KR100524007B1 - Duplex printing method for printing device - Google Patents

Abstract

In the two-sided printing method of the printing apparatus having a single-sided printing path, a paper inverting unit for inverting the paper passing through the single-sided printing path, and a reverse path for re-feeding the paper inverted in the paper inverting unit to the single-sided printing path The printing method comprising: a first printing step of printing on one side of a sheet of paper conveyed through the single-sided printing path; An inversion step of inverting the paper entered into the paper inversion unit after the one side is printed in the paper inversion unit and transferring it to the double-sided printing path; Detecting whether a leading edge of the paper passing through the duplex printing path passes through a predetermined position of the single-side printing path; And determining whether to perform a print job on the other side of the paper by determining whether the paper is sensed in the duplex printing path within a predetermined reference time from the time when the paper is inverted by the paper inverting unit. Disclosed is a double-sided printing method of a printing apparatus.

Description

Duplex printing method for printing equipment {Duplex printing method for printing device}

The present invention relates to a double-sided printing method of a printing machine.

1 is a schematic view showing a conventional duplex printing apparatus disclosed in Korean Patent Publication No. 10-2000-74328.

Referring to the drawings, the duplex printing apparatus is arranged to align the feed cassette 2 with paper loaded inside the machine main body 1, the pickup roller 3 for feeding the paper sheet by sheet, and the leading end of the picked paper. The resist roller 4 for this is provided. Further, a developing unit 5 for forming an image on the conveyed paper is provided, and a transfer roller 6 is provided in correspondence with the photosensitive drum 5a of the developing unit 5. In front of the transfer roller 6, a fixing unit 7 for fixing an image transferred to a sheet is provided. A discharge roller 8 for discharging the paper which has passed through the fixing unit 7 to the outside is provided on the discharge table 9 side.

In addition, an idle roller 10 is provided on a paper conveyance path. A paper discharge path is formed over the idle roller 10 and the discharge roller 8, and a reverse path for inverting the paper for duplex printing is further provided. On the reversing path, a paper reversing unit 11, a reversing roller 12 for reversing the progress of the paper, and a plurality of feed rollers 13, 14, 15 for reversing the reversed paper to the register roller 4 side are provided. Prepared. In addition, a plurality of position detection sensors 16, 17, 18, 19 for detecting the conveyance state of the paper is provided on the reverse path. Here, driving motors M1 and M2 for driving the inversion roller 12 and the transfer rollers 13, 14 and 15 are provided on the inversion path.

In the above configuration, the pickup roller 3 is rotated during the single-sided printing to pick up the paper loaded in the paper cassette 2. The picked up paper is passed through the register roller 4 to the developing unit 5. The image formed on the photosensitive drum 5a is transferred to the paper passing through the developing unit 5. The paper on which the image is developed is settled at high temperature and high pressure while passing through the fixing unit 7, and then discharged to the discharge tray 9 through the idle roller 10 and the discharge roller 8. In the duplex printing mode, While passing the paper passing through the fixing unit 7 in the idle roller 10, the feed path is switched to the paper inverting unit 11 so that the paper is transferred to the paper inverting unit 11. The paper whose printing surface is switched in the paper inverting portion 11 is conveyed back to the register roller 4 side by the inversion roller 12 and the plurality of feed rollers 13, 14, and 15. In the register roller 4, the paper with the leading edges is printed on the rear side through the same path as in the single-sided printing mode, and the finished paper is discharged to the discharge tray 9 by the delivery roller 8. .

By the way, the conventional duplex printing apparatus having the above-described configuration is complicated by the need to provide a separate paper inverting unit for switching the printing surface of the paper. In addition, as the reversal path becomes longer, additional driving motors M1 and M2 are required for conveying paper, and a plurality of position detection sensors 16, 17, 18, and 19 need to be additionally installed. Will increase. In addition, since the above components must be controlled, a complicated algorithm is required in the control for duplex printing.

The present invention was devised to solve the above problems, and provides a duplex printing method of a printing apparatus which can easily control duplex printing of a sheet while simplifying the structure of the reverse path of the sheet for duplex printing. There is a purpose.

The double-sided printing method of the printing apparatus according to the present invention for achieving the above object comprises a single-sided printing path, a paper inverting unit for inverting the paper passing through the single-sided printing path, and a paper inverted in the paper inverting unit. Claims [1] A double-sided printing method of a printing apparatus having a reverse path for re-transferring to a printing path, comprising: a first printing step of printing on one side of a sheet of paper conveyed through the single-sided printing path; An inversion step of inverting the paper entered into the paper inversion unit after the one side is printed in the paper inversion unit and transferring it to the double-sided printing path; Detecting whether a leading edge of the paper passing through the duplex printing path passes through a predetermined position of the single-side printing path; And determining whether to perform a print job on the other side of the paper by determining whether the paper is sensed in the duplex printing path within a predetermined reference time from the time at which the paper is inverted by the paper inverting unit. .

Here, the second printing step of performing a print job on the other side of the paper when the reversed paper is detected in the duplex printing path within the predetermined reference time.

In addition, if the inverted paper is not detected in the duplex printing path within the predetermined reference time, stopping the print job and performing the jam generating mode;

The predetermined reference time may be a paper transfer time corresponding to the sum of the length of the reverse path, the distance from the start position of the single-sided printing path to the paper sensing position, and the predetermined length margin due to jam occurrence.

In addition, the length margin is preferably a length of 20 to 30mm.

Hereinafter, a duplex printing method of a printing apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view schematically showing a printing device for explaining a two-sided printing method of the printing device according to an embodiment of the present invention. Referring to FIG. 2, the printing apparatus includes a paper feed cassette 21 installed inside the printer body 20 to accommodate paper, and on one surface of the paper picked up by the pickup roller 22 from the paper cassette 21. A single side printing path L1 for printing an image, a paper inversion unit 30 for inverting a sheet past the single side printing path L1 for double-sided printing, and a paper inverted in the paper inverting unit 30 It has a reverse path (L2) for feeding back to the cross-sectional printing path.

At the inlet of the single-sided printing path L1, the driving roller 41 and the plurality of idle rollers 42 and 43 for conveying the paper picked up and entered are installed in contact rotation. In addition, on the single-sided printing path L1, a resist roller 44 for aligning the leading edge of the paper, a paper detecting sensor 45 for detecting leading edge of the paper, and a developing unit 46 for printing an image on the paper ) And a fixing unit 47 for fixing the developed image on the sheet are sequentially installed. That is, the end face printing path L1 includes a pickup roller 22, a driving roller 41, idle rollers 42 and 43, a resist roller 44, a developing unit 46 and a fixing unit 47. Can be distinguished.

The paper inverting unit 30 is provided to invert the paper that is passed through the single-sided printing path (L1) to the paper delivery roller 23. The paper reversing unit 30 passes through a single-sided printing path L1 and discharges the discharge sensor 31 for detecting the leading edge and the trailing edge of the paper toward the discharge roller 23, and the discharge sensor 31 and the discharge roller 23. And a reverse roller 33 and a backup roller 35 provided between the two rollers, and a clutch 36 for selectively driving the reverse roller 33 in reverse rotation. The discharge sensor 31 is an actuator type sensor which is turned on while being rotated by interference with the leading edge of the paper to be conveyed, and is returned after the edge of the paper has passed. The discharge roller 23 is rotated in the paper discharge direction (A). In this embodiment, when the clutch 36 is turned off, the paper is conveyed while being driven in rotation in the discharge direction A by being connected to the drive shaft 36a of the clutch 36. At this time, the reversing roller 33 is driven in the discharge direction (A), the reverse direction can be rotated by being connected to the drive shaft (36a) of the clutch 36 in the reverse direction. In this way, for the reverse rotation of the inversion roller 33, the inversion roller 33 receives the power of the drive shaft 36a in the reverse direction through the idle roller 37. In this way, in order to reverse the reverse roller 33, the clutch 36 is kept in the on state. That is, the drive shaft 36a when the clutch 36 is turned on is connected to the idle roller 37, and the discharge medium is turned off. It is connected to the roller 23. The clutch 36 may be configured to selectively move the drive shaft 36a with, for example, a solenoid type drive unit to move the drive shaft 36a. The drive shaft 36a receives power from a main motor not shown through a predetermined gear train. In particular, even if the position of the drive shaft 36a is changed by the on / off operation of the clutch 36, the drive shaft 36a moves to the gear connected to the gear train receiving power to continuously receive power in the same direction. This power transmission configuration is a well-known technique throughout the industry, so detailed description thereof will be omitted.

The paper inverted by the paper inverting unit 30 is transferred to the inversion path L2. A plurality of idle rollers (51, 53, 54) are installed in this inversion path (L2) so as to be sequentially rotated together with the backup roller, and the paper conveyed while being in contact with the drive roller 41 is rotated in one-sided printing path ( Guide rollers 54 and 55 are further provided to enter L1. Here, the inversion path (L2) is not provided with a sensor for detecting the position of the paper or a sensor for detecting the jam occurrence. That is, the inversion path L2 represents a path from the inversion roller 33 to the plurality of idle rollers 51, 52, 53 and the guide rollers 54, 55 driven by the driving roller 41. In Fig. 2, reference numeral 26 denotes a laser scanning unit (LSU) for scanning a laser beam on the photosensitive drum 46a of the developing unit 46.

The duplex printing method using the printing apparatus having the above configuration will be described with reference to FIGS. 2 and 3 as follows.

First, the printing apparatus is capable of selectively performing both the so-called single-sided printing mode and the double-sided printing mode, and determines whether the current printing operation state is the single-sided printing mode or the double-sided printing mode according to the input print command (S10). When it is confirmed in the duplex printing mode in this step (S10), it is determined whether the side of the paper to be printed is one side or the other side (S11). If it is determined that the surface of the paper to be printed is the other side, since one surface is already printed, the paper is transferred from the single-sided printing path L1 to the paper inverting unit 30 to invert the paper (S12).

That is, the paper inversion step S12 will be described in detail. First, when the paper is transferred from the single-sided printing path L1 to the paper inversion unit 30, the discharge sensor 31 is shown in FIG. The position of the paper is sensed by being rotated by being interfered with the front end (S20). In the step S20, if the paper is not detected even after a predetermined time has elapsed in the discharge sensor 31, it is determined that the jam has occurred on the single-sided printing path L1 to perform a series of jam generation processing modes S21. do. That is, in the step S21, the jam is generated through a process known in advance or a predetermined operation, for example, jam paper processing (jam removal by the operator) and malfunction check through jam occurrence error display and notification. It will be resolved.

On the other hand, when the paper passes normally, the discharge sensor 31 is turned on until the paper passes completely through the discharge sensor 31. At this time, the clutch 36 is in an off state, and the drive shaft 36a is connected to the discharge roller 23 to rotate the discharge roller 23 in the paper discharge direction A. FIG. Therefore, the sheet is conveyed in the discharge direction A by a predetermined amount by the discharge roller 23.

In addition, in order to determine whether the rear end of the paper is normally passed through the discharge sensor 31, it is determined whether the discharge sensor 31 returns to the off state (S22). Even in this case, if the output sensor 31 does not return to the off state even after the time required for the paper to pass normally, it is determined that the jam has occurred, and the same jam generation processing mode S23 as in step S21 is performed. do. That is, the continuous discharge of the discharge sensor 31 means that the jam is generated or an error has occurred while passing through the discharge sensor 31, and the step S23 is performed.

On the other hand, as shown in FIG. 5, when it is returned to the normally off state from the discharge sensor 31 in the step S20, the clutch 36 is turned on to idle the driving shaft 36a of the clutch 36. (37) (S24). Then, the reverse roller 33 is driven in reverse rotation to convey the paper in the reverse direction. At this time, the reversed paper conveyed enters the reverse path L2 and is conveyed. Then, it is determined whether the time that the clutch 36 is kept in the ON state is maintained for a time corresponding to the standard length of the paper (S25). Here, when it is determined that the on state of the clutch 36 has elapsed for a predetermined time (standard length of paper), the clutch 36 is switched back to the off state (S26). Then, as shown in Fig. 6, the paper is transferred to the reverse direction by the reverse roller 33, both the state is passed through, the leading end of the paper enters between the drive roller 41 and the idle roller 54 and is conveyed do. That is, the sheet to be conveyed is fed to the end face printing path L1 by the driving roller 41 after passing through the reversing roller 33 by the front end being bitten by the driving roller 41 before the rear end passes the reversing roller 33. Is entered.

After the clutch 36 is turned off as described above, the duplex printing mode S13 for printing on the other side of the paper is performed. In the duplex printing mode S13, the paper sensor 45 before performing a series of printing processes for forming an image on the photosensitive drum 46a using a charging means and a laser scanning unit 26, etc., not shown. In step S31, it is determined whether the front edge of the paper is detected. In particular, by determining whether the paper is detected at a time elapsed from the time when the paper is reversed in the paper inverting unit 30 in the step (S31), whether the paper jam occurs in consideration of the time required for the paper transfer time. Will be judged. That is, when the paper is not detected by the sensor 45 even after the predetermined time has elapsed, the jam processing mode S32 is performed in consideration of the occurrence of a jam or other error. In this case, the printing operation is naturally stopped. On the other hand, as shown in FIG. 7 after a predetermined time, when the front end of the paper passes through the detection sensor 45 and the paper is detected, the laser scanning unit 26 and the developing unit 46 based on the detection signal. After driving the back and the like to form an image, the image is printed on the other side of the paper (S33). Here, the predetermined period is preferably the distance (L3) from the start position of the cross-sectional printing path (L1) starting from the inversion path (L2) and the driving roller 41 to the paper sensing position (position of the paper sensor). And a paper transfer time corresponding to the distance of the sum of all of the predetermined jam margins. That is, the time taken for the paper to be conveyed at the normal conveying speed is determined at the predetermined speed. Here, in particular, the jam margin is given a length of 20mm to 30mm, so that even if the paper margin is not detected by the paper sensor 45, even after the spare time for the jam margin is determined that the jam occurred.

In this way, when the two-sided printing mode is finished by printing on the other side of the paper, it is determined whether to continue printing (S14), and the single-sided printing operation is performed on one surface of the paper continuously picked up (S15). After the single-sided printing is performed, it is determined whether to continue printing (S16). If the printing is continued, it is determined whether to print the other side or the single-sided printing through another paper from the step S10. The process will be carried out.

On the other hand, as described above, by inverting the paper normally without having a drive roller or drive motor driven for the transport of the paper on the reverse path (L2) for duplex printing, or a separate sensor for checking the occurrence of jams, It can be transported and can even detect jams. Therefore, a complicated configuration is unnecessary as in the prior art, and the cost can be reduced and the control algorithm of the printing operation can be easily configured through a simple configuration.

According to the two-sided printing method of the printing apparatus of the present invention as described above, the paper inversion path for the two-sided printing is short, the drive path, the resist roller and the jam generation detection sensor for transporting the paper is unnecessary in the reverse path configuration This is simple, and therefore, the cost can be reduced.

In addition, there is an advantage that the duplex printing can be smoothly performed by detecting the transfer state of the paper and the occurrence of the jam by using the sensors provided on the single-sided printing path and the paper reversing unit without a separate sensor.

1 is a schematic configuration diagram showing a conventional printing device.

2 is a schematic configuration diagram of a printing apparatus for explaining a duplex printing method according to an embodiment of the present invention.

Figure 3 is a flow chart illustrating a duplex printing method of the printing apparatus according to an embodiment of the present invention.

4 to 7 are schematic diagrams illustrating a process of performing duplex printing according to the flowchart shown in FIG. 3.

<Description of Symbols for Major Parts of Drawings>

20.Print body 21.Paper cassette

22..pick-up roller 23 .. badge roller

30. Paper transfer area 31. Badge sensor

33..Reverse roller 36..Clutch

41. Driving roller 44. Resist roller

45. Paper detection sensor 46. Developing unit

47..Fixing unit

Claims (5)

A paper reversing unit including a pickup roller, a driving roller for transferring paper, a resist roller, a printing unit including a developing unit and a fixing unit, and a reversing roller for reversing the paper passing through the single-side printing path; In the double-sided printing method of the printing apparatus having a reverse path from the paper reversing roller to the plurality of idle rollers and the driving roller in order to convey the paper reversed in all in the single-sided printing path, A first printing step of printing on one surface of the paper being transported through the single-sided printing path; An inversion step of inverting the paper entered into the paper inversion unit after the one side is printed in the paper inversion unit and transferring it to the double-sided printing path; Detecting whether a leading edge of the paper passing through the duplex printing path passes through a predetermined position of the single-side printing path; Determining whether to perform a print job on the other side of the paper by determining whether the paper is detected in the duplex printing path within a predetermined reference time from the time when the paper is inverted by the paper inverting unit; And And a second printing step of performing a print job on the other surface of the paper when the inverted paper is detected in the duplex printing path within the predetermined reference time. delete 2. The printing apparatus of claim 1, further comprising: stopping a printing job and performing a jam generation mode when the inverted paper is not detected in the duplex printing path within the predetermined reference time. 2. How to print. The method of claim 1, wherein the predetermined reference time is, And a paper transfer time corresponding to the sum of the length of the inversion path, the distance from the start position of the single-sided printing path to the paper sensing position, and the predetermined length margin due to the occurrence of jams. 5. The method of claim 4, wherein the length margin is 20 to 30 mm in length.