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CROSS REFERENCE
Cross reference is made to U.S. patent application Ser. Nos. 08/315,021;
08/315,173; 08/315,277; 08/315,274; D/94194; and D/94688.
The present invention is directed to an improving facsimile transmission in
multifunction devices, and more particularly to an automated system useful
in multifunction devices for efficiently transmitting facsimile documents
from a networked facsimile device.
BACKGROUND OF THE INVENTION
Standard facsimile devices which operate only as facsimile machines
connected directly to a telephone line are rapidly being replaced by
devices which combined facsimile and/or digital scanning, copying and
printing in one single unit. Note, e.g., U.S. Pat. No. 4,947,345 to
Paradise; U.S. Pat. No. 3,597,071 to Jones; U.S. Pat. No. 5,038,218 to
Matsumoto; U.S. Pat. No. 5,021,892 to Kita, et al.; and U.S. Pat. No.
4,623,244 to Andrews, et al. Such devices can take advantage of network
connections so that they can be effectively used by a wide group of users
as a department printer or facsimile machine. Even in such an environment
however, a single multifunction machine will continue to have only a
single or, at most, a limited number of external telephone ports.
When a multifunction machine is utilized by a significant number of users,
the probability of more than one individual directing a job (some work
process utilizing copying, printing, scanning or transmitting capability
of the device) to the machine is greatly increased, requiring a method of
handling the queue of multiple jobs that is formed. There are many ways to
prioritize queues, based on time of receipt, job-type, available
resources, user codes, etc. U.S. Pat. No. 4,947,345 to Paradise, et al.
shows one prioritization scheme, which assumes that facsimile messages are
usually very important and should receive high priority in the job queues
requiring utilizing the printer.
Generally speaking, transmission of documents across networks utilized by
remote terminals are known, for example, as shown by examples of recent
patents relating to network environments of plural remote terminals shared
by users, including but not limited to Xerox Corporation U.S. Pat. No.
5,243,518; U.S. Pat. No. 5,226,112; U.S. Pat. No. 5,170,340 and U.S. Pat.
No. 5,287,194. Some patents on this subject by others include U.S. Pat.
No. 5,113,355, U.S. Pat. No. 5,113,494 (originally filed Feb. 27, 1987),
U.S. Pat. No. 5,181,162, U.S. Pat. No. 5,220,674, U.S. Pat. No. 5,247,670;
U.S. Pat. No. 4,953,080 and U.S. Pat. No. 4,821,107. Further, by way of
background, some of the following Xerox Corporation patents also include
examples of networked systems with printers: U.S. Pat. No. 5,153,577; U.S.
Pat. No. 5,113,517; U.S. Pat. Nos. 5,072,412; 5,065,347; 5,008,853;
4,947,345; 4,939,507; U.S. Pat. No. 4,937,036; U.S. Pat. No. 4,920,481;
U.S. Pat. No. 4,914,586; U.S. Pat. No. 4,899,136; U.S. Pat. No. 4,063,220;
U.S. Pat. No. 4,099,024; U.S. Pat. No. 3,958,088; U.S. Pat. No. 3,920,895;
and U.S. Pat. No. 3,597,071. Also noted are IBM Corp. U.S. Pat. No.
4,651,278 and U.S. Pat. No. 4,623,244 (both assigned to IBM), and U.S.
Pat. No. 4,760,458 and Japanese Pub. No. 59-63872 published Nov. 4, 1984
(both assigned to Canon). Some of these various above patents also
disclose multi-functional or integral machines [digital
scanner/facsimile/printer/copiers] and their controls.
Some other network systems related publications include "Xerox System
Integration Standard Printing Protocol XSIS 118404", April 1984; "Xerox
Integrated Production Publishers Solutions: . . . " Booklet No.
"610P50807" "11/85"; "Printing Protocol-Xerox System Integration Standard"
.COPYRGT.1990 by Xerox Corporation, XNSS 119005 May 1990; "Xerox Network
Systems Architecture", "General Information Manual", XNSG 068504 April
1985, with an extensive annotated bibliography, .COPYRGT.1985 by Xerox
Corporation; "Interpress.TM.: The Source Book", Simon & Schuster, Inc.,
New York, N.Y., 1988, by Harrington, S. J. and Buckley, R. R.; Adobe
Systems Incorporated "PostScript.RTM. Language Reference Manual",
Addison-Wesley Co., 1990; "Mastering Novell" Netware.RTM., 1990, SYBEX,
Inc., Alameda, Calif., by Cheryl E. Currid and Craig A. Gillett;
"Palladium Print System" .COPYRGT.MIT 1984, et sec; "Athena85" "Computing
in Higher Education: The Athena Experience", E. Balkovich, et al,
Communications of the ACM, 28(11) pp. 1214-1224, November, 1985; and
"Apollo87" "The Network Computing Architecture and System: An Environment
for Developing Distributed Applications", T. H. Dineen, et al, Usenix
Conference Proceedings, June 1987.
Noted among commercial network systems with printers and software therefor
is the 1992 Xerox Corporation "Network Publisher" version of the 1990
"DocuTech.RTM." publishing system, including the "Network Server" to
customer's Novell.RTM. 3.11 networks, supporting various different network
protocols and "Ethernet.TM."; and the Interpress Electronic Printing
Standard, Version 3.0, Xerox System Integration Standard XNSS 048601
(January 1986). Also, the much earlier Xerox Corporation "9700 Electronic
printing System"; the "VP Local Laser Printing" software application
package, which, together with the Xerox "4045" or other Laser
Copier/Printer, the "6085" "Professional Computer System" using Xerox
Corporation "ViewPoint" or "GlobalView.RTM." software and a "local printer
[print service] Option" kit, comprises the "Documenter" system. The even
earlier Xerox Corporation "8000" "Xerox Network Services Product
Descriptions" further describe other earlier Xerox Corporation electronic
document printing systems. Eastman Kodak "LionHeart.TM." systems, first
announced Sep. 13, 1990, are also noted. Current popular commercial
published "systems software" including LAN workstation connections
includes Novell.RTM. DOS 7.0, "Windows.TM." NT 3.1, and IBM OS/2 Version
2.1. Also noted in the Xerox 7033 LAN FAX server, a facsimile machine with
a network connection serving multiple workstations on a LAN network.
U.S. Pat. No. 5,287,194 to Lobiando suggests the desirability of allocating
printing jobs to printers on a network based on a function related to job
length and queue length. The arrangement assumes that the user has access
to the locations at which the printing will occur. Also noted is U.S. Pat.
No. 5,128,878 to Gore et al, detailing a scheduling system which utilizes
multiple plotters in a network.
As facsimile jobs become longer and more numerous due to the increased
reliability and availability of facsimile devices, the facsimile
transmission function of a multifunction machine or facsimile machine is
"busy" for longer periods of time. Depending on usage, queues of facsimile
jobs will be created, causing delays in the transmission of any particular
job as it works its way through the queue, even though users will believe
that the job was sent. However, U.S. Pat. No. 4,947,345 to Paradise, et
al. does not address the problem of long waits to send facsimile jobs,
even assuming that facsimile jobs are given high priority.
Common practice provides that a user seeking to send a document to a remote
location facsimile must positively select which facsimile machine to use
to send the document. However, a user really has little interest in which
machine actually transmits the document.
References disclosed herein are incorporated by reference for their
teachings.
SUMMARY OF THE INVENTION
The present invention is directed to a networked facsimile system, in which
a plurality of networked facsimile devices exchange facsimile jobs in
their respective queues, to optimize outgoing transmission of facsimile
documents.
In accordance with one aspect of the invention, a plurality of
multifunction devices each having a facsimile function are connected
together in a networking arrangement. Upon receipt of a job requiring a
facsimile function, such a device initially checks its queues to determine
whether there are any current facsimile jobs in the queues which would
delay the transmission of the just-received document. If there are none,
the document is transmitted in accordance with the device job priority
control arrangement. If prior facsimile jobs are present in the queue, the
device checks, via its network connection, other networked devices having
facsimile capability from a preprogrammed list thereof, to determine
whether any of the devices are not busy. In such a case, the job, with
facsimile control instruction and data, is transferred to the non-busy
facsimile for transmission.
In accordance with another aspect of the invention, in a system as
described, if all of the networked devices are determined to be busy, a
second level inquiry is performed to determine the shortest queue. Upon
determining that any queue is shorter than the queue of the original
device, the job, with facsimile control instruction and data, is
transferred to the non-busy facsimile for transmission.
These and other aspects of the invention will become apparent from the
following description, the description being used to illustrate a
preferred embodiment of the invention when read in conjunction with the
accompanying drawings.
FIG. 1 is a block diagram depicting a multifunctional, network adaptive
printing machine;
FIG. 2 is a block diagram of a video control module for the printing
machine of FIG. 1;
FIG. 3 is a block diagram of a transfer module used in conjunction with the
printing machine of FIG. 2;
FIG. 4 is a block diagram of a facsimile card used in conjunction with the
printing machine of FIG. 2;
FIG. 5 is a block diagram of a network controller for the printing machine
of FIG. 1;
FIG. 6 is a block diagram representing a subsystem of the printing machine
of FIG. 2; and
FIG. 7 is a flow chart showing a preferred mode of operation for the
present invention.
While the present invention will hereinafter be described in connection
with a preferred embodiment thereof, it will be understood that it is not
intended to limit the invention to that embodiment. On the contrary, it is
intended to cover all alternatives, modifications and equivalents as may
be included within the spirit and scope of the invention as defined by the
appended claims.
Referring to FIG. 1, a multifunctional, network adapted printing system is
designated by the numeral 10. The printing system 10 includes a printing
machine 12 operatively coupled with a network service module 14. The
printing machine 12 includes an electronic subsystem 16, referred to as a
video control module (VCM), communicating with a scanner 18, a printer 20
and an external telephone line 21. In one example, VCM 16, which will be
described in further detail below, coordinates the operation of the
scanner and printer in a digital copying arrangement. In one possible
scanning arrangement, scanner 18 (also referred to as image input terminal
(IIT)) reads an image on an original document by using a CCD full width
array and converts analog video signals, as gathered, into digital
signals. In turn, an image processing system 22 (FIG. 2), associated with
scanner 18, executes signal correction and the like, converts the
corrected signals into multi-level signals (e.g. binary signals),
compresses the multi-level signals and preferably stores the same in
electronic precollation (EPC) memory 24.
Referring again to FIG. 1, printer 20 (also referred to as image output
terminal (IOT)) preferably includes a xerographic print engine. In a
printing context, multi-level image data is read out of the EPC memory 24
(FIG. 2) for printing. It will be appreciated by those skilled in the art
that the printer can assume other forms besides a xerographic print engine
without altering the concept upon which the disclosed embodiment is based.
For example, the printing system 10 could be implemented with a thermal
ink jet or ionographic printer.
Referring specifically to FIG. 2, the VCM 16 is discussed in further
detail. The VCM 16 includes a video bus (VBus) 28 with which various I/O,
data transfer and storage components communicate. Preferably, the VBus is
a high speed, 32 bit data burst transfer bus which is expandable to 64
bit. The 32 bit implementation has a sustainable maximum bandwidth of
approximately 60 MBytes/sec. In one example, the bandwidth of the VBus is
as high as 100 MBytes/sec.
The storage components of the VCM reside in the EPC memory section 30, mass
memory section 32 and heap memory 116. The EPC memory section includes the
EPC memory 24, the EPC memory being coupled with the VBus by way of a DRAM
controller 33. The EPC memory, which is preferably DRAM, provides
expansion of up to 64 MBytes, by way of two high density 32 bit SIMM
modules. The mass memory section 32 includes a SCSI hard drive device 34
coupled to the VBus by way of a transfer module 36a. As will appear, other
I/O and processing components are coupled respectively to the VBus by way
of transfer modules 36. It will be appreciated that other devices (e.g., a
workstation) could be coupled to the VBus by way the transfer module 36a
through use of a suitable interface and a SCSI line.
Referring to FIG. 3, the structure of one of the transfer modules 36 is
discussed in further detail. The illustrated transfer module of FIG. 3
includes a packet buffer 38, a VBus interface 40 and DMA transfer unit 42.
The transfer module 36, which was designed with "VHSIC" Hardware
Description Language (VHDL), is a programmable arrangement permitting
packets of image data to be transmitted along the VBus at a relatively
high transfer rate. In particular, the packet buffer is programmable so
that the segment or packet can be varied according to the available
bandwidth of the VBus. In one example, the packet buffer can be programmed
to handle packets of up to 64 Bytes. Preferably, the packet size would be
reduced four times when the VBus is relatively busy and increased for
times when activity on the bus is relatively low.
Adjustment of the packet size is achieved with the VBus interface 40 and a
system controller 44 (FIG. 5). Essentially, the VBus interface is an
arrangement of logical components, including, among others, address
counters, decoders and state machines, which provides the transfer module
with a selected degree of intelligence. The interface 40 communicates with
the system controller to keep track of desired packet size and, in turn,
this knowledge is used to adjust the packet size of the packet buffer 38,
in accordance with bus conditions. That is, the controller, in view of its
knowledge regarding conditions on the VBus 28, passes directives to the
interface 40 so that the interface can adjust packet size accordingly.
Further discussion regarding operation of the transfer module 36 is
provided below.
More particularly, the DMA transfer unit employs a conventional DMA
transfer strategy to transfer the packets. In other words, the beginning
and end addresses of the packet are used by the transfer unit in
implementing a given transfer. When a transfer is complete, the interface
40 transmits a signal back to the system controller 44 so that further
information, such as desired packet size and address designations, can be
obtained.
Referring to FIGS. 1 and 2, three I/O components are shown as being coupled
operatively to the VBus 28, namely a FAX module 48, the scanner or IIT 18,
and the printer or IOT 20; however, it should be recognized that a wide
variety of components could be coupled to the VBus by way of an expansion
slot 50. Referring to FIG. 4, an implementation for the FAX module, which
is coupled to the VBus 28 by way of transfer module 36b, is discussed in
further detail. In the preferred embodiment, a facsimile device (FAX) 51
includes a chain of components, namely a section 52 for performing Xerox
adaptive compression/decompression, a section 54 for scaling compressed
image data, a section 56 for converting compressed image data to or from
CCITT format, and a modem 58, preferably manufactured by Rockwell
Corporation, for transmitting CCITT formatted data from or to a telephone,
byway of conventional telephone line 21.
Referring still to FIG. 4, each of the sections 52, 54 and 56 as well as
modem 58 are coupled with the transfer module 36b by way of a control line
60. This permits transfers to be made to and from the FAX module 48
without involving a processor. As should be understood, the transfer
module 36b can serve as a master or slave for the FAX module in that the
transfer module can provide image data to the FAX for purposes of
transmission or receive an incoming FAX. In operation, the transfer module
36b reacts to the FAX module in the same manner that it would react to any
other I/O component. For example, to transmit a FAX job, the transfer
module 36b feeds packets to the section 52 through use of the DMA transfer
unit 42 and, once a packet is fed, the transfer module transmits an
interrupt signal to the system processor 44 requesting another packet. In
one embodiment, two packets are maintained in the packet buffer 38 so that
"ping-ponging" can occur between the two packets. In this way, the
transfer module 36b does not run out of image data even when the
controller cannot get back to it immediately upon receiving an interrupt
signal.
Referring again to FIG. 2, the IIT 18 and IOT 20 are operatively coupled to
the VBus 28 by way of transfer modules 36c and 36d. Additionally, the IIT
18 and the IOT 20 are operatively coupled with a compressor 62 and a
decompressor 64, respectively. The compressor and decompressor are
preferably provided by way of a single module that employs Xerox adaptive
compression devices. Xerox adaptive compression devices have been used for
compression/decompression operations by Xerox Corporation in its
DocuTech.RTM. printing system. In practice, at least some of the
functionality of the transfer modules is provided by way of a 3 channel
DVMA device, which device provides local arbitration for the
compression/decompression module.
As further illustrated by FIG. 2, the scanner 18, which includes the image
processing section 22, is coupled with an annotate/merge module 66.
Preferably, the image processing section includes one or more dedicated
processors programmed to perform various desired functions, such as image
enhancement, thresholding/screening, rotation, resolution conversion and
TRC adjustment. The selective activation of each of these functions can be
coordinated by a group of image processing control registers, the
registers being programmed by the system controller 44. Preferably, the
functions are arranged along a "pipeline" in which image data is inputted
to one end of the pipe, and image processed image data is outputted at the
other end of the pipe. To facilitate throughput, transfer module 36e is
positioned at one end of the image processing section 22 and transfer
module 36c is positioned at another end of the section 22. As will appear,
positioning of transfer modules 36c and 36e in this manner greatly
facilitates the concurrency of a loopback process.
Referring still to FIG. 2, arbitration of the various bus masters of the
VCM 16 is implemented by way of a VBus arbiter 70 disposed in a VBus
arbiter/bus gateway 71. The arbiter determines which bus master (e.g., FAX
module, Scanner, Printer, SCSI Hard Drive, EPC Memory or Network Service
Component) can access the VBus at one given time. The arbiter is made up
of two main sections and a third control section. The first section, i.e.,
the "Hi-Pass" section, receives input bus requests and current priority
selection, and outputs a grant corresponding to the highest priority
request pending. The current priority selection input is the output from
the second section of the arbiter and is referred to as "Priority Select".
This section implements priority rotation and selection algorithm. At any
given moment, the output of the logic for priority select determines the
order in which pending requests will be serviced. The input to Priority
Select is a register which holds an initial placement of devices on a
priority chain. On servicing requests, this logic moves the devices up and
down the priority chain thereby selecting the position of a device's next
request. Control logic synchronizes the tasks of the Hi-Pass and the
Priority Select by monitoring signals regarding request/grant activity. It
also prevents the possibility of race conditions.
Referring to FIG. 5, the network service module 14 is discussed in further
detail. In a preferred embodiment, the controller 44, which preferably
assumes the form of a SPARC processor, manufactured by Sun Microsystems,
Inc., is coupled with a standard SBus 72. In the illustrated embodiment of
FIG. 5, a host memory 74, which preferably assumes the form of DRAM, and a
SCSI disk drive device 76 are coupled operatively to the SBus 72. While
not shown in FIG. 5, a storage or I/O device could be coupled with the
SBus with a suitable interface chip. As further shown in FIG. 5, the SBus
is coupled with a network 78 by way of an appropriate network interface
80. In one example, the network interface includes all of the hardware and
software necessary to relate the hardware/software components of the
controller 44 with the hardware/software components of the network 78. For
instance, to interface various protocols between the network service
module 14 and the network 78, the network interface could be provided
with, among other software, Netware.RTM. from Novell Corp. The arrangement
enables the transfer of jobs and status information via the network.
In one example, the network 78 includes a client, such as a workstation 82
with an emitter or driver 84. In operation, a user may generate a job
including a plurality of electronic pages and a set of processing
instructions. In turn, the job is converted, with the emitter, into a
representation written in a page description language, such as PostScript.
The job is then transmitted to the controller 44 where it is interpreted
with a decomposer, such as one provided by Adobe Corporation. Some of the
principles underlying the concept of interpreting a PDL job are provided
in U.S. application Ser. No. 07/898,761 entitled "Apparatus and Method for
Multi-Stage/Multi-Process Decomposing", filed on Jun. 12, 1992, by Bonk et
al., and U.S. Pat. No. 5,226,112 to Mensing et al., the pertinent portions
of both references being incorporated herein by reference. Further details
regarding a technique for generating a job in a PDL may be obtained by
reference to the following text, the pertinent portions of which are
incorporated herein by reference to "PostScript.RTM. Language Reference
Manual", Second Edition, Addison-Wesley Publishing Co. (1990)
Referring again to FIG. 2, the network service module 14 is coupled with
the VCM 16 via a bus gateway 88 of the VBus arbiter/bus gateway 71. In one
example, the bus gateway comprises a field programmable gate array
provided by XILINX corporation. The bus gateway device provides the
interface between the host SBus and the VCM VBus. It provides VBus address
translation for accesses to address spaces in the VBus real address range,
and passes a virtual address to the host SBus for virtual addresses in the
host address range. A DMA channel for memory to memory transfers is also
implemented in the bus gateway. Among other things, the bus gateway
provides seamless access between the VBus and SBus, and decodes virtual
addresses from bus masters, such as one of the transfer modules 36, so
that an identifier can be obtained from a corresponding slave component.
It will be appreciated by those skilled in the art that many components of
the printing system 10 are implemented in the form of a single ASIC.
Referring to FIGS. 2, 3 and 5, further discussion regarding DMA transfer of
each of the transfer modules 36 is provided. In particular, in one
example, the images of a job are stored in the host memory 74 as a series
of blocks. Preferably, each block comprises a plurality of packets. In
operation, one of the transfer modules 36 is provided, by the controller
44, with the beginning address of a block and the size of the block. In
turn, for that block, the transfer module 36 effects a packet transfer and
increments/decrements a counter. This procedure is repeated for each
packet of the block until the interface 40 determines, by reference to the
counter, that the last packet of the block has been transferred.
Typically, for each stored image, several blocks are transferred, in a
packet-by-packet manner, as described immediately above.
Referring to FIG. 6, a model of facsimile operation is provided, designated
by the numeral 100. Facsimile system 100, which is suitable for acquiring,
and processing a job comprising job attribute information and image data,
and transmitting the job in a facsimile format, includes a job acquisition
section 102, an image processing service 104, a video service 106, and a
fax service 108. Each of the system components 102, 104, 106 and 108
communicates with a job manager or job process 110. The job manager 110
communicates with a job database ("db") 112. The job acquisition
preferably includes a user interface ("UI") 114 (FIG. 2), for providing
attributes of the job, and one of, among other sources, the scanner 18
(FIG. 1), the workstation 82 (FIG. 5), the fax module 51 (FIG. 4) or other
suitable input source, such as a floppy disk or CD-ROM (neither shown),
for providing image data of the job.
Preferably, the attributes of the job, such as job level instructions
(e.g., destination phone number), page level instructions (e.g., plex and
processing related instructions) and other characteristics (sheet size,
collation, security) are programmed with the UI 114 (FIG. 2), which UI is
coupled with the VBus 28 by way of a suitable UI interface 116. Any
suitable UI, such as the UI used with the DocuTech.RTM. printing system,
would be appropriate for use as UI 114. With a UI, such as the one used by
the DocuTech.RTM., job attributes are set in a dialog or job ticket by way
of keyboard input or a curser (e.g., "Mouse") technique. A job ticket
suitable for use in the present embodiment is disclosed in U.S. Pat. No.
5,271,065 to Rourke et al., the pertinent portions of which are
incorporated herein by reference.
The image processing service 104 includes the image processing section 22
(FIG. 2) and an image processing reference system 120. Preferably, the
reference system includes one of plural tools necessary to estimate the
time required to perform a given image processing operation, such as
resolution conversion or image rotation, for a given image. In one
example, the reference system 120 comprises a look up table mapping image
size with one of plural image processing operations. In another example,
an "intelligent" or heuristic algorithm, exploiting experiential data
collected by the printing system for previously performed image processing
operations is used to provide an estimate for each page to be image
processed in the image processing section 22.
The video service 106 includes the compression service 62, the
decompression service 64 and the reference system 122. As with the
reference system 120, the reference system 122 can use, among other
approaches, a look-up table, mapping uncompressed image data quantity
against compressed quantity, or an intelligent algorithm in which the
reference system determines the compressed size of a given page based on
the degree to which the video service has compressed previous pages of
comparable size.
The facsimile service 108 includes the facsimile function 51.
The concept of using icons to represent respective facsimile machines on a
local area network, with attendant printing properties is embodied in a
Xerox.RTM. network printing system incorporating, among other components,
a 6085 or SunSparc.RTM. workstation, Viewpoint.RTM. software and a
suitable network facsimile machine. Additionally, the facsimile service
includes a facsimile manager for controlling the facsimile process of the
one or more suitable print engines.
Job manager 110 provides the "brain power" required to obtain a facsimile
job ETC. The job manager comprises a process capable of calculating ETCs
for each page. The methodology used by the job manager to obtain job ETCs
will be discussed in further detail below. The job manager is also
responsible for maintaining the database 112. As with the DocuTech
printing system, images are stored in memory, such as the EPC memory
24/SCSI Disk 34 and corresponding image identifiers are stored in the
database 112. Also, as with the DocuTech printing system, the image
identifiers are used during printing to retrieve selected stored images.
As further discussed below, the database 112 is employed to store page and
job ETCs.
The present estimating technique contemplates at least two approaches for
displaying Job ETC. In one approach, certain defaults in the process cause
the Job ETC to be displayed after selected events. For example, as
indicated above, the Job ETC is displayed automatically after the ETC
database is updated in view of consulting the image processing/video
services. In some cases, however, a user may wish to have the current Job
ETC displayed periodically. In this event, an update timer (not shown) can
be activated so that the current Job ETC is displayed periodically on the
screen associated with the UI 114 (FIG. 2). The timer can be inactivated
so that the only default displays are provided.
Assuming that an image processing or compression operation is performed,
one or both of the reference systems 120, 122 is consulted and, in
response to such consulting, the Job ETC is, via step 156, updated. In one
example, selected pages of the job are to be image processed and
compressed. For each one of the selected pages the appropriate look-up
table or algorithm is referenced and the associated Page ETC is updated.
After each Page ETC is updated, the Job ETC is updated and if viewing of
the updated Job ETC is desired a display of the current Job ETC is
provided, via a screen associated with the UI 114 (FIG. 2).
Alternatively, ETC can be calculated only as a function of the number of
jobs entering the facsimile queue. Upon entering the queue, JOB ETC is
incremented, thereby indicating the ETC is greater.
The system 10 is capable of storing multiple jobs, by way of a queue. More
particularly, referring to FIG. 2, information regarding each stored job
is preferably stored in a job or heap memory 164, the heap memory
comprising suitable nonvolatile memory coupled with the VBus 28 by way of
a suitable heap memory control or interface 166. Further details regarding
queue systems suitable for use in a digital printing systems may be
obtained by reference to U.S. Pat. No. 5,206,735. In practice the queue,
which includes at least two types of information, namely the Job ETC for
each stored job and a cumulative time, i.e., a "System ETC", required to
process the stored jobs, is displayed on the screen associated with the UI
114. It will be appreciated that these times would be adjusted
appropriately in accordance with job interrupts of the type discussed in
U.S. Pat. No. 5,206,735. By "process", we refer to the processing required
to prepare a document received from a given source for output to a
particular system device, and to actually output the document. In the case
of a facsimile job, this might include, for example, an estimate of time
required to decompose a PDL-described document to a bitmap suitable for
facsimile transmission, an estimate for establishing a handshake with an
external receiving facsimile device, and an estimated transmission time at
an optimum compression ratio.
Referring now to FIG. 7, an exemplary method of operation of the present
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