Information
-
Patent Grant
-
6389241
-
Patent Number
6,389,241
-
Date Filed
Tuesday, January 16, 200123 years ago
-
Date Issued
Tuesday, May 14, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
-
CPC
-
US Classifications
Field of Search
US
- 399 15
- 399 44
- 399 45
- 399 42
- 399 66
- 399 67
- 399 68
- 399 69
- 399 389
- 399 46
- 399 71
-
International Classifications
- G03G1500
- G03G1516
- G03G1520
-
Abstract
An electrophotography hard copy apparatus uses automated sensing devices to provide current condition signals and operational feedback signals to optimize subsystem operational parameters. Monitoring of ambient environmental conditions, subsystem operational parameters, and a print medium from input through output and the final printed text or image for predetermined characteristics is used to generate signals indicative of conditions that can be altered by commands to the apparatus' subsystems to optimize print quality.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the fields of electrophotography and hard copy apparatus and, more specifically, to the control of printing and fixing alphanumeric text and images on print media using automatic sensing devices, feedback, and digital control techniques in a laser hard copy apparatus.
2. Description of Related Art
Basically, in electrophotography—the basic technology behind laser printing such as with Hewlett-Packard Company's HP™ LaserJet™ products—a latent image on a charged surface area of a photoconductor is developed, by application of an electroscopic toner to the area. The developed image is transferred to a hard copy medium. Both wet toner chemicals and dry toner powders are known to be used to develop an image using heat fusible toner particles. The image is then fixed, that is, fused to the print medium. (For ease of explanation, the word paper will be used as an exemplary print medium hereinafter; however, as will be recognized by a person skilled in the art, the invention described herein is applicable to all forms of hard copy media such as papers, card stock, transparencies, envelopes, and the like; the word image, or sometimes print depending on the context, is used as a generic term for all alphanumeric text, graphics, photographs, and the like; no limitation on the scope of the invention is intended nor should any be implied.)
In its basic aspects, a laser printing engine
124
, shown schematically in
FIG. 6
(Prior Art), applies a charge with a scorotron charger
136
to a moving photoconductive insulating surface area of a photoconductor, or photoreceptor,
126
. The surface area is exposed to a pattern of light
138
,
140
. A latent image of the pattern is formed on the charged surface which is then developed by application of electroscopic toner
128
,
130
,
132
,
134
(in this example, color toner) to the photoconductive material. The developed image is transferred to a hard copy medium
152
using a transfer drum
148
with a transfer corona charge unit
150
and transferred to the medium
152
by using another transfer corona unit
154
. The image bearing medium
152
is then passed to the fuser
160
subsystem where the toner is fused, or fixed. The photoconductive material insulating surface is then erased
146
, cleaned
142
,
144
, and reused for the next image. This basic construct is used in a variety of state of the art products such as computer printers and plotters, copiers and hard copy scanners, facsimile machines, multifunctional peripherals, and the like (referred to generically hereinafter as printers).
In addition to visual perception of print quality, the effectiveness or reliability of the electrophotographic process is determined in part by how well the toner image stays fixed on the media after the media exits the printing operations. Having an effective temperature in the fuser subsystem is vital to ensuring optimized image quality and achievable print. Too low of a fusing temperature can result in toner which is not properly fixed to the print media; a low strength bond between the toner and the media can cause toner to break from the media with a low degree of mechanical stress. Too high of a fusing temperature can result in melted toner adhering to the surface of the fixing device and offsetting the toner from the correct location on the print media. Either case results in undesirable print defects, often referred to as “artifacts.” Variables that determine the effectiveness of the fusing process include (1) paper parameters (the major parameters including surface roughness, thickness, moisture content, chemical composition, base weight, and size), (2) environmental parameters (the major parameters including temperature and humidity of the ambient air), and (3) fuser assembly operational parameters (the major parameters including temperature, pressure, nip size, surface properties of roller, paper speed, and fuser electrical bias).
Another factor in the determination of final print quality will be the bias voltages used in various components of the printer subsystems, e.g., the transfer voltage on the image transfer roller, the charges on various electrostatic charge/discharge elements, and the like as would be known to a person skilled in the art.
In many commercially available systems, many of these parameters are neither sensed nor controlled. The solution to their individual and possibly cumulative negative effect on print quality is to over-design the system to cover worst case scenarios. For example, a fixed fuser temperature is often used, set for a “typical media” for which the printer is compatible. However, fixed fuser temperatures cannot accommodate media types that require more heat to properly fuse the toner to the special media; fixed fuser temperatures may be too high for special media; media types requiring lower fuser temperatures may be damaged, e.g., wrinkled, by the relatively high heat of a fixed temperature fuser.
Other conventional arrangements provide user controls for manually adjusting operational parameters. Typically, such manual adjustments are made after print problems are already occurring; thus, print monitoring is required for prompt attention.
In co-pending applications, the common assignee has provided some specific, advanced solutions:
U.S. Pat. No. 6,011,939, based on Ser. No. 09/126,628, filed by co-inventor Martin on Jul. 30,1998, addresses SENSING PRINT MEDIA SIZE TO TEMPERATURE CONTROL A MULTI-HEATING ELEMENT FIXING DEVICE by relating media size to given print data;
U.S. Pat. Appl. Ser. No. 09/348,650, filed by co-inventor Martin et al., on Jul. 6,1999, addresses IMAGE FORMING DEVICES, FUSING ASSEMBLIES AND METHODS OF FORMING AN IMAGE by monitoring media qualitative characteristics to adjust fusing parameters;
U.S. Pat. Appl. Ser. No. 09/354,638, filed by co-inventor Martin et al., on Jul. 16,1999 addresses AUTOMATIC FUSER TEMPERATURE CONTROL; sensed media vibrations are related to print media type and fuser temperature selected using the measured sympathetic response;
U.S. Pat. Appl. Ser. No. 09/384,716, filed by co-inventor Martin et al., on Aug. 26,1999, addresses issues with respect to METHOD AND APPARATUS FOR DETECTING IMAGE MEDIUM SURFACE DEFECTS IN AN IMAGING SYSTEM by monitoring the fuser subsystem pressure roller and heated roller surface conditions; and
U.S. Pat. Appl. Ser. No. 09/430,356, filed by co-inventor Martin, on Oct. 28, 1999, addresses issues with respect to FIXING DEVICE CONTROL BASED UPON MEDIA TEXTURE MEASUREMENT using optical sensing; rough media requires a higher fuser temperature than smooth media.
One type of planar type fuser is shown in assignee's patent for a THERMAL TRANSFER APPARATUS FOR FUSING PRINT DYE ON A MEDIA, U.S. Pat. No. 5,541,636, file Jun. 2, 1994 by G.B. Ingram.
There is a need for an overall system approach to detecting the necessary properties of the paper and ambient environment as the paper is being processed and using feedback information to control the printing operational parameters, automatically optimizing in real-time the processes for each media type supported by the device.
SUMMARY OF THE INVENTION
The present invention relates to a method and apparatus for controlling the fuser assembly operation by substantially continuously feeding sensor information, viz., signals indicative of fuser operating parameters, ambient environment conditions, and current copy paper characteristics and performance, to a control circuit. As media is fed into the hard copy apparatus from an input supply and throughout the printing process, a variety of detection devices determine media properties, ambient environmental conditions, and current fuser assembly operating conditions such that feedback signals are sent to the controller and real time adjustments made to fuser assembly operating conditions appropriate to optimize the fixing of an image on the next sheet as it passes through. Moreover, output print characteristic detectors can be used to provide direct print quality feedback to the controller.
In its basic aspects, the present invention provides a print fusing system, including: print fuser having a plurality of individually controllable heaters; a controller connected to said heaters; and connected to said controller, at least one sensor for ambient environmental conditions, at least one sensor for media parameters, at least one sensor for current print fuser system conditions, such that signals from each said sensor to said controller are provided to said controller for adjusting fusing system conditions to optimal for the next media sheet passing therethrough.
In another aspect, the present invention provides a hard copy apparatus, having mechanisms for applying toner to a print media sheet in a predetermined pattern and a controller for printing and media transport subsystems of the apparatus, including: connected to the controller, a toner fuser device having a plurality of individually controllable heaters for thermally fixing the toner to the sheet, at least one sensor for ambient environmental conditions, at least one sensor for media parameters, at least one sensor for current fusing system conditions, wherein signals from each said sensor are provided to said controller for adjusting fusing system conditions to optimal for the print media sheet passing therethrough.
In another aspect, the present invention provides a method for hard copy print fusing using automated sensing devices in a hard copy apparatus, including the steps of: monitoring for a set of predetermined characteristics a sheet of print media transported from an input of the hard copy apparatus to the output of the hard copy apparatus; producing a set of signals indicative of the predetermined characteristics; post-print deposition operations, running a printed sheet through a print fusing subsystem; and controlling print fusing operational parameters of said print fusing subsystem by analyzing said signals and automatically adjusting said operational parameters to an optimal set of parameters for the sheet.
In another aspect, the present invention provides a method for controlling hard copy apparatus subsystems printing operation parameters, via a hard copy apparatus controller, including the steps of: recognizing print medium characteristics during said medium input; recognizing said subsystems printing operation parameters current states; and based on said steps of recognizing print medium characteristics and recognizing said current states, commanding said subsystems to adjust printing operation parameters from said current states to adjusted states for optimizing print quality in accordance with said characteristics.
In another aspect, the present invention provides a hard copy apparatus, having mechanisms for electrophotographically processing image printing data as a printed page and mechanisms for controlling the mechanisms for electrophotographically processing image printing data, including printing and media transport subsystems thereof, including: connected to the mechanisms for controlling, at least one sensor for ambient environmental conditions, at least one sensor for media parameters and at least one sensor for print quality characteristics, wherein signals from each said sensor to said mechanisms for controlling are provided to said mechanisms for controlling for determining and adjusting operational parameters of said mechanisms for electrophotographically process image printing data to optimal levels for printing the image data on a media sheet passing through said apparatus.
In another aspect, the present invention provides a memory device having a program for controlling electrophotography device subsystems including: computer code enabling the recognition of signals indicative of print media characteristics, signals indicative of printed image characteristics, and signals indicative of current electrophotography device subsystems operational parameters; computer code determining optimal electrophotography device subsystems operational parameters based upon analysis of said signals indicative of print media characteristics and signals indicative of printed image characteristics; and computer code commanding adjustments to the electrophotography device subsystems operational parameters based upon the analysis of said signals indicative of print media characteristics and signals indicative of printed image characteristics.
Some of the advantages of the present invention are:
it improves control of laser printer operations in real time;
it improves fusing hard copy toner;
it improves print quality;
it provides automatic adjustments to printing processes across multiple print media types;
it provides a system where no end-user interaction is required at the hard copy apparatus due to media and environment changes;
it alleviates the necessity for print job monitoring; and
it provides data useful in determining whether maintenance processes should be implemented.
The foregoing summary and list of advantages is not intended by the inventors to be an inclusive list of all the aspects, objects, advantages and features of the present invention nor should any limitation on the scope of the invention be implied therefrom. This Summary is provided in accordance with the mandate of 37 C.F.R. 1.73 and M.P.E.P. 608.01 (d) merely to apprise the public, and more especially those interested in the particular art to which the invention relates, of the nature of the invention in order to be of assistance in aiding ready understanding of the patent in future searches. Other objects, features and advantages of the present invention will become apparent upon consideration of the following explanation and the accompanying drawings, in which like reference designations represent like features throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is an isometric view of an exemplary image laser printer embodiment in accordance with the present invention.
FIG. 2
is a cross-sectional view schematic illustration of the image forming device as shown in
FIG. 1
taken in plane
2
—
2
.
FIG. 3
is an illustrative representation of an imager and fuser subsystems of the image forming device as shown in FIG.
1
.
FIG. 4
is a schematic block diagram for sensing and control subsystems for an image forming device as shown in
FIG. 1
in accordance with the present invention.
FIG. 5
is a flow chart of the basic process in accordance with the present invention using the equipment as shown in
FIGS. 1-4
.
FIG. 6
(Prior Art) is an exemplary laser-type electrophotographic hard copy apparatus.
FIG. 7
is an alternative embodiment of the present invention including the embodiment shown in FIG.
4
.
FIG. 8
is a flow chart of the basic process in accordance with the present invention as shown in FIG.
7
.
The drawings referred to in this specification should be understood as not being drawn to scale except if specifically annotated.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is made now in detail to a specific embodiment of the present invention, which illustrates the best mode presently contemplated by the inventors for practicing the invention. Alternative embodiments are also briefly described as applicable. Subtitles are used hereinafter for ease of reference; no limitation on the scope of the invention is intended nor should any be implied.
LASER-TYPE APPARATUS PRINTING
FIG. 1
shows an exemplary image forming device
10
embodying the present invention. The depicted image forming device
10
comprises an electrophotographic printer. The image forming device
10
includes a housing
12
arranged to house internal components (not seen in this view, but see
FIGS. 2 and 3
described hereinafter). A user interface, or input control panel,
14
is provided upon an upper surface
11
of the housing
12
. The manual input control panel
14
includes a key pad
13
and a display
15
. An end-user can control operations using the key pad
9
or with driver software from a computer (not shown, but see
FIGS. 4 and 7
described hereinafter) connected with the image forming device
10
, monitoring operations using the display
15
. An outfeed tray
16
is provided for receiving printed, hard copy pages.
In accordance with the present invention,
FIG. 2
is a schematic illustration in transparent view of the various internal components of the image forming device
10
. The image forming device
10
includes a laser scanner
17
, media supply tray
20
, a representative sensor
22
, an imager
24
, a developing
26
subassembly, a fuser
28
subassembly, and a controller
30
. A media path, represented by multi-headed arrow
32
, is provided through the device
10
. Rollers are provided along the media path
32
to guide media in a “downstream” direction from the media supply tray
20
towards the outfeed tray
16
. More specifically, a pick roller
34
, feed rollers
36
, transport rollers
38
, registration rollers
40
, a roller driven conveyor
42
, delivery rollers
44
, and output rollers
46
are arranged in succession to transport and guide media along the media path
32
.
The image forming device
10
includes an input device
50
configured to receive an image in a printer configuration, namely a port coupled to the controller
30
; an exemplary input device
50
includes a parallel connection coupled with an associated computer or network (neither shown). Such a computer or network generally provides digital files (e.g., page description language (PDL) files) corresponding to an image to be produced within the image forming device
10
.
Developing subassembly
26
is positioned adjacent the media path
32
and provides developing material, such as toner, for forming the images. The developing assembly
26
is preferably implemented as a disposable cartridge.
An exemplary sensor
22
is positioned to determine a qualitative characteristic of the apparatus or media. Further description of a plurality of such sensors is given hereinafter with respect to
FIGS. 4-8
.
The imager
24
subassembly, including developing assembly
26
, is positioned adjacent the media path
32
and transfers toner material appropriately onto the media passing, corresponding to the data received via the input
50
. The fuser
28
subassembly is adjacent the media path
32
and is located downstream from the imager
24
subassembly. The fuser
28
fuses the developing material with the media.
Exemplary electrostatic brushes
70
,
72
are provided at various locations of the apparatus. One electrically bias-controlled brush
70
is provided to discharge the imaging roller
52
. Another electrostatic brush in contact with the media sheet in media path
32
is used to bias the media sheet upstream of the fuser
28
. It is also known to use such brushes (not shown) to discharge the fuser roller
66
and the media sheet
18
downstream of the fuser
28
.
Referring now also to
FIG. 3
, further details of image forming operation are described. The imager
24
subassembly includes an imaging roller (alternatively a belt)
52
and a transfer roller
54
. The imaging roller
52
is a photoconductor or photosensitive drum which is insulative in the absence of incident light and conductive when illuminated. The imaging roller
52
rotates in a clockwise direction represented by arrows in FIG.
3
. The rotating imaging roller
52
is charged uniformly by a charging device such as charging roller
56
. The charging roller
56
provides a negative charge upon the surface of the imaging roller
52
. A laser device
58
scans across the charged surface of the imaging roller
52
and writes an image to be formed by selectively discharging areas of the surface where developing material
61
, e.g., toner, is to adhere. A developer
60
applies the developing material
61
on the surface when and wherever the negatively-charged developing material
61
is attracted to the discharged areas and repelled by the charged areas of the imaging roller
52
surface. A media sheet
18
being transported along the media path
32
passes through the nip
62
of the imaging roller and a transfer roller
54
where the developed image on the surface is transferred to the sheet. A bias voltage, also referred to as the “transfer voltage,” from a high voltage power supply
701
is applied to the transfer roller which contacts the backside of the media sheet
18
inducing an electric field through the sheet. The magnitude of the induced field in the nip
62
between the imaging roller
52
and the transfer roller
54
is determined by the transfer voltage, the resistivity of the media sheet
18
, and the dielectric thickness of the media sheet. The induced electric field causes the developing material
61
to move from the imaging roller
52
to the media sheet, forming the desired hard copy image.
Residual developing material upon the imaging roller
52
may be removed at a cleaning station
64
to prepare the imaging roller for the application of a subsequent image.
The fuser
28
subassembly is positioned downstream of the imager
24
. A fusing roller
66
preferably includes internal heating devices
67
to impart a heat flux to the developing material
61
on the media sheet
18
being transported along media path
32
. The media sheet
18
passes through a fuser nip
69
between the fusing roller and a pressure roller
68
. Application of the heat flux fuses the developing material
61
cohesively to the media sheet
18
. The temperature in the fuser nip
69
and heat flux is dependent upon the properties of the developing material
61
, the velocity of the media sheet
18
, the surface finish of the sheet, and the thermal conductivity and heat capacity of the sheet.
Control of the various printing operation parameters of the apparatus
10
and its subassemblies are provided in accordance with the present invention.
INPUT SENSING AND ANALYSIS
FIG. 4
is a schematic block diagram illustrating one embodiment of the sensing, analysis, and control subsystem in accordance with the present invention. Signal flow is represented by arrows connecting the various elements of the subsystem. Generally, the hard copy apparatus as shown in
FIGS. 1
,
2
and
3
includes the internal controller
30
(such as a general purpose microprocessor or application specific integrated circuit (“ASIC”) based control printed circuit board), connected to a host computer
407
, from which the printer operations are directed, including, for example, fuser operational parameters, i.e., the fusing subsystem temperature, pressure, transport speed operating conditions. Digital signal processing and computer code control techniques are used via the controller
30
in accordance with the state of the art.
As shown in this exemplary embodiment, specifically
FIGS. 2 and 3
, the fuser
28
subsystem is a roller type having a fusing roller
66
and a pressure roller
68
in peripheral contact and through the nip
69
which a developed page to be fixed is transported. In addition to the heating profiles (circumferential and cylindrical length) across the fusing roller
66
surface, other fuser assembly operational parameters, such as media speed through the nip
69
, pressure in the fuser nip
69
between the rollers
66
,
68
, and an imposed latent electrical charge on one roller (generally the heated fusing roller
67
) need to be controlled. Thus, the optimal fusing process for a specific sheet will be a function of selecting the correct heating profile, pressure, speed, and fuser charge for a next sheet to be fixed.
Returning to
FIG. 4
, one or more ambient “Environmental” condition sensors
403
can be distributed in the printer engine (
FIG. 3
) so that ambient temperature and humidity can be monitored continuously. Ambient temperature and ambient humidity detectors are well known. Digital temperature sensors such as commercially available thermocouples or thermistors can be employed; humidity sensors, such as model HMM22D or 30C manufactured by Vaisala Inc. of Sunnyvale, Calif., can be employed.
One or more “Media Type” sensors
405
can be provided on-board the printer
10
(FIG.
1
). Most printer control panels
14
(
FIG. 1
) have end-user media type selection input capability. Most often, media type is provided from the Host Computer
407
printing application program as header code in a downloaded print job. However, the printer also can be provided with individual, automatic sensors
405
for media type detection. For example, a known manner optical detector can be located near the paper path input to determine if the next sheet of media is clear, viz. an overhead transparency, the signal from which can be used to have the controller
30
change to a transparency default set of operational parameter control settings. Thus, while a print download program instruction may be specifying plain paper, the on-board type sensors
405
may detect a transparency sheet and over-ride the download program instructions.
Looking again to
FIG. 4
, one or more “Media Size” sensors
409
can be provided on-board the printer
10
(FIG.
1
). Most printer control panels
14
(also only in
FIG. 1
) have end-user media size selection input capability. Most often, media size is provided from the host computer
407
printing application program as header code in a downloaded print job. However, the printer also can be provided with individual, automatic sensors
405
for media size detection. U.S. Pat. No. 5,574,551 by Kazakoff for a PRINT MEDIA SUPPLY APPARATUS WITH MEDIA PARAMETER DETECT CAPABILITY ( assigned to the common assignee herein and incorporated herein by reference) teach an automatic detection of size of print media in a supply bin.
Moreover media size can be inferred from the print job data; U.S. Pat. No. 6,011,939, based on Ser. No. 09/126,628, filed by co-inventor Martin on Jul. 30, 1998, addresses SENSING PRINT MEDIA SIZE TO TEMPERATURE CONTROL A MULTI-HEATING ELEMENT FIXING DEVICE is incorporated herein by reference.
As shown in
FIG. 4
, other print media characteristic detection sensors
411
can be provided (represented jointly by a single element in
FIG. 4
labeled “Media Characteristic(s) Sensor(s)”). U.S. patent application Ser. No. 09/348,650, filed by co-inventor Martin et al., on Jul. 6,1999, addresses IMAGE FORMING DEVICES, FUSING ASSEMBLIES AND METHODS OF FORMING AN IMAGE by monitoring various media qualitative characteristics to adjust fusing parameters.
A specific Next Sheet Characteristic of concern to the fusing process is media thickness. Turning briefly to
FIG. 2
, any simple, known manner, measurement of deflection of input feed rollers
36
or transport rollers
38
during a pick and feed cycle can provide a signal indicative of media thickness. As another known manner technique, but more costly, complex optical sensors or micrometers can be employed. In U.S. patent application Ser. No. 09/348,650, filed by Martin et al., on Jul. 6,1999, addresses IMAGE FORMING DEVICES, FUSING ASSEMBLIES AND METHODS OF FORMING AN IMAGE, the co-applicants herein disclose a number of specific techniques for determining surface characteristics of a sheet of media (assigned to the common assignee herein and incorporated herein by reference). Those devices can also be used in tandem to measure media thickness.
Another “Next Sheet Characteristic” which affects the toner fixing process is media texture, as rough media requires a higher fuser temperature than smooth media. U.S. patent application Ser. No. 09/430,356, filed by co-inventor Martin, on Oct. 28, 1999, addresses issues with respect to FIXING DEVICE CONTROL BASED UPON MEDIA TEXTURE MEASUREMENT using optical sensing (assigned to the common assignee herein and incorporated herein by reference). A commercially available, reflective sensor manufactured by Honeywell Corp. of Morristown, N.J., having part number HOA0708 can be employed to measure media texture.
Still another “Next Sheet Characteristic” which affects the toner fixing process is paper surface charge. Induced paper surface charge can be inferred from the known bias voltage and associated imposed charge employed by the image transfer subsystem (see e.g.,
FIG. 3
, subsystem element
24
herein). The magnitude of the induced field is determined by the bias voltage and the resistivity and the dielectric thickness of the media sheet (element
18
, FIG.
3
). Surface charge can be detected using an appropriately adapted electrostatic voltmeter such as the commercially available model 368 by Trek Inc. of Medina, N.Y.
Yet another “Next Sheet Characteristic” which affects the toner fixing process is media temperature. Media temperature can be detected using an appropriately adapted, known manner, thermistor device such as the commercially available model 44201 by Omega company of Stamford, Conn.
A further “Next Sheet Characteristic” which affects the toner fixing process is heat capacity and thermal conductivity. These characteristics can be detected using an appropriately adapted, known manner, thermocouple device (such as the commercially available model TT-K-36 by Omega company of Stamford, Conn.) placed upstream and downstream of the fuser (or other known heat sources sought to be controlled).
A further “Next Sheet Characteristic” which affects the toner fixing process is media resistivity (surface and volume). Media resistivity can be detected using an appropriately adapted, known manner electrometer such as the commercially available model MCP-HT450 by Mitsubishi Chemical company of Tokyo, Japan, or an appropriately adapted, electrostatic measurement system such as the commercially available model DRA-2000L, commercially available from Quality Engineering Associates, Burlington, Mass.
Still another “Next Sheet Characteristic” which affects the toner fixing process is media moisture content. Moisture content can be detected using an appropriately adapted moisture content meter such as the commercially available model MOISTREX™ MX5000E by Infrared Engineering Limited company of Essex, England.
Thus, in combination, the various media sensors
405
,
409
,
411
, collectively referred to as the input sensors, provide the controller
30
with important information with respect to the media
18
(FIG.
3
), while the Environmental Sensor(s)
403
provide ambient environmental current condition data.
Where practical, it would be advantageous if the sensors employed in the present invention be adjustable in sensitivity (shown symbolically as a variable resistor/potentiometer) so that post-manufacturing testing and adjustments can be made to calibrate the system and optimize performance.
It should be recognized at this point that not all of these detection devices may be necessary for a particular implementation. Depending upon the printer used and the variety of media types supported thereby, the monitored characteristics and conditions can be limited. Moreover, each sensor output variable can be weighted during signal analysis by the controller
30
; in other words, for each implementation, the appropriate sensor devices need to be prioritized and weighted and a cost effective design developed.
FUSER SENSING, ANALYSIS, OPERATION
Returning to
FIG. 4
, the fuser
28
′ subassembly operational conditions feedback is critical to optimizing the current, as well as next, fusing cycle. It is known in the art to divide a fuser roller
66
or the like into a plurality of heat zones,
1
through N, related to different media sizes which can be employed by the printer
10
(FIGS.
1
&
2
). Thus, a thermistor
413
is positioned to provide a feedback signal to the controller
30
indicative of current temperature in each zone (represented by boxes labeled “Thermistor
1
”. . . “Thermistor N”) or relative to a predetermined set of zones.
As discussed in the Background section above, a fuser
28
/
28
′ operational parameter critical to the fixing process is the pressure in the nip
69
. Pressure in the nip is controlled by any known manner electromechanical adjustment device such as a solenoid with the pressure measured by a known manner gauge such as an adapted load cell model LCL-040G, by Omega company (the entire mechanism represented in
FIG. 4
as a box labeled “Nip Pressure”
415
).
Again, as discussed hereinabove, another fuser
28
/
28
′ operational parameter critical to the fixing process is the latent charge at the fuser roller
66
. Any known manner potential source, such as brush
72
,
FIG. 2
, can be employed to create the “Electrical Bias”
416
.
Media speed through the nip will determine fixing dwell time. Media transport mechanisms through the printer
10
(
FIGS. 1 & 2
) are well known in the art and therefore represented simply as the “Media Transport”
417
.
Thus, as with the environmental
403
and input sensors
405
,
409
,
411
, the fuser
28
′ condition sensors and control devices
413
,
415
,
416
,
417
also provide feedback to the controller
30
so that real time adjustments can be made to the fuser heater elements
419
(“Heater Element
1
” . . . “Heater Element N”), Media Transport
417
mechanisms, Nip Pressure
415
and Electrical Bias
416
control mechanisms.
OUTPUT SENSING AND ANALYSIS
The final print output to the outfeed tray
16
(
FIGS. 1 & 2
) can be analyzed by one or more “Print Sensor(s)”
421
(
FIG. 4
) as the sheet
32
passes from the fuser
28
to the delivery rollers
44
and output rollers
46
(
FIG. 2
only). Print quality detection can be used to analyze several characteristics and provide feedback to the controller
30
.
One important characteristic of print quality is media moisture content. As with the Media Characteristic(s) detection devices
411
on the input side of the fuser
28
/
28
′, moisture content can be detected using an appropriately adapted moisture content meter such as the commercially available model MOISTREX™ MX5000E by Infrared Engineering Limited company of Essex, England. If the moisture content is above a predetermined threshold for the media type, a signal indicative of the condition can be sent to the controller
30
such that the temperature in the appropriate heater elements
419
is increased.
Another important characteristic of print quality is the condition of the sheet
18
(
FIG. 3
) as a whole. If the output print is excessively curled, scallop-edged, wavy (also known as “potato chipping”), cockled, or otherwise deformed, a likely cause is too high a temperature in the fuser
28
/
28
′. Known manner optical or mechanical planarity displacement detection devices can be employed. Moreover, the mechanisms taught in U.S. patent application Ser. No. 09/348,650, filed by Martin et al., on Jul. 6, 1999, addresses IMAGE FORMING DEVICES, FUSING ASSEMBLIES AND METHODS OF FORMING AN IMAGE (assigned to the common assignee herein and incorporated herein by reference) and provides a number of specific techniques for determining surface characteristics of a sheet of media.
Yet another important characteristic of print quality is toner adhesion strength. This is a more difficult characteristic to determine because known, reasonably costed, detection methods require destruction of the print. Known manner scratch tests and devices in which the force is measured to shear print from the surface would require a test sheet for the media of choice would have to be run through a complete printing cycle. Such devices are expensive piece parts. However, these factors do not preclude the use of such devices, providing feedback signals for adjusting fuser temperature zones and fuser nip pressure in combination in a printer or plotter where output is critical and each copy is relatively expensive, e.g., D-size, full color, engineering plots, art and photographic or art prints and posters, and the like. Adaptable optical sensing of print characteristics on media are disclosed, for example, in U.S. Pat. No. 5,825,378 (Beauchamp), U.S. Pat. Nos. 5,600,350 and 5,404,020 by Cobbs et al., U.S. Pat. No. 5,451,990 (Sorenson et al.) (each assigned to the common assignee herein and incorporated herein by reference).
CONTROLLED FUSER OPERATIONS
In addition to
FIGS. 1-4
, refer now also to FIG.
5
. From the very start of printer operation, step
501
, optimization can begin. Predetermined default settings for the fuser subsystem
28
/
28
′ can be set and then immediately adjusted if signals from the Environmental Sensor(s)
403
indicate via the controller
30
analysis if better initial fuser optimization settings should be set.
Media (
18
,
FIG. 2
) is then picked (
34
) and fed (
36
,
38
,
40
,
42
), step
503
, through the imaging and transfer subsystems (
17
,
26
,
24
) while, based on the signals from the Environmental Sensor(s)
403
, host computer input
407
, the indicative feedback signals, step
505
, of Media Type sensor(s)
405
, Media Size Sensor(s)
409
, and Media Characteristics Sensors
411
are sent to the controller
30
. Real time analysis of theses signals, step
507
, determines the best current fusing parameters which are converted by the controller, step
509
, into commands for fuser assembly operational parameter adjustments, namely, temperature, heating profile, nip pressure, and latent charge. The box labeled step
509
also represents fuser conditions reported generally continuously by sensors
413
,
415
,
416
from the time power ON is initiated as with step
501
.
For one simple example, based on the input sensor
403
,
405
,
409
,
411
signals, a beginning temperature in appropriate zones of the fuser roller
66
can be set by the controller
30
. If a print job calls for many copies, the fuser temperature can be set for continuous heating of the appropriate zones rather than turning on and off for each sheet wherein heating profile fluctuations could effect print quality over the job run.
Note that it also is specifically intended that the end-user have control capability to input requirements that override one or more sensor inputs, step
511
.
The media
32
travels through the fuser
28
subsystem, step
513
.
As the media
32
passes from the fuser
28
subsystem via the output transport mechanism
44
,
46
to the outfeed tray
16
, output print quality characteristics are detected by the Print Sensor(s)
421
, step
515
, and fed back to the controller
30
(note
FIG. 5
feedback arrow to step
507
). In other words, during or once a first sheet has been fixed, feedback from the fuser
28
/
28
′ (nip pressure, media speed, electrical charge on the fuser roller) and Print Sensor(s)
421
provide further feedback for further fuser operational parameter updating. Thus, optimum fusing commands results from real time analysis of media and environment characteristics and fuser operations, step
517
, for each sheet printed before, during, and after fixing the toner to the sheet.
A specific example of sensor analysis and fuser parameter setting now can be explored in the nature of logical truth tables and known manner lookup table (“LUT”) digital memory. Let the Heater Elements
419
be numbered En where n is the element number for each predetermined zone and odd numbers represent full width zones.
For the Media Size Sensor(s)
409
, let paper size be factor P1=n, where e.g., n=1 for narrowest size, n=2 widest size, as would be appropriate for a particular implementation.
For the Media Characteristic(s) Sensor(s)
411
, let paper resistivity be factor R1=n, where e.g., n=1 for a low resistance, n=2 for a moderate resistance, n=3 for a high resistance; let paper texture be factor R2=n, where e.g., n=1 for rough, n=2 for normal, n=3 for smooth; let paper thickness be factor T1=n, where e.g., n=1 for thick, n=2 for normal, n=3 for thin.
For the Environmental Sensor(s)
403
, actual air temperature and humidity can be in standard units and related to temperature and moisture content input and feedback signals, so let factor T2=“Xn” for temperature and factor H1=“Xn” for humidity.
For the fuser
28
/
28
′, let factors T3 be the response for a thermistor located a first edge of the heated fusing roller
66
and let T4 be the response for a thermistor in the center of the heated fusing roller.
For the Electrical Bias
416
, let factor F1=fuser electrical bias in standard units, e.g. volts.
For the Media Transport
417
, let factor S1=n, where n=1 for fast speed, n=2 normal speed, n=3 for slow speed.
To continue the example, assume nip bias pressure is a constant, if analysis determines:
P1=1
R1=1
R2=2
T1=2
T2=X
1
H1=X
2
T3<260° F.
T4<180° F.
then the controller sets:
E1 ON FULL
E2 ON HALF
S1=1
F1=−500V.
As another example, if analysis determines:
P1=2
R1=2
R2=3
T1=1
T2=X
1
H1=X
2
T3<260° F.
T4<180° F.
then the controller sets:
E1 ON FULL
E2 OFF
E3 ON FULL
S1=2
F1=−600 VOLTS.
It will be recognized by those skilled in the art of digital and analog controls for electromechanical systems that a number of other methodologies can be employed in accordance with the present invention.
Note that the memory used to store values can be active, namely refreshing its own look-up table data for particular media based on output characteristics of actual media employed by the end user under actual operating conditions.
As another specific example of fully automated operation, assume the printer
10
(
FIGS. 1
,
2
) is at a default setting, e.g., for standard #20 plain paper in input tray
20
most often used for printing. The ambient Environmental Sensor(s)
403
are providing the controller
30
with continual readings and the controller makes adjustments accordingly. Now assume, a standard, but relatively rough surfaced, Commercial #10 envelope is input to the printer
10
. Media type sensor
405
(
FIG. 4
) signals the change of media type to the controller
30
. The exact width and thickness are detected by Media Size sensor(s)
409
; namely, that it is a narrow, yet thicker media than the #20 plain paper. Since, the media is narrow, thus only a narrow cross fusing roller
66
heating profile is needed. The Media Characteristic(s) Sensor(s)
411
determine that the roughness is relatively high, that the moisture content is relatively low, and that the surface charge is highly negative. In such a case, the toner
61
(
FIG. 3
) will have a difficult time adhering since the surface charge is highly negative, the surface roughness is high, and the thickness is also high. Therefore, the controller
30
determines that there should be applied a higher than usual heat, a highly negative charge on the fusing roller
66
to repel the toner
61
and keep it pressed to the media, and the normal force can be adjusted to prevent thick, narrow media from being wrinkled. After the envelope exits the fuser
28
, assume the Print Sensors(s) detect low moisture content in the media, high curl, and good toner adhesion. Assuming the next sheet of media to be printed is another Commercial #10 envelope (or is detected
405
,
49
,
411
to have characteristics within the same tolerance band); based on this feedback from the Print Sensor(s)
421
, the controller
30
lowers the temperature slightly and the next sheet is printed and fixed accordingly.
In summary, this aspect of the present invention provides a print fusing subsystem (generally
FIG. 4
) in a hard copy apparatus
10
uses automated sensing devices
403
,
405
,
409
,
411
,
413
,
415
,
416
,
417
,
421
to provide current condition input signals and operational feedback signals to optimize (generally
FIG. 5
) the fusing subsystem operational parameters. Monitoring of ambient environmental conditions, subsystem operational parameters, and a print medium
18
from input
20
,
34
,
36
,
38
,
40
through output
44
,
46
,
16
, and the final printed text or image for predetermined characteristics is used to generate signals indicative of conditions that can be altered by commands to the fusing subsystem to optimize print quality.
EXPANDED SYSTEM EMBODIMENT
FIG. 7
is a schematic block diagram for the present invention in which the feedback from the sensors has been given an expanded roll in controlling various subsystems of the printer
10
to optimize process operational parameters.
In addition to controlling fuser
28
′ operational parameters as shown in
FIGS. 4 and 5
based on feedback from the plurality of sensors
403
,
405
,
409
,
411
,
421
, the “High Voltage Power Supply” (“HVPS”)
701
operation via the controller
30
can also benefit from sensor data feedback. Among other functions, the HVPS
701
controls the transfer voltage for the transfer drum
54
as previously described with respect to FIG.
3
. In the state of the art, the end-user has to know that the currently used media has, for example, a relatively high resistivity and then make manual adjustments to the transfer voltage bias via the control panel
14
(
FIG. 1
) to prevent print quality defects. As described with respect to
FIGS. 2-5
, printing operational parameters such as resistivity of the media are directly related to the electrophotography process voltage requirements.
Furthermore, the HVPS
701
controls the bias to electrostatic charge brushes and discharge brushes
70
,
72
in the paper path
32
(FIG.
3
). It will be recalled that the Media Characteristic(s) Sensor(s)
411
provides data regarding the charge of the media sheet.
An additional sensor, “Fuser Roller(s) Contamination Sensor(s),”
703
is provided to detect the presence of residual toner on one or both rollers
66
,
68
. Detail of a specific implementation is described in U.S. patent application Ser. No. 09/384,716, filed by co-inventor Martin et al., on Aug. 26, 1999, addresses issues with respect to METHOD AND APPARATUS FOR DETECTING IMAGE MEDIUM SURFACE DEFECTS IN AN IMAGING SYSTEM (assigned to the common assignee herein and incorporated herein by reference).
In the state of the art, media transport speed is generally set for a different fixed speed depending on the size and type of media being run through the printing cycle. Media throughput speed can be more closely controlled by any number of known manner devices such as automated multi-speed or variable speed transmission mechanisms (generically represented in
FIG. 7
by a box labeled “Throughput Speed Adjust”) being incorporated into the Media Transport controls
417
.
Two other sensor devices
705
,
707
are provided for inspecting the finished hard copy product output. After the media sheet has finished printing and is output into tray
16
(FIG.
1
), it can be inspected by optical sensing devices. For example, the IAS-1000, Automated Image Analysis System, manufactured by Quality Engineering Assoc, Inc. company of Burlington, Mass., might be adaptable for use in accordance with the present invention. Such optical sensing devices can be employed to recognize and provide feedback data to the controller
30
by sensing output print quality (“Final Output Print Quality Inspection Sensor(s)”
705
) or stacking problems (“Final Output Stacking Inspection Sensor(s)”
707
).
Additionally, the hard copy apparatus controller
30
sensor analysis component is provided with a routine for instigation of cleaning subsystems of the hard copy apparatus
10
. Specific embodiments are described in detail in U.S. patent application Ser. No. 09/384,716, filed by co-inventor Martin et al., on Aug. 26, 1999, addresses issues with respect to METHOD AND APPARATUS FOR DETECTING IMAGE MEDIUM SURFACE DEFECTS IN AN IMAGING SYSTEM (assigned to the common assignee herein and incorporated herein by reference). As other examples, a “Cleaning Page Print Job” option can be employed such as described in U.S. Pat. Appl. Ser. No. 09/584,019, filed by Roche for a CLEANING MEDIUM FOR INK-JET HARD COPY APPARATUS on May 30, 2000, or U.S. Pat. No. 5,589,865 by Beeson for an INKJET PAGE-WIDE-ARRAY PRINTHEAD CLEANING METHOD AND APPARATUS (each assigned to the common assignee herein and incorporated herein by reference). In essence, the action to be instigated is that when the sensor
703
determines the pressure roller
68
is dirty, a cleaning page command is issued and a special media to clean the roller is transported through the media path
32
accordingly.
EXPANDED SYSTEM OPERATIONS
FIG. 8
is a flow chart depicting typical operations of the system shown in FIG.
7
. Reader reference also to
FIGS. 2 and 3
in the course of the following description will be helpful. As can now be recognized, the plurality of sensors employed can have interactive feedback coordinated and controlled by the controller
30
.
As in
FIG. 5
, step
501
, at a power ON, the Environmental Sensor(s)
403
begin reporting the current ambient environmental conditions to the controller
30
sensor analysis component.
Fuser
28
′ sensors
413
,
415
,
416
,
703
begin sending data representative of the fuser current status conditions, step
801
.
Additionally, as in the embodiment of
FIG. 5
, via the control panel
14
, or via the host computer
407
(FIGS.
4
and
7
), the end-user may choose to input specific requirements that will override one or more sensor inputs, step
511
.
In the course of normal operations, the media sheet
18
enters the media path
32
, step
803
. The input sensors
405
,
409
,
411
examine the incoming sheet, step
805
. Data from the input sensors
405
,
409
,
411
is received by the controller
30
, analyzed, and optimal printing operational parameters are determined, step
807
.
The controller
30
determines and transmits various command functions, steps
807
,
808
,
809
,
810
,
81
1
, and
812
, as required for each controlled system, e.g., fuser
28
/
28
′, HVPS
701
, Media Transport
417
, or other printer subsystems so affected, based upon the feedback data. The operations are shown in parallel to once again indicate that the feedback data may have interactive implications which can be taken into account by the controller data analysis routines in reaching specific determinations as to optimal printing operation parameter adjustments.
The media sheet
18
is transported through the nip
62
between the imaging roller
52
and the transfer roller
54
, printing the current page image; the media sheet
18
continues through the nip
69
in the fuser
28
, fixing the image, step
813
.
Next, downstream of the fuser
28
/
28
′, the output sensors
421
,
705
,
707
examine the printed page. Data indicative of the printing operation results is fed back to the controller
30
, step
815
.
Note that when located immediately downstream adjacent to the fuser
28
/
28
′, the Print Sensor(s)
421
can provide nearly instantaneous feedback and dynamic adjustments can be made to the fuser
28
/
28
′for the current page being processed.
The process culminates
817
with optimum printing results due to the real time analysis of media characteristics and current operating and environmental conditions.
The foregoing description of the preferred embodiment of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. Similarly, any process steps described might be interchangeable with other steps in order to achieve the same result. The embodiment was chosen and described in order to best explain the principles of the invention and its best mode practical application, thereby to enable others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. While the present invention has been described with respect to a laser hard copy apparatus using commercial electrophotography toner developing processes, it will be recognized by those skilled in the art that the present invention is applicable to other hard copy apparatus, such as ink-jet printing technology, where a different wet colorant is used to form the alphanumeric text characters and graphic images. Moreover, the present invention is applicable to any printing process using a post-printing cycle print fixing process. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. Reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather means “one or more.” Moreover, no element, component, nor method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the following claims. No claim element herein is to be construed under the provisions of 35 U.S.C. Sec. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for . . . .”
Claims
- 1. A print fusing system, comprising:print fuser having a plurality of individually controllable heaters; a controller connected to said heaters; connected to said controller, at least one sensor for ambient environmental conditions, at least one sensor for media parameters, at least one sensor for current print fuser system conditions, such that signals from each said sensor to said controller are provided to said controller for adjusting fusing system conditions to optimal for the next media sheet passing therethrough; and override controls for providing input requirements that override one or more sensor input signals to the controller.
- 2. The system as set forth in claim 1, further comprising:connected to said controller, at least one print sensor for print quality detection such that a signal from said print sensor is provided to said controller for adjusting fuser system conditions to optimal for the next media sheet passing therethrough.
- 3. The system as set forth in claim 2, said at least one print sensor for print quality detection providing signals indicative of print quality characteristics comprising:an output sensor wherein said characteristics are selected from a group including media temperature, media deformation, and toner adhesion strength.
- 4. The system as set forth in claim 1, said at least one sensor for ambient environmental conditions comprising:a plurality of ambient environmental condition sensors including at least one temperature sensor and at least one humidity sensor.
- 5. The system as set forth in claim 1, said at least one sensor for media parameters comprising:at least one media type sensor.
- 6. The system as set forth in claim 1, said at least one sensor for media parameters comprising:at least one media size sensor.
- 7. The system as set forth in claim 1, said at least one sensor for media parameters comprising:at least one sensor for detecting media characteristics of a currently sensed sheet.
- 8. The system as set forth in claim 7, comprising:said media characteristics are selected from a group including texture, temperature, heat capacity, moisture content, thickness, resistivity, and latent electrical charge.
- 9. The system as set forth in claim 1, comprising:said controller is connected for receiving media size and type information from a host computer.
- 10. The system as set forth in claim 1, said at least one sensor for current fuser system conditions comprising:at least one temperature sensing and control device for each of said heaters.
- 11. The system as set forth in claim 1, said at least one sensor for current fusing system conditions comprising:at least one electrical potential sensing and control device for said fuser system.
- 12. The system as set forth in claim 1, said fuser including a mechanism for pressurizing a sheet of media passed through the fuser, said at least one sensor for current fusing system conditions comprising:at least one pressure sensing and control device.
- 13. A method for controlling hard copy apparatus' subsystems' printing operation parameters, via a hard copy apparatus controller, the method comprising:recognizing print medium characteristics during said medium input; recognizing said subsystems' printing operation parameters current states; based on said steps of recognizing print medium characteristics and recognizing said current states, commanding said subsystems to adjust printing operation parameters from said current states to adjusted states for optimizing print quality in accordance with said characteristics; recognizing print medium condition characteristic changes as said medium progresses along a media path through said apparatus, and commanding said subsystems to adjust printing operation parameters substantially continuously to the adjusted states for optimizing print quality in accordance with said characteristic changes.
- 14. The method as set forth in claim 13, the step of recognizing print medium characteristics as said medium is input comprising:actively sensing said characteristics, and providing signals indicative of said characteristics to said controller for performing the step of commanding.
- 15. The method as set forth in claim 14, the step of actively sensing said characteristics further comprising:sensing media type characteristics, media size characteristics, and media conditions.
- 16. The method as set forth in claim 13, the step of recognizing said subsystems' printing operation parameters current states comprising:recognizing current ambient environmental conditions.
- 17. The method as set forth in claim 16 comprising further:commanding said subsystems to adjust printing operation parameters for optimizing print quality in accordance with dynamic changes in said current ambient environmental conditions.
- 18. The method as set forth in claim 13 further comprising the steps of:recognizing current ambient environmental conditions as said medium progresses along a media path through said apparatus, and commanding said subsystems to adjust printing operation parameters substantially continuously to the adjusted states for optimizing print quality in accordance with dynamic changes in said current ambient environmental conditions.
- 19. The method as set forth in claim 13, the step of recognizing said subsystem's printing operation parameters current states comprising:substantially continually determining operational parameters associated with the current state of a high voltage power supply.
- 20. The method as set forth in claim 19, comprising the further steps of:monitoring an electrophotography transfer voltage, and adjusting said transfer voltage as said medium progresses along a media path through said apparatus for optimizing print quality in accordance with said characteristics.
- 21. The method as set forth in claim 19 comprising the further steps of:monitoring electrostatic charge conditions associated with said medium as said medium progresses along a media path through said apparatus, and adjusting electrical bias on devices for altering electrostatic charge conditions associated with said medium for optimizing print quality in accordance with said characteristics.
- 22. The method as set forth in claim 13, the step of recognizing said subsystem's printing operation parameters current states comprising:substantially continually determining operational parameters associated with throughput speed as said medium progresses along a media path through said apparatus.
- 23. The method as set forth in claim 22 comprising the step of:adjusting said throughput speed for optimizing print quality in accordance with said characteristics.
- 24. The method as set forth in claim 13, the step of recognizing said subsystem's printing operation parameters current states comprising:substantially continually determining operational parameters associated with fixing an image to said medium as said medium progresses along a media path through said apparatus.
- 25. The method as set forth in claim 24 comprising the step of:adjusting said operational parameters associated with fixing an image to said medium for optimizing print quality in accordance with said characteristics.
- 26. The method as set forth in claim 24 comprising the further step of:monitoring apparatus associated with the step of fixing an image for contamination of the apparatus, and commanding a cleaning cycle of said apparatus associated with the step of fixing when a predetermined threshold of contamination is exceeded.
- 27. A method for controlling hard copy apparatus'subsystems'printing operation parameters, via a hard copy apparatus controller, the method comprising:recognizing print medium characteristics during said medium input; recognizing said subsystems'printing operation parameters current states; based on said steps of recognizing print medium characteristics and recognizing said current states, commanding said subsystems to adjust printing operation parameters from said current states to adjusted states for optimizing print quality in accordance with said characteristics; outputting the medium having an image printed thereon; inspecting the medium with respect to post-printing characteristics; providing signals to said controller indicative of current post-printing characteristics; and commanding said subsystems to adjust printing operation parameters from said current states to adjusted states for optimizing print quality in accordance with said post-printing characteristics for a next sheet of medium to be printed.
- 28. A hard copy apparatus, having means for electrophotographically processing image printing data as a printed page and means for controlling the means for electrophotographically processing image printing data, including printing and media transport subsystems thereof, comprising:connected to the means for controlling, at least one sensor for ambient environmental conditions, at least one sensor for media parameters and at least one sensor for print quality characteristics, wherein signals from each said sensor to said means for controlling are provided to said means for controlling for determining and adjusting operational parameters of said means for electrophotographically process image printing data to optimal levels for printing the image data on a media sheet passing through said apparatus; wherein the at least one sensor for print quality characteristics comprises: sensors for providing signals indicative of post-printing characteristics of said printed page; and said characteristics are associated with both image quality and with medium condition.
- 29. The apparatus as set forth in claim 28, further comprising:at least one sensor for determining contamination levels of predetermined subsystems of said means for electrophotographically processing printing image data into a printed page, and the means for controlling further including means for commanding cleaning operations when said sensor for determining contamination levels indicates contamination levels exceeding a predetermined threshold.
- 30. The apparatus as set forth in claim 28, comprising:said controller provides commands for adjusting a high voltage power supply having controllable bias potential outputs associated with predetermined said subsystems of said means for electrophotographically processing printing image data into a printed page.
- 31. The apparatus as set forth in claim 28, comprising:said controller provides commands for adjusting media throughput speed devices associated with predetermined said subsystems of said means for electrophotographically processing printing image data into a printed page.
- 32. The apparatus as set forth in claim 28, comprising:said controller provides commands for adjusting operational parameters of fusing subsystems of said subsystems of said means for electrophotographically processing printing image data into a printed page.
- 33. The apparatus as set forth in claim 28, wherein the at least one sensor for print quality characteristics further comprises:sensors for providing signals indicative of current print medium characteristics selected from the group including media thickness, media texture, media surface charge, media temperature, media heat capacity, media thermal conductivity, media electrical resistivity, media latent charge, and media moisture content.
- 34. The apparatus as set forth in claim 28, comprising:said means for controlling processes signals from said at least one sensor for ambient environmental conditions, at least one sensor for media parameters and at least one sensor for print quality characteristics in a determinatively interactive manner such that commands are sent by said means for controlling to electrophotographic processing subsystems of said apparatus substantially in real time, setting optimal levels for printing the image data on a current media sheet passing through said apparatus.
- 35. A memory device having a program for controlling electrophotography device subsystems comprising:computer code enabling the recognition of signals indicative of print media characteristics, signals indicative of printed image characteristics, and signals indicative of current electrophotography device subsystems operational parameters; computer code determining optimal electrophotography device subsystems operational parameters based upon analysis of said signals indicative of print media characteristics and signals indicative of printed image characteristics; computer code commanding adjustments to the electrophotography device subsystems operational parameters based upon the analysis of said signals indicative of print media characteristics and signals indicative of printed image characteristics; and computer code analyzing signals indicative of post-printing image quality and post-printing media condition characteristics.
- 36. The device as set forth in claim 35, further comprising:computer code enabling the recognition of signals indicative of current ambient environmental conditions affecting print quality; and computer code commanding adjustments to the electrophotography device subsystems operational parameters based upon the analysis of said signals indicative of the current ambient environmental conditions.
- 37. The device as set forth in claim 35, comprising:computer code analyzing signals indicative of current print medium characteristics selected from the group including media thickness, media texture, media surface charge, media temperature, media heat capacity, media thermal conductivity, media electrical resistivity, media latent electrical charge, and media moisture content.
- 38. The device as set forth in claim 35, the computer code commanding adjustments to the electrophotography device subsystems operational parameters further comprising:computer code routines selected from the group including computer code for controlling image fusing subsystems, computer code for controlling high voltage biases to apparatus subsystems, and computer code for controlling apparatus subsystems associated with throughput.
- 39. A hard copy apparatus, having means for electrophotographically processing image printing data as a printed page and means for controlling the means for electrophotographically processing image printing data, including printing subsystems and media transport subsystems thereof, comprising:connected to the means for controlling, at least one sensor for ambient environmental conditions, at least one sensor for media parameters, and at least one sensor for print quality characteristics, wherein signals from each said sensor to said means for controlling are provided to said means for controlling for determining and for adjusting operational parameters of said means for electrophotographically process image printing data to optimal levels for printing the image data on a media sheet passing through said apparatus, and wherein said means for controlling processes signals from said at least one sensor for ambient environmental conditions, from said at least one sensor for media parameters, and from said at least one sensor for print quality characteristics in a determinatively interactive manner such that commands are sent by said means for controlling to electrophotographic processing subsystems of said apparatus substantially in real time, setting optimal levels for printing the image data on a current media sheet passing through said apparatus.
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