Abstract: The present invention provides an image forming apparatus having an electrophotographic image forming means for fixing a toner image formed on a sheet to the sheet by heating the toner image, wherein an interval between the sheets when the sheets are continuously sent to the image forming means to form images on both surfaces of plural sheets is selected to become smaller than an interval between the sheets when the sheets are continuously sent to the image forming means to form images on one surfaces of the plural sheets.

Abstract: A toner content control device for an electrophotographic apparatus of the type using a toner and carrier mixture. The control device determines an amount of toner replenishment on the basis of a difference between the toner content of the developer and a reference value, while correcting the reference value in accordance with the condition of a reference pattern formed on a photoconductive element. Although the control device includes a toner content sensor and a pattern density sensor, it omits conventional means for adjusting the toner content sensor. The control device is therefore capable of controlling image density stably with an inexpensive configuration.

Abstract: A developing apparatus has a developer support 2 to which a developing bias VB with an AC component VAC superimposed on a DC component is applied for visualizing a latent image on a latent image support 1 in a dual component developer G supported on the developer support 2. It includes a use history estimation 5 for estimating a use history of the developer G or a use history detection device 6 for detecting a use history of the developer G and a developing bias power supply 3 provided with a peak-to-peak voltage changing device 4 for changing a peak-to-peak voltage Vp-p of the AC component VAC based on information from the use history estimation device 5 or the use history detection means 6.

Abstract: A electronic printing apparatus includes memory for storing a digitized image. A receiver is transported to an image forming position, the receiver including field-driven particles in a matrix that can change reflective density in response to an applied electric field. The apparatus further includes an array of electrodes for selectively applying electric fields at the image forming position across the receiver; a heater for heating the receiver to increase the temperature of the matrix so as to increase the mobility of the field-driven particles in the matrix; and electronic control circuitry coupled to the array for selectively applying voltages to the array so that fields are applied at the image forming position to the heated field-driven particles at particular locations on the receiver corresponding to pixels in response to the stored image whereby the electrode produces an image in the receiver corresponding to the stored image in the receiver.

Abstract: An image forming apparatus for conveying recording material. The image forming apparatus includes an image bearing member for bearing a toner image, a recording material convey belt for bearing and conveying a recording material, a roller for supporting the recording material convey belt and having an insulation layer, and an electricity removal device for removing electricity from the insulation layer. The toner image on the image bearing member is electrostatically transferred onto the recording material borne by the recording material convey belt, and the roller supports the recording material convey belt at a separation position where the recording material is separated from the recording material convey belt.

Abstract: When the upper case of the developing device is pushed from above, the upper case may be deformed producing a negatively activated pressure corresponding to the deformed volume of the case, thereby dispersing toner along with the air. When the developing device is mounted to or dismounted from the color image forming apparatus, the dispersed toner may fall out of the developing device. To prevent the toner from falling out of the developing device, the toner carrier and the limiting member for limiting the toner layer thickness are held in the developer case and a falling toner receiver is formed which is recessed in the developer case in the longitudinal and widthwise directions of the toner carrier and the limiting member for limiting the toner layer thickness. The falling toner is collected in the receiver, preventing the device from being contaminated with the falling toner and facilitating the cleaning of the device.

Abstract: A single pass color printer employs a band drive to move media sheets through plural developer stations. The band drive also provides motive power to drive, in common (via frictional engagement with their respective peripheries), all of the organic photoconductor (OPC) rollers that are present in plural developer stations that are arrayed along the media movement path. The use of the common band drive assures that the surface speeds of the OPC drums and media sheets are synchronized at their respective points of contact, thus eliminating much of the station to station variations due to differences in diameters and runout of the plural OPC rollers.

Abstract: An ink jet type recording head is capable of preventing the occurrence of cracks in a portion close to the circumferential wall of the pressure generating chamber of the piezoelectric active section so as to enhance the durability of the recording head.

Abstract: A multi-beam scanning system has a beam control using an Electrostatic Voltage Sensor or an Image Density Sensor on the Organic Photoconductor. The laser beams can be attuned according to the voltage or density results. This results in a more reliable system as compared to the use of one or more photodetectors.

Abstract: The present invention provides an image forming apparatus including a first image forming unit for forming an image on a recording material at a first image forming position, a second image forming unit for forming an image on the recording material at a second image forming position different from the first image forming position, a light permeable recording material bearing member for bearing the recording material and for conveying the recording material to the first and second positions, a position detecting unit for detecting a position of a test pattern formed on the recording material bearing member by the first and second image forming unit, and a light reflecting member adapted to reflect light passed through the recording material bearing member onto the position detecting unit and shiftable to a position where the light is not reflected onto the position detecting unit.

Abstract: An electrophotography developing apparatus has been developed which can protect a developer holder and a layer thickness control member from damage. The device also prevents internal scattering of the developer while preventing a surplus supply of the developer to both ends on the peripheral surface of the developer holder. The unique advantages of the invention are derived through the utilization of sealing members having different elastic properties, which assume both bulk removal of excess developer while providing the needed uniform developer thickness. Another embodiment of the invention has the width of the layer thickness control member in a longitudinal direction set wider than the width of the developer holder in a longitudinal direction, and both side edges of the layer thickness control member are positioned outside both side edges of the developer holder.

Abstract: A developer cartridge is used with an image forming apparatus. The developer cartridge has a groove which formed in a longitudinal end surface of thereof and extends in an insertion direction of the cylinder. A strip-shaped projection formed in the image forming apparatus projects extends in the insertion direction. When the developer cartridge is fully inserted into the image forming apparatus, the groove receives the projection so that the projection is at a predetermined position relative to the developer cartridge. Two first walls define the groove which is progressively wide as the circumference is approached. A second wall rises from the longitudinal end surface of the developer cartridge and is continuous with one of the two first opposed walls. The second wall smoothly guides the projection into the groove.

Abstract: An image forming apparatus includes: a first image carrier for carrying a toner image formed by an toner image forming device; a second image carrier for carrying thereon the toner image transferred from the first image carrier, and for transferring a transfer sheet thereon; a first transfer device for transferring the toner image carried on the first image carrier onto the second image carrier or a front side of the transfer sheet; a second transfer device for transferring the toner image carried on the second image carrier onto a back side of the transfer sheet; a fixing device for fixing the toner image transferred on the transfer sheet, wherein the second image carrier has a curvature portion at an edge thereof facing the fixing device; and a conveyance section provided between the curvature portion and the fixing device, having a claw member provided adjacent to the curvature portion for lifting a leading edge of the transfer sheet conveyed along the curvature portion.

Abstract: An ink jet printing apparatus responsive to an input digital image for producing a halftone image on a receiver, such as a lithographic plate, having halftone dots with each halftone dot being formed by one or more microdots in a screen dot of selectable areas, including an adjustable printhead for delivering different volumes of ink droplets which, when they contact the receiver, forming microdots of different areas according to the selected screen dot size. The apparatus delivers ink to the printhead and is responsive to a selected screen dot size and the digital image to control the printhead to form ink droplets of different volumes to produce a halftone image on the receiver.

Abstract: To provide a print head unit and device and a method for evaluation of the print head unit without performing a printing operation. A current probe 21 detects a head ground current, which corresponds to a driving circuit output current. A current-voltage converter 22 converts the head ground current to a voltage level. Then, an integrating device integrates the voltage level to a waveform which corresponds to the head ground current. By comparing the produced waveform with a proper waveform one can determine, whether the print head unit is operational.

Abstract: An electrophotographic printing machine has a photoreceptive member. The photoreceptive member is charged and then exposed with a light image representation to form a latent image. An electric field, less than that required to re-charge the photoreceptive member, is applied to the latent image to increase the rate of discharge of the exposed portions of the latent image. The latent image is then developed.

Abstract: A printer or copier which operates by transfer printing has a fixing roller for affixing toner to the recording medium. A release agent, or parting oil, is applied to the roller by a dosing tube having openings through which the release agent flows to a wick. An application element is moved over the roller between the wick and the roller for cleaning and application of the release agent. The wick is held in guide elements and the lower guide element has a duct for collecting excess release agent and applying it to the application element.

Abstract: A copier includes a transfer charger for electrostatically transferring a toner image which is formed on a surface of a photoelectric drum to a sheet and a separation charger for separating the sheet with a toner image transferred thereto from the drum surface. A transfer guide is provided on a conveying path upstream of the transfer charger to guide the sheet toward a transfer point provided relative to the photosensitive drum. A separation supporter for supporting the sheet is provided above the separation charger.

Abstract: When a surface sheet manufacture mode is selected, a CPU calculates a size of a back sheet portion of a surface sheet, on the basis of a sheet thickness detected by a sheet thickness detect portion, a consumed toner amount calculated by an estimate circuit and the number of transfer materials counted. After the predetermined number of imaged transfer materials are outputted, a transfer material having a size accommodating with the calculated size of the back sheet portion, whereby information for determining the size of back sheet portion of the surface sheet can be inputted correctly.

Abstract: A developing apparatus including a developing frame, a developing roller disposed at an opening portion of the developing frame and adapted for bearing a developing agent, a first seal member for closing a gap between the developing frame and the developing roller along an entire length of the gap in a circumferential direction of the developing roller to prevent leakage of developing agent, and a second seal member contacted with outer end face of the first seal member, wherein the second seal member is only provided downstream of a developing zone at which electrostatic latent images are developed, with respect to a rotational direction of said developing roller.