US5307122A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming apparatus apparatus unit facsimile apparatus and developer comprising hydrophobic silica fine powder for developing electrostatic images
Assignee: Canon Inc
•
Filing: 1990-07-26
•
Granted: 1994-04-26
•
Expires: 2010-07-26
Abstract
Abstract An image forming apparatus includes a member to be charged for carrying an electrostatic image, a contact-charging means for charging the member to be charged in contact with the member to be charged, and a developing means for developing the electrostatic image carried on the member to be charged. The developing means includes a developer for developing the electrostatic image comprising a toner and hydrophobic inorganic fine powder. The hydrophobic inorganic fine powder not only improves the fluidity of the developer and adjusts the chargeability of the developer but also prevents difficulties due to interaction between the member to be charged and the contact charging means in the presence of residual developer, such as damages of the member to be charged and toner-sticking onto the member to be charged.
Inventors
- 👤 Manabu Ohno
- 👤 Hisayuki Ochi
- 👤 Tetsuhito Kuwashima
- 👤 Hiroyuki Suematsu
- 👤 Eiichi Imai
- 👤 Tsuyoshi Takiguchi
- 👤 Koichi Tomiyama
- 👤 Tsutomu Kukimoto
- 👤 Hiroshi Yusa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:43
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/0819; G03G13/00; G03G13/02; G03G13/025; G03G13/06; G03G13/08; G03G13/09; G03G9/0821; G03G9/083; G03G9/0836; G03G9/087; G03G9/08702; G03G9/08726; G03G9/08733; G03G9/08784; G03G9/08791; G03G9/097; G03G9/09708; G03G9/09716; G03G2215/00; G03G2215/02; G03G2215/021; G03G2221/00; G03G2221/16; G03G2221/18; G03G2221/183; G03G9/08795
Claims Analysis
Total Claims: 78
Claim 1
Independent Claim
124 words
An image forming apparatus, comprising: a member to be charged for carrying an electrostatic image, a contact-charging means for charging the member to be charged in contact with the member to be charged, and a developing means for developing the electrostatic image carried on the member to be charged, wherein the developing means includes a developer for developing the electrostatic image comprising a toner and hydrophobic inorganic fine powder, wherein said toner comprises a binder resin composition which contains 10-70 wt. % of a THF (tetrahydrofuran)-insoluble content and the remainder of a THF-soluble content including a component with a molecular weight of 10,000 or below on a GPC (gel permeation chromatography) chromatogram of the THF-soluble content constituting 10-50 wt. % of the binder resin.
Claim 2
Dependent Claim
124 words
An image forming apparatus, comprising: a member to be charged for carrying an electrostatic image, a contact-charging means for charging the member to be charged in contact with the member to be charged, and a developing means for developing the electrostatic image carried on the member to be charged, wherein the developing means includes a developer for developing the electrostatic image comprising a toner and hydrophobic inorganic fine powder, wherein said toner comprises a binder resin composition which contains 10-70 wt. % of a THF (tetrahydrofuran)-insoluble content and the remainder of a THF-soluble content including a component with a molecular weight of 10,000 or below on a GPC (gel permeation chromatography) chromatogram of the THF-soluble content constituting 10-50 wt. % of the binder resin.
Claim 3
Dependent Claim
16 words
The apparatus according to claim 1, wherein said member to be charged comprises a photosensitive member.
Claim 4
Dependent Claim
20 words
The apparatus according to claim 1, wherein said member to be charged comprises a lamination-type OPC organic photoconductor photosensitive member.
Claim 5
Dependent Claim
25 words
The apparatus according to claim 1, wherein said contact charging means is abutted to the member to be charged at a pressure of 5-500 g/cm.
Claim 6
Dependent Claim
18 words
The apparatus according to claim 1, wherein said hydrophobic inorganic fine powder comprises hydrophobic metal oxide fine powder.
Claim 7
Dependent Claim
17 words
The apparatus according to claim 1, wherein said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder.
Claim 8
Dependent Claim
63 words
The apparatus according to claim 1, wherein said member to be charged comprises a lamination-type OPC photosensitive member, said contact-charging means is in the form of a roller having an electroconductive rubber layer and a releasable coating, said toner comprises negatively chargeable magnetic toner particles, and said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder treated with silicone oil or silicone varnish.
Claim 9
Dependent Claim
65 words
The apparatus according to claim 1, wherein said member to be charged comprises a lamination-type OPC photosensitive member, said contact-charging means is in the form of a roller having an electroconductive rubber layer and a releasable coating, said toner comprises positively chargeable magnetic toner particles, and said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder treated with amino-modified silicone oil or amino-modified silicone varnish.
Claim 10
Dependent Claim
24 words
The apparatus according to claim 1, wherein said contact-charging means has a voltage application means for applying an AC voltage or/and a DC voltage.
Claim 11
Dependent Claim
35 words
The apparatus according to claim 1, wherein said contact-charging means comprises a voltage application means for applying an AC voltage of 0.5-5 kVpp and 50-300 Hz and a DC voltage (absolute value) of 200-900 V.
Claim 12
Dependent Claim
18 words
The apparatus according to claim 1, wherein said developing means comprises a developing sleeve for carrying the developer.
Claim 13
Dependent Claim
23 words
The apparatus according to claim 1, wherein said member to be charged comprises a lamination-type OPC photosensitive member and has a cleaning means.
Claim 14
Dependent Claim
14 words
The apparatus according to claim 12, wherein said cleaning means comprises a cleaning blade.
Claim 15
Dependent Claim
27 words
The apparatus according to claim 7, wherein said electroconductive rubber layer has a thickness of 0.1-10 mm, and said releasable coating has a thickness of 5-30 microns.
Claim 16
Dependent Claim
23 words
The apparatus according to claim 7, wherein said electroconductive rubber layer comprises an ethylene-propylene-diene terpolymer, and said releasable coating comprises a nylon resin.
Claim 17
Dependent Claim
44 words
The apparatus according to claim 7, wherein said lamination-type OPC photosensitive member is surfaced with a material selected from the group consisting of silicone resins, vinylidene chloride resins, ethylene-vinyl chloride resin, styrene-acrylonitrile resin, styrene-methyl methacrylate resin, styrene resins, polyethylene terephthalate resins and polycarbonate resins.
Claim 18
Dependent Claim
16 words
The apparatus according to claim 7, wherein said lamination-type OPC photosensitive member is surfaced with polycarbonate.
Claim 19
Dependent Claim
17 words
The apparatus according to claim 1, wherein said binder resin composition comprises a vinyl polymer or copolymer.
Claim 20
Dependent Claim
17 words
The apparatus according to claim 1, wherein said binder resin composition comprises a styrene polymer or copolymer.
Claim 21
Dependent Claim
32 words
The apparatus according to claim 1, wherein said toner comprises magnetic toner particles and the magnetic toner particles contain a magnetic material having a bulk density of 0.35 g/cm 3 or higher.
Claim 22
Dependent Claim
32 words
The apparatus according to claim 1, wherein said toner comprises magnetic toner particles and the magnetic toner particles contain a magnetic material having a bulk density of 0.5 g/cm 3 or higher.
Claim 23
Dependent Claim
127 words
The apparatus according to claim 1, wherein said developer comprises a magnetic toner having a volume-average particle size of 4-8 microns and hydrophobic inorganic fine powder treated with silicone oil or silicone varnish, 100 wt. parts of the developer contains 0.2-2.0 wt. parts of the hydrophobic inorganic fine powder, and the magnetic toner contains a binder resin which comprises 3-20 wt. parts of polymerized units of a monomer having an acid group formed of a carboxyl group or its anhydride per 100 wt. parts of the binder resin and has an acid value of 1-70, and the developer has a BET specific surface area of 1.8-3.5 m 2 /g, a loose apparent density of 0.4-0.52 g/cm 3 , and a true density of 1.45-1.8 g/cm 3 .
Claim 24
Dependent Claim
25 words
The apparatus according to claim 22, wherein 0.6-1.6 wt. parts of the hydrophobic inorganic fine powder is contained in 100 wt. parts of the developer.
Claim 25
Dependent Claim
123 words
The apparatus according to claim 1 wherein said toner comprises a magnetic toner having a volume-average particle size of 4-8 microns, and a particle size distribution including 17-60% by number of magnetic toner particles of 5 microns or smaller, 5-50% by number of magnetic toner particles of 6.35-10.08 microns and 2.0 volume % or less of magnetic toner particles of 12.7 microns or larger and further satisfies the following equation: N/V=-0.06N+k, wherein N denotes the contents in % by number of the magnetic toner particles of 5 microns or smaller, V denotes the content in % by volume of the magnetic toner particles of 5 microns or smaller, k is a positive number of 4.6-6.7, and N is a positive number of 17-60.
Claim 26
Dependent Claim
33 words
The apparatus according to claim 1, wherein said hydrophobic inorganic fine powder has been treated with a silane coupling agent and then with silicon oil, silicone-varnish, amino-modified silicone oil or amino-modified silicone varnish.
Claim 27
Independent Claim
163 words
An apparatus unit, comprising: a member to be charged for carrying an electrostatic image, a contact-charging means for charging the member to be charged in contact with the member to be charged, and a developing means for developing the electrostatic image carried on the member to be charged, wherein the developing means includes a developer for developing the electrostatic image comprising a toner and hydrophobic inorganic fine powder; wherein at least one of said contact-charging means and developing means is supported integrally together with said member to be charged to form a single unit, which can be connected to or released from an apparatus body as desired; and wherein said toner comprises a binder resin composition which contains 10-70 wt. % of a THF (tetrahydrofuran)-insoluble content and the remainder of a THF-soluble content including a component with a molecular weight of 10,000 or below on a GPC (gel permeation chromatography) chromatogram of the THF-soluble content constituting 10-50 wt. % of the binder resin.
Claim 28
Independent Claim
163 words
An apparatus unit, comprising: a member to be charged for carrying an electrostatic image, a contact-charging means for charging the member to be charged in contact with the member to be charged, and a developing means for developing the electrostatic image carried on the member to be charged, wherein the developing means includes a developer for developing the electrostatic image comprising a toner and hydrophobic inorganic fine powder; wherein at least one of said contact-charging means and developing means is supported integrally together with said member to be charged to form a single unit, which can be connected to or released from an apparatus body as desired; and wherein said toner comprises a binder resin composition which contains 10-70 wt. % of a THF (tetrahydrofuran)-insoluble content and the remainder of a THF-soluble content including a component with a molecular weight of 10,000 or below on a GPC (gel permeation chromatography) chromatogram of the THF-soluble content constituting 10-50 wt. % of the binder resin.
Claim 29
Dependent Claim
17 words
The apparatus unit according to claim 26, wherein said member to be charged comprises a photosensitive member.
Claim 30
Dependent Claim
21 words
The apparatus unit according to claim 26, wherein said member to be charged comprises a lamination-type OPC organic photoconductor photosensitive member.
Claim 31
Dependent Claim
26 words
The apparatus unit according to claim 26, wherein said contact charging means is abutted to the member to be charged at a pressure of 5-500 g/cm.
Claim 32
Dependent Claim
19 words
The apparatus unit according to claim 26, wherein said hydrophobic inorganic fine powder comprises hydrophobic metal oxide fine powder.
Claim 33
Dependent Claim
18 words
The apparatus unit according to claim 26, wherein said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder.
Claim 34
Dependent Claim
64 words
The apparatus unit according to claim 26, wherein said member to be charged comprises a lamination-type OPC photosensitive member, said contact-charging means is in the form of a roller having an electroconductive rubber layer and a releasable coating, said toner comprises negatively chargeable magnetic toner particles, and said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder treated with silicone oil or silicone varnish.
Claim 35
Dependent Claim
66 words
The apparatus unit according to claim 26, wherein said member to be charged comprises a lamination-type OPC photosensitive member, said contact-charging means is in the form of a roller having an electroconductive rubber layer and a releasable coating, said toner comprises positively chargeable magnetic toner particles, and said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder treated with amino-modified silicone oil or amino-modified silicone varnish.
Claim 36
Dependent Claim
25 words
The apparatus unit according to claim 26, wherein said contact-charging means has a voltage application means for applying an AC voltage or/and a DC voltage.
Claim 37
Dependent Claim
36 words
The apparatus unit according to claim 26, wherein said contact-charging means comprises a voltage application means for applying an AC voltage of 0.5-5 kVpp and 50-300 Hz and a DC voltage (absolute value) of 200-900 V.
Claim 38
Dependent Claim
19 words
The apparatus unit according to claim 26, wherein said developing means comprises a developing sleeve for carrying the developer.
Claim 39
Dependent Claim
24 words
The apparatus unit according to claim 26, wherein said member to be charged comprises a lamination-type OPC photosensitive member and has a cleaning means.
Claim 40
Dependent Claim
15 words
The apparatus unit according to claim 37, wherein said cleaning means comprises a cleaning blade.
Claim 41
Dependent Claim
28 words
The apparatus unit according to claim 32, wherein said electroconductive rubber layer has a thickness of 0.1-10 mm, and said releasable coating has a thickness of 5-30 microns.
Claim 42
Dependent Claim
24 words
The apparatus unit according to claim 32, wherein said electroconductive rubber layer comprises an ethylene-propylene-diene terpolymer, and said releasable coating comprises a nylon resin.
Claim 43
Dependent Claim
45 words
The apparatus unit according to claim 32, wherein said lamination-type OPC photosensitive member is surfaced with a material selected from the group consisting of silicone resins, vinylidene chloride resins, ethylene-vinyl chloride resin, styrene-acrylonitrile resin, styrene-methyl methacrylate resin, styrene resins, polyethylene terephthalate resins and polycarbonate resins.
Claim 44
Dependent Claim
17 words
The apparatus unit according to claim 32, wherein said lamination-type OPC photosensitive member is surfaced with polycarbonate.
Claim 45
Dependent Claim
18 words
The apparatus unit according to claim 26, wherein said binder resin composition comprises a vinyl polymer or copolymer.
Claim 46
Dependent Claim
18 words
The apparatus unit according to claim 26, wherein said binder resin composition comprises a styrene polymer or copolymer.
Claim 47
Dependent Claim
33 words
The apparatus unit according to claim 26, wherein said toner comprises magnetic toner particles and the magnetic toner particles contain a magnetic material having a bulk density of 0.35 g/cm 3 or higher.
Claim 48
Dependent Claim
33 words
The apparatus unit according to claim 26, wherein said toner comprises magnetic toner particles and the magnetic toner particles contain a magnetic material having a bulk density of 0.5 g/cm 3 or higher.
Claim 49
Dependent Claim
127 words
The apparatus according to claim 26, wherein said developer comprises a magnetic toner having a volume-average particle size of 4-8 microns and hydrophobic inorganic fine powder treated with silicone oil or silicone varnish, 100 wt. parts of the developer contains 0.2-2.0 wt. parts of the hydrophobic inorganic fine powder, and the magnetic toner contains a binder resin which comprises 3-20 wt. parts of polymerized units of a monomer having an acid group formed of a carboxyl group or its anhydride per 100 wt. parts of the binder resin and has an acid value of 1-70, and the developer has a BET specific surface area of 1.8-3.5 m 2 /g, a loose apparent density of 0.4-0.52 g/cm 3 , and a true density of 1.45-1.8 g/cm 3 .
Claim 50
Dependent Claim
26 words
The apparatus unit according to claim 47, wherein 0.6-1.6 wt. parts of the hydrophobic inorganic fine powder is contained in 100 wt. parts of the developer.
Claim 51
Dependent Claim
124 words
The apparatus unit according to claim 26 wherein said toner comprises a magnetic toner having a volume-average particle size of 4-8 microns, and a particle size distribution including 17-60% by number of magnetic toner particles of 5 microns or smaller, 5-50% by number of magnetic toner particles of 6.35-10.08 microns and 2.0 volume % or less of magnetic toner particles of 12.7 microns or larger and further satisfies the following equation: N/V=-0.05N+k, wherein N denotes the contents in % by number of the magnetic toner particles of 5 microns or smaller, V denotes the content in % by volume of the magnetic toner particles of 5 microns or smaller, k is a positive number of 4.6-6.7, and N is a positive number of 17-60.
Claim 52
Dependent Claim
35 words
The apparatus unit according to claim 26 wherein said hydrophobic inorganic fine powder has been treated with a silane coupling agent and then with silicon oil, silicone varnish, amino-modified silicone oil or amino-modified silicone varnish.
Claim 53
Dependent Claim
143 words
An facsimile apparatus, comprising: an electrophotographic apparatus and a receiving means for receiving image data from a remote terminal, wherein said electrophotographic apparatus comprises: a member to be charged for carrying an electrostatic image, a contact-charging means for charging the member to be charged in contact with the member to be charged, and a developing means for developing the electrostatic image carried on the member to be charged, wherein the developing means includes a developer for developing the electrostatic image comprising a toner and hydrophobic inorganic fine powder, wherein said toner comprises a binder resin composition which contains 10-70 wt. % of a THF (tetrahydrofuran)-insoluble content and the remainder of a THF-soluble content including a component with a molecular weight of 10,000 or below on a GPC (gel permeation chromatography) chromatogram of the THF-soluble content constituting 10-50 wt. % of the binder resin.
Claim 54
Dependent Claim
143 words
An facsimile apparatus, comprising: an electrophotographic apparatus and a receiving means for receiving image data from a remote terminal, wherein said electrophotographic apparatus comprises: a member to be charged for carrying an electrostatic image, a contact-charging means for charging the member to be charged in contact with the member to be charged, and a developing means for developing the electrostatic image carried on the member to be charged, wherein the developing means includes a developer for developing the electrostatic image comprising a toner and hydrophobic inorganic fine powder, wherein said toner comprises a binder resin composition which contains 10-70 wt. % of a THF (tetrahydrofuran)-insoluble content and the remainder of a THF-soluble content including a component with a molecular weight of 10,000 or below on a GPC (gel permeation chromatography) chromatogram of the THF-soluble content constituting 10-50 wt. % of the binder resin.
Claim 55
Dependent Claim
17 words
The facsimile apparatus according to claim 51, wherein said member to be charged comprises a photosensitive member.
Claim 56
Dependent Claim
21 words
The facsimile apparatus according to claim 51, wherein said member to be charged comprises a lamination-type OPC organic photoconductor photosensitive member.
Claim 57
Dependent Claim
26 words
The facsimile apparatus according to claim 51, wherein said contact charging means is abutted to the member to be charged at a pressure of 5-500 g/cm.
Claim 58
Dependent Claim
19 words
The facsimile apparatus according to claim 51, wherein said hydrophobic inorganic fine powder comprises hydrophobic metal oxide fine powder.
Claim 59
Dependent Claim
18 words
The facsimile apparatus according to claim 51, wherein said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder.
Claim 60
Dependent Claim
64 words
The facsimile apparatus according to claim 51, wherein said member to be charged comprises a lamination-type OPC photosensitive member, said contact-charging means is in the form of a roller having an electroconductive rubber layer and a releasable coating, said toner comprises negatively chargeable magnetic toner particles, and said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder treated with silicone oil or silicone varnish.
Claim 61
Dependent Claim
66 words
The facsimile apparatus according to claim 51, wherein said member to be charged comprises a lamination-type OPC photosensitive member, said contact-charging means is in the form of a roller having an electroconductive rubber layer and a releasable coating, said toner comprises positively chargeable magnetic toner particles, and said hydrophobic inorganic fine powder comprises hydrophobic silica fine powder treated with amino-modified silicone oil or amino-modified silicone varnish.
Claim 62
Dependent Claim
25 words
The facsimile apparatus according to claim 51, wherein said contact-charging means has a voltage application means for applying an AC voltage or/and a DC voltage.
Claim 63
Dependent Claim
36 words
The facsimile apparatus according to claim 51, wherein said contact-charging means comprises a voltage application means for applying an AC voltage of 0.5-5 kVpp and 50-300 Hz and a DC voltage absolute value of 200-900 V.
Claim 64
Dependent Claim
19 words
The facsimile apparatus according to claim 51, wherein said developing means comprises a developing sleeve for carrying the developer.
Claim 65
Dependent Claim
24 words
The facsimile apparatus according to claim 51, wherein said member to be charged comprises a lamination-type OPC photosensitive member and has a cleaning means.
Claim 66
Dependent Claim
15 words
The facsimile apparatus according to claim 62, wherein said cleaning means comprises a cleaning blade.
Claim 67
Dependent Claim
28 words
The facsimile apparatus according to claim 57, wherein said electroconductive rubber layer has a thickness of 0.1-10 mm, and said releasable coating has a thickness of 5-30 microns.
Claim 68
Dependent Claim
24 words
The facsimile apparatus according to claim 57, wherein said electroconductive rubber layer comprises an ethylene-propylene-diene terpolymer, and said releasable coating comprises a nylon resin.
Claim 69
Dependent Claim
45 words
The facsimile apparatus according to claim 57, wherein said lamination-type OPC photosensitive member is surfaced with a material selected from the group consisting of silicone resins, vinylidene chloride resins, ethylene-vinyl chloride resin, styrene-acrylonitrile resin, styrene-methyl methacrylate resin, styrene resins, polyethylene terephthalate resins and polycarbonate resins.
Claim 70
Dependent Claim
17 words
The facsimile apparatus according to claim 57, wherein said lamination-type OPC photosensitive member is surfaced with polycarbonate.
Claim 71
Dependent Claim
18 words
The facsimile apparatus according to claim 51, wherein said binder resin composition comprises a vinyl polymer or copolymer.
Claim 72
Dependent Claim
18 words
The facsimile apparatus according to claim 51, wherein said binder resin composition comprises a styrene polymer or copolymer.
Claim 73
Dependent Claim
33 words
The facsimile apparatus according to claim 51, wherein said toner comprises magnetic toner particles and the magnetic toner particles contain a magnetic material having a bulk density of 0.5 g/cm 3 or higher.
Claim 74
Dependent Claim
33 words
The facsimile apparatus according to claim 51, wherein said toner comprises magnetic toner particles and the magnetic toner particles contain a magnetic material having a bulk density of 0.35 g/cm 3 or higher.
Claim 75
Dependent Claim
129 words
The facsimile apparatus according to claim 51, wherein said developer comprises a magnetic toner having a volume-average particle size of 4-8 microns and hydrophobic inorganic fine powder treated with silicone oil or silicone varnish, 100 wt. parts of the developer contains 0.2-2.0 wt. parts of the hydrophobic inorganic fine powder, and the magnetic toner contains a binder resin which comprises 3- 20 wt. parts of polymerized units of a monomer having an acid group formed of a carboxyl group or its anhydride per 100 wt. parts of the binder resin and has an acid value of 1-70, and the developer has a BET specific surface area of 1.8-3.5 m 2 /g, a loose apparent density of 0.4-0.52 g/cm 3 , and a true density of 1.45-1.8 g/cm 3 .
Claim 76
Dependent Claim
26 words
The facsimile apparatus according to claim 72, wherein 0.6-1.6 wt. parts of the hydrophobic inorganic fine powder is contained in 100 wt. parts of the developer.
Claim 77
Dependent Claim
124 words
The facsimile apparatus according to claim 51, wherein said toner comprises a magnetic toner having a volume-average particle size of 4-8 microns, and a particle size distribution including 17-60% by number of magnetic toner particles of 5 microns or smaller, 5-50% by number of magnetic toner particles of 6.35-10.08 microns and 2.0 volume % or less of magnetic toner particles of 12.7 microns or larger and further satisfies the following equation: N/V=-0.05N+k, wherein N denotes the contents in % by number of the magnetic toner particles of 5 microns or smaller, V denotes the content in % by volume of the magnetic toner particles of 5 microns or smaller, k is a positive number of 4.6-6.7, and N is a positive number of 17-60.
Claim 78
Dependent Claim
35 words
The facsimile apparatus according to claim 51, wherein said hydrophobic inorganic fine powder has been treated with a silane coupling agent and then with silicon oil, silicone varnish, amino-modified silicone oil or amino-modified silicone varnish.
References Cited (Backward Citations)
JPS4847345A
Cited
JPS4847346A
Cited
JPS5013661A
Cited
JPS5442141A
Cited
JPS5518656A
Cited
US4414579A
Cited
US4400739A
Cited
US4470689A
Cited
US4680245A
Cited
JPS60186854A
Cited
US4702986A
Cited
US4740443A
Cited
US4663263A
Cited
US4741984A
Cited
US4737432A
Cited
US4797344A
Cited
US4868084A
Cited
US4906548A
Cited
EP0280542A2
Cited
US4849785A
Cited
US4980256A
Cited
US4754300A
Cited
US4959731A
Cited
US5006902A
Cited
US4959688A
Cited
JPH01112253A
Cited
US4967231A
Cited
US4939060A
Cited
EP0395026A2
Cited
US5055879A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-04-25 | 1997-10-25 | 1998-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-04-25 | 2001-10-25 | 2002-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-04-25 | 2005-10-25 | 2006-04-26 | $7700.00 | Window Closed / Lapsed |