Excess developer removal apparatus

Claim 2

Apparatus for removing excess developer liquid from a moving image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: an elongated barrier member; means for mounting said barrier member with the length thereof extending across the portion of said surface bearing said image, with a substantially unpressurized region immediately in advance of the leading portion of said barrier member and adjacent to said developer layer, and with a spacing between the leading portion of said barrier member and said surface which is less than the thickness of said developer layer to intercept said layer; and means for forming an air curtain behind the leading portion of said barrier member in the region of adjacency of said member and said surface.

Claim 3

Apparatus as in claim 1 in which said air curtain forming means comprises means for forming a transverse slit in said barrier member between the leading and trailing portions and means for maintaining the interior of said slit at a pressure greater than atmospheric pressure.

Claim 4

Apparatus as in claim 2 in which said pressure maintaining means maintains the interior of said slit at a pressure from 5 to 10 inches of water greater than atmospheric pressure.

Claim 5

Apparatus as in claim 2 in which said pressure maintaining means supplies the interior of said slit with air at a rate between 2 and 4 cubic feet per minute.

Claim 6

Apparatus as in claim 2 in which the width of said slit is substantially greater than the spacing of said barrier member from said surface.

Claim 7

Apparatus as in claim 2 in which the width of said slit is 5 to 10 times the spacing of said barrier member from said surface.

Claim 8

Apparatus as in claim 6 in which the width of said slit is 0.02 inch.

Claim 9

Apparatus as in claim 2 in which the leading and trailing portions of said barrier member are generally parallel to the image-bearing surface.

Claim 10

Apparatus as in claim 1 in which said mounting means comprises a pair of rollers rotatably attached to the barrier member at opposite ends thereof, and means for biasing the rollers against the image-bearing surface.

Claim 11

Apparatus as in claim 1 in which the spacing between the barrier member and the leading portion of said image-bearing surface is between 0.001 and 0.002 inch.

Claim 12

Apparatus as in claim 1, further including means spaced away from the image-bearing surface for cleaning the portions of said barrier member adjacent to the image-bearing surface, said mounting means comprising means for moving said portions to the cleaning means.

Claim 13

Apparatus as in claim 1 in which said barrier member and air curtain forming means comprise: a generally cylindrical member having a hollow interior and an axially extending exit slit communicating with said interior and having an axially extending groove formed in the outer surface along each side of the exit slit; and means for maintaining said interior at a pressure greater than atmospheric pressure.

Claim 14

Apparatus for removing excess developer liquid from an image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a mechanical barrier member extending across said surface; means mounting said member in spaced relationship to said surface with a spacing between said barrier and said surface which is less than said certain thickness; means for moving said surface and said barrier member relative to each other whereby said barrier member has a trailing portion with reference to the direction of said relative movement; means forming a relatively low-pressure air barrier in the region of adjacency of the barrier member and said surface to inhibit wetting of said trailing portion of said barrier member by said developer liquid; and means spaced away from said image-bearing surface for cleaning the portions of said barrier member adjacent to the image-bearing surface, said mounting means comprising means for moving said portions to the cleaning means.

Claim 15

Apparatus for removing excess developer liquid from an image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a mechanical barrier member extending across said surface; means mounting said member in spaced relationship to said surface with a spacing between said barrier and said surface which is less than said certain thickness; means for moving said surface and said barrier member relative to each other whereby said barrier member has a trailing portion with reference to the direction of said relative movement; means forming a relatively low-pressure air barrier in the region of adjacency of the barrier member and said surface to inhibit wetting of said trailing portion of said barrier member by said developer liquid; and means spaced away from said image-bearing surface for cleaning the portions of said barrier member adjacent to the image-bearing surface, said mounting means comprising means for moving said portions to the cleaning means.

Claim 16

Apparatus as in claim 13 in which said cleaning means comprises a spongy pad.

Claim 17

Apparatus as in claim 13 in which the moving means rotates the barrier member on the axis of said rollers.

Claim 18

Apparatus for removing excess developer liquid from a moving image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a mechanical barrier member extending across said surface and having leading and trailing portions relative to the direction of movement of said surface, said leading and trailing portions being spaced from one another to form a transverse slit; means mounting said member in spaced relationship to said surface with a spacing between said barrier member and said surface which is substantially less than said predetermined thickness, said slit having a width substantially greater than the spacing of said member from said surface; and means for maintaining the interior of said slit at a pressure slightly greater than atmospheric pressure to form a relatively low-pressure air barrier in the region of adjacency of the barrier member and said surface to inhibit wetting of said trailing portion of said barrier member by said developer liquid.

Claim 19

Apparatus for removing excess developer liquid from a moving image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a mechanical barrier member extending across said surface and having leading and trailing portions relative to the direction of movement of said surface, said leading and trailing portions being spaced from one another to form a transverse slit; means mounting said member in spaced relationship to said surface with a spacing between said barrier member and said surface which is substantially less than said predetermined thickness, said slit having a width substantially greater than the spacing of said member from said surface; and means for maintaining the interior of said slit at a pressure slightly greater than atmospheric pressure to form a relatively low-pressure air barrier in the region of adjacency of the barrier member and said surface to inhibit wetting of said trailing portion of said barrier member by said developer liquid.

Claim 20

In a copying machine in which a surface bearing a latent electrostatic image is developed by applying liquid developer to the surface at a developing station and is then moved with a relatively thin adhering developer layer to an excess developer removal station, apparatus at said removal station including, in combination: an elongated barrier member; means for mounting said barrier member with the length thereof extending across the portion of said surface bearing said image, with a region immediately in advance of said leading portion of said barrier member in which said developer layer is directly exposed to the ambient atmosphere, and with a spacing between the leading portion of said barrier member and said surface which is less than the thickness of said developer layer to intercept said layer; and means for forming an air curtain behind the leading portion of said barrier member in the region of adjacency of said member and said surface.

Claim 21

In a copying machine in which a surface bearing a latent electrostatic image is developed by applying liquid developer to the surface at a developing station and is then moved with a relatively thin adhering developer layer to an excess developer removal station, apparatus at said removal station including, in combination: an elongated barrier member; means for mounting said barrier member with the length thereof extending across the portion of said surface bearing said image, with a region immediately in advance of said leading portion of said barrier member in which said developer layer is directly exposed to the ambient atmosphere, and with a spacing between the leading portion of said barrier member and said surface which is less than the thickness of said developer layer to intercept said layer; and means for forming an air curtain behind the leading portion of said barrier member in the region of adjacency of said member and said surface.

Claim 22

Apparatus for removing excess developer liquid from a moving image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: an elongated edge; means for mounting said edge with the length thereof extending across the portion of said surface bearing said image with a spacing between said edge and said surface which is less than the thickness of said developer layer to intercept said layer, the region of adjacency of said surface and said edge having no substantial extent in the direction of surface movement; and means for creating a pressurized region immediately behind said edge to form an air curtain in the region of adjacency of said edge and said edge and said surface.

Claim 23

Apparatus for removing excess developer liquid from a moving image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: an elongated edge; means for mounting said edge with the length thereof extending across the portion of said surface bearing said image with a spacing between said edge and said surface which is less than the thickness of said developer layer to intercept said layer, the region of adjacency of said surface and said edge having no substantial extent in the direction of surface movement; and means for creating a pressurized region immediately behind said edge to form an air curtain in the region of adjacency of said edge and said edge and said surface.

Claim 24

Apparatus for removing excess developer liquid from an image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a mechanical barrier member extending across said surface; means mounting said member in spaced relationship to said surface with a spacing between said barrier member and said surface which is less than said certain thickness; means for moving said surface and said barrier member relative to each other whereby said barrier member has a leading portion and a trailing portion with reference to the direction of said relative movement; and means for forming a relatively low-pressure air barrier in the region of adjacency of the barrier member and said surface to inhibit wetting of said trailing portion of said barrier member by said developer liquid, said air barrier means comprising means for forming a transverse slit in said barrier member between said leading and trailing portions and means for maintaining the interior of said slit at a pressure greater than atmospheric pressure, said pressure maintaining means maintaining the interior of said slit at a pressure from 5 to 10 inches of water greater than atmospheric pressure.

Claim 25

Apparatus for removing excess developer liquid from an image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a mechanical barrier member extending across said surface; means mounting said member in spaced relationship to said surface with a spacing between said barrier member and said surface which is less than said certain thickness; means for moving said surface and said barrier member relative to each other whereby said barrier member has a leading portion and a trailing portion with reference to the direction of said relative movement; and means for forming a relatively low-pressure air barrier in the region of adjacency of the barrier member and said surface to inhibit wetting of said trailing portion of said barrier member by said developer liquid, said air barrier means comprising means for forming a transverse slit in said barrier member between said leading and trailing portions and means for maintaining the interior of said slit at a pressure greater than atmospheric pressure, said pressure maintaining means maintaining the interior of said slit at a pressure from 5 to 10 inches of water greater than atmospheric pressure.

Claim 26

Apparatus for removing excess developer liquid form an image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a mechanical barrier member extending across said surface; means mounting said member in spaced relationship to said surface with a spacing between said barrier member and said surface which is less than said certain thickness; means for moving said surface and said barrier member relative to each other whereby said barrier member has a leading portion and a trailing portion with reference to the direction of said relative movement; and means for forming a relatively low-pressure air barrier in the region of adjacency of the barrier member and said surface to inhibit wetting of said trailing portion of said member by said developer liquid, said air barrier forming means comprising means for forming a transverse slit in said barrier member between said leading and trailing portions and means for maintaining the interior of said slit at a pressure greater than atmospheric pressure, said pressure maintaining means supplying the interior of said slit with air at a rate between 2 and 4 cubic feet per minute.

Claim 27

Apparatus for removing excess developer liquid form an image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a mechanical barrier member extending across said surface; means mounting said member in spaced relationship to said surface with a spacing between said barrier member and said surface which is less than said certain thickness; means for moving said surface and said barrier member relative to each other whereby said barrier member has a leading portion and a trailing portion with reference to the direction of said relative movement; and means for forming a relatively low-pressure air barrier in the region of adjacency of the barrier member and said surface to inhibit wetting of said trailing portion of said member by said developer liquid, said air barrier forming means comprising means for forming a transverse slit in said barrier member between said leading and trailing portions and means for maintaining the interior of said slit at a pressure greater than atmospheric pressure, said pressure maintaining means supplying the interior of said slit with air at a rate between 2 and 4 cubic feet per minute.

Claim 28

Apparatus for removing excess developer liquid from an image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a mechanical barrier member extending across said surface; means mounting said member in spaced relationship to said surface with a spacing between said barrier member and said surface which is less than said certain thickness, said mounting means comprising a pair of rollers rotatably attached to the barrier member at opposite ends thereof and means for biasing the rollers against the image-bearing surface; means for moving said surface and said barrier member relative to each other whereby said barrier member has a trailing portion with reference to the direction of said relative movement; and means for forming a relatively low-pressure air barrier in the region of adjacency of the barrier member and said surface to inhibit wetting of said trailing portion of said barrier member by said developer liquid.

Claim 29

Apparatus for removing excess developer liquid from an image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a mechanical barrier member extending across said surface; means mounting said member in spaced relationship to said surface with a spacing between said barrier member and said surface which is less than said certain thickness, said mounting means comprising a pair of rollers rotatably attached to the barrier member at opposite ends thereof and means for biasing the rollers against the image-bearing surface; means for moving said surface and said barrier member relative to each other whereby said barrier member has a trailing portion with reference to the direction of said relative movement; and means for forming a relatively low-pressure air barrier in the region of adjacency of the barrier member and said surface to inhibit wetting of said trailing portion of said barrier member by said developer liquid.

Claim 30

Apparatus for removing excess developer liquid from a moving image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: an elongated barrier member; means for mounting said barrier member with the length thereof extending across the portion of said surface bearing said image and with a spacing between the leading portion of said barrier member and said surface which is between 0.001 and 0.002 inch; and means for forming an air curtain behind the leading portion of said barrier member, the region adjacent to said developer layer and the leading portion of said barrier member being substantially unpressurized to permit relatively unrestricted flow of air toward the leading portion of said barrier member.

Claim 31

Apparatus for removing excess developer liquid from a moving image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: an elongated barrier member; means for mounting said barrier member with the length thereof extending across the portion of said surface bearing said image and with a spacing between the leading portion of said barrier member and said surface which is between 0.001 and 0.002 inch; and means for forming an air curtain behind the leading portion of said barrier member, the region adjacent to said developer layer and the leading portion of said barrier member being substantially unpressurized to permit relatively unrestricted flow of air toward the leading portion of said barrier member.

Claim 32

Apparatus for removing excess developer liquid from a moving image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a generally cylindrical member having a hollow interior and an axially extending exit slit communicating with said interior and having an axially extending groove formed in the outer surface along each side of the exit slit; means for mounting said member with the length thereof extending across the portion of said surface bearing said image and with a spacing between said exit slit and said surface which is less than the thickness of said developer layer to intercept said layer; and means for maintaining said interior at a pressure greater than atmospheric pressure to form an air curtain behind the leading portion of said member, the region adjacent to said developer layer and the leading portion of said member being substantially unpressurized to permit relatively unrestricted flow of air from said exit slit toward the leading portion of said member.

Claim 33

Apparatus for removing excess developer liquid from a moving image-bearing surface carrying a layer of liquid developer of a certain thickness including, in combination: a generally cylindrical member having a hollow interior and an axially extending exit slit communicating with said interior and having an axially extending groove formed in the outer surface along each side of the exit slit; means for mounting said member with the length thereof extending across the portion of said surface bearing said image and with a spacing between said exit slit and said surface which is less than the thickness of said developer layer to intercept said layer; and means for maintaining said interior at a pressure greater than atmospheric pressure to form an air curtain behind the leading portion of said member, the region adjacent to said developer layer and the leading portion of said member being substantially unpressurized to permit relatively unrestricted flow of air from said exit slit toward the leading portion of said member.

Claim 34

Apparatus as in claim 18, further including a second edge spaced behind said first edge, said air curtain means creating a pressurized region between said first edge and said second edge.

Claim 35

Apparatus as in claim 18 in which said developer layer is directly exposed to the ambient atmosphere in the region immediately in advance of the leading portion of said edge.

Claim 36

Apparatus as in claim 18 in which said first edge has a substantially unpressurized region immediately in advance of the leading portion thereof and adjacent to the developer layer.