JP2010111486A - Recording medium conveying device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording medium conveying device capable of preventing a recording medium from being corrugated. <P>SOLUTION: In the recording medium conveying device, a guide 82 includes a guide face 84 located at a position opposing the recording medium to be conveyed and guide projections 86a-86l, 88a, 88b formed on the guide face 84. The guide projections 86a-86l are formed to have substantially the same heights from the guide face 84. The height of the guide projection 86 is set to enable the recording medium to be properly conveyed between a conveyance roll 35 and a conveyance roll 33. The guide projection 88a is formed between the guide projection 86e and the guide projection 86f, and the guide projection 88b is formed between the guide projection 86i and the guide projection 86j. The height of the guide projection 88a from the guide face 84 and the height of the guide projection 88b from the guide face 84 are set to be higher than the height of the guide projection 86 from the guide face 84. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a recording medium conveying apparatus and an image forming apparatus.

  In Patent Document 1, guide protrusions having different heights are formed on a printing receiving member at two or more different intervals, a low guide protrusion is sandwiched between two high guide protrusions, and an interval between high guide protrusions is equal. Disclosed is an image forming apparatus in which a portion that is not spaced is at an end in the paper width direction.

JP 2006-143477 A

  An object of the present invention is to provide a recording medium transport apparatus that can reduce the occurrence of undulations in a recording medium.

  In order to achieve the above object, the present invention according to claim 1 is directed to a first conveyance unit that conveys a recording medium, and a guide that is provided downstream of the first conveyance unit in the recording medium conveyance direction and guides the recording medium. A plurality of guide projections are provided on a first surface of the guide portion facing the recording medium to be conveyed, and the first guide projections of the plurality of guide projections The height from the first surface is a recording medium conveying device formed so as to be higher than the height from the first surface of the second guide protrusion provided on both sides of the first guide protrusion.

  The present invention according to claim 2 further includes a second transport unit that is provided downstream of the guide portion in the recording medium transport direction, and transports the recording medium, and the first guide protrusion is the second transport member. The height of the first guide protrusion from the first surface is not opposite to the means, and the height of the third guide protrusion provided at a position opposite to the second transport means is The recording medium carrying device according to claim 1, wherein the recording medium carrying device is formed higher than a height from the first surface.

  According to a third aspect of the present invention, there is provided the recording medium conveying apparatus according to the first or second aspect, wherein the first conveying means is configured to roll and convey a plurality of overlapping recording media one by one. .

  According to a fourth aspect of the present invention, the second transport unit is divided into a plurality of portions, and the first guide protrusion is located downstream of the first transport unit in the recording medium transport direction. 4. The recording medium conveying apparatus according to claim 2, wherein the recording medium conveying device is provided in the vicinity of both ends of the portion of the second conveying means at a position.

  According to a fifth aspect of the present invention, when the height of the first guide protrusion from the first surface is viewed from the upstream side in the recording medium conveyance direction, the second conveyance from the first surface. 5. The recording medium conveying apparatus according to claim 2, wherein the recording medium conveying apparatus is formed lower than the distance to the contact surface of the means with the recording medium.

  According to a sixth aspect of the present invention, there is provided an image forming apparatus having the recording medium conveying device according to any one of the first to fifth aspects.

  According to the first aspect of the present invention, it is possible to provide a recording medium transport apparatus that can reduce the occurrence of undulations in the recording medium as compared with the case where the configuration of the present invention is not provided.

  According to the second aspect of the present invention, in addition to the effect of the present invention according to the first aspect, it is possible to reduce the occurrence of waviness of the recording medium by the second conveying means.

  According to the third aspect of the present invention, it is possible to reduce the occurrence of undulations in the recording medium when the first conveying means is configured to roll up a plurality of overlapping recording media one by one.

  According to the fourth aspect of the present invention, it is possible to reduce the occurrence of undulation of the recording medium that occurs in the vicinity of both ends of the portion of the second conveying unit that is downstream of the first conveying unit in the recording medium conveying direction.

  According to the fifth aspect of the present invention, the first guide protrusion does not disturb the conveyance of the recording medium.

  According to the sixth aspect of the present invention, it is possible to provide an image forming apparatus that exhibits the effect of the recording medium conveying device according to any one of the first to fifth aspects.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an outline of an image forming apparatus 10 according to an embodiment of the present invention. The image forming apparatus 10 includes an image forming apparatus main body 12, an image forming unit 14 is mounted in the image forming apparatus main body 12, and a discharge unit 16 described later is provided on the upper part of the image forming apparatus main body 12. For example, a paper feed unit 18 and a manual paper feed unit 19 are disposed at the lower part of the image forming apparatus main body 12.
Note that each of the paper feeding unit 18 and the manual paper feeding unit 19 has a function as a recording medium conveyance device that conveys a recording medium such as paper and an OHP recording medium.

The paper feed unit 18 includes a paper feed unit main body 20 and a paper feed cassette 22 that can store a plurality of recording media.
A pickup roll 24 as a conveying member is disposed in the upper part near the rear end of the paper feed cassette 22, and a separating roll 26 and a supply roll 28 are disposed behind the pickup roll 24.
The supply roll 28 is driven by a drive unit (not shown) and conveys the recording medium toward a registration roll 38 to be described later.
The separating roll 26 is in pressure contact with the supply roll 28 and is configured to rotate according to the rotation of the supply roll 28, and feeds the recording medium one by one toward a later-described registration roll 38 together with the supply roll 28. For example, when a plurality of recording media are sandwiched between the supply roll 28 and the separating roll 26, the separating roll 26 causes a slip between the stacked recording media, and the recording in which the supply roll 28 is not in contact is performed. The medium is prevented from being conveyed, the recording medium is rolled, and only the uppermost recording medium is sent to a registration roll 38 to be described later.

The manual paper feed unit 19 includes a manual paper feed unit main body 30, a recording medium storage unit 31 that can store a plurality of recording media, a separating roll 32, and a transport roll 33, which will be described later. A paper feed roll 34 as a transport roll is disposed in the upper part on the back side of the manual paper feed unit 19, and a transport roll 35 is disposed on the image forming apparatus main body 12 side behind the paper feed roll 34.
By opening a front cover 68 that opens and closes a part of the front side (right side in FIG. 1) of the image forming apparatus 10 in the direction of arrow A, the recording medium accommodation unit 31 can be accessed.

The paper feed roll 34 is provided on the image forming apparatus main body 12 side and is driven by a drive unit (not shown) to convey the recording medium stored in the recording medium storage unit 31 toward the image forming unit 14.
The separating roll 32 is in pressure contact with the paper feed roll 34 and is rotatable in accordance with the rotation of the paper feed roll 34. In cooperation with the paper feed roll 34, the recording media are conveyed one by one in the recording medium conveyance direction. It acts so as to send it out between the transport roll 35 and the transport roll 33 on the downstream side. For example, when a plurality of recording media are sandwiched between the paper feed roll 34 and the paper roll 32, the paper roll 32 causes slippage between the stacked recording media so that the paper feed roll 34 is in contact. An unrecorded recording medium is prevented from being conveyed, the recording medium is rolled, and only the uppermost recording medium is sent out between the conveying roll 35 and the conveying roll 33.

The conveyance roll 35 is provided on the image forming apparatus main body 12 side, and is driven by a driving unit (not shown) so as to convey a recording medium that is rolled by the separation roll 32 and the sheet supply roll 34 toward a registration roll 38 to be described later. Rotate to.
The conveyance roll 33 is pressed against the conveyance roll 35 and is rotatable in accordance with the rotation of the conveyance roll 35, and rotates so as to send the recording medium toward the registration roll 38 together with the conveyance roll 35.

The main transport path 36 is a recording medium path from the supply roll 28 to the discharge port 37, and the main transport path 36 is on the back side (the left side surface in FIG. 1) of the image forming apparatus main body 12. To a fixing device 39 to be described later. A transfer device 42 and an image holding body 44, which will be described later, are arranged on the upstream side of the fixing device 39 in the main transport path 36, and a registration roll 38 is arranged on the upstream side of the transfer device 42 and the image holding body 44.
The registration roll 38 temporarily stops the recording medium supplied to the main conveyance path 36 and conveys the recording medium between the transfer device 42 and the image carrier 44 at a predetermined timing after aligning the leading end position. .
Further, a discharge roll 40 is disposed in the vicinity of the discharge port 37 of the main conveyance path 36.

  Therefore, the recording medium sent out from the paper feeding cassette 22 of the paper feeding unit 18 by the pickup roll 24 is fed by the cooperation of the separating roll 26 and the supply roll 28 and only the uppermost recording medium is guided to the main transport path 36. The developer image is temporarily stopped by the resist roll 38, and the developer image is transferred between a transfer device 42 and an image holding member 44, which will be described later, and the transferred developer image is fixed by the fixing device 39. The paper is discharged from the discharge port 37 to the discharge unit 16 by the discharge roll 40.

  In addition, the recording medium sent out from the recording medium container 31 of the manual sheet feeding unit 19 by the sheet feeding roll 34 is transported only by the recording medium positioned at the highest level by the cooperation of the separating roll 32 and the sheet feeding roll 34. Guided between the roll 35 and the transport roll 33, temporarily stopped by the registration roll 38, and a developer image is transferred between a transfer device 42 and an image holding body 44, which will be described later, at a timing. Similarly to the recording medium sent out from the unit 18, the developer image is fixed by the fixing device 39 and discharged from the discharge port 37 to the discharge unit 16 by the discharge roll 40.

However, in the case of duplex printing, it is returned to the reverse path. That is, the front of the discharge roll 40 in the main transport path 36 is divided into two forks, and a switching device 46 is provided at the divided part, and a reverse path 48 is formed to return from the divided part to the registration roll 38. .
The reversing path 48 is provided with transport rolls 50a to 50c. In the case of double-sided printing, the switching device 46 is switched to the side that opens the reversing path 48, and the discharge roll 40 is in front of the rear end of the recording medium. At that time, the discharge roll 40 is reversed, the recording medium is guided to the reverse path 48, and is discharged from the discharge port 37 to the discharge unit 16 through the registration roll 38, the transfer device 42, the image holding body 44 and the fixing device 39. It is.

The image forming unit 14 is of, for example, an electrophotographic system, and is charged by an image holding member 44 such as a photosensitive member, a charging device 56 including a charging roll for uniformly charging the image holding member 44, and the charging device 56. An optical writing device 58 for writing a latent image on the image holding member 44 by light, a developing device 60 for visualizing the latent image of the image holding member 44 formed by the optical writing device 58 with a developer, and the developing device. For example, a transfer device 42 such as a transfer roll that transfers the developer image by the recording medium 60 to the recording medium, a cleaning device 62 such as a blade that cleans the developer remaining on the image carrier 44, and the recording transferred by the transfer device 42. And a fixing device 39 for fixing the developer image on the medium to the recording medium.
The optical writing device 58 is composed of, for example, a scanning type laser exposure device, and is disposed on the front side of the image forming apparatus main body 12 so as to be substantially parallel to the upper surface of the manual sheet feeding unit 19 described above. 44 is exposed.

  In the process cartridge 64, the image carrier 44, the charging device 56, the developing device 60, and the cleaning device 62 are integrated, and these can be replaced as a unit. The process cartridge 64 can be removed from the image forming apparatus main body 12 by opening the discharge unit 16.

Next, the manual sheet feeding unit 19 and its periphery will be described in detail.
FIG. 2 shows details of the manual sheet feeding unit 19.
The manual paper feed unit 19 includes a manual paper feed unit main body 30, a recording medium storage unit 31, and a lower transport unit 78.
In the recording medium accommodating portion 31, two conveyance guides 70 are provided substantially in parallel to the recording medium conveyance direction for reliably guiding the recording medium in the conveyance direction.
The bottom surface 29 of the manual sheet feeding unit 19 is configured to move up and down by being transmitted from the image forming apparatus main body 12 side. When the recording medium is not conveyed toward the image forming unit 14, the recording medium is moved downward around a point (not shown) on the front side of the manual sheet feeding unit main body 30 so as to easily accommodate the recording medium. Further, when the recording medium is conveyed toward the image forming unit 14, the recording medium located at the uppermost position moves upward so as to come into contact with the paper feed roll 34.

The lower transport unit 78 is opposed to an upper transport unit 80 provided on the image forming apparatus main body 12 side.
The lower transport unit 78 has a separating roll 32 and a transport roll 33, and the upper transport unit 80 has a paper feed roll 34 and a transport roll 35.
Further, a guide unit 82 for guiding the recording medium is provided between the paper feed roll 34 and the transport roll 35 of the upper transport unit 80. The guide portion 82 functions as an upper recording medium conveyance path.

In FIG. 3, the details of the upper transport unit 80 are shown. FIG. 3 is a view of the upper transport unit 80 as viewed from below in FIG.
Further, FIG. 4 shows a cross-sectional view of the guide portion 82 viewed from the upstream side in the recording medium conveyance direction. FIG. 4 is a view of the cross section B shown in FIG.
The guide unit 82 includes a guide surface 84 at a position facing the recording medium to be conveyed, and guide protrusions 86a to 86l, 88a, 88b provided on the guide surface 84.
The guide protrusion 86 and the guide protrusion 88 are formed substantially parallel to the recording medium conveyance direction, and guide the recording medium between the conveyance roll 35 and the conveyance roll 33.
The guide protrusions 86a to 86l are formed so that the height from the guide surface 84 is substantially the same. The height of the guide protrusion 86 is such that the recording medium is appropriately transported between the transport roll 35 and the transport roll 33. That is, the distance between the guide protrusion 86 and the transport roll 33 that is in pressure contact with the transport roll 35 is an interval that does not interfere with the transport of the recording medium.

The guide protrusion 88a is formed between the guide protrusion 86e and the guide protrusion 86f, and the guide protrusion 88b is formed between the guide protrusion 86i and the guide protrusion 86j.
The height H1 of the guide protrusion 88a from the guide surface 84 is higher than the height H2 of the guide protrusion 86e from the guide surface 84 and the height H3 of the guide protrusion 86f from the guide surface 84 (that is, H1> H2, H1>). H3).
Similarly, the height H4 of the guide projection 88b from the guide surface 84 is higher than the height H5 of the guide projection 86i from the guide surface 84 and the height H6 of the guide projection 86j from the guide surface 84 (that is, H4> H5). , H4> H6).

The transport roll 35 is divided into a plurality of parts on the rotary shaft 90, and the transport roll 35a is located downstream of the paper feed roll 34 in the recording medium transport direction, and the transport rolls 35b and 35c are provided at both ends thereof. It consists of. The guide protrusions 88a and 88b are provided in the vicinity of both ends of the transport roll 35a.
Similarly to the transport roll 35, the transport roll 33 is also divided and provided, and the transport roll 33a is in pressure contact with the transport roll 35a as shown in FIG.
The height H1 of the guide protrusion 88a and the height H4 of the guide protrusion 88b are higher than the heights H7 and H8 from the guide surface 84 of the transport roll 35a and the transport roll 33a.
Further, the height H1 of the guide projection 88a and the height H4 of the guide projection 88b are larger than the distance L from the contact surface 92 of the transport roll 35a and the transport roll 33a to the guide surface 84 so as not to disturb the transport of the recording medium. It is made low (that is, H1 <L, H4 <L).

Hereinafter, the operation of the present embodiment will be described.
FIG. 5 shows the operation of the present embodiment. FIG. 5A shows a case where the guide protrusion 88 is not provided, and FIG. 5B shows a case where the guide protrusion 88 is provided. . FIG. 5 is a view of the cross section B shown in FIG.

When the separating roll 32 and the sheet feeding roll 34 cooperate to roll a recording medium, the sheet feeding roll 34 rotates to convey the recording medium positioned at the uppermost position, whereas the separating roll 32 feeds a sheet. The roll 34 operates to prevent conveyance of the recording medium that is not in contact with the roll 34. For this reason, a load is applied to the vicinity of the center of the recording medium in contact with the separating roll 32 and the paper feed roll 34, and the recording medium may be wavy.
In addition, the recording medium to be transported may be subjected to a load at the contact portion between the transport roll 33 and the transport roll 35 located on the downstream side in the recording medium transport direction. There is sex.

Therefore, as shown in FIG. 5 (A), when the guide protrusion 88 is not provided, the gap between the guide protrusion 86e and the guide protrusion 86f near the both ends of the transport roll 33a and between the guide protrusion 86i and the guide protrusion 86j. As shown by arrows D and E, the recording medium undulates between the guide projections 86e and 86f and between the guide projections 86i and 86j.
When the recording medium S enters between the transport roll 33 and the transport roll 35 in this state, the recording medium is transported while the corrugated shape of the recording medium is maintained, and enters a roll that is not divided in the axial direction, such as a photosensitive drum. At times, the recording medium S may be wrinkled.

  On the other hand, as shown in FIG. 5 (B), when the guide protrusion 88 is provided, the guide protrusion 88 causes the guide protrusion 86e to be interposed between the guide protrusion 86f and the guide protrusion 86i to the guide protrusion 86j. Since the recording medium S does not enter the recording medium S, the waviness of the recording medium S is suppressed, and the occurrence of wrinkles in the recording medium S when entering the roll that is not divided in the axial direction can be suppressed.

In the present embodiment, the guide unit 82 is provided in the path for conveying the recording medium accommodated in the manual feed unit 19 to the downstream side, but it may be provided anywhere near the roll for conveying the recording medium. Good.
In the present embodiment, two guide protrusions 88 are provided, but one guide protrusion 88 may be provided, or three or more guide protrusions 88 may be provided.

1 is a side view illustrating an outline of an image forming apparatus according to an embodiment of the present invention. 3 is a cross-sectional view illustrating an outline of a manual sheet feeding unit. FIG. It is a perspective view which shows the detail of an upper conveyance unit. FIG. 6 is a cross-sectional view of a guide portion and guide protrusions as viewed from the upstream side in the recording medium conveyance direction. It is a figure which shows the effect | action of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 14 Image forming part 18 Paper feed unit 19 Manual paper feed unit 30 Manual paper feed unit main body 31 Recording medium accommodating part 32 A separating roll 33 A conveyance roll 34 A supply roll 35 A conveyance roll 78 A lower conveyance unit 80 An upper conveyance unit 82 Guide Part 84 Guide surface 86 Guide protrusion 88 Guide protrusion

Claims (6)

First conveying means for conveying a recording medium;
A guide unit that guides the recording medium, and is provided downstream of the first conveying unit in the recording medium conveyance direction,
A plurality of guide protrusions are provided on the first surface of the guide portion facing the recording medium to be conveyed,
The height of the first guide protrusion from the first surface of the plurality of guide protrusions is from the first surface of the second guide protrusion provided on both sides of the first guide protrusion. A recording medium transport device formed higher than the height. Provided further downstream of the guide unit in the recording medium conveying direction, and further comprising a second conveying means for conveying the recording medium;
The first guide protrusion is provided at a position that does not face the second conveying means,
The height of the first guide protrusion from the first surface is higher than the height of the third guide protrusion provided at a position facing the second conveying means from the first surface. The recording medium carrying device according to claim 1. The recording medium conveying apparatus according to claim 1, wherein the first conveying unit is configured to pick up and convey a plurality of overlapping recording media one by one. The second conveying means is provided divided into a plurality of parts,
4. The recording according to claim 2, wherein the first guide protrusion is provided in the vicinity of both ends of the portion of the second transport unit that is located downstream of the first transport unit in the recording medium transport direction. Medium transport device. The height of the first guide protrusion from the first surface is from the first surface to the contact surface with the recording medium of the second conveying means when viewed from the upstream side in the recording medium conveying direction. The recording medium conveyance device according to claim 2, wherein the recording medium conveyance device is formed to be lower than the distance of the recording medium.   An image forming apparatus comprising the recording medium conveyance device according to claim 1.

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