Abstract: A developer conveying device includes a housing, a developer conveyance path and a conveying member. The developer conveyance path extends between the pair of wall portions of the housing. The conveying member conveys developer from one wall portion toward the other. The conveying member includes a spiral member, shaft portions, a rib member, a supporting member and a projecting portion. The spiral member is formed by connecting spiral pieces in a conveying direction of the developer and includes a hollow interior formed by the connected spiral pieces. The rib member extends in the conveying direction and bridges adjacent ones of the spiral pieces of the spiral member. The supporting member connects an end part of the rib member in the conveying direction and the shaft portion. The projecting portion projects from the end part of the rib member more toward the wall portion than the supporting member.

Abstract: An image forming apparatus includes a waste toner box, a base, a detection sensor, a counter and a controller. The waste toner box collects toner not transferred to a sheet but remaining on a surface of a photoreceptor. The base is for placing the waste toner box thereon, and a position of the base changes with a weight of the waste toner box placed thereon. The detection sensor detects the position of the base to detect an amount of toner in the waste toner box placed on the base. The counter counts the number of sheets with images formed thereon. The controller determines whether or not to continue image formation on a sheet on a basis of a signal from the detection sensor and the counter.

Abstract: A transfer device includes a transfer belt, a transfer roller and a tension roller over which the transfer belt is passed in a tensioned condition and which is made to be in an electrically floated state; it also includes a guide member that is installed in the vicinity of the tension roller. A control section, in transfer processing, controls a first switch so that the guide member is in a grounded state while controlling a second switch so that an electric current being caused to flow to the transfer roller becomes a first electric current; and in cleaning processing, controls the first switch so that the guide member is in an electrically floated state while controlling the second switch so that an electric current being caused to flow to the transfer roller becomes a second electric current.

Abstract: A transfer device includes an intermediate transfer belt, and a plurality of intermediate transfer rollers. A most upstream side intermediate transfer roller which is located most upstream in a moving direction of the intermediate transfer belt has a rotational axis arranged downstream from a rotational axis of a most upstream side photoreceptor drum which is located most upstream in the moving direction of the intermediate transfer belt when the most upstream side intermediate transfer roller is in its pressing position, while a most downstream side intermediate transfer roller which is located most downstream in the moving direction of the intermediate transfer belt has a rotational axis arranged upstream from a rotational axis of a most downstream side photoreceptor drum which is located most downstream in the moving direction of the intermediate transfer belt when the most downstream side intermediate transfer roller is in its pressing position.

Abstract: An image forming apparatus includes a transfer belt unit which has an intermediate transfer belt for supporting toner images and primary transfer rollers for pressing the intermediate transfer belt against corresponding photoreceptor drums and moves the intermediate transfer belt along the surface of each photoreceptor drum to transfer the toner images to the intermediate transfer belt. The intermediate transfer belt is formed so as to be 30 ?m to 50 ?m in average thickness, each primary transfer roller is arranged at a position, along the moving direction of the intermediate transfer belt, which is deviated downstream with respect to the moving direction from the position where the intermediate transfer belt is in contact with the photoreceptor and which is projected toward the photoreceptor drum side so as to press the intermediate transfer belt against photoreceptor with a nip pressure ranging from 10 gf/cm2 to 40 gf/cm2.

Abstract: In a metal halide lamp having a rated lamp wattage of greater than or equal to 450 W, which includes: a translucent ceramic arc tube enclosure including: a main tube inside which a discharge space is formed; and two narrow tubes having smaller diameter than the main tube, each connected to either end of the main tube; two electrodes; and a metal halide provided inside the arc tube enclosure, in which one of the two electrodes is disposed so that it protrudes inside the main tube from inside of one of the two narrow tubes, and the other one of the two electrodes is disposed so that it protrudes inside the main tube from the other one of the two narrow tubes, and when the rated lamp wattage is denoted by W (watt), an inside diameter of the main tube by D (mm), an electrode protruding length which is the distance from boundary between the main tube and the narrow tubes to an end of the electrode by L (mm), and the distance between ends of the two electrodes by E (mm), a bulb wall loading G (watt/cm2) represented

Abstract: For an electrostatic latent image formed on an image carrier (31b), besides an operation forming an “image forming electrostatic latent image” used to form the primary image, an operation is executed that forms an “electrostatic latent image for removing developer” for removing developer that resides on a developer supply member (53a) for a predetermined time period onto the image carrier (31b). Thus, developer is nearly eliminated from residing on this developer supply member (53a) in an overcharged state for a long period of time, and generation of a fogged image is avoided as much as possible.

Abstract: An ion generating device provided in an image forming apparatus of the present invention as a charging device for charging before a first transfer, a charging device for charging before a second transfer, or a charge device for charging an electrostatic latent image is arranged such that a discharge electrode can move with respect to a dielectric material and the relative positions of the discharge electrode and the dielectric material can be changed. This makes it possible to provide: a long-life ion generating device whose life has been extended by making effective use of a dielectric material; and an image forming apparatus including the ion generating device.

Abstract: A radiographic image conversion panel containing a substrate having thereon a phosphor layer formed by a vapor-accumulating method, wherein the phosphor layer has a thickness distribution of not more than ±20%, the thickness distribution being defined by the formula: ((Dmax?Dmin)/(Dmax+Dmin))×100, provided that Dmax is a maximum thickness of the phosphor layer; and Dmin is a minimum thickness of the phosphor layer.

Abstract: A fixing device includes a fixing roller for fixing a toner image transferred onto a sheet and conveying the sheet along a conveyance path, and a separating mechanism for separating the sheet from the fixing roller. The separating mechanism includes a claw member having a tip portion in contact with the outer circumferential surface of the fixing roller to separate the sheet from the fixing roller, a holder member for holding the claw member, and a rotary member rotatably held in the holder member downstream of the tip portion relative to the conveyance path and adapted to guide the sheet separated from the fixing roller to a downstream side along the conveyance path while being rotated. The holder member has a guiding portion for guiding the sheet to the rotary member on the conveyance path between the tip portion of the claw member and the rotary member.

Abstract: A transfer unit includes: an intermediate transfer belt that (i) holds a toner image that has been transferred from a photoreceptor drum and (ii) moves a surface holding the toner image; and a secondary transfer belt that comes into contact with the intermediate transfer belt. The transfer unit (i) transfers the toner image from the intermediate transfer belt to a sheet conveyed to the secondary transfer part and (ii) includes a cleaning unit that removes and collects toner from the surface of the intermediate transfer belt. The transfer unit also includes a power source for sequentially applying, to the secondary transfer belt, (i) a first voltage for generating an electric field that transfers normally-charged toner from the secondary transfer belt to the intermediate transfer belt and (ii) a second voltage for generating an electric field that transfers oppositely-charged toner from the secondary transfer belt to the intermediate transfer belt.

Abstract: To provide a ceramic metal halide lamp having a rated lamp wattage of not less than 450 W, which will not cause flicker due to instable arc during operating of the lamp and early blacking of an arc tube.

Abstract: A fixing device is provided with a fixing roller for fixing a toner image transferred on a sheet to the sheet, and a separating mechanism for separating the sheet from the fixing roller. The separating mechanism includes a claw member having a tip portion held in contact with the outer circumferential surface of the fixing roller for separating the sheet from the fixing roller, a supporting member pivotably supporting the claw member, and a biasing member for biasing the claw member toward the outer circumferential surface of the fixing roller so that the tip portion of the claw member presses the fixing roller.

Abstract: An ion generating device provided in an image forming apparatus of the present invention as a charging device for charging before a first transfer, a charging device for charging before a second transfer, or a charge device for charging an electrostatic latent image is arranged such that a discharge electrode can move with respect to a dielectric material and the relative positions of the discharge electrode and the dielectric material can be changed. This makes it possible to provide: a long-life ion generating device whose life has been extended by making effective use of a dielectric material; and an image forming apparatus including the ion generating device.

Abstract: A discharge unit is disposed downstream of a principal transport path of a compound machine, and a shifter function is provided in this discharge unit. By shifting the paper passage position relative to a photosensitive drum when printing the front side and the paper passage position relative to the photosensitive drum when printing the back side, the region in which the surface electric potential of the photosensitive drum increases is diminished, and the region in which photographic fog is generated is made smaller. Thus, when printing the second and subsequent sheets, even when a slight amount of displacement of the transport position of the recording paper occurs, it is possible to suppress that recording paper making contact in the photographic fog region on the photosensitive drum, and defective printing can be prevented.

Abstract: In an image forming apparatus that uses a charging unit to charge a photosensitive drum, forms an electrostatic latent image by carrying out image exposure according to image information, and transfers to a paper the electrostatic latent image by developing the electrostatic latent image into a visible image using a developer so that the image information is presented, an exhaust duct 33 for exhausting air that contains ozone produced within a drum unit 30, which includes a photosensitive drum 3 and a charging unit 5, and a duct 32 for taking in air, which draws in fresh air, are provided within the drum unit 30 so that ventilation of the drum unit 30 can be carried out with excellent efficiency.

Abstract: A color image forming apparatus 1 includes: a multiple number of process printing units 20, each having an photoreceptor drum 21 for bearing a developer image formed with a toner corresponding to a different color of color-separated image information; a transfer belt 31 to which a multiple number of developer images are comprised in layers; and a transfer roller 36 for transferring the developer images that have been comprised in layers on transfer belt 31, all at once, to recording paper, wherein the multiple number of process printing units 20 are arranged along transfer belt 31, and is characterized in that among the developer images to be transferred from the photoreceptor drums 21 of multiple image forming units 20 onto transfer belt 31, the toner for the developer image of the color to be transferred first is specified to produce a base-layer of the color images of information.

Abstract: A cleaning blade for removing residual toner left on the surface of an intermediate transfer belt after the second transfer is supported integrally with movement of a tension roller. In the case where the tension roller moves to make a tension of the intermediate transfer belt constant, then, following this, the cleaning blade moves. Thus, the contact state of the cleaning blade with respect to the surface of the intermediate transfer belt is kept constant, and thus cleaning of the intermediate transfer belt can be performed stably.

Abstract: A radio graphic image conversion panel containing a substrate having thereon a phosphor layer formed by a vapor-accumulating method, wherein the phosphor layer has a thickness distribution of not more than ±20%, the thickness distribution being defined by the formula: ((Dmax?Dmin)/(Dmax+Dmin))×100, provided that Dmax is a maximum thickness of the phosphor layer; and Dmin is a minimum thickness of the phosphor layer.

Abstract: A color image forming apparatus includes: a multiple number of process printing units, each having an photoreceptor drum for supporting a developer image formed with a developer corresponding to each color of color-separated image information; a transfer belt to which the developer images formed on the photoreceptor drums are transferred; and a transfer roller for transferring the transferred developer image to recording paper, and is constructed so that the transfer belt is formed of a material which makes it possible for the transfer belt to attenuate the voltage charged thereon by 1,000 V or greater while it moves from a position where secondary transfer is performed to a position where the initial primary transfer is performed.