JP2001277606A - Printing system, its control method, and computer readable storage medium with the control program stored therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely carry out double-sided printing without troubles by simple control in a printing system comprising a printer capable of executing double- sided printing in a through path method and a controller. SOLUTION: When double-sided printing is carried out, at a time point when image data of a set of even number pages of at least two pages which are to be printed to a first front face and a second rear face of the same paper are formed from printing data from a host apparatus, the controller notifies information on the printer, a paper feed position, a delivery position for printing the first face and the second face, etc., related to the even number pages to the printer (73), orders (75) to start printing and sequentially transmits the image data of the even number pages one page by one page to the printer to print the data. Immediately before the data of each one page are transmitted, it is informed from the printer whether the paper fed to print the data is a fresh unused paper or the paper whose first face is printed and which is fed again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus capable of performing double-sided printing, and a print control apparatus which creates image data from print data given from a host apparatus and transmits the image data to the printing apparatus to print on paper. The present invention relates to a printing system, a control method thereof, and a computer-readable storage medium storing the control program.

[0002]

2. Description of the Related Art Conventionally, image reading means for reading an image of a document and converting it into a signal of image data (raster data for each scanning line), memory means for holding the image data, and outputting the held image data There is a printing device that includes an output unit that performs printing and a printing unit that prints an image based on the image data output from the output unit on a sheet, and operates as a copying machine. Further, there is a printing system in which a controller is connected to the printing apparatus as a print control apparatus that creates image data from print data provided from an external higher-level apparatus, for example, a host computer, and causes the printing apparatus to print. In this system, print data of a document created by a higher-level device is sent to a controller, and the controller expands the print data into bitmap data as image data and stores it in an internal memory. By outputting to a printing device and printing it on paper, it can operate as a printer,
It can operate as both a copier and a printer in response to instructions from the operator. The controller has a large-capacity memory and can store a large number of pages of image data by compressing the bitmap data. Also, while the image of one page is being developed into a bitmap, the bitmap data of the page that has already been developed can be output to the printing apparatus as raster data for each scanning line and printed.

In addition, there is a printer capable of performing double-sided printing, in which printing is performed on both sides of a sheet by the above-described printing apparatus, and there are two types of printing. In either type, the paper transport path forms a loop with the main paper transport path from the paper feeding section for unused paper, such as a paper cassette, to the printing section through the printing section to the output tray outside the apparatus. A re-feeding conveyance path is provided for re-feeding the paper printed and discharged on the first surface on the front and back sides by the printing unit to the printing unit for printing on the second surface. Further, a reversing mechanism for reversing the direction of the front and back of the paper is provided in the middle of the re-feeding conveyance path.

[0004] The apparatus of the first type has an intermediate tray capable of stacking a plurality of sheets in the middle of a refeeding conveyance path in the apparatus. A plurality of unused sheets are sequentially fed to the printing unit from the set, and the first side of the front and back sides are collectively printed, and the sheets discharged from the printing unit are transferred from the main sheet feeding path to the feeding path for re-feeding. The sheet is conveyed and stacked on the intermediate tray, and thereafter, the sheets from the intermediate tray are sequentially re-fed to the printing unit to print the second surface, and are discharged to a discharge tray outside the apparatus. When performing double-sided printing of a document exceeding the number of stacked sheets in the intermediate tray, the operation of putting the document in the intermediate tray and then out the same for each number of stacked sheets is repeated (hereinafter, this is referred to as an intermediate tray method).

[0005] In the apparatus of the second system, when two-sided printing is performed on a plurality of sheets without using the intermediate tray, one unused sheet is newly fed from the sheet feeding section to the printing section. An operation of printing on the first side of the front and back sides of the sheet, and re-feeding one sheet printed on the first side to the printing unit from the re-feeding conveyance path by reversing the front and back sides; The operation of printing on the second surface on the front and back sides of the sheet is performed alternately in principle (hereinafter, this is referred to as a through-pass method).

In the above printing system, the controller and the printing apparatus are connected by a serial communication interface, and the controller is used as a master and the printing apparatus is used as a slave to communicate control commands predefined for print control. Is made. Here, in the printing system, the printing device is an intermediate tray type,
A control operation by communication of a control command between the controller and the printing apparatus when performing double-sided printing will be described with reference to FIG.

The controller develops the print data from the host computer into bitmap data as image data, and starts the communication of FIG. 6 when the development of bitmap data for an appropriate number of pages is completed.
At 01, the controller sends a status command to the printing device. This command is a command by which the controller inquires about the status of the printing apparatus.

On the other hand, the printing apparatus performs step 602
In response to a report (Report) command, the status of the paper such as out of paper, the presence or absence of an error, the operation, the door open,
Information on the status of the printing apparatus, such as during preparation and during printing, is returned.

Next, in step 603, the controller sends a ready page command to the printing apparatus. This command is a command for notifying the printing apparatus of information on prepared pages (pages that have been developed into bitmap data) that can be printed by the controller, and includes the number of prepared pages, the paper supply / discharge location (paper cassette, intermediate tray). , A paper ejection tray outside the apparatus, and color information (color, black and white). It should be noted that the page of the paper cassette where the paper supply location is the page printed on the first side of the front and back sides of the paper, and the page of the intermediate tray where the paper supply location is the page printed on the second side. Here, the ready page command is transmitted at least once before printing is started, and is separately transmitted each time attribute information such as a paper feeding / discharging place and a color mode is different. In this case, since the attribute of the paper supply / discharge location differs between the page printed on the first side and the page printed on the second side, in step 603, the ready page command is used to print on the first side of the prepared pages. Information about the number of pages to be printed, such as the number of pages, a paper feed location (paper cassette), a paper discharge location (intermediate tray), and a color mode, are sent to the printing apparatus.

On the other hand, when the printing apparatus receives the information sent from the controller and stores it in the memory, the printing apparatus proceeds to step 6
As indicated by “OK” in 04, the controller is notified that the information of the ready page command has been received. When the storage fails, a retransmission request is transmitted.

In step 605, the controller prints information about the prepared page to be printed on the second page (the paper feed location is an intermediate tray and the paper output location is a paper output tray outside the apparatus) by a ready page command. Send to device.

On the other hand, when the printing apparatus receives the information sent from the controller again and stores it in the memory, in step 606, it notifies the controller that the information of the ready page command has been received. When the storage fails, a retransmission request is transmitted.

In step 607, the controller sends a start command to the printing apparatus to start printing.

In step 608, the controller informs the controller whether or not the printer can start printing. When the controller notifies the controller that printing can be started, the controller transmits image data (raster data) to the printer. Make prints. Here, among the prepared pages, first, the image data of the pages to be printed on the first side of the number of pages notified to the printing apparatus by the ready page command in step 603 is sequentially transmitted one by one, and then, in step 605. , The image data of the page to be printed on the second side for which the attribute has been notified to the printing apparatus by the ready page command is sequentially transmitted one page at a time.

On the printing apparatus side, the image data is printed on the first side by sequentially feeding paper from the paper cassette to the printing section by the number of pages notified in step 603, and is discharged to the intermediate tray. When the process is completed, the sheets are sequentially fed again from the intermediate tray to the printing unit, printed on the second surface, and discharged to the discharge tray.

During printing, the controller periodically sends a status command to the printing apparatus (step 609) to check the state of the printing apparatus.

Then, the printing apparatus notifies the controller of the number of printed sheets in a print report of a report command (step 610), so that the controller knows whether the printing apparatus has finished printing and stopped. Ends its own processing.

As described above, the ready page command is transmitted separately every time attribute information such as a paper supply / discharge location and a color mode of a prepared page is different, and is used to develop bitmap data of a subsequent page. Although transmitted again as the process proceeds, the second and subsequent ready page commands may be transmitted during printing.

[0019]

However, in the above-described conventional printing system, there are the following two drawbacks when duplex printing is performed by a printing apparatus using an intermediate tray.

First, when performing double-sided printing of a larger number of sheets than the stackable number of sheets in the intermediate cassette, feeding from the sheet cassette and discharging to the intermediate tray, feeding from the intermediate tray and discharging to the outside of the apparatus are performed. Will be repeated,
At the time of the switching, the operation is interrupted, so that the productivity is lower than in the duplex printing by the through-pass method.

When printing on both sides of a plurality of sheets,
A plurality of sheets printed on the first side are put into the intermediate tray once and stacked, and then the stacked sheets are put out first and printed on the second side, so that the order of pages to be printed becomes irregular. The control regarding the page order of the controller that outputs the image data of each page to the printing apparatus becomes complicated.

On the other hand, if duplex printing is performed by a through-pass printing apparatus, duplex printing can be performed with higher productivity than an apparatus using an intermediate tray. However, there are the following problems.

In the printing apparatus of the through-pass system, feeding of a new sheet from the sheet cassette and re-feeding from the re-feeding conveyance path are alternately performed from the beginning to the printing unit, and the first side is re-formed from the beginning. If the printing of the second side is performed alternately, the order of the pages to be printed is simple, for example, 1, 2, 3, 4,... In ascending order, and the control on the page order on the controller side is also simple.

However, in practice, in many cases, feeding and refeeding of a new sheet are not performed alternately from the beginning.
It will be done from the middle. This minimizes the interval between the sheets to be fed and conveyed one by one in order to efficiently perform high-speed printing. However, if this is done, the loop of the main conveyance path and the re-feeding conveyance path is reduced. In many cases, the length is more than several times the length of the paper, so the first paper on which the first side is printed first after the printing is started is conveyed through the loop and can be fed again to the printing unit. Until then, several sheets from the beginning are supplied with new sheets continuously to the printing unit and the first side is printed on each sheet.

In this case, for example, suppose that the number of pages to be printed on the first side until the sheet can be re-supplied is set to four, and two-sided printing of a 16-page document is performed in ascending order.
The page order in which the controller sends the image data to the printing apparatus is 1-3-5-7-2-9-4-11-6-13-
8-15-10-12-14-16. Moreover, the page order differs depending on the number of pages to be printed.

Further, if the paper runs out during the double-sided printing of a plurality of papers, only the paper remaining in the refeeding conveyance path is re-fed after that.
The order of the new sheet feeding and the sheet re-feeding is different from the case where there is no paper shortage, and the page order in which the controller sends the image data to the printing apparatus also changes accordingly. In addition, in the printing apparatus, the order of the new sheet feeding and the sheet re-feeding may be different due to circumstances other than the sheet shortage.

Therefore, there is a problem that the control of the page order in which the controller sends the image data to the printing apparatus is complicated, and it is difficult to deal with troubles such as running out of paper.

Further, in a printing system including a printing apparatus and a controller of a through-pass system, when double-sided printing is controlled by communication of control commands similar to those of the intermediate tray system of FIG. Therefore, there has been a problem that printing on one side may fail in double-sided printing.

For example, in the controller, the development of the bitmap data for one page to be printed on the first side of the paper is completed, information about the page is notified to the printing apparatus by a ready page command, and then the one page is printed. When developing bitmap data for one page to be printed on the second side of the next sheet while transmitting the bitmap data to the printing apparatus for printing, in the through-pass method, new paper feeding and re-feeding are performed. Is performed continuously, and the conveyance of the paper is not stopped. Therefore, if it takes time to develop the bit map data for one page to be printed on the second surface, the paper on which the data is to be printed is printed. Part, and the second surface thereof is blank.

An object of the present invention is to provide a printing system comprising the above-described printing apparatus and a controller (print control apparatus), in which the printing apparatus performs duplex printing by a through-pass method. It is possible to easily control the order of pages for transmitting the image data described above, to cope with troubles such as running out of paper, to prevent failure of one-sided printing in the above-described two-sided printing, and to surely perform two-sided printing. To be able to do it.

[0031]

According to the present invention, in order to solve the above-mentioned problems, one unused sheet is newly fed to a printing unit and printed on the first side of the front and back sides of the sheet. Action
The operation of inverting one sheet printed on the first side, re-feeding it to the printing unit, and printing the second side of the sheet on the front and back sides of the sheet, in principle, is performed alternately. Image data is created from a printing device that performs printing, and print data of a document provided from a higher-level device, and the image data is sequentially stored in the printing device.
In a printing system including a printing control device that transmits to the printing device for each page and prints the printing device, a control method thereof, and a computer-readable storage medium storing a control program thereof, the printing device includes the printing control device. When performing double-sided printing by sequentially receiving image data for a plurality of pages one by one from the printer, immediately before the print control device transmits the image data for one page to the printing device, the image data for one page is Control is performed so as to notify the print control device whether the paper to be printed is supplied to the printing unit as the new paper supply or the re-feeding,
In the print control device, when image data for a plurality of pages is sequentially transmitted to the printing device one page at a time and two-sided printing is performed, the printing device transmits the new paper feed immediately before transmitting the image data for one page. When the notification is received, the first
One page of image data to be printed on the second side, and when receiving the re-feed notification, one page of image data to be printed on the second side is controlled to be transmitted to the printing apparatus. did.

Further, in the print control apparatus, when image data for a plurality of pages is created from print data given from a higher-level apparatus and the printing apparatus is to perform double-sided printing, the first and second sides of the same sheet are printed. When the image data for the even-numbered pages including at least one set of two pages to be printed on the surface is created, the information regarding the image data for the even-numbered pages includes at least the number of prints (the number of pages of the even-numbered pages / 2 × Information on the number of print copies), the paper feed location and paper discharge location for new paper feed for printing on the first side, and the paper feed location and paper discharge location for re-feeding for printing on the second side. After notifying the printing apparatus, the image data for the even-numbered pages is sequentially
It is assumed that control is performed so that printing is performed by transmitting the image data to the printing apparatus page by page. In the printing apparatus, when performing double-sided printing of image data sequentially transmitted one page at a time from the printing control apparatus, the image data is transmitted. Based on the information notified from the print control device before the transmission, the new sheet feeding and re-feeding are performed by the number of times corresponding to the number of prints, and the printing of the first side and the printing of the second side are performed. The printing is controlled so as to be performed by the number of times corresponding to the number of prints.

[0033]

Embodiments of the present invention will be described below with reference to the drawings.

[Explanation of the overall configuration of the printing system]
The configuration of the entire printing system of the present embodiment will be described with reference to FIG.

As shown in FIG. 1, the printing system according to the present embodiment includes a host computer 101 as a higher-level device,
Controller (print control device) 102 and printing device 1
It consists of 03. The printing device 103 functions as a color copying machine for copying a document placed on a platen in color, and also controls the computer 10 via the controller 102.
1 functions as a color printer used for print output. The printing apparatus 103 performs double-sided printing by the above-described through-pass method.

On the host computer 101, so-called DTP (Desk Top Publishing)
Various kinds of documents are created and edited by application software such as, and at the time of printing, the documents are printed by a printer driver in PDL (Page Discrete).
ion Language = Page Description Language, eg A
The print data is converted into print data such as PostScript (available from Dobe) and transmitted to the controller 102 through the connection cable 243.

The controller 102 analyzes print data such as PDL sent from the host computer 101,
It is developed into bitmap data as image data, and this is used as raster data for each scanning line. Then, the raster data signal is transmitted as an image data signal to the printing apparatus 103 via the connection cable 242, and the image data is printed on paper.

[Outline of Configuration and Operation of Printing Apparatus] Next, an outline of the hardware configuration and operation of the printing apparatus 103 will be described with reference to FIG.

First, as a configuration for a function as a copying machine, reference numeral 201 denotes a platen glass on which a document 202 from which an image is to be read is placed. The original 202 is illuminated by an illumination lamp 203 and its image is
An image is formed on a CCD sensor 208 as an image sensor by an optical system 207 via 4, 205, and 206.
Further, by driving the motor 209, the first mirror unit 210 including the mirror 204 and the illumination lamp 203 is moved in the direction of the arrow at the speed V, and the second mirror unit 211 including the mirrors 205 and 206 is moved in the direction of the arrow at the speed of 1 / 2V. , The entire surface of the document 202 is scanned,
The image is converted into an electric signal by the CCD sensor 208.

Reference numeral 212 denotes an image processing circuit which processes an electric signal input from the CCD sensor 208 as described later and outputs yellow (Y), magenta (M), and cyan (C).
Is converted into raster data as image data of three colors,
After temporarily storing it in the image memory 108 (see FIG. 3), the image data is further converted into raster data of four colors of yellow, magenta, cyan, and black (Bk), and each of the raster data signals is output as an image signal.

The four color image signals output from the image processing circuit unit 212 are sent to a laser driver (not shown).
Thereby, four semiconductor lasers (not shown) corresponding to the four colors are driven, and flicker in accordance with image signals.

Reference numeral 213 denotes a polygon mirror.
It receives four laser beams emitted from one semiconductor laser. The four laser beams are sequentially transmitted to mirrors 214, 215, 216 and 218, 219, 220, respectively.
222,223,224 and 226,227,22
8, the photosensitive drums 217, 221, 225, 229
Is scanned. This scanning forms an electrostatic latent image on each photosensitive drum.

On the other hand, 230, 231, 232, 233
Are developing units for supplying yellow, magenta, cyan, and black toners, respectively.
The respective color toner images corresponding to the electrostatic latent images are formed on 7, 221, 225, and 229. By transferring the toner images of the four colors (Y, M, C, and Bk) formed as described above onto a sheet, a full-color output image can be obtained.

The paper is fed from one of the paper cassettes 234 and 235 for feeding unused paper and the manual feed tray 236, is attracted onto the transfer belt 238 via the registration roller 237, and The developer is conveyed so as to pass through a printing unit in which the developing device is arranged. The toner of each color is developed in advance on the photosensitive drums 217, 221, 225, and 229 in synchronization with the paper feeding timing, and the toner of each color is sequentially transferred to the paper as the paper is transported. .

The paper on which the toner of each color has been transferred is separated from the transfer belt 238, transported by a transport belt 239, and the toner of each color is fixed by a fixing device 240.
Thereafter, the paper is discharged to a paper discharge tray 241 outside the apparatus.

On the other hand, in order to perform double-sided printing, a sheet cassette 2 for supplying unused sheets is provided in the printing apparatus 103.
34, 235 or from the manual feed tray 236, paper transport forming a loop with the main paper transport path passing through the above-described photosensitive drums, the developing unit, and the printing unit in which the fixing unit is disposed, and reaching the paper output tray 241. A feeding path for re-feeding the paper printed on the first surface on the front and back sides and discharged from the printing unit to the printing unit for printing on the second surface. . The transport path for re-feeding includes a paper vertical path 246 and a paper transport path 247. Along the transport path for re-feeding, near the fixing unit 240, a double-sided sheet for reversing the front and back of the sheet is provided. A reversing unit 245 is provided, and a re-feed unit 244 for adjusting the position of the sheet and re-feeding the sheet to the printing unit is provided near the entrance of the printing unit.

In the case of performing double-sided printing, the toner of each color is fixed on the first surface on the front and back sides by the fixing device 240 as described above, and the sheet on which the printing on the first surface is completed is vertically turned by the sheet deflector 248. The sheet is guided to the path 246, and is conveyed to the both-side reversing section 245 through the path. After a specified time after the leading edge of the sheet has passed between the rollers 249 and 250 of the double-sided reversing unit 245, the rollers 249 and 250 reversely rotate, so that the sheet is turned upside down.
And is conveyed to the re-feed unit 244. At this time, the upper surface of the sheet on the re-feed unit 244 is the surface on which the image of the first surface is printed. When the sheet is conveyed to the re-feeding section 244, the position of the sheet is adjusted, and then the sheet is re-supplied to the printing section. This is performed in the same manner as in the case of the front side, and the sheet is discharged onto the sheet discharge tray 241 after passing through the fixing device 240.

When performing double-sided printing on a plurality of sheets continuously, unused sheets are newly fed one by one from the sheet cassettes 234 and 235 or the manual feed tray 236 to the printing section one by one, and the sheets are fed as described above. After printing on the first side of the front and back sides, the paper is conveyed from the main paper conveyance path to the conveyance path for re-feeding, and when it reaches the re-feeding section 244, it is re-fed to the printing section from there, and The printing of the second side is performed. At this time, the sheet cassette 2 depends on the total number of sheets to be printed.
If the number of sheets to be newly fed remains from the sheets 34, 235, etc., re-feeding of one sheet via the re-feeding conveyance path and one new sheet from the sheet cassettes 234, 235, etc. The second side printing and the first side printing are alternately performed by feeding alternately, and the sheet on which the second side printing has been performed is output to the discharge tray 2.
Discharge to 41.

On the other hand, when the printing apparatus 103 operates as a printer for performing print output of the host computer 101, print data of a document is transmitted from the host computer 101 to the controller 102 via the cable 243, and the controller 102 The data is converted into bitmap data as image data, which is further converted into raster data for each scanning line, and the signal is transmitted to the printing apparatus 103 via the interface cable 242. The signal of the raster data is directly transmitted to a PWM circuit (not shown) that performs pulse width modulation for each pixel for density adjustment in the printing apparatus, and an output signal of the PWM circuit is transmitted to a laser driver (not shown). Is performed in the same manner as in the above-described copier operation.

The four photosensitive drums 217, 221,
Reference numerals 225 and 229 are arranged at regular intervals at a distance d, and the sheet is conveyed at a constant speed v by the transfer belt 238. Timing synchronization is performed at intervals of d / v, and four semiconductors 225 and 229 are provided. The laser is driven.

[Explanation of Image Signal Processing] Next, referring to FIG. 3, the operation of processing the image signal in the printing apparatus 103 will be described along with the configuration of the image processing circuit section 212 and the flow of the image signal.

In FIG. 3, an image signal corresponding to the image formed on the light receiving surface of the CCD sensor 208 is a digital signal for each of three color components of red (R), green (G), and blue (B). It is output to the masking circuit 112 as (R0, G0, B0).

The masking circuit 112 converts the input (R0, G0, B0) signal into a standard (R, G, B) signal by the operation of the following equation (1).

[0054] However, cij (i = 1, 2, 3, j = 1, 2, 3) is
This is a constant unique to the device in consideration of various characteristics such as the sensitivity characteristics of the CCD sensor 208 and the spectral characteristics of the illumination lamp 203. The (R, G, B) signal is output from the luminance / density conversion unit 104,
It is sent to the character / line drawing detection circuit 105.

The luminance / density conversion unit 104 is constituted by a look-up table of RAM or ROM, calculates the following equation (2), generates the M1, C1, and Y1 signals and outputs the signals to the output masking / UCR circuit unit 106. Output.

C1 = −K × log10 (R / 255) M1 = −K × log10 (G / 255) (2) Y1 = −K × log10 (B / 255) (K is a constant) Output masking / UCR circuit The unit 106 includes M1, C1,
The Y1 signal is converted to the toner colors Y, M,
The signal is converted into C and Bk signals, and the conversion is performed by the operation of the following equation (3).

[0057] Where aij (i = 1, 2, 3, 4, j = 1, 2, 3,
4) is a constant unique to the apparatus in consideration of various color characteristics of the toner, and further, Bk1 = min (C1, M1, Y1) (4).

As described above, based on the equations (2), (3) and (4), the R, G, and B read by the CCD sensor 208 are obtained.
The C1, M1, Y1, and Bk1 signals based on the signals are corrected to C, M, Y, and Bk signals based on the spectral distribution characteristics of the toner and output.

On the other hand, the character / line drawing detection circuit 105 determines whether each pixel in the original image is a part of a character or a line drawing based on the R, G, and B signals input from the masking circuit 112, and outputs a determination signal. TEXT is generated and output to the compression / expansion circuit 107.

The compression / expansion circuit 107 outputs the image signal (R,
G, B) and the data of the character / line drawing determination signal TEXT to reduce the amount of information, and then reduce the amount of information.
08, and expands the compressed data read from the image memory 108 into the original image signals (R, G, B) and the character / line drawing determination signal TEXT.

Note that the image processing circuit section 212 including the above components is provided by the CPU 30 that controls the entire printing apparatus 103.
1 and performs the above-described image processing under the control. The CPU 301 performs various types of information processing using the RAM 303 as a working area or the like according to a control program stored in the ROM 302, and
, An image processing circuit unit 212, a laser scanning system, a printing unit, a paper transport system, and the like. In addition, it communicates with the controller 102 via a communication interface (not shown).

On the other hand, in the controller 102, C
The PU 110 controls the whole according to a control program stored in the ROM 113. When the controller 102 causes the printing apparatus 103 to perform printing, the CPU 110 synchronizes with the printing timing of the printing apparatus 103 and sets the image memory (RA).
M) The raster data of the Y, M, C, and Bk signals corresponding to the spectral sensitivity characteristics of the toner as the image data stored in 109 is read and transmitted to the printing apparatus 103. It should be noted that the image data stored in the image memory 109 is output / masked by the image processing circuit 212 of the printing apparatus 103.
The data of the Y, M, C, and Bk signals transmitted from the UCR circuit unit 106 via the cable 242 or the CPU 1
Reference numeral 10 denotes data of Y, M, C, and Bk signals generated from print data of a document transmitted from the host computer 101.

Note that, in the configuration of FIG.
3 ROM 302 and the ROM 113 of the controller 102
Corresponds to an embodiment of a computer-readable storage medium storing a control program of the printing system according to the present invention.

Next, the operation of the printing system of this embodiment will be described. In this printing system, the printing device 103
Operation performed by the controller 10 as a single copier and the controller 10
There are both system operations, including 2. First, the operation of the copier alone will be described.

[Operation of Copying Machine Only] In the operation of the copying machine alone, the CCD sensor 208 for reading an image of a document is used.
Is processed by the masking circuit 112 and the luminance / density conversion unit 104 as described above, and the data is compressed by the compression / decompression circuit 107, after which the image memory 10
8 is written. The data of the character / line drawing determination signal TEXT as a result of the determination by the character / line drawing determination circuit 105 is also written in the memory 108 after being compressed by the compression / expansion circuit 107.

Next, according to the printing timing of the printing unit,
The image signal data and the character / line image determination signal TEXT data are read from the memory 108, decompressed by the compression / decompression circuit 107, and sent to the laser driver through a PWM circuit (not shown). The timing chart is shown in FIG.

In FIG. 4, image signal data read and processed by the CCD sensor 208 is denoted by 401.
Is written to the image memory 108 at the timing shown by.
The image data written in the memory 108 is read out at intervals of time d / v at timings indicated by 402, 403, 404, and 405, respectively, for yellow, magenta, cyan, and black, and output. Is done. Here, as described above, d is the interval between the four photosensitive drums 217, 221, 225, and 229 arranged at equal intervals, and V is the speed of the sheet conveyed by the transfer belt 238.

[System Operation Including Controller] Next, the system operation including the controller 102 will be described. The system operation including the controller 102 is roughly divided into a scan operation, a PDL expansion operation, and a printout operation.

First, the scanning operation will be described. This converts the image read by the CCD sensor 208 into
This is an operation of taking in the controller 102. The image signal output from the CCD sensor 208 is RGB data or Y,
The data is converted into M, C, and Bk data and stored in the memory 109.

Next, in the PDL developing operation, the CPU 110 of the controller 102 analyzes the PDL language print data sent from the host computer 101, develops the data into bitmap data of a full-color image, and writes the bitmap data on the image memory 109. It is. The bitmap data of the full-color image is adjusted according to the output characteristics of the printing apparatus 103.
The image data is developed as image data separated into four colors of yellow (Y), magenta (M), cyan (C), and black (Bk).

In the printout operation, the full-color four-color image data developed on the image memory 109 and the TEXT signal data as the result of character / line drawing determination are transferred to the four photosensitive drums 217, 221, 225, and 229.
Is read out one page at a time in synchronization with the print timing, and sent to a laser driver via a PWM circuit (not shown) to print out.

FIG. 5 shows a timing chart of the above system operation.

In FIG. 5, during the period indicated by 501, P
The DL expansion operation is performed, and at the same time, the determination signal TEXT is generated in a period indicated by 502, and the writing operation to each image memory 109 is performed at the same time. Image memory 109
The image data written on the top is yellow, magenta,
The cyan and black data are read out separately for one page of the same page at timings 503, 504, 505 and 506 at intervals of time d / v.

Here, by simultaneously performing the PDL expansion operation and the generation of the TEXT signal, the processing speed can be increased as compared with the case where these operations are sequentially performed. The control of the simultaneous processing of these operations is performed by the CPU 110.

[Duplex printing from host computer] Next, duplex printing from the host computer 101 will be described. After a document is created by an application program for document creation on the host computer 101, when an instruction for double-sided printing is input, PDL data for double-sided printing is generated as print data by the printer driver, and the PDL data is stored in the host computer 101. The controller 102 from the computer 101 via the cable 243
Transferred to

In the controller 102, the transferred PD
L data to the hard disk 11 in the controller 102
1 and the CPU 110 converts the PDL data into bitmap data as image data in the image memory 10.
Expand to 9. The bitmap data developed in the memory 109 is output as raster data for each scanning line via the interface cable 242 to the printing apparatus 103.
To start printing.

In the printing apparatus 103, first, the controller 1
02 is fed from the cassettes 234 and 235 or the manual feed tray 236 in accordance with an instruction on a paper feed location by a ready page command to be described later.
Adsorbed on the photosensitive drums 217, 221, 225, 2
The sheet is conveyed along 29, and the image is transferred to the first side of the front and back sides of the sheet. Therefore, at this time, the controller 102
First, it is necessary to send the image of the first surface to the printing apparatus 103.

The sheet on which the image on the first side has been transferred passes through the fixing device 240, the sheet vertical path 246 of the re-feeding conveyance path, the double-side reversing unit 245, and the sheet conveying path 247, and the re-feeding unit 24
4, the sheet is re-supplied to the printing section where the photosensitive drum is arranged, and printing is performed on the front and back second surfaces.
If the number of sheets to be newly fed remains from the paper cassettes 234, 235 and the like, and if the number of sheets to be newly fed remains from the paper cassettes 234, 235, etc. The second side printing and the first side printing are alternately performed by feeding the paper alternately.
Discharge to 1.

In this case, the paper cassettes 234 and 23
5 or the loop length of the main paper transport path from the manual feed tray 236 to the paper output tray 241 through the printing unit and the loop of the aforementioned re-feed transport path is several times or more the length of the paper, In order to perform high-speed printing efficiently at the time of double-sided printing of a plurality of sheets, sheets are sequentially fed at a minimum necessary interval.
It is assumed that four sheets, including the leading sheet, for example, are fed to the printing unit by the time the sheet can be re-fed and reach the printing section, and exist in the loop. In this case, if the total number of sheets to be printed is 5 or more, printing of the first side is performed four times continuously from the beginning, and then printing of the second side and printing of the first side are alternately performed. And the last printing is 4
It will be performed consecutively.

For this reason, the controller 102 sends the image data of each page to the printing apparatus 103, for example, when the image data of the document of one copy of 16 pages is sent to the printing apparatus 103 in an ascending order. 9-4-11-6-13-8-1
It is necessary to send to the printing apparatus 103 in the page order of 5-10-12-14-16.

This page order control is performed by the controller 102.
In order for the CPU 110 of the printer 103 to easily perform the re-feeding signal, the CPU 301 of the printing apparatus 103 transmits a sheet re-feeding signal indicated by reference numeral 81 in FIG. This re-feed signal is sent by the controller 102 to 1
The image data is transmitted at a timing immediately before the image data for the page is transmitted to the printing apparatus 103. Each time one sheet of paper is fed to the printing unit in the printing apparatus 103, this paper feeding is performed in the re-feeding conveyance path. The controller 102 determines whether re-feeding from the paper re-feeding unit 244 or new feeding of unused paper from the paper cassettes 234 and 235 or the manual tray 236 is performed.
Is a signal to be notified. The refeed signal 81 indicates refeeding when ON (high level) and new feeding when OFF (low level).

Here, in the case of re-feeding, the second side is printed on the sheet, and in the case of new feeding, the first side is printed on the sheet. Therefore, the CPU 110 of the controller 102 immediately before transmitting the image data of each page to the printing apparatus, if the refeed signal 81 is turned on, the page to be printed on the second side, that is, the page of the even number in the page order. It can be seen that the image data of the page to be printed on the first side, that is, the page of the odd numbered page should be sent if the refeed signal 81 is off. For example, depending on whether the printing page order is ascending or descending order, odd-numbered pages are image data in ascending or descending order with respective odd numbers, and even-numbered pages are ascending or descending order in respective even numbers. The order of the pages for transmitting the image data can be easily controlled.

Further, even if the order or number of new paper feeding and re-feeding is changed due to troubles such as running out of paper during the duplex printing of a plurality of documents, the CPU 110
The image data of the page to be printed on the first side or the page to be printed on the second side may be transmitted in ascending or descending order of the page numbers in response to ON or OFF of the refeed signal 81. It can be performed without any trouble in response to a trouble.

Note that the refeed signal 81 is transmitted to the printing apparatus 103.
, Is generated by the CPU 301 which controls so as to selectively perform new sheet feeding or sheet re-feeding. The generation is performed according to a control program stored in the ROM 302.

[Control by Communication Between Controller and Printing Apparatus During Duplex Printing] Next, a control operation by communication of a control command between the controller 102 and the printing apparatus 103 when performing duplex printing will be described with reference to FIG. I do. The meaning of each command shown in FIG. 7 is the same as that in FIG. 6 of the conventional example described above. The controller 10
Communication of control commands between the printer 2 and the printing apparatus 103 is performed under the control of the CPUs 110 and 301 according to the control programs stored in the respective ROMs 113 and 302.

When the CPU 110 of the controller 102 receives PDL data for double-sided printing from the host computer 101, it expands it as bitmap data in the frame buffer memory 109.

Then, the CPU 11 of the controller 102
0, the status command is sent to the printing apparatus 103 in step 71 of FIG.
An inquiry about the status of 3 is made.

On the other hand, the CPU 301 of the printing apparatus 103
Returns to the controller 102 the information on the state of the paper such as out of paper or the like, the presence or absence of an error, and the state of the apparatus such as whether the apparatus is ready or ready for printing in step 72 by a report command.

When the printing apparatus 103 notifies that printing is possible, the controller 102
The PU 110 is a bit of image data for an even page composed of at least one set of two pages to be printed on the first and second sides of the same sheet (two pages of an odd number and an even number continuous with page numbers). In step 73 at the time when the map data has been created and ready, a ready page command is transmitted to the printing apparatus 103.

The ready page command is a command for notifying the printing apparatus of information on image data of printable and prepared even pages for which the above-described bitmap data has been created. That is, the number of pages of the even-numbered pages / 2 × the number of print copies, a paper supply location for a new paper supply for printing on the first side (paper cassettes 234, 235 or manual feed tray 236).
And a paper discharge place (re-feeding conveyance path), a paper supply place (re-feed section 244) and a paper discharge place (paper discharge tray 241) for re-feeding for printing on the second side, and a first This is to notify information such as the color mode of the surface and the second surface.

Next, the printing apparatus 103 is connected to the controller 10.
When the information of the ready page command sent from 2 is received and stored in the memory, the controller 102 is notified in step 74 that the information of the ready page command has been received, as indicated by "OK". When the storage fails, a retransmission request is transmitted.

Here, the CPU 301 of the printing apparatus 103
After receiving the information of the ready page command, thereafter, the information on the printing of the first side and the information on the printing of the second side are separately managed. In particular, the number of times of printing on the first side (= the number of new paper feeds) and the number of times of printing on the second side (=
By separately managing the information on the number of refeeds based on the information on the number of prints, double-sided printing of the number of prints can be performed without error.

As described above, the ready page command is information on an even-numbered page including at least one set of two pages to be printed on the first and second sides of the same sheet in the prepared page of image data. The information on the page to be printed on the first side or the information on the page to be printed on the second side is, for each of the two pages to be printed on the same sheet, the information on the two pages to be printed on the previous sheet. When the information is different, the information is notified again by a new ready page command each time. However, 2
The second and subsequent ready page commands may be transmitted during printing.

Next, the CPU 110 of the controller 102
Sends a start command to the printing apparatus 103 to start printing in step 75 when there is a notification that the information of the ready page command has been received from the printing apparatus 103.

On the other hand, in step 76, the CPU 301 of the printing apparatus 103 notifies the controller 102 whether printing can be started.

When the user is notified that printing can be started as indicated by "OK" in the figure, the controller 102
The PU 110 sequentially transmits the prepared four-color image data (raster data) for the even-numbered pages to the printing apparatus 103 one page at a time as shown in FIG.

That is, the CPU 1 of the controller 102
Reference numeral 10 denotes a page enable signal (cyan CPE 82, magenta MPE) for each color sent from the printing apparatus 103.
83, yellow YPE 84, black KPE 85), and sequentially transmits one page of image data of each color.

When the re-feeding signal 81 is turned on immediately before the page enable signal 82 of the first station (cyan in this case), the controller 1
The CPU 110 of 02 transmits the image data of the page to be printed on the second side, and transmits the image data of the page to be printed on the first side when the refeed signal 81 is turned off.

Printing is performed by the printing apparatus 103 by transmitting such image data. During the printing, the CPU 110 of the controller 102 periodically sends a status command to the printing apparatus 103 as shown in step 77 in FIG.
To check the status of the printing apparatus 103.

The number of printed sheets in the print report of the report command from the printing apparatus 103 is determined by the controller 1.
02 is notified (step 78), the CPU 110 of the controller 102 knows whether or not the printing apparatus 103 has finished printing and has stopped, and ends its processing when printing is finished.

In the double-sided printing control by the communication as described above, the CPU 301 of the printing apparatus 103 sets a new one from the paper cassettes 234 and 235 or the manual feed tray 236 based on the information of the ready page command notified from the controller 102. Feeding and refeeding from the refeeding section 244 of the feeding path for refeeding are performed, and the controller 1
Double-sided printing of image data transmitted one page at a time from 02 is performed.

At this time, the number of new sheet feedings (=
The number of times of printing on the first side) and the number of times of re-feeding (= the number of times of printing on the second side) are separately managed based on the information of the number of prints notified by the ready page command, and new feeding and re-feeding are performed. Feeding is performed by the number of times corresponding to the number of prints,
By performing the printing of the first side and the printing of the second side by the number of times corresponding to the number of prints, the double-side printing of the number of prints can be performed without fail.

Here, in this embodiment, the controller 1
When the CPU 110 of No. 02 finishes preparing bitmap data of image data for even-numbered pages including at least one set of two pages to be printed on the first and second sides of the same sheet, the ready page Since the command is transmitted to the printing apparatus 103 to notify the information about the prepared even-numbered page and to perform the printing, it takes time to develop the bitmap data of the subsequent page while printing as described above. Failure of single-sided printing in double-sided printing can be prevented beforehand, and double-sided printing can be reliably performed.

Also, as described above, the CPU 1 of the controller 102 receives the re-feed signal 81 from the printing apparatus 103.
The control unit 10 can easily control the order of pages for transmitting image data, and can cope with troubles such as running out of paper.

In the above, the controller 1 determines whether re-feeding or new feeding is to be performed according to the re-feeding signal 81 from the printing apparatus 103.
02, it may be notified by communication of a control command between the printing apparatus 103 and the controller 102. In this case, for example, the CPU 301 of the printing apparatus 103 responds to the status command of step 77 in FIG.
Informs the controller 102 of re-feeding or new feeding. The notification may be a notification of a paper feed place.

[0106]

As is apparent from the above description, according to the present invention, a printing apparatus capable of performing double-sided printing by a through-pass method, and image data created from print data given from a host apparatus, In a printing system including a print control device for transmitting data to a sheet and printing the data on a sheet, it is possible to easily control the order of pages in which image data is sequentially transmitted to the printing device one page at a time by the print control device during duplex printing. Troubles such as running out of paper during printing can be dealt with. In addition, it is possible to prevent time-consuming creation of image data of a subsequent page while performing printing of one page of image data in double-sided printing, thereby preventing one-sided printing from failing. Can be performed. An excellent effect that double-sided printing can be performed with high productivity by the through-pass method is obtained.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an entire printing system according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating a hardware configuration of a printing apparatus in the printing system.

FIG. 3 is a block diagram illustrating a configuration of an image processing circuit unit and the like of the printing apparatus and image processing thereof.

FIG. 4 is a timing chart showing an output timing of an image data signal from the image processing circuit unit.

FIG. 5 is a timing chart illustrating timings of PDL development, TEXT signal generation, and image data output in a controller in the printing system of the present embodiment.

FIG. 6 is an explanatory diagram showing communication of control commands during double-sided printing between a conventional intermediate tray type printing apparatus and a controller.

FIG. 7 is an explanatory diagram showing communication of control commands during double-sided printing between the printing apparatus and the controller in the printing system of the embodiment.

FIG. 8 is a timing chart of a refeed signal of the printing apparatus and a page enable signal for controlling output timing of image data from a controller in the printing system.

[Explanation of symbols]

 101 Host Computer 102 Controller 103 Printer 110 CPU of Controller 113 ROM 212 Image Processing Circuit 217, 221, 225, 229 Photosensitive Drum 230, 231, 232, 233 Developing Unit 234, 235 Paper Cassette 236 Manual Feed Tray 240 Fixing Unit 241 Discharge Paper tray 244 Re-feed unit 245 Double-sided reversing unit 301 CPU of printing device 302 ROM

Claims (6)

[Claims] 1. An operation of newly feeding an unused sheet of paper to a printing unit and printing it on the first side of the front and back sides of the sheet, and transferring the one sheet printed on the first side to the A printing device for performing duplex printing by alternately performing, in principle, an operation of inverting the front and back, re-feeding the printing unit, and printing on the second surface of the front and back of the paper, and a document provided from a higher-level device. A print control device that creates image data from the print data of the above and sequentially transmits the image data to the printing device one page at a time and prints the image data. When two-sided printing is performed by sequentially receiving one page of image data for each page, the print control apparatus prints one page of image data immediately before transmitting the one page of image data to the printing apparatus. Feeding to the printing unit A control unit for controlling the print control device to notify the new paper feed or the re-feed, and the print control device sequentially transmits a plurality of pages of image data to the printing device by one page. In the case of transmitting each page every minute and performing double-sided printing, one page of image data to be printed on the first side when the notification of the new sheet feeding is received from the printing apparatus immediately before transmission of one page of image data. And a control unit for controlling to transmit one page of image data to be printed on the second side to the printing apparatus when the notification of the re-feeding is received. 2. The printing control apparatus according to claim 1, wherein the print control apparatus generates a plurality of pages of image data from print data supplied from a host apparatus and causes the printing apparatus to perform double-sided printing. When the image data for even-numbered pages including at least one set of two pages to be printed on the surface is created, information on the image data for even-numbered pages is
At least the number of prints (the number of pages of the even pages / 2
X number of copies), information on the paper feed location and paper discharge location for new paper feed for printing on the first side, and information on the paper feed location and paper discharge location for re-feeding for printing on the second side. Control means for transmitting the image data of the even-numbered pages to the printing apparatus one page at a time and causing the printing apparatus to perform printing. When performing double-sided printing of image data sequentially transmitted one page at a time from the device, the new sheet feeding and re-sheet feeding are performed based on the information notified from the printing control device before the image data is transmitted. 2. The apparatus according to claim 1, further comprising control means for controlling the number of times corresponding to the number of prints to be performed, and controlling the printing of the first side and the printing of the second side to be performed a number of times corresponding to the number of prints. The printing system as described. 3. An operation of newly feeding an unused sheet of paper to a printing unit and printing the first sheet on the front and back sides of the sheet, and transferring the one sheet printed on the first side to the sheet. A printing device for performing duplex printing by alternately performing, in principle, an operation of inverting the front and back, re-feeding the printing unit, and printing on the second surface of the front and back of the paper, and a document provided from a higher-level device. A print control device for creating image data from the print data of the above and transmitting the image data to the printing device one page at a time in order to print the image data. When performing two-sided printing by sequentially receiving image data for a plurality of pages one by one from the control device, immediately before the print control device transmits the image data for one page to the printing device, the image for one page is printed. Before paper on which data is printed The print control unit is controlled to notify the print control unit whether the feed to the printing unit is the new feed or the re-feed, and the print control unit sequentially sends image data for a plurality of pages to the printing device. When transmitting one page at a time and performing double-sided printing, when the notification of the new paper feed is received from the printing apparatus immediately before transmission of one page of image data, one page of the one page to be printed on the first side is received. A control method for a printing system, comprising: controlling to transmit image data and one page of image data to be printed on the second side to the printing apparatus when the notification of the re-feeding is received. 4. When the printing control device creates image data for a plurality of pages from print data provided from a higher-level device and causes the printing device to perform double-sided printing, the first and second surfaces of the same sheet are used. When the image data for the even-numbered pages including at least one set of two pages to be printed on the surface is created, the information regarding the image data for the even-numbered pages includes at least the number of prints (the number of pages of the even-numbered pages / 2 × Information on the number of print copies), the paper feed location and paper discharge location for new paper feed for printing on the first side, and the paper feed location and paper discharge location for re-feeding for printing on the second side. After notifying the printing device, the image data for the even pages is sequentially transmitted to the printing device one page at a time so that printing is performed. In the printing device, one page is sequentially transmitted from the print control device to the printing device. Each When performing double-sided printing of image data to be transmitted, based on the information notified from the print control device before transmission of the image data, the number of times of the new sheet feeding and sheet re-feeding corresponding to the number of printed sheets is performed. 4. The method according to claim 3, wherein the control is performed such that the printing of the first side and the printing of the second side are performed by the number of times corresponding to the number of prints. 5. An operation of newly feeding an unused sheet of paper to a printing unit and printing the sheet on the first side of the front and back sides of the sheet, and transferring the one sheet of paper printed on the first side to the sheet. A printing device for performing duplex printing by alternately performing, in principle, an operation of inverting the front and back, re-feeding the printing unit, and printing on the second surface of the front and back of the paper, and a document provided from a higher-level device. A print control device for generating image data from the print data and transmitting the image data to the printing device one page at a time in order to print the image data by a computer-readable storage medium. In the printing apparatus, when performing two-sided printing by sequentially receiving image data for a plurality of pages one by one from the printing control apparatus, the printing control apparatus transmits the image data for one page to the printing apparatus. Immediately before performing the control, the control unit notifies the print control device of whether the paper for printing the image data for one page is supplied to the printing unit is the new paper supply or the re-feeding. A control program, wherein, in the print control device, when the image data of a plurality of pages is sequentially transmitted to the printing device by one page and printed on both sides, the printing device transmits the new image data immediately before transmitting the image data of one page. One page of image data to be printed on the first side when receiving a notification of proper paper feeding, and one page of image data to be printed on the second side when receiving the notification of re-feeding A storage program storing at least one of a control program and a control program for controlling transmission to the printing apparatus. 6. The printing control apparatus according to claim 1, wherein when the printing apparatus creates image data for a plurality of pages from print data provided from a higher-level apparatus and causes the printing apparatus to perform double-sided printing, the first and second sides of the same sheet are printed. When the image data for the even-numbered pages including at least one set of two pages to be printed on the surface is created, the information regarding the image data for the even-numbered pages includes at least the number of prints (the number of pages of the even-numbered pages / 2 × Information on the number of print copies), the paper feed location and paper discharge location for new paper feed for printing on the first side, and the paper feed location and paper discharge location for re-feeding for printing on the second side. A control program for transmitting the image data of the even-numbered pages to the printing apparatus one by one sequentially after the notification to the printing apparatus, and controlling the printing apparatus to perform printing; When performing double-sided printing of image data transmitted one page at a time from the printer, the new paper feeding and re-feeding are performed based on the information notified from the printing control device before the transmission of the image data. At least one of a control program for controlling the printing of the first side and the printing of the second side to be performed by the number of times corresponding to the number of prints is stored by performing the number of times corresponding to the number of prints. 6. The storage medium according to claim 5, wherein: