JPH0433691B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a paper feeding device that uses a large-capacity cassette as a paper cassette for storing paper to be fed into an image forming apparatus main body.

<Prior Art and Its Disadvantages> Generally, sheets to be fed to the main body of an image forming apparatus are stored in paper cassettes for each size, and the paper cassettes are attached to the main body of the image forming apparatus to feed the paper. However, although this paper cassette can normally hold about several hundred sheets of paper, if you use a large amount of paper, the paper in the paper cassette will run out quickly and you will have to replenish the paper cassette frequently. There are drawbacks that can be avoided.

Conventionally, it has been possible to reduce the number of times the paper cassette needs to be refilled by installing a large capacity cassette that can store several thousand sheets of paper into the main body of the image forming apparatus.

Conventionally, this large-capacity cassette is used for devices that have built-in large-capacity cassettes that can store paper of A4 size or smaller in advance inside the image forming apparatus main body, and for devices that have built-in large capacity cassettes that can store paper of A4 size or smaller. An optional cassette loading device that allows you to attach a large-capacity paper cassette to the position where a paper cassette containing several hundred sheets is installed is used, but it is possible to store paper cassettes of A4 size or smaller. The device has a large-capacity cassette built into the main body of the image forming device, so there are no space constraints, but it has the disadvantage that it cannot store paper larger than A4 size, and devices equipped with a larger-capacity cassette of B4 size or smaller cannot accommodate large-capacity cassettes. Since it always protrudes to the side of the image forming apparatus main body, the size of the image forming apparatus main body itself increases, resulting in poor operability and increased costs. In addition, if a large-capacity cassette is installed as an option, the paper cassette becomes unusable because it is installed in the part of the normal cassette for several hundred sheets. There were inconveniences such as the inconvenience of protruding into the area and poor operability, and the inconvenience of an unsightly design.

<Object of the invention> The object of the invention is to be able to store both small-sized paper and large-sized paper in a large-capacity cassette, and to improve operability when small-sized paper is stored in a large-capacity cassette. To provide a paper feeding device equipped with a large-capacity cassette without any problem.

<Configuration and Effects of the Invention> The present invention stores a large number of small-sized sheets in a large-capacity cassette for small sizes built into the main body of an image forming apparatus, and moves the bottom plate of the large-capacity cassette up and down. In a paper feeding device that feeds paper from above using a cassette, an additional cassette having a vertically movable bottom plate is removably attached to the large-capacity cassette for small sizes, and the additional cassette is attached above and below the bottom plate of the large-capacity cassette for small sizes. The present invention is characterized in that means is provided for transmitting the driving force of the moving device to the bottom plate of the additional cassette.

According to the present invention configured as described above, when it is desired to use small-sized paper, it can be stored in a large-capacity cassette for small-sized paper built into the main body of the image forming apparatus. Since the large-capacity cassette for small sizes is built into the main body of the image forming apparatus, there is no space restriction and no deterioration in operability occurs. Paper can be fed from the top by moving the bottom plate of this large capacity cassette up and down. Further, when it is desired to use large-sized paper, the large-sized paper can be stored by attaching an additional cassette to the large-capacity cassette for small size. The driving force for vertically moving the bottom plate of the large-capacity cassette for small sizes is transmitted to the additional cassette, and by using this driving force to move the bottom plate of the additional cassette up and down, large-sized paper can be removed from the top of the large-capacity cassette. can be fed.
In this way, the present invention uses a large-capacity cassette built into the main body of the image forming apparatus when using small-sized paper, so it is efficient in terms of space and operability.
It is possible to feed large-sized paper from the large-capacity cassette by simply attaching an additional cassette to the small-sized large-capacity cassette, which has the advantage of lower costs. In addition, since the driving force for vertically moving the bottom plate of the large-capacity cassette for small size can be transmitted to the additional cassette, there is no need to provide a drive device for the additional cassette, which reduces the cost and makes it easier to install the additional cassette. It has the advantage of being easier.

<Embodiment> FIG. 2 is a schematic diagram of an image forming apparatus equipped with a paper feeding device according to an embodiment of the present invention. In the figure, a photoreceptor drum 12 is provided in the center of an image forming apparatus main body 11, and a photoreceptor drum 12 is provided on the side.
A paper feeding device 1 for feeding paper is provided at 2 . The paper feeding device is composed of small capacity cassettes 13a, 13b, 13c that store several hundred sheets of paper, and a large capacity cassette 2 for small sizes that stores several thousand sheets of paper built into the image forming apparatus main body 11. be done. Paper is fed to the small capacity cassettes 13a, 13b, and 13c by paper feed rollers 14a, 14b, and 14c, respectively. Paper is fed to the small size large capacity cassette 2 by a paper feed roller 2a,
The photoreceptor drum 12 is transported by transport rollers 2b, 2c, and 2d.

FIG. 3 is a perspective view of this image forming apparatus. The large capacity cassette 2 for small size is composed of a large capacity cassette main body 21 and a side plate 22. The side plate 22 can be replaced by attaching and detaching the additional cassette body 21' and bolts 23.

FIGS. 1A and 1B are diagrams showing the configuration of a large capacity cassette to which an additional cassette is attached. FIG. 1A is a configuration diagram seen from the front, and FIG. 1B is a configuration diagram seen from above.

In the figure, large capacity cassette main body 21 for small size
A frame 31 is provided inside. The frame 31 has a U-shape and is open on the right side. Two parallel frames 31' are provided at the front and rear inside the additional cassette main body 21'. These frames 31, 31' abut at points a and b in the figure.

A bottom plate 32 is disposed within the frame 31 on which a small-sized paper (A4 size or smaller) is placed. A paper guide (not shown) is provided on the frame 31 and is slidable in the front-rear direction. By determining the position of this paper guide, it becomes possible to place paper of A4 size or smaller on the bottom plate 32. Notches 31a and 31b are symmetrically formed in the front and rear plates of the frame 31, respectively. Further, protrusions 32a, 32 are provided at the front and rear ends of the bottom plate 32.
b is integrally formed. This protrusion 32a, 3
2b are the cutout portions 31a and 31b, respectively.
It projects outward (anteriorly and posteriorly) from the One ends of belts 33a, 33b, which will be described later, are attached to the protrusions 32a, 32b.

The belts 33a, 33b are connected to each other via an idle pulley 34 supported outside the upper part of the frame 31.
The other end is locked to a pulley 35 provided outside the upper part of the small size large capacity cassette main body 21.

A bottom plate 32' is disposed within the frame 31'. When the additional cassette is attached, the tip of the bottom plate 32' is engaged with the upper surface of the rear end of the bottom plate 32. A paper guide (not shown) is also arranged on the bottom plate 32'. By sliding this paper guide and the paper guide provided on the bottom plate 32, sheets of all sizes up to A3 size can be placed. In this embodiment, sheets of up to A3 size can be placed, but the additional cassette may be made larger so that sheets of even larger size can be placed.

The bottom plate 32' has a protrusion 3 similar to the bottom plate 32 described above.
2'a and 32b' are provided. In addition, the front and rear plates of the frame 31' have cutout portions 31a',
31b' is provided. This notch 31
The protrusions 32a', 32b' protrude outward from a', 31b'. Belts 33a', 33b' are engaged with the ends of the protrusions 32a', 32b', and the bottom plate 32' is suspended. Belt 33a', 3
3b', like the belts 33a and 33b, is connected to pulleys 35a' and 35b' provided outside the bottom of the additional cassette body 21' via an idle pulley 34' supported outside the top of the frame 31'. It is locked.

A gear portion 4 is provided at the bottom of the large capacity cassette main body 21 for small size and the additional cassette main body 21', respectively.
4' is located. A first shaft 41 extending in the left-right direction, a second shaft 42 extending in the front-rear direction, and a pulley shaft 35c having the pulleys 35a and 35b fixed at both ends are arranged within the gear portion 4. The first shaft 41 is connected to a motor 44 via a first gear portion 43 . The motor 44 is in the forward direction;
It can be rotated in either direction. The second shaft 42 is interlocked with the first shaft 41 by a worm gear 45a and a worm wheel 45b. The second shaft 42 provides a driving force to the pulley shaft 33c through a second gear portion 46.

Inside the gear portion 4' in the additional cassette main body 21' are a first shaft 41' in the left-right direction, a second shaft 42' in the front-back direction, and a pulley shaft 35c with the pulleys 35a' and 35b' fixed at both ends. ' and are arranged. This first shaft 41' is connected to the first shaft 41 by a mechanical coupling 47.
This connection is obtained simultaneously when installing additional cassettes. In this embodiment, a mechanical coupling device is used for the connection portion, but an electrocoupling device may also be used. The second shaft 42' is connected to the first shaft 41' by a worm gear 45a' and a worm wheel 45b'. The second shaft 42' is connected to the pulley shaft 33c by a second gear portion 46'.

With the above configuration, according to this embodiment, the side plate 22 of the large capacity cassette main body 21 for small size can be easily removed by removing the bolt 23, and then the additional cassette main body 2 can be removed.
1' can be attached. The additional cassette main body 21' can be attached to the large capacity cassette main body 21 for small size by a simple operation of engaging the mechanical coupling 47, the frames 31, 31', and the bottom plates 32, 32' and tightening the bolts 23. I can do it. In the large capacity cassette main body 21 for small size with the additional cassette main body 21' attached, the bottom plate 3
Paper up to A3 size can be placed by sliding the paper guides on 2 and 32'.

Next, the operation of this device will be explained.

When the motor 44 rotates, the driving force of the bottom plates 32, 32' is transmitted to the first shaft 41 by the first gear portion 43. The driving force of the first shaft 41 is transmitted by a mechanical coupling 47 to the first shaft 41'. The driving force of the first shafts 41, 41' is applied to the worm gears 45a, 45a' and the worm wheel 4.
5b, 45b' to the second shaft 42, 42'. The driving force of the second shafts 42, 42' is transmitted to the pulley shafts 35c, 35c' by the second gear parts 46, 46', and the driving force is transmitted to the pulley shafts 35c, 35c'.
35b, 35a', and 35b' rotate synchronously. When the motor 44 rotates in the forward direction, the pulley 35
The belts 33a, 33b, 33a', 33b' are wound up by the rotation of the belts 33a, 35b, 35a', 35b', and the protrusions 32a, 32 are locked at one end.
b, 32a', 32b' move the bottom plates 32, 32' upward. In this way, the bottom plates 32, 3
2' moves upward, and the paper is fed to the photosensitive drum 12 by the rotation of the paper feed roller 21a. In addition, when placing paper on the bottom plate, the motor 44
By rotating in the opposite direction, the pulley 35
The belts 33a, 33b, 33a', 33b' wound around a, 35b, 35a', 35b' are unwound, and the bottom plate is lowered. In this state, the bottom plates 32, 32'
Paper can be placed on top.

In this embodiment, in this way, only the large-capacity cassette for small sizes that can be built into the image forming apparatus main body 11 is built into the image forming apparatus main body 11, and when it is desired to store larger-sized paper in the large-capacity cassette. Additional cassettes can be added and used with simple operations. As a result, when small-sized paper is stored in a large-capacity cassette, the additional cassette can be removed and used with good spatial maneuverability, and the additional cassette can be attached and used with a simple operation. Therefore, large-sized paper can also be stored in the large-capacity cassette. Furthermore, since the driving force of the motor is transmitted to the additional cassette through the shaft, there is no need to provide a motor to the additional cassette, and installation is simple. Furthermore, as a method of transmitting the driving force, in this embodiment, belts are provided for each of the small-sized cassette and the additional cassette, but there are other methods such as using one belt to move both bottom plates.

[Brief explanation of drawings]

FIG. 1A is a schematic diagram of the large-capacity cassette portion of a paper feeder according to an embodiment of the present invention, viewed from the front, and FIG. 1B is a schematic diagram of the configuration viewed from above.
FIG. 2 is a schematic configuration diagram of an image forming apparatus to which this paper feeding device is applied, and FIG. 3 is a perspective view thereof. 2... Large capacity cassette for small size, 2'... Additional cassette, 21... Large capacity cassette main body for small size, 21'... Additional cassette main body, 23... Bolt, 32, 32'... Bottom plate.

Claims (1)

[Scope of Claims] 1. A large number of small-sized sheets are stored in a large-capacity cassette for small sizes built into the main body of an image forming apparatus, and the bottom plate of the large-capacity cassette is moved up and down. In a paper feeding device that feeds paper from a small size large capacity cassette, an additional cassette having a vertically movable bottom plate is removably attached to the small size large capacity cassette, and a device for vertically moving the bottom plate of the small size large capacity cassette is driven. A paper feeding device comprising means for transmitting force to the bottom plate of the additional cassette.