US5485248A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming apparatus having a contact charger for varying a charge applied to a photosensitive drum based on a resistance of the photosensitive layer
Assignee: Canon Inc
•
Filing: 1995-01-12
•
Granted: 1996-01-16
•
Expires: 2015-01-12
Abstract
Abstract An image forming apparatus includes an image bearing member for bearing an image, a contact charger for charging the image bearing member, and a detector for detecting an electric current flowing through the charger when the charger changes a potential of a predetermined area of the image bearing member from a first potential to a second potential which is different from the first potential. In another aspect of the invention, the detector detects a flow of current through a second contact charger when a first oscillating voltage is applied by a first contact charger and a second oscillating voltage applied by the second contact charger which is different from the first oscillating voltage.
Inventors
- 👤 Hideyuki Yano
- 👤 Junji Araya
- 👤 Norio Hashimoto
- 👤 Harumi Kugoh
- 👤 Takashi Shibuya
- 👤 Tadashi Furuya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:04
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/75; G03G15/751; G03G15/02; G03G15/0208; G03G15/0216; G03G15/0291
Claims Analysis
Total Claims: 83
Claim 1
Independent Claim
119 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a charging member, contactable to said image bearing member, for charging said image bearing member; and detecting means for detecting an electric current flowing through said charging member at a time when a predetermined area of said image bearing member, which has been charged to a potential V1 by said charging member supplied with a first voltage, is charged to a potential V2 by said charging member supplied with a second voltage different from said first voltage; wherein, in the case an increase of electric current is detected, a decrease of a thickness of said image bearing layer can be determined.
Claim 2
Dependent Claim
119 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a charging member, contactable to said image bearing member, for charging said image bearing member; and detecting means for detecting an electric current flowing through said charging member at a time when a predetermined area of said image bearing member, which has been charged to a potential V1 by said charging member supplied with a first voltage, is charged to a potential V2 by said charging member supplied with a second voltage different from said first voltage; wherein, in the case an increase of electric current is detected, a decrease of a thickness of said image bearing layer can be determined.
Claim 3
Dependent Claim
21 words
An apparatus according to claim 1, further comprising display means for making a display when the current exceeds a predetermined range.
Claim 4
Dependent Claim
31 words
An apparatus according to claim 1, wherein said image bearing member is rotatable, and wherein said area of said image bearing member corresponds to one full-rotation of said image bearing member.
Claim 5
Dependent Claim
40 words
An apparatus according to claim 1, wherein when the potential V1 is provided, said charging member is provided with a first oscillating voltage, and when the potential V2 is provided, said charging member is supplied with a second oscillating voltage.
Claim 6
Dependent Claim
13 words
An apparatus according to claim 1, wherein the potential V1 is substantially 0.
Claim 7
Dependent Claim
25 words
An apparatus according to claim 4, wherein the potential V1 is substantially 0, and an oscillation center of the first oscillating voltage is substantially 0.
Claim 8
Dependent Claim
13 words
An apparatus according to claim 1, wherein the potential V2 is substantially 0.
Claim 9
Dependent Claim
25 words
An apparatus according to claim 4, wherein the potential V2 is substantially 0, and an oscillation center of the second oscillating voltage is substantially 0.
Claim 10
Dependent Claim
24 words
An apparatus according to claim 1, wherein said detecting means is provided with a frequency filter for filtering out frequencies outside a predetermined range.
Claim 11
Dependent Claim
28 words
An apparatus according to claim 1, wherein said image bearing member is provided with a photosensitive layer, and said apparatus comprising exposure means for said image bearing member.
Claim 12
Dependent Claim
74 words
An apparatus according to claim 10, wherein an image forming condition for said image bearing member is determined in accordance with a second electric current flowing through said charging member when said charging member changes the potential of a predetermined area of said image bearing member from V L which is provided by exposure means after detection by said detecting means, to a potential V3 which is different from the potential V L .
Claim 13
Dependent Claim
24 words
An apparatus according to claim 1, further comprising transfer means for electrostatically transferring an image from said image bearing member onto a transfer material.
Claim 14
Dependent Claim
33 words
An apparatus according to claim 12, wherein said transfer means does not charge said image bearing member when said charging member changes the potential of said image bearing member from V1 to V2.
Claim 15
Dependent Claim
24 words
An apparatus according to claim 11, further comprising transfer means for electrostatically transferring an image from said image bearing member onto a transfer material.
Claim 16
Dependent Claim
32 words
An apparatus according to claim 14, wherein said transfer means does not charge said image bearing member when the potential of said image bearing member is changed from V L to V3.
Claim 17
Dependent Claim
28 words
An apparats according to claim 1, wherein an image forming condition for said image bearing member is determined in accordance with the current detected by said detecting means.
Claim 18
Dependent Claim
158 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a first charging member, contactable to said image bearing member, for receiving a first oscillating voltage to charge said image bearing member; a second charging member, contactable to said image bearing member, for being supplied with a second oscillating voltage to charge said image bearing member, wherein an oscillation center of said second oscillating voltage is different from that of the first oscillating voltage; and detecting means for detecting an electric current flowing through said second charging member when said second charging member changes a potential of a predetermined area of said image bearing member from a potential V1, which is provided by said first charging member, to a potential V2 which is different from the potential V1, wherein, in the case said detected electric current increases, a decrease of a thickness of said image bearing layer can be determined.
Claim 19
Dependent Claim
158 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a first charging member, contactable to said image bearing member, for receiving a first oscillating voltage to charge said image bearing member; a second charging member, contactable to said image bearing member, for being supplied with a second oscillating voltage to charge said image bearing member, wherein an oscillation center of said second oscillating voltage is different from that of the first oscillating voltage; and detecting means for detecting an electric current flowing through said second charging member when said second charging member changes a potential of a predetermined area of said image bearing member from a potential V1, which is provided by said first charging member, to a potential V2 which is different from the potential V1, wherein, in the case said detected electric current increases, a decrease of a thickness of said image bearing layer can be determined.
Claim 20
Dependent Claim
21 words
An apparatus according to claim 17, further comprising display means for making a display when the current exceeds a predetermined range.
Claim 21
Dependent Claim
13 words
An apparatus according to claim 17, wherein the potential V1 is substantially 0.
Claim 22
Dependent Claim
18 words
An apparatus according to claim 19, wherein an oscillation center of said first oscillating voltage is substantially 0.
Claim 23
Dependent Claim
13 words
An apparatus according to claim 17, wherein the potential V2 is substantially 0.
Claim 24
Dependent Claim
18 words
An apparatus according to claim 21, wherein an oscillation center of the second oscillating voltage is substantially 0.
Claim 25
Dependent Claim
24 words
An apparatus according to claim 17, wherein said detecting means is provided with a frequency filter for filtering out frequencies outside a predetermined range.
Claim 26
Dependent Claim
23 words
An apparatus according to claim 17, wherein said first charging member transfers an image from said image bearing member to a transfer material.
Claim 27
Dependent Claim
28 words
An apparatus according to claim 17, wherein said image bearing member is provided with a photosensitive layer, and said apparatus comprising exposure means for said image bearing member.
Claim 28
Dependent Claim
76 words
An apparatus according to claim 25, wherein an image forming condition for said image bearing member is determined in accordance with a second electric current flowing through said first charging member when said first charging member changes the potential of a predetermined area of said image bearing member from V L which is provided by exposure means after detection by said detecting means, to a potential V3 which is different from the potential V L .
Claim 29
Dependent Claim
28 words
An apparatus according to claim 17, wherein an image forming condition for said image bearing member is determined in accordance with the current detected by said detecting means.
Claim 30
Dependent Claim
115 words
An image forming apparatus, comprising: an image bearing member having a photosensitive layer; a charging member, contactable to said image bearing member, for receiving an oscillating voltage to charge said image bearing member; exposure means for exposing said image bearing member to light; and detecting means for detecting an electric current flowing through said charging member when said charging member changes a potential of a predetermined area of said image bearing member from a potential V1 which is discharged by said exposure means, to a potential V2 which is different from the potential V1, wherein, in the case said detected electric current increases, a decrease of a thickness of the photosensitive layer can be determined.
Claim 31
Dependent Claim
115 words
An image forming apparatus, comprising: an image bearing member having a photosensitive layer; a charging member, contactable to said image bearing member, for receiving an oscillating voltage to charge said image bearing member; exposure means for exposing said image bearing member to light; and detecting means for detecting an electric current flowing through said charging member when said charging member changes a potential of a predetermined area of said image bearing member from a potential V1 which is discharged by said exposure means, to a potential V2 which is different from the potential V1, wherein, in the case said detected electric current increases, a decrease of a thickness of the photosensitive layer can be determined.
Claim 32
Dependent Claim
21 words
An apparatus according to claim 28, further comprising display means for making a display when the current exceeds a predetermined range.
Claim 33
Dependent Claim
25 words
An apparatus according to claim 28, wherein said image bearing member is rotatable, and the area corresponds to one full-rotation of said image bearing member.
Claim 34
Dependent Claim
13 words
An apparatus according to claim 28, wherein the potential V1 is substantially 0.
Claim 35
Dependent Claim
24 words
An apparatus according to claim 28, wherein said detecting means is provided with a frequency filter for filtering out frequencies outside a predetermined range.
Claim 36
Dependent Claim
24 words
An apparatus according to claim 28, further comprising transfer means for electrostatically transferring an image from said image bearing member onto a transfer material.
Claim 37
Dependent Claim
33 words
An apparatus according to claim 33, wherein said transfer means does not charge said image bearing member when said charging member changes the potential of said image bearing member from V1 to V2.
Claim 38
Dependent Claim
28 words
An apparatus according to claim 28, wherein an image forming condition for said image bearing member is determined in accordance with the current detected by said detecting means.
Claim 39
Dependent Claim
24 words
An apparatus according to claim 28, wherein the potential V2 is substantially 0, and an oscillation center of said oscillating voltage is substantially 0.
Claim 40
Dependent Claim
123 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a charging member, contactable to said image bearing member, for receiving an oscillating voltage to charge said image bearing member; potential applying means for providing substantially 0 potential with said image bearing member; and detecting means for detecting an electric current flowing through said charging member when said charging member changes a potential of a predetermined area of said image bearing member from 0 V which is provided by said potential applying means to a potential V2 which is different from 0 V, wherein, in the case said detected electric current increases, a decrease of a thickness of said image bearing layer can be determined.
Claim 41
Dependent Claim
123 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a charging member, contactable to said image bearing member, for receiving an oscillating voltage to charge said image bearing member; potential applying means for providing substantially 0 potential with said image bearing member; and detecting means for detecting an electric current flowing through said charging member when said charging member changes a potential of a predetermined area of said image bearing member from 0 V which is provided by said potential applying means to a potential V2 which is different from 0 V, wherein, in the case said detected electric current increases, a decrease of a thickness of said image bearing layer can be determined.
Claim 42
Dependent Claim
107 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a charging member, contactable to said image bearing member, for charging said image bearing member; and detecting means for detecting an electric current flowing through said charging member at a time when an area of said image bearing member, which has been charged to a potential V1 by said charging member supplied with a first voltage, is charged to a potential V2 by said charging member supplied with a second voltage different from said first voltage; wherein said electric current changes with a thickness of said image bearing member.
Claim 43
Dependent Claim
107 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a charging member, contactable to said image bearing member, for charging said image bearing member; and detecting means for detecting an electric current flowing through said charging member at a time when an area of said image bearing member, which has been charged to a potential V1 by said charging member supplied with a first voltage, is charged to a potential V2 by said charging member supplied with a second voltage different from said first voltage; wherein said electric current changes with a thickness of said image bearing member.
Claim 44
Dependent Claim
21 words
An apparatus according to claim 38, further comprising display means for making a display when the current exceeds a predetermined range.
Claim 45
Dependent Claim
31 words
An apparatus according to claim 38, wherein said image bearing member is rotatable, and wherein said area of said image bearing member corresponds to one full-rotation of said image bearing member.
Claim 46
Dependent Claim
40 words
An apparatus according to claim 38, wherein when the potential V1 is provided, said charging member is provided with a first oscillating voltage, and when the potential V2 is provided, said charging member is supplied with a second oscillating voltage.
Claim 47
Dependent Claim
13 words
An apparatus according to claim 38, wherein the potential V1 is substantially 0.
Claim 48
Dependent Claim
25 words
An apparatus according to claim 41, wherein the potential V1 is substantially 0, and an oscillation center of the first oscillating voltage is substantially 0.
Claim 49
Dependent Claim
13 words
An apparatus according to claim 38, wherein the potential V2 is substantially 0.
Claim 50
Dependent Claim
25 words
An apparatus according to claim 41, wherein the potential V2 is substantially 0, and an oscillation center of the second oscillating voltage is substantially 0.
Claim 51
Dependent Claim
28 words
An apparatus according to claim 38, wherein said image bearing member is provided with a photosensitive layer, and said apparatus comprising exposure means for said image bearing member.
Claim 52
Dependent Claim
74 words
An apparatus according to claim 46, wherein an image forming condition for said image bearing member is determined in accordance with a second electric current flowing through said charging member when said charging member changes the potential of a predetermined area of said image bearing member from V L which is provided by exposure means after detection by said detecting means, to a potential V3 which is different from the potential V L .
Claim 53
Dependent Claim
24 words
An apparatus according to claim 38, further comprising transfer means for electrostatically transferring an image from said image bearing member onto a transfer material.
Claim 54
Dependent Claim
33 words
An apparatus according to claim 48, wherein said transfer means does not charge said image bearing member when said charging member changes the potential of said image bearing member from V1 to V2.
Claim 55
Dependent Claim
28 words
An apparatus according to claim 38, wherein an image forming condition for said image bearing member is determined in accordance with the current detected by said detecting means.
Claim 56
Dependent Claim
94 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a charging member, contactable to said image bearing member, for charging said image bearing member; detecting means for detecting an electric current flowing through said charging member, which has been charged to a potential V1 by said charging member supplied with a first voltage, is charged to a potential V2 by said charging member supplied with a second voltage different from said first voltage; and comparing means for comparing the electric current with a predetermined current.
Claim 57
Dependent Claim
94 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a charging member, contactable to said image bearing member, for charging said image bearing member; detecting means for detecting an electric current flowing through said charging member, which has been charged to a potential V1 by said charging member supplied with a first voltage, is charged to a potential V2 by said charging member supplied with a second voltage different from said first voltage; and comparing means for comparing the electric current with a predetermined current.
Claim 58
Dependent Claim
21 words
An apparatus according to claim 51, further comprising display means for making a display when the current exceeds a predetermined range.
Claim 59
Dependent Claim
31 words
An apparatus according to claim 51, wherein said image bearing member is rotatable, and wherein said area of said image bearing member corresponds to one full-rotation of said image bearing member.
Claim 60
Dependent Claim
40 words
An apparatus according to claim 51, wherein when the potential V1 is provided, said charging member is provided with a first oscillating voltage, and when the potential V2 is provided, said charging member is supplied with a second oscillating voltage.
Claim 61
Dependent Claim
13 words
An apparatus according to claim 51, wherein the potential V1 is substantially 0.
Claim 62
Dependent Claim
25 words
An apparatus according to claim 54, wherein the potential V1 is substantially 0, and an oscillation center of the first oscillating voltage is substantially 0.
Claim 63
Dependent Claim
13 words
An apparatus according to claim 51, wherein the potential V2 is substantially 0.
Claim 64
Dependent Claim
25 words
An apparatus according to claim 54, wherein the potential V2 is substantially 0, and an oscillation center of the second oscillating voltage is substantially 0.
Claim 65
Dependent Claim
28 words
An apparatus according to claim 51, wherein said image bearing member is provided with a photosensitive layer, and said apparatus comprising exposure means for said image bearing member.
Claim 66
Dependent Claim
74 words
An apparatus according to claim 59, wherein an image forming condition for said image bearing member is determined in accordance with a second electric current flowing through said charging member when said charging member changes the potential of a predetermined area of said image bearing member from V L which is provided by exposure means after detection by said detecting means, to a potential V3 which is different from the potential V L .
Claim 67
Dependent Claim
24 words
An apparatus according to claim 51, further comprising transfer means for electrostatically transferring an image from said image bearing member onto a transfer material.
Claim 68
Dependent Claim
33 words
An apparatus according to claim 61, wherein said transfer means does not charge said image bearing member when said charging member changes the potential of said image bearing member from V1 to V2.
Claim 69
Dependent Claim
28 words
An apparatus according to claim 51, wherein an image forming condition for said image bearing member is determined in accordance with the current detected by said detecting means.
Claim 70
Dependent Claim
111 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a charging member, contactable to said image bearing member, for charging said image bearing member; and detecting means for detecting an electric current flowing through said charging member at a time when an area of said image bearing member, which has been charged to a potential V1 by said charging member supplied with a first voltage, is charged to a potential V2 by said charging member supplied with a second voltage different from said first voltage; wherein a life of said image bearing member is discriminated on the basis of said electric current.
Claim 71
Dependent Claim
111 words
An image forming apparatus, comprising: an image bearing member having an image bearing layer for bearing an image; a charging member, contactable to said image bearing member, for charging said image bearing member; and detecting means for detecting an electric current flowing through said charging member at a time when an area of said image bearing member, which has been charged to a potential V1 by said charging member supplied with a first voltage, is charged to a potential V2 by said charging member supplied with a second voltage different from said first voltage; wherein a life of said image bearing member is discriminated on the basis of said electric current.
Claim 72
Dependent Claim
21 words
An apparatus according to claim 64, further comprising display means for making a display when the current exceeds a predetermined range.
Claim 73
Dependent Claim
31 words
An apparatus according to claim 64, wherein said image bearing member is rotatable, and wherein said area of said image bearing member corresponds to one full-rotation of said image bearing member.
Claim 74
Dependent Claim
40 words
An apparatus according to claim 64, wherein when the potential V1 is provided, said charging member is provided with a first oscillating voltage, and when the potential V2 is provided, said charging member is supplied with a second oscillating voltage.
Claim 75
Dependent Claim
13 words
An apparatus according to claim 64, wherein the potential V1 is substantially 0.
Claim 76
Dependent Claim
25 words
An apparatus according to claim 67, wherein the potential V1 is substantially 0, and an oscillation center of the first oscillating voltage is substantially 0.
Claim 77
Dependent Claim
13 words
An apparatus according to claim 64, wherein the potential V2 is substantially 0.
Claim 78
Dependent Claim
25 words
An apparatus according to claim 67, wherein the potential V2 is substantially 0, and an oscillation center of the second oscillating voltage is substantially 0.
Claim 79
Dependent Claim
28 words
An apparatus according to claim 64, wherein said image bearing member is provided with a photosensitive layer, and said apparatus comprising exposure means for said image bearing member.
Claim 80
Dependent Claim
74 words
An apparatus according to claim 72, wherein an image forming condition for said image bearing member is determined in accordance with a second electric current flowing through said charging member when said charging member changes the potential of a predetermined area of said image bearing member from V L which is provided by exposure means after detection by said detecting means, to a potential V3 which is different from the potential V L .
Claim 81
Dependent Claim
24 words
An apparatus according to claim 64, further comprising transfer means for electrostatically transferring an image from said image bearing member onto a transfer material.
Claim 82
Dependent Claim
33 words
An apparatus according to claim 74, wherein said transfer means does not charge said image bearing member when said charging member changes the potential of said image bearing member from V1 to V2.
Claim 83
Dependent Claim
28 words
An apparatus according to claim 64, wherein an image forming condition for said image bearing member is determined in accordance with the current detected by said detecting means.
References Cited (Backward Citations)
US3935517A
Cited
JPS5890652A
Cited
JPS58136057A
Cited
JPS5969774A
Cited
JPS63149669A
Cited
US4851960A
Cited
US4727453A
Cited
JPS63167380A
Cited
US5164779A
Cited
US5089851A
Cited
EP0338546A2
Cited
US5144368A
Cited
US5140371A
Cited
US5160967A
Cited
US5184180A
Cited
JPH0457068A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-15 | 1999-07-17 | 2000-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-15 | 2003-07-17 | 2004-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-15 | 2007-07-17 | 2008-01-16 | $7700.00 | Window Closed / Lapsed |