US5157441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dark decay control system utilizing two electrostatic voltmeters
Assignee: Xerox Corp
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Filing: 1991-09-05
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Granted: 1992-10-20
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Expires: 2011-09-05
Abstract
Abstract A single pass tri-level imaging apparatus and method. Compensation for the effects of dark decay on the background voltage, V Mod , and the color toner patch, V tc readings is provided using two ESVs (ESV 1 and ESV 2 ), the former located prior to the color or DAD housing and the latter after it. Since the CAD and black toner patch voltages are measured (using ESV 2 ) after dark decay and CAD voltage loss have occurred, no compensation for these readings is required. The DAD image voltage suffers little dark decay change over the life of the P/R so the average dark decay can be built into the voltage target.
Inventors
- 👤 Mark A. Scheuer
- 👤 Patricia J. Donaldson
- 👤 Daniel W. MacDonald
- 👤 Anthony J. Paolini
- 👤 Kenneth S. Palumbo
- 👤 Robin E. Berman
- 👤 Carl B. Hurwitch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:39
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/5033; G03G15/5037; G03G15/01; G03G15/0105; G03G15/011; G03G15/5041
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
196 words
In a method of creating tri-level images on a charge retentive surface, the steps including: moving said charge retentive surface past a plurality of process stations including a development station comprising a plurality of developer structures; uniformly charging said charge retentive surface; using an exposure device, forming a tri-level image on said charge retentive surface, said tri-level image comprising two images at different voltage levels and a background voltage level; forming a test patch on said charge retentive surface; sensing the voltage level of said background voltage level prior to the charge retentive surface being moved through a development station and generating a first electrical signal representative of a first voltage level; sensing the voltage level of said background voltage after it passes the first of a plurality of developer structures in said development station and generating a second electrical signal representative of a second voltage level; sensing the voltage level of said test patch prior to said test patch passing through said first of a plurality of developer structures and generating a third electrical signal; using two of said signals for determining the output level of said exposure device for forming said background voltage level.
Claim 2
Dependent Claim
196 words
In a method of creating tri-level images on a charge retentive surface, the steps including: moving said charge retentive surface past a plurality of process stations including a development station comprising a plurality of developer structures; uniformly charging said charge retentive surface; using an exposure device, forming a tri-level image on said charge retentive surface, said tri-level image comprising two images at different voltage levels and a background voltage level; forming a test patch on said charge retentive surface; sensing the voltage level of said background voltage level prior to the charge retentive surface being moved through a development station and generating a first electrical signal representative of a first voltage level; sensing the voltage level of said background voltage after it passes the first of a plurality of developer structures in said development station and generating a second electrical signal representative of a second voltage level; sensing the voltage level of said test patch prior to said test patch passing through said first of a plurality of developer structures and generating a third electrical signal; using two of said signals for determining the output level of said exposure device for forming said background voltage level.
Claim 3
Dependent Claim
29 words
The method according to claim 1 including the step of using all of said signals for determining the output level of said exposure device for forming said test patch.
Claim 4
Dependent Claim
30 words
The method according to claim 2 wherein the output of said exposure device for forming said background voltage level is determined according to the formula: V.sub.Mod @Color=0.38×V.sub.Mod @ESV.sub.1 +0.62×V.sub.Mod @ESV.sub.2.
Claim 5
Dependent Claim
31 words
The method according to claim 2 wherein the output of said exposure device for forming said test patch is determined according to the formula: V.sub.tc @Color=V.sub.tc @ESV.sub.1 -0.465(V.sub.Mod @ESV.sub.1 -V.sub.Mod @Color).
Claim 6
Dependent Claim
31 words
The method according to claim 3 wherein the output of said exposure device for forming said test patch is determined according to the formula: V.sub.tc @Color=V.sub.tc @ESV.sub.1 -0.465(V.sub.Mod @ESV.sub.1 -V.sub.Mod @Color).
Claim 7
Dependent Claim
18 words
The method according to claim 1 wherein said two of said signals comprise said first and second signals.
Claim 8
Dependent Claim
30 words
The method according to claim 6 wherein the output of said exposure device for forming said background voltage level is determined according to the formula: V.sub.Mod @Color=0.38×V.sub.Mod @ESV.sub.1 +0.62×V.sub.Mod @ESV.sub.2.
Claim 9
Dependent Claim
30 words
The method according to claim 1 wherein the output of the means for forming said test patch is determined according to the formula: V.sub.tc @Color=V.sub.tc @ESV.sub.1 -0.465(V.sub.Mod @ESV.sub.1 -V.sub.Mod @Color).
Claim 10
Dependent Claim
183 words
In a method of creating tri-level images on a charge retentive surface-, the steps including: moving said charge retentive surface past a plurality of process stations including a development station comprising a plurality of developer structures; uniformly charging said charge retentive surface; using an exposure device, forming a tri-level image on said charge retentive surface, said tri-level image comprising two images at different voltage levels and a background voltage level; forming a test patch on said charge retentive surface; sensing the voltage level of said background voltage level prior to the charge retentive surface being moved through a development station and generating a first electrical signal; sensing the voltage level of said background voltage after it passes the first of a plurality of developer structures in said development station and generating a second electrical signal; sensing the voltage level of said test patch prior to said test patch passing through said first of a plurality of developer structures and generation a third electrical signal; using all of said signals for determining the output level of said exposure device for forming said test patch.
Claim 11
Dependent Claim
183 words
In a method of creating tri-level images on a charge retentive surface-, the steps including: moving said charge retentive surface past a plurality of process stations including a development station comprising a plurality of developer structures; uniformly charging said charge retentive surface; using an exposure device, forming a tri-level image on said charge retentive surface, said tri-level image comprising two images at different voltage levels and a background voltage level; forming a test patch on said charge retentive surface; sensing the voltage level of said background voltage level prior to the charge retentive surface being moved through a development station and generating a first electrical signal; sensing the voltage level of said background voltage after it passes the first of a plurality of developer structures in said development station and generating a second electrical signal; sensing the voltage level of said test patch prior to said test patch passing through said first of a plurality of developer structures and generation a third electrical signal; using all of said signals for determining the output level of said exposure device for forming said test patch.
Claim 12
Dependent Claim
208 words
Apparatus for creating tri-level images on a charge retentive surface, said apparatus comprising: means for moving said charge retentive surface past a plurality of process stations including a development station comprising a plurality of developer structures; means for uniformly charging said charge retentive surface; an exposure device for forming a tri-level image on said charge retentive surface, said tri-level image comprising two images at different voltage levels and a background voltage level; means for forming a test patch on said charge retentive surface; means for sensing the voltage level of said background voltage level prior to the charge retentive surface being moved through a development station and generating a first electrical signal representative of a first voltage level; means for sensing the voltage level of said background voltage after it passes the first of a plurality of developer structures in said development station and generating a second electrical signal representative of a second voltage level; means for sensing the voltage level of said test patch prior to said test patch passing through said first of a plurality of developer structures and generation a third electrical signal; means for using two of said signals for determining the output level of said exposure device for forming said background voltage level.
Claim 13
Dependent Claim
208 words
Apparatus for creating tri-level images on a charge retentive surface, said apparatus comprising: means for moving said charge retentive surface past a plurality of process stations including a development station comprising a plurality of developer structures; means for uniformly charging said charge retentive surface; an exposure device for forming a tri-level image on said charge retentive surface, said tri-level image comprising two images at different voltage levels and a background voltage level; means for forming a test patch on said charge retentive surface; means for sensing the voltage level of said background voltage level prior to the charge retentive surface being moved through a development station and generating a first electrical signal representative of a first voltage level; means for sensing the voltage level of said background voltage after it passes the first of a plurality of developer structures in said development station and generating a second electrical signal representative of a second voltage level; means for sensing the voltage level of said test patch prior to said test patch passing through said first of a plurality of developer structures and generation a third electrical signal; means for using two of said signals for determining the output level of said exposure device for forming said background voltage level.
Claim 14
Dependent Claim
26 words
Apparatus according to claim 10 including for using all of said signals for determining the output level of said exposure device for forming said test patch.
Claim 15
Dependent Claim
29 words
Apparatus according to claim 11 wherein the output of said means for forming said test patch is determined according to the formula: V.sub.tc @Color=V.sub.tc @ESV.sub.1 -0.465(V.sub.Mod @ESV.sub.1 -V.sub.Mod @Color).
Claim 16
Dependent Claim
17 words
Apparatus according to claim 10 wherein said two of said signals comprise said first and second signals.
Claim 17
Dependent Claim
29 words
Apparatus according to claim 10 wherein the output of said exposure device for forming said background voltage level is determined according to the formula: V.sub.Mod @Color=0.38×V.sub.Mod @ESV.sub.1 +0.62×V.sub.Mod @ESV.sub.2.
Claim 18
Dependent Claim
29 words
Apparatus according to claim 10 wherein the output of said means for forming said test patch is determined according to the formula: V.sub.tc @Color=V.sub.tc @ESV.sub.1 -0.465(V.sub.Mod @ESV.sub.1 -V.sub.Mod @Color).
Claim 19
Dependent Claim
195 words
Apparatus for creating tri-level images on a charge retentive surface, said apparatus comprising: means for moving said charge retentive surface past a plurality of process stations including a development station comprising a plurality of developer structures; means for uniformly charging said charge retentive surface; an exposure device for forming a tri-level image on said charge retentive surface, said tri-level image comprising two images at different voltage levels and a background voltage level; means for forming a test patch on said charge retentive surface; means for sensing the voltage level of said background voltage level prior to the charge retentive surface being moved through a development station and generating a first electrical signal; means for sensing the voltage level of said background voltage after it passes the first of a plurality of developer structures in said development station and generating a second electrical signal; means for sensing the voltage level of said test patch prior to said test patch passing through said first of a plurality of developer structures and generation a third electrical signal; means for using all of said signals for determining the output level of said exposure device for forming said test patch.
Claim 20
Dependent Claim
195 words
Apparatus for creating tri-level images on a charge retentive surface, said apparatus comprising: means for moving said charge retentive surface past a plurality of process stations including a development station comprising a plurality of developer structures; means for uniformly charging said charge retentive surface; an exposure device for forming a tri-level image on said charge retentive surface, said tri-level image comprising two images at different voltage levels and a background voltage level; means for forming a test patch on said charge retentive surface; means for sensing the voltage level of said background voltage level prior to the charge retentive surface being moved through a development station and generating a first electrical signal; means for sensing the voltage level of said background voltage after it passes the first of a plurality of developer structures in said development station and generating a second electrical signal; means for sensing the voltage level of said test patch prior to said test patch passing through said first of a plurality of developer structures and generation a third electrical signal; means for using all of said signals for determining the output level of said exposure device for forming said test patch.
Claim 21
Dependent Claim
24 words
Apparatus according to claim 16 wherein the output of said exposure device for forming said background voltage level is determined according to the formula.
Claim 22
Dependent Claim
29 words
Apparatus according to claim 17 wherein the output of said means for forming said test patch is determined according to the formula: V.sub.tc @Color=V.sub.tc @ESV.sub.1 -0.465(V.sub.Mod @ESV.sub.1 -V.sub.Mod @Color).
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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) | 1995-10-20 | 1996-04-20 | 1996-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-20 | 2000-04-20 | 2000-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-20 | 2004-04-20 | 2004-10-20 | $7700.00 | Window Closed / Lapsed |