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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a printer for printing bit images
according to data input from a data processor such as a host computer.
2. Description of the Prior Art
As is well known, data sent from a data processor to a printer are
comprised of image code data for bit map images to be printed out and
control data for controlling the print method and mode of a print engine
of the printer. A controller of the printer processes image code data to
be transformed into bit map images to be printed out and sends bit images
to the print engine. In a conventional printer utilizing the
electro-photographic process, the printing operation thereof is stopped
when a trouble such as a paper jam is caused. Upon restarting the printer
after removing the cause of the trouble, it is needed to switch on the
power source for the printer or to operate a reset button therefor. Thus,
once a trouble is caused, data having been stored in the printer are
automatically erased. Therefore, the data have to be input again from the
external data processor into the printer.
This invites a considerable time loss to restart the printer since it
becomes necessary to wait completion of data transmission from the
external data processor to the printer.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a printer being capable
of restarting the printing operation thereof without data transmission
from an external data processor after recovery from a trouble state.
Another object of the present invention is to provide a printer having at
least one memory means for storing data regarding at least one page in
printing from which the stored data can be read out in order to restart
the printing operation after recovery from a trouble.
In order to achieve these objects, according to the present invention,
there is provided a printer comprising: a receipt means for receiving code
data indicating printing information and control information sent from an
external apparatus; an analysis means for analyzing received code data; a
first memory means for storing resultant data obtained by the analysis
means; an output means for outputting print data to a printing section of
the printer in accordance with said resultant data memorized in said first
memory means; a signal generation means for generating a signal indicating
a predetermined state when the printing section falls thereinto; a second
memory means for memorizing format information regarding at least one page
including the page being in printing; a control means for stopping
operation of said printing section when said signal is generated by said
signal generation means and restarting said printing operation of the
printing section in accordance with the format information memorized in
said second memory means when said predetermined state is dissolved.
When the printer falls into a predetermined state such as a trouble state,
the signal generation means generates a signal indicating the
predetermined state. Due to this signal, the control means stops the
printing operation of the printer and, when the predetermined state is
dissolved, restarts the printing operation according to data memorized in
respective memory means.
According to another aspect of the present invention, there is provided a
printer comprising: a receipt means for receiving code data indicating
printing information and control information sent from an external
apparatus; a first memory means for memorizing received code data; an
analysis means for analyzing said code data memorizing in said first
memory means; a second memory means for memorizing resultant data obtained
by said analysis means; an output means of outputting printing data to a
printing section of the printer in accordance with said resultant data
memorized in said second memory means; a signal generation means for
generating a signal indicating a predetermined state when the printing
section falls thereinto; a third memory means for memorizing format
information regarding at least the page in printing said third memory
means being connected to said analysis means; and a control means for
stopping printing operation of said printing section when said signal is
generated by said signal generation means and restarting said printing
operation of the printing section in accordance with the format
information memorized in said third memory means when said predetermined
state is dissolved.
In the printer resultant data obtained by the analysis means are stored in
the second memory means and, when the printer is recovered from the
predetermined state, they are read out from the second memory means to
form bit images according to the format information memorized in the third
memory means. Therefore, the printer can restart the printing operation
regarding the page suspended temporarily.
According to a further aspect of the present invention, there is provided a
printer comprising: a receipt means for receiving code data indicating
printing information and control information sent from an external
apparatus; a first memory means for memorizing received code data; an
analysis means for analyzing said code data memorized in said first memory
means; a second memory means for memorizing resultant data obtained by
said analysis means; an output means for outputting printing data to a
printing section of the printer in accordance with said resultant data
memorized in said second memory means; a signal generation means for
generating a signal indicating a predetermined state when said printing
section falls thereinto; a third memory means for memorizing format
information regarding at least a page in printing, said third memory means
format information analyzed by said analysis means; and a control means
for stopping the printing operation of said printing section when said
signal is generated an restarting the printing operation of said printing
section in accordance with the format information memorized in said third
memory means when said predetermined state is dissolved.
In the printer the third memory means memorizes format information having
been analyzed by the analysis means and, accordingly, resultant data
stored in the second memory means can be directly transformed into bit
images according to the analyzed format information.
BRIEF DESCRIPTION OF DRAWINGS
These and other objects and features of the present invention will become
more apparent when the preferred embodiment of the present invention is
described in detail with reference of accompanied drawings in that;
FIG. 1 is a block diagram of an electro-photographic printer system to
which the present invention is applied;
FIG. 2 is a perspective view of the printer system according to the present
invention;
FIG. 3 is a plan view of an operation panel of the printer;
FIG. 4 is a block diagram showing structures of a bit map type data
processor and a print engine of the printer system according to the
present invention;
FIG. 5 is a block diagram of the bit map controller;
FIG. 6 shows compositions of MCB buffer (a), MCB (b) and R-buffer (c);
FIG. 7 is a block diagram of a bit map writer according to the present
invention;
FIG. 8 is a system composition of first information processor (second
information processor);
FIG. 9 is a plan view showing an image area of a print;
FIG. 10 is a flow chart of the main routine to be executed by the first
information processor;
FIG. 11 is a flow chart of MCB buffer control routine;
FIGS. 12 (a) and 12(b) shows a flow charts of RECEIVED DATA processing;
FIG. 13 is a flow chart of PAGE EJECT processing;
FIG. 14 is a flow chart of FORMAT CONTROL CODE processing;
FIG. 15 is a flow chart of RECEIPT INTERRUPTION processing;
FIG. 16 is a flow chart of JEND signal interruption;
FIG. 17 is a flow chart of RECOVER signal interruption;
FIG. 18 is a flow chart of RECOVER processing;
FIG. 19 is a flow chart of the main routine to be executed by the second
information processor;
FIG. 20 is a flow chart of INTERMEDIATE CODE processing;
FIG. 21 is a flow chart of TROUBLE processing;
FIG. 22 is a flow chart of RECOVERY CHECK processing;
FIG. 23 is a flow chart of PRINT START processing;
FIG. 24 is a flow chart of an interruption routine by the print engine;
FIG. 25 is a flow chart of the main routine to be executed by the interface
controller;
FIG. 26 is a flow chart of BMC interruption;
FIG. 27 is a flow chart of SYSTEM TIMER interruption;
FIG. 28 is a block diagram of the bit map controller according to the
second preferred embodiment of the present invention;
FIGS. 29 (a) and 29 (b) show structures of JOB memory and MCB;
respectively,
FIG. 30 is a flow chart of the main routine to be executed by the first
information processor in the second preferred embodiment;
FIGS. 31 (a), 31 (b)-I and 31 (b)-II show a flow chart of RECEIVED DATA
processing;
FIG. 32 is a flow chart of PAGE EJECT processing;
FIG. 33 is a flow chart of FORMAT CONTROL CODE processing;
FIG. 34 is a block diagram of RECEIPT interruption;
FIGS. 35 (a) and 35 (b) show a flow chart of the main routine to be
executed by the second information processor in the second preferred
embodiment of the present invention;
FIG. 36 is a flow chart of PRINT END processing according to the second
preferred embodiment;
FIGS. 37 (a) and 37 (b) show a flow chart of INTERMEDIATE CODE processing
according to the second preferred embodiment;
FIG. 38 is a flow chart of BM-RAM CLEAR processing according to the second
preferred embodiment;
FIG. 39 is a flow char of PRINT START processing according to the second
preferred embodiment;
FIG. 40 is a flow chart of CLREQ 1 interruption according to the second
preferred embodiment;
FIG. 41 is flow chart of MCB STACK WRITE processing according to the second
preferred embodiment;
FIG. 42 is a flow chart of TROUBLE processing according to the second
preferred embodiment;
FIG. 43 is a flow chart of TROUBLE RECOVERY processing according to the
second preferred embodiment;
FIG. 44 is a flow chart of an interruption by the print engine according to
the second preferred embodiment; and
FIG. 45 is a flow chart of PAPER DISCHARGE processing according to the
second preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
First Preferred Embodiment
(a) Composition of Electro-photographic Printer
FIG. 1 shows an image forming system including a printer system 10
according to the present invention.
Data from an external data processor 1 such as a host computer are once
stored into an external file buffer 2 in order to improve throughput of
the external data processor 1 and, thereafter, are outputted from the file
buffer 2 to the printer system 10.
The printer system 10 is comprised of a data processor 3 for controlling a
bit map memory (See FIG. 4), a print engine 4 including a laser means and
an electro-photographic print means and accessory apparatuses such as an
external paper supply unit 5, a sorter 6 and the like.
FIG. 2 is a perspective view of the printer system 10.
The print engine 4 installs the bit map data processor 3 therein and the
external paper supply unit 5 and the sorter 6 are assembled to the print
engine 4. On a front edge portion of the upper surface of the body of the
print engine 4, there is provided an operation panel 44 having display
means for displaying various indications regarding the printer system and
a key means for inputting data and/or commands.
FIG. 3 shows a plan view of the operation panel 44. On the operation panel
44, entry keys 901 to 903 and indicators 910 to 918 are arranged. The key
901 is a PAUSE key for stopping a printing operation temporarily. The key
902 is a TEST key for performing a test printing operation. The key 903 is
a SHIFT key and becomes a CANCEL key for stopping a printing operation
when it is pushed down together with the TEST key 902. The reason why
CANCEL function becomes effective only when both of keys 902 and 903 are
pushed down at the same time is to avoid an undesirable cancel by a
careless operation.
FIG. 4 is a block diagram of the printer system 10.
The bit map data processor 3 is comprised of a bit map controller (BMC) 30,
a bit map random access memory (BM-RAM) 32, a bit map writer (BMW) 31 for
imaging bit images on BM-RAM 32 and a font memory means 33. Communication
between the bit map data processor 3 and the print engine 4 is done
through a bus means B3 for control data such as a number of prints,
accessory control signal and the like and a bus means B4 for image data.
The print engine 4 is essentially comprised of an interface controller 40,
an electro-photographic process controller 41 and a print head controller
42. The interface controller (IFC) 40 performs processing of control data
from the bit map controller 30, control of the operation panel 44 and
timing control of the print engine 4 through an internal bus B5. The
electro-photographic process controller 41 controls an
electro-photographic processor 45 according to data sent from the
interface controller 40 through the internal bus B5. The print head
controller (PHC) 42 controls a semiconductor laser (not shown ) and a
polygon mirror (not shown ) provided in a print head 43 according to
information sent from IFC 40 through the internal bus B5 in order to write
image data sent from BMW 31 through the internal bus B4. Also, the
external paper supply unit 5 and the sorter 6 are controlled, through the
internal bus B5, by IFC 40.
As is apparent from the above mentioned, the printer system 10 is a kind of
laser printer of bit map type. Print data (being usually represented by
codes) sent from the external data processor 1 are developed as dot images
on BM-RAM 32 of the bit map data processor 3 and, then, outputted to the
print engine 4. The print engine 4 writes dot images on a photoconductive
drum by controlling the laser means according to data sent from the bit
map data processor 3 and transfers written dot images on a blank paper
according to the electro-photographic process as is well known to those
skilled in the art.
Data sent from the external data processor 1 includes codes for control of
the print format and codes for setting respective modes of the print
engine 4 other than image data. The bit map data processor 3 analyzes
protocols of these codes other than character codes and outputs commands
for print format control, for supplying a blank paper to the print engine
4, for alteration of mode of the accessory and the like according to the
result of the protocol analysis. The print engine 4 performs various
controls such as control of the print head 43, timing control of a paper,
controls in synchronous with a paper feeding toward the sorter 6. These
controls are similar to those of an electro-photographic copy machine
except for control of the scanning system needed for the latter.
(b) Bit Map Controller
FIG. 5 shows a block diagram of the bit map controller 30 according to the
present invention.
In order to write dot images by the bit map writer 31, it is necessary to
calculate individual addresses in the font memory means and BM-RAM 32.
In the preferred embodiment of the present invention, there are provided a
first information processor 320 for analyzing data and a second
information processor 330 for print control and these two processors 320
and 330 are connected via a P-RAM 305 for memorizing intermediate codes as
shown in FIG. 5.
The first information processor 320 executes PACKET processing for data
stored temporarily in an R-buffer 304 in asynchronous with data entry. In
this packet processing, protocol analysis, pre-edition of image data,
transformation of them into intermediate codes as the result of the
pre-edition which are intended to make imaging into BM-RAM 32 easier and
storing intermediate codes into P-RAM 305 are performed successively. In
the pre-edition of image data, respective print positions of individual
image data are determined according to the result of the protocol
analysis. Therefore, every intermediate code includes a pattern code of
the image data and an address on BM-RAM 32 at which a dot image
corresponding to the intermediate code is to be formed.
As P-RAM 305, there is used a first-in first-out memory (hereinafter
referred to FIFO) in the present preferred embodiment. In FIFO 305,
transformed intermediate codes are sequentially written into an empty area
thereof while they are read out in the order according to which they have
been memorized therein. Thus, writing and reading of intermediate codes
are executed without aid of software. Accordingly, each information
processor 320 or 330 can operate irrespective of the other information
processor.
The R-buffer 304 for storing image data from the external data processor
temporarily is comprised of a ring buffer in which the last address is
followed by the top address as shown in FIG. 6(c). It is managed by three
pointers comprised of an R.sub.-- BOT pointer indicating an address
wherein the oldest data is stored, an R-TOP pointer indicating an address
wherein the most fresh data is stored and an R.sub.-- NOW pointer
indicating an address wherein the data in processing now is stored.
There is also provided an MCB (Map Control Block ) memory 310 for managing
data having been processed by the first information processor 320, as
shown in FIG. 5. The MCB memory 310 memorizes data in unit of page which
have been sent to FIFO 305, as shown in FIG. 6(a). The data in unit of
page, namely, MCB has a predetermined length and memorizes data in the
order of R.sub.-- TOP address indicating the top address of MCB (page data
) in R-buffer 304, R.sub.-- NEXT address indicating the top address of the
next page data in R-buffer 304, a parameter for setting a margin, a number
of prints, format control information, sorter information, a parameter
indicating the designated size of paper and so on, as shown in FIG. 6(b).
MCB memory is also comprised of a ring buffer similarly to R-buffer and is
managed by TASK.sub.-- BOT pointer indicating the top address of the
oldest MCB having been written therein, TASK.sub.-- TOP pointer indicating
the top address of the most fresh MCB therein.
On the contrary to the above, the second information processor 330 reads
stored intermediate codes from FIFO 305 to process them. It outputs
control commands for the print engine 4 corresponding to intermediate
codes to the print engine interface 307, outputs intermediate codes other
than control commands for the print engine to the bit map writer interface
306 and performs imaging of dot images into BM-RAM 32 and printing
operation.
Further, the second information processor 330 is connected to the first
information processor 320 through signal lines of RECOVER and JEND in
order to execute a recovery processing from a trouble in the print engine
4. It monitors the state of the print engine and sends signals through
these signal lines if necessary.
FIG. 7 shows a block diagram of the bit map writer 31.
Functions of the bit map writer 31 are generally classified into an imaging
function onto BM-RAM 32 and an outputting function for outputting data in
BM-RAM 32 to the print engine 4 upon printing.
The imaging function is further divided into an imaging function for
imaging lines and/or circles which is executed by a graphic image writer
(GIW) 316 and an imaging function for imaging characters which is executed
by a font image writer (FIW) 311. Both of the graphic and font image
writers 316 and 311 are operated according to packets sent from the bit
map controller 30 through a bit map controller (BMC) interface 317. The
graphic image writer 316 usually writes bit images on BM-RAM 32 according
to results obtained by analyzing parameters included in a packet, while
the font image writer 311 usually writes font images on BM-RAM 32 which
are read from the font memory 33 through a font memory interface 324
according to data in FIFO 305.
On the contrary, the output function for outputting data upon printing is
executed by a print head controller interface 315. Namely, when it
receives a PRINT START code sent from the bit map controller 30 through
the bit map controller interface 317, it outputs data in BM-RAM 32 to the
print head controller 42 in synchronous with synchronized signals sent
from a control circuit of the print head controller 42 through the bus B4.
FIG. 8 shows an example of hard-ware structure for the first and the second
information processors 320 and 330. Each of the information processors is
comprised of a CPU 321 (331), a system ROM 322 (332) memorizing programs
for CPU 321 (331), a system RAM 323 (333) to be used for a working memory
area and a timer 324 (334) for enabling CPU 321 (331) to control timing.
FIG. 9 shows an example of an image area.
Whole area A1 corresponding to a paper size is an area provided on BM-RAM
32. A margin area A2 is an area to be made remain blank upon printing and
an image area A3 is an area in which dot images are to be printed.
The print is started from a left upper corner of the image area A2 and is
proceeded in a printing direction A10. When a NEW LINE code is input, the
next print position is moved by a line width A12 set for a new line in a
new line direction A11. When a RETURN LINE code is input, the next print
position is moved to a return line position A13 on the left edge of the
image area A3.
(c) Bit Map Control
Hereinafter, operations of the printer system will be described according
to flow charts shown in FIGS. 10 to 27.
In the printer system according to the present invention, two main routines
are executed parallel by the first and second information processors 320
and 330, respectively.
<c-1>Routine by 1st information processor
FIGS. 12 to 17 are flow charts of routines to be executed by the first
information processor 320 of the bit map controller 30.
Referring to FIG. 10, when the power source is turned on at step #1, the
first information processor 320 is initialized internally at step #2 and,
then, R-buffer 304 for storing data received from the external data
processor 1 is cleared at step #3. Also, address pointers of each MCB are
reset at step #4 and, then control flags are initialized at step #5.
Concretely, LPWRITE flag for indicating "preediting stage" in a received
data processing routine, RECF flag indicating that RECOVER interruption is
requested from the second information processor 330 and LPSTART flag
indicating start of each page data are cleared, respectively. As stated
above, FIFO 305 is forcibly cleared upon switching on the power supply.
Then, at step #6, a font attribution is read from the font memory 33 in
preparation for transformation into intermediate codes in order to
determine a font format of characters to be printed.
After completion of these preparation operations, the process enters into a
main loop including steps from #7 to #14. In this main loop, analysis of
received data and transformation into intermediate codes are executed. At
first, data sent from the external data processor 1 are stored in R-buffer
304 by an interruption routine (See FIG. 15) for receiving data which is
started in asynchronous with the main loop by a REQUEST command from the
data processor interface 308.
In the RECEIPT INTERRUPTION routine of FIG. 15, each of received data is
reset is read out from the data processor interface 308 at step #191 and,
if there is an empty area in R-buffer 304 (YES at step #192), the read
data is written into at the address of R-buffer indicated by R.sub.-- TOP
pointer at step #193.
If FIFO 305 is not full at step #7, MCB buffer 310 is not full at step #8
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