摘要:
In an image forming apparatus, the absolute value (.vertline.VBH-VM.vertline.) of the potential difference between a first development bias electric potential (VBH) and an intermediate electric potential (VM) is set to be smaller (.vertline.VBH-VM.vertline.
摘要:
An electrostatic recording apparatus including: an image carrier including an organic photoconductive photoreceptor having an abrasion-resisting outermost periphery; an exposing unit which exposes the image carrier to form an electrostatic latent image thereon; a developing unit which contains a toner and develops the electrostatic latent image with the toner to form a toner image; a transferring unit which transfers the toner image thus formed onto a recording medium; and a fixing unit which fixes the transferred toner image on said recording medium, wherein the toner contained in said developing unit includes an electrically conductive fine powder attached to the surface thereof.
摘要:
In a developing system containing a combination of forward-rotating and a backward-rotating developing rollers, a steady quantity of developing agent should be supplied to the developing rollers for high-quality printed images. This requirement can be satisfied by placing a doctor blade between an intersection point, where a line connecting the central axis of one of the developing rollers and its polarity reversing position meets a line connecting the central axis of the other of the developing rollers and its polarity reversing position, and the developing roller pair. Further, the doctor blade should be located on the upstream side of the developing agent flow relative to the central axes of the backward-rotating developing roller and the forward rotating developing roller with its rightmost side (upstream side) in parallel with the line connecting the central axes of the developing rollers, and the doctor gap (on the side of the developing roller to which the developing agent is supplied) should be greater than a minimum gap (doctor gap) between one end of the doctor blade and the surface of the developing roller to which the developing agent is first supplied.
摘要:
A uniform image is obtained by matching the sliding friction force, the moving speed and the developing agent in a developing region of two developing rollers and an electric characteristic of a photosensitive body used for image development. Two developing rollers rotating in directions opposite to each other are used, the moving direction of the first developing roller being opposite to the moving direction of the photosensitive body, and a circumferential speed ratio of a circumferential speed of the first developing roller to a circumferential speed of the photosensitive body is within a rage of 0.5 to 2.5; and the moving direction of the second developing roller is equal to the moving direction of the photosensitive body, and a circumferential speed ratio of a circumferential speed of the second developing roller to a circumferential speed of the photosensitive body is within a range of 1.5 to 3.5. A ratio of the sliding friction force between a magnetic brush for developing agent and the photosensitive body formed in the first developing roller and the sliding friction force between a magnetic brush for developing agent and the photosensitive body formed in the second developing roller is within a range of 0.9 to 2.1.
摘要:
In an electrostatic both-side printing system, a first image forming unit is provided upstream of an image printing medium when viewed in the transporting direction of the image printing medium, and a second image forming unit is provided downstream of the image printing medium. A medium transporting path for transporting the image printing medium is formed between the first and the second image forming units. A first transferring unit, located facing the first image forming unit with the medium transporting path intervening therebetween, for applying no charge onto the rear side of the image printing medium, which does not face the first image forming unit. A second transferring unit being located facing the second image forming unit with the image printing medium with the medium transporting path intervening therebetween, in a state that the second transferring unit is apart from a first toner image formed on the image printing medium by the first image forming unit. In the both-side printing system thus constructed, the first and the second image forming units, and the first and the second transferring units cooperate to form first and second toner images on both sides of the image printing medium, the first and the second toner images being opposite in polarity.
摘要:
In an image forming apparatus forming an electrostatic latent image on a surface of a photosensitive body by exposing the charged photosensitive body, developing the latent image using a toner to form a toner image, transferring the toner image to a image holding body, and erasing the remaining charge on the surface of the photosensitive body after completion of the transferring, the photosensitive body is formed of a base material consisting of As.sub.2 Se.sub.3 or a-Si, and wherein the wavelength .lambda..sub.0 of the writing light used for the exposure is limited to a wavelength not larger than 780 nm, the wavelength .lambda..sub.1 of charge erasing light used for the charge erasing is limited to a wavelength smaller than 680 nm, and the time T.sub.1 from completion of the exposure to initiation of the development is limited within the range of 70 milliseconds to 300 milliseconds.
摘要:
In a method for electrophotography comprising an electrostatic transfer process, after an electrostatic latent image formed on a surface of a photoconductive and photosensitive member has been developed with toner, the surface of the photoconductive and photosensitive member and a toner image are charged at the same polarity as the electrostatic latent image and thereafter the toner image is electrostatically transferred onto a recording medium to obtain a record.
摘要:
Apparatus for monitoring the concentration of toner in a mass of developer mix including the toner and carrier particles, having a sampling cylinder inside which the developer mix flows. An accumulating cylinder is disposed over the sampling cylinder. At the upper end part of the accumulating cylinder, a guide plate is disposed by which the developer mix is supplied to the accumulating cylinder. At the lower end part of the accumulating cylinder, a developer mix supplying roll is disposed by which the developer mix at a fixed flow rate is supplied to the upper end opening of the sampling cylinder. On the other hand, at the lower end opening of the sampling cylinder, there is disposed a magnet roll by which the developer mix at a fixed flow rate is discharged from inside the sampling cylinder. The flow rate of the developer mix to be supplied to the sampling cylinder is set to be greater than the flow rate of the developer mix to be discharged, so that part of the developer mix supplied towards the sampling cylinder overflows from the upper edge of the sampling cylinder. Therefore, the developer mix inside the sampling cylinder flows in a stable state. A detecting coil is disposed on the outer periphery of the sampling cylinder, and detects the toner concentration of the developer mix in the form of an inductance.
摘要:
A light conductive photosensitive member belt is charged uniformly by use of a charger and an electric charge latent image having three values is formed by means of a laser beam light L.sub.1. After then, after the passage of time t.sub.1, a yellow developing device is used to develop yellow and, after the passage of time t.sub.2, a magenta developing device is used to develop magenta. Next, the photosensitive member belt is recharged by a recharger and another latent image having three values is formed by means of a laser beam light L.sub.2. After then, after the passage of time t.sub.1, a cyan developing device is used to develop cyan and, after the passage of time t.sub.2, a black developing device is used to develop black. Then, these four color toner images are transferred to recording paper.
摘要:
A cleaning device for a dry electrophotographic device includes a cleaning brush brought into resilient contact with an object to be cleaned such as a photosensitive drum. A cleaning roll rotates while constantly being brought into contact with the cleaning brush and a cleaning blade is pressed against the cleaning roll to clean the cleaning roll. A rotation direction switching mechanism switches the rotation direction of the cleaning brush such that the rotation direction of the cleaning brush when cleaning the object, for example, during the formation of an image, is different from that when the brush is not cleaning the object.