Electroprinting device

Claim 2

An electroprinting apparatus for making a selected number of copies of an original comprising: feeding means for feeding sheet material to be formed into a master-sheet during use of the apparatus; charging means for applying an electrostatic charge on the sheet material fed by said feeding means; means including an optical system for optically forming a latent electrostatic image of an original to be copied on the electrostatically charged sheet thereby forming a master-sheet containing thereon the latent image; first developing means for developing the latent image; fixing means for permanently fixing the developed image on the master-sheet; rotary means for receiving the master-sheet from said fixing means and angularly advancing same to successive work stations, said rotary means comprising a unidirectionally and rotationally driven cylindrical drum for receiving and carrying thereon the master-sheet; recharging means disposed adjacent the periphery of said drum and defining one work station for applying an electrostatic charge on the master-sheet as same is angularly advanced by said drum to recharge the master-sheet and form a latent electrostatic image conforming to the developed and permanently fixed image contained on the master-sheet; second developing means disposed adjacent the periphery of said drum circumferentially spaced from said recharging means in the rotational direction of said drum and defining another work station for applying toner to the master-sheet as same is angularly advanced by said drum to develop the recharged latent image; a rotatable transcription roller disposed adjacent the periphery of said drum to define a nip therebetween and circumferentially spaced from said second developing means in the rotational direction of said drum and defining a further work station; means for feeding copy paper during use of the apparatus into said nip in synchronism with the rotational speed of said drum; voltage applying means for applying suitable voltage between said drum and said transcription roller to effect electrostatic transfer of the toner from the recharged mastersheet to the copy paper to thereby form a visible image on the copy paper conforming to the original; and means for permanently fixing the visible image on the copy paper; whereby a copy of the original is made in one revolution of said drum.

Claim 3

An electroprinting printing apparatus according to claim 1; including cleaning means disposed adjacent the periphery of said drum circumferentially spaced from said transcription roller in the rotational direction of said drum and defining still another work station for cleaning residual toner remaining on the master-sheet after each toner transfer to thereby prepare the master-sheet for recharging so that another copy can be made.

Claim 4

An electroprinting printing apparatus according to claim 1; including cleaning means disposed adjacent the periphery of said drum at a location between said transcription roller and said recharging means in circumferentially spaced relationship from the former with respect to the rotational direction of said drum and defining still another work station for cleaning residual toner remaining on the master-sheet after each toner transfer to thereby prepare the master-sheet for recharging so that another copy can be made.

Claim 5

An electroprinting apparatus for making a selected number of copies of an original comprising: feeding means for feeding sheet material to be formed into a master-sheet durinG use of the apparatus; charging means for applying an electrostatic charge on the sheet material fed by said feeding means; means including an optical system for optically forming a latent electrostatic image of an original to be copied on the electrostatically charged sheet thereby forming a master-sheet containing thereon the latent image; rotary means for receiving the master-sheet and angularly advancing same to successive work stations, said rotary means comprising a unidirectionally and rotationally driven cylindrical drum for receiving and carrying thereon the master-sheet; developing means disposed adjacent the periphery of said drum and defining one work station for developing the latent image as the master-sheet is angularly advanced by said drum; fixing means disposed adjacent the periphery of said drum circumferentially spaced from said developing means in the rotational direction of said drum and defining another work station for permanently fixing the developed image on the master-sheet as same is angularly advanced by said drum whereby the latent image is developed and fixed in one revolution of said drum; recharging means disposed adjacent the periphery of said drum at a location between said developing means and said fixing means in circumferentially spaced relationship from the latter with respect to the rotational direction of said drum and defining a further work station for applying an electrostatic charge on the master-sheet as same is angularly advanced by said drum to recharge the master-sheet and form a latent electrostatic image conforming to the developed and permanently fixed image contained on the master-sheet; developing means consisting of said first-mentioned developing means for applying toner to the master-sheet as same is angularly advanced by said drum to develop the recharged latent image; a rotatable transcription roller disposed adjacent the periphery of said drum to define a nip therebetween and located between said developing means and said fixing means in circumferentially spaced relationship from the former with respect to the rotational direction of said drum and defining a still further work station; means for feeding copy paper during use of the apparatus into said nip in synchronism with the rotational speed of said drum; voltage applying means for applying suitable voltage between said drum and said transcription roller to effect electrostatic transfer of the toner from the recharged master-sheet to the copy paper to thereby form a visible image on the copy paper conforming to the original; and means for permanently fixing the visible image on the copy paper; whereby the first copy of the original is made in two revolutions of said drum and each successive copy is made in one revolution of said drum.

Claim 6

An electroprinting apparatus for making a selected number of copies of an original comprising: feeding means for feeding sheet material to be formed into a master-sheet durinG use of the apparatus; charging means for applying an electrostatic charge on the sheet material fed by said feeding means; means including an optical system for optically forming a latent electrostatic image of an original to be copied on the electrostatically charged sheet thereby forming a master-sheet containing thereon the latent image; rotary means for receiving the master-sheet and angularly advancing same to successive work stations, said rotary means comprising a unidirectionally and rotationally driven cylindrical drum for receiving and carrying thereon the master-sheet; developing means disposed adjacent the periphery of said drum and defining one work station for developing the latent image as the master-sheet is angularly advanced by said drum; fixing means disposed adjacent the periphery of said drum circumferentially spaced from said developing means in the rotational direction of said drum and defining another work station for permanently fixing the developed image on the master-sheet as same is angularly advanced by said drum whereby the latent image is developed and fixed in one revolution of said drum; recharging means disposed adjacent the periphery of said drum at a location between said developing means and said fixing means in circumferentially spaced relationship from the latter with respect to the rotational direction of said drum and defining a further work station for applying an electrostatic charge on the master-sheet as same is angularly advanced by said drum to recharge the master-sheet and form a latent electrostatic image conforming to the developed and permanently fixed image contained on the master-sheet; developing means consisting of said first-mentioned developing means for applying toner to the master-sheet as same is angularly advanced by said drum to develop the recharged latent image; a rotatable transcription roller disposed adjacent the periphery of said drum to define a nip therebetween and located between said developing means and said fixing means in circumferentially spaced relationship from the former with respect to the rotational direction of said drum and defining a still further work station; means for feeding copy paper during use of the apparatus into said nip in synchronism with the rotational speed of said drum; voltage applying means for applying suitable voltage between said drum and said transcription roller to effect electrostatic transfer of the toner from the recharged master-sheet to the copy paper to thereby form a visible image on the copy paper conforming to the original; and means for permanently fixing the visible image on the copy paper; whereby the first copy of the original is made in two revolutions of said drum and each successive copy is made in one revolution of said drum.