Charged particle containment apparatus

Claim 3

An apparatus according to claim 1, wherein said holding means is positioned closely adjacent to the photoconductive member.

Claim 4

An apparatus according to claim 2, wherein the photoconductive member moves relative to said holding means, said holding means being positioned so as to increase the impedance of air flowing from the chamber of said housing to reduce the escape rate of the charged particles therefrom.

Claim 5

An apparatus according to claim 3, wherein said holding means includes: a frame mounted on said housing; and a plate mounted slidably in said frame, said plate being readily removable from said frame so as to clean therefrom charged particles adhering thereto.

Claim 6

An apparatus according to claim 4, wherein: said frame is made from an electrically conductive material; and said plate is made from an electrically conductive material.

Claim 7

An apparatus according to claim 4, wherein said biasing means electrically biases said housing to substantially the same potential as said plate.

Claim 8

An electrophotographic printing machine of the type having a photoconductive member, a corona generating device adapted to charge at least a portion of the photoconductive member to a substantially uniform level, and an imaging system arranged to focus a light image of an original document onto the charged portion of the photoconductive member to record an image voltage region and a non-image voltage region thereon, wherein the improvement includes: a housing defining a chamber for storing a developer mixture comprising carrier granules having charged toner particles adhering triboelectrically thereto; means, positioned interiorly of the chamber of said housing, for transporting the developer mixture from the chamber of said housing to the image voltage region so that the toner particles are attracted thereto to form a toner powder image on the photoconductive member; means, positioned exteriorly of the chamber of said housing, for holding charged toner particles scattered from the chamber of said housing; and means for electrically biasing said holding means to a voltage level having a magnitude intermediate the magnitude of the image voltage level and the magnitude of the non-image voltage level so as to form an electrical field between the non-image voltage region and said holding means which attracts charged toner particles of one polarity to said holding means and an electrical field between the image voltage region and said holding means which repels the charged toner particles from said holding means to the image voltage region of the photoconductive member.

Claim 9

An electrophotographic printing machine of the type having a photoconductive member, a corona generating device adapted to charge at least a portion of the photoconductive member to a substantially uniform level, and an imaging system arranged to focus a light image of an original document onto the charged portion of the photoconductive member to record an image voltage region and a non-image voltage region thereon, wherein the improvement includes: a housing defining a chamber for storing a developer mixture comprising carrier granules having charged toner particles adhering triboelectrically thereto; means, positioned interiorly of the chamber of said housing, for transporting the developer mixture from the chamber of said housing to the image voltage region so that the toner particles are attracted thereto to form a toner powder image on the photoconductive member; means, positioned exteriorly of the chamber of said housing, for holding charged toner particles scattered from the chamber of said housing; and means for electrically biasing said holding means to a voltage level having a magnitude intermediate the magnitude of the image voltage level and the magnitude of the non-image voltage level so as to form an electrical field between the non-image voltage region and said holding means which attracts charged toner particles of one polarity to said holding means and an electrical field between the image voltage region and said holding means which repels the charged toner particles from said holding means to the image voltage region of the photoconductive member.

Claim 10

A printing machine according to claim 7 wherein said holding means is positioned closely adjacent to the photoconductive member.

Claim 11

A printing machine according to claim 8, wherein the photoconductive member moves relative to said holding means, said holding means being positioned so as to increase the impedance of air flowing from the chamber of said housing to reduce the escape rate of the charged toner particles therefrom.

Claim 12

A printing machine according to claim 9, wherein said holding means is interposed between the imaging system and said transporting means.

Claim 13

A printing machine according to claim 10, wherein said holding means includes: a frame mounted on said housing; and a plate mounted slidably in said frame, said plate being readily removable from the frame so as to clean therefrom charged toner particles adhering thereto.

Claim 14

A printing machine according to claim 11, wherein: said frame is made from an electrically conductive material; and said plate is made from an electrically conductive material.

Claim 15

A printing machine according to claim 11, wherein said biasing means electrically biases said housing to substantially the same potential as said plate.

Claim 18

An apparatus according to claim 14 wherein said holding means is positioned closely adjacent to the photoconductive member.

Claim 19

An apparatus according to claim 15, wherein the photoconductive member moves relative to said holding means, said holding means being positioned so as to increase the impedance of air flowing from the chamber of said housing to reduce the escape rate of the charged particles therefrom.

Claim 20

An apparatus according to claim 16, wherein said holding means includes: a frame mounted on said housing; and a plate mounted slidably in said frame, said plate being readily removable from said frame so as to clean therefrom charged particles adhering thereto.

Claim 21

An apparatus according to claim 17, wherein: said frame is made from an electrically conductive material; and said plate is made from an electrically conductive material.

Claim 22

An apparatus according to claim 17, wherein said biasing means electrically biases said housing to substantially the same potential as said plate.

Claim 23

An electrophotographic printing machine of the type having a photoconductive member, a corona generating device adapted to charge at least a portion of the photoconductive member to a substantially uniform level, and an imaging system arranged to focus a light image of an original document onto the charged portion of the photoconductive member to record an image voltage region thereon, wherein the improvement includes: a housing defining a chamber for storing a developer mixture comprising carrier granules having charged toner particles adhering triboelectrically thereto; means, positioned interiorly of said housing, for transporting the developer mixture from the chamber of said housing to the image voltage region so that the toner particles are attached thereto to form a toner powder image on the photoconductive member; means, positioned exteriorly of said housing, for holding charged toner particles scattered from the chamber of said housing; and means for electrically biasing said holding means to a voltage level having a magnitude greater than the magnitude of the image voltage level so as to form an electrical field between the photoconductive member and said holding means which attracts charged toner particles of one polarity to said holding means.

Claim 24

An electrophotographic printing machine of the type having a photoconductive member, a corona generating device adapted to charge at least a portion of the photoconductive member to a substantially uniform level, and an imaging system arranged to focus a light image of an original document onto the charged portion of the photoconductive member to record an image voltage region thereon, wherein the improvement includes: a housing defining a chamber for storing a developer mixture comprising carrier granules having charged toner particles adhering triboelectrically thereto; means, positioned interiorly of said housing, for transporting the developer mixture from the chamber of said housing to the image voltage region so that the toner particles are attached thereto to form a toner powder image on the photoconductive member; means, positioned exteriorly of said housing, for holding charged toner particles scattered from the chamber of said housing; and means for electrically biasing said holding means to a voltage level having a magnitude greater than the magnitude of the image voltage level so as to form an electrical field between the photoconductive member and said holding means which attracts charged toner particles of one polarity to said holding means.

Claim 25

A printing machine according to claim 20, wherein said holding means is positioned closely adjacent to the photoconductive member.

Claim 26

A printing machine according to claim 21, wherein the photoconductive member moves relative to said holding means, said holding means being positioned so as to increase the impedance of air flowing from the chamber of said housing to reduce the escape rate of the charged toner particles therefrom.

Claim 27

A printing machine according to claim 22, wherein said holding means is interposed between the imaging system and said transporting means.

Claim 28

A printing machine according to claim 23, wherein said holding means includes: a frame mounted on said housing; and a plate mounted slidably in said frame, said plate being readily removable from the frame so as to clean therefrom charged toner particles adhering thereto.

Claim 29

A printing machine according to claim 24, wherein: said frame is made from an electrically conductive material; and said plate is made from an electrically conductive material.

Claim 30

A printing machine according to claim 24, wherein said biasing means electrically biases said housing to substantially the same potential as said plate.