Title: Printer controller, printing system, and recording medium therefor
Abstract: The invention provides a printer controller capable of ensuring printing data without deteriorating a performance of the printer without provision of a storage means for storing printing data in the controller. The controller receives printing data for each page from a host, transfers the printing data to a printer and controls the printer to print the printing data while monitoring states thereof, wherein the controller comprises: an analyzing unit that analyzes the printing data and manages the number of pages transferred to the printer; and an error processing unit that informs error data and the number of pages of which printing have been completed to the host when an error in which data is not assured occurs in the printer.
Patent Number: 6,967,743 Issued on 11/22/2005 to Kumazawa
| Inventors:
|
Kumazawa; Masaru (Kawasaki, JP)
|
| Assignee:
|
Fujitsu Limited (Kawasaki, JP)
|
| Appl. No.:
|
212393 |
| Filed:
|
December 16, 1998 |
Foreign Application Priority Data
| Jun 30, 1998[JP] | 10-184195 |
| Current U.S. Class: |
358/1.9; 358/1.14; 358/468 |
| Intern'l Class: |
G06K 015/00 |
| Field of Search: |
358/19,114,115,116,326,426.02,426.11,468,443,448,471
|
References Cited [Referenced By]
U.S. Patent Documents
| 6078400 | Jun., 2000 | Mizutani.
| |
| 6122073 | Sep., 2000 | Miyasaka.
| |
| Foreign Patent Documents |
| 2-217281 | Aug., 1990 | JP.
| |
| 9-114618 | May., 1997 | JP.
| |
| 9-198203 | Jul., 1997 | JP.
| |
Primary Examiner: Grant, II; Jerome
Attorney, Agent or Firm: Westerman, Hattori, Daniels & Adrian, LLP
Claims
1. A controller that receives printing data for each page from a host, having
a data transferring unit that transfers the printing data to a printer without
having a storage unit for storing the printing data in the controller when printing
is resumed after an error has occurred in the printer and controls the printer
to print the printing data while monitoring states thereof is characterized in
that it comprises:
an analyzing unit that analyzes the printing data and manages the number of pages
transferred to the printer; and
an error processing unit that passes error data and the number of pages of which
printing have been completed to the host when an error occurred in the printer,
wherein said analyzing unit is provided with a plurality of analyzing units corresponding
to different types of printers, and one of the analyzing units is selected corresponding
to the type of printer connected to the controller.
2. A controller according to claim 1 wherein,
said controller further comprises a preset data storage unit that stores preset
data of printers to be connected to the controller,
said analyzing unit and said error processing unit execute the respective processes
based on the preset data of a printer currently connected to the controller which
is stored in the preset data storage unit.
3. A controller according to claim 1 wherein,
said controller further comprises a printer recognizing unit that inquires and
recognizes functions of the printer connected to the controller,
said analyzing unit and said error processing unit execute the respective processes
based on the functions of a printer currently connected to the controller recognized
by the printer recognizing unit.
4. A recording medium readable by computers on which programs are recorded which
enable a computer to process the steps of receiving printing data for each page
from a host, transferring the printing data to a printer and controlling the printer
to print the printing data while monitoring states thereof, is characterized in that:
said programs enable said computer to function as an analyzing unit that analyzes
the printing data and manages the number of pages transferred to the printer; and
an error processing unit that informs error data and the number of pages of which
printing have been completed to the host when an error occurs in the printer;
wherein the printer does not have a storage unit for storing the printing data
when printing is resumed after an error has occurred in the printer,
wherein said analyzing unit is provided with a plurality of analyzing units corresponding
to different types of printers, and one of the analyzing units is selected corresponding
to the type of a printer connected to the controller.
5. A recording medium readable by computers on which programs are recorded which
enable a computer to proceed the steps of receiving printing data for each page
from a host, transferring the printing data to a printer and controlling the printer
to print the printing data while monitoring states thereof, is characterized in that:
said programs enable said computer to function as an analyzing unit that analyzes
the printing data and manages the number of pages transferred to the printer; and
an error processing unit that informs error data and the number of pages of which
printing have been completed to the host when an error occurs in the printer; and
wherein said analyzing unit is provided with a plurality of analyzing units corresponding
to different types of printers, and one of the analyzing units is selected corresponding
to the type of a printer connected to the controller.
6. A recording medium readable by computers on which programs are recorded which
enable a computer to process the steps of receiving printing data for each page
from a host, transferring the printing data to a printer and controlling the printer
to print the printing data while monitoring states thereof, is characterized in that:
said programs enable said computer to function as an analyzing unit that analyzes
the printing data and manages the number of pages transferred to the printer; and
an error processing unit that informs error data and the number of pages of which
printing have been completed to the host when an error occurs in the printer;
wherein said analyzing unit is provided with a plurality of analyzing units corresponding
to different types of printers, and one of the analyzing units is selected corresponding
to the type of a printer connected to the controller.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a printer controller, a printing system and
a recording medium therefor and, in particular, it relates to a printer controller,
a printing system and a recording medium which can realize minimum double printing
and data assured printing, without deteriorating a performance of the printer,
even if a printer incapable of transmitting a print completed signal is used and
an error such as a paper jam occurs in the printer.
2. Description of the Related Art
In general, a printer controller is provided between a host which requests printing
and a printer. The controller receives printing data transmitted from the host
and transfers the data to the printer and controls the printer to print while monitoring
the states of the printer.
In the prior art, if a printer incapable of transmitting data containing an error
signal and printer state data to the controller or the host is used, when an error
such as a paper shortage in a paper-cassette, a paper jam or a power failure has
occurred, the controller works as below.
The controller judges whether data can be transferred by checking that power
has been supplied to the printer, stops the data transfer when an printer error
has been detected during transferring data and resumes the data transfer after
the error has been corrected.
When an error in the printer is detected during transferring data, the controller
sends a command to initialize the printer and resumes printing for each file.
When assuring the printing data, in other words, when checking whether the printing
data is recoverable and not missed, a feed completion wait command, namely, a command
for making the printer wait to respond to the data transfer of the next page until
the printer completes feeding the printed paper, is added to the printing data.
Printing systems in the prior art pose several problems that cause abnormal
printing such as data skip, page skip, character change and the like when an error
has occurred in the printer and the printing is resumed after the error has been
corrected. For example,
(1) When consecutive printing data is transferred after a power supply to the
printer is recovered after the power supply turned off during printing, namely,
after the printer becomes ready for printing after the power turned off.
(2) When consecutive printing data is transferred after a paper jam has been
corrected after the jam occurred during printing.
In addition, when a command for making the printer wait until the printer completes
feeding the printed paper is added, data transfer of the next page cannot be started
for printing because the printer waits for a response to the transferring data
of the next page until the printer completes feeding the printed paper. Thus, such
a printing system in prior art as explained above poses a problem in that a decrease
in performance in continual printing, as compared with normal printing, occurs
because the mechanical performance of the printer cannot be fully utilized.
In order to solve the above problems, a printer controller comprising a storage
means for storing printing data and a managing means for managing printed pages
with the use of the storage means is disclosed in Japanese Patent Publication No.
2-217281 and No. 9-114618, wherein Japanese Patent Publication No. 2-217281 requires
retransmission from a host to the controller while Japanese Patent Publication
No. 9-114618 does not require the same for error recovery. According to the technique
of these disclosed controllers, the number of printed pages can be managed and
error recovery can be accomplished. However, the controllers require a storage
means for storing printing data, thus the controllers cannot be made compact or economical.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to solve the above
problems and provide a printer controller, a printer system and a recording medium
for the same, without providing a storage means for storing printing data, and
capable of realizing minimum page skipping and minimum double printing and capable
of assuring printing data without deteriorating the performance of the printer
when the printing is resumed after an error has been corrected.
A printer controller according to the present invention which solves the above
problems, receives printing data for each page from a host, transfers the printing
data to a printer and controls the printer to print the printing data while monitoring
states thereof.
The printer controller is characterized in that it comprises: an analyzing unit
that analyzes the printing data and manages the number of pages transferred to
the printer; and an error processing unit that informs error data and the number
of pages of which printing has been completed to the host when an error in which
data is not assured occurred in the printer.
A printing system according to the present invention comprises a host, a controller
and a printer controlled by the controller. The host comprises a function to analyze
printing data and a function to manage the printing data for each page. The controller
comprises an analyzing unit, an error processing unit, a printer recognizing unit,
a set data storage unit, and a data transferring unit.
Each unit in the controller executes the following processes:
(1) The analyzing unit analyzes the printing data transmitted from the host and
manages the number of pages transferred to the printer.
(2) The error processing unit monitors the states of the printer and executes
a process of error data informed from the printer. For example, when an error in
which data is not guaranteed occurs in the printer, the unit informs the error
data and the number of pages of which printing has been completed by the time when
the error occurred, to the host.
The host transmits printing data of which printing has not yet completed to the
controller, and makes it possible to re-print for each file based on the information
informed from the controller, after the printer has recovered, by correcting the error.
(3) The preset data storage unit stores preset data of the printer connected
to the controller. The analyzing unit and the error processing unit execute the
respective processes with the use of the preset data.
(4) The preset data storage unit can also store preset data of the printer informed
from the host. The analyzing unit and the error processing unit execute the respective
processes in accordance with a function of the printer informed from the host and
stored in the preset data storage unit.
(5) The printer recognizing unit recognizes types, functions and the like of
the printer connected to the controller by testing the printer. The analyzing unit
and the error processing unit execute the respective processes in accordance with
the function of the printer stored in the preset data storage unit and recognized
by the recognizing unit.
(6) The data transferring unit transfers printing data to the printer.
(7) A plurality of analyzing units may be provided, each corresponding to each
type of printer connected to the recognizing unit in the controller which is recognized
by the recognizing unit, and one of the analyzing units is selected according to
the type.
(8) In case a printer incapable of transmitting a paper feeding completion signal
is connected to the controller, the error processing unit estimates the number
of pages of which printing has completed based on the mechanical function of the
printer and transmits the estimated number of pages with error data to the host.
According to the present invention, which solves the aforementioned problems,
a printing system is provided which comprises a host, a controller that receives
printing data for each page transmitted from the host and a printer that receives
the printing data from the controller and carries out printing while monitoring
the states of the printer by the controller, is characterized in that: said controller
comprises, an analyzing unit that analyzes the printing data and manages the number
of pages transferred to the printer, and an error processing unit that informs
error data and the number of pages of which printing has been completed to the
host when an error in which data is not assured occurred in the printer, wherein
when an error occurs in the printer, said host transmits printing data of which
printing has not been completed to the controller based on data informed by the
controller after the printer is recovered by correcting the error, said controller
transfers said printing data to the printer and controls the printer to carry out
re-printing for each page.
According to the present invention which solves the aforementioned problems,
a recording medium is provided which is readable by computers on which programs
are recorded which enable a computer to proceed the steps of receiving printing
data for each page from a host, transferring the printing data to a printer and
controlling the printer to print the printing data while monitoring states thereof,
is characterized in that: said programs enable said computer to function as an
analyzing unit that analyzes the printing data and manages the number of pages
transferred to the printer; and an error processing unit that informs error data
and the number of pages of which printing have been completed to the host when
an error in which data is not assured occurred in the printer.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more clearly understood from the description as
set forth below with reference to the accompanying drawings, wherein:
FIG. 1 is a general constitutional view showing a printing system of an embodiment
of the present invention;
FIG. 2 is a view for explaining a constitution of the controller shown in FIG. 1;
FIG. 3 is a view showing a format of a printing data stream transmitted from
the host to the controller, both shown in FIG. 1;
FIG. 4 is a view showing a format of a printing data stream transmitted from
the controller to the host, both shown in FIG. 1;
FIG. 5 is a flowchart showing a routine for setting a type of a printer connected
to the controller, both shown in FIG. 1;
FIG. 6 is a view showing a printing data management table;
FIG. 7 is a view for explaining details of printing time assigned to a page printer;
FIG. 8A is a view showing an example of a parameter table related to paper sizes
for various kinds of printers;
FIG. 8B is a view showing another example of a parameter table related to cassette
locations for various kinds of printers;
FIG. 9 is a flowchart showing a routine for data transfer from the controller
to the printer, both shown in FIG. 1;
FIG. 10A is a flowchart (in a normal condition) showing a routine for counting
the number of normally printed sheets by a controller to which a second type printer
having no function of informing the print completion signal, is connected;
FIG. 10B is a flowchart showing a timer interrupting routine related to FIG. 10A;
FIG. 10C is a flowchart (in a normal condition) showing a routine for counting
the number of normally printed sheets by a controller to which a first type printer,
having a function of informing the print completion signal, is connected;
FIG. 11A is a flowchart (when an error has occurred) showing a routine for counting
the number of normally printed sheets by a controller;
FIG. 11B is a flowchart showing a timer interrupting routine related to FIG. 11A;
FIG. 12A is a flowchart (when double-sided printing is executed) showing a routine
for counting the number of normally printed sheets by a controller;
FIG. 12B is a flowchart showing a timer interrupting routine related to FIG. 12A;
FIG. 13 is an example of a timechart showing a data transfer from a controller
to a page printer when a plurality of pages are continuously printed;
FIG. 14 is another example of a timechart showing a data transfer from a controller
to a page printer when a plurality of pages are continuously printed;
FIG. 15A is a flowchart showing a routine for counting the number of normally
printed sheets by a page printer when a plurality of pages are continuously printed; and
FIG. 15B is a flowchart showing a timer interrupting routine related to FIG. 15A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will be described below with
reference to the accompanying drawings.
FIG. 1 is a general constitutional view showing a printing system of an embodiment
of the present invention. In FIG. 1,
10 denotes a host that requests printing,
20 denotes a controller and
30 denotes a printer. The host
10
and the controller
20 are connected via a Local Area Network (LAN)
40.
The controller
20 and the printer
30 are connected with a cable
50
in accordance with the Centronics interface (I/F). A plurality of hosts
10
can be connected to the controller
20 via the LAN
40.
The host
10 comprises functions to analyze the printing data and to manage
printed data for each page. The host
10 transmits printing data of which
printing has not yet been completed to the controller
20 and makes the controller
20 resume the recovery printing in which the printing data to be transmitted
from the host
10 is determined based on an error data informed from the
printer
30 via the controller
20, or an error data detected by the
controller
20 and informed to the host
10 although the printer
30
is incapable of transmitting the error data, and the number of normally printed
pages by the printer
30 which is calculated by the controller
20.
When printing is requested from the host
10, the controller
20
receives the printing data, analyzes data and transfers the data to the printer
30 for printing.
When an error such as a paper jam has occurred in the printer, the controller
recognizes the error data of the printer at that time which indicates the number
of print completed pages and etc., calculates the number of pages of which printing
have completed, and informs the same to the host
10. After the error of
the printer
30 is removed, the controller
20 informs to the host
10 that the error is corrected. Then, the host
10 resumes printing
for each page for the uncompleted pages.
FIG. 2 is a view for explaining a constitution of the controller shown in FIG. 1.
The controller
20 comprises a network control unit
21, a plurality
of printing data analyzing units
22-i (i=1 to N), a preset data storage
unit
23, a data transferring unit
24, an error processing unit
25
and a Centronics I/F unit
26.
The network control unit
21 comprises a receiving buffer
21a
and a transmitting buffer
21b, thereby receiving data transmitted
from the host
10 and transferring the data to the analyzing unit
22,
and transmitting error data and/or print completion signal to the host
10.
The printing data analyzing unit
22 consists of a plurality of printing
data analyzing units
22-
1 to
22-N, each adapted to each different
kind of printer so that a plurality of data types such as languages supported by
the printers can be handled. A printing data analyzing unit
22-i (i=1 to
n) adapted to a language supported by the printer
30 is selected based on
the model name of the printer
30 obtained from the printer
30 or
the printing data.
When the controller
20 receives printing data transmitted from the host
10, the data is passed to the printing data analyzing unit
22-i,
and the unit
22-i analyzes the data. By this analysis, the page end, namely,
data amount per page, size of printing papers, currently used cassette location
when a paper feeding unit consisting of a plurality of cassettes for stocking printing
papers is used, and printing control data indicating, for example, whether or not
double-sided printing is requested, are obtained.
The data transferring unit
24 determines interval of the data transfer
for each page based on the printing control data obtained by the analyzing units
22-i and the model name of the printer
30 connected to the controller
20.
The Centronics I/F unit
26 transfers printing data to the printer
30
and recognizes a state of the printer
30 and acquires a nibble mode of the
IEEE-1284 interface and the device ID (identification) number. In case printers
in which the nibble mode is supported are connected to the controller, detail error
data and the number of print completed pages can also be acquired.
The error processing unit
25 converts error data acquired via the Centronics
I/F unit
26 from the printer
30 to an error code for transmitting
it to the host
10 via the transmitting buffer
21B. The error processing
unit
25 also judges whether the error data transferred from the printer
is assured or not. The assured error data herein means printing data which does
not require retransmission from the host
10 because the printing data is
recoverable and not missed, while non-assured error data means printing data which
need retransmission from the host
10.
In case the error is not an assured one, the error processing unit
25
commands
the printer
30 to erase printing data and calculates and obtains the number
of normally printed pages, and transmits the error code, the number of normally
printed pages and a flag indicating that the printing data is not assured (guaranteed),
to the host
10 via the transmitting buffer
21b.
When the host
10 receives the number of normally printed pages and the
flag indicating that the printing data is not assured, the host retransmits the
uncompleted printing data to the printer
30 via the controller
20.
After setting a network environment setting, for example, an IP address setting
from the host
10, has completed in accordance with the TELENET protocol
supported by the controller, a model name and the function level settings of the
printer
30, and customizing data settings which can be set by users, the
preset data storage unit
23 stores the above set data into a non-volatile
memory such as EEPROM.
FIG. 3 is a view showing a typical format of a printing data stream transmitted
from the host
10 to the controller
20, both shown in FIG. 1.
Data assigned as interface data between the host
10 and the controller
20 in a network as shown in FIG. 3, which is data for a proper protocol
used for communication between the host
10 and the controller
20,
and is necessary data for the host
10, like "host defined printer name"
or the like, is set.
In the main part, printing data to be actually transferred to the printer
30
are assigned in such a format as "printing control data such as a paper size and
a cassette location", "character data to be printed" and so on in series for each
page. As shown in FIG. 3, "a page end mark" is attached to each end of the printing
data for each page.
FIG. 4 is a view showing a typical format of a printing data stream transmitted
from the controller
20 to the host
10, both shown in FIG. 1. As shown
in FIG. 4, the format includes a "header", an "error code" indicating error data
in a printer, "the number of printed pages" indicating the number of normal print
completed pages and a "flag" indicating whether the error in the printer
30
is recoverable or requires retransmission of the printing data.
When an error requiring retransmission of the printing data occurs in the printer
30, the number of normal print completed pages is set in the part of "the
number of printed pages" and "1" is set in the "flag" indicating that retransmission
of the printing data is required, then the data stream is transmitted to the host
10.
FIG. 5 is a flowchart showing a routine for setting a type of a printer connected
to a controller.
In steps S
1, the controller
20 judges whether or not the power
is
supplied to the printer
30. If the result in step S
1 is YES, the
controller
20 sends a request command to the printer
30 in order
to acquire the device ID of the printer in step S
2. In step S
3, whether
or not the printer
30 has responded to the request command in step S
2
is checked. If the result in step S
3 is YES, the controller
20 sets
the model name of the printer
30 in accordance with the device ID reported
by the printer
30 in step S
7.
In case the printer
30 does not respond to the request command in step
S
3, it can be judged that the printer is not the type which conforms to
the IEEE-1284 I/F so that the process proceeds steps S
4 to S
8 to
acquire the type of the printer. In step S
4, the controller
20 judges
whether or not a request for printing is transmitted from the host
10, if
the result is YES, step S
5 proceeds, and if the result is NO, the routine
ends. In step S
5, it is judged whether or not the host defined printer name
set in accordance with the interface data between the host
10 and the controller
20 in printing data in response to the print command, as explained with
reference to FIG. 3, can be acquired, namely, it is judged whether or not the printer
model name set by the host can be acquired. If the result is YES, step S
8
proceeds to acquire the printer type set by the host. If the result is NO, step
S
6 proceeds to acquire the printer name stored in the preset data storage
unit
23.
In addition to the routine explained above, if a printer name acquired from the
host
10 different from a printer name acquired from the printer
30,
the controller
20 passes a setting error to the host
10.
If a host incapable of setting the host defined printer name is used, since the
value is not set in the field of the host defined printer name in the printing
data, a device model name stored in the preset data storage unit
23 is used.
After the printer name is determined by executing the routine explained above,
the analyzing unit
22 takes out the printing data received via the communication
line out of the receiving buffer, and analyzes the printing data based on the determined
type of the printer and manages the data for each page.
FIG. 6 is a view showing a printing data management table. The printing data
analyzing unit
22 generates the table in which each printing data is assigned
for each page as shown in FIG. 6 after the printing data from the host
10
is received in the buffer
21b. Then the data divided into pages and
managed by the analyzing unit
22 are passed to the data transfer controller
24, and the data are transferred to the printer
30 via the Centronics
I/F controller
26.
The calculating unit for calculating the number of print completed pages executes
different routines depending upon the three different types of the printers as
described below.
(First Type): Printers capable of informing the number of normal print completed
pages in accordance with the nibble mode of IEEE-1284.
(Second Type): Printers such as a laser beam page printer incapable of informing
the number of normal print completed pages in accordance with the nibble mode of IEEE-1284.
(Third Type): Printers such as line printers, serial printers and multi-purpose
printers, incapable of informing the number of normal print completed pages in
accordance with the nibble mode of IEEE-1284.
In the first type of printers, the number of normal paper feeding completion
pages
can be acquired by checking data from the printer when the error is informed from
the printer.
In the third type printers such as a line printer having only a line buffer,
normal
paper feeding completion can be acquired by confirming the completion of transferring
data indicating page end because the printer has only the line buffer for the temporarily
storing printing data for a few lines.
On the other hand, in case of the second type of printers such as a page printer,
even if page end data is transferred, it is not always the case that the page has
completely printed since printing data for a plurality of pages can be buffered
in the printer. Because of this, the controller monitors printing time and estimates
the completion time of normal printing. Namely, as the printer does not inform
the print completion, the controller presets an imaginary time for paper feeding
completion and regards that the normal printing has completed when the error has
not been informed from the printer for a period of the preset time.
FIG. 7 is a view for explaining details of printing time assigned to the second
type of printers, for example, page printers.
In case of the second type of printers, the printing speed, the number of pages
printed per minute (ppm) of each printer is known as a mechanical performance.
As apparent from FIG. 7, the timer monitoring time corresponding to the imaginary
time for paper feeding completion can be given by the following equation.
wherein the data handling time is a period started from the completion timing
of the data transfer from the printer controller
20 to the printer
30
and is handled by the printer, the data handling time is set to "0" except for
particular data types, and the mechanical start up time is set to "0" except for
the first printing page.
FIG. 8A is a view showing an example of a parameter table to obtain respective
mechanical start up time and paper feeding time related to paper sizes for various
kinds of printers, and FIG. 8B is a view showing another example of a parameter
table to obtain respective delay time related to cassette locations for various
kinds of printers. In these tables, measured values or calculated values are preset.
The timer monitoring time can be given by the following equation,
As an example, assuming that the printer type, MODEL 1, is connected to the printer
controller
20, paper size A4 is used, and one page is printed by using papers
stocked in the No. 2 cassette, the timer monitoring time is given by (t
1+t
1X+t
1B).
FIG. 9 is a flowchart showing a routine for data transfer from a controller
to a printer.
First, in step S
1, printing data is analyzed in the printing data analyzing
unit
22. In step S
2, the page data is acquired. Next, in step S
3,
whether or not the printer
30 connected to the printer controller
20
is the first type is checked. If the result is YES, namely, if the printer
30
is the first type, the routine ends. If the result is NO, the process proceeds
to step S
4. In step S
4, whether or not the printer
30 is the
second type such as a page printer is checked. If the result is YES, namely, if
the printer
30 is the second type, the process proceeds to step S
5.
If the result is NO, namely, if the printer is the third type, the routine ends.
If the printer
30 is the second type, for example, a page printer, whether
or not the double-sided printing is designated or not is checked in step S
5.
If the result is NO, the paper feeding time for the single-side printing is obtained
with reference to the table as shown in FIG. 8A in step S
6. If the result
is YES, the paper feeding time is obtained with reference to a similar table to
that shown in FIG. 8A in which paper feeding time for the double-sided printing
is preset in step S
7.
Next, in step S
8, the delay time in the cassette is read from the table
as shown in FIG. 8B. In step S
9, whether or not the first print for the
page is checked. If the result is YES, the process proceeds to step S
10.
In step S
10, the mechanical start up time is read from the table as shown
in FIG. 8A. If the result is NO, the process proceeds to step S
11. In step
S
11, the data transfer unit
24 transfers printing data for a page
to the printer
30 via the Centronics I/F unit
26. In step S
12,
the timer monitoring time is calculated based on the equation explained before.
In step S
13, the timer is started to complete the process.
FIGS. 10A,
10B,
10C,
11A,
11B,
12A and
12B
are flowcharts showing a routine for counting the number of normally printed sheets
in a normal condition executed by the controller
20 according to an embodiment
of the present invention.
FIG. 10A is a flowchart showing a first routine for counting the number of normally
printed sheets in a normal condition when the second type printer is connected
to the controller, and FIG. 10B is a flowchart showing a timer interrupting routine
triggered by the first routine.
In FIG. 10A, in step S
1, the print data analyzing unit
22 transfers
the printing data for each page from the data transfer unit
24 to the printer
30 via the Centronics I/F controller
26 in which the printing data
is transmitted from the host
10 and received by the network control unit
21. In step S
2, the analyzing unit
22 increases the number
of pages transferred as the printing data by one. The process calculates the monitoring
timer as explained before in step
53, and sets the timer for the interrupting
routine in step S
4.
When the monitoring time has passed while the printer
30 did not generate
any error, the timer interruption routine shown in FIG. 10B, is started. In step
56, the number of normally printed sheets is increased by one.
In step S
5, whether or not printing data for the next page is prepared
is checked, if the result is YES, the process returns to step S
1 and repeats
steps S
1 to
55. If the result is NO, the process ends.
FIG. 10C is a flowchart showing a second routine for counting the number of
normally printed sheets in normal condition when the first type printer is connected
to the controller.
In FIG. 10C, steps S
1, S
2 and S
5 are the same as those in
FIG. 10A. Thus, the explanation is omitted and only steps S
3 and S
4
will be explained below. In step S
3, whether or not the printing has been
completed is checked, if the result is YES, the process proceeds to step S
4,
if the result is NO, the process returns to step S
3. In step S
4,
the number of normally printed sheets is increased by one.
FIG. 11A is a flowchart showing a third routine for counting the number of normally
printed sheets in case an error has occurred, and FIG. 11B is a flowchart showing
a timer interrupting routine triggered by the third routine.
In FIG. 11A, steps S
1, S
2, S
3 and S
4 are the same
as those in FIG. 10A. Thus, the only steps S
5 to S
11 will be explained
below. In step
55, whether or not the monitoring time has passed without
receiving any error from the printer
30 is checked. If the result is YES,
the process proceeds to step S
7, if the result is NO, the process proceeds
to step S
6. In step S
6, whether or not printing data for the next
page is prepared is checked. If the result is YES, the process returns to step
S
1 and steps S
1 to S
6 are repeated. If the result is NO, the
process proceeds to step S
7. In step S
7, an error report data is
generated and the number of normally printed sheets is acquired.
If the Centronics interface interruption is triggered by an error in the printer
before the monitoring time has passed, the timer interruption routine as shown
in FIG. 11B, is started.
In step
58, the error processing unit
25 checks whether or not
the
printing data is assured, if the result is YES, step S
9 proceeds. If the
result is NO, step S
10 proceeds. In step S
9, an error report data
in an error code is generated, and transmits the error code to the host
10.
In step S
10, a command to erase the printing data is given to the printer
30, the number of normally printed sheets is acquired, and the above number
of normally printed sheets and a flag indicating a command for request to retransmit
the printing data, are transmitted to the host
10, along with the error
code. In step S
11, a paper feeding completion monitoring timer is canceled,
if the timer is set.
FIG. 12A is a flowchart showing a fourth routine for counting the number of
normally printed sheets in normal condition and double-sided printing is selected
when the second type printer is connected, and FIG. 12B is a flowchart showing
a timer interrupting routine triggered by the fourth routine.
In FIG. 12A, in step S
1, the print data analyzing unit
22 transfers
the printing data for each two pages from the data transfer unit
24 to the
printer
30 via the Centronics I/F controller
26 in which the printing
data is transmitted from the host
10 and received by the network control
unit
21. In step S
2, the analyzing unit
22 increase the number
of pages transferred as the printing data by two. The process calculates the monitoring
timer in step S
3, and sets a timer for interruption in step S
4, as
explained before.
When the monitoring time has passed without receiving any error from the printer
30, the timer interruption routine shown in FIG. 12B, is started. In step
S
6, the number of normally printed sheets is increased by two.
In step S
5, whether or not printing data for the next page is prepared
is checked, if the result is YES, the process returns to step S
1 and steps
S
1 to S
5 are repeated, if the result is NO, the process ends.
As explained above, when the double-sided printing is executed, the number of
normally printed sheets is monitored for each two pages, in which a first page
for one side of a sheet, a second page for the other side of the sheet. Thus, the
number of normally printed pages reported to the host
10 is always even.
FIG. 13 is an example of a timechart showing a data transfer from a controller
to a page printer when a plurality of pages are continuously printed, and FIG.
14 is another example for the same.
In FIGS. 13 and 14, black star marks indicate transfer end timing and white star
marks indicate paper pick-up timing, wherein the paper pick-up means a motion to
bring a sheet of paper to the position to start printing after picking up the paper
from a cassette in which printing papers are stocked. In FIGS. 13 and 14, T
1
indicates a period from the transfer end timing to the paper feed end timing which
is monitored by the paper feeding completion monitoring timer, and T
2 indicates
a period from the start timing of paper feeding to the paper pick-up timing which
is monitored by the next page data transfer start monitoring timer.
FIG. 13 shows an example of the timechart in which the paper feeding of the
previous paper has not yet completed when a data transfer from a controller to
a page printer has completed. In FIG. 13, the timer for counting T
1 time
and the timer for counting T
2 time start counting when the data transfer
for one page to the printer has completed. Note that T
2 in the first page
printing is longer by the delay time of the cassette as compared with T
3
for paper pick-up in the second page printing in the continuous printings.
The data transfer for the second page starts just after the pick-up for the first
page has completed. Just after the data transfer for the second page has completed,
the T
2 timer starts counting. After the third page, the data transfer starts
if the paper feeding for previous page but one has been completed after the paper
pick up has completed.
In this way, data transfer starts with the completion of the paper feeding for
the previous page but one. Thus, the printer can avoid over flow of the buffer
and can avoid miscapture of the error data when an error occurred in the printer.
Furthermore, the number of errors in calculating the number of printed pages of
which paper feeding has completed, can be reduced.
FIG. 14 shows an example of the timechart in which the paper feeding of the
previous paper has completed when a data transfer from a controller to a page printer
has completed. As shown in FIG. 14, when the paper feeding for the previous page
has been completed as shown in the third page printing, when the data transfer
has just completed, the paper feeding completion monitoring timer T
1 indicating
a period from the transfer end timing to the paper feed end timing and the next
page data transfer start monitoring timer T
2 indicating a period from the
start timing of paper feeding to the paper pick-up timing are respectively set
by adding the first print delay time since the printer mechanically stops. Note
that the time period T
2 to pick up paper for the first and the third pages
are longer by the first print delay time in the cassette as compared to T
3
to pick up paper for the second and the fourth pages during continuous printing
is executed as shown in FIG. 14.
FIG. 15A is a flowchart showing a fifth routine by the controller for counting
the number of normally printed sheets printed by a page printer when a plurality
of pages are continuously printed, and FIG. 15B is a flowchart showing a timer
interrupting routine triggered by the fifth routine.
First of all, in step S
1, whether or not the data transfer monitoring
timer T
2 for the previous page but one is counting is checked. If the result
is YES, step S
1 is repeated. If the result is NO, the process proceeds to
step S
2. In step S
2, the printing data for one page is transferred
to the printer
30. Then, in step S
3, the number of printing data
transferred pages is increased by one.
In step S
4, whether or not the data transfer is for one page is checked.
If the result is YES, step S
6 proceeds. If the result is NO, step S
5
proceeds. In step S
5, whether or not the data transfer monitoring timer
T
2 for the previous page has been timed up is checked. If the result in
step S
5 is YES, a step S
6 proceeds. If the result in step S
5
is NO, step S
7 proceeds. In step S
6, the first print delay time in
the cassette is read from the table as shown in FIG. 8A.
Next, in step S
7, the monitoring time is calculated in accordance with
the equation explained before. In step S
8, the interruption timer is started.
In step S
9, whether or not the printer error has occurred is checked. If
the result is YES, the process proceeds to step S
11. If the result is NO,
the process proceeds to step S
10. In step S
10, whether or not printing
data for the next page has been prepared is checked, if the result is YES, the
process returns to step S
1 and steps S
1 to S
10 are repeated,
if the result is NO, the process proceeds to step S
11. In step S
11,
an error report is generated and the number of the normally printed pages is acquired.
When the monitoring time passes the preset time while the printer
30
does not generate any error, the timer interruption routine as shown in FIG. 15B,
is started. In step S
12, the number of normally printed sheets is increased
by one.
The parameter table for monitoring printing time and used for calculating the
number of normally printed sheets based on the paper size and the parameter table
for calculating the delay time based on the cassette locations explained before
are stored in the setting data storing unit. Data stored in these tables can be
changed from the host
10 with the use of the function of TELENET supported
by the printer controller
20.
Next, installation of programs of the invention will be described below. The
printer controller
20 as shown in FIG. 2 comprises a CPU, a ROM, a RAM,
an I/O interface and the like. Programs to make the controller
20 function
as the network control unit
21, the printing data analyzing unit
22,
the set data storing unit
23, the data transfer unit
24, the error
processing unit
25 and the Centronics I/F unit
26 are run by the
CPU, and the programs are stored in the ROM in advance and are written from the
ROM to the RAM when the CPU runs the programs. These programs can be processed
by a typical data processing system such as a personal computer or a workstation
of which hardware consists of a CPU, an RAM as a main storage means, a hard disk
as an auxiliary storage means, a display unit, a printer, an input device such
as a keyboard and the like.
When installing the programs of the invention into such a computer system, the
programs are recorded onto a portable recording medium such as a floppy disc or
an optical disc, for example, a CD-ROM, in advance. The programs are loaded onto
the main memory (RAM) in the computer system by means of a floppy disc drive or
a CD-ROM drive. The programs may be directly written onto the memory with the use
of the keyboard by operators. The programs can also be installed from a partner
computer connected to the computer employed via a modem over telephone networks
or via a terminal adapter over LANs. In this case, the programs may be installed
to the auxiliary storage in the computer employed from a recording medium in the
partner computer via the networks. The CPU writes the data installed in the auxiliary
storage to the main memory, if necessary, and run the programs.
As heretofore explained, the printer controller according to the present invention
is advantageous in the following points.
(1) The printer controller can minimize page skip and double printing when printing
is resumed after an error occurred in a printer without providing a storage means
for storing printing data, and can avoid the deterioration of the performance of
the printer and can assure the printed data.
(2) Since the printer controller has a preset data storage unit for storing information
of the printer connected to the printer controller and a plurality of analyzing
units corresponding to different kinds of printers, the controller can properly
work corresponding to functions of the printers connected thereto.
(3) Since the number of print completed pages is calculated based on the printing
performance of the connected printer, even if a printer incapable of reporting
the completion of paper feeding is connected, the printer controller can transfer
the number of print completed pages to the host, and can avoid page skip and double
printing, and can control the printer to reprint for each page.
It will be understood by those skilled in the art that the foregoing descriptions
are preferred embodiments of the disclosed printer controller and that various
changes and modifications may be made in the invention without departing from the
spirit and scope thereof.
*
