US4937664A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming apparatus
Assignee: Canon Inc
•
Filing: 1988-11-22
•
Granted: 1990-06-26
•
Expires: 2008-11-22
Abstract
Abstract An image forming apparatus has a plurality of image forming stations capable of forming different images which are to be correctly registered and superimposed. Elimination of possible image misregistration in each image station is executed on the basis of the result of detection of register marks which are formed by each image forming station. The correction is executed at a timing which is independent from image forming sequences performed by each imgae forming station in accordance with image signals, e.g., during warming-up of the apparatus after the initial application of the power immediately after the input of image forming operation start instruction through a start key, or after completion of production of a predetermined number of copies counted from the last misregistration correcting operation.
Inventors
- 👤 Kazuyoshi Chiku
- 👤 Tomohiro Aoki
- 👤 Yasushi Murayama
- 👤 Yoshihiko Hirose
- 👤 Takashi Uchida
- 👤 Kunihiko Matsuzawa
- 👤 Kazunori Kanekura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:23
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/50; H04N1/506; G; G03; G03G; G03G15/00; G03G15/01; G03G15/0142; G03G15/0178; G03G15/0194; H04N1/04; H04N1/047; G03G2215/00; G03G2215/01; G03G2215/0103; G03G2215/0119; H04N1/113; H04N1/1135; H04N1/12; H04N2201/00; H04N2201/024; H04N2201/02406; H04N2201/02416; H04N2201/04; H04N2201/047; H04N2201/04701; H04N2201/0471; H04N2201/04712; H04N2201/04715; H04N2201/04722; H04N2201/04729; H04N2201/04731; H04N2201/04732; H04N2201/04753; H04N2201/04755; H04N2201/04758; H04N2201/04767; H04N2201/04781; H04N2201/04789; H04N2201/04791
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
94 words
An image forming apparatus comprising: image forming means for forming an image on a transfer material in accordance with image signals, and for forming a register mark indicative of an image forming position; detection means for detecting said register mark and for determining image misregistration in accordance with said register mark; correction means for correcting, in accordance with said detection means, a misregistration of the image forming position; and control means for controlling said correction means such that said correction means operates independently of an image forming operation performed by said image forming means.
Claim 2
Dependent Claim
94 words
An image forming apparatus comprising: image forming means for forming an image on a transfer material in accordance with image signals, and for forming a register mark indicative of an image forming position; detection means for detecting said register mark and for determining image misregistration in accordance with said register mark; correction means for correcting, in accordance with said detection means, a misregistration of the image forming position; and control means for controlling said correction means such that said correction means operates independently of an image forming operation performed by said image forming means.
Claim 3
Dependent Claim
24 words
An image forming apparatus according to claim 1, wherein said image forming means forms an image on said transfer material by an electrophotographic process.
Claim 4
Dependent Claim
46 words
An image forming apparatus according to claim 1, wherein said correction means includes first correction means for correcting image misregistration in a main scanning direction of said image forming means, said first correction means operating in accordance with the result of detection by said detection means.
Claim 5
Dependent Claim
45 words
An image forming apparatus according to claim 1, wherein said correction means includes second correction means for correcting image misregistration in a sub-scanning direction of said image forming means, said second correction means operating in accordance with the result of detection by said detection means.
Claim 6
Dependent Claim
43 words
An image forming apparatus according to claim 1, wherein said control means controls said correction means to effect the correction of image misregistration in a period commencing when power is supplied to said apparatus and terminating when warm-up of said apparatus is completed.
Claim 7
Dependent Claim
39 words
An image forming apparatus according to claim 1, wherein said control means controls said correction means to effect the correction of image misregistration in response to a signal for starting the image forming operation of said image forming means.
Claim 8
Dependent Claim
61 words
An image forming apparatus according to claim 1, further comprising conveyor means for conveying said transfer material, and wherein said image forming means includes means for forming different images on a plurality of image carriers, and image transfer means for transferring said different images on said image carriers to the same transfer material which is being conveyed by said conveyor means.
Claim 9
Dependent Claim
23 words
An image forming apparatus according to claim 2, wherein said register marks are formed on said conveyor means by said image forming means.
Claim 10
Dependent Claim
33 words
An image forming apparatus according to claim 7, wherein said conveyor means includes a belt for conveying said transfer material and said marks are formed on said belt by said image forming means.
Claim 11
Dependent Claim
49 words
An image forming apparatus according to claim 1, further comprising counting means for counting the number of images produced by said image forming means, and said control means controls said correction means to effect the correction of image misregistration when said counter means has counted to a predetermined number.
Claim 12
Dependent Claim
40 words
An image forming apparatus according to claim 10, wherein when said counting means has counted to said predetermined number, said control means postpones correction of image misregistration until an image forming operation of said image forming means has been completed.
Claim 13
Dependent Claim
154 words
An image forming apparatus comprising: a plurality of image forming stations each for forming an image on a transfer material, and each having an image carrier and image forming means arranged around said image carrier, each of said image forming means forming a register mark on its associated image carrier; conveyor means for conveying the transfer material, each of said image forming stations transferring an associated register mark onto said conveyor means; detection means for detecting the register marks corresponding to the associated image carriers; misregistration calculating means for calculating misregistration information corresponding to misregistration of an image forming position of said image forming stations based on the detection of the register marks by said detection means; and correction means for correcting image misregistration in accordance with the misregistration information from said misregistration calculating means such that said correction means operates independently of an image forming sequence in all of said image forming stations.
Claim 14
Dependent Claim
154 words
An image forming apparatus comprising: a plurality of image forming stations each for forming an image on a transfer material, and each having an image carrier and image forming means arranged around said image carrier, each of said image forming means forming a register mark on its associated image carrier; conveyor means for conveying the transfer material, each of said image forming stations transferring an associated register mark onto said conveyor means; detection means for detecting the register marks corresponding to the associated image carriers; misregistration calculating means for calculating misregistration information corresponding to misregistration of an image forming position of said image forming stations based on the detection of the register marks by said detection means; and correction means for correcting image misregistration in accordance with the misregistration information from said misregistration calculating means such that said correction means operates independently of an image forming sequence in all of said image forming stations.
Claim 15
Dependent Claim
32 words
An image forming apparatus according to claim 12, wherein in a accordance with the image misregistration information, said correction means corrects misregistration in a main scanning direction of each image forming station.
Claim 16
Dependent Claim
30 words
An image forming apparatus according to claim 12, wherein in accordance with the image misregistration information said correction means corrects misregistration in a sub-scanning direction of each image forming station.
Claim 17
Dependent Claim
51 words
An image forming apparatus according to claim 12, wherein said correction means completes the correction of image misregistration in accordance with the image misregistration information for all the image forming stations in a period commencing when power is supplied to said apparatus and terminating when warm-up of said apparatus is completed.
Claim 18
Dependent Claim
38 words
An image forming apparatus according to claim 12, wherein said correction means completes the correction of image misregistration in accordance with the image misregistration information for all the image forming stations before the image forming sequence is commenced.
Claim 19
Dependent Claim
24 words
An image forming apparatus according to claim 12, wherein said image forming means forms images by an electrophotographic process in accordance with image signals.
Claim 20
Dependent Claim
47 words
An image forming apparatus according to claim 12, wherein said correction means completes the correction of image misregistration in accordance with the image misregistration information for all the image forming stations each time a predetermined number of consecutive images has been formed by said image forming apparatus.
Claim 21
Dependent Claim
29 words
An image forming apparatus according to claim 18, wherein said correction means postpones correction of image misregistration until image forming operations of said image forming stations have been completed.
Claim 22
Dependent Claim
66 words
An image forming apparatus comprising: image forming means for forming an image in accordance with image signals; correction means for correcting misregistration of an image formed by said image forming means; counter means for counting the number of images formed by said image forming means; and control means for controlling the operation of said correction means in accordance with the value counted by said counter means.
Claim 23
Dependent Claim
66 words
An image forming apparatus comprising: image forming means for forming an image in accordance with image signals; correction means for correcting misregistration of an image formed by said image forming means; counter means for counting the number of images formed by said image forming means; and control means for controlling the operation of said correction means in accordance with the value counted by said counter means.
Claim 24
Dependent Claim
45 words
An image forming apparatus according to claim 20, wherein said image forming means includes a plurality of image forming stations for forming different images, and said correction means is designed for effecting correction of misregistration between the different images formed by different image forming stations.
Claim 25
Dependent Claim
53 words
An image forming apparatus according to claim 20, wherein said control means is designed for controlling said correction means such that said correction means executes the correction of image misregistration after completion of an image forming sequence when said counting means has counted said predetermined number during execution of said image forming sequence.
Claim 26
Dependent Claim
51 words
An image forming apparatus according to claim 20, wherein said image forming means includes image writing means for writing different images on a plurality of image carriers, conveyor means for conveying a transfer material, and image transfer means for transferring said different images from said image carriers to said transfer material.
Claim 27
Dependent Claim
57 words
An image forming apparatus according to claim 23, wherein said correction means includes register mark forming means for enabling said image forming means to form register marks on said transfer material, and detection means for detecting said register marks, whereby the correction of image misregistration is conducted in accordance with the detection performed by said detection means.
Claim 28
Dependent Claim
64 words
An image forming apparatus having a warm-up period commencing after application of power, said image forming apparatus comprising: image forming means for forming an image in accordance with image signals; correction means for correcting misregistration of an image formed by said image forming means; and control means for controlling said correction means such that correction of image misregistration is executed in the warm-up period.
Claim 29
Dependent Claim
64 words
An image forming apparatus having a warm-up period commencing after application of power, said image forming apparatus comprising: image forming means for forming an image in accordance with image signals; correction means for correcting misregistration of an image formed by said image forming means; and control means for controlling said correction means such that correction of image misregistration is executed in the warm-up period.
Claim 30
Dependent Claim
51 words
An image forming apparatus according to claim 25, wherein said image forming means includes image writing means for writing different images on a plurality of image carriers, conveyor means for conveying a transfer material, and image transfer means for transferring said different images from said image carriers to said transfer material.
Claim 31
Dependent Claim
45 words
An image forming apparatus according to claim 25, wherein said image forming means includes a plurality of image forming stations for forming different images, and said correction means is designed for effecting correction of misregistration between the different images formed by different image forming stations.
Claim 32
Dependent Claim
57 words
An image forming apparatus according to claim 25, wherein said correction means includes register mark forming means for enabling said image forming means to form register marks on said transfer material, and detection means for detecting said register marks, whereby the correction of image misregistration is conducted in accordance with the detection performed by said detection means.
Claim 33
Dependent Claim
48 words
An image forming apparatus according to claim 28, wherein said control means controls the operation of said correction means such that the correction of image misregistration is commenced during the warm-up period and produces a warm-up completion signal after the correcting operation of said correction means is completed.
Claim 34
Dependent Claim
65 words
An image forming apparatus comprising: image forming means for forming an image in accordance with image signals; input means for instructing commencement of an image forming operation; correction means for correcting misregistration of an image formed by said image forming means; and control means for controlling said correction means such that correction means conducts the correction of image misregistration in response to said input means.
Claim 35
Dependent Claim
65 words
An image forming apparatus comprising: image forming means for forming an image in accordance with image signals; input means for instructing commencement of an image forming operation; correction means for correcting misregistration of an image formed by said image forming means; and control means for controlling said correction means such that correction means conducts the correction of image misregistration in response to said input means.
Claim 36
Dependent Claim
45 words
An image forming apparatus according to claim 30, wherein said image forming means includes a plurality of image forming stations for forming different images, and said correction means is designed for effecting correction of misregistration between the different images formed by different image forming stations.
Claim 37
Dependent Claim
51 words
An image forming apparatus according to claim 30, wherein said image forming means includes image writing means for writing different images on a plurality of image carriers, conveyor means for conveying a transfer material, and image transfer means for transferring said different images from said image carriers to said transfer material.
Claim 38
Dependent Claim
57 words
An image forming apparatus according to claim 32, wherein said correction means includes register mark forming means for enabling said image forming means to form register marks on said transfer material, and detection means for detecting said register marks, whereby the correction of image misregistration is conducted in accordance with the detection performed by said detection means.
Claim 39
Dependent Claim
114 words
An image forming apparatus comprising: image forming means for forming an image on a transfer material in accordance with image signals, and for forming a register mark indicative of an image forming position; conveyor means for conveying said transfer material, wherein said register mark is formed on said conveyor means by said image; detection means for detecting said register mark and for determining image misregistration in accordance with said register mark; correction means for correcting, in accordance with said detection means, a misregistration of the image forming position; and control means for controlling said correction means such that said correction means operates independently of an image forming operation performed by said image forming means.
Claim 40
Dependent Claim
114 words
An image forming apparatus comprising: image forming means for forming an image on a transfer material in accordance with image signals, and for forming a register mark indicative of an image forming position; conveyor means for conveying said transfer material, wherein said register mark is formed on said conveyor means by said image; detection means for detecting said register mark and for determining image misregistration in accordance with said register mark; correction means for correcting, in accordance with said detection means, a misregistration of the image forming position; and control means for controlling said correction means such that said correction means operates independently of an image forming operation performed by said image forming means.
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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) | 1993-06-25 | 1993-12-25 | 1994-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-25 | 1997-12-25 | 1998-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-25 | 2001-12-25 | 2002-06-26 | $7700.00 | Window Closed / Lapsed |