JP2000016601A - Paper feeder cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of an entire paper feeder cassette adapted to store arbitrary sizes of paper sheets therein without being influenced by a movable restriction plate regulating the edges of paper sheets when the cassette stores paper sheets of the maximum size. SOLUTION: A movable back end restriction plate 42 is provided turnably about a rotation axis 44 on a bottom plate 40a of a casing 40 storing paper sheets to constitute a paper feeder cassette 23. This movable back end restriction plate 42 is stored in a recess 40b formed on the bottom plate 40a, and is erected vertically on the face of the bottom plate 40a to regulate the back end of paper sheets for storing paper sheets of a small size. The restriction plate is turned to store in the recess 40b when it is not necessary. In this state, one of side walls of the casing is adapted as a back end restriction plate 41 to eliminate a redundant space, and to reduce the size of the entire paper feeder cassette 23.

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 for forming a visible image corresponding to image data on a sheet and outputting the image on the sheet. And a paper feed cassette provided for feeding one sheet at a time.

[0002]

2. Description of the Related Art In an image forming apparatus, for example, an image forming apparatus using an electrophotographic system, a visible toner image is formed on a photosensitive member as a recording medium, and the toner image is formed on a sheet such as plain paper. In order to transfer and hold the toner image on the sheet as a permanent image on the sheet, the toner is fixed by, for example, passing through a heat fixing device, and then discharged outside the apparatus main body.

According to such an image forming apparatus, a sheet is conveyed to an image forming position in order to form a desired image on the sheet. Therefore, a sheet cassette or tray for storing or stacking sheets is provided, and sheets are fed from the sheet tray to the image forming position one by one. Then, the sheet on which the image has been formed is discharged from the image forming apparatus main body. In order to receive the discharged sheet, the discharge tray is provided so as to be exposed outside from the image forming apparatus main body. This is to make it easier for the user to remove the discharged image-formed sheet.

For example, as shown in FIG.
Reference numeral 0 designates a mounting plate 52 for mounting a sheet in a housing 51 having one open surface for accommodating the sheet, and supporting the mounting plate 52 on the side opposite to the front end in the sheet feeding direction. 52 and housing 51
The mounting plate 52 is floated upward by a spring (not shown) interposed between the mounting plate 52 and the bottom surface of the mounting plate 52. A separation claw 53 is provided to regulate the floating of the mounting plate 52 in accordance with the front end in the sheet feeding direction and to determine the uppermost position of the sheet mounted on the mounting plate 52. The separation claw 53 is rotatably supported, so that the rotation of the separation claw 53 by a predetermined amount or more is restricted.

A rear end regulating plate 54 and a width regulating plate 55 for regulating the sheet side edge are arranged along the slide mechanisms 56 and 57 so as to match the size of the sheets accommodated in the housing 51 of the sheet cassette 50. It is provided movably.
Therefore, the sheet can be placed on the placing plate 52 by moving the rear end and width regulating plates 54 and 55. Thereby, both sides of the sheet to be fed are one width regulating plate 55,
The sheet is regulated by the side plate 51a formed by one side wall of the housing 51, and is accurately guided and fed.

Further, the rear end of the sheet placed on the rear end regulating plate 54 is regulated, and at the same time, the front end of the sheet is
Are aligned with the front end face 51b. In this state, the separation claw 53 rides on its uppermost sheet on its own weight.

[0007] By detecting at least the position of the rear end regulating plate 54 by using a detection sensor provided on the image forming apparatus main body side, the size of the sheet accommodated in the sheet cassette 50 can be determined. Has become.

[0008]

As described above, the image forming apparatus is provided with a sheet feeding cassette for feeding one sheet in order to feed a sheet to a target position, that is, an image forming position. . This paper cassette is used to fill sheets,
In order to carry out the storage, the user usually detaches the image forming apparatus from the image forming apparatus while pulling it out, for example.

However, as shown in FIG. 5, when the size of the sheets to be accommodated in the sheet cassette 50 is changed, the regulating plates 54 and 55 are provided so as to be movable by a slide mechanism. The control plates 54 and 55 are provided so as to surround the periphery. For this reason, it is formed including a region larger than the position of the regulating plate 54 that regulates the rear end of the sheet of the maximum size.

In addition, the image forming apparatus main body also requires a space for accommodating the paper feed cassette 50 including its housing 51, that is, a space, so that the size of the paper feed cassette 50 becomes large, and the entire image forming apparatus main body also becomes large. Become larger.

Further, according to Japanese Patent Application Laid-Open No. Hei 9-110191, in the sheet cassette 50 shown in FIG.
And the like are provided so as to be slidable with respect to all the rotatably provided housings so that the size of the housing 51 can be reduced when a small-sized sheet is stored. However, even in such a configuration, when a sheet of the maximum size is stored, the rear 5
8 can be accommodated in the drawer housing 51.
For this reason, on the image forming apparatus side, it is necessary to previously set a space in which the sheets can be mounted in a state where at least sheets of the maximum size are stored in the sheet feeding cassette 50, and in any case, the image forming apparatus becomes large.

In addition, since the rear end regulating plate 54 must be slidably provided in the housing, the housing 51 itself needs to be one size larger than the maximum size sheet. Therefore, the sheet cassette for accommodating the largest size sheet has the same size as before.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention regulates at least the rear end of a sheet housing housing capable of accommodating a sheet of a maximum size that can accommodate a sheet of a smaller size. An object of the present invention is to provide a paper feed cassette that can be used.

In the present invention, the paper feed cassette will be described. However, the present invention is also applicable to a paper feed tray provided for regulating the rear end of a sheet and feeding paper. explain.

[0015]

According to the first aspect of the present invention, there is provided a sheet cassette for accommodating a desired size, wherein the sheet cassette accommodates a desired size. In a paper feed cassette which is provided with a regulating plate for regulating one end edge and capable of accommodating sheets of any size, a movable regulation for rotatably regulating one edge of the sheet is provided on a bottom plate of a housing accommodating the sheet. A plate is provided, and one side wall of the housing corresponding to the movable control plate is used as a control plate for controlling one end edge of the sheet in a state where the control plate is rotated to the non-control position and is accommodated in the bottom plate. It is characterized in that it can be configured.

According to such a configuration, one end edge of the sheet of the maximum size that can be accommodated in the sheet feeding cassette can be regulated by using one side wall of the housing constituting the cassette. Therefore, since the movable regulating plate does not need to be used to regulate the sheet of the maximum size, the housing itself may be formed according to the sheet of the maximum size, and the cassette itself is determined by the size of the sheet of the maximum accommodation size. . Therefore, the paper feed cassette itself can be made smaller as compared with the conventional one. Thus, the space for mounting the sheet cassette mounted on the image forming apparatus can be reduced, and the size of the image forming apparatus can be reduced accordingly.

Since the movable regulating plate is rotated and accommodated in the bottom plate of the housing constituting the sheet cassette, the movable regulating plate is not lost.

According to the second aspect of the present invention, the movable regulating plate is provided on a slide member slidably provided on a bottom plate of the housing. It is characterized in that it is provided so as to be rotatable with respect to it. According to this configuration, a sheet of an arbitrary size smaller than the maximum size sheet that can be accommodated in the sheet cassette can be accommodated. In this case, if the movable regulating plate is rotated and accommodated in the slide member side, no useless space is required, and the space of the slide member can be effectively used.

According to a third aspect of the present invention, there is provided a sheet feeding cassette for storing a desired size, wherein one edge of a sheet to be stored is stored. In a sheet cassette capable of storing sheets of an arbitrary size, a control plate is provided at one end of a housing that stores the sheets and is rotatably mounted on a bottom plate of the housing. A restricting plate that is rotatable on the opposite side to the rotation axis of the sheet placing member and regulates an edge of a sheet of the maximum size; and an end of the sheet smaller than the sheet of the maximum size is provided on the bottom plate. A movable regulating plate is provided rotatably to regulate the edge.

According to this configuration, when a sheet of the maximum size is stored, the sheet placing member is rotated so as to extend to the rear portion of the housing. Then, the regulating plate that regulates one edge of the largest-sized sheet is rotated to stand upright from the bottom plate of the housing. Thus, since one end edge of the sheet having the maximum size can be regulated, the entire sheet feeding cassette does not become large. That is, only the space of the housing that can regulate the edge of the sheet of the maximum size is sufficient. In addition, for a sheet having a size smaller than the maximum size sheet, the sheet placing member is rotated and accommodated in the housing. Then, the movable regulating plate is rotated to regulate the edge of the small-sized sheet. For this reason, the housing shape of the storage unit is adjusted according to the small sheet size, and the sheet cassette can be further reduced.

According to a fourth aspect of the present invention, the rotation axis of the movable regulating plate is coaxial with the axis for rotating the sheet mounting member. , The configuration is further simplified. That is, it is not necessary to provide a plurality of rotating shafts individually.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view for explaining a configuration according to a first embodiment of a sheet feeding cassette which is detachably or detachably provided in an image forming apparatus according to the present invention. FIG. 2 is a diagram for explaining another embodiment using the sheet cassette shown in FIG. FIG. 3 is a configuration diagram showing the overall structure of an image forming apparatus provided with the sheet cassette shown in FIG. 1 described above.

First, referring to FIG. 3, an image forming apparatus according to the present invention will be described. This image forming apparatus 1
A digital copying machine having a laser printer unit, the present invention is not limited to a sheet discharging device in a digital copying machine, but generally a sheet discharging mechanism for discharging an output sheet on which image formation has been completed. Can be applied to all. Further, the image forming apparatus is not limited to an electrophotographic printer based on a normal electrophotographic system, but may be an inkjet printer that forms an image by ink ejection,
There are thermal printers and the like that form images by thermal transfer and the like, and there are also facsimile machines and the like equipped with these printers. In these apparatuses, a sheet discharge mechanism for feeding a sheet to a target image forming position and discharging the sheet to the outside of the image forming apparatus after image formation is the same as the sheet discharge mechanism of the present invention described below. Applicable.

The main body of the image forming apparatus 1 shown in FIG. 3 has a photosensitive member 2 formed in a drum shape as a recording medium having a photoconductive layer formed on a surface rotating in the direction of an arrow as shown in the figure.
A charging unit 3 for uniformly charging the surface along the rotation direction, an exposure unit 4 for exposing the charged surface to an image, a developing unit 5 for developing an electrostatic latent image formed by exposure, and a developing unit 5 after the development. A transfer device 6 for transferring a toner image to a sheet and a cleaning device 7 for removing residual toner after transfer are arranged to face each other.

The exposure unit 4 for exposing the surface of the photoconductor 2 to an image exposes the surface of the photoconductor 2 with a laser beam 9 by a laser irradiation device 8. The laser irradiation device 8 drives the semiconductor laser ON / OFF in accordance with input image data, and the laser beam 9 is applied to another mirror and lens by the polygon mirror 10 as a polarizer in the rotation axis direction of the photoconductor 2. And so on. As a result, the laser beam 9 is applied to the surface of the photoconductor 2 uniformly charged by the charger 3.
Is irradiated, and an electrostatic latent image corresponding to the image is formed.

The electrostatic latent image formed on the photoreceptor 2 is visualized with toner in a developing device 5, and the visualized toner image is fed via a sheet conveying system. The image is transferred onto the coming sheet by the action of the transfer device (or transfer roller) 6.

In order to irradiate the photoreceptor 2 with a light image by a laser beam 9 corresponding to image data, a scanner 11 for optically reading an image of a document is provided at the upper part of the image forming apparatus 1. ing. The scanner 11 has a well-known structure, and includes a transparent platen 12 for placing the original with the image side down, a document cover 13 for pressing the original placed on the transparent platen 12 from above, a transparent cover An exposure lamp 14 for irradiating the image surface of the document from below the platen 12, a first reflecting mirror 15 for reflecting the reflected light from the document to a desired position, and forming an image of the reflected light from the first reflecting mirror 15 A pair of second and third reflection mirrors 16 and 17 that reflect toward the lens side, an imaging lens 18 that forms an image on a light receiving surface of a CCD that is a reading element that converts a light image by reflected light into an electric signal, and reading And a CCD 19 as an element.

The first reflecting mirror 15 and the exposure lamp 1
Reference numeral 4 is provided in the same scanning means, and is driven to travel in the direction of the arrow with respect to the transparent platen 12. In contrast to this scanning means, the second scanning means supporting the second and third reflection mirrors 16 and 17 is driven to run at half the running speed of the scanning means. As a result, the image of the original is sequentially formed on the light receiving surface of the CCD 19. Accordingly, electric signals corresponding to the image of the original are sequentially output from the CCD 19 as image data.

The image data is sent to an image processing circuit provided on a part of the control circuit board 20 for controlling the entire image forming apparatus 1, and the photosensitive member 2 is irradiated with the laser beam 9 described above. The data is processed as data for irradiating the surface with light and obtaining a corresponding image. The data after this processing is finally sent to the laser irradiation device 8 as image data.

According to the above description, the image forming apparatus 1 functions as a digital copier, but it can also function as a printer. That is, the image forming apparatus 1
Receives image data from another image input device (a facsimile device, a personal computer, another scanner, or the like) via a communication line, and processes the image data in the control circuit board 20 of the image forming apparatus 1 as described above. A desired image can be arbitrarily obtained by being processed as image data that can form an image by a circuit or the like and sent to the laser irradiation device 8.

Further, since the image forming apparatus 1 includes the scanner 11 as described above, the image of the original is separated into pixels and read by the CCD 19, and is passed through the image processing circuit of the control circuit board 20 to the communication line ( (Including a telephone line, etc.) to another image forming apparatus, and the image can be sent to the other party.

Next, in the above-described image forming apparatus 1, an image formed on the surface of the photosensitive member 2, that is, a toner image, is transferred onto a sheet P, and finally a sheet for outputting to the outside of the image forming apparatus 1. The transport system will be described. The sheet transport system feeds the sheet to a transfer position which is a target position facing the transfer device 6 as described above, and after the transfer, the sheet is separated from the photoreceptor 2 and connected to the main body of the image forming apparatus 1 via the heat fixing device. This is for conveying and discharging sheets one by one to a discharge tray provided in the intermediate portion.

Therefore, a sheet conveying device for feeding a sheet to the transfer position will be described. The sheet conveying device is provided with a registration roller 21 for feeding in synchronization with the rotation of the photoconductor 2. This is arranged before the transfer position (upstream side). To feed the sheet to the registration rollers 21, a sheet feeding device 22 constituting a part of the sheet conveying device is further provided on the upstream side. Have been.

The sheet feeding device 22 is provided at a lower portion of the main body of the image forming apparatus 1, that is, on the upstream side of the registration roller 21, and is used to feed another sheet as needed. A feeding device is further provided so as to be mountable below the main body of the image forming apparatus 1 as needed. Further, in the main body of the image forming apparatus 1 shown in FIG. 3, a manual sheet feeder or the like may be provided so as to protrude rightward, though not shown.

The sheet feeding device 22 has, for example, a sheet feeding cassette or tray 23 according to the present invention which can be pulled out or attached to the front side of the image forming apparatus 1 in FIG. It is configured to be able to accommodate a sheet of a size. For this purpose, a loading plate 24 is provided on which the sheets accommodated in the cassette 23 are placed. The mounting plate 24 is rotatably supported on the side opposite to the position facing the paper feed roller 25, and is rotated by an urging means such as a spring (not shown) so as to be constantly urged upward. Have been moved. Separating claws 26 are provided corresponding to both corners of the leading end of the mounting plate 24 on the sheet feeding side. The separating claws 26 regulate the floating of the sheet P on the mounting plate 24, Is always kept at a constant height.

In the non-paper feed state, the paper feed roller 2
5 is such that the string portion faces the sheet P on the mounting plate 24 as shown in FIG.
Can be put in and taken out (detachable) in this state. When the paper feed state is reached, the arc portion of the paper feed roller 25 comes into contact with the uppermost sheet on the mounting plate 24, the mounting plate 24 is pressed down, and the uppermost sheet P is Paper is gradually fed in the arc portion, and one sheet is fed with both corners of the uppermost sheet over the separation claw 26 described above.

The sheet P fed by the feed roller 25 is guided by the guide path 27 and sent to the registration roller 21 disposed on the downstream side.
The guide path 27 is provided with a sheet detection sensor 28 that detects the sheet P sent to the registration roller 21. The sheet detection sensor 28 outputs a signal for detecting the leading edge of the sheet P, and the output is used for controlling the rotation of the registration roller 21.

That is, when the sheet detection sensor 28 disposed in front of the registration roller 21 detects the leading end of the fed sheet P, the signal is received and the driving of the registration roller 21 is temporarily stopped. In particular, the registration roller 21 is controlled to be stopped with the leading end of the sheet P held therebetween. Then, the front end of the toner image formed on the photoconductor 2,
At the timing when the leading edge of the sheet P waiting on the registration roller 21 coincides with the sheet P, control is performed so that feeding of the sheet to the transfer position is restarted.

As described above, the feeding of the sheet and the feeding of the sheet to the transfer position facing the photosensitive member 2 are controlled.
The toner image formed on the photoconductor 2 is transferred onto the sheet P by the operation of the transfer device 6. After this transfer,
The sheet P is separated from the photoreceptor 2, and a heat fixing roller 29 constituting a fixing device disposed at an upper portion in FIG.
Transported to The configuration of the heat-fixing roller 29 is well known in the related art. The heat-fixing roller 29 has a roller facing the toner image surface of the sheet as a heat roller maintained at a fixing temperature, and a heat roller for pressing the sheet against the heat roller. And a pressure roller.

The toner image carried on the sheet passing through the heat fixing roller 29 is melted and fixed. Then, assuming that the image formation has been completed, the image forming apparatus 1 is finally guided along the discharge path 31 onto the discharge tray 30 arranged outside the image forming apparatus 1 and is discharged through the discharge roller 32 positioned at the discharge port. Sheet detection sensors 33 and 34 for detecting the feeding state of the conveyed sheet are provided corresponding to the paths related to the sheet discharge processing, that is, the positions of the heat fixing roller 29 and the discharge roller 32.

On the other hand, in the above-described sheet conveying device,
In order to easily remove the sheet jam in the sheet conveying path constituting the conveying apparatus, the sheet conveying path, particularly, the sheet conveying path 35 from the registration roller 21 to the transfer position corresponding to the transfer unit 6 is opened. It is configured to: That is, the image forming apparatus 1 is configured to be opened in association with the opening of the exterior (side cover or door) 36 that constitutes one side of the main body of the image forming apparatus 1 corresponding to the sheet conveying path 35.

That is, the exterior 36 is supported at the lower part of the main body of the image forming apparatus 1 so as to be rotatable around the shaft 37. At the end of the exterior 36 opposite to the support portion 37, a lock mechanism 38 for locking or unlocking the image forming apparatus 1 with the main body is provided.

When the operator releases the locked state of the lock mechanism 38, the exterior 36 can be rotated clockwise in the figure. Therefore, the sheet conveyance path 36 is opened, and the sheet P jammed at that position can be easily removed. When the process is completed, the exterior part 36 is closed, and the lock part of the lock mechanism 38 is engaged, and
Is maintained.

(First Embodiment of the Present Invention) As described above, in the image forming apparatus 1, the first embodiment according to the present invention which constitutes the sheet feeding device 22 for feeding the sheet P to the image forming position. The paper cassette 23 according to the embodiment will be described below with reference to FIG.

In particular, the paper feed cassette 23 is provided with the mounting plate 24 and the separation claw 26 as described above, and at least the paper feed roller 2 in FIG.
5 is provided with a housing 40 having one side open.

That is, the mounting plate 24 is rotatably supported in the housing 40, and the separation claw 26 prevents the sheet P mounted on the mounting plate 24 in the sheet feeding direction from floating above a certain level. Is provided so as to be restricted in rotation.

The housing 40 includes a rear end regulating plate 41 for regulating the rear end of the sheet P to be accommodated and placed on the placing plate 24. That is, when a sheet P of the maximum size accommodated in the housing 40 is accommodated, one side wall of the rear end of the housing 40 is used as a rear end regulating plate 41 in order to regulate one edge of the sheet P, for example, the rear end. We are using.

Although not shown in FIG. 1, the sheet P
A width regulating plate is provided to regulate both sides of the sheet. One of the width regulating plates is used so as to serve also as another side wall orthogonal to the rear end regulating plate 41 of the housing 40. Then, one separation claw 2 is attached to the width regulating plate.
6 is rotatably supported. The rotation state of the separation claw 26 is regulated on the upper and lower sides, and the mounting plate 24
It is possible to regulate the floating of the sheet P stored and placed on the upper part.

When a sheet having a size smaller than the maximum size of the sheets to be accommodated in the housing 40 is accommodated, the movable rear end regulating plate 4 for regulating the rear end of the accommodated sheet.
2 is provided rotatably. This movable rear end regulating plate 4
Reference numeral 2 denotes a rotatable shaft 44 rotatably supported by the bottom plate 40 a of the housing 40 of the sheet cassette 23.

The movable rear end regulating plate 42 is provided with a detection plate 42a for detecting the size integrally below the rotation shaft 44. The detection plate 42a is normally provided on the bottom plate 40 of the housing 40.
It is provided so as to protrude from the lower surface of a. That is,
In a state where the movable rear end regulating plate 42 regulates the rear end of the sheet housed in the housing 40, the detection plate 42a
0a protrudes from the bottom surface side.

When the movable rear end regulating plate 42 does not regulate the rear end of the storage sheet, the movable rear end restriction plate 42 is rotated to the position shown by the solid line in FIG. 1 and is stored in the recess 40b provided in the bottom plate 40a. It has become. In the state where the movable rear end regulating plate 42 is accommodated in the concave portion 40b, the sheet of the maximum size can be accommodated on the sheet feeding cassette 23 side, and the rear end of the maximum size sheet can be regulated by the rear end regulating plate 41. Like that.

Accordingly, the sheet cassette 23 is taken out of the image forming apparatus 1 in order to store sheets of different sizes in the sheet cassette 23 mounted at the position of the sheet feeding apparatus 22 in the image forming apparatus 1. The previously stored sheet P is removed, and a sheet of a new size is stored. In this case, if the small size is stored first, the movable rear end regulating plate 42 is rotated to be stored in the concave portion 40b of the bottom plate 40a of the housing 40 (the state indicated by the solid line in FIG. 1). Then, the rear end of the sheet having the maximum size is regulated by the rear end regulating plate 41 of the housing 40. On the other hand, at the leading end portion of the sheet P, the separation claw 26 is housed so as to be locked by its own weight on the uppermost portion of the sheet placed on the mounting plate 24, and the leading end is aligned at the position of the separation claw 26. Can be

The sheet of the maximum size is accommodated in this way, and is mounted at the position of the sheet feeding device 22 of the image forming apparatus 1 main body. In this mounting, a detection sensor 45 is provided on the body side of the image forming apparatus 1 at a position corresponding to the movable rear end regulating plate 42 as shown in FIG.
The state of a is detected. That is, the detection sensor 45 arranges a light-emitting and light-receiving element, and detects whether or not the light path is blocked by the detection plate 42a.

Therefore, when the sheet P of the maximum size is stored in the sheet cassette 23, the movable rear end regulating plate 4
2 is turned down to the unregulated position, and is accommodated in the concave portion 40 b of the bottom plate 40 a of the housing 40. for that reason,
The detection plate 42a does not block the optical path of the detection sensor 45. Thereby, the detection sensor 45 detects that a sheet of the maximum size is stored.

On the other hand, when the sheet cassette 23 accommodates a sheet smaller than the largest sheet that can be accommodated, the sheet cassette 23 is pulled out and the movable rear end regulating plate 4 is moved.
2 is rotated so as to stand upright with respect to the plane of the bottom plate 40a of the housing 40 (the state shown by the broken line in FIG. 1). The rear end of the small-sized sheet P is the movable rear end regulating plate 4.
2 to be regulated. After the sheet P is stored, the sheet feeding cassette 23 is mounted on the main body of the image forming apparatus 1, and the detection plate 42a of the movable rear end regulating plate 42 blocks the optical path of the detection sensor 45. Therefore, the detection sensor 45 detects that a small-sized sheet is stored.

As described above, in the paper feed cassette 23, one side wall of the housing 40 for storing sheets is used as the rear end regulating plate 41. For this reason, the movable rear end regulating plate 42 when accommodating a small-sized sheet is rotatably provided to the bottom plate 40 of the housing 40 at the non-regulating position.
a. Therefore, if the space housing 40 is provided in accordance with the maximum size sheet that can be accommodated in the paper feed cassette 23, it occurs when the maximum size sheet is accommodated by the conventional rear end regulating plate 54 shown in FIG. Space can be eliminated. Therefore, the entire sheet cassette 23 can be formed to be small, and at the same time, sheets of a necessary maximum size that can be accommodated can be reliably regulated and accommodated.

Here, the configuration of the trailing end regulation for regulating the trailing end of the sheet has been described. However, one width regulating plate for regulating the width direction of the sheet P is naturally provided rotatably. When the maximum size of P is accommodated, it is rotated to the non-regulated position and accommodated in the bottom plate 40 a of the housing 40. And one edge of the largest sheet is
Another side wall in a direction orthogonal to the rear end regulating plate 41 constituting the housing 40 is used as a width regulating plate. Separating claws 26 are similarly provided on the width regulating plate side.

The other separation claw 26 is provided on the rotatable width regulating plate side so as to be rotatable on the width regulating plate side. When the rotatable width regulating plate is pivoted to the unregulated position, the separation claw 26 is also accommodated in the recess of the bottom plate 40a.

(Another Aspect According to First Embodiment) The movable rear end regulating plate 41 of the sheet cassette 23 described with reference to FIG.
The configuration has been described as being rotatable at that position.
Therefore, the sheet cassette 23 can only accommodate two types of sheets, large and small. Therefore, it is more convenient to use the sheet feeding cassette 23 if the sheet cassette 23 is configured to accommodate sheets of other sizes and to control the trailing edge.

That is, in the description of FIG. 1, for example, as the sizes of the sheets P that can be accommodated, the standard sizes B4 and A4
In the following, an example will be described in which, when the sheet size can be accommodated and regulated, sheets of other sizes such as B4 and A5, and sheets of irregular size smaller than B4, which is the maximum size, can be accommodated.

Therefore, the movable rear end regulating plate 42 is provided so as to be rotatable and slidable in the left-right direction in FIG. The slide mechanism may use a conventionally known mechanism as it is. For example, the housing 40
Slide plate 4 slidably provided on bottom plate 40a
6 is provided, and a rotating shaft 43 is rotatably supported on one end side of the slide plate 46. The slide plate 46 is slidably provided on a bottom plate 40 a of the housing 40.
As is well known in the related art, for example, positioning and locking are performed at a fixed size position.

Then, the movable rear end regulating plate 42 is
As shown in the figure, the space is provided so as to be accommodated in a space portion on the slide 46 side in a state of being rotated and fallen.

According to such a configuration, the paper feed cassette 2
When the size of a sheet that is one size smaller than the maximum size that can accommodate 3 sheets, for example, a sheet of B4 size, is maximized, A
In a four-size sheet, the movable rear end regulating plate 42
It is located in the state shown in FIG. 2 (the state shown by the broken line) and regulates the rear end of the sheet of that size. Then, the detection plate 42a shields the optical path of the detection sensor 45 and detects that an A4 size sheet is stored.

When a sheet smaller than the A4 size is to be stored, the movable rear end regulating plate 42 is further moved rightward through the slide plate 46 in the state shown in FIG. The rear edge of the size sheet is regulated. For size detection at such a regulated position, the same one as the detection sensor 45 is provided individually corresponding to each size. Thereby, the movable rear end regulating plate 4
The size detection can be performed by the second detection plate 42a blocking the optical path of the detection sensor.

According to the configuration described above, the movable rear end regulating plate 42 is rotatably provided on a conventionally known slide mechanism so that the rear end of sheets of any number of sizes can be regulated. become. Further, by rotating to the non-regulating position, one side wall of the housing 40 can be used as the rear end regulating plate 41 to regulate the rear end of the sheet of the maximum size. In addition, the trailing edge of a sheet of irregular size can be similarly regulated.

It is needless to say that the regulating plate in the width direction of the sheet P may have the same configuration as that described above.

(Second Embodiment of the Present Invention) Next, the configuration of the sheet cassette 23 according to a second embodiment of the present invention will be described with reference to FIG. In this embodiment, when storing small-sized sheets, the entire sheet cassette 23 can be made even smaller.

In FIG. 4, a sheet placing member 47 is provided at the rear end of the sheet feeding cassette 23 so as to be rotatable on the bottom plate 40a of the housing 40. The mounting member 47 is rotatably provided coaxially with the rotation shaft 43 of the movable rear end regulating plate 42, for example.

The sheet mounting member 47 is normally accommodated in the bottom plate 40a of the housing 40, and is rotated about the rotation shaft 43 in the direction of the dashed arrow when necessary, as shown in FIG. Projecting from the rear end portion, that is, extending to the rear end portion of the bottom plate 40a of the housing 40 (the state shown by the solid line). A shaft 48 is provided on the opposite side of the rotation shaft 43 of the sheet placing member 47.
Is provided at the rear end regulating plate 49 which is rotatable about the maximum sheet.

Then, in a state where the sheet placing member 47 is rotated and accommodated in the bottom plate 40 a of the housing 40,
The movable rear end regulating plate 42 is provided so as to be accommodated in the sheet placing member 47. In particular, the movable rear end regulating plate 42 is rotatably provided on a rotating shaft 43 rotatably supported by the bottom plate 40 a of the housing 40. And this rotating shaft 4
The sheet mounting member 47 described above is rotatably provided with 3 being coaxial.

In the above configuration, when a small-sized sheet is stored in the sheet cassette 23, the sheet mounting member 47 is held in a state of being stored in the bottom plate 40 a of the housing 40. In this state, the movable rear end regulating plate 42 accommodated in the sheet placing member 47 is turned around the turning shaft 43 so as to stand upright with respect to the surface of the bottom plate 40a. In this state, the rear end of the sheet P accommodated in the housing 40 is regulated by the movable rear end regulating plate 42.

On the other hand, when the largest size sheet that can be accommodated in the sheet cassette 23 is accommodated, the movable rear end regulating plate 42 is turned around the turning shaft 43 to be accommodated in the sheet placing member 47. I do. Then, the sheet placing member 47 is rotated by 180 ° counterclockwise in FIG. 4 (in the direction of the dashed arrow) about the rotation shaft 43, and the state shown by the solid line in FIG. 4 is obtained. In this state, the rear end regulating plate 49 having the maximum size is further rotated around the shaft portion 48 in the counterclockwise direction (the direction indicated by the dashed arrow) to stand upright. Thereby, the rear end of the sheet of the maximum size can be regulated and the sheet can be accommodated.

According to the paper feed cassette 23 having such a configuration, when the sheets of the maximum size are stored, the entire paper feed cassette 23 can be similarly made small without using any unnecessary space. When a small-sized sheet is stored, the sheet placing member 47 is attached to the bottom plate 40 of the housing 40.
a, the movable rear end regulating plate 42 is rotated so as to regulate the rear end of the small size sheet,
0a. Therefore, the size of the housing 40 is reduced to a state in which small-sized sheets can be stored, and the size of the entire sheet feeding cassette 23 is further reduced.

As described above, since the rotating shaft 43 of the movable rear end regulating plate 42 is coaxial with the rotating shaft of the sheet placing member 47, the configuration is simpler than when they are separate shafts. Become. Further, the coaxial configuration allows the sheet placing member 47 to be rotated in order to accommodate a sheet of the maximum size even when the movable rear end regulating plate 42 is provided at the regulating position. And the movable rear end regulating plate 42 can be accommodated at the same time.

In the embodiment described above, the detection sensor 45 for detecting the size of the accommodated sheet is provided.
Detection plate 42 for blocking the optical path of this detection sensor 45
a is provided integrally with the movable rear end regulating plate 42 which is rotated. In the configuration of the detection plate 42a, the bottom plate 40 of the housing 40 is
a protrudes from the lower surface. Therefore, it may be in the way. In order to solve this, a reflecting plate is provided on the regulating surface of the movable rear end regulating plate 42 or on the opposite surface thereof, that is, on the surface that is turned and faces the bottom plate 40a. And
By irradiating the reflecting plate with light from the lower surface side of the bottom plate 40a of the housing 40 and receiving the reflected light, the position of the rear end regulating plate 42 can be detected. Thereby, size detection can be performed in a similar manner.

[0076]

The sheet cassette provided in the image forming apparatus of the present invention is not affected by the presence of the movable regulating plate for regulating the edge of the small-sized sheet, and the sheet edge of the largest size that can accommodate the cassette is provided. This uses a housing having a space capable of regulating the size of the cassette, so that the housing itself can be prevented from becoming large and the cassette itself can be made small.

The movable regulating plate is rotated so as to be accommodated in the bottom surface of the casing of the cassette, so that the movable regulating plate is not lost.

If the movable regulating plate is provided so as to be slidable at the same time, sheets of other sizes can be arbitrarily accommodated.

Further, a sheet mounting member having a rotatable rear end portion of the housing is accommodated in the bottom surface of the housing, and is rotated when a sheet of the maximum size is stored, so that the sheet mounting member can be rotated by the sheet mounting member. A moving rear end regulating plate can be provided, so that when accommodating small-sized sheets, the entire cassette can be made even smaller.

If the sheet placing member is coaxial with the movable rear end regulating plate, the configuration of the sheet cassette can be simplified.

[Brief description of the drawings]

FIG. 1 is a side view of a first embodiment of a sheet feeding cassette provided in an image forming apparatus according to the present invention, particularly showing a portion for regulating a rear end of a sheet.

FIG. 2 is a plan view for explaining another mode of the sheet cassette shown in FIG.

FIG. 3 is a configuration diagram for describing an internal structure of an image forming apparatus including the sheet cassette illustrated in FIG. 1;

FIG. 4 is a side view of a sheet cassette provided in an image forming apparatus according to a second embodiment of the present invention, particularly showing a portion that regulates a rear end of a sheet.

FIG. 5 is a plan view for explaining a configuration of a conventional sheet cassette.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Photoreceptor 5 Developing device 6 Transfer device 22 Sheet feeding device 23 Paper feed cassette 40 Housing 40a Bottom plate 40b Depression 41 Rear end regulating plate 42 Movable rear end regulating plate (movable regulating plate) 43 Rotation axis 44 times Active shaft 45 Detection sensor 46 Slide plate (slide member) 47 Sheet mounting member 48 Shaft 49 Rear end regulating plate

Continued on the front page (72) Inventor Yoshiyuki Shiraishi 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor Fumio Shiozaki 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Sharp Corporation (72) Inventor Toshihiko Seike 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Minoru Tomi 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka F-term (Reference) 2H072 BA12 BB02 BB04 3F343 FA02 FB01 GA01 GB01 GC01 GD01 HB03 HE02 HE08 HE13 HE15 JA01 LA04 LA15 LA16 LC04 LC19

Claims (4)

[Claims] 1. A sheet feeding cassette for storing a desired size, comprising a regulating plate for regulating one edge of a sheet to be accommodated, and capable of accommodating a sheet of an arbitrary size. A movable regulating plate that rotatably regulates one end edge of the sheet is provided on a bottom plate of a housing that accommodates the sheet, and the regulating plate is pivoted to a non-regulating position to accommodate the sheet in the bottom plate. In such a state, one side wall of the housing corresponding to the movable regulating plate can be used as a regulating plate for regulating one edge of a sheet. 2. The sheet cassette according to claim 1, wherein the movable regulating plate is provided rotatably with respect to a slide member provided slidably with respect to a bottom plate of the housing. 3. A sheet feeding cassette for storing a desired size, comprising a regulating plate for regulating one edge of a sheet to be accommodated, and capable of accommodating a sheet of an arbitrary size. A sheet mounting member is provided at one end of a housing that houses the sheet and is rotatably accommodated in a bottom plate of the housing, and is rotatable on a side opposite to a rotation axis of the sheet mounting member and has a maximum. A feeder, wherein a regulating plate for regulating an edge of a sheet of a size is provided, and a movable regulating plate is rotatably provided on the bottom plate for regulating an edge of a sheet smaller than the sheet of the maximum size. cassette. 4. The sheet feeding cassette according to claim 3, wherein a rotation axis of the movable regulating plate is at the same time as an axis that rotates the sheet placing member.