JP2002264436A - Perfecting printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the occurrence frequency of bad print quality on the surface being printed later in perfecting print. SOLUTION: When an operator transmits print data of perfecting print from a host apparatus to a printer, a data receiving means on the printer side receives that data and passes it to a data analyzing/executing means. The data analyzing/executing means writes surface page data in a surface image memory and rear surface image data in a rear surface image memory and then delivers a print start command to a perfecting print control means. In response to the print start command, the perfecting print control means counts the number of ON dots in the surface image memory and the number of ON dots in the rear surface image memory, makes a decision that the surface having a smaller number of ON dots is printed first and controls the operation to print that surface first and the other surface next.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing system for a double-sided printing apparatus, and more particularly to a tandem type color printer.

[0002]

2. Description of the Related Art Conventionally, in a printer equipped with a double-sided printing apparatus, when performing double-sided printing, the printing order of the front side and the back side is fixed according to the paper surface direction (face up / face down) at the time of discharge. Was decided. For example, in the case of face-down discharge, the back surface (the surface with the larger page number) is printed first, the front surface (the surface with the smaller page number) is printed later, and then the paper is discharged.

Conventionally, manual double-sided printing has been realized by intervention of a manual process by a user. For example, when print data on the back side is sent from the host computer to the printer, the printer feeds paper from a paper cassette, prints the received print data, and discharges the paper with the back side printed on a paper output tray.

When the printing on the back side is completed, a message is displayed on the host computer for setting the paper in the paper discharge tray in the paper cassette with the print side up and designating the paper direction. When the user sets a sheet based on the instruction and clicks an OK button in response to the message from the host, the host sends print data of the front side to the printer. As with the back side, the printer feeds paper from the paper cassette, prints the received print data, and discharges the paper printed on both front and back sides to a paper discharge tray.

Conventionally, there is a printer in which a double-sided paper feeding unit can be incorporated in a printer body.

[0006]

In the above conventional example,
When performing double-sided printing, it is desirable that the back surface of the surface on which printing is performed be free of toner as much as possible. This is because when a large amount of toner is deposited on the surface on the back side of the surface on which printing is performed, poor printing quality such as poor fixing is likely to occur. In particular, when a color is expressed by mixing a plurality of color materials as in a color printer, the amount of the toner increases because the toner generally adheres two or three times.

In a printer equipped with a conventional double-sided printing apparatus, when performing double-sided printing, as described above,
Since the printing order of the front and back sides is fixed, for example, if the amount of toner on the side to be printed first is large, poor print quality is likely to occur when printing on the side to be printed later. There was a problem.

Furthermore, when fixing is performed during double-sided printing, when only one side is printed, heat is consumed for fixing the toner on one side. Next, when fixing toner adhering to the other side of the sheet on which one side is already fixed, the toner on the opposite side must be heated through the toner on the already fixed side, so that the toner layer Is preferred. The surface to be fixed later requires more heat.

In a printer in which a double-sided paper feeding unit can be incorporated in the printer main body, when the double-sided paper feeding unit is not mounted, the space is wasted.

[0010]

According to the first aspect of the present invention, in a double-sided printing apparatus for performing recording processing on the front and back surfaces of a recording material, the recording processing amounts on the front and back surfaces are compared by the recording processing amount discriminating means. Since the discrimination is performed first on the side with the larger recording processing amount, it is possible to suppress the occurrence of poor print quality during the recording processing on the side on which the recording processing is performed later. Achieved.

According to the fifth aspect of the present invention, the plurality of recording materials and the front / back pair data identification information corresponding to each of the plurality of recording materials are transmitted from the host device to the double-sided printing device. The printing device reads the front / back data identification information on the back surface by the reading means when performing the recording process in the order of the back surface and the front surface, and when performing the recording process on the front surface of the same recording material by the monitoring means, If the front-back pair data identification information does not match, the above-described problem is achieved by stopping the recording process on the front surface.

According to a fifth aspect of the present invention, the recording processing includes:
Although the processing is performed in the order of the back surface and the front surface, it is also possible to combine with the first aspect. In this case, for example, control is performed so that the surface with the larger recording processing amount is the surface on which the recording processing is performed first, and the recording process is performed in the order of the surface with the larger recording processing amount and the surface with the smaller recording processing amount.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 shows an example of a so-called tandem type color printer. In the figure, a printer device is connected to a host device such as a personal computer by a cable (not shown).

The printer is composed of an upper part A of the apparatus main body and a lower part B of the apparatus main body. An operation panel (not shown) is provided on the upper part A of the apparatus main body, and a discharge section for printing paper is formed on the upper surface thereof. ing. The internal configuration of the printer device includes an image forming unit 1, a conveyance unit 2 for double-sided printing, and a paper feeding unit 3. Here, the image forming unit 1
This is a configuration in which four image forming units 4 to 7 are juxtaposed,
In the drawing, magenta (M), cyan (C), yellow (Y), and black (K) are arranged in this order from right to left. Among them, magenta (M), cyan (C), and yellow (Y) image forming units 4 to 6 are:
In this configuration, color printing is performed by subtractive color mixing, and the black (K) image forming unit 7 is used for monochrome printing.

Here, each of the above-mentioned image forming units 4 to 7
Are composed of a drum set C1 and a toner set C2, respectively, and have the same configuration except for the color of the developer stored in the developing container. Therefore, the configuration will be described using the image forming unit 6 for yellow (Y) as an example. The drum set C1 houses the photosensitive drum 10, the charger 11a, the cleaner 11e, and the like, and the print head 11b is disposed above the drum set C1. Toner set C
2 stores a developing roll 11c and toner.

The peripheral surface of the photosensitive drum 10 is made of, for example, an organic photoconductive material. Near the peripheral surface of the photosensitive drum 10, a charger 11a, a print head 11b, a developing roll 11c, a transfer unit 11d, Cleaners 11e are sequentially arranged. The photoreceptor drum 10 rotates in the direction of the arrow, and first, the peripheral surface of the photoreceptor drum 10 is uniformly charged by applying a charge from the charger 11a. And the print head 11
b, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum 10 by optical writing based on the printing information from the developing roller 11.
A toner image is formed by the developing process of c. At this time, the toner image formed on the peripheral surface of the photosensitive drum 10 is
This is based on the yellow (Y) toner stored in the toner set C2. Thus, the toner image formed on the peripheral surface of the photosensitive drum 10 reaches the position of the transfer unit 11d as the photosensitive drum 10 rotates in the direction of the arrow, and the photosensitive drum 1
The image is transferred onto a sheet that moves just below 0 in the direction of the arrow. A transfer voltage is applied to the transfer device.

The drum set C1 and the toner set C2 constituting each of the image forming units 4 to 6 include:
Each is detachably attached to the apparatus main body. On the other hand, the paper is transported by the paper feed cassette 8, the standby roller pair 12, the transport belt 13, the drive roller 14, and the like which constitute the above-described paper feed unit 3. The paper conveyed out of the standby roller pair 8
To the transfer belt 11 at a timing coincident with the toner image, and reaches each transfer device 11d.
Then, the toner image is transferred in each transfer device 11d,
The sheet on which the toner image has been transferred moves on the conveyor belt 13 in the direction of the arrow as the conveyor belt 13 moves, and is subjected to heat fixing processing in the fixing unit 16.

Further, not only the yellow (Y) toner image but also the magenta (M) and cyan (C) toner images are transferred onto the upper surface of the sheet, and printing of the color according to the subtractive color mixture is performed. Is performed. Note that the above-described paper includes not only paper carried out of the paper feed cassette 8 but also paper supplied from the MPF tray 9. In this case, the paper is carried in by the paper feed roller 9 a, Print processing is performed.

The fixing unit 16 includes a heat roller 16a, a pressure roller 16b, and an oil application roller 16a.
While the sheet is conveyed by nipping between the heat roller 16a and the pressure roller 16b, for example, the toner images of plural colors transferred to the sheet are melted and thermally fixed to the sheet. The oil application roller 16c has a function of applying release oil to the peripheral surface of the heat roller 16a and removing toner remaining on the heat roller 16a. Note that the fixing unit 1
6 is the switching flap 2
1 is transported upward or leftward on the paper.

On the other hand, the double-sided printing transport unit 2 is configured to be detachable from the apparatus main body, and is a unit to be mounted when performing double-sided printing by the printer of the present embodiment.
A plurality of reverse transport roller pairs 20a to 20e are disposed inside. In the case of double-sided printing, the switching flap 21
The paper is once sent upward by, for example, when the rear end of the paper reaches the transport roller pair 22, the transport of the paper is stopped,
Further, the sheet is transported in the reverse direction. With this control, the paper is carried into the paper transport path of the transport unit 2 for duplex printing set at the position indicated by the dotted line, and the reverse transport roller pair 20a to 20a
20e feeds the paper in the reverse direction, and the standby roller pair 1
2, the toner image is sent to the transfer unit at the same timing as the toner image as described above, and the toner image is transferred to the back surface of the sheet.

Here, the printer of this embodiment is further provided with a suction roller 23 downstream of the standby roller pair 12. Further, a suction bias voltage is applied to the suction roller 23. FIG. 2 is a circuit block diagram of the printer device having the above configuration. In FIG. 2, a circuit block includes an interface controller (hereinafter, I / F).
Controller) 75, printer controller 7
6, a printer printing unit 77, a CPU 78, a ROM 79, an operation panel 81, and an EEPROM 82. I
The / F controller 75 converts the print data supplied from the host device into bitmap data and develops the bitmap data in the frame memory 80. The frame memory 80 stores storage areas (80M, 80C, 80Y, 8) for each of magenta (M), cyan (C), yellow (Y), and black (K).
0K) is set, and the data of the front surface and the back surface of each color is developed in the corresponding area.

The data developed in the frame memory 80 is output to the printer controller 76 and output to the printer printing unit 77 under the control of the CPU 78. At this time, the data of each color of magenta (M), cyan (C), yellow (Y), and black (K) is supplied to the corresponding print head 11b.

The system program of the present embodiment is stored in the ROM 79, and the CPU 78 performs processing according to the system program. FIG. 3 is a schematic configuration diagram of the first embodiment of the present invention using the printer device configured as described above. FIG. 4 shows the paper transport order of the printing paper in the method of the present embodiment. FIG. 5 is a flowchart of the double-sided printing control unit of this example. Hereinafter, the operation of each unit will be described mainly with reference to the flowchart of FIG. 5 and FIGS. 3 and 4. In the following description, the device numbers 31 to 44 represent the numbers in FIG. 3, the symbols a to d represent the symbols in FIG. 4, and S101 to S114 represent the steps in FIG. 5, respectively.

In FIG. 3, a data receiving section 32 receives data transmitted from a host and transfers the data to a data analyzing / executing section 33. The data analyzing / executing unit 33 analyzes the received data and, if the received data is drawing data, performs drawing on an image memory (frame memory 80). Drawing in the image memory is performed by using the image memory (for the front surface) 41.
And the image memory (for the back surface) 42. When the drawing of the front side and the back side is completed and printing is possible, the data analysis / execution unit 33 sets the double-sided printing control unit 34
Issue a print start instruction. The duplex printing control unit 34
It is activated by a print start instruction from the data analysis / execution unit 33. First, the double-sided printing control unit 34 turns on the image memory (for front side) 41 (the effective dot number F on which an image is recorded).
_CNT and the number of ON dots R_CNT of the image memory (for the back surface) 42 are counted (S101, S102) to determine the image forming processing amount for each recording surface.
It is determined that the surface with the smaller number of ON dots (data) is the surface to be printed first. In practice, the number of ON dots on each surface is counted in parallel with the above-described drawing process for the image memory. It can be carried out. Further, the transfer address of the image memory corresponding to the surface to be printed first is set to the image memory transfer address (for first printing) 43, and the transfer address of the image memory corresponding to the surface to be printed later is set to the image memory transfer address ( (For post-printing) 44 (S103, S104).

Next, the double-sided printing control unit 34
7 is instructed to feed paper, and paper feeding is started (a in FIG. 4, S10).
5). After the start of sheet feeding, a first-side printing instruction is issued to the image memory data transfer unit 35 in order to print the first side to be printed (S106). Image memory data transfer unit 35
When receiving the first printing side printing instruction, the printing is performed by referring to the image memory transfer address (for first printing) 43 (S10).
7). After the printing on the side to be printed first is completed, the duplex printing control unit 34 instructs the duplex printing device control unit 36 to invert the paper,
The paper is conveyed to the duplex printer (FIG. 4, b, S10).
8). After the sheet is conveyed (sheet reversal), a post-print side print instruction is issued to the image memory data transfer unit 35 in order to print the side to be printed later (S109). When receiving the post-print side print instruction, the image memory data transfer unit 35 refers to the image memory transfer address (for post-print) 44 and performs printing (S110). After the printing of the surface to be printed later is completed, if the previously printed surface is the back surface (YES in S111), the double-sided printing control unit 34 instructs the paper ejection instruction unit 38 to eject the paper and lays down the final recording surface of the paper. In this state, a face-down sheet discharge and discharge onto the stacker (T1) is performed (c in FIG. 4). On the other hand, if the previously printed surface is the front surface (NO in S111), the duplex printing control unit 34 instructs the duplex printing device control unit 36 to reverse the paper again, and conveys the paper to the duplex printing device (FIG. 4
B, S112). After the paper is conveyed (paper reversal), a paper discharge instruction is issued to the paper discharge instructing section 38, and the print section passes without printing anything, and performs face-down discharge (c in FIG. 4).

In the above-described first embodiment, one image memory (for the front side) and one image memory (for the back side) are prepared. However, as in a color printer,
In a configuration having an image memory for each color material, four image memories (for the front surface) and four image memories (for the back surface) may be prepared, and the number of ON dots on all four surfaces may be counted.

In the above embodiment, the method of counting the number of ON (valid) dot data developed in the image memory (frame memory) by the counter to identify the amount of image formation has been described. A method of calculating the image formation amount on each recording surface based on control command information such as a drawing command to be performed may be used.

As described above, in the first embodiment of the present invention, printing is performed later by setting the printing order in the sheet surface direction in double-sided printing from the one having the smaller print blackening rate (total toner amount). This has the effect of reducing the frequency of occurrence of print quality defects during surface printing. In addition, by using a two-sided printing device (paper reversing device) to match the paper surface direction at the time of paper discharge, there is an effect that the page order of the output document is not disturbed. <Second Embodiment> Next, a second embodiment of the present invention will be described.

FIG. 6 is a schematic configuration diagram of a second embodiment of the present invention using the printer device having the above-described configuration. FIG. 7 shows the paper transport order of the printing paper in the method of this example. FIG. 8 is a flowchart of the double-sided printing control unit of this example. Hereinafter, the operation of each unit will be described mainly with reference to the flowchart of FIG. 8 and FIGS. 6 and 7. In the following description, the device numbers 31 to 44 are the numbers in FIG. 6, the symbols a to d are the symbols in FIG.
Steps 101 to S111, S201, and S202 represent steps in FIG.

The data receiving section 32 receives the data transmitted from the host 31 and transfers the data to the data analyzing / executing section 33. The data analyzing / executing unit 33 analyzes the received data and, if the received data is drawing data, performs drawing on the image memory. Drawing in the image memory is performed for each of the image memory (for the front surface) 41 and the image memory (for the back surface) 42. When the drawing of the front and back surfaces is completed and printing is possible, the data analysis / execution unit 33
Issues a print start instruction to the duplex printing control unit 34.

The double-sided printing control unit 34 is activated by a print start instruction from the data analysis / execution unit 33. First, the double-sided printing control unit 34 counts the number of ON dots F_CNT of the image memory (for the front surface) 41 and the number of ON dots R_CNT of the image memory (for the back surface) 42 (S101, S1).
02), the side having the smaller number of ON dots is determined as the side to be printed first. Further, the transfer address of the image memory corresponding to the surface to be printed first is set to the image memory transfer address (for first printing) 43, and the transfer address of the image memory corresponding to the surface to be printed later is set to the image memory transfer address ( (For post-printing) 44.

Next, the duplex printing control unit 34
7 is instructed to feed paper, and starts feeding paper (a, S10 in FIG. 7).
5). After the sheet feeding is started, a first printing side printing instruction is issued to the image memory data transfer unit 35 in order to print the side to be printed first. When receiving the first print side printing instruction, the image memory data transfer unit 35 refers to the image memory transfer address (for first printing) 43 and performs printing. After the printing on the side to be printed first is completed, the double-sided printing control unit 34 instructs the double-sided printing device control unit 36 to reverse the sheet, and conveys the sheet to the double-sided printing device (b, S108 in FIG. 7). Paper transport (paper reversal)
After that, in order to print the side to be printed later, a post-print side print instruction is issued to the image memory data transfer unit 35. When receiving the post-print side print instruction, the image memory data transfer unit 35 refers to the image memory transfer address (for post-print) 44 and performs printing. After printing of the surface to be printed later is completed, if the previously printed surface is the back surface (YES in S111), the duplex printing control unit 34 issues a face-down discharge stacker switching instruction to the discharge destination switching unit 39, In addition, a paper discharge instruction is given to the paper discharge instructing section 38 to perform face-down paper discharge (c in FIG. 7).
S202). On the other hand, when the previously printed surface is the front surface (S1
11; no), the duplex printing control unit 34
9, a face-up discharge stacker switching instruction is issued, and a discharge instruction is issued to the discharge instruction section 38, and the face-up sheet is discharged and accumulated on the stacker (T2) with the final recording surface of the paper exposed. The paper is discharged (d in FIG. 7, S201).

The discharge destination switching unit 39 includes a duplex printing control unit 34.
, When the face down discharge stacker switching instruction is received, the paper discharge destination is switched to the face down discharge stacker. When a face-up discharge stacker switching instruction is received from the duplex printing control unit 34, the paper discharge destination is switched to the face-up discharge stacker.

In the above-described second embodiment, each of the image memory (for the front surface) and the image memory (for the back surface) is one.
Each surface is prepared, but in a configuration having an image memory for each color material, such as a color printer, four image memories (for the front surface) and four image memories (for the back surface) are prepared, and all four surfaces are turned on. The number of dots may be counted.

As described above, in the second embodiment of the present invention, printing is performed later by setting the printing order in the paper surface direction during double-sided printing in the order of the smaller print blackening rate (total toner amount). This has the effect of reducing the frequency of occurrence of print quality defects during surface printing. In addition, by using a two-sided printing device (paper reversing device) to match the paper surface direction at the time of paper discharge, there is an effect that the page order of the output document is not disturbed. <Third Embodiment> Next, a third embodiment of the present invention will be described.

In the printer of FIG. 9, the toner / drum Black 7, the toner / drum Yellow 6, the toner / drum Cyan 5, the toner / drum Magenda
4, paper discharge tray 46, transport belt 13, paper feed cassette 8
Is the same as the color printer described above. The description of the other components that are the same as those of the above-described color printer will be omitted.

Further, in the present printer, an image sensor 47 as a reading means is mounted on the side opposite to the printing surface of the paper in the middle of the paper traveling route from the paper supply cassette 8 to the transport belt 13. In this example, the description is made by using a color printer, but a monochrome printer may be used.

When manual duplex printing is performed by the present printer, print data on the back side is sent from the host to the printer. The print data on the back side includes, together with normal print data, sheet number data (front / back pair data identification information) corresponding to one of the items (1) and (2) described below. (1) The paper number is printed on the edge of the paper in a color hardly understood by a person, such as Yellow or Stealth Ink.
(2) A sheet number is printed with a number, a symbol, or the like on a portion serving as a binding margin for double-sided printing.

The printer feeds paper through the paper feed cassette 8, prints the received print data and paper number, and discharges the paper with the back side printed onto the paper discharge tray 46. When the printing on the back side is completed, a message is displayed on the host for setting the paper in the paper output tray 46 in the paper cassette 8 with the print side up and designating the paper direction.

When the paper is set according to the instruction and the "OK" button is clicked in response to the message from the host,
The host sends print data of the front side and the paper number printed on the back side of the paper on which the front side is printed to the printer. The printer feeds paper from the paper cassette 8 to print the received front side.

When the leading end of the fed sheet passes through the image sensor 47, the end of the sheet or the sheet number printed on the binding margin is read by the back side printing, and sent together with the print data on the front side. Paper number,
If they match, print the front side.

On the other hand, if they do not match, a message is displayed and printing is stopped. At this time, when the printing is restarted, the printer operation options include restarting printing from the current printing page, skipping the current printing page and restarting printing from the next page, and printing the specified page. There are options such as skipping and starting printing from a subsequent page, canceling all subsequent printing, and the like.

When the paper is removed by the paper feed jam, since there is no back surface corresponding to the front surface, printing on the front surface is skipped and printing is resumed from the next page. In the case of multi-feeding, processing such as returning the multi-fed sheets in the paper discharge tray to the paper cassette and restarting printing from the current page is performed.

In the above description, the manual double-sided printing method has been described, but an automatic method may be used. That is, a method is used in which printing is performed only on the back side and then printing is performed only on the front side. In such an automatic system, it is effective to print the confirmation sheet number invisibly as a measure for preventing double feed error or the like.

In the above description, a paper number is assumed as data to be printed invisibly.
It is also possible to add a host number, a print job number, and the like. By adding the host number and the print job number together with the sheet number, it becomes possible to perform appropriate double-sided printing control when a plurality of print data is received.

As described above, in the third embodiment,
In manual duplex printing, when double feeds or jams occur, compared to the conventional method where the correspondence between the front and back sides of double-sided printing has shifted, by checking the paper number on the back side when feeding paper, When the correspondence between the front side and the back side of the printing is misaligned, the printing is stopped and the operator is notified before the printing in the misaligned state, so that the front side / the back side of the double-sided printing corresponds. Printing can be performed. This also leads to eliminating waste of paper due to reprinting. <Fourth Embodiment> Next, a fourth embodiment of the present invention will be described.

In the above-described third embodiment, printing is stopped when the paper number of the back side read by the image sensor does not match the paper number of the print data of the received front side. When the sheet number of the back side does not match the sheet number of the back side, control is performed so that these sheet numbers are made to match.

FIG. 10 shows a flowchart of control for matching the sheet numbers. The data receiving unit that has received the back side data from the host (S301) sends this received data to the data analysis / execution unit, and in response to a print start instruction from the data analysis / execution unit, the duplex printing control unit performs printing on the back side. Is executed (S302), the printing of the sheet number described in the third embodiment is performed at the same time when the printing of the back side is performed. If printing on the back side is not completed (S30
(No at 3), and returns to S301 to receive the back data of the next page. On the other hand, when printing on the back side is completed (S3
03, Yes), a message is displayed to the host to set the paper in the paper discharge tray 46 in the paper cassette 8 with the print side up and the paper orientation specified.

When the operator sets the paper based on the instruction and clicks OK in response to the message from the host, the host prints the front side print data and the paper number printed on the back side of the front side paper to the printer. Sent. The data receiving unit receives one page of surface data (S
304), and feed the paper (S305). When the leading edge of the fed paper passes through the image sensor, read the paper number printed on the edge of the paper or the binding margin by the previous back side printing, and compare it with the paper number sent with the print data on the front side If the sheet number of the front side data is smaller than the sheet number of the back side data (that is, the sheet number of the fed sheet) (S306: YES), the sheet number of the received data is stored (S306). 31
1), the received data is discarded (S312), and the next 1
The surface data for the page is received (S313), and S3 is performed again.
At 06, the size of the sheet number of the front side data and the sheet number of the back side data is determined.

On the other hand, in S306, if it is determined that the sheet number of the front side data is equal to the sheet number of the back side data, the process proceeds to S307, and in response to a print start instruction from the data analysis / execution unit, the double-sided printing control unit The printing of the front side is executed (S307), and when the printing of the front side of this page is completed (No in S308), the process returns to S304 to receive the front side data of the next page. On the other hand, if there is no next page and the printing of the front surface data has been completed (YES in S308), the printing process ends.

If it is determined in S306 that the paper number of the front side data is larger than the paper number of the back side data, the paper number of the back side data is stored (S321).
The fed sheet is discharged (S322). In the above description, a paper number is assumed as data to be printed invisibly, but a host number, a print job number, and the like may be added. By adding the host number and the print job number together with the sheet number, it becomes possible to perform appropriate double-sided printing control when a plurality of print data is received.

As described above, in the fourth embodiment,
In manual duplex printing, when double feeds or jams occur, compared to the conventional method where the correspondence between the front and back sides of double-sided printing has shifted, by checking the paper number on the back side when feeding paper, If the correspondence between the front side and the back side of the print is misaligned, before printing is performed in this misaligned state, the printer automatically prints with the paper number matched without stopping printing. There is little operator intervention. In addition, by notifying the number of the paper that has not been printed after the printing is completed, it is easy to reprint the paper that has not been printed. <Fifth Embodiment> Next, a fifth embodiment of the present invention will be described. In the fifth embodiment, the control of the fourth embodiment is performed using a printer in which a storage device (such as a hard disk) for storing received data is mounted on the printer device of the third embodiment.

At the end of double-sided printing, S311 and S311 in FIG.
In 321, if there is a stored paper number, the print data of the stored paper number is read from the above storage device without notifying the operator, and the double-sided printing process is performed again.
In S311 and S321, the back side data of the stored sheet number is sequentially read for each page, and the back side data is printed. At this time, the sheet number described in the third embodiment is also printed.

When the printing on the back side is completed, a message is displayed on the panel of the printer in which the paper in the paper discharge tray 46 is set in the paper feed cassette 8 with the print side up and the direction of the paper is specified. When paper is set based on the instruction and the switch on the panel of the printer is pressed, the surface data of the stored paper number is sequentially read for each page in S311 and S321, and paper is fed from the paper feed cassette 8.

When the leading edge of the fed paper passes through the image sensor, the paper number printed at the edge of the paper or the binding margin is read in the back side printing, and compared with the paper number stored together with the print data on the front side. (S30
6) Then, control of the fourth embodiment is performed.

After the printing is completed, if there is a sheet number stored again in S311 and S321, the process of the back side printing is performed again. In this way, after printing,
The above-described processing is performed until there is no more paper number stored in S311 and S321.

As described above, in the fifth embodiment of the present invention, in manual two-sided printing, for a sheet on which both sides have not been correctly printed, the printer does not instruct the printing of the corresponding page and the printer automatically prints the page. Since printing is performed,
Printing processing can be performed efficiently. <Sixth Embodiment> Next, a sixth embodiment of the present invention will be described.

In this embodiment, in a printer capable of mounting a double-sided paper feed unit, an n-th
It relates to a system that can be replaced with any one of paper feeding, a stacker, a finisher, and the like (that is, a method of separately using a double-sided paper feeding unit).

FIG. 11 is a side view of the printer main body according to the present invention, and shows a state where the double-sided paper feeding unit 51 is attached. A description will be given of a paper transport route when performing double-sided printing. The paper in the paper feed unit 3 is fed upward and to the right, and is transported on the transfer transport belt 13 from right to left. The discharge switching guide (switch flap) 2 that passes through the fixing unit 16
1 to the upper left, and reaches the paper discharge roller pair 24.

In the case of single-sided printing, the paper is discharged as it is and stored in the upper part of the printer. In the case of double-sided printing, after the head portion of the sheet slightly comes out of the sheet discharge roller pair 24, the sheet discharge roller pair 24 rotates in the reverse direction, the sheet advances downward, and From left to right. When the paper reaches the right end of the reverse transport belt 52, the paper is fed upward, and is transported again on the transfer transport belt 13 from right to left. At this time, printing is performed on the back surface of the sheet. Thereafter, the sheet passes through the fixing unit 16, the sheet ejection switching guide 21, and the sheet ejection roller pair 24, and is ejected to the upper portion of the printer.

As described above, the double-sided paper feeding unit is incorporated in the printer main body, and has a structure that can be easily attached and detached. As is apparent from the above description, the double-sided paper feeding unit has two functions of receiving paper from the printer main body and supplying paper to the printer main body. In this example, attention is paid to this point, and another paper feeding / discharging unit can be mounted instead of the double-sided paper feeding unit. These examples are shown in FIG.

FIG. 12A shows an optional paper feed unit 53, which includes a paper feed roller 54 and a connector 56.
b, a paper feed motor (not shown), a paper size detection sensor, and an MPU for controlling these. In the figure, a sheet 25 is a sheet rear end guide 55.
Is supported at one end.

FIG. 12B shows a stacker unit 57 which is a sheet storage unit. Stacker unit 57
Has a paper leading end guide 58 and a connector 56c. Then, it is used as a spare for a paper discharge unit above the printer main body. FIG. 12C shows the finisher unit 5
9 is shown. A punch section 60, a connector 56d, a feed motor (not shown), a staple motor, various sensors, an MPU for controlling these sensors, and the like are provided.

When the stacker unit 57 and the finisher unit 59 are used, the sheet is carried in from the upper left of these. Therefore, the above-described paper discharge switching guide 21 is switched to guide the paper to the lower left. 13 to 16 show connection signals of the engine controller 61 and the double-sided paper feed controller 62 and the like.

FIG. 13 shows signals used when connecting the engine controller 61 and the double-sided paper feed controller 62. In the drawing, + 24V is a + 24V power supply supplied from the engine body to the duplex sheet feeding unit,
Is +5 supplied from the engine body to the duplex paper supply unit.
V power, GND is GND connecting the engine body and the double-sided paper feed unit (only one is shown in the figure, but a plurality may be used), and SCL is a serial data transfer clock signal output from the engine controller. To SD
A is a bidirectional serial data signal, * RESET is a signal for resetting the line of the double-sided paper feeding unit output by the engine controller, and SIG1: * SEN1 is a sensor signal provided near the entrance of the paper to the double-sided paper feeding unit. SIG2: * SEN2 is a sensor signal provided near the exit of the paper to the duplex paper feed unit (both the MPU of the duplex unit and the engine body MPU are used). use)
* CONNECT indicates a signal input to the engine controller. * CONNECT allows the engine controller to know that a duplex feeder unit (or any other unit) is connected.

The engine controller and the double-sided paper feed controller mainly exchange information by serial signals of SCL and SDA. The engine controller is a master, and the duplex paper feed controller is a slave. In the double-sided paper feeding unit, there are an MPU for exchanging information, a stepping motor for conveyance controlled by the MPU, a stepping motor for jogger for aligning the horizontal position of the paper, a sensor for detecting the entrance and discharge of the paper, and the like.

The information from the engine controller to the double-sided paper feed controller includes the above-mentioned paper size information for the jogger, the conveyance speed information, and the like. All of this information does not require the speed of information exchange. On the other hand, a signal SIG required for the speed of information exchange
1: * SEN1, SIG2: * SEN2 are separately prepared as single-line signals.

FIG. 14 shows connection signals between the optional sheet feeding unit and the engine controller. The optional paper feed unit includes a paper feed motor, a paper size detection sensor, and the like. The paper size information is the serial signal SCL, SD
A recognizes the engine controller.

In order to rotate the paper feed motor, SIG1:
* FEED is prepared as a single-wire signal. Unlike the duplex sheet feeding unit, when the optional sheet feeding unit is attached, SIG1 is an output signal from the engine controller. FIG. 15 shows a state in which a stacker unit is attached to the printer instead of the duplex sheet feeding unit. The stacker unit is a storage unit for sheets, and therefore does not include a motor, a sensor, an MPU, and the like.

There is only a * CONNECT signal and GND for the engine controller to know the existence of the stacker unit. When there is no stacker unit, the * CONNECT signal in the engine controller is at "H" level, but when the stacker unit is connected, it becomes "L" level. Although this method is not shown, the same applies to other units such as a double-sided paper feeding unit.

FIG. 16 shows a state in which a finisher unit is attached to the printer in place of the duplex sheet feeding unit. In the finisher unit, there are an MPU, a feed motor, a staple motor, a jogging motor, a punch clutch, and various sensors.

The information from the engine controller to the finisher unit includes the paper size, presence / absence of punch,
There are a punch position, staple presence, a staple position, and the like. Information from the finisher unit to the engine controller includes error information, job completion information, and the like. Unlike the double-sided paper feed unit, the single-line signal SIG1,
SIG2 is not used.

As described above, the signals between the engine controller and the controller of each unit are almost common in terms of hardware by not using a part or changing the meaning of each unit.
For this reason, it is possible to use the same connector and to use the same connector without providing a separate connector for each unit.

FIG. 17 shows a flowchart when the engine controller identifies which unit is connected. * The CONNECT signal is provided in all units, and becomes "L" when the units are connected. * If CONNECT is “H” (NO in S401), it is determined that nothing is connected to the option unit (S402). * When CONNECT is “L” (Yes in S401), the engine controller 61
Uses the SCL and SDA serial signals to determine the type of unit. An address is assigned to each slave device, and ACK is returned only when the address specified by the master is its own address.

In this example, the duplex sheet feeding unit is assigned to address 1 and the finisher unit is assigned to address 3. If the ACK response does not wait for a certain period of time, the engine controller determines that the unit is not connected and checks the response with another address.
In this way, it is possible to easily confirm which unit is connected. Specifically, writing or reading is performed as the device address “0” (address of the duplex paper feeding unit 51) (S403). If an ACK response is received within a predetermined time (Yes in S404), the duplex paper feeding unit 51 is written. Is determined to be connected (S40).
5) If there is no ACK response within a certain time (S404)
No), write or read as device address '1' (address of optional paper feed unit) (S
406), if there is an ACK response within a certain time (S40)
7 is YES), it is determined that the optional sheet feeding unit 53 is connected (S408), and ACK is received within a predetermined time.
If there is no response (NO in S407), write or read as device address '2' (address of finisher unit) (S409), and
If there is a response of K (Yes in S410), it is determined that the finisher unit 59 is connected (S41).
1) If there is no ACK response within a predetermined time (S410)
No), it is determined that the stacker unit 57, which is likely to remain, is connected (S412).

After determining which unit is connected, the engine controller exchanges information according to each unit. As described above, SCL, SDA
Is used, but it can be handled by changing the meaning of the information bits according to each unit. This is advantageous in terms of cost, control program development period, and the like, as compared with a case where control is performed by a different connector and a different protocol for each unit in terms of hardware.
Further, in this example, single-line signals SIG1 and SIG2 are prepared, and it is possible to cope with a signal having an urgent timing (in the case of a double-sided paper feeding unit, SEG1 =
* SEN1, SEG2 = * SEN2, SEG1 = * FEED in the case of the optional sheet feeding unit, and SEG1 and SEG2 in other units are not used). Also,
On the engine controller side, the input / output direction of the SEG1 can be switched by a bidirectional buffer (in the case of * SEN1, the input to the engine body, * F
In the case of EED, output from the engine body).

As described above, according to the sixth embodiment of the present invention, options can be selected in accordance with the needs of the user, so that space is not wasted.

[0078]

As described above, according to the present invention, the printing order in the paper surface direction in double-sided printing is set to be smaller in the print blackening ratio (total toner amount), so that printing can be performed later. This has the effect of reducing the frequency of occurrence of print quality defects during printing on the surface to be printed. In addition, by using a two-sided printing device (paper reversing device) to match the paper surface direction at the time of paper discharge, there is an effect that the page order of the output document is not disturbed.

Further, according to the present invention, the printing order in the paper surface direction at the time of double-sided printing is set from the smaller printing black ratio (total amount of toner), so that the printing quality at the time of printing the surface to be printed later is improved. This has the effect of reducing the frequency of occurrence of defects. In addition, by using a two-sided printing device (paper reversing device) to match the paper surface direction at the time of paper discharge, there is an effect that the page order of the output document is not disturbed.

Further, according to the present invention, when a double feed, a jam or the like occurs in manual double-sided printing, compared with the conventional method in which the correspondence between the front side and the back side of the double-sided printing is misaligned, By checking the paper number of the back side printed invisibly, if the correspondence between the front side and back side of the double-sided printing is misaligned, stop printing before printing in this misaligned state and ask the operator. By notifying, it becomes possible to perform printing in which the front side / back side of double-sided printing corresponds. This also leads to eliminating waste of paper due to reprinting.

Further, according to the present invention, when a double feed, a jam or the like occurs in manual double-sided printing, compared with the conventional method in which the correspondence between the front side and the back side of the double-sided printing is shifted, the paper feeding time is reduced. If the correspondence between the front and back sides of double-sided printing is incorrect by checking the paper number of the back side printed invisible, the printer will not stop printing before printing with this misaligned state. Since the printing is automatically performed on the side by matching the sheet number, the intervention of the operator can be reduced. In addition, by notifying the number of the paper that has not been printed after the printing is completed, it is easy to reprint the paper that has not been printed.

Further, according to the present invention, in manual two-sided printing, printing is automatically performed by a printer on a sheet on which both sides have not been correctly printed, without instructing the host to print a corresponding page. Processing can be performed efficiently. Further, according to the present invention, options can be selected in accordance with the needs of the user, so that waste of space can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view of a printer device according to an embodiment of the present invention.

FIG. 2 is a circuit block diagram in the printer device of FIG.

FIG. 3 is a schematic diagram illustrating a configuration of a printer according to the first embodiment.

FIG. 4 is a diagram illustrating a paper transport order of printing paper according to the first embodiment.

FIG. 5 is a diagram illustrating a flowchart of a double-sided printing control unit according to the first embodiment.

FIG. 6 is a schematic configuration diagram of a printer according to a second embodiment.

FIG. 7 is a diagram illustrating a sheet conveyance order of printing sheets according to a second embodiment.

FIG. 8 is a diagram illustrating a flowchart of a double-sided printing control unit according to the second embodiment.

FIG. 9 is a schematic view of a printer according to a third embodiment.

FIG. 10 is a flowchart showing a process for matching sheet numbers in the fourth and fifth embodiments.

FIG. 11 is a schematic diagram of a printer according to a sixth embodiment (when a duplex sheet feeding unit is attached).

12A is a diagram illustrating an optional sheet feeding unit according to the sixth embodiment, and FIG. 12B is a diagram illustrating a stacker unit according to the sixth embodiment;
(C) is a diagram showing a finisher unit in the sixth embodiment.

FIG. 13 is a diagram showing a connection between an engine controller and a double-sided paper feed controller.

FIG. 14 is a diagram showing a connection between an engine controller and an optional paper feed controller.

FIG. 15 is a diagram showing a connection between an engine controller and a stacker short bar.

FIG. 16 is a diagram showing a connection between an engine controller and a finisher controller.

FIG. 17 is a flowchart showing processing when the engine controller determines which unit is connected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image formation part 2 Double-sided printing conveyance unit 3 Paper supply part 4-7 Image formation unit 8 Paper supply cassette 9 Openable paper supply tray 9a Paper supply roller 10 Photoconductor drum 11a Charger 11b Print head 11c Developing roller 11d Transfer device 11e Cleaner 12 Standby roller pair 13 Conveyor belt 14 Drive roller 15 Paper feed roller 16 Fixing unit 16a Heat roller 16b Pressure contact roller 16c Oil application roller 20a-20e Reverse transport roller pair 21 Switching flap 22 Transport roller pair 23 Suction (feed) roller 24 Discharge Paper roller pair 25 paper 31 host 32 data receiving unit 33 data analyzing / executing unit 34 double-sided printing control unit 35 image memory data transfer unit 36 double-sided printing device control unit 37 paper feed instruction unit 38 discharge instruction unit 39 discharge destination switching unit 40 Printer engine 41 Image memo (For front side) 42 Image memory (for back side) 43 Image memory transfer address (for first printing) 44 Image memory transfer address (for after printing) 46 Output tray 47 Image sensor 51 Double-sided paper feed unit 52 Reverse transport belt 53 Optional Paper feed unit 54 Paper feed roller 55 Paper trailing edge guide 56a to 56d Connector 57 Stacker unit 58 Paper edge guide 59 Finisher unit 60 Punch unit 61 Engine controller 62 Double-sided paper feed controller 63 Optional paper feed controller 64 Stacker short bar 65 Finisher controller 75 Interface controller 76 Printer controller 77 Printer printing unit 78 CPU 79 ROM 80 Frame memory 80M, 80C, 80Y, 80K Storage area 81 Operation Panel 82 EEPROM

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) G06F 3/12 G06F 3/12 P (72) Inventor Yasushi Oguri 2-229 Sakuragaoka, Higashiyamato-shi, Tokyo Casio (72) Inventor Shizuo Tsuchiya 2-229 Sakuragaoka, Higashiyamato-shi, Tokyo Casio Computer Co., Ltd. Tokyo Office F-term (reference) 2C061 AQ06 AR01 AR03 AS02 HK18 HN15 2H027 DB01 ED19 ED22 EK03 FA13 2H028 BA06 BA12 BB00 2H072 AB07 5B021 AA01 FF03 LG07 NN20

Claims (9)

[Claims] 1. A double-sided printing apparatus comprising: a recording material reversing mechanism; and a recording mechanism for performing recording processing on each side of the recording material, and performing recording processing on both the front surface and the back surface of the recording material. Receiving means for receiving, from a higher-level device, recording information of a plurality of pages corresponding to the front side having a small page number and the back side having a large page number for recording on a recording surface; Recording processing amount identification means, data analysis / execution means for generating image data to be recorded on the recording material based on the received recording information, and storage processing of each recording surface upon recording processing of one recording material A double-sided printing apparatus comprising: a double-sided printing control unit that performs a printing process first based on print information of a page having a large storage processing amount in accordance with an amount identification result. 2. A double-sided printing apparatus according to claim 1, wherein said recording processing amount discriminating means compares and identifies the number of effective dots to be recorded on each recording surface. 3. The recording information includes recording information of a plurality of colors, and the recording processing amount identification means performs comparison and identification based on the recording processing amounts for all colors on each recording surface. 2. Double-sided printing device according to 1. 4. The face-down stacker, further comprising: a face-down stacker for discharging and accumulating a recording surface of the recording material that has been processed last in the recording processing unit in a prone state, and the recording surface that has been processed lastly. A face-up stacker that is discharged and accumulated in a state where the recording material is exposed to the front, and a discharge destination switching unit that discharges the recording material to one of the face-up stacker and the face-down stacker. 2. The two-sided printing apparatus according to claim 1, wherein the means selects a discharge destination stacker in accordance with designation of a recording order of the front and back surfaces of the recording material by the double-sided printing control means. 5. A double-sided printing apparatus for performing recording processing on both the front and back surfaces of a recording material, wherein front and back pair data identification information for identifying a pair of page data to be recorded on the front and back surfaces of the same recording material is provided. Receiving means for receiving recording information for a plurality of recording materials included in a page from a higher-level device; and when recording an image for the back surface on the recording material, recording the front / back pair data identification information on part of the recording material. Storage means, reading means for reading the front-back pair data identification information recorded on the back surface when recording on the front surface, and based on the front-back pair data identification information, whether there is an error in the supply order of the recording material. A double-sided printing apparatus comprising: monitoring means for monitoring; and recording stopping means for stopping recording on the front surface when the monitoring means identifies a mismatch between front and back data. 6. The double-sided printing apparatus according to claim 5, wherein the front / back pair data identification information is recorded on at least one side of the recording material with low visibility. 7. The double-sided printing apparatus according to claim 5, wherein the front / back pair data identification information is a number sequentially assigned to the recording material unit. 8. The double-sided printing device, when processing double-sided recording information for a plurality of recording materials, after completing all recording processes on the front surfaces of the plurality of recording materials, after the completion of all the recording processes, 6. A recording process is performed.
The double-sided printing device according to the above. 9. The double-sided printing apparatus according to claim 1, which is a tandem type color printer.