Color electrophotographic process using photoconductive particles in liquid developer

Claim 1

The method of producing a multicolor reproduction of an original colored object comprising the steps of: a. charging a photoconductive insulating layer; b. exposing the charged layer to said original colored object through a colored filter to form a first primary color coded electrostatic latent image on said layer; c. developing said first electrostatic latent image with a liquid developer having a color complementary to said first color coded latent image, said liquid developer comprising a carrier liquid having a dielectric constant of less than about 3.4 and a volume resistivity of greater than about 10 10 ohm-cm so as not to affect an electrostatic latent image formed on an insulating layer, and dispersed in said carrier liquid, a mixture of discrete colored toner particles and discrete photoconductive particles, said colored toner particles substantially lacking the property of photoconductivity and comprising a colorant selected from the group consisting of a pigment and a dye having a thin layer of a resin absorbed therearound, said photoconductive particles comprising particulate photoconductive material having a thin layer of a resin absorbed therearound, said thin layer of said resin absorbed therearound said particulate photoconductive material being sufficiently thin to facilitate exposure of said particulate photoconductive material and dissipate any charge thereon, said photoconductive particles being present in an amount of from about 5 to about 104 parts by weight for every 100 parts by weight of said colored toner particles; d. contacting said photoconductive insulating layer with an insulating liquid other than the developer liquid to neutralize any residual charge in the portion of said layer developed in step (c); e. charging said photoconductive insulating layer; f. exposing the charged layer to said original colored object through a colored filter to form a second primary color coded electrostatic latent image on said layer; g. developing said second electrostatic latent image with a liquid developer having a color complementary to said second color coded image; said liquid developer comprising a carrier liquid having a dielectric constant of less than about 3.4 and a volume resistivity of greater than about 10 10 ohm-cm so as not to affect an electrostatic latent image formed on an insulating layer, and dispersed in said carrier liquid, a mixture of discrete colored toner particles and discrete photoconductive particles, said colored toner particles substantially lacking the property of photoconductivity and comprising a colorant selected from the group consisting of a pigment and a dye having a thin layer of a resin absorbed therearound, said photoconductive particles comprising particulate photoconductive material having a thin layer of a resin absorbed therearound, said thin layer of said resin absorbed therearound said particulate photoconductive material being sufficiently thin to facilitate exposure of said particulate photoconductive material and dissipate any charge thereon, said photoconductive particles being present in an amount of from about 5 to about 104 parts by weight for every 100 parts by weight of said colored toner particles; h. contacting said photoconductive insulating layer with an insulating liquid other than the developer liquid to neutralize any residual charge in the portion of said layer developed in step (g); i. charging said photoconductive insulating layer; j. exposing the charged layer to said original colored object through a colored filter to form a third primary color coded electrostatic latent image on said layer; and k. developing said third electrostatic latent image with a liquid developer having a color complementary to said third color coded image, said liquid developer comprising an insulating liquid having dispersed therein colored particles.

Claim 2

The method of producing a multicolor reproduction of an original colored object comprising the steps of: a. charging a photoconductive insulating layer; b. exposing the charged layer to said original colored object through a colored filter to form a first primary color coded electrostatic latent image on said layer; c. developing said first electrostatic latent image with a liquid developer having a color complementary to said first color coded latent image, said liquid developer comprising a carrier liquid having a dielectric constant of less than about 3.4 and a volume resistivity of greater than about 10 10 ohm-cm so as not to affect an electrostatic latent image formed on an insulating layer, and dispersed in said carrier liquid, a mixture of discrete colored toner particles and discrete photoconductive particles, said colored toner particles substantially lacking the property of photoconductivity and comprising a colorant selected from the group consisting of a pigment and a dye having a thin layer of a resin absorbed therearound, said photoconductive particles comprising particulate photoconductive material having a thin layer of a resin absorbed therearound, said thin layer of said resin absorbed therearound said particulate photoconductive material being sufficiently thin to facilitate exposure of said particulate photoconductive material and dissipate any charge thereon, said photoconductive particles being present in an amount of from about 5 to about 104 parts by weight for every 100 parts by weight of said colored toner particles; d. contacting said photoconductive insulating layer with an insulating liquid other than the developer liquid to neutralize any residual charge in the portion of said layer developed in step (c); e. charging said photoconductive insulating layer; f. exposing the charged layer to said original colored object through a colored filter to form a second primary color coded electrostatic latent image on said layer; g. developing said second electrostatic latent image with a liquid developer having a color complementary to said second color coded image; said liquid developer comprising a carrier liquid having a dielectric constant of less than about 3.4 and a volume resistivity of greater than about 10 10 ohm-cm so as not to affect an electrostatic latent image formed on an insulating layer, and dispersed in said carrier liquid, a mixture of discrete colored toner particles and discrete photoconductive particles, said colored toner particles substantially lacking the property of photoconductivity and comprising a colorant selected from the group consisting of a pigment and a dye having a thin layer of a resin absorbed therearound, said photoconductive particles comprising particulate photoconductive material having a thin layer of a resin absorbed therearound, said thin layer of said resin absorbed therearound said particulate photoconductive material being sufficiently thin to facilitate exposure of said particulate photoconductive material and dissipate any charge thereon, said photoconductive particles being present in an amount of from about 5 to about 104 parts by weight for every 100 parts by weight of said colored toner particles; h. contacting said photoconductive insulating layer with an insulating liquid other than the developer liquid to neutralize any residual charge in the portion of said layer developed in step (g); i. charging said photoconductive insulating layer; j. exposing the charged layer to said original colored object through a colored filter to form a third primary color coded electrostatic latent image on said layer; and k. developing said third electrostatic latent image with a liquid developer having a color complementary to said third color coded image, said liquid developer comprising an insulating liquid having dispersed therein colored particles.

Claim 9

The method of producing a reproduction of a colored object comprising the steps of: a. charging a photoconductive insulating layer; b. exposing said layer to a wavelength of light corresponding to a primary color to produce an electrostatic latent image; c. developing said electrostatic latent image with a liquid developer comprising an insulating liquid having a dielectric constant of less than about 3.4 and a volume resistivity of greater than about 10 10 ohm-cm so as not to affect an electrostatic latent image formed on said insulating layer, and dispersed therein a mixture of discrete photoconductive particles and discrete toner particles complementary to the radiation of exposure in step (b); said colored toner particles substantially lacking the property of photoconductivity and comprising a colorant selected from the group consisting of a pigment and a dye having a thin layer of a resin absorbed therearound, said photoconductive particles comprising particulate photoconductive material having a thin layer of a resin absorbed therearound, said thin layer of said resin absorbed therearound said particulate photoconductive material being sufficiently thin to facilitate exposure to said particulate photoconductive material and dissipate any charge thereon, said photoconductive particles being present in an amount of from about 5 to about 104 parts by weight for every 100 parts by weight of said colored toner particles; d. contacting said photoconductive insulating layer with an insulating liquid other than the developer liquid to neutralize any residual charge in the portion of said layer developed in step (c); e. charging said photoconductive insulating layer; f. exposing said layer to a wavelength of light corresponding to a primary color different from that of step (b) to produce an electrostatic latent image; g. developing said electrostatic latent image with a liquid developer as in step (c) wherein said liquid developer particles are complementary to the radiation of exposure in step (f); h. contacting said photoconductive insulating layer with an insulating liquid other than the developer liquid to neutralize any residual charge in the portion of said layer developed in step (g); i. charging said photoconductive insulating layer; j. exposing said layer to a wavelength of light corresponding to a primary color different from that of steps (b) and (f) to produce an electrostatic latent image; and k. developing said electrostatic latent image with a liquid developer as in step (c) wherein said liquid developer particles are complementary to the radiation of exposure in step (j).

Claim 10

The method of producing a reproduction of a colored object comprising the steps of: a. charging a photoconductive insulating layer; b. exposing said layer to a wavelength of light corresponding to a primary color to produce an electrostatic latent image; c. developing said electrostatic latent image with a liquid developer comprising an insulating liquid having a dielectric constant of less than about 3.4 and a volume resistivity of greater than about 10 10 ohm-cm so as not to affect an electrostatic latent image formed on said insulating layer, and dispersed therein a mixture of discrete photoconductive particles and discrete toner particles complementary to the radiation of exposure in step (b); said colored toner particles substantially lacking the property of photoconductivity and comprising a colorant selected from the group consisting of a pigment and a dye having a thin layer of a resin absorbed therearound, said photoconductive particles comprising particulate photoconductive material having a thin layer of a resin absorbed therearound, said thin layer of said resin absorbed therearound said particulate photoconductive material being sufficiently thin to facilitate exposure to said particulate photoconductive material and dissipate any charge thereon, said photoconductive particles being present in an amount of from about 5 to about 104 parts by weight for every 100 parts by weight of said colored toner particles; d. contacting said photoconductive insulating layer with an insulating liquid other than the developer liquid to neutralize any residual charge in the portion of said layer developed in step (c); e. charging said photoconductive insulating layer; f. exposing said layer to a wavelength of light corresponding to a primary color different from that of step (b) to produce an electrostatic latent image; g. developing said electrostatic latent image with a liquid developer as in step (c) wherein said liquid developer particles are complementary to the radiation of exposure in step (f); h. contacting said photoconductive insulating layer with an insulating liquid other than the developer liquid to neutralize any residual charge in the portion of said layer developed in step (g); i. charging said photoconductive insulating layer; j. exposing said layer to a wavelength of light corresponding to a primary color different from that of steps (b) and (f) to produce an electrostatic latent image; and k. developing said electrostatic latent image with a liquid developer as in step (c) wherein said liquid developer particles are complementary to the radiation of exposure in step (j).

Claim 13

The method of producing a reproduction of a colored object comprising the steps of: a. charging a photoconductive insulating layer; b. exposing said layer to a wavelength of light corresponding to a color to produce an electrostatic latent image; c. developing said electrostatic latent image with a liquid developer comprising a carrier liquid having a dielectric constant of less than about 3.4 and a volume resistivity of greater than about 10 10 ohm-cm so as not to affect an electrostatic latent image formed on an insulating layer, and dispersed in said carrier liquid, a mixture of discrete colored toner particles and discrete photoconductive particles, said colored toner particles substantially lacking the property of photoconductivity and comprising a colorant selected from the group consisting of a pigment and a dye having a thin layer of a resin absorbed therearound, said photoconductive particles comprising particulate photoconductive material having a thin layer of a resin absorbed therearound, said thin layer of said resin absorbed therearound said particulate photoconductive material being sufficiently thin to facilitate exposure of said particulate photoconductive material and dissipate any charge thereon, said photoconductive particles being present in an amount of from about 5 to about 104 parts by weight for every 100 parts by weight of said colored toner particles, said toner particles being complementary to the radiation of exposure in step (b); d. contacting said photoconductive insulating layer with an insulating liquid other than the developer liquid to neutralize any residual charge in the portion of said layer developed in (c); and e. repeating steps (a), (b), (c), and (d) at least one additional time wherein the wavelength of light in the exposure step is other than that of step (b).

Claim 14

The method of producing a reproduction of a colored object comprising the steps of: a. charging a photoconductive insulating layer; b. exposing said layer to a wavelength of light corresponding to a color to produce an electrostatic latent image; c. developing said electrostatic latent image with a liquid developer comprising a carrier liquid having a dielectric constant of less than about 3.4 and a volume resistivity of greater than about 10 10 ohm-cm so as not to affect an electrostatic latent image formed on an insulating layer, and dispersed in said carrier liquid, a mixture of discrete colored toner particles and discrete photoconductive particles, said colored toner particles substantially lacking the property of photoconductivity and comprising a colorant selected from the group consisting of a pigment and a dye having a thin layer of a resin absorbed therearound, said photoconductive particles comprising particulate photoconductive material having a thin layer of a resin absorbed therearound, said thin layer of said resin absorbed therearound said particulate photoconductive material being sufficiently thin to facilitate exposure of said particulate photoconductive material and dissipate any charge thereon, said photoconductive particles being present in an amount of from about 5 to about 104 parts by weight for every 100 parts by weight of said colored toner particles, said toner particles being complementary to the radiation of exposure in step (b); d. contacting said photoconductive insulating layer with an insulating liquid other than the developer liquid to neutralize any residual charge in the portion of said layer developed in (c); and e. repeating steps (a), (b), (c), and (d) at least one additional time wherein the wavelength of light in the exposure step is other than that of step (b).