JPH08225216A - Electrophotographic printing device - Google Patents

Abstract

PURPOSE: To fix the paper size, improve the effective printing speed, and stabilize the paper conveying property in an electrophotographic printing device printing the print data of multiple sizes. CONSTITUTION: This electrophotographic printing device is provided with the first paper conveyance path 50 having a paper cutting mechanism cutting the printed paper in half and a paper aligning mechanism aligning the cut paper in the order of the printed data and the second paper conveyance path 51 conveying the printed paper without cutting it. A switching means 52 is operated in response to the printing size data sent from a controller 25 to switch the paper conveyance paths 50, 51.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic printing apparatus for printing print data of a plurality of sizes.

[0002]

2. Description of the Related Art As an example of a conventional electrophotographic printing apparatus, a high-speed cut sheet printing apparatus capable of double-sided printing is shown in FIG.
This will be described using the block diagram of A character image is written as an electrostatic latent image by laser light on the photosensitive drum 5 that is uniformly charged by the charger 6. Toner is applied to the electrostatic latent image by the developing device 7 to form a visible image. On the other hand, the paper 4 is picked up by the pick belt 2 from the hopper 1 and sent to the transfer portion by the transport roll 3. The toner image on the photosensitive drum 5 is transferred onto the paper 4 by the transfer device 8. The paper 4 is separated from the photosensitive drum 5 by the peeling device 9, and the conveyor belt 1
0 is sent to the fixing unit. The heat roller 11 and the backup roller 12 pressurize and heat the toner so that the toner is fixed on the paper. In the case of single-sided printing, the paper is sent to the transport rollers 13 and 14, and the paper is stored in the stacker 19 by the paddle 18. In the case of double-sided printing, the transport rollers 13 and 14 feed the switchback 16, the transport roller 15 reverses the sheet, and the transport roller 17 feeds the back surface of the sheet. After being fixed in the same manner as the paper surface, the paper is stored in the stacker 19. The sheet conveying rollers need to be arranged at the shortest sheet length, but they are partially omitted.

Next, the operation when printing print data of a plurality of sizes will be described. For example, when the print data sizes are A3 and A4, it is necessary to prepare A3 paper and A4 paper. One hopper can handle two types of paper, but it takes a lot of time to replace the paper. Generally, two hoppers are required. For example, set A3 paper in the hopper 1 and use the pick belt 2 to
Pick the paper. Set A4 paper in the hopper 22,
A4 paper is picked by the pick belt 23. Also,
Printing efficiency can be improved by preparing two stackers for each paper size.

For example, the stacker 19 is set for A3 sheets, and the stacker 21 is set for A4 sheets. Controller 25
The print size data is sent, and the paper size data corresponding to the size is returned. From controller 25
When the 3 print data is sent, the hopper 1 is set for A3 paper, and the stacker 19 returns information that A3 paper can be supported. As a result, A3 paper is picked up from the hopper 1 and stored in the stacker 19. Controller 2
When A4 print data is sent from 5, the hopper 22
A4 paper is picked up and stored in the stacker 21.

[0005]

Even in the conventional cut sheet printing apparatus, it is possible to print the print data of a plurality of sizes, but there are the following problems. (1) When printing multiple sizes of print data alternately, after the paper picked from the hopper is stored in the stacker, the paper size is changed and the paper is picked from another hopper. Will be significantly reduced. (2) To print print data of multiple sizes,
It is necessary to prepare paper of multiple sizes, which increases the management and operation cost of paper. (3) Since plural sizes of paper are conveyed, various switching mechanisms are required in the paper width direction and the paper length direction, and it is difficult to stably convey plural sizes of paper.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide an electrophotographic printing apparatus which has improved performance when printing print data of a plurality of sizes.

[0007]

The above-mentioned object is to cut a printed sheet into halves, and to convey the cut two pieces of sheets by aligning them in the order of print data and conveying them. And a second paper transporting path for transporting the sheet without cutting, and selecting either the first paper transporting path or the second paper transporting path according to the size of print data. It

[0008]

According to the present invention, it suffices to prepare one kind of paper size, so that the effective printing speed can be improved and the paper transportability can be stabilized.

[0009]

Embodiments of the present invention will be described with reference to FIGS. 1, 3 and 4. FIG. 1 shows an embodiment of the present invention. FIG. 3 is a block diagram of a cut sheet printing device, FIG. 3 is a perspective view showing an embodiment of a paper cutting mechanism, and FIG. 4 is a principle view showing an embodiment of a paper aligning mechanism. In FIG. 1, the same members as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

As in the prior art, the size of print data is A
The case of 3 and A4 will be described. In the present invention,
In order to print the print data of two sizes, one kind of paper and one hopper should be prepared. That is, only A3 paper is set in the hopper 1. When printing A4 size print data, by performing 2-up printing on A3 paper, cutting the printed paper in half, and arranging the cut two pieces of paper in the print data order and storing them in the stacker. , A4 size print data is printed on A4 paper.

The 2-up printing function means that 2 sheets are printed on one sheet.
This is a function to print the print data for one sheet or two pages at the same time. For example, the A3 paper is laterally fed and the print data for two A4 papers is simultaneously printed. The following are possible advantages of 2-up printing. (1) Improving the printing speed For example, comparing the case where A3 paper is horizontally fed and 2-up printing for two A4 sheets is performed and the case where A4 sheets are horizontally fed at the same paper feeding speed, The printing speed during up-printing is (A4 paper length 210 mm / A3 paper length 297
mm) x 2 sheets = 1.41 (times). (2) Reduction of printing cost For example, in the above case, the cost of printing one A3 sheet is A
Since it is possible to print two sheets of four A4 sheets, it is possible to reduce the printing cost per A4 sheet. Thus, 2-up printing has some advantages. Depending on the print size data sent from the controller 25,
Either one of the paper transport path 50 and the paper transport path 51 is selected. When the print size is A4, the paper transport path 50 is selected. When the print size is A3, the paper transport path 51 is selected. When print data of A4 size is sent from the controller 25, 2-up printing is performed on A3 paper.

The A3 paper, which has been double-printed by single-sided printing or double-sided printing, is conveyed through the sheet conveying path 50 by the switching valve 52. In the paper conveyance path 50, the A3 paper is divided into two by the paper cutting mechanism into A4 paper, and the two pieces of A4 paper are aligned by the paper alignment mechanism in the order of print data, sent by the paddle 20 and stored in the stacker 21.

The paper cutting mechanism has a sensor 30 for detecting the amount of paper position deviation in the paper width direction and a circular slitter composed of a circular slitter upper blade 32 and a circular slitter lower blade 33 for cutting the A3 paper in half. It is composed of a unit 34 and conveyance rolls 31 and 35 provided before and after the circular slitter unit 34 for fixing and conveying the sheet at the sheet cutting section. Further, details of the paper cutting mechanism will be described with reference to FIG. The circular slitter upper blade 32 and the circular slitter lower blade 33 are lightly contacted with each other, and are rotated by the circular slitter drive motor 45 in opposite directions at the same rotational speed via a gear (not shown). The rotation speed of the circular slitter is generally set higher than the paper conveyance speed.
The circular slitter unit 34 has a structure that can be moved in the paper width direction by a unit moving motor 46 via a belt 47. A CCD or the like is used as the sensor 30 to detect the amount of paper position deviation in the paper width direction as an analog amount. A signal from the sensor 30 is input to a microcomputer (not shown), and when the position of the A3 sheet is displaced, the unit moving motor 46 is driven so that the circular slitter is located at the center of the A3 sheet. 34 is moved in the paper width direction. The position of the circular slitter unit 34 is detected by a sensor (not shown), and the unit drive motor 46 is feedback-controlled. Also, A
When printing a cut sheet of a size different from three sheets, the circular slitter unit 34 is moved in the sheet width direction in the same manner as described above so that the circular slitter is located at the center of the print sheet according to the sheet size data. .

Next, the sheet aligning mechanism will be described with reference to FIG. As shown in Fig. 4, for A3 paper after 2-up printing
Two sheets of print data are printed in the order of (1) and (2). One piece on which the data of (1) is printed is sent through the carrying path 42 by the carrying rollers 36, 37, 38. The piece on which the data of (2) is printed is the width-shifting conveyance roller 39,
40 and the conveyance roller 41 to move the widthwise conveyance path 43 (1)
Data is sent side-by-side to the printed strip. At the joint between the transport path 42 and the widthwise transport path 43,
One piece on which the data of (1) is printed and one piece on which the data of (2) is printed are stacked in the print data order (in the order of (1) and (2)), and are fed by the merging section conveying roller 44. Paddle 20
Are stored in the stacker 21.

A3 size print data is the controller 2
When sent from A.5, A3 size printing is performed on A3 paper. The A3 paper after printing is sent to the paper conveyance path 51 by the switching unit 52 and stored in the stacker 19 by the switching unit 53. In this embodiment, the paper transport path 51 and the paper transport path for double-sided printing are partly shared, and the switching means 53 switches the paper transport path.

[0016]

According to the present invention, the above-mentioned structure has the following effects. (1) When the print data of two different sizes are printed alternately, the print data size can be switched without reducing the execution print speed. (2) Since it is only necessary to prepare paper of one size, it is possible to reduce paper management and operation costs.
In addition, even if the size of the print data changes, the size of the paper to be conveyed is fixed to one type, which eliminates the need for various switching mechanisms for the paper width direction and the paper length direction in the paper conveyance path for printing, thus ensuring stable operation. The secured paper transport is ensured. (3) Since only one hopper needs to be prepared, the size and cost of the device can be reduced. Furthermore, since the paper size is fixed, the reliability of the paper pick is improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an electrophotographic printing apparatus of the present invention.

FIG. 2 is a schematic configuration diagram showing a conventional technique.

FIG. 3 is a perspective view showing an embodiment of a paper cutting mechanism.

FIG. 4 is a principle view showing an embodiment of a paper aligning mechanism.

[Explanation of symbols]

1 is a hopper, 19 and 20 are stackers, 25 is a controller, 34 is a circular slitter unit, 42 is a transport path, 43
Is a widthwise conveyance path, 50 is a paper conveyance path, 51 is a paper conveyance path, and 52 and 53 are switching means.

Front page continuation (72) Inventor Kazutoshi Ohara 1060 Takeda, Hitachinaka City, Ibaraki, Hitachi Koki Co., Ltd. (72) Inventor Masaru Kawamoto 1060 Takeda, Hitachinaka, Ibaraki Hitachi Koki, Ltd.

Claims (1)

[Claims] 1. A first paper feed path for cutting the printed paper in half and aligning the cut two pieces of paper in the order of print data, and a first paper feed path for feeding the printed paper without cutting. An electrophotographic printing apparatus, characterized in that two paper conveyance paths are provided, and either the first paper conveyance path or the second paper conveyance path is selected according to the size of print data.