JPH05297662A - Both-side recording device - Google Patents

Abstract

PURPOSE:To miniaturize the main body of a both-side recording device provided with a reversing path along which a sheet is reversed. CONSTITUTION:The reversing unit 35 is made by bending an outside reversing- guide plate 36 and an inside reversing-guide plate 37 to 180 deg. in the reversing direction, thereby forming the reversing path 38 between them, and the unit is provided on the recording device main body 10. One end 38a of the reversing path 38 of the reversing unit 35 is connected to the rear end of a sheet carry path 19 passing through the recording device main body 10 and the other end 38b of the reversing path 38 is connected to the sheet carry path 19 in front of the recording position (a) of the recording device main body 10 and towards the sheet feeding side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a printer, a copying machine,
The present invention relates to a double-sided recording device that records on both sides of a sheet such as a printing machine.

[0002]

2. Description of the Related Art Conventionally, in a double-sided recording apparatus of this type, for example, a laser printer, one side of a sheet is recorded at a recording position through a sheet conveying path, and the sheet after the one-sided recording is turned upside down through a switchback path of an inversion path. After that, the sheet is again returned to the sheet conveying path through the re-feeding path that largely detours to the sheet feeding side, and recording is performed on the other surface of the sheet at the recording position.

[0003]

However, in the conventional laser printer of this type, since the sheet after one-sided recording is returned from the sheet feeding side to the sheet conveying path through the switchback path of the inversion path and the sheet re-feeding path, the reversal is performed. There is a problem that the path is inevitably long and the printer body becomes large. Therefore,
An object of the present invention is to reduce the size of the recording apparatus main body of a double-sided recording apparatus that has an inversion path that inverts the front and back of a sheet.

[0004]

Therefore, what is stated in claim 1 is, for example, as shown in the following illustrated embodiment,
The sheet S is printed on one side of the sheet S at the recording position a through the sheet conveying path 19, the sheet S after the recording is turned upside down through the reversing path, and is returned to the sheet conveying path 19 to return to the sheet S at the recording position a.
In a double-sided recording device that records on the other side and discharges it,
An inversion path 38 that reverses the sheet S after fixing and returns the leading end to the sheet feeding side and returns to the sheet conveyance path 19 before the recording position B is provided above the sheet conveyance path 19. Is characterized by.

According to a second aspect of the present invention, for example, as shown in the following illustrated embodiment, in the double-sided recording apparatus according to the first aspect, the transport roller 25 before the recording position B is set.
Is provided with a control means for rotating the sheet S faster when it is fed backward from the reversing path 38 toward the sheet feeding side than when it is conveyed to the recording position B.

[0006]

According to the present invention, recording is performed on one side of the sheet S at the recording position B through the sheet conveying path 19, the sheet is reversed upside down in the upper reversing path 38, and the sheet is conveyed again to the sheet conveying path 19 before the recording position B. return. Then, the sheet is conveyed through the sheet conveying path 19, and recording is performed on the other surface of the sheet S at the recording position B, and the sheet is discharged.

According to the second aspect of the invention, the transport roller 2 is faster than when the sheet S is transported toward the recording position B.
5 is rotated to feed the sheet S returned to the sheet conveying path 19 after single-sided recording backward toward the sheet feeding side.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of the entire internal mechanism of a laser printer which is an embodiment of the present invention.

Reference numeral 10 in the figure denotes a printer body (recording apparatus body). The printer body 10 includes an upper structure 10a and a lower structure 10b which can be opened and closed centered around a hinge (not shown).

A photoconductor 11 is provided substantially in the center of the printer body 10. Around the photoconductor 11, a charging device 12, a developing device 13, a developing device 13,
A transfer device 14 and a cleaning device 15 are arranged. And
An optical writer 16 is arranged below the charger 12 and the developer 13. Below the optical writer 16, a paper feed cassette 18 in which the sheets S are set is detachably provided. A sheet feeding roller 20 is arranged near the right end of the sheet feeding cassette 18 in the figure, and a starting end 19a of a sheet conveying path 19 is provided in the vicinity of the sheet feeding roller 20.

The sheet conveying path 19 is provided in the printer body 10.
In the figure, it bypasses the front side on the right side in the figure, passes over the developing device 13, passes through the recording position a between the photoconductor 11 and the transfer device 14, and extends to the back side on the left side in the figure. This sheet transport path 1
In the middle of 9, the reading unit 24 is sequentially arranged in the sheet conveying direction.
While the transport roller 25 is arranged on the front side of the recording position a, the fixing device 26 and the paper discharge roller 27 are arranged on the rear side of the recording position a. The transport roller 25 is provided so as to be rotatable in forward and reverse directions.

On the other hand, outside the printer body 10,
While a manual sheet feeding section 28 is provided on the front side on the right side in the figure, a sheet discharging stack section 29 is provided on the upper surface on the rear side on the left side in the figure.

Similarly, a reversing unit 35 is removably provided on the back side upper surface of the printer body 10 having the paper discharge stack section 29. The reversing unit 35 is provided with a substantially middle portion of two outer and inner reversing guide plates 36 and 37 curved in a reversing direction of 180 degrees, and forming a reversing path 38 between the reversing guide plates 36 and 37. .. The one side 38a of the reversing path 38 is connected to the end 1 of the sheet conveying path 19.
9b is connected and connected, and an inversion path 38 is provided above the sheet conveyance path 19. One of the inversion paths 38a has a first
A switching lever 39 is provided. The first switching lever 39 is
While opening the path from the sheet conveying path 19 to the reversing path 38,
The first position for closing the path from the sheet transport path 19 to the sheet discharge stack section 29, and the reverse path 38 from the sheet transport path 19
The shaft 40 is rotatably provided at a second position where the path to the sheet discharge path 29 is opened while the path to the sheet stack path is closed.

Further, in the middle of the reversing path 38, the pair of conveying rollers 42, 42 are appropriately supported and provided. further,
The other side 38b of the inversion path 38 is provided with the window hole 4 of the apparatus body 10.
Connect to 3 toward the paper feed side. A second switching lever 44 is provided in the window hole 43. The second switching lever 44
Means to close the window hole 43 and the path from the other side 38b of the reversing path 38 to the sheet carrying path 19 while opening the sheet carrying path 19 between the recording position B and the carrying roller 25.
Position and the other side 38 of the reversal path 38 that opens the window hole 43
While a path from b to the sheet conveying path 19 is opened, a shaft 45 is rotatably provided at a second position where the sheet conveying path 19 between the recording position a and the conveying roller 25 is closed.

When recording on the sheet S,
First, the first switching lever 39 and the second switching lever 4
After setting 4 to the first position as shown in the drawing, the sheet feeding roller 20 is driven to feed the sheet S in the sheet feeding cassette 18 in the direction of arrow A. Then, the sheet S passes through the sheet conveying path 19 and is abutted and stopped between the conveying rollers 25 in the middle thereof, and thereafter, the sheet S is fed to the recording position B on the photoconductor 11 at a timing. The photoconductor 11 is driven in the counterclockwise direction as shown by the arrow, and at that time, the surface thereof is uniformly charged by the charger 12, and the laser beam L from the optical writer 16 is irradiated to the photoconductor 11. Form a latent image. This latent image is visualized by toner as it passes through the developing device 13. Then, this visible image is transferred onto the lower surface of the sheet S by the transfer device 14 at the recording position B on the photoconductor 11. After the transfer, the sheet S is further conveyed to the fixing device 26 through the sheet conveying path 19, where heat and pressure are applied to fix the transferred image on the sheet S.

On the other hand, the surface of the photoreceptor 11 after the transfer of the visible image is cleaned by the cleaning device 15.

After the image is fixed, the sheet S is sent out by the sheet discharge roller 27 and sent from the sheet conveying path 19 to the reversing path 38 by the first switching lever 39. Then, the sheet S after single-sided recording is reversed by the conveyance roller pair 42.
The inside of the sheet is conveyed and turned upside down, and the front end of the sheet S is returned to the sheet conveying path 19 from the window hole 43 with the leading end thereof facing the sheet feeding side. At that time, as shown in FIG. 2, the second switching lever 44 is switched to the second position, and the control roller (not shown) causes the transport roller 25 to rotate in the reverse direction faster than in the normal rotation. Then, the sheet S is drawn into the sheet feeding side in the sheet feeding path 19 by the feeding roller 25. Then, the second switching lever 44 is switched to the first position, and the transport roller 25 is normally rotated. Then, the sheet S is fed again onto the photoconductor 11 and recording is performed on the other surface of the sheet S as well. Next, the first switching lever 39 is switched to the second position as shown in the drawing, and the sheet S after double-sided recording is stacked on the paper discharge stacking unit 29.

When manually feeding the sheet, the sheet S is put in the manually feeding section 28 and fed by the sheet feeding roller 47 in the direction of arrow B. Then, the sheet S is put into the sheet conveying path 19, and while the sheet S is conveyed therethrough, recording is performed on the sheet S through the same process as described above, and the sheet S is stacked on the sheet discharge stack section 29.

When reading a document, the document P is inserted from the manual paper feed section 28 as shown in FIG.
Then, the paper feed roller 47 is driven to feed the document P from the manual paper feed section 28 to the sheet transport path 19 and transport it through the reading surface 24a of the reading unit 24 and the elastic roller 48. When passing through the reading surface 24a, the original P is read by pressing it with the elastic roller 48.
The document P after being read passes through between the transport rollers 25, is guided by the second switching lever 44 switched to the second position, and is discharged from the window hole 43 to the outside of the apparatus main body 10.

[0020]

Therefore, according to the present invention, since the sheet after single-sided recording is turned upside down on the reversing path on the upper side of the sheet conveying path and is returned to the sheet conveying path before the recording position, a switchback path is provided. It is not necessary, and the inversion path can be shortened without largely detouring to the paper feeding side, and the recording apparatus main body of the double-sided recording apparatus having the inversion path can be downsized.

According to the second aspect, at the time of recording,
The conveying roller is rotated faster than when the sheet is conveyed toward the recording position, and the sheet returned to the sheet conveying path after single-sided recording is fed backward toward the paper feed side. Can be shortened.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an entire internal mechanism of a laser printer that is an embodiment of the present invention.

FIG. 2 is a state diagram of a laser printer showing a case where a sheet after one-sided recording is reversed by the reversing unit and returned to a sheet conveying path.

[Explanation of symbols]

 19 sheet conveying path 25 conveying roller 26 fixing device 38 reversing path a recording position S sheet

Claims (2)

[Claims] 1. A sheet is recorded on one side of a sheet at a recording position through a sheet conveying path, the sheet after recording is turned upside down through an inversion path and returned to the sheet conveying path, and recording is performed on the other side of the sheet at the recording position and then discharged. In the double-sided recording device, an inversion path is provided on the upper side of the sheet conveyance path, in which the sheet after recording is turned upside down and before the recording position, the leading end is directed to the sheet feeding side and is returned to the sheet conveyance path again. , Double-sided recording device. 2. A conveying roller before the recording position is rotated faster when the sheet is fed backward from the reversing path toward the sheet feeding side than when the sheet is conveyed toward the recording position. The double-sided recording device according to claim 1, further comprising a control unit.