JPH0517034A - Image formation device - Google Patents

Abstract

PURPOSE:To facilitate the additional furnishing of an option cassette to a device main body by improving the transport precision of a sheet material fed to the device main body from the option cassette. CONSTITUTION:A device main body 2 is mounted at the upper surface of an option feeder unit 3 through positioning members 3a. A paper feed roller 61, a transport roller 62, a transport roller 63 and a rotary plate 65 are provided at the upper part of the feeder unit 3. The rotary plate 65 adopts a standing up position M1 as occasion demands, and guides a sheet material P2 by means of upper and lower guides 65a, 65b, a butting guide 65c. At an option cassette 30 furnished attachably/ detachably at the feeder unit 3, a sheet regulating spring 36 to press the side end edge of the sheet material P2 against a transport reference surface 35 is arranged. As a result, the sheet material P2 that is fed to the device main body 2 from the option cassette 30 through the rotary plate 65, is pressed against the butting guide 65c and transported, and its transport precision is improved.

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 that selectively feeds paper from an internal paper feeding device and an external paper feeding device provided inside and outside the main body of the apparatus, and more specifically, to an external paper feeding device. The present invention relates to a paper feed mechanism that improves the accuracy of conveying a sheet material from a paper device.

[0002]

2. Description of the Related Art As shown in FIG. 6, there is known an image forming apparatus 100 in which paper feeding cassettes (paper feeding devices) 102 and 103 are mounted in multiple stages (two stages in the same figure) on an apparatus main body 101.

The sheet feeding cassettes 102 and 103 are detachably attached to the apparatus main body 101, and the sheet materials P1 and P2 stored therein are urged upward by the intermediate plates 105 and 106, respectively.

The uppermost sheet material P1 in the upper paper feed cassette 102 is fed by the rotation of the paper feed roller 107, guided by the conveyance guide 109, and the retard roller pair 1 is fed.
Guided to 10. The skew of the sheet material P1 is corrected by the pair of registration rollers 110, and the sheet material P1 is supplied to the photosensitive drum 111 and the transfer drum 112 at a predetermined timing, and the toner image is transferred.

This toner image is previously formed on the photosensitive drum 111. In the image forming unit 113 including the photosensitive drum 111, a primary charger, a developing device, a cleaning device, and the like (not shown) are arranged around the photosensitive drum 111. The surface of the photosensitive drum 111 is charged by the primary charger, a latent image is formed by the laser light L emitted from the scanner unit 115, and then the developing device develops the latent image with toner. It is transferred onto the sheet material P1.

The sheet material P on which the toner image has been transferred is conveyed along a conveying guide 116, and is fixed by a fixing device 120 including a transfer roller 117, a pressure roller 119, etc., and then a sheet discharge roller pair 121 is applied. Output tray 122
Is discharged to.

On the other hand, the sheet material P2 of the lower sheet feeding cassette 103 is fed by the rotation of the sheet feeding roller 123,
It is conveyed along the conveyance guide 126 by the conveyance roller pair 125. The sheet material P2 that has reached the registration roller pair 110 is then formed with a toner image in the image forming unit 113 in the same manner as the sheet material P1 from the upper sheet feeding cassette 102, and finally, on the paper discharge tray 122. Is discharged to.

By the way, the positional accuracy (image forming accuracy) of the toner images formed on the sheet materials P1 and P2, that is, the correct position in the front-back direction (conveying direction) and the lateral direction (left-right direction) of the sheet materials P1 and P2. Whether or not a toner image is formed is
It depends largely on the conveyance accuracy of the sheet materials P1 and P2, and the conveyance accuracy is secured by the registration roller pair 110 in the front-back direction.

[0009]

However, in the above-mentioned conventional example, the sheet materials in the sheet feeding cassettes 102 and 103 are secured because the sheet materials P1 and P2 are secured in the lateral direction, for example, because there is no abutting and conveying means. Slight deviations in the storage positions of P1 and P2 and the alignment of the paper feed rollers 107 and 123 adversely affect the image forming accuracy in the lateral direction. In order to ensure the image forming accuracy, it is necessary to assemble or adjust the sheet feeding devices 102 and 103 in the device main body 101 at the factory even if they are integrated with the device main body 101 or if they are separate types. Therefore, the user or the like had to select whether or not to use the plurality of sheet feeding devices 102 and 103 before installing the image forming apparatus 100. In addition, a user who purchases the image forming apparatus 100 having only one sheet feeding apparatus has to inconvenience that the apparatus main body 101 has to be newly purchased when a plurality of sheet feeding apparatuses are required after the apparatus is installed. occured.

In view of this, the present invention improves the conveyance accuracy of the sheet material by providing an option feeder unit equipped with an external sheet feeding device with an abutting guide and an abutting means for guiding the side edge of the sheet material. It is an object of the present invention to provide an image forming apparatus in which a paper feeding device can be easily added.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and, as shown with reference to FIGS. 1 and 3, is detachably attached to a lower portion of an apparatus main body (2). Sheet materials (P1, P2) are selectively fed from an internal paper feeding device (5) and an external paper feeding device (30) in an optional feeder unit (3) connected to the lower part of the device body (2). Paper and attach the sheet material (P1, P2) to the device body (2)
In the image forming apparatus (1) that feeds the image to the image forming unit (13) via the inner conveyance guide (7), the internal sheet feeding device (5) is fed from the external sheet feeding device (30). The sheet feeding slit (52) for guiding the sheet material (P2) to the conveyance guide (7), while the optional feeder unit (3) guides one side edge of the sheet material (P2). A guide (65c) is provided, and an upright position (M1) is set corresponding to the absence of the internal sheet feeding device (5), and the sheet material (P2) is guided to the transport guide (7) at the upright position (M1). A transport guide member (65) for
The sheet material (P2) of the external sheet feeding device (30) is fed to the sheet feeding slit (52) or the conveyance guide member (65).
To the external paper feeding device (3)
Abutting means (36, 70) for pressing the sheet material (P2) fed from 0) against the abutting guide (65c)
And having.

[0012]

According to the above construction, when the sheet material (P1) is fed from the internal sheet feeding device (5), the sheet material (P1)
1) is guided by the conveyance guide (7) and accurately conveyed to the image forming section (13). Also, the internal paper feeder (5)
When the sheet material (P2) is fed from the external sheet feeding device (30) in a state where the sheet material (P2) is attached, the sheet material (P2) is struck by the abutting means (36, 70) on one side of the sheet material (P2). The edge is the paper feed slit (52) and the transport guide (7)
It is guided to and conveyed accurately.

Further, when the internal paper feeding device (5) is removed (when it is absent), the conveying guide member (65) takes the standing position (M1) and the sheet material (P2) is placed in the main body (2) of the device. Guide it smoothly to the side transport guide (7). Since the conveyance guide member (65) is provided with an abutting guide (65c) that guides one side edge of the sheet material (P2), the abutting means (36, 70) causes the sheet material (36, 70) to move. P
2) can be pressed against the butting guide (65c). As a result, the lateral position of the sheet material (P2) conveyed from the external sheet feeding device (30) to the conveyance guide (7) of the apparatus main body (2) via the conveyance guide member (65) is accurately regulated. Has been done.

The reference numerals in the parentheses are for reference to the drawings and do not limit the structure of the present invention.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

The image forming apparatus 1 comprises an apparatus main body 2 placed on the upper surface of an option feeder unit 3 as shown in FIG.

An internal paper feeding device (paper feeding cassette) 5 for accommodating the sheet material P1 is detachably arranged at the lower part of the apparatus main body 2. The paper feed cassette 5 is the bottom plate 2 of the apparatus body 2.
It is mounted by sliding it in the direction of arrow A1 with respect to a and pulling it out in the direction of arrow A2. The paper feed cassette 5 will be described in detail later.

Above the paper feed cassette 5, the sheet material P in the paper feed cassette 5 is rotated by rotating in the direction of arrow R1.
A paper feed roller 6 for sequentially feeding 1 in the direction of arrow K1 from the topmost one is arranged. A conveyance guide 7 that guides the fed sheet material P1 is formed on the downstream side of the sheet feeding roller 6. In addition to the guide plates 7a and 7b that guide the front and back sides of the sheet material P1 so as to face each other to the transport guide 7, one of the left and right end edges of the sheet material P1, for example, the right side in the transport direction K1. It is assumed that a reference guide plate (not shown) for guiding the edge is provided. On the downstream side of the transport guide 7, the skew of the sheet material P1 is corrected and
Registration rollers 9a and 9b for adjusting the supply timing of the sheet material P1 are provided, and a conveyance guide 10 that guides the sheet material P1 to the photosensitive drum 11 is provided downstream of the registration rollers 9a and 9b. Has been done. The photosensitive drum 11 is rotatably arranged in an image forming unit (process cartridge) 13 which is detachably mounted on the apparatus main body 2. The process cartridge 13 contains a primary charger, a developing device, a cleaning device, etc., which are not shown, so that the latent image on the photosensitive drum 11 is visualized by toner. The latent image on the photosensitive drum 11 is formed by reflecting the laser light L emitted from the scanner unit 15 by the mirror 16 and scanning the charged photosensitive drum 11 with the laser light L.
Downstream of the transfer roller 12 paired with the photosensitive drum 11,
A conveyance guide 17 and a fixing device 19 are provided. The fixing device 19 includes an inlet guide 20, a fixing roller 21, a pressure roller 22, and fixing paper discharge rollers 23a and 23b, and a paper discharge guide 25 and paper discharge rollers 26a and 26b are provided downstream of the fixing device 19. Is provided. A discharge tray 27 for stacking the sheet material P1 after completion of copying is formed on the downstream side of the discharge rollers 26a and 26b, that is, in the upper part of the apparatus main body 2.

The sheet feeding cassette 5 is a middle plate 50 that stacks sheet materials P1 and urges the leading end side (right side in FIG. 1) upward.
Is equipped with. The paper feed guide 5 is provided just in front of the middle plate 50.
1. A sheet feeding slit 52 is formed. Paper feed guide 5
Reference numeral 1 is for guiding the sheet material P1 in the paper feed cassette 5, and the upper end of the paper feed slit 52 is opened to the lower end of the transport guide 7 on the apparatus body 2 side, while the lower end is the bottom plate 2a of the apparatus body 2. It is opened above the option feeder unit 3 through the through hole 2b formed in the. That is, the paper feed slit 52 penetrates the paper feed cassette 5 in the vertical direction,
The sheet material P2 in the option feeder unit 3 is guided to the conveyance guide 7. Paper cassette 5
A handle 53 used when the paper cassette 5 is taken in and out is formed at the front end of the.

The optional feeder unit 3 is arranged below the apparatus main body 2, that is, directly below the paper feed cassette 5. The optional feeder unit 3 is an external sheet feeding device (optional cassette) for storing a large number of sheet materials P2.
30 is detachably attached. The sheet material P1
The sheet material P2 and the sheet material P2 are distinguished in this way based on the fact that they are stored in different places. Optional cassette 30
Has an intermediate plate 31 similar to the intermediate plate 50 of the sheet feeding cassette 5 and urges the front end side of the sheet material P2 upward. , Handle 3
Have three. In addition, in the option cassette 30, FIG.
As shown in the figure, one side edge of the sheet material P2 is regulated to form a conveyance reference surface 35 which serves as a positioning reference in the left-right direction. A sheet restricting plate 37 having an abutting means (sheet restricting spring) 36 for pressing the other side edge of the sheet material P2 is disposed at a position facing the transport reference surface 35. The option cassette 30 is slid in the direction of arrow B1 to be inserted into the option feeder unit 3, and is slid in the direction of arrow B2 to be pulled out.

A paper feed mechanism 60 for feeding the sheet material P2 in the option cassette 30 to the apparatus main body 2 is mounted on the upper part of the option feeder unit 3.
The sheet feeding mechanism 60 includes a sheet feeding roller 61 rotatably attached to the option feeder unit 3, a pair of conveying rollers 62, and a conveying roller 63. Paper feed roller 61
Is pressed against the uppermost sheet material P2 with a predetermined pressure and is rotated, so that the sheet material P2 is fed with the sheet feeding guide 32,
The paper is fed toward the carrying roller 62, and the carrying roller 6
The sheet material P2 is sandwiched between the two and the transport roller 63, and the sheet material P2 is transported toward the apparatus main body 2.

A transport guide member (rotating plate) 65 is arranged near the transport roller 62. The rotating plate 65 includes upper and lower guides 65a, 65 for guiding the front and back surfaces of the sheet material P2.
b, and an abutment guide 65c for guiding one side edge of the sheet material P2, and is swingably supported about a shaft 66 on the base end side. Further, the shaft 66 has a torsion spring 69 whose both ends are engaged with a rotating plate 65 and a stopper 67, respectively.
Is attached (see FIG. 1), whereby the rotating plate 65 is
It is biased in the direction of arrow C1 and takes a retracted position M2 and an upright position M1 depending on the presence or absence of the paper feed cassette 5 in the apparatus body 2. That is, the rotating plate 65
When the paper feed cassette 5 is attached to the apparatus main body 2, the paper feed cassette 5 swings in the direction of arrow C2 against the elastic force of the torsion spring 69 and takes the retracted position M2. The retracted position M2 is maintained throughout the period when the paper feed cassette 5 is mounted, and at this time, the sheet material P2 fed by the paper feed roller 61 is fed by the paper feed guide 32, the conveyance roller 62, and the conveyance roller 63. , Paper feed slit 5 of paper feed cassette 5
It reaches the conveyance guide 7 via 2. On the other hand, when the paper feed cassette 5 is not inside the apparatus main body 2, the torsion spring 6
The elastic force of 9 causes the device main body 2 to swing in the direction of arrow C1.
The upright position B2 protruding from the through hole 2b of the bottom plate 2a is taken (see FIG. 3). At this time, the base end of the rotary plate 65 is close to the upper end of the paper feed guide 32, while the front end of the rotary plate 65 is close to the lower end of the transport guide 7. As a result, the rotary plate 65 is removed from the sheet feeding slit 52 of the sheet feeding cassette 5.
Instead of the sheet material P from the optional cassette 30
2 can be guided to the transport guide 7.

To attach the optional feeder unit 3 to the apparatus main body 2, the positioning members 3a protruding from the upper surfaces of the four corners of the optional feeder unit 3 are fitted into the positioning holes 2c formed in the bottom plate 2a of the apparatus main body 2. By doing so, the relative positional relationship between each constituent member inside the apparatus main body 2 and each constituent member inside the option feeder unit 3 can be accurately matched. That is, the lateral conveyance accuracy of the sheet material P2 from the optional feeder unit 3 at the time of feeding the photosensitive drum 11 is particularly problematic. With reference to the reference, the transfer reference surface 35 of the option cassette 30 and the rotating plate 6
5, the abutting guide 65c is positioned, while the apparatus main body 2 side uses the positioning hole 2c as a reference and the sheet feeding slit 5
2, the transport guide 7 etc. are positioned,
As a result, even when the rotating plate 65 takes the upright position M1, the abutting guide 65c of the rotating plate 65 and the conveyance guide 7
The position of the reference guide plate and the position of the reference guide plate match well.

Next, the operation of the above-described embodiment will be described in three cases centering on the lateral alignment of the sheet materials P1 and P2. The case of three means the device body 2
When the sheet material P1 is fed from the sheet feeding cassette 5 attached to the sheet feeding cassette 5, the sheet feeding cassette 5 is attached to the apparatus main body 2. However, from here, the option cassette 30 attached to the option feeder unit 3 is not fed. From sheet material P2
Is when the sheet material P2 is fed from the option cassette 30 of the option feeder unit 3 when the sheet feeding cassette 5 is not attached to the apparatus main body 2.

The sheet material P1 fed in the direction of arrow K1 by the rotation of the feed roller 6 rises along the paper feed guide 51, and is guided by one side edge by the reference guide plate of the conveyance guide 7. While being registered, the registration roller 9a,
It is transported to 9b. The sheet material P1 is the registration roller 9
The skew feeding is corrected by a and 9b, and the light is supplied to the photosensitive drum 11 at the same timing. A toner image is transferred onto the sheet material P1 by the photosensitive drum 11, and then the toner image is fixed by the fixing device 19, and then the sheet material P1 is finally discharged onto the paper discharge tray 27.

The rotary plate 65 in the option feeder unit 3 is set in the retracted position M2 by the paper feed cassette 5 in the main body 2 of the apparatus. The sheet material P2 of the option cassette 30 of the option feeder unit 3 is the paper feed roller 61.
The paper is fed in the direction of arrow K2 by the rotation of the paper feed guide 3
2. It is conveyed to the registration rollers 9a and 9b via the conveyance guide 7 through the sheet feeding slit 52. At this time, the sheet material P2 has one side edge (in this embodiment, the right side edge in the transport direction) of the option cassette 30.
The sheet is fed while being pressed against the conveyance reference surface 35 by the sheet regulating spring 36 inside, and the right side edge of the sheet material P2 is then fed to the sheet feeding slit 52 of the sheet feeding cassette 5.
The sheet is conveyed to the registration rollers 9a and 9b while being guided by the reference guide plate of the conveyance guide 7. After that, the toner image is formed on the sheet material P2 in the same manner as.

On the basis of the fact that the paper feed cassette 5 is not inside the apparatus main body 2, the rotary plate 65 takes the upright position M1. As a result, the sheet material P2 fed by the sheet feeding roller 61
Is conveyed through the paper feed guide 32 and the rotary plate 65.
Enter. The right side edge of the sheet material P2 is pressed against the conveyance reference surface 35 by the sheet regulation spring 36 in the same manner as, and then enters the conveyance guide 7 while being guided by the abutting guide 65c of the rotating plate 65, It is guided by the reference guide plate and reaches the registration rollers 9a and 9b. The right edge of the sheet material P2 is firmly guided by the rotating plate 65 at the upright position M1 despite the absence of the sheet feeding cassette 5. The operation after the registration rollers 9a and 9b is the same as.

As described above, the paper feeding mechanism 60 and the rotary plate 65.
However, since the option feeder unit 3 is mounted on the side of the main body device 2,
If the option feeder unit 3 is secured only on the side of the option feeder unit 3 independently from the side, and then the option feeder unit 3 and the main body device 2 are accurately connected via the positioning member 3a or the like, the conveyance accuracy of the sheet material P2 can be improved. You can secure enough.

4 and 5, another embodiment in which a part of the option cassette 30 and the paper feed mechanism 60 is changed from the previous embodiment will be described.

In another embodiment shown in FIG. 4, the sheet regulating spring 36 is positively omitted from the sheet regulating plate 37, and further,
An oblique feed roller 70 is provided instead of the transport roller 63. The shaft of the skew feed roller 70 is arranged so as to be inclined with respect to the shaft of the transport roller 62. As a result, the transport roller 62 and the skew feed roller 7
When the sheet material P2 is sandwiched between 0 and
The skew feeding roller 70 presses the right edge of the sheet material P2 against the conveyance reference surface 35, the abutting guide 65c, and the like.

In the embodiment shown in FIG. 5, a carrying roller 62 and a carrying roller 63 are additionally attached to the embodiment shown in FIG. By the combination of the transport roller 62 and the transport roller 63,
The sheet material P2 is supplied with a sufficient conveying force to more stably feed the sheet material.

[0032]

As described above, according to the present invention,
By arranging the abutting guide and abutting means for improving the lateral conveyance accuracy of the sheet material on the option feeder unit side, the sheet material is fed from the external paper feeding device in the option feeder unit to the main body of the device. Even in this case, the lateral conveyance accuracy can be maintained sufficiently high.

This eliminates the need for complicated precision adjustment when assembling the external sheet feeding device to the apparatus main body, makes it easy to attach / detach the external sheet feeding device to / from the apparatus main body, and allows the user to easily attach the external sheet feeding device to the external body depending on the use condition. It is possible to additionally install a paper feeding device.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing the entire image forming apparatus.

FIG. 2 is an operation explanatory diagram of a main part.

FIG. 3 is a perspective explanatory view showing an optional feeder unit and an optional cassette.

FIG. 4 is a perspective explanatory view showing another embodiment of the option feeder unit and the option cassette.

FIG. 5 is a perspective explanatory view showing another embodiment of the option feeder unit and the option cassette.

FIG. 6 is a vertical sectional side view showing a conventional image forming apparatus.

[Explanation of symbols]

 1 Image Forming Device 2 Device Main Body 3 Optional Feeder Unit 5 Internal Paper Feeding Device (Paper Feeding Cassette) 7 Conveying Guide 13 Image Forming Section (Process Cartridge) 30 External Paper Feeding Device (Optional Cassette) 36 Abutting Means (Sheet Regulation Spring) 52 Paper Feed Slit 60 Paper Feed Mechanism 65 Conveying Guide Member (Rotating Plate) 65c Abutting Guide 70 Abutting Means (Slant Feeding Roller) M1 Standing Position P1, P2 Sheet Material

Claims (1)

What is claimed is: 1. An internal sheet feeding device that is detachably attached to a lower portion of an apparatus main body, and an external sheet feeding device inside an option feeder unit that is connected to a lower portion of the apparatus main body. An image forming apparatus configured to feed a sheet material and feed the sheet material to an image forming unit via a conveyance guide in the apparatus main body, wherein the internal sheet feeding device is a sheet from the external sheet feeding device. While having a paper feed slit that guides the material to the conveyance guide, the optional feeder unit includes a butting guide that guides one side edge of the sheet material and stands up in response to the absence of the internal paper feeding device. A conveyance guide member that takes a position and guides the sheet material to the conveyance guide at the standing position, and feeds the sheet material of the external sheet feeding device to the sheet feeding slit or the conveyance guide member. Having a paper mechanism and abutment means for pressing the sheet material to be fed paper from said external sheet feeding apparatus to the abutment guide, that the image forming apparatus according to claim.