US4025339A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic film, method of making the same and photoconductive coating used therewith
Assignee: Coulter Information Systems Inc
•
Filing: 1976-07-13
•
Granted: 1977-05-24
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Expires: 1996-07-13
Abstract
Abstract An electrophotographic film which is not only capable of being utilized for the same purposes as conventional xerographic and electrofax members but it also capable of being used in the same manner as silver halide emulsion photographic films, that is, with high speed cameras for universal photographic purposes. The electrophotographic film comprises a thin film coating of an inorganic, photoconductive, electronically anisotropic material one example of which is a specially sputtered cadmium sulfide bonded to a thin film layer of ohmic material which in turn is bonded to a thin, stable substrate member preferably formed of plastic sheeting. The total thickness of the photoconductive coating is about 3000 Angstroms, of the ohmic layer is about 500 Angstroms and of the substrate member is a fraction of a millimeter. The product is durable with a hard, abrasive-resistant surface, is highly transparent and flexible notwithstanding the fact that the photoconductive layer is crystalline, and has high photoelectric gain with sufficient speed and sensitivity to be used as mentioned in high speed photography. As such it can accept a charge at a rapid rate and will retain the same selectively after exposure to enable practical toning with an almost infinite gradation of pigment values, i.e., gray scale. The electrophotographic film which is made using the cadmium sulfide as the photoconductive coating has substantially panchromatic response. The photoconductive coating is novel and can be used in cases where its unusual characteristics provide functions other than required in the electrophotographic film. For example, the coating can be used in many places where it is not important that the entire assembly be transparent. It can be used on metal substrates in making economical circuit elements, for forming photosensitive devices, for making storage elements, in producing recording and transfer media and the like. Novel methods of manufacture and use of the electrophotographic film and the photoconductive coating are disclosed.
Inventors
- 👤 Manfred R. Kuehnle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:22
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/02; G03G5/04; G03G5/08; G03G5/082
Claims Analysis
Total Claims: 98
Claim 1
Independent Claim
137 words
In an electrophotographic article in which substrate means carry thin film coatings at least one of which is a thin film coating of a photoconductive material less than 1 micron in thickness, means contiguous to the coating to facilitate uniform charging thereof before exposure; the invention comprising, said coating being very dense, wholly inorganic, microcrystalline, the crystals of said coating being generally uniformly oriented vertically relative to the surface of the substrate means, substantially free of effective barrier layers between the crystals, the coating having light transmissivity of at least 70 percent, having a dark resistivity of at least 10 12 ohm-centimeters and a ratio between dark and light resistivity of at least about 10 4 and being electrically anisotropic whereby said coating is capable of accepting a rapid charge and retaining same sufficient to enable toning.
Claim 2
Dependent Claim
137 words
In an electrophotographic article in which substrate means carry thin film coatings at least one of which is a thin film coating of a photoconductive material less than 1 micron in thickness, means contiguous to the coating to facilitate uniform charging thereof before exposure; the invention comprising, said coating being very dense, wholly inorganic, microcrystalline, the crystals of said coating being generally uniformly oriented vertically relative to the surface of the substrate means, substantially free of effective barrier layers between the crystals, the coating having light transmissivity of at least 70 percent, having a dark resistivity of at least 10 12 ohm-centimeters and a ratio between dark and light resistivity of at least about 10 4 and being electrically anisotropic whereby said coating is capable of accepting a rapid charge and retaining same sufficient to enable toning.
Claim 3
Dependent Claim
14 words
The article as claimed in claim 1 in which said substrate means are transparent.
Claim 4
Dependent Claim
33 words
The article as claimed in claim 1 in which the means to facilitate uniform charging of the coating comprise a thin film layer of ohmic material sandwiched between the coating and substrate means.
Claim 5
Dependent Claim
22 words
The article as claimed in claim 1 in which said substrate means, the coating and the means to facilitate charging are flexible.
Claim 6
Dependent Claim
59 words
The article as claimed in claim 1 in which said substrate means comprise a transparent member; in which said thin film coating material is a semiconductor and is characterized by no greater than 85 percent light transmission; and in which the means to facilitate charging comprise a thin layer of ohmic material between said substrate means and said coating.
Claim 7
Dependent Claim
73 words
The article as claimed in claim 1 in which said substrate means comprise a flexible, transparent, organic polymer sheeting member; in which the light transmissivity of the coating is no greater than 85 percent, in which said coating is a semiconductor and flexible; and in which the means to facilitate charging comprise a thin layer of ohmic material between said substrate means and said thin film coating, said thin layer also being flexible.
Claim 8
Dependent Claim
18 words
An article as claimed in claim 1 in which said thin film coating material is dominantly cadmium sulfide.
Claim 9
Dependent Claim
18 words
An article as claimed in claim 2 in which said thin film coating material is dominantly cadmium sulfide.
Claim 10
Dependent Claim
18 words
An article as claimed in claim 3 in which said thin film coating material is dominantly cadmium sulfide.
Claim 11
Dependent Claim
18 words
An article as claimed in claim 4 in which said thin film coating material is dominantly cadmium sulfide.
Claim 12
Dependent Claim
18 words
An article as claimed in claim 5 in which said thin film coating material is dominantly cadmium sulfide.
Claim 13
Dependent Claim
13 words
An article as claimed in claim 5 in which the semiconductor is n-type.
Claim 14
Dependent Claim
13 words
An article as claimed in claim 6 in which the semiconductor is n-type.
Claim 15
Dependent Claim
25 words
An article as claimed in claim 3 in which said thin-film coating and said thin film layer are together less than around 5000 Angstroms thick.
Claim 16
Dependent Claim
26 words
An article as claimed in claim 5 in which said thin film coating and said thin film layer are together less than around 5000 Angstroms thick.
Claim 17
Dependent Claim
26 words
An article as claimed in claim 6 in which said thin film coating and said thin film layer are together less than around 5000 Angstroms thick.
Claim 18
Dependent Claim
20 words
An article as claimed in claim 1 in which said thin film coating is at least primarily zinc indium sulfide.
Claim 19
Dependent Claim
20 words
An article as claimed in claim 2 in which said thin film coating is at least primarily zinc indium sulfide.
Claim 20
Dependent Claim
20 words
An article as claimed in claim 3 in which said thin film coating is at least primarily zinc indium sulfide.
Claim 21
Dependent Claim
18 words
An article as claimed in claim 4 in which said thin film coating is dominantly zinc indium sulfide.
Claim 22
Dependent Claim
18 words
An article as claimed in claim 5 in which said thin film coating is dominantly zinc indium sulfide.
Claim 23
Dependent Claim
18 words
An article as claimed in claim 6 in which said thin film coating is dominantly zinc indium sulfide.
Claim 24
Dependent Claim
19 words
An article as claimed in claim 1 in which the said thin film coating is doped with a dopant.
Claim 25
Dependent Claim
19 words
An article as claimed in claim 2 in which the said thin film coating is doped with a dopant.
Claim 26
Dependent Claim
19 words
An article as claimed in claim 3 in which the said thin film coating is doped with a dopant.
Claim 27
Dependent Claim
17 words
An article as claimed in claim 1 in which said thin film coating is doped with copper.
Claim 28
Dependent Claim
16 words
An article as claimed in claim 2 in which said film coating is doped with copper.
Claim 29
Dependent Claim
17 words
An article as claimed in claim 3 in which said thin film coating is doped with copper.
Claim 30
Dependent Claim
18 words
An article as claimed in claim 1 in which the said thin film coating is doped with iodine.
Claim 31
Dependent Claim
18 words
An article as claimed in claim 2 in which the said thin film coating is doped with iodine.
Claim 32
Dependent Claim
18 words
An article as claimed in claim 3 in which the said thin film coating is doped with iodine.
Claim 33
Dependent Claim
28 words
An article as claimed in claim 3 in which said thin film coating is about 3000 Angstroms thick and said film layer is less than 1000 Angstroms thick.
Claim 34
Dependent Claim
28 words
An article as claimed in claim 5 in which said thin film coating is about 3000 Angstroms thick and said thin film layer less than 1000 Angstroms thick.
Claim 35
Dependent Claim
28 words
An article as claimed in claim 6 in which said thin film coating is about 3000 Angstroms thick and said film layer is less than 1000 Angstroms thick.
Claim 36
Dependent Claim
19 words
An article as claimed in claim 3 in which said thin film layer is at least primarily indium oxide.
Claim 37
Dependent Claim
20 words
An article as claimed in claim 4 in which said means to facilitate charging are at least primarily indium oxide.
Claim 38
Dependent Claim
19 words
An article as claimed in claim 5 in which said thin film layer is at least primarily indium oxide.
Claim 39
Dependent Claim
19 words
An article as claimed in claim 6 in which said thin film layer is at least primarily indium oxide.
Claim 40
Dependent Claim
19 words
An article as claimed in claim 7 in which said thin film layer is at least primarily indium oxide.
Claim 41
Dependent Claim
19 words
An article as claimed in claim 8 in which said thin film layer is at least primarily indium oxide.
Claim 42
Dependent Claim
21 words
An article as claimed in claim 35 in which the thin film layer also includes a small amount of tin oxide.
Claim 43
Dependent Claim
21 words
An article as claimed in claim 36 in which the thin film layer also includes a small amount of tin oxide.
Claim 44
Dependent Claim
21 words
An article as claimed in claim 37 in which the thin film layer also includes a small amount of tin oxide.
Claim 45
Dependent Claim
21 words
An article as claimed in claim 38 in which the thin film layer also includes a small amount of tin oxide.
Claim 46
Dependent Claim
21 words
An article as claimed in claim 39 in which the thin film layer also includes a small amount of tin oxide.
Claim 47
Dependent Claim
21 words
An article as claimed in claim 40 in which the thin film layer also includes a small amount of tin oxide.
Claim 48
Dependent Claim
29 words
The article as claimed in claim 6 in which means are provided for increasing the bonding of said thin film layer and thin film coating to the substrate means.
Claim 49
Dependent Claim
35 words
The article as claimed in claim 47 in which said bond increasing means comprises a second thin film layer of a transparent wholly inorganic material between the first thin film layer and the substrate means.
Claim 50
Dependent Claim
32 words
The article as claimed in claim 48 in which the second thin film layer is a photoconductor and has a thickness that is a small fraction of the first thin film layer.
Claim 51
Dependent Claim
16 words
The article as claimed in claim 49 in which the thin film layers are cadmium sulfide.
Claim 52
Dependent Claim
127 words
In an electrophotographic member which includes a substantially transparent thin film coating of a sputtered semiconductor on a flexible substrate of insulative material with a thin film, flexible transparent ohmic layer sandwiched between the coating and substrate; the improvement comprising; said coating being wholly inorganic, microcrystalline, flexible, substantially transparent, having the crystals thereof oriented uniformly generally vertically relative to the surface of the substrate to which the coating is applied, substantially free of effective barrier layers between the crystals, the coating having a dark resistivity of at least 10 12 ohm-centimeters and a ratio of dark to light resistivities of at least 10 4 and being electrically anisotropic whereby to be capable of accepting a charge and retaining same to such a degree as to enable toning.
Claim 53
Dependent Claim
127 words
In an electrophotographic member which includes a substantially transparent thin film coating of a sputtered semiconductor on a flexible substrate of insulative material with a thin film, flexible transparent ohmic layer sandwiched between the coating and substrate; the improvement comprising; said coating being wholly inorganic, microcrystalline, flexible, substantially transparent, having the crystals thereof oriented uniformly generally vertically relative to the surface of the substrate to which the coating is applied, substantially free of effective barrier layers between the crystals, the coating having a dark resistivity of at least 10 12 ohm-centimeters and a ratio of dark to light resistivities of at least 10 4 and being electrically anisotropic whereby to be capable of accepting a charge and retaining same to such a degree as to enable toning.
Claim 54
Dependent Claim
48 words
The article as claimed in claim 51 in which there is a thin film bonding layer of substantially the same material as the thin film coating interposed between the ohmic layer and the substrate but having a thickness substantially less than either the coating or the ohmic layer.
Claim 55
Dependent Claim
26 words
The article as claimed in claim 51 in which means are provided to establish electrical contact from said ohmic layer to circuitry exterior of the article.
Claim 56
Dependent Claim
15 words
The article as claimed in claim 51 in which the ohmic layer is a semiconductor.
Claim 57
Dependent Claim
113 words
For use with electrophotographic members or the like, a thin film photoconductive coating r.f. sputter deposited upon a suitable substrate, said coating being wholly inorganic, microcrystalline in highly ordered uniform arrangement, oriented generally vertically relative to the surface of the substrate, substantialy free of effective barrier layers between the crystals, being an n-type semiconductor, being chemically stable and abrasion resistant, having high photoelectric gain, having uniform morphology and stoichiometry, being electrically anisotropic whereby it is capable of accepting and retaining a charge to a degree enabling toning, the dark resistivity of said coating being at least 10.sup. 12 ohm-centimeters and the ratio of dark to light resistivities being at least 10 4 .
Claim 58
Dependent Claim
113 words
For use with electrophotographic members or the like, a thin film photoconductive coating r.f. sputter deposited upon a suitable substrate, said coating being wholly inorganic, microcrystalline in highly ordered uniform arrangement, oriented generally vertically relative to the surface of the substrate, substantialy free of effective barrier layers between the crystals, being an n-type semiconductor, being chemically stable and abrasion resistant, having high photoelectric gain, having uniform morphology and stoichiometry, being electrically anisotropic whereby it is capable of accepting and retaining a charge to a degree enabling toning, the dark resistivity of said coating being at least 10.sup. 12 ohm-centimeters and the ratio of dark to light resistivities being at least 10 4 .
Claim 59
Dependent Claim
20 words
The photoconductive coating as claimed in claim 55 in which said coating has a transmissivity between 70 and 85 percent.
Claim 60
Dependent Claim
16 words
The photoconductive coating as claimed in claim 55 in which the photoconductive coating is substantially transparent.
Claim 61
Dependent Claim
14 words
The photoconductive coating as claimed in claim 55 in which the coating is flexible.
Claim 62
Dependent Claim
21 words
The photoconductive coating as claimed in claim 55 in which the coating is cadmium sulfide about 3000 to 5000 Angstroms thick.
Claim 63
Dependent Claim
20 words
The photoconductive coating as claimed in claim 55 in which the dark resistivity is substantially increased upon charging in darkness.
Claim 64
Dependent Claim
20 words
The photoconductive coating as claimed in claim 56 in which the dark resistivity is substantially increased upon charging in darkness.
Claim 65
Dependent Claim
20 words
The photoconductive coating as claimed in claim 58 in which the dark resistivity is substantially increased upon charging in darkness.
Claim 66
Dependent Claim
20 words
The photoconductive coating as claimed in claim 59 in which the dark resistivity is substantially increased upon charging in darkness.
Claim 67
Dependent Claim
17 words
The photoconductive coating as claimed in claim 59 in which the coating is doped with a dopant.
Claim 68
Dependent Claim
190 words
In an electrophotographic film structure which includes a substrate having a thin film ohmic layer bonded to a surface thereof and a wholly inorganic thin film photoconductive coating bonded to the ohmic layer and sandwiching the layer between the substrate and the coating, the improvement comprising a film structure having the following properties: A. physical--the coating is microcrystalline, oriented uniformly generally vertical to the surface to which bonded, is substantially free of effective barrier layers between the crystals, is substantially inert to humidity, temperature variations and most radiation; has indefinite shelf life; is highly abrasion resistant; is very dense; B. optical--the film structure has between 70 percent and about 85 percent light transmissivity; and when charged and exposed to a radiation pattern, has a broad generally unpeaked spectral response; and C. electrical--the coating is an n-type semiconductor; is electrically anisotropic; can accept and sustain a rapid charge at a tonable level to achieve toned resolution as great as 1000 lines/mm; has a surface resistivity of at least 10 12 ohm-centimeters; has a relatively low light resistivity permitting total light discharge with practically no residual charge; and has no persistent photoconductivity.
Claim 69
Dependent Claim
190 words
In an electrophotographic film structure which includes a substrate having a thin film ohmic layer bonded to a surface thereof and a wholly inorganic thin film photoconductive coating bonded to the ohmic layer and sandwiching the layer between the substrate and the coating, the improvement comprising a film structure having the following properties: A. physical--the coating is microcrystalline, oriented uniformly generally vertical to the surface to which bonded, is substantially free of effective barrier layers between the crystals, is substantially inert to humidity, temperature variations and most radiation; has indefinite shelf life; is highly abrasion resistant; is very dense; B. optical--the film structure has between 70 percent and about 85 percent light transmissivity; and when charged and exposed to a radiation pattern, has a broad generally unpeaked spectral response; and C. electrical--the coating is an n-type semiconductor; is electrically anisotropic; can accept and sustain a rapid charge at a tonable level to achieve toned resolution as great as 1000 lines/mm; has a surface resistivity of at least 10 12 ohm-centimeters; has a relatively low light resistivity permitting total light discharge with practically no residual charge; and has no persistent photoconductivity.
Claim 70
Dependent Claim
70 words
An electrophotographic film structure as claimed in claim 65 which has the following additional properties: A. physical--the substrate, layer and coating are flexible and capable of being rolled to a diameter of less than 1/2 inch without damage, the total thickness of the coating and layer is about 5000 A; and B. electrical--the coating has a speed of discharge during exposure comparable with that of high speed conventional photographic film.
Claim 71
Dependent Claim
14 words
The structure as claimed in claim 66 in which the coating is cadmium sulfide.
Claim 72
Dependent Claim
44 words
The structure as claimed in claim 65 in which there is a thin film bonding layer between the ohmic layer and the substrate member of substantially the same material as said coating and having a thickness substantially less than that of said ohmic layer.
Claim 73
Dependent Claim
44 words
The structure as claimed in claim 66 in which there is a thin film bonding layer between the ohmic layer and the substrate member of substantially the same material as said coating and having a thickness substantially less than that of said ohmic layer.
Claim 74
Dependent Claim
44 words
The structure as claimed in claim 67 in which there is a thin film bonding layer between the ohmic layer and the substrate member of substantially the same material as said coating and having a thickness substantially less than that of said ohmic layer.
Claim 75
Dependent Claim
14 words
The structure as claimed in claim 67 in which the layer is indium oxide.
Claim 76
Dependent Claim
24 words
The structure as claimed in claim 67 in which the layer is a combination of indium oxide with a lesser amount of tin oxide.
Claim 77
Dependent Claim
115 words
In an electrophotographic member of the type having a photoconductive coating which is initially uniformly charged and thereafter exposed to a pattern of nonuniform radiation providing photons for selective discharge of the uniform charge to provide a latent image of remaining charge corresponding to the pattern of the nonuniform radiation the improvement comprising: A. a substrate of insulating material B. a photoconductive coating carried as a deposit upon the substrate and characterized by the following properties: 1. made of wholly inorganic material, 2. r.f. cathodic sputtered 3. generally uniformly vertically oriented crystalline, 4. of a sufficient thickness to enable absorption of relatively few photons to be sufficient to provide total discharge of the exposed surface,
Claim 78
Dependent Claim
115 words
In an electrophotographic member of the type having a photoconductive coating which is initially uniformly charged and thereafter exposed to a pattern of nonuniform radiation providing photons for selective discharge of the uniform charge to provide a latent image of remaining charge corresponding to the pattern of the nonuniform radiation the improvement comprising: A. a substrate of insulating material B. a photoconductive coating carried as a deposit upon the substrate and characterized by the following properties: 1. made of wholly inorganic material, 2. r.f. cathodic sputtered 3. generally uniformly vertically oriented crystalline, 4. of a sufficient thickness to enable absorption of relatively few photons to be sufficient to provide total discharge of the exposed surface,
Claim 79
Dependent Claim
138 words
n-type, 6. providing a substantial number of recombination centers, 7. having a dark resistivity greater than 10 12 ohm-centimeters considered statically and substantially greater than 10 12 ohm-centimeters considered dynamically, 8. a ratio of dark to light resistivity of at least 10 4 , 9. chemically stable and abrasion resistant, 10. electrically anisotropic, 11. being capable of accepting and retaining a charge to a degree to enable it to be exposed and toned and 12. is substantially free of effective barrier layers between the crystals and C. means including a generally electrically conductive plane in association with the substrate to enable charging of the photoconductive coating by corona or the like, the combining centers being independent of the electrical plane such that said means to enable charging of said coating are neither used nor required during discharge thereof.
Claim 80
Dependent Claim
138 words
n-type, 6. providing a substantial number of recombination centers, 7. having a dark resistivity greater than 10 12 ohm-centimeters considered statically and substantially greater than 10 12 ohm-centimeters considered dynamically, 8. a ratio of dark to light resistivity of at least 10 4 , 9. chemically stable and abrasion resistant, 10. electrically anisotropic, 11. being capable of accepting and retaining a charge to a degree to enable it to be exposed and toned and 12. is substantially free of effective barrier layers between the crystals and C. means including a generally electrically conductive plane in association with the substrate to enable charging of the photoconductive coating by corona or the like, the combining centers being independent of the electrical plane such that said means to enable charging of said coating are neither used nor required during discharge thereof.
Claim 81
Dependent Claim
21 words
The electrophotographic member as claimed in claim 73 in which the electrical plane is located between the substrate and the coating.
Claim 82
Dependent Claim
37 words
The electrophotographic member as claimed in claim 73 in which the electrical plane comprises a layer of ohmic material sandwiched between the substrate and the coating, the layer and coating and substrate all being intimately bonded together.
Claim 83
Dependent Claim
21 words
The electrophotographic member as claimed in claim 75 in which the ohmic material is conductive in at least one transverse direction.
Claim 84
Independent Claim
197 words
A method for manufacturing an electrophotographic film article which comprises: depositing a thin film layer of ohmic material upon a flexible thin organic transparent substrate in thoroughly bonded condition and a thickness which renders said thin film layer substantially transparent and flexible and r.f. direct cathodic sputtering a thin, electrically anisotropic film coating less than one micron in thickness of a wholly inorganic photoconductor material upon said ohmic material in a generally uniformly vertically oriented microcrystalline, substantially free of effective barrier layers between the crystals, thoroughly bonded condition and a thickness which provides a gain of said photoconductor material which is hight and which is substantially transparent and flexible, the total thickness of said article having a light transmissivity of not less than 70 percent and not more than about 85 percent, in which the sputtering is carried out in a chamber having an anode and a cathodic target formed of the material to be sputtered under conditions producing the usual dark space at the target, connecting the cathodic target to the high side of an r.f. generator and maintaining the anode on the negative side of ground whereby to produce a second dark space during sputtering.
Claim 85
Independent Claim
197 words
A method for manufacturing an electrophotographic film article which comprises: depositing a thin film layer of ohmic material upon a flexible thin organic transparent substrate in thoroughly bonded condition and a thickness which renders said thin film layer substantially transparent and flexible and r.f. direct cathodic sputtering a thin, electrically anisotropic film coating less than one micron in thickness of a wholly inorganic photoconductor material upon said ohmic material in a generally uniformly vertically oriented microcrystalline, substantially free of effective barrier layers between the crystals, thoroughly bonded condition and a thickness which provides a gain of said photoconductor material which is hight and which is substantially transparent and flexible, the total thickness of said article having a light transmissivity of not less than 70 percent and not more than about 85 percent, in which the sputtering is carried out in a chamber having an anode and a cathodic target formed of the material to be sputtered under conditions producing the usual dark space at the target, connecting the cathodic target to the high side of an r.f. generator and maintaining the anode on the negative side of ground whereby to produce a second dark space during sputtering.
Claim 86
Dependent Claim
24 words
The method as claimed in claim 77 in which the photoconductor material is doped during deposit by introducing a dopant into said r.f. field.
Claim 87
Dependent Claim
35 words
The method as claimed in claim 77 in which there is an extremely thin bonding layer of the same material as said coating is r.f. sputtered onto the substrate before the ohmic layer is deposited.
Claim 88
Dependent Claim
16 words
The method as claimed in claim 77 in which the ohmic layer is deposited by sputtering.
Claim 89
Dependent Claim
16 words
The method as claimed in claim 77 in which the ohmic layer is deposited by sputtering.
Claim 90
Dependent Claim
72 words
The method as claimed in claim 80 in which the sputtering is carried out in a chamber having an anode and a cathodic target formed of the material to be sputtered under conditions producing the usual dark space at the target, connecting the cathodic target to the high side of an r.f. generator and maintaining the anode on the negative side of ground whereby to produce a second dark space during sputtering.
Claim 91
Dependent Claim
150 words
In a method of manufacturing an article wich includes a substrate and a photoconductive coating bonded to the substrate, the step of depositing a thin film photoconductive coating on the substrate comprising the steps of establishing in a sputtering chamber a plasma between a cathodic target of photoconductive material to be sputtered and an anode carrying a substrate, connecting the cathodic target to the high negative side of the output of an r.f. generator and maintaining the anode below ground whereby to establish a Langmuir dark space between the plasma and the anode in addition to the ordinary dark space, and continuing the sputtering until a thin, electrically anisotropic film coating including said photoconductive material is coated upon a surface of said substrate in a uniformly ordered, microscrystalline layer with the crystals oriented uniformly generally vertically relative to said substrate surface, substantially free of effective barrier layers between the crystals.
Claim 92
Dependent Claim
150 words
In a method of manufacturing an article wich includes a substrate and a photoconductive coating bonded to the substrate, the step of depositing a thin film photoconductive coating on the substrate comprising the steps of establishing in a sputtering chamber a plasma between a cathodic target of photoconductive material to be sputtered and an anode carrying a substrate, connecting the cathodic target to the high negative side of the output of an r.f. generator and maintaining the anode below ground whereby to establish a Langmuir dark space between the plasma and the anode in addition to the ordinary dark space, and continuing the sputtering until a thin, electrically anisotropic film coating including said photoconductive material is coated upon a surface of said substrate in a uniformly ordered, microscrystalline layer with the crystals oriented uniformly generally vertically relative to said substrate surface, substantially free of effective barrier layers between the crystals.
Claim 93
Dependent Claim
13 words
The method as claimed in claim 83 in which the anode is heated.
Claim 94
Dependent Claim
15 words
The method as claimed in claim 83 in which the photoconductive material is cadmium sulfide.
Claim 95
Dependent Claim
24 words
The method as claimed in claim 85 in which hydrogen sulfide gas is introduced into the chamber as a background gas during the sputtering.
Claim 96
Independent Claim
346 words
A method for manufacturing an electrophotographic article that is capable of being charged and toned and which comprises: A. placing a substrate member having at least a surface that is conductive in an r.f. sputtering chamber in position to have the surface sputtered, the said surface being arranged to form substantially the anode in said chamber, B. positioning a target of a chemical compound formed of at least two inorganic elements and no organic elements in the chamber, the compound when sputtered producing a coating which is photoconductive in nature, C. connecting the target and anode in an r.f. sputtering circuit in which the target is effectively the cathode at a high negative voltage with respect to ground and the anode is negatively control-biased with respect to ground, D. sputtering in a non-reactive mode a coating of said compound onto the substrate to form a wholly inorganic photoconductive material on the substrate which is generally uniformly vertically oriented microcrystalline, substantially free of effective barrier layers between the crystals, electrically anisotropic, having a surface resistivity which is of the order of 10 12 ohm-centimeters in lateral directions when charged in darkness or discharged in light and also transversely of the coating in darkness, and which has a light resistivity transversely of the coating which is of the order of 10 8 ohm-centimeters or less, which is chemically stable and abrasion resistant and which is capable of accepting a charge and retaining it to a degree enabling the coating to be toned, E. the sputtering being carried on in an atmosphere that includes dominantly an inert but ionizable gas for forming a plasma between the target and substrate with a dark space at the target and the bias being such as to provide a second dark space at the substrate, with an additional background gas being introduced into the chamber along with the inert gas to prevent decomposition of the compound at the target or during deposition, and F. continuing the sputtering process until the thickness of the coating is at least sufficient to provide maximum photoconductive gain.
Claim 97
Independent Claim
346 words
A method for manufacturing an electrophotographic article that is capable of being charged and toned and which comprises: A. placing a substrate member having at least a surface that is conductive in an r.f. sputtering chamber in position to have the surface sputtered, the said surface being arranged to form substantially the anode in said chamber, B. positioning a target of a chemical compound formed of at least two inorganic elements and no organic elements in the chamber, the compound when sputtered producing a coating which is photoconductive in nature, C. connecting the target and anode in an r.f. sputtering circuit in which the target is effectively the cathode at a high negative voltage with respect to ground and the anode is negatively control-biased with respect to ground, D. sputtering in a non-reactive mode a coating of said compound onto the substrate to form a wholly inorganic photoconductive material on the substrate which is generally uniformly vertically oriented microcrystalline, substantially free of effective barrier layers between the crystals, electrically anisotropic, having a surface resistivity which is of the order of 10 12 ohm-centimeters in lateral directions when charged in darkness or discharged in light and also transversely of the coating in darkness, and which has a light resistivity transversely of the coating which is of the order of 10 8 ohm-centimeters or less, which is chemically stable and abrasion resistant and which is capable of accepting a charge and retaining it to a degree enabling the coating to be toned, E. the sputtering being carried on in an atmosphere that includes dominantly an inert but ionizable gas for forming a plasma between the target and substrate with a dark space at the target and the bias being such as to provide a second dark space at the substrate, with an additional background gas being introduced into the chamber along with the inert gas to prevent decomposition of the compound at the target or during deposition, and F. continuing the sputtering process until the thickness of the coating is at least sufficient to provide maximum photoconductive gain.
Claim 98
Dependent Claim
34 words
The method as claimed in claim 87 in which the compound is cadmium sulfide, the background gas is hydrogen sulfide and the bias voltage of the anode is substantially less than minus 200 volts.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-23 | 1980-11-22 | 1981-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-23 | 1984-11-22 | 1985-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-23 | 1988-11-22 | 1989-05-24 | $7700.00 | Window Closed / Lapsed |