US4872037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming apparatus and control system therefor
Assignee: Ricoh Co Ltd
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Filing: 1988-03-02
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Granted: 1989-10-03
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Expires: 2008-03-02
Abstract
Abstract A control system for a color copier which sets up an adequate color copying time for any particular size of paper sheets. A color document is repeatedly scanned to sequentially expose a single photoconductive drum, which is rotated at a constant speed, to a plurality of separated color components. Each of the latent images is developed by toner complementary in color to the color component associated with the latent image, and sequentially transferred to a paper sheet. The control system includes a paper size setting circuit, a scanning sensor for sensing the start of a scanning, and a home sensor for sensing an instantaneous angular position of the transfer drum. A control circuit is constructed to determine a transfer start and a transfer end time in response to a paper size signal, an output signal of the scanning sensor, and an output signal of the home sensor, and to variably control the rotation speed of the transfer drum during the interval between the transfer start and transfer end times so as to register the leading end of a paper sheet loaded on the transfer drum and that of each of the toner images.
Inventors
- 👤 Nobuo Kasahara
- 👤 Tosio Nakahara
- 👤 Masayosi Watanuki
- 👤 Tadahide Sawamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:36
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/01; G03G15/0105; G03G15/0131; G03G15/14; G03G15/16; G03G15/163; G03G15/1635; G03G15/165; G03G15/1655; G03G2215/00; G03G2215/01; G03G2215/019; G03G2215/0196
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
165 words
A control system for a color copier having optics for scanning, photoconductive means, and transfer means, comprising: paper size setting means for setting a size of a paper sheet to be used before a copying operation; scanning sensor means for sensing a start of a scanning performed by said optics; home sensor means for sensing an instantaneous angular position of said transfer means; and control means for determining a transfer start time and a transfer end time in response to a paper size signal outputted by said paper size setting means, an output signal of said scanning sensor means, and an output of said home sensor means, and variably controlling a rotation speed of said transfer means during an interval between said transfer start and transfer end times so as to register a leading edge of a paper sheet loaded on said transfer means and a leading edge of each of toner images formed on said photoconductive means and different in color from each other.
Claim 2
Dependent Claim
165 words
A control system for a color copier having optics for scanning, photoconductive means, and transfer means, comprising: paper size setting means for setting a size of a paper sheet to be used before a copying operation; scanning sensor means for sensing a start of a scanning performed by said optics; home sensor means for sensing an instantaneous angular position of said transfer means; and control means for determining a transfer start time and a transfer end time in response to a paper size signal outputted by said paper size setting means, an output signal of said scanning sensor means, and an output of said home sensor means, and variably controlling a rotation speed of said transfer means during an interval between said transfer start and transfer end times so as to register a leading edge of a paper sheet loaded on said transfer means and a leading edge of each of toner images formed on said photoconductive means and different in color from each other.
Claim 3
Dependent Claim
27 words
A control system as claimed in claim 1, further comprising drive means for driving said optics, said photoconductive means and said transfer means independently of each other.
Claim 4
Dependent Claim
18 words
A control system as claimed in claim 2, wherein each of said drive means comprises a servo motor.
Claim 5
Dependent Claim
23 words
A control system as claimed in claim 3, further comprising servo circuits for controlling the drive of said motors independently of each other.
Claim 6
Dependent Claim
17 words
A control system as claimed in claim 4, further comprising pulse generating means for generating reference pulses.
Claim 7
Dependent Claim
25 words
A control system as claimed in claim 1, wherein said photoconductive means and said transfer means comprise a photoconductive drum and a transfer drum, respectively.
Claim 8
Dependent Claim
25 words
A control system as claimed in claim 1, wherein said photoconductive means and said transfer means comprise a photoconductive belt and a transfer belt, respectively.
Claim 9
Dependent Claim
185 words
A control system for a color copier having optics for scanning, photoconductive means, and transfer means, comprising: paper size setting means for setting a size of a paper sheet to be used before a start of a copying operation to produce a paper size set signal; scanning sensor means for sensing a start of a scanning performed by said optics to produce a scanning start signal; home sensor means for sensing a home position of said transfer means to produce a home position signal; drive means for driving said optics, said photoconductive means and said transfer means independently of each other; control means for realizing different timing programs which are selectable, the respective timing program for timing the complete copying operation sequence being changeable in dependence upon said paper size set signal of said paper size setting means, said scanning start signal of said scanning sensor means, and said home position signal of said home sensor means; and servo means for adjusting predetermined operation parameters of said color copier so as to selectively adjust said respective drive means in response to said respective timing program.
Claim 10
Dependent Claim
185 words
A control system for a color copier having optics for scanning, photoconductive means, and transfer means, comprising: paper size setting means for setting a size of a paper sheet to be used before a start of a copying operation to produce a paper size set signal; scanning sensor means for sensing a start of a scanning performed by said optics to produce a scanning start signal; home sensor means for sensing a home position of said transfer means to produce a home position signal; drive means for driving said optics, said photoconductive means and said transfer means independently of each other; control means for realizing different timing programs which are selectable, the respective timing program for timing the complete copying operation sequence being changeable in dependence upon said paper size set signal of said paper size setting means, said scanning start signal of said scanning sensor means, and said home position signal of said home sensor means; and servo means for adjusting predetermined operation parameters of said color copier so as to selectively adjust said respective drive means in response to said respective timing program.
Claim 11
Dependent Claim
25 words
A control system as claimed in claim 8, wherein said photoconductive means and said transfer means comprise a photoconductive drum and a transfer drum, respectively.
Claim 12
Dependent Claim
25 words
A control system as claimed in claim 8, wherein said photoconductive means and said transfer means comprise a photoconductive belt and a transfer belt, respectively.
Claim 13
Dependent Claim
19 words
A control system as claimed in claim 8, wherein each of said drive means comprises an own servo motor.
Claim 14
Dependent Claim
21 words
A control system as claimed in claim 11, wherein said servo means comprises servo circuit for independently controlling said servo motors.
Claim 15
Dependent Claim
17 words
A control system as claimed in claim 12, further comprising pulse generating means for generating reference pulses.
Claim 16
Dependent Claim
65 words
An image forming apparatus comprising, in combination: movable photoconductive means and transfer means one of which is greater in circumferential length than the other by a multiple other than integral multiples; and drive control means for independently controlling said photoconductive means and said transfer means including a home sensor means for generating a home position signal upon sensing a home position of said transfer means.
Claim 17
Dependent Claim
65 words
An image forming apparatus comprising, in combination: movable photoconductive means and transfer means one of which is greater in circumferential length than the other by a multiple other than integral multiples; and drive control means for independently controlling said photoconductive means and said transfer means including a home sensor means for generating a home position signal upon sensing a home position of said transfer means.
Claim 18
Dependent Claim
30 words
An image forming apparatus as claimed in claim 14, further comprising scanning optics which is driven by said drive control means independently of said photoconductive means and said transfer means.
Claim 19
Dependent Claim
86 words
An image forming apparatus as claimed in claim 15, wherein said drive control means comprises: scanning sensor means for producing a scanning start signal upon sensing a start of a scanning performed by said optics; photoconductive means driving means for driving said photoconductive means at a predetermined speed; transfer means driving means for driving said transfer means; and control means responsive to said scanning start signal and said home position signal for controlling said transfer means driving means to vary the speed of said transfer means.
Claim 20
Dependent Claim
126 words
An image forming apparatus as claimed in claim 16, wherein said drive control means further comprises paper size setting means for setting a paper size of a paper sheet to be used before a copying operation to produce a paper size signal, said drive control means being constructed to detect a transfer start and a transfer end time in response to said paper size signal, said scanning start signal, and said home position signal and, during an interval between said transfer start and transfer end times, variably control the speed of said transfer means to bring a leading edge of a paper sheet loaded on said transfer means and a leading edge of a toner image formed on said photoconductive means into register with each other.
Claim 21
Dependent Claim
26 words
An image forming apparatus as claimed in claim 16, wherein said photoconductive means driving means and said transfer means driving means each comprises a servo motor.
Claim 22
Dependent Claim
19 words
An image forming apparatus as claimed in claim 18, further comprising servo means for controllably driving said servo motors.
Claim 23
Dependent Claim
18 words
An image forming apparatus as claimed in claim 19, further comprising pulse generating means for generating reference pulses.
Claim 24
Dependent Claim
26 words
An image forming apparatus as claimed in claim 14, wherein said photoconductive means and said transfer means comprise a photoconductive drum and a transfer drum, respectively.
Claim 25
Dependent Claim
26 words
An image forming apparatus as claimed in claim 14, wherein said photoconductive means and said transfer means comprise a photoconductive belt and a transfer belt, respectively.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-02 | 1993-04-03 | 1993-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-02 | 1997-04-03 | 1997-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-02 | 2001-04-03 | 2001-10-03 | $7700.00 | Window Closed / Lapsed |