original discharging mechanism. The document original feeding mechanism, the document original transporting mechanism and the document original discharging mechanism are integrally supported in a unit body to constitute a single unit.

Abstract: The developing process of this invention comprises supplying a charged toner to a development roller disposed against a photosensitive drum, forming a thin layer of the charged toner on the development roller by a blade press-contacted with the development roller, and contacting this thin layer of the charged toner on the surface of the photosensitive drum on which an electrostatic latent image is formed. The process further comprises using a non-magnetic toner which has a circularity degree of more than 0.94 and which has a falling amount of at least 10 g/5 minutes as measured by a tester for measuring the amount of falling. By using such a toner, it is possible to prevent the collection of the toner on the bottom of a development housing which includes various members for practicing the above process, and it is also possible to prevent the rising of a driving torque of the rollers.

Abstract: A developing device having a container including a pair of side walls disposed with spacing, an entry port and a delivery port defined between the side walls, and a main wall extending between the entry port and the delivery port. A rotating shaft is rotatably mounted between the pair of side walls of the container, and agitator/conveyor means is mounted on the rotating shaft. A blind hole circular in cross section is formed at an inner surface of one of the side walls, and one end portion of the rotating shaft is rotatably inserted into the blind hole. At least one discharge groove is formed at an outer peripheral surface of the one end portion of the rotating shaft. The agitator/conveyor means is composed of a flexible agitating/conveying member extending from the rotating shaft in a radial direction of the rotating shaft.

Abstract: The present invention provides a novel stilbene derivative represented by the general formula (1): ##STR1## wherein R.sup.1 and R.sup.3 represent an alkyl group, an aryl group, an aralkyl group or an alkoxy group which are optionally substituted; and R.sup.2 and R.sup.4 represent a hydrogen atom, an alkyl group or an alkoxy group which are optionally substituted, provided that when the substitution position of R.sup.2 and R.sup.4 is the 4-(para) position, R.sup.2 and R.sup.4 are hydrogen atoms, a method for producing the same and use thereof. The above stilbene derivative (1) is useful as an electric charge transferring material, particularly hole transferring material.

Abstract: A nitro group-containing naphthoquinone derivative represented by the following general formula: ##STR1## wherein R is a monovalent hydrocarbon group having a nitro group, and a ring A may be substituted with a substituent.This compound is a novel substance and is useful as an electron-transporting agent for an electrophotosensitive material. The electrophotosensitive material using the electron-transporting agent is highly sensitive, exhibits favorable repetitive properties, and makes it possible to favorably form images for extended periods of time.

Abstract: An automatic document feeder conveys an original along a conveying path to an original reading section in an image processor. First and second registration rollers for abutting the conveyed original against their contact portions, and a guide plate for guiding the conveyance of the original to the registration rollers are arranged in the conveying path. The first registration roller includes a plurality of reversing rollers made of rubber for reversing the original along a reversing path, and the reversing rollers are arranged a predetermined distance away from each other along an axis of their supporting shaft. A side edge in the direction of conveyance of the guide plate is in such a comb shape that projections and non-projections are alternatively formed. Each of the projections is opposite to a region between the adjacent reversing rollers, and extends toward the downstream side of the contact portions in the direction of conveyance.

Abstract: The present invention provides an electrophotosensitive material comprising a photosensitive layer containing a m-phenylenediamine compound represented by the general formula (1): ##STR1## wherein R.sup.1A and R.sup.1B are the same or different and indicate an alkyl group; and R.sup.1C, R.sup.1D, R.sup.1E and R.sup.1F are the same or different and indicate a hydrogen atom or an alkyl group, which has high sensitivity and issuperior in stability to strong light, durability and heat resistance, and an image forming method capable of realizing more higher speed and more larger energy saving than the prior art.

Abstract: An apparatus for encrypted communication in which transmission data is encrypted based upon a cipher key and is transmitted. The received encrypted data is decrypted based upon a cipher key. A cipher key checker checks for agreement of the cipher keys by decoding the decrypted received data. The cipher key checker decodes the decrypted data in a unit of a preselected number of lines and determines whether the data are properly decoded or not.

Abstract: A device for recovering toner in an image-forming machine includes a cleaning mechanism for removing the toner that remains on an image carrier, a toner conveyer mechanism for conveying the toner removed by said cleaning mechanism, and a toner recovery container for containing the toner conveyed by said toner conveyer mechanism. The toner conveyer mechanism includes a toner conveying pipe connected at its one end to said cleaning mechanism and having, at its other end, a toner discharge port that faces a toner reception port formed in said toner recovery container, a toner conveying member in the form of a coil arranged in said toner conveying pipe and is coupled at its one end to a rotary member, and a toner-scraping member mounted on the other end of said toner conveying member and rotates together with said toner conveying member.

Abstract: A photosensitive drum unit for an image forming device includes a tubular member having two openings at the opposite ends thereof, two flange members pressed into the openings of the tubular member, and an electroconductive ground plate attached to one or both of the flange members. The ground plate is provided with a plurality of projections formed integrally with the ground plate. The projections engage with the tubular member in order to create an electrical connection between the photosensitive drum and the body of the image forming device.

Abstract: A sheet transportation device for use in an image forming apparatus is provided which has self-diagnosis and self-repair functions. The sheet transportation device has a sheet transportation system including a plurality of units (8). A control sequence for a sheet transportation operation is applied from a system body (10) to the respective units (8). The units (8) each execute the control sequence to perform the sheet transportation operation. The units (8) are each constructed so as to perform an autonomous operation. This construction allows the respective units to autonomously perform self-diagnosis and repair operations. The fault diagnosis and repair operations are performed in parallel to the sheet transportation control. Therefore, the sheet transportation device can flexibly adapt itself to an external influence such as a change in the use environment and a malfunction due to a time-related change such as the aging of components thereof.

Abstract: This is invention is directed to a shaft coupling for coupling a first shaft and a second shaft. The shaft coupling includes an outer ring for encasing one end of the first shaft and one end of the second shaft; a first pin provided in the outer ring and the first pin extending in a first direction; and a second pin provided in the outer ring and the second pin extending in a second direction substantially orthogonal to the first direction; wherein the first shaft and the first pin are so set such that the end of the first shaft is movable along the first pin and the second shaft and the second pin are so set that the end of the second shaft is displaceable along the second pin.

Abstract: The present invention provides a naphthoquinone derivative represented by the general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are as defined in the specification. An electrophotosensitive material containing this naphthoquinone derivative as an electron transferring material has high sensitivity.

Abstract: When a calling facsimile receives a second control signal, the calling facsimile compares second information relating to the capabilities of a called facsimile and first information relating to the capabilities of the called facsimile which is stored in storage means on the basis of the second control signal. When the capabilities of the called facsimile are changed, the first information relating to the capabilities of the called facsimile which is stored in the storage means is updated, and a third control signal composed of a tone signal indicating that a facsimile message should be sent to the called facsimile is sent out to the called facsimile.

Abstract: A toner replenishing device for an image forming machine has a hopper housing with a toner agitating passageway and a toner carrying passageway, a toner agitator disposed in the toner agitating passageway for agitating recovered toner and fresh toner supplied to the toner agitating passageway and lifting them to the toner carrying passageway, and a toner carrier disposed in the toner carrying passageway for carrying the recovered toner and the fresh toner agitated and lifted by the toner agitator. The toner agitator has a first paddle disposed in a first end part of the toner agitating passageway, and a second paddle disposed on the other end part side of the toner agitating passageway and adjacent to the first paddle. The first paddle has the function of sending the toner to the other end part side of the toner agitating passageway, while the second paddle has the function of sending the toner to the first end part side of the toner agitating passageway.