JP2001261182A - Sheet carrier and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet carrier mountable of a large driving means with a simple structure and easy to maintain, and an image forming device equipped with the carrier. SOLUTION: This sheet carrier comprises a carrying roller 35 for carrying a sheet and a carrying motor 40 for driving the carrying roller 35. The carrying motor 40 is arranged on the front side of a device body.

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 copying machine, a printer, and the like, and an image forming apparatus using the same.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer, a sheet is conveyed by a conveying roller and an image is formed on the sheet. At this time, there is an apparatus in which a conveying member is formed into a unit so that a jammed sheet (paper jam) can be easily removed in the middle of the conveying path and can be pulled out from the apparatus main body.

For example, as shown in FIG. 4, a transport unit 51 is configured to be able to be pulled out in the direction of arrow A with respect to the image forming apparatus main body 50, and is supported by left and right rails 52a and 52b to be attached to the apparatus main body 50. It is stored. Then, the transport roller 53 is rotated by the drive motor 54, and the sheet is transported by the rotation.

Thus, when a sheet is jammed in the vicinity of the conveying roller 53, the jam can be easily cleared by pulling out the conveying unit 51.

[0005]

However, in the conventional image forming apparatus, a motor for driving the transport roller 53 is used.
Since the 54 was attached to the rear plate 55 of the transport unit 51, and its electric boards and wiring members were also concentrated in the vicinity of the motor 54, the heat generated by them was easily trapped. In particular, when the conveying roller 53 has a large diameter, the motor 54 for driving the conveying roller 53 also becomes large, and the heat generated by the inertia and the self-heating of the motor increases.

Therefore, when the size of the drive motor 54 is increased, it is necessary to provide a cooling fan or a duct, which complicates the apparatus and increases the cost.

If the drive motor 54 is to be removed for maintenance of the transport unit 51, it cannot be removed unless the entire transport unit is removed from the apparatus main body, resulting in poor work efficiency.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a sheet transporting apparatus which can be mounted with a large driving means with a simple structure and which is easy to maintain, and an image forming apparatus having the same. An apparatus is provided.

[0009]

A typical configuration according to the present invention for achieving the above object has a transport roller for transporting a sheet, and a driving unit for driving the transport roller. The driving means is arranged on the front side of the apparatus main body.

In the above configuration, the heat generated by the driving means can easily escape from the front side of the apparatus. In an image forming apparatus in which the sheet conveying apparatus can be pulled out, the driving means is pulled out by pulling out the sheet conveying apparatus. A flow of fresh air is generated in the vicinity, and self-heating by the driving means is prevented. Further, maintenance of the driving means can be easily performed only by pulling out the sheet conveying device.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a sheet conveying apparatus according to an embodiment of the present invention will be described with reference to the drawings, using the same as an image forming apparatus. 1 is a perspective explanatory view showing a state where the sheet conveying device is pulled out from the apparatus main body, FIG. 2 is an overall sectional explanatory view of the image forming apparatus, and FIG. 3 is a sectional explanatory view of the sheet conveying apparatus.

(Image Forming Apparatus) First, the overall structure of the image forming apparatus A will be described. In FIG. 2, reference numeral 1 denotes an apparatus main body, which is formed of a transparent glass plate fixedly provided on the upper part of the apparatus main body 1. A document table 2 is provided. Reference numeral 3 denotes a document pressing plate, which presses and fixes a document O placed at a predetermined position on the document table 2 with the image surface facing downward.

A lamp 4 for illuminating the original O, a reflection mirror 5 for guiding the illuminated light image of the original O to the photosensitive drum 12, and a light source 4 are provided below the original table 2. Image lens
11 is provided. In addition, lamp 4
The reflecting mirrors 5, 6, and 7 move at a predetermined speed in the direction of arrow a to scan the original O.

The image forming means includes a photosensitive drum 12, a charger 13 for uniformly charging the surface of the photosensitive drum 12, and a surface of the photosensitive drum 12 charged by the charger 13 irradiated from the optical system. Developing unit 14 for developing the electrostatic latent image formed by the light image to form a toner image to be transferred to the sheet S, and transferring the toner image developed on the surface of the photosensitive drum 12 to the sheet S And a separation charger 16 for separating the sheet S on which the toner image has been transferred from the photosensitive drum 12, and a photosensitive drum after transferring the toner image.
12 is provided with a cleaner 17 for removing the residual toner.

The sheet feeding units are cassette sheet feeding units 22, 23, 24, and 25 for feeding sheets stacked in sheet cassettes 18, 19, 20, and 21 built in the apparatus main body 1 to image forming means. Paper feed units 27, 28, 29, 30 for continuously feeding sheets of various materials and various sizes from the paper feed tray 26 to the image forming means are provided.

A transport unit 31 for transporting the sheet S on which the toner image has been transferred is provided downstream of the image forming means.
A fixing unit 32 for fixing an image on the sheet S conveyed by the printer as a permanent image is provided. In addition, the fixing device 32
A discharge roller 33 is provided for discharging the sheet S on which the image has been fixed from the apparatus main body 1, and a discharge tray for receiving the sheet S discharged by the discharge roller 33 is provided outside the apparatus main body 1. 34 are provided.

In the image forming apparatus according to the present embodiment, an image is recorded on one side of the sheet S, and then the sheet is inverted and transported to the image forming means again. A transport unit B is provided.

(Sheet Conveying Apparatus) Next, the conveying unit B will be described. In the transport unit B, as shown in FIG. 2, the transport roller 35 is provided so as to be rotatable forward and backward.
The transport roller 35 has a driven roller 36a at two places,
36b is energized. A guide member 36c is provided so as to face at least a part of the outer peripheral surface of the transport roller 35,
A curved sheet conveying path is formed along the outer peripheral surface of the conveying roller 35. These are the front side plate 39a of the transport unit B.
And is supported by the rear side plate 39b. When recording is performed on both sides of the sheet, after the sheet on which image recording has been performed on one side passes through the fixing device 32, the sheet is conveyed downward by a flapper (not shown) and conveyed by the conveyance rollers 35. ing.

The transport roller 35 reverses the sheet on which single-side recording has been performed and transports the sheet again to the image forming means.
By switching the swingable flapper 37, as shown in FIG. 3, along the peripheral surface of the transport roller 35, along the path for transporting the sheet from arrow a to arrow b, and along the peripheral surface of the transport roller 35. Two transport routes, which are routes for transporting in the direction of arrow c → d, are formed. The transport roller 35 is configured as a roller having such a large diameter that the sheet is not bent when the sheet is conveyed while being curved along the peripheral surface. That is, the transport roller
Reference numeral 35 denotes a large diameter having a curvature substantially equal to or less than the curvature of the curved portion having an outer peripheral surface with an inner diameter surface of a curved portion forming a sheet transport path communicating the two transport paths curved along the outer peripheral surface of the roller. It is configured as a roller.

When reversing and re-feeding the sheet by the conveying roller 35, the conveying roller 35 is rotated clockwise to convey the sheet from the conveying path a to the conveying path b. Thereafter, the conveying roller 35 is rotated counterclockwise to move the sheet to the conveying path c →
d, and the sheet is again conveyed to the image forming means by the re-feed roller 38 or the like.

As shown in FIG. 1, the transfer unit B is slidably mounted on the apparatus main body 1 by rails 38a and 38b, and can be pulled out from the apparatus main body 1 to the front side of the apparatus as indicated by an arrow a. Yes, it is removable. Accordingly, when the sheet is jammed in the portion of the conveyance unit B, the jam can be easily removed by pulling out the conveyance unit B in a direction substantially transverse to the sheet conveyance direction.

Here, the front side plate 39a of the transport unit B
Is a transport motor serving as a driving unit for driving the transport roller 35
40 are installed. The transport motor 40 is attached to the outside of the front plate 39a, and the drive shaft of the transport motor 40 (not shown) passes through the front plate 39a and enters the inside of the front plate 39a,
A motor pulley (not shown) is attached to this drive shaft.By connecting the pulley and a roller pulley (not shown) attached to the shaft end of the transport roller 35 with a belt, the driving force of the transport motor 40 is applied to the transport roller 35. To be transmitted. The electric boards and wiring members of the apparatus excluding the electric board of the transfer motor 40 are arranged inside the apparatus (for example, on the side of the rear plate of the transfer unit).

As described above, by attaching the drive means of the transport unit B to the front side plate 39a, fresh air flows through the transport motor 40 every time the transport unit is pulled out, thereby preventing self-heating of the motor. Is done.
Therefore, it is not necessary to provide a fan, a duct, or the like for cooling the transport motor 40, and it is possible to eliminate a factor of cost increase.

Further, since the transport motor 40 is exposed when the transport unit B is pulled out, maintenance of driving means such as the transport motor can be easily performed.

In the above-described embodiment, an example in which the transport unit is used in the image forming apparatus has been described. However, this transport unit is used, for example, in a reading device that transports a double-sided original and reads the written information by the reading means. Can also be used.

[0026]

The present invention is constructed as described above.
The heat generated by the driving means can easily escape from the front of the device,
In the image forming apparatus in which the sheet conveying device can be pulled out, the flow of fresh air is generated in the vicinity of the driving unit by pulling out the sheet conveying device, and the self-heating by the driving unit is prevented. Further, maintenance of the driving means can be easily performed only by pulling out the sheet conveying device.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view showing a state in which a sheet conveying device is pulled out from an apparatus main body.

FIG. 2 is an overall sectional explanatory view of the image forming apparatus.

FIG. 3 is an explanatory sectional view of a sheet conveying device.

FIG. 4 is an explanatory view of a conventional sheet conveying apparatus.

[Explanation of symbols]

 A: Image forming apparatus B: Conveying unit O: Document S: Sheet 1: Apparatus main body 2: Document platen 3: Document pressing plate 4: Lamp 5, 6, 7, 8, 9, 10 ... Reflector mirror 11: Imaging lens 12 ... photosensitive drum 13 ... charger 14 ... developing unit 15 ... transfer charger 16 ... separation charger 17 ... cleaner 18, 19, 20, 21 ... sheet cassettes 22, 23, 24, 25 ... cassette feeding section 26 ... supply Paper trays 27, 28, 29, 30 Paper feed unit 31 Transport unit 32 Fixing unit 33 Discharge roller 34 Discharge tray 35 Transport rollers 36a, 36b Follower roller 36c Guide member 37 Flapper 38a, 38b Rail 39a: Front plate 39b: Rear plate 40: Transport motor

Claims (7)

[Claims] 1. A sheet conveying device, comprising: a conveying roller for conveying a sheet; and a driving unit for driving the conveying roller, wherein the driving unit is disposed on a front side of the apparatus main body. 2. A sheet conveying path that curves along the outer peripheral surface of the conveying roller and communicates two conveying paths,
2. The sheet conveyance device according to claim 1, wherein the conveyance roller is a large-diameter roller having a curvature substantially equal to or less than a curvature of the curved portion having an inner diameter surface of the curved portion forming the conveyance path as an outer peripheral surface. 3. apparatus. 3. The sheet conveying apparatus according to claim 1, wherein the conveying roller and the driving unit are configured as a conveying unit detachable from the apparatus main body. 4. The sheet conveying apparatus according to claim 3, wherein said conveying unit can be pulled out of the apparatus main body. 5. A conveying roller for conveying a sheet, a guide member facing at least a part of an outer peripheral surface of the conveying roller, and forming a curved sheet conveying path along the outer peripheral surface of the conveying roller; A driving unit for driving a roller, and a sheet conveyance device having a conveyance unit that can be pulled out in a substantially horizontal direction in a direction crossing the sheet conveyance direction from the apparatus main body. A sheet conveying device, which is arranged. 6. The sheet according to claim 5, wherein the transport unit has a side plate that supports the transport roller and the guide member, and the driving unit is attached to an outer side of the side plate from which the sheet is pulled out. Transport device. 7. An image forming apparatus for conveying a sheet to form an image, comprising: an image forming unit for forming an image on the sheet; and the sheet conveying apparatus according to claim 1. An image forming apparatus comprising: