JPH0356355A - Form curl correcting device for recorder - Google Patents

Abstract

PURPOSE:To correct a form in curl in the middle of carrying and make a stack condition good by providing a swing arm oscillating around a roller shaft of a main roller as the center, and a second sub-roller which is supported with the swing arm and rotated dependently by pushing to the main roller and carries the form between those. CONSTITUTION:A swing arm 48 is oscillated in accordance with a kind of from or a custody condition thereof, second sub-rollers 44... are revolved for changing an aperture angle with first sub-rollers 43 ..., and a contact angle of the form against the main roller 36 is adjusted. It is possible thereby to correct the form in curl in the middle of carrying and to make the stack condi tion good.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention can be used in recording devices that record on paper, such as printers, copying machines, and facsimiles.

More specifically, the present invention relates to a paper curl correction mechanism for correcting curls of paper after recording during paper conveyance in the recording apparatus.

Traditionally, recording devices such as laser printers that record on paper using an electrophotographic method transfer the image on the transfer drum to the paper, and then apply heat and pressure to the paper. Fix the transferred image. For this reason, depending on the type of paper and its storage conditions, curls may occur on the paper after fixing.

Problem to be Solved by the Invention When the curled paper is ejected as it is, for example, the stack of paper 2 on the tray 1 becomes uneven as shown in Fig. 4, and sometimes as shown in Fig. 15. There is a problem in that some of the sheets 2a are dropped and the stack condition is significantly deteriorated. On the other hand, when the paper is reversed and fed again in order to record on both sides, the leading edge of the paper collides with various places on the conveyance path, preventing smooth conveyance.
As shown in the figure, there are problems in that black lines 3 are generated on two sheets of paper, and that the sheet is not brought into sufficient contact with the transfer drum, resulting in poor transfer.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a paper curl correction mechanism for a recording apparatus that corrects the curl of paper during transport of the paper and eliminates such conventional problems.

Means for Solving the Problems Therefore, the paper curl correction mechanism of the recording apparatus according to the present invention, as set forth in claim 1, includes a main roller 36 that rotates in the paper feeding direction, for example, as shown in the illustrated embodiment below.
. . . and the first auxiliary roller 43, which rotates as a result of pressing against the main roller 36, and conveys the paper between them.
. . . and a swing arm 48 that swings around the roller shaft 37 of the main rollers 36 . A second sub-roller 44 that rotates and conveys the paper therebetween; and a second sub-roller 44 between the main roller 36 and the first sub-roller 43;
. . . guide plates 53 for guiding the paper along the outer periphery of the main roller 36 .

Further, the paper curl correction mechanism of the recording apparatus according to the present invention recited in claim 2 is further provided with a fulcrum point as shown in the following illustrated embodiment. a paper guide 56 that is swingable around the main roller 36 and the second auxiliary roller 44 and guides the paper sent out between the main roller 36 and the second sub-roller 44; the paper guide 56 and the swing arm 48; and the second sub-roller 44.
・Link 62 that moves the paper guide 56 in conjunction with
・62.

In the paper curl correction mechanism according to claim 1,
Swing arm 4 depending on the type of paper and its storage situation.
8, the second sub-roller 44 revolves, and the opening angle between the first sub-roller 43 and the main roller 36 is changed. Adjust the wrapping angle.

In addition, in the paper curl correction mechanism according to the second aspect, the paper guide 56 is moved in conjunction with the revolution of the second sub-roller 44, and the main roller 36... The paper that has passed between the sub rollers 44... is smoothly guided by the paper guide 56.

Embodiment-1 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 13 shows a schematic structure of a laser printer. The illustrated laser printer includes a recording section 10, a paper ejecting section 11, and a paper refeeding section 12 inside. On the other hand, on the outside, there are 2 on the right side.
Two paper feed cassettes 13 are mounted in two stages, a face-down paper discharge tray], 4 is mounted on the top surface, and a face-up paper tray 1-ray 15 is mounted on the left side.

In the recording section 10, an electrophotographic process of charging, exposure, development, transfer, and cleaning is repeated to form an image on the surface of the transfer drum 16. On the other hand, the paper fed out from the paper feed force sets 1 to 13, 13 is fed into between the transfer drum 6 and the transfer device 18 with timing taken by the register 1-roller 7. Then, the image on the transfer drum A 1 6 is transferred by the transfer devices J and 8 to record on the paper, and after recording, the fixing device 19 applies heat and pressure to fix the transferred image,
The paper is sent to paper ejection department 1.

In the sheet discharge section 1, the paper is conveyed by feed rollers 20, guided by a switching member 21, and further switched by a switching member (not shown), and the paper is discharged face down at the discharge port 22. The paper is discharged onto the tray 4 or onto the face-up paper discharge tray 15 by the wandering paper roller 23 . Alternatively, the switching member 21 is used to switch, and the paper is sent through the paper curl correction mechanism 24 according to the present invention to the paper refeeding section 2 by the feed rollers 25 .

In the paper refeeding section 2, the paper is guided by the switching member 26 and sent to the switchback section 27, where it is temporarily stopped and at the same time the switching member 26 is switched, and this time it is reversed and sent to the refeeding path 28.
The paper is fed into the recording department, transported by the feed rollers 29, and sent out again to the recording department.

Then, the registration roller 7 . Thereafter, the paper is similarly sent to the paper discharge section 1 through the fixing device 9, and the paper is discharged onto the face-down paper discharge tray 14 or the face-up paper discharge tray 15.

By the way, the paper curl correction mechanism 24 according to the present invention provided in the above-mentioned laser printer has a detailed structure as shown in FIGS. 1 to 3. The symbols 32 and 32 in the figure are
This is the side plate. Between the side plates 32, 32, the roller shafts 33, 33 of the feed rollers 207, etc. mentioned above are rotatably hung.

Also, a paper guide 3 guides the paper from the feed rollers 20 to the paper curl correction mechanism 24.
Multiply 4.35.

The paper curl correction mechanism 24 is provided with a main roller 36 that rotates in the paper feeding direction. Main roller 36...
. . . connects both ends of the roller shaft 37 with brackets 38 and 3.
Supported by 8. Brackets 38, 38 are screws 39...
Attach them to the side plates 32 and 32, respectively. Opposing long holes 38a are formed in both the brackets 38, 38. Then, inside those long holes 38a, 38a,
Bearings 41 and 4 are slidably provided to support both ends of the roller shaft 40, respectively, and the bearings 41 and 4l are attached to the roller shaft 37.
Compression springs 42, 42 are provided that bias toward. The roller shaft 40 supports the first sub-rollers 43 . The first auxiliary rollers 43 . . . press against the main rollers 36 . The main rollers 36 are also pressed against the second sub-rollers 44 for driven rotation, and the paper is similarly conveyed between them. The second sub-roller 44... is a roller shaft 45
I support it. The roller shaft 45 has a second sub-roller 44...
... Attach ring 46 ... between them. Both ends of the roller shaft 45 are supported by a swing arm 48 via bearings 47, 47, respectively. Bearing 47.4
7 is slidably provided in the long holes 48a, 48a of the swing arm 48. Then, these bearings 47, 47 are urged toward the roller shaft 37 by compression springs 49, 49, respectively. Similarly, the compression springs 49, 49 are connected to the elongated holes 48a,
48a.

The swing arm 48 swings around the roller shaft 37 of the main rollers 36. It has a handle portion 48b at one end. The other end has engaging protrusions 48e and 48c. Then, the engaging protrusions 48c, 48c are connected to the arc-shaped tooth portions 50a, 50 of the detent blocks 50, 50, respectively.
Engages with 50a. The detent block 50/50 is
It is supported by leaf springs 52, 52 attached to the side plates 32, 32, respectively, with screws 5l. And the first sub roller 4
A plurality of guide plates 53 are attached to the roller shaft 40 of 3...
. . . one end is wrapped around the main roller 36 . . .
・Extend them along the outer periphery of the ring 46
``...'' I support him by putting him on second place. Then, from between the main roller 36... and the first sub-roller 43..., the main roller 36... and the second sub-roller 44...
. . . The paper is guided along the outer periphery of the main roller 36 .

Between the side plates 32 and 32, there are a main roller 36 and a second sub-roller 44 of the paper curl correction mechanism 24.
・Paper guides 56 and 57 that guide the paper sent out through the space are spanned. Further, the roller shafts 58 are rotatably spanned. The roller shafts 58, 58 support the above-described feed 1 to roller 25, which send out the paper guided by the paper guides 56, 57.

If the curl of the paper is small, the handle part 48
b, swing the swing arm 48 against the leaf springs 52, 52, revolve the second sub rollers 44, and rotate the second sub rollers 43 as shown in FIG. Bring it closer to... Then, the opening angle between the secondary roller 43 and the main roller 36 is made smaller. The winding angle of the paper is made small, and the paper is sent out at a small angle θ■ with respect to the paper guide 56, as shown in FIG. On the other hand, when the curl of the paper is large, the swing arm 48 is swung in the opposite direction by holding the handle 48b, and the second sub rollers 44 are revolved to rotate the first sub roller 44 as shown in FIG. Separate from the sub roller 43. Then, the opening angle between the first sub-roller 43 and the main roller 3 is increased.
6. Increase the winding angle of the paper to the 4th...
As shown in the figure, the angle θ2 is large with respect to the paper guide 56.
Send it out. As a result, the paper is largely warped in the opposite direction to the curling direction, and the curl of the paper is corrected.

FIGS. 5 to 7 show another embodiment that is a partial improvement of the embodiment shown in FIGS. 5 to 4. Fifth
In the embodiment shown in the figures through FIG. 7, the paper guide 56 is swingable about studs 6l and 6 which are set up on the side plates 32 and 32, respectively. At the same time, the paper guide 56 and the swing arm 48 are connected by links 62, 62, and the paper guide 56 is moved in conjunction with the second auxiliary rollers 411-4.

As a result, when the curl of the paper is small, the paper is held at a small angle 03 with respect to the paper guide 56 as shown in FIG.
Send it out. On the other hand, when the curl of the paper is large, the swinging of the swing arm 48 and the movement of the swing arm 48 are transmitted to the paper guide 56 via the links 62, 62.

Then, the paper guide 56 also swings in conjunction with the second auxiliary rollers 44, and the paper is sent out at a slightly larger angle 04 as shown in FIG. This angle θ, can be made smaller than the angle θ2 in FIG. Therefore, in the embodiments shown in FIGS. 5 to 7, it is possible to easily transport the paper and prevent paper jams from occurring.

In the embodiment described above, the swing arm 48 was manually swung. However, as shown in FIGS. 8 and 9, it is also possible to swing automatically. That is, a long hole 48d is formed at the tip of the swing arm 48. Then, a pin 66 placed at one end of the lever 65 is fitted into the elongated hole 48d. The lever 65 is rotatable about a shaft 67 erected on one side plate 32, and is normally rotated counterclockwise in the figure by the biasing force of a tension spring 68. and,
The other end of the lever 65 is a plunger 70 of the solenoid 69.
It becomes connected to. As a result, when the curl of the paper is small, for example, by selectively operating the selection switch on the operation panel, the solenoid 69 is actuated to attract the plunger 70, and the lever 65 is rotated against the biasing force of the tension spring 68. The swing arm 48 is then swung counterclockwise in the figure, and the second sub-roller 44 revolves around the first sub-roller 43 as shown in FIG. Bring it closer. In this way, the opening angle with respect to the first auxiliary rollers 43 is made small, and the winding angle of the paper with respect to the main rollers 36 is made small. On the other hand, when the paper is curled significantly, for example, by selectively operating the selection switch on the operation panel, the operation of the solenoid 69 is stopped, the plunger 70 is pulled out by the biasing force of the tension spring 68, and the lever 65 is rotated. The swing arm 48 is then swung clockwise in the figure, and the second auxiliary rollers 44 are revolved and separated from the first auxiliary rollers 43 as shown in FIG. . Then, the opening angle with the first sub-rollers 43 is increased, and the winding angle of the paper with respect to the main rollers 36 is increased. Then, the paper is largely warped in the opposite direction to the curl direction to correct the curl of the paper.

At this time, as in the embodiment shown in FIGS. 5 to 7,
As shown in FIGS. 10 and 11, the paper guide 56
The paper guide 56 and the swing arm 48 are connected by links 62, 62, and the second auxiliary rollers 44 and The paper guide 56 is moved in conjunction with the main roller 36 and the second auxiliary roller 44 to smoothly guide the paper sent out between the main roller 36 and the second sub roller 44. You can also do this. Fig. 0 shows when the paper curl is small, and Fig. 11 shows when it is large. The reference numerals in the figure are the same as those used for the corresponding parts in FIGS. 8 and 9, and redundant explanation will be omitted.

FIG. 12 shows a mechanism for automatically detecting paper curl. In the figure, 19 is a fixing device shown in FIG. 3, and 20 is a feed roller also shown in FIG. 3. Paper conveyance guides 73 are provided between them, and the conveyance path 7
Shape 4. Then, one end of the filler 75 is put into the conveyance path 74. The filler 75 is rotatable about a shaft 76 and its other end is inserted into a vane-shaped photosensor 77. As a result, when the curled paper passes through the conveyance path 74, the paper touches the filler 75 and rotates it, removing the other end of the filler 75 from the photosensor 77. Then, curling of the paper is detected and, for example, the above-described solenoid 69 is deactivated to create a state as shown in FIG. 9 or FIG. 11. When the paper is not curled, the paper does not touch the filler 75 and does not rotate it. Therefore, in that case, the solenoid 69 is operated to create a state as shown in FIG. 8 or FIG. 10.

Therefore, according to the present invention, the curl of the paper can be corrected during conveyance, the stack condition can be made good -15, and the recording condition can be improved by eliminating black streaks and transfer defects.

According to the invention as set forth in claim 2, it is possible to smoothly convey the paper after the curl correction without jamming or the like.

[Brief explanation of drawings]

The 1st construction drawing is a diagram of a paper curl correction mechanism which is an embodiment of the present invention, 2nd drawing is a perspective view thereof, and 3rd drawing is an arrow A in the 2nd drawing.
FIG. 4, a side view seen from the direction, is an explanatory diagram of the operation of the paper curl correction mechanism. Fig. 5 is a diagram of a paper curl correction mechanism which is another embodiment that is a partial improvement of the embodiment shown in Figs. 1 to 4, Fig. 6 is a side view thereof, and Fig. 7 is an explanatory diagram of its operation. FIG. 8 is a diagram of a paper curl correction mechanism according to another embodiment, and FIG. 9 is an explanatory diagram of its operation. FIG. 10 is a diagram of a paper curl correction mechanism as yet another embodiment;
FIG. 11 is an explanatory diagram of its operation. FIG. 2 is a diagram of a paper curl detection mechanism that can be used in the paper curl correction mechanism of the present invention. FIG. 13 shows a paper curl correction mechanism according to the present invention.
6- is a general configuration diagram of a laser printer that can be used. FIG. 14 and FIG. 5 are explanatory diagrams showing a conventional stacked state of curled paper, respectively, and FIG. 16 is a plan view of paper showing a recording state of conventional curled paper. 36... Main roller, 37...
・Roller shaft of main roller, 43... First sub-roller, 44... Second sub-roller, 48...
Mountain...Swing arm, 53...Guide plate, 56...Paper guide, 62...
·····Link.

Claims (1)

[Scope of Claims] 1. A main roller that rotates in the paper feeding direction, a first sub-roller that presses against the main roller and rotates in a driven manner to convey the paper between them, and a roller that swings about the roller axis of the main roller. a moving swing arm, supported by the swing arm, pressed against the main roller and driven to rotate;
a second sub-roller that transports the paper therebetween; and a second sub-roller that guides the paper along the outer periphery of the main roller from between the main roller and the first sub-roller to between the main roller and the second sub-roller. A paper curl correction mechanism for a recording device, comprising a guide plate for correcting paper curl. 2. A paper guide that is swingable about a fulcrum and guides the paper sent out between the main roller and the second sub-roller; the paper guide and the swing arm are connected; A paper curl correction mechanism for a recording apparatus according to claim 1, further comprising a link that moves the paper guide in conjunction with a roller.