摘要:
A magnetic toner includes at least binding resin (for instance, a styrene-acryl resin) and magnetic powder (for instance, Mn--Zn ferrite or Ni--Zn ferrite) having a saturation magnetization of at least 50 emu/g and a coercive force as measured under the magnetic field of 10 kOe not exceeding 50 Oe. An image formed by using this magnetic toner has high quality and is free of tailing.
摘要:
A developer for developing an electrostatic latent image by a developing method of a type in which residual toner particles on an image-bearing member are recovered therefrom and reused for developing the electrostatic latent image, which comprises a magnetic toner and a magnetic carrier. The magnetic toner comprises a binder resin having a number average molecular weight of 2,000-100,000, a weight average molecular weight of 5,000-500,000, and a melt viscosity of 10.sup.5 P or less at 120.degree. C., a release agent having a softening point of 160.degree. C. or lower; and a magnetic powder. The magnetic toner particle is externally added on a surface thereof or internally added thereto with a surface treating agent comprising a fine powder of at least one metal salt of stearic acid, a fine powder of at least one inorganic oxide and an optional resin powder.
摘要:
In an image forming method for developing an electrostatic latent image on an image bearing member by using a two-component magnetic developer includes the steps of supporting and conveying a magnetic developer directly on the surface of a permanent magnet with a plurality of magnetic poles provided on the surface and performing both the removal of the residual toner remaining on the surface of the image-bearing member and the development of the electrostatic latent image while rubbing said surface with said magnetic brush. The magnetic carriers in the magnetic developer have average particle sizes of 5 to 20 .mu.m and opposite to toner in polarity of charge, the magnetization .sigma..sub.1000 in a magnetic field of 1000 Oe is 50 emu/g or less. Nonspherical magnetic toner or non-magnetic toner made by a polymerization process and magnetic carriers may be used.
摘要:
An image forming method for developing an electrostatic latent image on a moving image-bearing member with a magnetic developer and for removing the residual toner after transfer of a developed toner image onto a transfer member is described. The method includes providing a rotatable, cylindrical permanent magnet having a plurality of magnetic poles on the surface for supporting and conveying the magnetic developer directly on the magnet surface; forming an electrostatic latent image into a toner image by attracting and conveying a magnetic developer including a nonspherical magnetic toner obtained by a polymerization or a nonspherical magnetic or non-magnetic toner obtained by a polymerization and magnetic carriers; and removing the residual toner remaining on the image-bearing member after transferring this toner image by a cleaning blade. The method also includes a surface magnetic flux density ranging from 50 to 1200 G, and a value of h, defined as .pi.D.multidot.Vp/(M.multidot.Vm), of 2 or less wherein Vp (mm/s) is the moving speed of the image-bearer, and D (mm), M, and Vm (mm/s) are the outer diameter, the number of magnetic poles, and the peripheral speed of the permanent magnet, respectively.
摘要:
An image forming method for developing an electrostatic latent image on an image-bearing member that moves bearing electrostatic latent images formed of a two-component magnetic developer is described. The method includes the steps of providing a rotatable cylinder for supporting and conveying said magnetic developer, the cylinder including a permanent magnet with a plurality of magnetic poles provided on the surface. Magnetic carriers in the magnetic developer are attracted and conveyed on the surface of the permanent magnet, the magnetic carriers having an average particle size of 5 to 20 .mu.m and opposite to toner in polarity of charge. A carrier particle magnetization .sigma..sub.1000 in a magnetic field of 1000 Oe so as to amount to 50 emu/g or less is also used. The method also includes a surface magnetic flux density ranging from 50 to 1200 G, and a value of h, defined as .pi.D.multidot.Vp/(M.multidot.Vm), of 2 or less wherein Vp (mm/s) is the moving speed of the image-bearer, and D (mm), M, and Vm (mm/s) are the outer diameter, the number of magnetic poles, and peripheral speed of the permanent magnet, respectively.
摘要:
An image forming method for operating a moving image-bearing member bearing an electrostatic latent image and a plurality of developing units disposed near the image-bearing member and being selectively operable is described. The color image forming method develops the electrostatic latent image by using a magnetic developer brush formed on the surface of a developer support and conveyance means, and includes the steps of: providing a rotating cylinder for supporting and conveying the magnetic developer, the cylinder including a permanent magnet with a plurality of magnetic poles on the cylinder surface; supplying a magnetic developer containing non-magnetic color toner for color image formation; attracting and conveying a layer of magnetic developer having a smaller thickness than the gap between the image-bearing member and the developer support and conveyance cylinder on the cylinder surface; and applying in the developing region an alternate electric field with an AC bias superimposed on a DC bias between the image-bearing member and the magnetic developer for the developing of an electrostatic latent image on the image-bearing member. The method also includes a surface magnetic flux density ranging from 50 to 1200 G, and a value of h, defined as .pi.D.multidot.V.sub.p /(M.multidot.V.sub.m), of 2 or less wherein V.sub.p (mm/s) is the moving speed of the image-bearer, and D (mm), M, and V.sub.m (mm/s) are the outer diameter, the number of magnetic poles, and the peripheral speed of the permanent magnet, respectively.
摘要:
A sleeveless magnet roller is formed of at least magnetic powder and resin. It is so arranged that, letting a developing gap Ds be the gap between an image-bearing member for holding an electrostatic latent image and a developer conveying member and a doctor gap Dg be the gap between the developer conveying member and a developer's thickness regulating member, one obtains Ds-Dg=0.1 to 0.3 (mm) and Dg=0 to 0.4 (mm). For image formation, one- or two-component magnetic developer is used and a bias voltage, formed by superimposing AC bias voltage to DC bias voltage, is applied to the developing region.
摘要:
An Li--Mn type ferrite carrier for use in electrophotographic development comprising ferrite particles having a chemical composition of 3 to 15% of Li.sub.2 O, 5 to 35% of MnO and 60 to 90% of Fe.sub.2 O.sub.3, each in terms of percent by mole. The ferrite particles consisting essentially of crystal grains having an average grain size of 1 to 50 .mu.m. The surface of the crystal grains is provided with a minute roughness or unevenness during the production of the ferrite carrier. The minute roughness on the grain surface enhances the ability of the ferrite carrier to triboelectrically charge the toner and the bonding strength of the resin coating to the carrier surface.
摘要翻译:一种用于电子照相显影的Li-Mn型铁氧体载体,其包含化学组成为Li 2 O 3〜15%,MnO 5〜35%,Fe 2 O 3 60〜90%的铁氧体颗粒。 铁素体颗粒基本上由平均粒径为1至50μm的晶粒组成。 在制造铁氧体载体时,晶粒表面具有微小的粗糙度或不均匀性。 颗粒表面上的微小粗糙度增强了铁氧体载体对调色剂进行摩擦电荷的能力以及树脂涂层与载体表面的粘结强度。
摘要:
An image forming method includes the steps of charging a surface of a movable image-bearing member uniformly by using a roller charging means, forming an electrostatic latent image on the image-bearing member by carrying out an image exposure, delivering a magnetic developer which is attracted onto a surface of a sleeveless permanent magnetic member to a developing region located opposite to the electrostatic latent image formed on the image-bearing member, the sleeveless permanent magnetic member being formed with a plurality of magnetic poles provided on its surface and having a cylinder shape, developing the electrostatic latent image using the magnetic developer comprising a toner and magnetic carriers, the magnetic carriers having a volume resistivity of 10.sup.10 .OMEGA..cm or more, and transferring a toner image onto a transfer sheet by using a roller transfer means.
摘要:
A method for developing electrostatic latent image on a rotating photoconductive drum by a magnetic developer transported by a rotating developing roll disposed opposite to the photoconductive drum, the developing roll being made of a cylindrical permanent magnet having on circumferential surface thereof equispaced magnetic poles extending along the axial direction. In the method the magnetic poles are equispaced by an inter-pole pitch of 0.5-10 mm, the photoconductive drum and the developing roll are rotated so as to move in opposite directions in an developing zone, and the ratio of peripheral speeds of the developing roll and photoconductive drum are regulated within 1 to 5. By the above method, an electrophotographic imaging apparatus can be reduced in the size thereof while reproducing high-quality images.