JPH05301397A - Perfecting printing device - Google Patents

Abstract

PURPOSE:To avoid curling of paper and deterioration of inside of a printer due to heat in a device by printing one face of a sheet in response to a perfecting print command, discharging it to a rear face convey passage, and feeding the paper in response to a paper feed command so as to print on the rear face. CONSTITUTION:A sheet PP is taken out from a paper feeder 20 under control of a mechanism controller 11 in response to a one face print command from a controller 10, conveyed by a convey passage 30, printed by a printing mechanism 3, and discharged. The sheet PP is taken out from the paper feeder 20 in response to a perfecting print command, conveyed by the convey passage 30, printed by the printing mechanism 3, discharged to a rear face convey passage 59, and is made to stand by. In response to a paper feed command from the rear face convey passage 59 from the controller 10, the sheet PP on standby is fed to the convey passage 30, printed on the rear face by the printing mechanism 3, and discharged.

Description

Detailed Description of the Invention

(Table of Contents) Industrial Application Field of the Prior Art (FIG. 6) Problem to be Solved by the Invention Means for Solving the Problem (FIG. 1) Action Example (a) Description of One Example (FIG. 2) To FIG. 5) (b) Description of another embodiment Effect of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prints one side of a sheet in accordance with a double-sided printing command, discharges the sheet to the back side conveying path, and feeds from the back side conveying path in response to a sheet feeding command from the back side conveying path. The present invention relates to a double-sided printing device that prints on the back side.

Printing devices such as copiers, printers, and facsimile devices are required to print on both sides of a sheet. Providing a printing mechanism for the front and back sides increases the size and cost of the printing device. Therefore, it is required to perform double-sided printing using one printing mechanism.

Therefore, a double-sided printing apparatus has been developed in which a sheet whose front surface has been printed by the printing mechanism is reversed and the back surface of the sheet is printed by the printing mechanism. In such a double-sided printing device, there is a device that causes a print sheet to stand by in the back side printing path and feeds the print sheet in the back side printing path with the following command to perform back side printing. If it is long, the sheet curls, and even if the sheet is printed on the back side and discharged, the curl remains, and a countermeasure against this is desired.

[0005]

2. Description of the Related Art FIG. 6 is an explanatory diagram of a conventional technique. In the double-sided printing device 1, as shown in FIG. 6A, the paper (sheet) PP taken out from the paper feeding unit 20 is sent to a printing mechanism (printing process unit) 3 including an electrophotographic mechanism, The toner image is transferred to the surface of the sheet, fixed and printed,
The paper is conveyed from the conveyance path 30 and discharged to the paper discharge unit 58.

At the exit of the conveyance path 30 of the printing mechanism 3, a back side printing conveyance path (double-sided path) 59 is connected, and the back side printing conveyance path 59 enters the sheet PP of the printing mechanism 3 at the time of double-sided printing. Transport to.

In this double-sided printing apparatus 1, the control unit 10 is
As a print start command, a single-sided print command for instructing discharge from the paper feed unit 20 to the paper discharge unit 58, and a paper feed unit 2
There are three types of commands: a double-sided printing command for instructing ejection to the double-sided path 59 by feeding from 0, and a back-side printing command for instructing ejection to the paper ejection unit 58 by feeding from the double-sided path 59.

Therefore, in the double-sided printing apparatus, when the double-sided printing command is received from the control unit 10, as shown in FIG.
The sheet is fed from the sheet feeding unit 20 and is printed by the printing mechanism 3 while being conveyed by the conveying path 30.
Then, the sheet is discharged to 9, and is made to stand by, and waits for the next back side printing command.

When the control unit 10 outputs the back side printing command, the sheet is fed from the double-sided path 59 and the conveyance path 3
While being conveyed by 0, back side printing is performed by the printing mechanism 3 and discharged to the paper discharge unit 58 to perform double-sided printing.

According to such a print start command, single-sided printing and double-sided printing can be performed in the same sequence in which the sheet feeding side and the sheet discharging side are designated, and the sheet is waiting in the double-sided pass 59 in the double-sided printing. In addition, a one-sided printing command can be issued, and emergency one-sided printing can be interrupted and executed, which is convenient.

[0011]

However, the prior art has the following problems. If you continue single-sided printing while the paper is waiting in the double-sided pass, the paper remains in the double-sided pass for a long time. to degrade.

If the back side print command is not issued due to a failure of the control unit or the like while the paper is on standby in the duplex path,
The paper remains in the double-sided pass for a long time, and the paper curls similarly and the print content deteriorates.

Therefore, it is an object of the present invention to provide a double-sided printing apparatus capable of detecting that a sheet remains in a double-sided path for a long time and dealing with the sheet.

[0014]

FIG. 1 shows the principle of the present invention. According to claim 1 of the present invention, the paper feed unit 2 is controlled by the mechanism control unit 11 in response to a single-sided printing command from the control unit 10.
The sheet PP is taken out from 0, and is conveyed by the conveyance path 30,
The printing mechanism 3 prints and ejects the sheet, and the sheet PP is taken out from the paper feed unit 20 in accordance with a double-sided printing command, conveyed by the conveyance path 30, printed by the printing mechanism 3, and ejected to the back side conveyance path 59. Then, the sheet PP on standby is fed to the conveyance path 30 in accordance with a paper feed command from the back side conveyance path 59 from the control unit 10, and the back side is printed by the printing mechanism 3. In the discharging double-sided printing apparatus, the mechanism control unit 11 outputs the sheet PP to the back surface conveyance path 59 from the control unit 10 within a specified time after discharging the sheet PP.
When a paper feed command from the printer is not received, an abnormality is reported to the control unit 10.

According to claim 2 of the present invention, in claim 1,
The mechanism control unit 11 is configured to discharge the sheet PP on the back side conveyance path 59 after reporting the abnormality. A third aspect of the present invention is characterized in that, in the second aspect, the control unit 10 transmits a double-sided printing command and reprint data to the mechanism control unit 11 after receiving the abnormality.

[0016]

According to the first aspect of the present invention, the mechanism control section 11 causes the sheet to be discharged to the back surface conveyance path 59 within a specified time.
When the back side print command does not arrive from the control unit 10, the sheet is kept waiting in the back side conveyance path 59 for a long time and may be curled. Therefore, this is notified to the control unit 10 as an abnormality.

In the second aspect of the present invention, the mechanism control section 11
When the back side print command does not arrive from the control unit 10 within the specified time, the sheet is curled and the print content is deteriorated. Therefore, in order to prevent the back side printing, the sheet is forcibly discharged. Then, the sheet is invalidated.

In the third aspect of the present invention, the control unit 10 that has received the abnormality notification issues the double-sided printing command and the reprint data to reprint because the sheet is discharged as invalid.

[0019]

【Example】

(a) Description of an Embodiment FIG. 2 is a block diagram of a printer according to an embodiment of the present invention, showing a printer.

As shown in FIG. 2, the double-sided printing apparatus 1 comprises a paper cassette 20, a printing mechanism 3 and a transport system 5, and the printing mechanism 3 comprises an electrophotographic unit for double-sided printing. It is configured to be possible.

The printing mechanism 3 includes a conveying path 30, a rotating photosensitive drum 31, and a pre-charger 3 for charging the photosensitive drum 31.
2, an optical system unit 33 for writing a light image on the photosensitive drum 31 to form a latent image, and the photosensitive drum 31.
Developing unit 34 for developing the latent image of the toner with toner, a standby roller 35 for waiting a sheet to be transferred, and a standby roller 3
5, a transfer / separator 36 that transfers and separates the toner image on the photosensitive drum 31 onto a sheet that is sent by 5, and a cleaner unit 37 that cleans the photosensitive drum 31 after transfer.
And a heat roller fixing device 38 for heat fixing the toner image on the paper.
Have and.

The paper transport system 5 includes a pick roller 50 for picking the paper in the paper cassette 2 and transport rollers 51a, 51b, 5 for carrying the picked paper to the standby roller 35.
1c, an impeller 54 that directs the trailing edge of the paper from the heat roller fixing device 38 to the back surface printing conveyance path 59, and the paper from the heat roller fixing device 38 after being conveyed in the discharge direction, and then the back surface printing conveyance path 59. And a switchback roller 55 for sending to.

Further, guide rollers 56a and 56b for guiding the discharge of the paper, a carry-out roller 57, a discharge tray 58 for storing the discharged paper, and a back side printing for
The paper from the switchback roller 55 conveys the paper 59
Conveyance path 5 for back side printing that is sent to the standby roller 35 by a and 59b
9 and.

The operation of the printer 1 is based on the paper cassette 2
From 0, pick with the pick roller 50, and transport roller 51
a, 51b, 51c to the standby roller 35, charged by the pre-charger 32, an optical system unit 33 writes an optical image, a latent image is formed, and a developing unit 34 forms a toner image. Synchronize with the toner image of.

The toner image of the photosensitive drum 31 is transferred onto the surface of the paper fed by the standby roller 35 by the transfer / separator 36, separated from the photosensitive drum 31, fixed by the heat roller fixing device 38, and switched back. It is sent in the direction of the roller 55, and is transported in the direction of the discharge tray 58 by the switchback roller 55.

When the trailing edge of the paper reaches the impeller 54,
When the switchback roller 55 stops the conveyance operation and stops the sheet, the rear end of the sheet is rotated in the counterclockwise direction of the impeller 54, so that the rear end of the sheet is directed to the rear surface printing conveyance path 59, and the switchback is performed. The roller 55 sends the paper to the back side printing conveyance path 59, and the paper is sent to the standby roller 35 by the conveyance rollers 59a and 59b of the back side printing conveyance path 59.

After that, as in the case of front surface printing, the standby roller 35
The toner image on the photosensitive drum 31 is transferred onto the surface of the paper by the transfer / separator 36, separated from the photosensitive drum 31, fixed by the heat roller fixing device 38, and sent toward the switchback roller 55. , Switchback roller 5
5, the sheet is conveyed in the direction of the discharge tray 58, and the discharge roller 57
Thus, the paper is discharged to the discharge tray 58, and double-sided printing is performed.

In the case of single-sided printing, only the front side is printed and the sheet is discharged to the discharge tray 58. Such a printing apparatus 1 is
Since the sheet cassette 2 is mounted from the front side, accommodated in the apparatus, and discharged to the upper discharge tray 58, space is not required on both sides, space can be saved, and the discharge path is used as a switchback. Therefore, the device can be downsized and double-sided printing can be performed.

FIG. 3 is a block diagram of an embodiment of the present invention. In FIG. 3, the same components as those shown in FIGS. 1 and 2 are represented by the same symbols, and 6 is a higher-level device,
A host computer, print data, and a print command issuing device, 10 is a control unit, which decodes an instruction from the higher-level device 6 and issues a print command or the like to the mechanism control unit 11. It is a mechanism control unit, and according to a print command (command) from the control unit 10, the print mechanisms 2, 3, 5
Controls the microprocessor (MPU)
12 and a counter (counter) 13.

FIG. 4 is a process flow chart of an embodiment of the present invention, showing a print process flow of the mechanism control section 11. The processor 12 of the mechanism control unit 11 waits for a print start command from the control unit 10, and when receiving the print start command, decodes the print start command and determines whether it is a double-sided sheet discharge designation (double-sided print command).

If the double-sided path discharge is not designated, the single-sided print command is issued, and therefore the pick roller 50 is pulled from the paper cassette 20.
Picked up with, and sent to the standby roller 35 by the conveying rollers 51a, 51b, 51c, charged by the pre-charger 32, an optical image is written by the optical system unit 33, a latent image is formed, and a toner image is formed by the developing unit 34. Photosensitive drum 31 formed
The toner image of the photosensitive drum 31 is transferred to the surface of the sheet fed by the standby roller 35 in synchronism with the toner image of FIG. Fixed and switchback roller 5
It is sent in five directions, conveyed by switchback roller 55 toward discharge tray 58, discharged by discharge roller 57 to discharge tray 58, and the process returns to the step.

On the other hand, when the double-sided path discharge is designated, the sheet cassette 20 is picked by the pick roller 50, and the conveying rollers 51a, 51b, 51c are sent to the standby roller 35,
It is charged by the pre-charging device 32, an optical image is written by the optical system unit 33, a latent image is formed, and a toner image is formed by the developing unit 34. In synchronization with the toner image on the photosensitive drum 31, the standby roller 35 is used. The toner image of the photosensitive drum 31 is transferred by the transfer / separator 36 to the surface of the paper to be sent,
It is separated from the photosensitive drum 31, fixed by the heat roller fixing device 38, sent in the direction of the switchback roller 55, conveyed by the switchback roller 55 in the direction of the discharge tray 58, and printed by the impeller 54 on the back end of the paper. Carrier path 5
9, the switchback roller 55 feeds the paper to the back surface printing conveyance path 59, and the paper is made to stand by before the standby roller 35 by the conveyance rollers 59a and 59b of the back surface printing conveyance path 59.

Next, the processor 12 operates the counter 13 to start counting at time t ₁ . The processor 12 determines whether or not the print start command from the control unit 10 has been received. If the print start command has not been received, the process proceeds to step. If the print start command is received, the process proceeds to step.

When the processor 12 receives the print start command, it decodes the command and determines whether it is a double-sided sheet feed designation (back side print command). If the print start command is the double-sided paper feed designation, the processor 12 stops counting by the counter 13, resets it, performs back surface printing, and returns to step.

That is, the paper on the back side transport path 59 is sent to the standby roller 35 by the transport roller 59b, and the toner image on the photosensitive drum 31 is transferred to the back side of the sheet sent by the standby roller 35 by the transfer / separator 36. The image is transferred, separated from the photosensitive drum 31, fixed by the heat roller fixing device 38, and sent to the switchback roller 55, and the switchback roller 5
5, the sheet is conveyed in the direction of the discharge tray 58, and the discharge roller 57
Thus, the paper is discharged to the discharge tray 58, and double-sided printing is performed.

On the contrary, if the print start command is not the double-sided sheet feeding designation, the single-sided printing is designated. The processor 12 determines whether the count value t ₁ of the counter 13 has reached a predetermined time, and if not, returns to the step.

When the count value t ₁ of the counter 13 reaches a predetermined time, the processor 12 reports an abnormality to the control unit 10 and sends the sheet waiting on the back side conveyance path 59 to the waiting roller 35. Without printing, the sheet is conveyed in the direction of the discharge tray 58 by the conveyance path 30 and the switchback roller 55, and is discharged to the discharge tray 58 by the discharge roller 57.

Next, the operation of the control unit 10 that has been notified of an abnormality will be described. FIG. 5 is a flowchart of the reprinting process according to the embodiment of the present invention. Upon receiving the abnormality report from the mechanism control unit 11, the control unit 10 reports the abnormality to the host device 6.

The upper device 6 issues the reprint data,
The control unit 10 receives the reprint data, and the mechanism control unit 1
A double-sided printing command and print data are issued to the printer 1, the front side is printed as in the step of FIG.

Then, the back side print command and the print data are issued to the mechanism control section 11, the back side is printed and the paper is ejected as in the step of FIG. Upon receiving the discharge completion from the mechanism control unit 11, the control unit 10 recognizes the reprint completion.

In this way, in the double-sided printing, after the front side printing, the sheet is waiting on the back side printing conveyance path 59,
Wait for the back side print command, and if the back side print command does not come within the predetermined time, the paper remains in the back side print conveyance path 59 for a long time, curls, and the print content is deteriorated. Let

At the same time, in order to invalidate this paper,
The paper is ejected from the back side printing conveyance path 59. Further, in order to reprint the invalidated print storage, the control unit 10 requests the upper 6 for reprint data, and in response to this, causes the mechanism control unit 11 to reprint both sides.

Therefore, the uncurled printed matter can be normally discharged without being normally discharged by being printed on both sides of the curled paper. (b) Description of Other Embodiments In addition to the above embodiments, the present invention can be modified as follows.

In the above-mentioned embodiment, the printing mechanism 3 has been described as an electrophotographic mechanism, but it may be used in other printing mechanisms such as heat fixing (for example, electrostatic recording mechanism) or printing mechanisms in which curling occurs due to printing. Can be used.

The sheet PP is not limited to paper, but other media can be used. Although the printer has been described as the printer, it may be another printer such as a copying machine or a facsimile.

The present invention has been described above with reference to the embodiments.
Various modifications are possible within the scope of the invention, and these modifications are not excluded from the scope of the invention.

[0047]

As described above, according to the present invention,
It has the following effects. If the back side print command is not received within the predetermined time by measuring the staying time of the sheet on the back side conveyance path, the sheet is curled and an error is reported to the control unit.
It is possible to prevent the curled printed matter of poor quality from being discharged normally.

Further, it is possible to prevent the normal discharge of the poor quality printed matter in which the printed contents are deteriorated due to the heat in the apparatus.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of a printing apparatus according to an embodiment of the present invention.

FIG. 3 is a block diagram of an embodiment of the present invention.

FIG. 4 is a process flow diagram of an example of the present invention.

FIG. 5 is a flowchart of a reprinting process according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 1 Printing Device 3 Printing Mechanism 5 Conveying Mechanism 6 Upper Device 10 Control Unit 11 Mechanism Control Unit 20 Paper Cassette 30 Conveying Path of Printing Mechanism 31 Photosensitive Drum (Image Forming Drum) 34 Developing Unit 35 Standby Roller 36 Transfer / Separator 38 Heat Roller Fixing device 54 Impeller 55 Switchback roller 59 Transport path for backside printing

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G03G 15/00 106 H04N 1/00 106 B 7046-5C 1/23 Z 9186-5C

Claims (3)

[Claims] 1. A paper feed unit (2) is controlled by a mechanism control unit (11) in response to a single-sided printing command from a control unit (10).
0), the sheet (PP) is taken out, conveyed by the conveying path (30), printed by the printing mechanism (3) and ejected, and the sheet (20) is ejected from the sheet feeding section (20) in response to a double-sided printing command. P
P) is taken out, conveyed by the conveying path (30), printed by the printing mechanism (3) and conveyed to the back side conveying path (59),
The back side conveyance path (59) from the control section (10) is made to stand by.
The sheet (PP) which has been awaited in response to a sheet feeding instruction from
In a double-sided printing apparatus that feeds paper to the conveyance path (30), prints the back surface by the printing mechanism (3), and discharges the paper, the mechanism control unit (11) supplies the paper to the back conveyance path (59). After the sheet (PP) is discharged, the control unit (1
A double-sided printing device characterized by reporting an abnormality to the control unit (10) when a paper feed command from the back side conveyance path (59) is not received from 0). 2. The mechanism control section (11), after reporting the abnormality, sends the sheet (P) on the back side conveyance path (59).
2. The double-sided printing device according to claim 1, wherein P) is discharged. 3. The double-sided printing apparatus according to claim 2, wherein the control unit (10) transmits a double-sided printing command and reprint data to the mechanism control unit (11) after receiving the abnormality. ..