JPH07277555A - Sheet carrying device - Google Patents

Abstract

PURPOSE:To correct the skew of a sheet body by simple structure in a sheet carrying device comprising a drive roller and a driven roller pressed to be contacted with each other. CONSTITUTION:A drive roller 13 is formed into a roller, the diameter of the axial center of which is different from the diameter of both ends, and a carrying direction correcting mechanism 29 is formed to support this drive roller 13 at the specified position movably in the axial direction, and the drive roller 13 is moved in the axial direction to vary the carrying force working to a sheet body 8 in its width direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device used for a sheet conveying mechanism of a printer device.

[0002]

2. Description of the Related Art In a paper transport mechanism of a printer device,
The separating and feeding mechanism separates and feeds a large number of sheet bodies such as printing sheets stored in a paper feed cassette one by one to a sheet conveying path, and the sheet bodies fed to the sheet conveying path. The sheet conveying device sequentially conveys the sheets. Then, by temporarily stopping the sheet body sequentially conveyed by the sheet conveying mechanism by the registration roller and releasing the sheet body at an appropriate timing by the registration roller,
The sheet body whose conveyance has been restarted is used for image printing or the like.

Here, the sheet conveying apparatus such as the above-mentioned printer has a structure in which a driving roller and a driven roller are generally in pressure contact with each other through a sheet conveying path along which sheets are sequentially conveyed. The roller is rotationally driven by a driving source connected thereto, and the driven roller is freely driven to rotate. Therefore, the rotatable driven roller presses the sheet body against the drive roller, and the drive roller applies a conveying force to the sheet body.

[0004]

The sheet conveying apparatus as described above sequentially conveys the sheet located in the sheet conveying path by the driving roller which is rotationally driven and the driven roller which is driven to rotate.

Here, in such a sheet conveying device,
Skew may occur in the conveyed sheet body due to a component error or the like, which may cause a jam or an image defect.

[0006]

The invention according to claim 1 is
A drive roller that is connected to a drive source and is driven to rotate is provided.
In a sheet conveying device in which a driven roller that freely rotates is provided, and the drive roller and the driven roller are brought into pressure contact with each other via a sheet conveying path through which a sheet body is sequentially conveyed, a diameter at the center and both sides in the axial direction The drive roller is formed in different shapes, and a transport correction mechanism is formed to movably support the drive roller in the axial direction and hold it at a predetermined position.

According to a second aspect of the present invention, in the first aspect of the present invention, the drive roller is formed by a plurality of narrow roller bodies that are continuously provided in the axial direction and are integrally driven to rotate and have different diameters. .

According to a third aspect of the present invention, in the first or second aspect of the present invention, the driven roller is formed by a pair of narrow roller members that are separately driven in the axial direction and are driven to rotate individually.

According to a fourth aspect of the present invention, in the first, second or third aspect of the invention, there is provided skew detecting means for detecting a skewed state of the sheet conveyed by the driving roller and the driven roller, and the skew detection is performed. Mechanism control means for driving and controlling the conveyance correction mechanism in accordance with the detection result of the means is provided.

According to a fifth aspect of the invention, in the first, second or third aspect of the invention, there is provided a roller contact / separation mechanism that supports the drive roller and the driven roller in a freely contactable / separable manner and holds them at a predetermined position.

According to a sixth aspect of the present invention, in the first, second or third aspect of the present invention, a roller contact / separation mechanism is provided for supporting the drive roller and the driven roller in a contactable / separable manner and holding the roller at a predetermined position. Skew detecting means for detecting the skew state of the sheet conveyed by the roller and the driven roller is provided, and mechanism control means for driving and controlling the conveyance correcting mechanism in accordance with the detection result of the skew detecting means is provided. A contact / separation interlocking device is provided which separates the drive roller and the driven roller from each other by the roller contact / separation mechanism when the means drives and controls the conveyance correction mechanism.

[0012]

According to the first aspect of the present invention, the conveyance correcting mechanism movably supports the drive rollers having different diameters at the center and both sides in the axial direction and holds them at a predetermined position. The transport force acting on the body is changed in the axial direction of the drive roller.

According to a second aspect of the present invention, a plurality of narrow roller bodies, which are continuously arranged in the axial direction and have different diameters, rotate integrally, so that the drive roller having an extremely simple structure skews the sheet body. Is corrected stepwise by a preset degree.

According to the third aspect of the present invention, the pair of narrow roller bodies that are separated from each other in the axial direction are driven to rotate individually, so that the driven roller has a different transport amount in the axial direction. Sufficiently press-contact the sheet body.

According to a fourth aspect of the invention, when the skew detecting means detects the skewed state of the sheet conveyed by the driving roller and the driven roller, the mechanism controlling means drives the conveyance correcting mechanism in response to the detection result. By controlling, the skew of the sheet body is automatically corrected.

According to a fifth aspect of the present invention, the roller contact / separation mechanism supports the drive roller and the driven roller so that they can be contacted and separated from each other and holds them at a predetermined position, so that the driven roller can be axially centered without rubbing. Move smoothly in the direction.

According to a sixth aspect of the invention, when the skew detecting means detects the skewed state of the sheet conveyed by the driving roller and the driven roller, the contact / separation interlocking means uses the roller contact / separation mechanism to connect the driving roller and the driven roller. And the mechanism control means drives and controls the conveyance correcting mechanism in this state, so that the drive roller is smoothly moved in the axial direction when the skew of the sheet body is automatically corrected.

[0018]

An embodiment of the present invention will be described below with reference to the drawings. In addition, in this embodiment, the front-back direction is defined with the conveyance direction of the sheet body as the front, but the directions such as the front-back direction and the up-down direction described here are defined for convenience of simplification of the description. It does not limit the actual installation or use direction of the device.

First, as shown in FIG. 2, the sheet conveying apparatus 1 illustrated in the present embodiment is a part of the sheet conveying mechanism 3 of the laser printer 2, and the sheet conveying mechanism 3 includes the sheet conveying mechanism 3. A sheet conveying path 7 that communicates from a sheet feeding cassette 5 arranged at the bottom of the apparatus body 4 to a sheet discharging section 6 on the upper surface of the apparatus body 4 is formed. The laser printer 2 includes a separating / feeding mechanism 9 that separates and feeds a large number of sheet bodies 8 such as printing sheets stored in the paper feed cassette 5 one by one, and the separated and fed sheet bodies 8 And a registration roller 1 for temporarily stopping and sequentially opening the sheet body 8 sequentially conveyed.
0, an electrophotographic image transfer mechanism 11 that transfers a toner image to the sequentially conveyed sheet body 8, and a fixing device 12 that fixes the toner image of the sequentially conveyed sheet body 8 to the sheet conveyance path 7 The structure is arranged in order.

The sheet conveying apparatus 1 of this embodiment used in the laser printer 2 having the above-mentioned structure is
As illustrated in FIG. 1, the driving roller 13 and the driven roller 14 are in pressure contact with each other via the sheet conveying path 7. The driven roller 14 is formed by a pair of narrow roller bodies 15 and 16 which are separated from each other in the axial direction corresponding to the lateral width of the sheet body 8.
16 are supported by driven shafts 17 so as to rotate individually.

On the other hand, the drive roller 13 is formed by four narrow roller bodies 18 to 21 having different diameters, and these roller bodies 18 to 21 are composed of two central roller bodies 19, 21. 20 has a large diameter and two roller bodies 18, 2 on both sides
1 has a small diameter. These roller bodies 18 to 21 are connected to and fixed to a drive shaft 22 in the axial direction, and the drive shaft 22 is a drive source for a drive motor 2 by a gear train 23.
4, the roller bodies 18 to 21 of the drive roller 13 are integrally driven to rotate.

The drive roller 13 is movably supported together with the drive shaft 22 in the axial direction, and a guide member 25 is provided at the end of the drive shaft 22 opposite to the gear train 23. It is mounted so as to be relatively rotatable and immovable in the axial direction. A screw shaft 27 is screwed into a screw hole 26 formed in the guide member 25. By connecting the screw shaft 27 to a stepping motor 28, the drive roller 13 can be moved in the axial direction. A transport correction mechanism 29 is formed to support and hold it at a predetermined position.

More specifically, this conveyance correction mechanism 29
Is a pair of the roller bodies 15, 1 of the driven roller 14.
6, the left two roller bodies 18, 19 of the drive roller 13 are in contact with each other, and the central two roller bodies 19, 20 are, as illustrated in FIG. 3A. And the position where the two roller bodies 20 and 21 on the right side contact, as shown in FIG. 2B, selectively connects the drive shaft 22 to one position. It is supposed to be placed. Therefore, three final gears 30 are attached to the end of the drive shaft 22 corresponding to the above-mentioned three positions, and one of the final gears 30 is engaged with the idler gear 31. It has become.

Further, in the sheet conveying apparatus 1, the driven shaft 17 is supported so as to be capable of coming into contact with and separated from the drive shaft 22 and is biased in the approaching direction by a spring (not shown) or the like. At least one end of the shaft 17 is connected to the solenoid 33 via the rotation lever 32, so that the driven roller 14 and the drive roller 13 are supported so as to be separable from each other and held at a predetermined position. A separating mechanism 34 is formed.

In the sheet conveying apparatus 1, the skew state of the sheet body 8 conveyed by the driving roller 13 and the driven roller 14 is determined by, for example, a photo sensor (not shown) arranged in the sheet conveying path 7. When the skew detection means consisting of (1) is detected, the mechanism control means drives and controls the conveyance correction mechanism 29 in accordance with the detection result. The contact / separation interlocking means separates the drive roller 13 and the driven roller 14 by the roller contact / separation mechanism 34.

In the laser printer 2 having such a structure, the separating / feeding mechanism 9 separates and feeds a large number of sheets 8 housed in the sheet feeding cassette 5 to the sheet conveying path 7 one by one, and separates the sheets. The sheet conveying device 1 sequentially conveys the fed sheet body 8 through the sheet conveying path 7. Then, after the registration rollers 10 temporarily stop the sequentially conveyed sheet body 8 and release the sheet body 8 at an appropriate timing, the image transfer mechanism 11 transfers the toner image to the sheet body 8 where the conveyance is resumed by the electrophotographic method. To do. Therefore, the toner image on the sheet body 8 is fixed by the fixing device 12, and then the sheet body 8 is carried out to the paper discharge section 6, whereby the image printing by the laser printer 2 is completed.

Then, as described above, the sheet conveying device 1 for sequentially conveying the sheet body 8 includes the driven roller 14 which is rotatable.
The sheet body 8 is brought into pressure contact with the drive roller 13, and the drive force is applied to the sheet body 8 by the drive roller 13 to sequentially convey the sheet body 8 located in the sheet conveyance path 7. At this time, as illustrated in FIG.
Normally, the roller bodies 15 and 16 of the driven roller 14 are in contact with the roller bodies 19 and 20 of the same diameter at the center of the drive roller 13, and these roller bodies 19 and 20 of the same diameter are conveyed by the rotation amount. Therefore, the sheet body 8 is conveyed without skew.

Here, even in this case, skew may occur in the conveyed sheet body 8 due to a component error or the like, but in this sheet conveying apparatus 1, the skew state is detected by the skew detecting means. The mechanism control means drives and controls the conveyance correction mechanism 29 to correct the skew of the sheet body 8. More specifically, when the sheet body 8 is skewed to the left, a contact / separation interlocking means separates the drive roller 13 and the driven roller 14 by the roller contact / separation mechanism 34, and the mechanism control is performed in this state. Means controls the conveyance correction mechanism 29 to drive the roller bodies 20, 21 on the right side of the drive roller 13 to the roller bodies 15, 1 of the driven roller 14.
6, the contact / separation interlocking means presses the driving roller 13 and the driven roller 14 by the roller contact / separation mechanism 34.

By doing so, as shown in FIG. 3B, the roller bodies 20, 2 on the right side of the drive roller 13 are formed.
1 is located in the sheet conveying path 7, the driving roller 13 is a roller body 21 on the right side of the central roller body 20.
Is small, the conveyance amount acting on the sheet body 8 is decreased from the left side to the right side, and the skew of the sheet body 8 deflected to the left side is corrected. Similarly, when a skew occurs in which the sheet body 8 is deflected to the right, the mechanism control unit controls the conveyance correction mechanism 29 to drive the roller bodies 18 and 19 on the left side of the drive roller 13 to the driven roller 14. By pressing the rollers 15 and 16 into contact with each other, the conveyance amount acting on the sheet body 8 is reduced leftward to correct the skew.

Further, in the sheet conveying apparatus 1 of this embodiment,
As an embodiment of the invention as set forth in claim 2, the drive roller 13 is formed by a plurality of narrow roller bodies 18 to 21 which are continuously arranged in the axial direction and are integrally driven to rotate, and have different diameters. By holding 13 in the axial direction stepwise,
The sheet conveying apparatus 1 is configured to correct the skew of the sheet body 8 stepwise by a preset degree. Further, the drive roller 13 having the above-described structure can be formed by simply connecting the existing roller bodies 18 to 21 having different diameters, so that the structure is extremely simple and the productivity of the sheet conveying apparatus 1 is improved. Can contribute. However, the present invention is not limited to the above-described embodiment, and for example, a single elongated driving roller (not shown) having a large diameter at the central portion and small diameters at both ends is formed, and such a driving roller is used as a shaft. It is also possible to adjust the skew of the sheet body steplessly by moving it steplessly in the axial direction.

Further, in the sheet conveying apparatus 1 of the present embodiment, as an embodiment of the invention described in claim 3, a pair of narrow roller bodies 1 which are separated from each other in the axial direction and are independently driven and rotated.
By forming the driven roller 14 with the rollers 5 and 16, the sheet body 8 is attached to the drive roller 13 in a state where the transport amount is different in the axial direction.
It is designed to make good pressure contact. However, the present invention is not limited to the above-described embodiment. For example, a single elongated driven roller (not shown) in which the sheet body appropriately slips, or a flexible roller which is diametrically compressed by pressure contact with a driving roller. Even with a driven roller or the like, the sheet body 8 can be satisfactorily pressed against the drive roller 13 in which the left and right conveyance amounts are different.

Further, in the sheet conveying apparatus 1 of this embodiment,
As an embodiment of the invention described in claim 5, the drive roller 13
The roller contact / separation mechanism 34 supports the driven roller 14 and the driven roller 14 in a freely movable manner and holds the driven roller 14 at a predetermined position so that the drive roller 13 can be smoothly moved in the axial direction.
However, the present invention is not limited to the above-described embodiment, and it is also conceivable to move the driving roller 13 in the axial direction while rotating the driving roller 13, for example. In the sheet conveying apparatus 1 of the present embodiment, the driving roller 13 moves only in the axial direction and the driven roller 14 moves in the contacting / separating direction, which simplifies the structure and contributes to improvement in productivity. However, it is also possible for the drive roller to move in the axial direction and the contact / separation direction without moving the driven roller, or for both the driven roller and the drive roller to move in the contact / separation direction. Is.

Further, in the sheet conveying apparatus 1 of this embodiment,
As an embodiment of the invention of claim 4, the skew detecting means detects the skew state of the sheet body 8 conveyed by the driving roller 13 and the driven roller 14, and the mechanism controlling means corresponds to the detection result. By driving and controlling the conveyance correction mechanism 29, the skew of the sheet body 8 is automatically corrected. However, the present invention is not limited to the above-described embodiment, and, for example, a user who recognizes the skewed state of the sheet body 8 may drive the conveyance correction mechanism 29 by manual operation.

Similarly, in the sheet conveying apparatus 1 of the present embodiment, as an embodiment of the invention according to claim 6, when the mechanism control means drives and controls the conveyance correcting mechanism 29, the contact / separation interlocking means is the roller contact / separation mechanism. Drive roller 13 and driven roller 1 at 34
When the skew of the sheet body 8 is automatically corrected, the drive roller 13 can be smoothly moved in the axial direction by separating the drive roller 13 from the drive roller 4. However, the present invention is not limited to the above-described embodiment. For example, a user who recognizes the skewed state of the sheet body 8 may manually drive the roller contact / separation mechanism 34 and the conveyance correction mechanism 29. Is also possible.

[0035]

According to the first aspect of the present invention, a drive roller which is connected to a drive source and is rotationally driven is provided, a driven roller which is freely driven and rotated is provided, and a sheet conveying path through which sheet bodies are sequentially conveyed is provided. In a sheet conveying device in which the drive roller and the driven roller are brought into pressure contact with each other, the drive roller is formed in a shape having different diameters at the center and both sides in the axial direction, and the drive roller is movable in the axial direction. By forming a transport correction mechanism that is supported on and held at a predetermined position,
By moving the drive roller in the axial direction with this conveyance correction mechanism, the conveying force acting on the sheet body can be changed in the axial direction of the drive roller, so that the skew of the sheet body can be corrected. It has the effect of.

According to a second aspect of the present invention, in the first aspect of the present invention, the drive roller is formed by a plurality of narrow roller bodies which are continuously provided in the axial direction and are integrally rotationally driven, and have different diameters. Thus, the skew of the sheet body can be corrected stepwise by a preset degree, and the drive roller having such a structure can be formed by the existing roller body, which can contribute to the improvement of productivity. It has the effect of.

According to a third aspect of the present invention, in the first or second aspect of the invention, the driven roller is formed of a pair of narrow roller members that are driven to rotate separately from each other in the axial direction. This has an effect such that the sheet body can be satisfactorily pressed against the drive roller in a state where the transport amount differs in the axial direction.

According to a fourth aspect of the present invention, in the first, second or third aspect of the invention, there is provided skew detecting means for detecting a skewed state of the sheet conveyed by the driving roller and the driven roller, and the skew detection is performed. By providing the mechanism control means for driving and controlling the conveyance correction mechanism in accordance with the detection result of the means, it is possible to automatically correct the skew of the sheet body.

According to a fifth aspect of the present invention, in the first, second or third aspect of the present invention, a roller contact / separation mechanism is provided for supporting the drive roller and the driven roller in a freely contactable / separable manner and holding the roller at a predetermined position. Thus, when the drive roller is moved in the axial direction, it is possible to prevent the driven roller from being scratched.

According to a sixth aspect of the invention, in the first, second or third aspect of the invention, a roller contacting / separating mechanism for supporting the driving roller and the driven roller in a contactable / separable manner and holding the roller at a predetermined position is provided, Skew detecting means for detecting the skew state of the sheet conveyed by the roller and the driven roller is provided, and mechanism control means for driving and controlling the conveyance correcting mechanism in accordance with the detection result of the skew detecting means is provided. When the skew of the sheet body is automatically corrected by providing the contact / separation interlocking means for separating the drive roller and the driven roller from each other by the roller contact / separation mechanism when the means controls the conveyance correction mechanism. In addition, it is possible to smoothly perform the movement of the drive roller in the axial direction.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating an example of a sheet conveying apparatus according to the present invention.

FIG. 2 is a vertical cross-sectional side view illustrating the internal structure of a laser printer including a sheet conveying device as a part.

FIG. 3 illustrates a relationship between a driving roller and a driven roller,
FIG. 6A is a front view illustrating a state where skew correction is not performed, and FIG. 6B is a front view illustrating a state where skew correction is performed.

[Explanation of symbols]

 1 Sheet Supply Device 7 Sheet Conveying Path 8 Sheet Body 13 Drive Roller 14 Driven Rollers 15, 16, 18-21 Roller Body 24 Drive Source 29 Conveyance Correction Mechanism 34 Roller Contact / Separation Mechanism

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Inoue 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (6)

[Claims] 1. A drive roller which is connected to a drive source and is driven to rotate, and a driven roller which is freely driven to rotate are provided.
In a sheet conveying device in which the driving roller and the driven roller are in pressure contact with each other via a sheet conveying path along which the sheet bodies are sequentially conveyed, the driving roller is formed in a shape in which the diameter is different between the center and both sides in the axial direction. Then, the sheet conveying apparatus is characterized in that a conveyance correcting mechanism is formed which supports the driving roller so as to be movable in the axial direction and holds the driving roller at a predetermined position. 2. The sheet conveying apparatus according to claim 1, wherein the driving roller is formed by a plurality of narrow roller bodies that are continuously provided in the axial direction and are integrally driven to rotate and have different diameters. 3. The sheet conveying apparatus according to claim 1, wherein the driven roller is formed by a pair of narrow roller bodies that are driven to rotate separately from each other in the axial direction. 4. A mechanism control means for providing a skew detecting means for detecting a skew state of a sheet conveyed by a driving roller and a driven roller, and drivingly controlling a conveyance correcting mechanism in accordance with a detection result of the skew detecting means. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is provided with. 5. The sheet conveying apparatus according to claim 1, further comprising a roller contact / separation mechanism that supports the drive roller and the driven roller so that they can come into contact with and separate from each other and holds them at a predetermined position. 6. A skew for detecting a skewed state of a sheet body conveyed by the drive roller and the driven roller, the roller contacting / separating mechanism supporting the drive roller and the driven roller in a contactable / separable manner and holding them at a predetermined position. A detection means is provided, and a mechanism control means is provided for driving and controlling the conveyance correction mechanism in accordance with the detection result of the skew detection means. When the mechanism control means drives and controls the conveyance correction mechanism, the roller contact / separation mechanism is used. 4. The sheet conveying apparatus according to claim 1, further comprising contact / separation interlocking means for separating the drive roller and the driven roller from each other.