JP2002296850A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original feeding roller with which wrinkles are not caused to an original and an image forming device using it. SOLUTION: A lower roller 28 is constituted of nine lower rollers 34 juxtaposed by leaving a specified space A (for instance 10 cm) with each other in the axial direction. An upper roller 27 is constituted of five upper rollers 33 juxtaposed by leaving the specified space A with each other in the axial direction. When an original feeding device 3 is closed, the individual upper rollers 33 constituting the upper roller 27 are brought into press-contact with five lower rollers 34 constituting the lower roller 28 at the center in the axial direction. Thus, a contact width between the upper roller 27 and the original is made shorter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and the like, and more particularly, to a document conveying roller for conveying a document to a document reading section.

[0002]

2. Description of the Related Art Conventionally, there has been known an image forming apparatus capable of forming an image on a wide sheet of paper having a size equal to or larger than the size of column A (hereinafter referred to as "A1") of Japanese Industrial Standard (JIS). Some image forming apparatuses of this type transport a document along the upper surface of a housing, for example. A document feeder is arranged on the upper surface of the housing, and the document is transported between the upper surface of the housing and the document feeder,
The image is read by a scanner.

[0003] The image forming apparatus is provided with a pair of document conveying rollers including an upper roller disposed at the bottom of the document conveying device and a lower roller disposed on the upper surface of a housing opposed to the upper roller. I have. The lower roller includes, for example, nine cylindrical lower rollers, and these lower rollers are held on a rotating shaft that is driven to rotate by a drive system. The upper roller includes the same nine cylindrical upper rollers as the lower roller, and these upper rollers are rotatably held by a rotating shaft.
Each upper roller of the upper roller is pressed against the corresponding lower roller of the lower roller to form a pair.

[0004]

However, in a wide image forming apparatus capable of forming an image on a sheet of A1 size or larger, the width of the document to be applied is large. In some cases, the contact width was long, and wrinkles occurred at both ends of the document. In particular, when a thin original such as tracing paper is conveyed, wrinkles are likely to occur at both ends.

The present invention has been made in view of such a background, and has as its object to provide an image forming apparatus in which a document does not wrinkle.

[0006]

According to the first aspect of the present invention, there is provided an image forming apparatus having a document reading device capable of reading a wide document of A1 size or more. A plurality of rollers arranged in a document conveying path for conveying a document and arranged in the width direction of the document, wherein the plurality of rollers are configured to be smaller than a plurality of lower rollers and the lower roller; An image forming apparatus, comprising: a plurality of lower rollers which are pressed from above to a central roller in the width direction of a document and form a pair.

[0007] The outer shape of the image forming apparatus is partitioned by a substantially rectangular housing. A document feeder is arranged on the upper surface of the housing, and the document is fed between the upper surface of the housing and the document feeder. A scanner is arranged at the upper end of the housing so as to face the document feeder. A document is read by a scanner while the document is being conveyed between the upper surface of the housing and the document conveying device.

According to the configuration of the present invention, the central portion in the width direction of the document is transported by a pair of upper roller and lower roller, and both ends in the width direction of the document are transported only by the lower roller. Therefore, the contact width between the upper roller and the document can be shortened, so that wrinkles can be prevented from being formed at both ends of the document. It is preferable that the lower roller is composed of nine pieces and the upper roller is composed of five pieces. Preferably, the plurality of rollers are arranged at predetermined intervals (for example, 10 cm) in the width direction of the document. By these,
The generation of wrinkles in the document can be suitably prevented.

According to a second aspect of the present invention, the document reading apparatus includes a scanner for reading a document, wherein the plurality of rollers are arranged in a plurality of pairs in a document conveying direction. An image forming apparatus according to claim 1, wherein at least a roller arranged on the near side of the scanner in the document conveying direction has a configuration according to claim 1. According to this configuration, it is possible to prevent the original before being read by the scanner from wrinkling.

[0010]

Embodiments of the present invention will be specifically described below with reference to the drawings. Although a copying machine will be described as an embodiment of the present invention, the present invention is not limited to the copying machine, and can be applied to an image forming apparatus such as a printer and a facsimile. FIG. 1 is a schematic sectional view showing a configuration of a copying machine 1 according to an embodiment of the present invention. The copying machine 1 is an image forming apparatus capable of forming an image on a wide sheet such as an A0 size sheet. In FIG. 1, the right side is the front and the left side is the back.

The copying machine 1 has an outer shape defined by a housing 2 having a substantially rectangular shape, a document reading section 10 having a scanner 13 for reading a document, and a paper storage section 11 for storing paper such as roll paper. An image forming unit 14 for transferring a toner image based on an image of a document read by a scanner 13 to a sheet conveyed from a sheet storage unit 11 through a sheet conveyance path 12; and a toner transferred to the sheet. A fixing device 15 for fixing an image is provided.

The document reading section 10 is provided with two pairs of document conveying rollers 25 and 26 extending in the left-right direction in front and back. Each document transport roller pair 25, 26 is for transporting a document from the near side to the rear side, and the document transport roller pair 25 on the near side includes an upper roller 27 and a lower roller 28 arranged vertically. And the rear document transport roller 2
6 is an upper roller 29 and a lower roller 3
It consists of 0. The document reading unit 10 includes a document conveying device 3 arranged on the upper surface 2b of the housing 2. Each upper roller 2
7 and 29 are attached to the bottom of the document feeder 3, and each lower roller 25 and 26 is
It is attached to the upper end of the housing so as to face 7, 28.

On the upper surface 2 b of the housing 2, a mounting table 4 for setting a document is provided in front of the document feeder 3. The document is placed on the placing table 4 so that the front surface faces downward. The upper surface 2b of the housing 2 forms a document conveying path, and the document set on the mounting table 4 is conveyed backward through the space between the upper surface 2b of the housing 2 and the document conveying device 3. A scanner 13 extending in the left-right direction is disposed between the lower rollers 25 and 26 at the upper end of the housing 2, and a contact glass 32 is provided above the scanner 13 on the upper surface 2 b of the housing 2. (See FIG. 2). The original conveyed between the upper surface 2b of the housing 2 and the original conveying device 3 is moved through the contact glass 32 while passing over the contact glass 32.
An image can be read by a scanner 13 arranged below the image forming apparatus 2.

At the bottom of the document feeder 3, both upper rollers 2
A pressing roller 31 extending in the left-right direction is disposed between 7 and 29. The pressing roller 31 is a contact glass 32
This is for pressing a document passing above so as not to float on the surface of the contact glass 32. The image forming unit 14 is disposed at an upper portion in the housing 2 and is driven to rotate counterclockwise in FIG.
6 is provided. The photosensitive drum 16 has, on its outer peripheral surface has a photosensitive layer, after being uniformly charged by the discharge of the main charger 17, the LED print head 18 based on the image of a document read by the scanner 13 It is exposed by irradiating light. As a result, a so-called electrostatic latent image is formed on the surface of the photosensitive drum 16.

Toner is adhered to the surface of the photosensitive drum 16 on which the electrostatic latent image is formed by the developing device 19 to form a toner image. When the photosensitive drum 16 is further rotated, the transfer device 20 transfers the toner image to the sheet conveyed from the sheet storage unit 11 through the sheet conveyance path 12. The toner remaining on the surface of the photosensitive drum 16 after the transfer of the toner image is collected by the cleaning device 21. The sheet on which the toner image has been transferred is placed in a fixing device 15.
After the fixing process is performed by the fixing device 15, the sheet is discharged to the outside of the housing 2 by the discharge roller 22.

At the upper part of the back plate 2a of the housing 2, air inlets 5 for taking in air outside the housing 2 into the housing 2 are formed at both left and right ends. A duct 23 is connected to the intake port 5 at an upper rear portion inside the housing 2. In the duct 23, a fan 24 for guiding the air outside the housing 2 from the air inlet 5 into the housing 2 is provided.
Is to be led to. Accordingly, the image forming unit 14 can be cooled, and oxidation products such as ozone and NOx generated by the discharge of the main charger 15 can be dispersed in the apparatus so as not to be stuck around the photosensitive drum 16. it can.

The document feeder 3 is rotatably mounted along its rear edge, and can be opened counterclockwise from a closed state as shown in FIG. ing. As a result, the document feeder 3 can be opened, and the pressing roller 31 and the contact glass 32 can be cleaned. FIG. 2 is a schematic perspective view of the copying machine 1 as viewed obliquely from above, and shows a state in which the document feeder 3 is opened.

In the document feed roller pair 25 on the front side, for example, the upper roller 27 includes five cylindrical upper rollers 33, and the lower roller 28 includes nine cylindrical lower rollers 34. Each lower roller 34 of the lower roller 28 is formed of, for example, rubber,
It is rotatably held by one rotating shaft 35 extending in the left-right direction. The rotating shaft 35 is connected to a drive system (not shown). When a motor included in the drive system is driven, the rotating shaft 35 rotates, and each lower roller 34 rotates.

The lower rollers 34 of the lower roller 28 are arranged side by side at a predetermined interval A (for example, 10 cm) in the axial direction, and are held so that the outer peripheral surface slightly protrudes from the upper surface 2b of the housing 2. I have. Each upper roller 3 of the upper roller 27
Numeral 3 is rotatably held by a single rotating shaft 36 extending in the left-right direction. A predetermined interval A is provided in the axial direction so as to oppose the five lower rollers at the center of the lower roller 28 in the axial direction. Open side by side. Of the five upper rollers 33, a total of three upper rollers at both ends and the center in the axial direction are formed by, for example, a sponge, and the remaining two upper rollers are formed by, for example, POM (polyoxymethylene). Have been.

Each upper roller 33 of the upper roller 27 is held so that the outer peripheral surface slightly protrudes from the bottom surface 3a of the document feeder 3, and when the document feeder 3 is closed, the lower roller 28 is moved downward. The roller 34 is brought into pressure contact with a predetermined nip pressure. At the time of document conveyance, the upper roller 33 of the upper roller 27 pressed against the lower roller 28 is rotated by rotating the lower roller 28. Of the pair of document feed rollers 26 on the rear side, for example, the upper roller 29 includes nine cylindrical upper rollers 37, and the lower roller 30 also has a cylindrical lower roller 38.
And nine.

Each lower roller 38 of the lower roller 30 is formed of, for example, rubber, and has one rotating shaft 3 extending in the left-right direction.
9 rotatably held. The rotating shaft 39 is connected to the rotating shaft 3 of the lower roller 28 by, for example, a belt (not shown).
5, the rotating shaft 35 rotates with the rotation of the lower roller 28, and each lower roller 38 rotates. The lower rollers 38 of the lower roller 30 are arranged side by side at a predetermined interval A in the axial direction, and are held so that the outer peripheral surface slightly protrudes from the upper surface 2 b of the housing 2.

Each upper roller 37 of the upper roller 29 is rotatably held by a single rotating shaft 40 extending in the left-right direction, and is axially opposed to each lower roller 38 of the lower roller 30. They are arranged side by side with a predetermined interval A therebetween. Of the nine upper rollers 37, the fourth upper roller from the left and the fourth upper roller from the right are formed by, for example, POM, and the remaining seven upper rollers are formed by, for example, a sponge. I have.

Each of the upper rollers 37 of the upper roller 29 is held so that the outer peripheral surface slightly protrudes from the bottom surface 3a of the document feeder 3, and when the document feeder 3 is closed, the upper roller 37 is positioned below the corresponding lower roller 30. The roller 38 is brought into pressure contact with a predetermined nip pressure. When the original is conveyed, the upper roller 37 of the upper roller 29 pressed against the lower roller 30 is rotated by rotating the lower roller 30. Pressing roller 31
Includes, for example, a single cylindrical roller 41 and a rotating shaft 42 that rotatably holds the roller 41. The rotation shaft 42 is connected to the rotation shaft 40 of the upper roller 29 of the rear document transport roller pair 26 by a belt (not shown).

The roller 41 of the pressing roller 31 is held so that the outer peripheral surface slightly protrudes from the bottom surface 3a of the document feeder 3. When the document feeder 3 is closed, the roller 41 is pressed against the contact glass 32 with a predetermined pressure. It is supposed to be. At the time of document conveyance, the rotation shaft 42 rotates with the rotation of the upper roller 29 of the rear document conveyance roller pair 26,
1 rotates. Contact glass 32
The document passing above is conveyed backward while being pressed by the roller 41 so as not to float off the contact glass 32.

In the present embodiment, in the document feed roller pair 25 on the front side, the central portion in the width direction of the document is conveyed by the upper roller 33 and the lower roller 34 of the lower roller 28 which are pressed against each other. Are transported only by the lower roller 34 of the lower roller 28. Therefore, the contact width between the upper roller 27 and the document can be shortened, so that wrinkles can be prevented from being formed at both ends of the document. In particular, since the upper rollers 33 of the upper roller 27 are arranged side by side at a predetermined interval A in the axial direction, the contact width between the upper roller 27 and the document can be further reduced.
Therefore, it is possible to further prevent the original from wrinkling.

The present invention is not limited to the contents of the above embodiments, and various changes can be made within the scope of the claims. For example, the predetermined interval A is not limited to 10 cm and may be larger or smaller. The number of the upper rollers 27 of the document transport roller pair 25 on the near side is not limited to the one formed by the five upper rollers 33, and may be four or less or six or more. The upper rollers 29 of the rear document transport roller pair 26 are not limited to those configured by the same number of upper rollers 37 as the corresponding lower rollers 30. For example, like the front document transport roller pair 25,
The lower roller 30 may be constituted by the upper rollers 37 that are smaller in number than the lower rollers 38.

The rollers 33, 34, 37, 38 are not limited to the above-mentioned materials, but may be made of, for example, rubber. Each upper roller 27, 29 and lower roller 28, 30
Is not limited to a single roller, but may be a single roller extending in the left-right direction.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration of a copying machine according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view of the copier viewed from obliquely above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copier 2b Upper surface (document conveyance path) 13 Scanner 25, 26 Document conveyance roller pair 27, 29 Upper roller 28, 30 Lower roller 33, 37 Upper roller 34, 38 Lower roller

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H076 BA14 BA16 BA24 3F049 AA01 DA11 DA12 DB02 LA02 LA05 LA07 LB02 5B047 AA01 BA01 BC18 5C062 AA05 AB02 AB32 AD01 AD06 BA00 5C072 AA01 BA13 BA20 NA01 XA01

Claims (2)

[Claims] An image forming apparatus having a document reading device capable of reading a document having a width of at least A1 size, comprising: a plurality of documents arranged in a document transport path for transporting the document and arranged in the width direction of the document; The plurality of rollers are configured to have a plurality of lower rollers and a smaller number than the lower rollers, and a pair of the lower rollers is pressed from above against a roller at a central portion in the width direction of the document to form a pair. An image forming apparatus comprising a plurality of upper rollers. 2. The document reading apparatus according to claim 1, wherein the document reading device includes a scanner for reading the document, wherein the plurality of rollers are arranged in pairs in a document conveying direction, and at least one of the plurality of pairs of rollers is arranged with respect to the scanner. 2. The image forming apparatus according to claim 1, wherein the roller disposed on the front side in the document conveying direction has a configuration according to claim 1.