JPH069068A - Image forming device - Google Patents

Abstract

PURPOSE:To effectively prevent not to transcribe a part of the image of a document on a sheet material or to transcribe a surplus toner on a sheet material by feeding paper sheet from a paper sheet feed tray only when the sheet material regulated with side guides is detected by a seat material detecting means. CONSTITUTION:A sheet material detecting means 26 is fitted in proximity to the guide face 23c of a side guide 23, and moved accompanying the side guide 23. Consequently, when a sheet material P on a paper feed tray 12 is detected by the sheet material detecting means 26 having a detecting object in the vicinity of the side end of the sheet material P, because the side guide 23 is arranged near by the side end of the sheet material P, the sheet material P at being fed is regulated onto a decided position with the guide face 23c of the side guide 23. Consequently, relative positional relation of a document, a photosensitive drum, a sheet material, and the like is correctly maintained, and the toner image to be transcribed from the photosensitive drum onto the sheet material can be transcribed on the suitable position of the sheet material.

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 provided with a sheet material conveying device for conveying a sheet material as an image forming object.

[0002]

[Prior art]

<Prior Art 1> Conventionally, an image forming apparatus which obtains an image by forming a toner image on an image carrier by an electrophotographic method, an electrostatic recording method, or the like and transferring the toner image onto a sheet material by a transfer electric field. Have been proposed. FIG. 7 is a sectional view showing an outline of an example of such an image forming apparatus.

A photosensitive drum 2 as an image carrier is rotatably supported in the direction of an arrow R1 at substantially the center of a main body 1 of the image forming apparatus. Around the photosensitive drum 2, a primary charger 3, a short-focus optical element array 5, a developing device 6, a transfer device 7, and a cleaner 9 are arranged in this order along the rotation direction. Then, the surface of the photosensitive drum 2 is uniformly charged by the primary charger 3, and then the document table 10 is reciprocated.
The original set above is illuminated by the light source lamp 11, and the reflected light is applied to the surface of the photosensitive drum 2 via the short-focus optical element array 5 to form an electrostatic latent image. Further, toner (developer) is attached to the electrostatic latent image by the developing device 6 to form a toner image.

On the other hand, the sheet material P set on the paper feed tray 12 is fed by a pair of paper feed rollers 13 and 15,
The timing is adjusted by the registration mechanism 16 and the sheet is sent to the transfer unit via the pair of registration rollers 17 and 19.
At the transfer portion, the toner image on the photosensitive drum 2 is transferred to the surface of the sheet material P. The sheet material P to which the toner image is transferred is then conveyed along the guide member 20,
The toner image is fixed by the fixing roller pair 21 and the discharge roller pair 2
It is discharged from the apparatus main body 1 via

In the above-described image forming apparatus, the sheet material P
Any size can be used as long as it can pass through the inside of the apparatus main body 1. However, for example, an A4 size sheet material P is vertically conveyed to an image forming apparatus capable of longitudinally feeding a maximum A3 size print, and the document size is larger than A4, or a document of A4 size or smaller is displaced from a predetermined position. The following problems occur when the printing operation is performed such that the printing plate is placed, or the surface that comes into contact with the original is white, and the pressure plate that should be used by being brought into close contact with the original is slightly lifted or completely opened.

As a first problem, for example, when an A4 original is placed and the pressure plate is completely opened to perform a printing operation, the toner is developed on the entire portion outside the central A4 width. FIG. 8 schematically shows the positional relationship between the developing state of the photosensitive drum 2 and the sheet material P at this time.
The shaded area on the photosensitive drum 2 in FIG. 8 is the area where the toner has been entirely developed, and the white area A in the center is developed corresponding to the original. In this case, since the portion A and the position of the sheet material P correspond to each other, there is no problem in the image obtained by printing, and the toner in the shaded portion is the cleaner 9
Removed by. However, the toner in the shaded area is not used effectively at all and is wasted, resulting in an increase in printing cost based on the running cost of the toner.

As a second problem, if another example is shown, when the sheet material P is to be conveyed with the center reference as described above, as shown in FIG.
3 should be moved in the left-right direction (perpendicular to the sheet feeding direction of the sheet material P) in accordance with the sheet size and set in a predetermined position, but when it is not set in the predetermined position, as shown in FIG. Problems arise. That is, since the sheet material P is conveyed while being displaced from the center, a part of the obtained image (hatched portion in the drawing) is completely black, and the area A ″ in the area corresponding to the document has the image as the sheet material. Not transferred to P.

Conventionally, for example, the following measures have been taken for the first problem. As shown in FIG. 11, the LED array 25 is provided around the photosensitive drum 2 in the apparatus main body 1 between the primary charger 3 and the developing device 6, and the opening width of the side guide 23 on the paper feed tray 12 is set. By turning on a part of the LED array 25 corresponding to the outer side,
The portion of the photosensitive drum 2 that touches the outside of the sheet material P does not undergo development. As a result, wasteful consumption of toner can be suppressed. <Prior Art 2> Conventionally, a manual paper feed mechanism is provided, and
A sheet feeding device provided with a U-shaped reversing path is known, and the sheet feeding device has a configuration as shown in FIG. Apparatus main body 50 of image forming apparatus such as small copying machine
The sheet feeding device S disposed in the above includes a cassette 51 for accommodating the sheet material P and an image forming section 52. The cassette 51 has an intermediate plate 53 on which the sheet material P is stacked and an intermediate plate 53.
A spring 55 for urging the sheet material P upward and a separation claw 56 for separating the sheet materials P one by one. A sheet feeding roller 57, which has a circular shape and which feeds the sheet material P, is disposed above the cassette 51, and the sheet material P is conveyed downstream of the roller 57 to the image forming unit 52. A sheet feeding device S is arranged. Further, the sheet feeding device S
Is an inner guide 59a forming a U-shaped inversion path 59,
The outer guide member 69, which has an outer guide 59b, is supported by a shaft 60 so as to be openable and closable so that a paper jam in the U-shaped reversing path 59 can be easily treated. Further, a conveyance roller pair 61 and a conveyance guide 62 are arranged downstream of the reversing path 59, and the sheet material P is placed on the image forming portion 52 downstream of the guide.
A pair of registration rollers 63 for synchronously transporting to is provided. In addition to the sheet feeding through the U-shaped reversing path 59, a manual sheet feeding port 65 is formed, and the manual sheet feeding port 65 is formed.
A manual feed guide 66 is provided to insert the sheet material P into the sheet.

When a start key (not shown) is pressed, the paper feed roller 57 starts rotating and the cassette 51
The sheet material P is fed from the sheet material, and only the uppermost sheet material P is separated by the separating claw 56 and is conveyed to the pair of conveying rollers 61 through the reversing path 59. Further, the sheet material P is conveyed by the conveying roller pair 61 through the conveying guide 62 to the registration roller pair 63, and is conveyed by the roller pair 63 in synchronism with the image of the image forming section 52.
To form an image. Similarly, the sheet material P inserted from the manual sheet feeding port 65 passes through the conveyance guide 67,
The presence of the sheet material P is recognized by a sensor (not shown),
The roller pair 61 starts to rotate, and the roller pair 6 is rotated as described above.
It is transported to 3. <Prior Art 3> In a main body of an image forming apparatus such as a printer, a copying machine, or a facsimile, a paper feed tray for stacking sheet materials to be fed into the main body of the apparatus, and a paper discharge from the main body of the apparatus. A paper discharge tray for stacking the sheet material to be loaded is provided.

The paper feed tray and the paper discharge tray are of a size capable of stacking the maximum usable sheet material in the image forming apparatus.

Further, the paper feed tray and the paper discharge tray are usually attached to opposite side surfaces of the apparatus main body.

FIG. 36 shows a conventional image forming apparatus (printer) having a paper feed tray 102 and a paper discharge tray 103 on opposite side surfaces 101A and 101B of the apparatus main body 101.

In this image forming apparatus, the paper feed tray 1
02 and the discharge tray 103 are the image forming apparatus main body 101.
On the other hand, they are attached via support shafts (connecting pins) 105 and 106, respectively. This is because when the image forming apparatus is not used, the paper feed tray 102 and the paper discharge tray 103 are folded and stored with respect to the apparatus main body 101, or the apparatus main body 10 is used.
This is because the storage space of the image forming apparatus can be reduced by removing it from the image forming apparatus 1.

Paper feed tray 102 and paper discharge tray 103
Can be folded up with respect to the apparatus main body 101 as shown by the chain double-dashed line in the figure by rotating the support shafts 105 and 106 upward. In the illustrated example, shafts (connecting pins) 107 and 109 that allow the trays 102 and 103 to be bent at the central portion are provided.

Further, the paper feed tray 102 and the paper discharge tray 1
03, when the support shafts 105 and 106 are pulled out, the device main body 1
It can be removed from 01. In this case, the device body 1
The paper feed tray 102 and the paper discharge tray 1 removed from 01
03 is stored in a storage unit or the like formed in the apparatus main body 101.

In FIG. 36, the paper feed tray 102 and the paper discharge tray 103 are shown as side surfaces 101A, 10A of the apparatus main body 101.
1B illustrates the image forming apparatus in a ready-to-use position installed in a predetermined state.

Sheet materials (not shown) stacked on the paper feed tray 102 are fed into the main body 101 of the apparatus one by one in order from the lowest paper. The sheet material fed by the paper feed roller pair 110 is fed until the leading end thereof enters the nip of the registration roller pair 111 whose rotation is stopped.

Next, the registration roller pair 111 is rotated in synchronization with the toner image on the photosensitive drum 112 rotating clockwise, and the sheet material is conveyed between the photosensitive drum 112 and the transfer charger 113. To do. Here, the toner image on the photosensitive drum 112 is transferred onto the upper surface of the sheet material by the transfer charger 113.

The sheet material after the transfer of the toner image is fixed by a fixing roller pair 116 by a conveyor belt 115 rotating counterclockwise.
Sent to. The toner image on the upper surface of the sheet material is heated and pressed by the fixing roller pair 116 to be fixed on the upper surface of the sheet material.

The sheet material that has undergone the fixing process is discharged onto the discharge tray 103 outside the apparatus by the fixing roller pair 116.

[0021]

[Problems to be Solved by the Invention]

<Problem of the First Invention> However, according to the above-mentioned conventional technique 1, there are the following drawbacks. That is, as the above-mentioned second problem, the phenomenon shown in FIG. 10 is not solved unless the position of the sheet material P is set correctly.

As a measure against the above-mentioned first problem, L
The sheet material P of the photosensitive drum 2 using the ED array 25 or the like.
Even the method of exposing the portion corresponding to the outer side of to prevent development from occurring, has the following drawbacks. That is,
When the side guide 23 is set to the A3 width position, the toner is not developed on an unnecessary portion, but as shown in FIG. 12, if the position of the sheet material P is not set correctly, A part (B portion) of the obtained image is pure white, and the area A ″ of the area corresponding to the document is not transferred to the sheet material P.

If the side guide 23 is set to a position wider than the A4 width and narrower than the A3 width and the sheet material P is set to a predetermined position, as shown in FIG. In addition, although there is no problem on the image, the shaded area is not used effectively and toner is wasted. At this time, if the electric field forming means for transferring the toner sheet material P on the photosensitive drum 2 is not a corona discharger but a transfer roller or the like, the toner in the shaded area is transferred to the transfer roller, resulting in Further, at the time of the next printing, the toner adheres to the back surface of the sheet material P, and the sheet material P is soiled.

Also, as in the case of the side guide 23
When the position of is set to a position wider than the width of A4 and narrower than the width of A3, and the sheet material P is not set to the predetermined position, as shown in FIG. Is black, and the area A ″ of the area corresponding to the original is not transferred.

Therefore, according to the first aspect of the present invention, the image forming is made to solve the above-mentioned problem by feeding the sheet material only when the sheet material detecting means moving along with the side guide detects the sheet material. The purpose is to provide a device. <Problem of Second Invention> Further, according to the second invention, there are the following problems.

For normal paper feeding, the cassette 51 is used, but the manual feed guide 66 is unnecessary when feeding the cassette. Even if it is folded and stored, it may get in the way or get dirty. Also, removing it may cause loss. On the other hand, if the sheet size cannot be conveyed by cassette feeding, only the manual feed guide 66 is required.
The character reversal path 59 is unnecessary.

However, the manual feed guide 66 and the U-shaped reversal path 59 must be provided for both of the two types of paper feeding, that is, manual feeding and cassette feeding, and either one of them must be provided. There was a drawback that it was very inconvenient.

Therefore, the second invention aims to provide an image forming apparatus in which the selection member can be used for two kinds of paper feeding by selectively switching and using the switching member. Is. <Problem of the Third Invention> Further, according to the third invention, the paper feed tray 102 and the paper discharge tray 103 must be folded or removed when they are stored in a predetermined place. Therefore, the handling of the image forming apparatus is very troublesome for a user who rarely uses the image forming apparatus or a user who feeds a small number of sheets. Further, when the paper feed tray 102 and the paper discharge tray 103 are folded, the image forming apparatus may be transported to the storage location while being folded.
There is a possibility that the paper feed tray 102 and the paper discharge tray 103 may be damaged.

In addition, the paper feed tray 102 and the paper discharge tray 103 have a size capable of stacking the maximum size sheet material used in the image forming apparatus.
02 and the size of the sheet discharge tray 103 plus the size of the apparatus main body 101 becomes the area occupied by the image forming apparatus during use. Therefore, there is a problem that the installation space for always using the maximum size sheet material is required to install the image forming apparatus even when the maximum size sheet material is not used.

Even if the sheet material to be used is not the maximum size, it is stacked on the paper feed tray 102 and the paper discharge tray 103 having the maximum size of the sheet material. There is also a problem that it takes a lot of time to take out the sheet material stacked in the. this is,
Normally, the paper feed tray 102 and the paper discharge tray 103 are attached in a state of being slightly inclined with respect to the image forming apparatus main body 101 as shown in the figure. For this purpose, the output tray 10
This is because the sheet material discharged onto the sheet 3 is stacked near the base end side of the tray and is positioned deeper than the tip end of the tray when it is not the maximum size sheet material.

Therefore, in the third invention, the paper feed tray and the paper discharge tray are easily accommodated in the main body of the image forming apparatus.
Moreover, it is an object of the present invention to provide an image forming apparatus capable of changing the occupied area of the paper feed tray and the paper discharge tray according to the size of the sheet material used.

[0032]

[Means for Solving the Problems]

<Means of First Invention> The first invention is a paper feed tray (12).
A side guide (23) that is movable in a direction intersecting the conveying direction (K1) of the sheet material (P) is provided on the upper side, and the guide surface (23c) of the side guide (23) allows the sheet material ( In the image forming apparatus equipped with a sheet feeding device for laterally positioning the sheet material (P) by regulating the side end of P) from the outside, the guide surface (23c) of the side guide (23) is A sheet material detecting means (26) that is movable with the side guides (23) and is capable of detecting the vicinity of the side edge of the sheet material (P) is provided.
Only when 6) detects the sheet material (P) regulated by the side guide (23), the paper feed tray (12)
The feature is that paper can be fed from. <Means of Second Invention> A second invention has at least two systems of sheet feeding means, and a sheet material conveying path (59) of one sheet feeding means and a sheet material insertion port (65) of the other sheet feeding means. ) And an image forming apparatus provided with a sheet material feeding device provided close to each other, a first position forming a part of the sheet material conveying path (59) and the sheet material insertion port (6).
A switching member (6) capable of selectively moving between a second position for guiding the sheet material (P) fed from (5) and the second position.
9) is included. <Means of Third Invention> A third invention relates to an apparatus main body (101).
In the image forming apparatus in which the paper feed tray (102) and the paper discharge tray (103) are respectively arranged on the side surfaces (101A, 101B) that oppose each other, the paper feed is performed on the apparatus main body (101). A storage unit (119) capable of storing the tray (102) and the paper discharge tray (103) is provided, and the paper feed tray (10) is provided for the storage unit (119).
2) and the paper discharge tray (103) are mounted so that they can be freely moved in and out, and the storage operation or the drawing operation is linked between the paper feed tray (102) and the paper discharge tray (103). It is characterized in that an interlocking mechanism (122) for making it intervenes is provided.

Further, a temporary fixing member (141) which is engaged and disengaged is arranged on at least one of the paper feeding tray (102) and the paper discharging tray (103), and the paper feeding is performed by the temporary fixing member (141). The tray (102) and the output tray (1
03) and at least one of them can be temporarily fixed at a position corresponding to the sheet material size.

[0034]

[Action]

<Operation of the First Invention> According to the present invention, the sheet material detecting means (26) includes the guide surface (23) of the side guide (23).
It is mounted in the immediate vicinity of c) and moves with the side guide (23). Therefore, when the sheet material detecting means (26) which detects the vicinity of the side edge of the sheet material (P) detects the sheet material (P) on the paper feed tray (12), the sheet material (P) side is detected. The side guides (23) are arranged in the vicinity of the edges, so that the sheet material (P) is guided by the guide surfaces (23) of the side guides (23) during sheet feeding.
By c), a good image is formed on the sheet material (P), which is restricted to a predetermined position and has no positional deviation. <Operation of the Second Invention> According to the present invention, the two systems of transport means are selectively used and are not used at the same time. Therefore, one switching member (69) is provided between the two transport means. The sheet material conveying path (59) and the guide means can be used respectively. <Operation of Third Invention> A third invention is directed to a paper feed tray (10
2) and the discharge tray (103) can be stored in the storage section (119) in the apparatus main body (101). And
At this time, the paper feed tray (102) and the paper discharge tray (10
When one of the trays of 3) is stored in the storage section (119), the other tray is stored in the storage section (119) in conjunction with this storage operation. When one tray is pulled out from the storage section (119), the other tray is pulled out from the storage section (119) in conjunction with the pulling-out operation. Therefore, the paper feed tray (102) and the paper discharge tray (103) can be stored and withdrawn by one-touch operation.

When one of the paper feed tray (102) and the paper discharge tray (103) is expanded / contracted (movement in the direction of storing in the storage portion), the other tray is interlocked with the expansion / contraction operation. And then expand and contract. Then, when one tray is temporarily fixed by the temporary fixing member (141) at a position corresponding to the sheet material size to be used, the other tray is also temporarily fixed at the sheet material (P) size position to be used. Thereby, the occupied area of the image forming apparatus can be changed according to the size of the sheet material (P) used, and when using the sheet material (P) of a small size, the image forming apparatus can be installed in a small space. It will be possible. Further, even when a small-sized sheet material (P) is used, since the paper feed tray (102) and the paper discharge tray (103) are sized according to the sheet material size, the sheet material (P) is taken out. Etc. are easy.

The reference numerals in the parentheses are for reference to the drawings and do not limit the configuration in any way.

[0037]

Embodiments of the present invention will be described below with reference to the drawings. <Embodiment 1 of the first invention> FIG.
3 is a top view showing an example applied to the image forming apparatus illustrated in FIG. The same components and functions as those shown in FIG. 7 are designated by the same reference numerals, and the description thereof will be omitted. The paper feed tray 12 shown in FIG. 1 is provided with left and right side guides 23, 23 that are movable in the left-right direction (arrow K2 direction). Both side surface guides 23, 23 are connected by an interlocking mechanism (not shown), and when one is moved inward, the other is moved inward by the same distance, and when one is moved outward, the other is moved out by the same amount. To move to. In addition, inside each side guide 23,
A guide surface 23c that contacts the side edge of the sheet material P and positions the sheet material P in the left-right direction (the direction perpendicular to the sheet material transport direction K1) is formed. Therefore, the sheet material P is set between the two and the one side guide 2
By lightly pushing one side edge of the sheet material P by the guide surface 23c of No. 3, the guide surface 23c of the other side guide 23 can push the other side edge of the sheet material P, and by both, the sheet material P When the sheet is sandwiched, the sheet material P is automatically set at the center in the transport direction (the center in the left-right direction of the paper feed tray 12).

Guide surfaces 2 of the left and right side guides 23, 23
The sheet material detection means 26 is attached to the inner side of the front side of 3c and 23c (on the side of the arrow K1 in the conveying direction). In FIG. 1, there are various known sheet material detecting means 26, but in this embodiment, a photo interrupter is used. Explaining with reference to FIG. 2, the detection lever 27 is rotatably supported by a side guide 23 at its center portion by a pin 29. The detection lever 27 rotates clockwise (in the direction of arrow R2) in the drawing when the lower end portion 27a thereof is pushed by the sheet material P, and the upper end portion 27b blocks the optical path of the photo interrupter 30 fixed to the side guide 23. The presence or absence of the sheet material P is detected. Note that the photo interrupter 3
Instead of 0, a micro switch may be used.

When the above-mentioned sheet material detecting means 26 is used and the detection lever 27 does not block the optical path of the photo interrupter 30, that is, when the sheet material P is not detected, the sheet feeding and image forming processes are stopped, while the detection lever 27 is stopped. When the sheet interrupts the optical path of the photo interrupter 30, it is considered that the sheet material P is set at a predetermined position via the left and right side guides 23, 23, and the sheet feeding from the sheet feeding tray 12 and the image forming process are possible. To do. As a result, the sheet material P that can be fed from the sheet feed tray 12 is limited to the sheet material P set at a predetermined position on the sheet feed tray 12.
For other members such as the photosensitive drum 2,
Since it is set at an appropriate position, the image of the original is transferred well, and unnecessary toner is not attached. <Embodiment 2 of the First Invention> FIG. 3 is a drawing well showing the features of the second embodiment, as viewed from the paper feed side of the apparatus main body 1. The sheet material detecting means 26 is composed of an LED 31 and a photo sensor 32, and fixes the LED 31 and the photo sensor 32 inside the left and right side guides 23, 23, respectively. Each LED 31 and photo sensor 3
The sheet material P on the sheet feeding tray 12 is arranged above and below the sheet material P, and the presence or absence of the sheet material P is detected by whether the sheet material P blocks or does not block the optical path formed between them. . In addition, it is assumed that a through hole is formed in the paper feed tray 12 at a position corresponding to the optical path of the LED 31.

In this embodiment, the sheet material is detected by using the LED 31 and the photo sensor 32, and is applied to an image forming apparatus using a transfer roller as a transfer electric field forming means.

Also in the present embodiment, when the sheet material detecting means 26 does not detect the sheet material P, the sheet material P is always placed on the sheet feeding tray 12 by not performing the sheet feeding and the image forming process. Since the sheet material P can be placed at a predetermined position, it is possible to feed and convey the sheet material P to a predetermined position of the transfer portion that transfers the toner image from the photosensitive drum 2 to the sheet material P. Further, the outside of the sheet material area is aligned with the opening area of the side surface guide 23, and L is placed on the photosensitive drum 2.
Since the toner was not developed by shining light on the ED array, contamination of the transfer roller could be prevented.
Further, since the sheet material can be detected without contact, it can be used for thin paper. <Third Embodiment of First Invention> In the first and second embodiments, the sheet material P is sent to the center of the conveying path, that is, so-called central paper feeding, but here, as shown in FIG. This is a method in which the sheet material side end is aligned with the end of the transport path and the sheet is fed.

In this case, one side guide 23a is fixed, and only the other side guide 23b is movable. Inside each side guide 23a, 23b,
Guide surface 23 for guiding the side edges of the sheet material P, respectively
c and 23d are formed. Also in this embodiment, the sheet material detecting means 26a and 26b fixed to the respective side guides 23a and 23b are provided, and if at least one of the sheet material detecting means 26a and 26b does not detect the sheet material P, the sheet feeding is determined. By not performing the image forming process, the sheet material P can be always placed at a predetermined position on the paper feed tray 12, and thus a predetermined transfer portion for transferring the toner image from the photosensitive drum 2 to the sheet material P can be set. It was possible to feed and convey the sheet material P to the position. <Embodiment 4 of the First Invention> The present invention can be effectively applied to an image forming apparatus having one or more cassettes and a manual feed tray even when paper is fed from the manual feed tray. As an example, a multicolor image forming apparatus as shown in FIG. 5 will be described.

The multicolor image forming apparatus, as shown in FIG.
An image carrier, which is rotatably supported and rotatable in the direction of the arrow, that is, the photosensitive drum 2, is disposed, and an image forming unit is disposed on the outer peripheral portion thereof. The image forming means may be any means, but in this example, the primary charging device 3 that uniformly charges the photosensitive drum 2 and the color-separated optical image or an optical image corresponding to the primary charging device 3 are irradiated to the photosensitive drum 2. And an exposure unit 33 that forms an electrostatic latent image on the photosensitive drum 2 and a rotary developing device 6 that develops and visualizes the electrostatic latent image on the photosensitive drum 2.

The rotary developing device 6 includes a yellow developer,
Four developing units 6Y and 6 for separately storing four color developers, that is, a magenta color developer, a cyan color developer, and a black color developer.
M, 6C, 6BK and these four developing devices 6Y, 6M,
It is composed of a substantially cylindrical housing 6d which holds 6C and 6BK and is rotatably supported. Rotary developing device 6
Rotates the housing 6d to convey a desired developing device to a position facing the outer peripheral surface of the photosensitive drum 2, and develops an electrostatic latent image on the photosensitive drum 2 to enable full-color development for four colors. It is configured.

The visible image on the photosensitive drum 2, that is, the toner image is transferred onto the sheet material P carried by the sheet material carrier 7a of the transfer device 7 and conveyed. In this example,
The sheet material carrier 7 is a transfer drum that is rotatably supported, and the transfer drum 7a includes cylinders 7b and 7c arranged at both ends and both cylinders 7b and 7c, as will be apparent from FIG. And a connecting member 7d for connecting 7c,
A sheet material carrying sheet 7e is stretched as a sheet material carrying member in the outer peripheral surface opening areas of the cylinders 7b and 7c. As the sheet supporting sheet 7e, a film-shaped dielectric sheet such as polyethylene terephthalate or polyvinylidene fluoride resin film is usually used. Transfer drum 7
The connecting member 7d is a sheet material P fed from the sheet feeding device.
Has a sheet material gripper 7f for gripping. Further, as shown in FIG. 5, a transfer charger 7g, and an inner charge eliminator 35 and outer charge eliminators 36 and 37 which constitute a charge eliminator are arranged inside and outside the transfer drum 7a.

The process of forming a full-color image by the multicolor electrophotographic copying apparatus having the above-mentioned structure will be briefly described as follows.

The photosensitive drum 2 is uniformly charged by the primary charger 3, and the exposure means 33 causes an optical image E corresponding to image information.
To form an electrostatic latent image on the photosensitive drum 2. The electrostatic latent image is developed and visualized by the rotary developing device 6. That is, a toner image is obtained on the photosensitive drum 2 by using a resin as a base material and a toner having an average particle diameter of 8 to 10 μm, for example.

On the other hand, the sheet material P is a pair of registration rollers 19
Is sent to the transfer drum 7a through the paper feed guide 39 in synchronization with the toner image on the photosensitive drum 2, and the gripper 7f
The leading end of the transfer drum 7a is gripped by, for example, and conveyed in the same direction as the transfer drum 7a rotates in the direction of the arrow R3 in the figure.

Next, in the image transfer area in contact with the photosensitive drum 2, the sheet material carrying sheet of the transfer drum 7a,
That is, the toner image on the photosensitive drum 2 is transferred onto the sheet material P by receiving a corona discharge having a polarity opposite to that of the toner from the back surface of the dielectric sheet 7e by the transfer charger 7g.

After the transfer process of the toner image of each color is performed on the sheet material P, the transfer drum 7a is operated by the action of the separation claw 40 while being discharged by the discharging chargers 35, 36 and 37.
The sheet is separated from the sheet and conveyed to the fixing device 42 by the conveying belt 41. Then, after the toner image is fixed by heat in the fixing device 42 to form a permanent image, the toner image is discharged outside the copying machine.

On the other hand, the photosensitive drum 2 is subjected to the image forming process again after the residual toner on the surface is cleaned by the cleaner 9. Similarly, the surface of the dielectric sheet 7e of the transfer drum 7a is also a cleaning device 45 including a fur brush or the like.
After being cleaned by the cleaning assisting means 46, it is again subjected to the image forming process.

The present invention can be applied to the manual feed tray (paper feed tray) 12 of the multicolor image forming apparatus described above. That is, as described in Embodiment 1 with reference to FIG. 1, the sheet material P on the manual feed tray 12 is guided, and the sheet material P side of the movable side guide 23 is fixed to the side guide 23. The detection means 26 is provided.
When the sheet material detecting unit 26 does not detect the sheet material P, the sheet material P can be always placed at a predetermined position on the sheet feeding tray 12 by not performing the sheet feeding and the image forming process. It was possible to feed and convey the sheet material P to a predetermined position of the transfer component that transfers the toner image from the photosensitive drum 2 to the sheet material P.

In particular, when a multicolor image is to be obtained by superimposing images of four colors as in this embodiment, if the sheet material width is smaller than the image forming width, the sheet material carrying sheet 7e. Since the four color toner images are transferred on top,
Not only the toner is wasted, but also the sheet material carrying sheet 7
It becomes difficult to clean e. As a result, there arises a problem that the back of the paper becomes dirty during the subsequent image formation, but it can be prevented by applying the present invention.

Further, as the sheet material detecting means 26, the photo interrupter 30 or the microswitch described with reference to FIG. 2 may be used, or L as described in the second embodiment.
The ED 31 and the photo sensor 32 may be arranged and used as shown in FIG. <Embodiment 1 of the second invention> FIGS. 15 and 16 show Embodiment 1 of the second invention.

As shown in the sectional view of the embodiment of FIG.
In an image forming apparatus or the like provided with a U-shaped reversing path 59 as a sheet material conveying path, the sheet material P sent by the sheet feeding roller 57 is formed between the outer guide 59b and the inner guide 59a of the outer guide member (switching member) 69. The sheet is conveyed while hitting the outer guide member 69 in the space, and proceeds to the pair of conveying rollers 61. On the other hand, the sheet material P inserted through the manual sheet feeding port (sheet material insertion port) 65 hits the pair of transport rollers 61. By a sensor (not shown) provided between the paper feed port 65 and the conveyance roller pair 61, the manual paper feed port 65 is inserted.
Then, the insertion of the sheet material P is detected, and the pair of transport rollers 61 starts to rotate. As a result, the sheet material P is sent to the image forming section 52 via the pair of registration rollers 63.

Normally, when the sheet is conveyed through the U-shaped reversing path 59 and jammed when the sheet material P is jammed, the outer guide member 69 is opened to an angle as shown in FIG. As a result, the jammed paper sandwiched between the U-shaped inversion paths 59 can be pulled out. The guide protrusion 69a is caught on a part of the support portion 59c on the main body side so that it cannot be opened beyond a certain angle.

When inserting paper from the manual feed guide,
By pulling down the outer guide member 69 in the direction of arrow A, the guide protrusion 69a passes through the groove of the support portion 59c,
It is possible to move to the position (first position) shown in FIG. The back surface of the outer guide member 69, which has a substantially flat shape, is set at the entrance of the manual feed port 65, and serves as a guide for the sheet material P for manual feeding. At this time, the outer guide member 69 is biased by the spring 75 to stably maintain the horizontal state.

Assuming that the cassette 5 is again in the state shown in FIG.
When performing U-turn sheet feeding from 1, the outer guide member 69 is pulled downward again, the hinge 70 moves to the lower side of the elongated hole 71, and the guide protrusion 69a enters into the groove of the support portion 59c.
The outer guide member 69 is returned to the position (first position) shown in FIG.

As described above, by selectively moving the position of the outer guide member 69 between the first position and the second position as necessary, the manual feed can be performed without providing a new guide. When feeding paper from the paper feed port 65, the guide can be performed by a part of the outer guide member,
A smooth manual feed could be achieved without providing unnecessary parts. Further, even when the manual paper feed port 65 is not used, it is possible to omit troublesome work such as storing and folding the guide. <Embodiment 2 of the second invention> Embodiment 2 shown in Figs.
The cross-sectional view of is shown.

The outer guide member 69, which is a part of the U-turn guide, can be rotated by the hinge 72, and the usual jam processing of the U-turn portion is performed as shown in FIG. At the hinge 72, the outer guide member 69 is removable, and as shown in FIG. 20, the removed outer guide member 69 is removed.
The tip of the is attached to the main body attaching portion 73 by a magnet by suction or press-fitting so that it can be used as a manual insertion guide. According to this method, there is only one simple part, and there are almost no additional parts on the main body side, and the U-turn guide and the manual feed guide can be used in common with a simple structure, resulting in cost reduction. <Third Embodiment of Second Invention> FIGS. 21 and 22 show a third embodiment.

The portion forming the U-turn guide of the outer guide member 69 of the mounting method as shown in the second embodiment is the movable portion 69b. As shown in FIG. 22, if the U-turn portion is used as a guide surface and the movable portion 69b of the U-turn portion is moved to a position where it does not interfere with the sheet, smooth sheet feeding can be obtained, and side guides for the manual feed sheet can be obtained. Can also play the role of. As a result, a manual paper feed mechanism that is even more convenient to use can be obtained.

Also, as shown in FIG. 23, even if a multi-feeding mechanism having a paper feed roller 76, a lower guide 77, etc. is provided in the manual feed section, the U-turn guide section is used as the tray thereof as described above. It's easy as an example. Further, by providing a sensor that switches between cassette paper feeding and manual paper feeding in association with the opening / closing of the outer guide member 69, the paper feeding method can be switched without selecting the paper feeding method in the operation unit. Even if this is not a sensor, even if the drive system is switched, it is possible to easily switch the paper feeding method by opening and closing the outer guide member 69. An example of switching the sensor or switching the drive is shown in FIGS.

The switch 80 with respect to the fixed contact 81
Are swingably mounted by a fulcrum 79. Axis 6
At the tip of the outer guide member 69 that can be opened and closed via 0,
An engaging portion 78 that engages and disengages is formed at one end of the switch 80. When the outer guide member 69 is closed (FIG. 25),
The engaging portion 78 engages with the switch 80, and the switch 80 separates from the contact 81. At this time, the sheet material P is fed from the cassette 51 by the feed roller 57. On the other hand, when the outer guide member 69 is released (FIG. 26) and the back surface that serves as the paper feed guide is made substantially horizontal, the engagement between the engaging portion 78 and the switch 80 is released, whereby the switch 80 contacts. , And switches the paper feed method from cassette paper feed to manual paper feed.

FIG. 27 mechanically performs the above switching. A switching portion 69c is provided at the tip of the outer guide member 69.
To form. Further, the roller pair 8 is connected by the connecting member 82.
3, 83 are supported, and the roller pair 86, 86 is supported by another connecting member 85. Both connecting members 82 and 85 are engaged with and disengaged from the switching portion 69c of the outer guide member 69, and
It is mounted so that it can swing in the direction of the arrow. When the outer guide member 69 is released (solid line in FIG. 27), the switching portion 69c becomes
The connection member 85 is engaged, the roller 83 on the connection member 82 side is engaged with the paper feed roller pair 61, and the paper feed method is set to the manual paper feed side, and conversely, the outer guide member 69 is closed (the same). (Dotted line in the figure) It is switched to the cassette sheet feeding side via the roller pair 86. <Embodiment 1 of the third invention> FIG. 28 shows Embodiment 1 of the invention.
2 shows the overall configuration of the image forming apparatus (copier) according to FIG.
Reference numeral 9 shows a configuration of a main part of the image forming apparatus.

In this image forming apparatus, the same members as those of the above-mentioned conventional image forming apparatus are designated by the same reference numerals, and the description of those which are functionally and structurally the same will be omitted. Hereinafter, the same applies to Examples 2, 3, 4, 5, and 6.

In this image forming apparatus, the paper feed tray 10
2 and the discharge tray 103 are integrally formed,
It has a size capable of stacking the maximum size sheet material used in the image forming apparatus. And this paper feed tray 1
02 and the discharge tray 103 are the image forming apparatus main body 101.
On the other hand, it is attached so as to be movable in the sheet material conveying direction (arrow A and B directions).

Paper feed tray 102 and paper discharge tray 103
Is movably held by upper and lower guides 117A and 117B formed on the paper feed side and the paper discharge side of the image forming apparatus main body 101, respectively.
By sliding the sheet material in the sheet material conveying direction, the sheet can be stored in the storage portion 119 provided in the image forming apparatus main body 101 (at this time, the outer end surface of the tray is the side surfaces 101A and 101B of the image forming apparatus main body 101 On the same plane),
Further, it can be pulled out from the storage section 119 to the outside of the machine. That is, the paper feed tray 102 and the paper discharge tray 103 are
It is installed so that it can move in and out freely.

As shown in FIG. 29, in the apparatus main body 101, an endless belt (interlocking mechanism) rotatably wound around pulleys 120 and 121 arranged at guide 117B on the paper feed side and the guide 117B on the paper discharge side. ) 122 is installed horizontally.

The inner ends of the paper feed tray 102 and the paper discharge tray 103 are connected to the endless belt 22 via connecting members 123 and 125, respectively. The connecting members 123 and 125 are in the shape of a geta, and the upper and lower tooth portions 126A and 126B are formed.
The groove formed on the upper end portion 122A and the lower end portion 122B of the endless belt 122 is fitted in the groove. Each tooth 1
The grooves formed in 26A and 126B are set to a size that allows the belt 122 to slide. The grooves of the tooth portions 126A and 126B of the connecting members 123 and 125 are fitted into the upper portion 122A and the lower portion 122B of the endless belt 122 in order to enhance the attachment stability to the endless belt 122.

Connecting member 12 for connecting the paper feed trays 102
3, the upper tooth portion 126A is fixed to the upper portion 122A of the endless belt 122 with a screw 127, and the connecting member 125 that connects the paper ejection tray 103 has the lower tooth portion 126B connected to the lower portion 122B of the endless belt 122. It is fixed with a screw 127.

Connection shafts 129 and 130 are provided at the inner ends of the paper feed tray 102 and the paper discharge tray 103. The connection shafts 129 and 130 are connected to the endless belt 122 by connecting members 123 and 125. Oval holes 123A, 12
5A is rotatably fitted, and the paper feed tray 102 and the paper discharge tray 103 are connected to the endless belt 122 via connecting members 123 and 125.

In this way, the paper feed tray 102 attached to the opposite side surfaces 101A and 101B of the apparatus main body 101.
When the image forming apparatus is stored in a predetermined storage location, the sheet discharge tray 103 can be stored in the storage section 119 in the apparatus main body 101. When performing this storage, one of the trays is stored in the apparatus main body. When it is pushed into 101, the other tray is interlocked by the endless belt 122 and the apparatus main body 1
It will come into 01.

Therefore, when the paper feed tray 102 and the paper discharge tray 103 are stored in the storage unit 119 in the apparatus main body 101 or when the paper storage tray 119 is pulled out from the storage unit 119, only one of the trays is pushed in, and the paper feed tray 102 and the paper discharge tray Both of the paper trays 103 can be stored at the same time, and both the paper feed tray 102 and the paper discharge tray 103 can be pulled out at the same time only by pulling out one tray. The paper feed tray 102 and the paper discharge tray 103 are interlocked with the storage direction and the withdrawal direction because when the endless belt 122 is rotated, the upper portion 122A and the lower portion 122B thereof move in opposite directions. <Embodiment 2 of the third invention> FIG. 30 shows a main structure of an image forming apparatus according to Embodiment 2 of the present invention.

This image forming apparatus is obtained by partially modifying the configuration of the image forming apparatus of the first embodiment.

In this image forming apparatus, the endless belt 1
22 is wound around the pulleys 120 and 121 in a figure 8 shape (placing), and the pulleys 120 and 12 are wound together.
Gears (pinions) 120A and 121A are integrally provided on one side of the rack 1, and racks 102A and 103A formed on the lower surfaces of the paper feed tray 102 and the paper discharge tray 103 are engaged with the gears 120A and 121A. There is.

In this structure, the gears 120A and 121A meshed with the racks 102A and 103A of the paper feed tray 102 and the paper discharge tray 103 rotate in opposite directions, so that the paper feed tray 102 and the paper discharge tray 103 are rotated. Is linked to the storage direction and the withdrawal direction. <Embodiment 3 of the Third Invention> FIG. 31 shows a main structure of an image forming apparatus according to Embodiment 3 of the present invention.

In this image forming apparatus, the paper feed tray 1
02 and the paper ejection tray 103 are attached to both ends of a cross link (interlocking mechanism) 132 rotatably attached to a main body 101 (not shown) around a central support shaft 131, and shafts (connecting pins) 133. It is connected through 135. In this case, the shafts 133 and 135 are slidably fitted in the oval holes 132A and 132B at the ends of the cross link 132.

In the case of this structure, when one of the paper feed tray 102 and the paper discharge tray 103 is pushed in as shown in the phantom line, the other tray is pulled in by the cross link 132, and either tray is pulled out. Since the other tray is pushed out by the cross link 132,
The paper feed tray 102 and the paper discharge tray 103 are interlocked with the storage direction and the withdrawal direction. <Embodiment 4 of Third Invention> FIG. 32 shows a main structure of an image forming apparatus according to Embodiment 4 of the present invention.

This image forming apparatus is obtained by adding a part of the configuration to the image forming apparatus of the first embodiment.

In this image forming apparatus, the paper feed tray 1
A plurality of V-shaped click grooves 136, 137, 139, 1 corresponding to the size of the sheet material to be used on one end surface of 02.
40, and a stopper portion (temporary fixing member) 141 that can be engaged with and disengaged from the click grooves 136, 137, 139, 140 is provided on the apparatus body 101 (not shown) side.

The stopper portion 141 has a springy structure and is provided with a plate-shaped operation knob 141A and a triangular engagement claw 141B.

Since the paper feed tray 102 can be expanded and contracted in the sheet material conveying direction, the paper supply tray 102 is expanded and contracted according to the size of the sheet material to be used, and the click grooves 136 corresponding to the size of the sheet material. 137, 139,
The stopper portion 141 is attached to the 140 by using the operation knob 141A.
When the engaging claw 141B of is engaged, the paper feed tray 102
Is the same size (length) as the size of the sheet material used
become.

The paper discharge tray 103 is the paper feed tray 1
Since the paper sheet 102 is expanded / contracted in association with the expansion / contraction movement of 02, the discharge tray 103 is also approximately the same size as the sheet material size to be used at the same time.

In the illustrated example, when the engaging claw 141B of the stopper 141 is engaged with the click groove 137, the paper feed tray 102 (and the paper discharge tray 103) becomes a postcard size.
When the engaging claw 141B is engaged with the click groove 139, the paper feed tray 102 is set to B5 size, and when the engaging claw 141B is engaged with the click groove 141, the paper feed tray 102 is set to the maximum size. There is.

Further, the paper feed tray 102 is replaced with the apparatus main body 101.
When the image forming apparatus is carried, the paper feed tray 102 can be prevented from popping out of the apparatus main body 101 by engaging the engaging claw 141B with the click groove 136 when the image forming apparatus is accommodated in the accommodation section 119 (not shown). It is like this.

In the image forming apparatus having the above-described structure, it is possible to change the sheet tray 102 and the sheet discharge tray 103 to the size of the sheet material to be used by expanding and contracting one of the trays. So
When a sheet material other than the maximum size sheet material is used, the occupied area of the image forming apparatus can be changed according to the size of the sheet material used, and the image forming apparatus can be installed in a small space.

Although the click grooves 136, 137, 139, 140 are provided on the side of the paper feed tray 102 here,
It may be provided on the paper ejection tray side. <Fifth Embodiment of the Third Invention> FIG. 33 shows a main structure of an image forming apparatus according to a fifth embodiment of the present invention.

This image forming apparatus is obtained by partially changing the configuration of the image forming apparatus of the fourth embodiment. Here, the click grooves 136 and 137 are formed on the lower surface of the paper feed tray 102 (or the paper discharge tray 103). , 139, 140 are provided. <Embodiment 6 of the Third Invention> FIGS. 34 and 35 show the main configuration of an image forming apparatus according to Embodiment 6 of the present invention.

In this image forming apparatus, the paper feed tray 10
2 and the discharge tray 103 are hollow fixed tray portions 142A and 143A and a flat movable tray portion 142, respectively.
B and 143B. Fixed tray section 142
A and 143A are side surfaces 101A and 101A of the apparatus main body 101.
It is attached to B by support shafts 145 and 146 so as to be vertically rotatable. In addition, the movable tray portions 142B, 14
3B is fitted in the fixed tray portions 142A and 143A so as to be able to extend and contract.

Gears 147 and 149 are horizontally installed at the front and rear ends on one side in the fixed trays 142A and 143A, respectively. Pulleys 147A and 149A are integrally formed on the upper surfaces of these gears 147 and 149. Then, the gears 147, 149 have their respective pulleys 147A, 1
They are connected by an endless belt 150 wound around 49A.

Racks 151A and 151B are formed on one side of the movable tray sections 142B and 143B fitted in the fixed tray sections 142A and 143A, respectively.
51A and 151B mesh with the respective gears 149 and 149 on the rear end side.

Each fixed tray unit 1 is provided in the apparatus main body 101.
Gears 152 and 153 that mesh with gears 147 and 147 on the front end side of 42A and 143A are installed. Pulleys 152A and 153A are integrally formed on the upper surfaces of the gears 152 and 153. Then, each gear 152, 15
3 is connected to the pulleys 152A and 153A by an endless belt 155 that is wound (raised) in a figure 8 shape.

In this embodiment, each fixed tray portion 142
The gears 147 and 149 provided on the A and 143A, the endless belt 150 that connects them, the gears 152 and 153 that are provided on the apparatus main body 101, and the endless belt 155 that connects them are the movable tray portion 142B of the paper feed tray 102. And a movable tray portion 143B of the paper discharge tray 103 are interlocked with each other.

Now, the movable tray portion 1 of the paper feed tray 102
When 42B is pushed into the fixed tray portion 142A (reduction movement), the gear 149 on the rear end side that meshes with the rack 151A.
Rotates clockwise, and this rotation is transmitted to the gear 147 on the front end side via the endless belt 150.

The rotation of the gear 147 is transmitted to the gear 152 in the apparatus main body 101, and the rotation of the gear 152 is transmitted to the gear 153 via the endless belt 155.

The rotation of the gear 153 is transmitted to the gear 147 on the front end side of the fixed tray portion 143A of the discharge tray 103,
The rotation of the gear 147 is transmitted to the gear 149 on the rear end side via the endless belt 150. At this time, the gear 149 rotates counterclockwise, which causes the movable tray portion 143B of the paper discharge tray 103 to move.
The same amount of interlocking movement with the movable tray portion 142B enters into the fixed tray portion 143A (reduction movement).

At this time, the endless belt 150 on the paper feed tray 102 side and the endless belt 155 on the apparatus main body 101 side.
The arrow indicates the rotation direction of the endless belt 150 on the side of the discharge tray 103.

On the other hand, the movable tray section 1 of the paper feed tray 102
When 42B is pulled out from the fixed tray portion 142A (extension movement), the gear 149 of the fixed tray portion 142A rotates counterclockwise, while the gear 149 of the fixed tray portion 143A of the paper discharge tray 103 rotates clockwise. Therefore, the movable tray portion 143B of the paper discharge tray 103 is interlocked with the movable tray portion 142B of the paper feed tray 102 and moves out from the fixed tray portion 143A by the same amount (extension movement).

The movable tray portion 1 of the paper discharge tray 103
Similarly, when 43B is expanded / contracted, the paper feed tray unit 1 is also used.
The movable tray part 142B of No. 02 is expanded and contracted together.

Movable tray portion 142B of paper feed tray 102
On the other side, a plurality of V-shaped click grooves 156, 157, 159, 160 corresponding to the size of the sheet material to be used are formed.

Further, the fixed tray section 1 of the paper feed tray 102.
42A includes the click grooves 15 of the movable tray portion 142B.
A stopper portion (temporary fixing member) 162 that can be engaged and disengaged with 6, 157, 159 and 160 is integrally formed.

The stopper portion 162 has a springy structure, and is provided with a plate-like operation knob 162A and a triangular engaging claw 162B.

Also in the case of this image forming apparatus, similarly to the image forming apparatus of the fourth embodiment, the movable tray portion 142B of the paper feed tray 102 is expanded / contracted so that the engaging claw 162B of the stopper portion 162 is fitted in the click groove 157. When engaged, the paper feed tray 102 (and the paper discharge tray 103) becomes a postcard size,
When the engaging claw 162B is engaged with the click groove 159, the sheet feeding tray 102 has a B5 size, and when the engaging claw 162B is engaged with the click groove 160, the sheet feeding tray 102 has a maximum size. Then, the engaging claw 16 is inserted into the click groove 156.
By engaging 2B, it is possible to prevent the movable tray portion 142B stored in the fixed tray portion 142A from protruding.

FIG. 34 shows a case where the movable tray portions 142B and 143B of the paper feed tray 102 and the paper discharge tray 103 are set to the maximum size. Further, the imaginary line shows the case where the postcard size is set. In the case of the image forming apparatus, when the image forming apparatus is stored in the storage place, the paper feed tray 102 and the paper discharge tray 103 are stored.
Is the support shaft 14 of the fixed tray portions 142A and 143A.
5 and 146 are rotated upward to fold the side surfaces 101A and 101B of the apparatus main body 101.

[0105]

【The invention's effect】

<Effects of the First Invention> As described above, according to the first invention, the movable side guide for guiding the sheet material on the paper feed tray, and the sheet material detection arranged inside the guide surface of the side guide are provided. Means for feeding the sheet material from the sheet feed tray only when the sheet material detection means detects the sheet material, so that the fed sheet material is always in a predetermined position via the side guide. Since it is guaranteed that they are set, for example, the relative positional relationship between the original, the photosensitive drum, the sheet material, etc. is accurately maintained, and the toner image transferred from the photosensitive drum to the sheet material is set at a suitable position on the sheet material. Can be transcribed. That is, it is possible to effectively prevent a part of the image of the original from being transferred to the sheet material, or the excess toner being transferred to the sheet material. <Effect of the Second Invention> According to the second invention, the movable switching member is moved between the first position and the second position so that the sheet material conveying path of one of the sheet feeding means is moved. Since it can be used as a part of the paper, or as a paper feed guide for other paper feeding means,
The number of parts is reduced to simplify the overall structure and prevent the paper feed guide from obstructing when not needed. <Effect of the third invention> Further, according to the third invention, a storage section for storing the paper feed tray and the paper discharge tray is provided in the apparatus main body, and an interlocking mechanism for interlocking the movement of these trays is provided between both trays. By loading these trays according to the size of the sheet material to be used, the occupied area can be reduced, and the other tray can be automatically moved by simply moving one tray. it can.

[Brief description of drawings]

FIG. 1 is a plan view of the vicinity of a paper feed tray according to a first embodiment of the first invention.

FIG. 2 is a vertical sectional view showing the operation of the sheet material detecting means.

FIG. 3 is a front view of the sheet material detection unit according to the second embodiment.

FIG. 4 is a plan view of the sheet material detection unit of the third embodiment.

FIG. 5 is a vertical sectional view of the image forming apparatus according to the fourth embodiment.

FIG. 6 is a perspective view showing a structure of a transfer drum of the same.

FIG. 7 is a vertical sectional view of a conventional image forming apparatus.

FIG. 8 is a perspective view showing the positional relationship between the photosensitive drum and the sheet material.

FIG. 9 is a perspective view of a conventional paper feed tray.

FIG. 10 is a perspective view showing the positional relationship between the photosensitive drum and the sheet material.

FIG. 11 is a vertical cross-sectional view of another conventional image forming apparatus.

FIG. 12 is a perspective view showing the positional relationship between the photosensitive drum and the sheet material.

FIG. 13 is a perspective view showing the positional relationship between the photosensitive drum and the sheet material.

FIG. 14 is a perspective view showing the positional relationship between the photosensitive drum and the sheet material.

FIG. 15 is a vertical cross-sectional view showing a switching member according to Embodiment 1 of the second invention.

16 is an explanatory diagram of the operation of FIG.

FIG. 17 is an operation explanatory diagram of the same as FIG.

FIG. 18 is a vertical sectional view showing a switching member according to the second embodiment.

FIG. 19 is an explanatory diagram of the operation of FIG.

FIG. 20 is an operation explanatory diagram of FIG.

FIG. 21 is a vertical sectional view showing a switching member of Example 3 of the same.

FIG. 22 is an explanatory diagram of the operation of FIG.

FIG. 23 is an operation explanatory diagram of another embodiment of the present invention.

FIG. 24 is a vertical cross-sectional view of a conventional paper feeding unit.

FIG. 25 is an operation explanatory view when the drive is switched by the switching member.

FIG. 26 is an operation explanatory view when switching the drive by the switching member.

FIG. 27 is an operation explanatory view when switching the drive by the switching member.

FIG. 28 is a vertical cross-sectional view of the image forming apparatus according to the first embodiment of the third invention.

FIG. 29 is an enlarged perspective view showing the structure of the coupling mechanism.

FIG. 30 is a perspective view showing the structure of the coupling mechanism of the second embodiment.

FIG. 31 is a plan view showing the structure of the coupling mechanism of the third embodiment.

FIG. 32 is a perspective view showing the structure of a temporary fixing member according to the fourth embodiment.

FIG. 33 is a vertical cross-sectional view showing the structure of the paper feed tray according to the fifth embodiment.

FIG. 34 is a plan view showing the structure of the coupling mechanism of the sixth embodiment.

FIG. 35 is a vertical cross-sectional view showing the structure of the paper feed tray.

FIG. 36 is a vertical sectional view showing a conventional image forming apparatus.

[Explanation of symbols]

 12 Paper Feed Tray 23 Side Guide 23c Guide Surface 26 Sheet Material Detecting Means 59 Sheet Material Conveying Path (U-shaped Reverse Path) 65 Sheet Material Inserting Port (Manual Feeding Port) 69 Switching Member (Outer Guide Member) 101 Device Main Body 101A Side Surface 101B Side surface 102 Paper feed tray 103 Paper discharge tray 119 Storage section 122 Interlocking mechanism (endless belt) 141 Temporary fixing member (stopper section) K1 Conveying direction P Sheet material

Claims (4)

[Claims] 1. A side guide, which is movable in a direction intersecting the sheet material conveying direction, is provided on a paper feed tray, and a side surface of the sheet material is regulated from the outside by a guide surface of the side guide. In an image forming apparatus including a sheet feeding device that positions a sheet material in the left-right direction, a sheet that is movable on the guide surface of the side guide together with the side guide and that can detect the vicinity of the side edge of the sheet material. Image forming, characterized in that a material detecting means is provided, and paper can be fed from the paper feeding tray only when the sheet material detecting means detects the sheet material regulated by the side guides. apparatus. 2. A sheet material feeding device having at least two systems of sheet feeding means, and a sheet material conveying path of one sheet feeding means and a sheet material insertion port of the other sheet feeding means are provided in proximity to each other. In an image forming apparatus including: a sheet material conveying path, a first position that forms a part of the sheet material conveying path and a second position that guides a sheet material fed from the sheet material insertion port are selectively moved. An image forming apparatus having a switchable member. 3. An image forming apparatus in which a paper feed tray and a paper discharge tray are arranged on opposite sides of the apparatus main body, wherein the paper feed tray and the paper discharge tray are provided in the apparatus main body. Is provided, and the paper feed tray and the paper discharge tray can be attached to and removed from the paper storage unit, and the respective storage operations can be performed between the paper feed tray and the paper discharge tray. An image forming apparatus comprising an interlocking mechanism for interlocking or interlocking withdrawal operation. 4. A temporary fixing member that engages and disengages is disposed on at least one of the paper feeding tray and the paper discharging tray, and at least one of the paper feeding tray and the paper discharging tray is a sheet by the temporary fixing member. The image forming apparatus according to claim 3, wherein the image forming apparatus is temporarily fixed at a position corresponding to a material size.