Image transfer recording apparatus with resin coated drum

Abstract

An image transfer recording apparatus in which a recording drum on which an information signal is recorded by electrostatic recording means is provided with a surface layer of electrically insulating resin so that a powdery developer attaching to the electrostatic latent image formed on the surface of the recording drum can be completely transferred onto a recording sheet thereby to obtain a recorded image of good resolution.

We claim: 
     
       1. An apparatus for recording an image by transfer printing comprising a recording drum composed of a drum member of conductive metal and a layer of resin covering the surface of said drum member, said layer having a breakdown voltage of not less than 1 KV, a volume resistivity of more than 10 14  Ω cm, a surface resistivity of more than 10 14  Ω and no pinholes and preventing fused toner from attaching thereto, means for applying information .[.in the form of a signal voltage.]. .Iadd.of the image .Iaddend.to the surface of said recording drum .[.through a recording electrode thereby.]. to form a latent image of an electrical charge on the surface of said recording drum, developing means for selectively supplying a powdery developer .[.through the medium of a magnet drum.]. to the latent image .[.formed.]. .Iadd.to form a powder image .Iaddend.on .Iadd.the surface of .Iaddend.said recording drum, heating means for applying heat to a recording sheet, and means for transfer printing the powder image  .[.that is selectively attached to the latent image portion.]. on .Iadd.the surface of .Iaddend.said recording drum onto the heated recording sheet, and at the same time, fusing the powder to firmly fix .Iadd.the .Iaddend.same to the recording sheet under heat. 
     
     
       2. An apparatus for recording an image by transfer printing as defined in claim 1, in which said layer of resin is made of polyamide imide. 
     
     
       3. An apparatus for recording an image by transfer printing as defined in claim 1, in which said developing means .[.is further characterized by a support,.]. .Iadd.includes .Iaddend.a magnet drum which .[.comprised.]. .Iadd.comprises a support and .Iaddend.rubber magnets having the same axial length as the support and being embedded radially in the outer peripheral portion of the support, a sweeping plate being engaged at a portion thereof with the outer surface of .[.said.]. .Iadd.the .Iaddend.magnet drum for controlling the amount of the powdery developer .[.supply.]. .Iadd.supplied .Iaddend.to .[.the.]. .Iadd.said .Iaddend.recording drum, and a drive source for .Iadd.selectively .Iaddend.rotating the magnet drum in .[.either.]. .Iadd.both the .Iaddend.normal .[.or.]. .Iadd.and .Iaddend.reverse .Iadd.directions .Iaddend..[.direction.]. . 
     
     
       4. An apparatus for recording an image by transfer printing comprising a recording drum composed of a drum member of conductive metal and a layer of resin covering the surface of said drum member, said layer having a breakdown voltage of not less than 1 KV, a volume resistivity of more than 10 14  Ω cm, a surface resistivity of more than 10 14  .[.106.]. .Iadd.Ω.Iaddend. and no pinholes and preventing fused toner from attaching thereto, means for applying information .[.in the form of a signal voltage.]. .Iadd.of said image .Iaddend.to the surface of said recording drum .[.through a recording electrode thereby.]. to form a latent image of an electrical charge on the surface of said recording drum, developing means for selectively supplying a powdery developer .[.through the medium of a magnet drum.]. to the latent image .[.formed.]. .Iadd.to form a powder image .Iaddend.on .Iadd.the surface of .Iaddend.said recording drum, electrostatic charging means disposed adjacent to the back face of a recording sheet in contact with the .[.powdery developer selectively attached to the latent image.]. .Iadd.powder image to be transfer printed, .Iaddend.and residual charge erasing means disposed opposite to said recording drum for removing the .[.electrostatic force.]. .Iadd.electric charge .Iaddend.remaining on the surface of said recording drum after the powder image on .Iadd.the surface of .Iaddend.said recording drum has been transfer printed onto the recording sheet so as to make it possible for the following information .Iadd.of an image .Iaddend.to be applied to .Iadd.the surface of .Iaddend.said recording drum without cleaning the .[.powder image.]. .Iadd.powdery developer .Iaddend.remaining on the surface of .[.the.]. said recording drum .[.after the recording sheet transfer printed.]. . 
     
     
       5. An apparatus for recording an image by transfer printing as defined in claim 4, in which said layer of resin is made of polyamide imide. 
     
     
       6. An apparatus for recording an image by transfer printing as defined in claim 4, in which said developing means includes .[.a support,.]. a magnetic drum which comprises .Iadd.a support and .Iaddend.rubber magnets having the same axial length as the support and being embedded radially in the outer peripheral portion of the support, a sweeping plate being engaged at a portion thereof with the outer surface of .[.said.]. .Iadd.the .Iaddend.magnet drum for controlling the amount of the powdery developer .[.supply.]. .Iadd.supplied .Iaddend.to .[.the.]. .Iadd.said .Iaddend.recording drum, and a drive source for .Iadd.selectively .Iaddend.rotating the magnet drum in .[.either.]. .Iadd.both the .Iaddend.normal .[.or.]. .Iadd.and .Iaddend.reverse .[.direction.]. .Iadd.directions.Iaddend. . 
     
     
       7. An apparatus for recording an image by transfer printing comprising a plurality of sets each .[.consisting of.]. .Iadd.including .Iaddend.a recording drum having a layer of resin covered .[.in.]. .Iadd.on .Iaddend.the surface thereof, said layer having a breakdown voltage of not less than 1KV, a volume resistivity of more than 10 14  .[.106.]. .Iadd.Ω.Iaddend. cm, a surface resistivity of more than 10 14  Ω and no pinholes and preventing fused toner from attaching thereto, means for recording information .Iadd.of the image .Iaddend.on the surface of said recording drum .[.through the medium of electrostatic recording means thereby to form.]. .Iadd.in the form of .Iaddend.a latent image .Iadd.of an electrical charge .Iaddend.on the surface of said recording drum, and means for developing the latent image, said sets being arranged side by side equal and corresponding to the number of required primary colors .Iadd.of the image, .Iaddend..[.and demodulator.]. means for separating a multiple color signal .Iadd.of the image .Iaddend.into the respective primary color signals so that the primary color signals are .Iadd.simultaneously .Iaddend.recorded on the .Iadd.respective .Iaddend..[.surface.]. .Iadd.surfaces .Iaddend.of said recording drums by said .Iadd.respective .Iaddend.recording means and then developed by said .Iadd.respective .Iaddend.developing means and .[.a recording sheet is successively brought.]. .Iadd.means for successively bringing a recording sheet .Iaddend.into contact with the .Iadd.respective .Iaddend..[.surface.]. .Iadd.surfaces .Iaddend.of said recording drums for the transfer printing of the .[.color.]. .Iadd.developed .Iaddend.images onto the recording sheet. 
     
     
       8. An apparatus for recording an image by transfer printing as defined in claim 7, in which said layer of resin which covers each surface of said plurality of recording drums arranged side by side equal and corresponding to the number of required primary colors is made of polyamide imide. 
     
     
       9. An apparatus for recording an image by transfer printing comprising means for forming a latent image on a layer of resin and at a location opposite to the surface of a recording drum driven by an electric motor, said layer covering the surface of the recording drum and having a breakdown voltage not less than 1 KV, a volume resistivity of more than 10 14  Ω cm, a surface resistivity of more than 10 14  Ω and no pinholes and preventing fused toner from attaching thereto, developing means for selectively supplying a powdery developer to the latent image formed on .Iadd.the surface of .Iaddend.the recording drum, means for transfer printing the developed image formed by the .Iadd.powdery .Iaddend.developer selectively attached to the latent image onto a recording sheet contacting .[.said.]. .Iadd.the .Iaddend.recording drum, and residual charge erasing means disposed opposite to .[.said.]. .Iadd.the .Iaddend.recording drum for removing the electric charge remaining on .[.said.]. .Iadd.the .Iaddend.recording drum without cleaning the surface of .[.said.]. .Iadd.the .Iaddend.recording drum after the developed image has been transfer printed onto the recording sheet, in which said means for forming a latent image comprises a holder which is mounted on a slide rod so as to be movable in the axial direction of the recording drum and a recording .[.stulus.]. .Iadd.stylus .Iaddend.which is mounted on the holder and one end of which contacts the surface of the recording drum only in the case of a signal voltage being applied, said developing means comprises a magnet drum which is housed in a casing and is mounted so as to be .Iadd.selectively .Iaddend.rotatable in .[.either.]..Iadd.both the .Iaddend.normal .[.or.]. .Iadd.and .Iaddend.reverse .Iadd.directions.Iaddend..[.direction.]., a powdery developer which is supplied to the recording drum by the magnet drum only in the case of the latent image being developed and a sweeping plate which is engaged at a portion thereof with the outer surface of the magnet drum for controlling the amount of the powdery developer .[.supply.]. .Iadd.supplied .Iaddend.to the recording drum in response to the rotating direction of the magnet drum, said means for transfer printing comprises .[.a recording sheet which is brought into contact with the recording drum by.]. a guide roller .Iadd.which brings the recording sheet into contact with the recording drum .Iaddend.and a charging means disposed on the back side of the recording sheet, and said residual charge erasing means comprises an electrode which is covered by a cover and one end of which is opposed to the recording drum .Iadd.and the other end of which is supported by the cover .Iaddend.through an insulator.