JPH0717650A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce apprehension of a double feed by opening a device side wall with a supporting shaft provided in a paper feed end side serving as the center, providing a loading base part capable of mounting transfer paper on the side wall, and also making a turn supporting point of a friction pad agree with the supporting shaft of the side wall, so that a stable contact pressure of a loading base with a paper feed roller is maintained. CONSTITUTION:A friction pad member 12 and a turn supporting point 3a of a side wall 3, mounting a loading base 2 through a cover member 21, are commonly formed. The loading base 2 is extended along an upper surface of the side wall 3 through the cover member 21, and a turn arm member 121 of the friction pad member 12 is extended in a side of a paper feed roller 5, to provide a both-turn mechanism in narrow space under the paper feed roller S. Further, since the supporting shaft 3a of the arm member 121 of the friction pad member 12 is provided in a position most adjacent to the device side wall 3 in a paper feed end side, a turn distance between contact positions of the pad supporting shaft 3a and a friction pad 12a can be longest taken. Accordingly, a double-feed can be reduced.

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 applied as a facsimile, a printer or a copying machine, and more particularly to an image forming apparatus having a sheet feeding section provided on the side wall of the apparatus which can be opened.

[0002]

2. Description of the Related Art Conventionally, sheet materials of a predetermined size are stacked and stored as a feeding mechanism for automatically feeding the originals or transfer sheets of copying machines or facsimiles, recording sheets of printers (hereinafter referred to as sheet materials) one by one. The assembled cassette is attached to the apparatus main body side, and the feeding means such as a paper feed roller on the apparatus main body side
There are a cassette sheet feeding method for feeding sheets one by one and a stacking sheet feeding method for feeding sheet materials directly loaded on a loading table in the apparatus main body one by one by a feeding means. The latter method is It is simple and versatile because it is sufficient to place several tens of sheet materials of arbitrary size directly on the stacking table, and is therefore often used in low-cost image forming apparatuses for personal use.

On the other hand, in any of the above-mentioned paper feeding methods, it is difficult to reduce the size of the apparatus as a whole because the paper feeding portion is provided so as to project larger than the side wall of the apparatus main body. In the above configuration, the paper feed cassette is arranged on the bottom side of the apparatus main body. However, it is difficult to take the above configuration because it is integrated with the apparatus main body in the loading platform method. Therefore, by mounting the paper feed tray on the side wall of the main body of the apparatus like a manual paper feed mechanism for manually feeding paper one by one, and making the side wall openable and closable, it is possible to feed the paper together with the side wall during non-printing. Attempts have been made to store the paper tray in the main body of the apparatus.

[0004]

However, in the above-described loading table system, a friction pad is provided on the downstream side of the portion of the loading table that is in contact with the sheet feeding roller, and the friction pad, the sheet feeding roller and the transfer roller are provided. Since it is possible to feed the sheets one by one due to the three factors of the frictional force of the leading edge of the sheet, it is difficult to accurately maintain the contact pressure with the sheet feeding roller in the mechanism for opening and closing the stacking table as described above. Further, since a spring and other members are interposed between the loading table and the side wall, it is difficult to store the spring and other members in the apparatus main body in a thin space.

Further, in order to maintain the contact pressure of the friction pad at a predetermined level so that the friction pad can be pressed against the paper feed roller side, the press contact mechanism and the rotation fulcrum must be provided on the apparatus main body side, but the paper feed unit end side Not only is it difficult to provide both the opening / closing shaft of the side wall and the rotation mechanism of the friction pad in a narrow space of the paper feed roller, but also the contact position of the friction pad and the distance between the rotation fulcrums are particularly difficult. If it is short, the contact pressure will fluctuate due to slight eccentricity of the paper feed roller, assembly error, etc.
There is a risk of double feeding.

In view of the drawbacks of the prior art, the present invention has been made.
Even when the stacking base is attached to the side wall of the device and can be stored in the main body of the device during non-printing, it is possible to store in a small space while stabilizing the stacking base and the paper feed roller on the side wall of the device. An object of the present invention is to provide an image forming apparatus capable of maintaining a constant contact pressure. It is another object of the present invention that both the opening / closing shaft of the side wall and the rotation mechanism of the friction pad can be effectively arranged in the narrow space below the paper feed roller even when the side wall can be opened and closed. An object of the present invention is to provide an image forming apparatus capable of maximizing the distance between the contact position of the friction pad and the rotation fulcrum, thereby greatly reducing the risk of double feeding even when the stacking table is provided on the openable and closable side wall.

[0007]

According to a first aspect of the present invention, there is provided an image forming apparatus in which a friction pad is brought into pressure contact with a peripheral surface of a sheet feeding roller which is in contact with a transfer sheet and the sheet is fed one by one. The side wall of the device is configured to be openable around a support shaft provided on the end side, and a stacking base on which a large number of transfer papers can be stacked is provided on the side wall, and a rotation fulcrum of the friction pad is provided on the side wall. It is characterized by matching with the support shaft.

According to a second aspect of the present invention, in an image forming apparatus in which the side wall of the apparatus can be opened around a support shaft provided on the side of the sheet feeding end, the sheet feeding unit is elastically moved toward the sheet feeding roller. An elastic member for urging the sheet feeding unit and a fulcrum for swinging the sheet feeding unit in the direction toward and away from the sheet feeding roller are sequentially arranged on the side wall along the side wall open end side of the supporting shaft, A large number of transfer papers can be stacked on the unit, and a pressing member that presses the paper feeding unit is provided on the apparatus main body side facing the side wall, and the paper feeding unit presses the pressing member when the side wall is closed. It is characterized in that it is configured so that it can be stored while being folded against the side wall against the elastic force.

[0009]

According to the first aspect of the invention, the friction pad and the side wall of the side wall on which the loading platform is provided are formed in common, and the loading platform is provided on the side wall side and the pad pivoting mechanism is provided. Since the structure extends in the direction opposite to the paper roller side, it is easy to provide both rotation mechanisms in a narrow space below the paper feed roller, and the friction pad support shaft is provided on the paper feed end side. It can be provided at a position closest to the side wall of the device, and therefore the rotation distance between the contact position of the pad support shaft and the friction pad can be set to be the longest. The fact that the rotation distance can be made long allows the fluctuation of the contact pressure to be suppressed even if a slight eccentricity of the sheet feeding roller or an assembly error occurs, and the fear of double feeding can be eliminated.

Next, the operation of the invention described in claim 2 will be described. As described above, there is no technique in which a stacking unit for stacking a large number of transfer papers is provided on the side wall of the apparatus, and the technique can be achieved for the first time in the present invention. Further, according to the present invention, since the supporting shaft of the stacking table is arranged on the side wall free end side farthest from the sheet feeding roller, the contact position with the sheet feeding roller located on the side wall proximal end side of the stacking table is set. The rotation distance to the rotation fulcrum can be made the longest, and therefore, slight eccentricity of the paper feed roller, assembly error, etc. occur, and the contact pressure with the paper feed roller can be accurately maintained. Further, according to the present invention, since the pressing member for pressing the loading table is provided on the apparatus main body side facing the sidewall, the loading table is pressed by the pressing member when the sidewall is closed and resists the elastic force to the sidewall side. It can be folded and stored. As a result, even if a spring or other member is interposed between the stacking base and the side wall, the member is automatically stored in the apparatus main body in a state of being pressed and thinned.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention thereto, unless otherwise specified. It is merely an example of explanation. 1 to 3 show an LE according to an embodiment of the present invention.
FIG. 1 is a cross-sectional view showing a configuration of a paper feed unit side of the D printer, FIG. 1 showing a state in which the side wall is opened, and FIG. 2 showing a state in which the side wall is closed.
FIG. 3 is an exploded perspective view showing the area around the loading platform mounted on the side wall.

In this embodiment, the side wall 3 forming a part of the casing 1 of the apparatus is constructed so that it can be raised and lowered about a fulcrum 3a provided at the lower end, and when it is laid down substantially horizontally with a slight upward inclination angle. The stacking table 2 is arranged on the upper surface of the side wall 3 so that the position of the stacking table 2 can be regulated, and the tip of the stacking table 2 is fed by the spring force of the coil spring 4 when the side wall 3 is laid down.
When the side wall 3 is erected, the stacking base 2 is pressed against a part of the rear wall 11a of the unit frame 11 that supports the transfer roller 16 and the paper feed tray 2 is stored tightly against the spring force of the coil spring 4. Configure as possible. Then, a transfer sheet conveying path 10 is formed in a substantially vertical direction from the sheet feeding roller 5 toward the upper surface sheet discharging portion 9 side.

Then, the friction pad member 12 and the paper detection sensor 1 are arranged in this order along the recording paper carrying direction of the carrying path 10.
4, transfer roller 16, photosensitive drum 17, fixing roller 1
8, the discharge roller 19 is provided, and the photosensitive drum 1
Developing unit 2 having a developing sleeve 20a on the lower side of
0 and the LED unit 13 is arranged on the side thereof. The loading platform 2 is attached to the upper surface of the apparatus side wall 3 via a cover member 21, and biases an elastic force toward the sheet feeding roller 5 via a coil spring 4 and a pressure contact plate 22.

The structure will be described with reference to FIG. The cover member 21 surrounds the edge wall 2a on three sides of the rectangular bottom plate excluding the paper feed roller 5 side, and the support shafts 3a are sequentially provided from the paper feed roller 5 side to the portions facing the left and right edges of the edge wall 2a / 2a. Shaft hole 211 for pivotally supporting the side wall 3 via the press contact plate 2
2, a shaft hole 212 for swingably supporting the shaft 2 through a shaft 22a,
Also, a long hole 213 that pivotally supports the loading table 2 via a shaft 2a is bored, and two holes 215 through which the coil spring 4 is inserted are bored in the bottom plate 214. The press contact plate 22 includes a shaft 22a that is axially supported by the cover member 21.
The coil spring 4 is bent toward the side of the coil spring 4 in a U-shape, and the coil spring 4 is configured to be capable of receiving pressure on the lower surface side thereof, and a plurality of corrugated plates 222 are attached to the upper surface side thereof to mount the loading table 2 on the shaft 2a. The elastic force can be applied to the side of the paper feed roller 5 around the center. The loading table 2 is provided with a pad 2b at a tip end portion which is in contact with the sheet feeding roller 5, and a strip-shaped slit hole 2d extending in the width direction at a central portion, and a position regulating plate 2c is slid in parallel along the strip-shaped slit hole 2d. Install movably. Further, the loading table 2 pivotally supports a guide guide 24 that can be folded by 180 ° on the rear end side. The friction pad member 12 has an arm member 121 extending stepwise on the shaft of the side wall 3 that supports the cover member 21, and further downstream of the leading end of the stacking table 2 that is in contact with the peripheral surface of the paper feeding roller 5. The front side of the arm member 121 contacts the five circumferential surfaces, and the friction pad 12a is attached to the upper surface of the front side. A coil spring 24 is interposed on the back side of the friction pad 12a attachment portion, and the pad 12a is pressed against the paper feed roller 5 side.

According to this embodiment, the friction pad member 12 and the pivot 3a of the side wall 3 to which the loading platform 2 is attached via the cover member 21 are formed in common, and the loading platform 2 is formed. Is the side wall 3 through the cover member 21.
The friction pad member 12 extends along the upper surface.
Since the rotating arm member 121 of FIG. 2 is extended toward the sheet feeding roller 5 and extends in the directions opposite to each other, it is easy to provide both rotating mechanisms in a narrow space below the sheet feeding roller 5. Yes, the arm member 1 of the friction pad member 12
The support shaft 3a of 21 can be provided at the position closest to the side wall 3 of the apparatus on the sheet feeding end side, and therefore, the rotation distance between the contact position between the pad support shaft 3a and the friction pad 12a can be set to be the longest. . Further, according to the present embodiment, the side wall 3 is laid down substantially horizontally about the fulcrum 3a provided at the lower end, so that the coil spring 4 provided on the side wall 3 covers the back surface of the loading table 2 via the cover member 21. The supporting shaft of the loading table 2 is urged and the side wall 3 that is farthest from the paper feed roller 5.
Since it is arranged on the free end side through the cover member 21, the rotation distance from the contact position with the sheet feeding roller 5 located on the base end side of the side wall 3 of the stacking table 2 to the rotation fulcrum 3a is set. The side wall 3 can be made as long as the length of the side wall 3. Therefore, a slight eccentricity of the sheet feeding roller 5, an assembly error or the like occurs, and the contact pressure with the sheet feeding roller 5 can be accurately maintained.

Further, in the present embodiment, after the guide guide 24 is folded 180 ° to the upper surface side of the loading table 2 at the time of non-printing, the side wall 3 is erected so that the transfer roller 16 provided on the apparatus main body side. Rear wall 11 of unit frame 11
While a presses the loading table 2 and resists the elastic force of the coil spring 4, it can be folded together with the cover member 21 on the side wall 3 side and can be stored tightly.

[0017]

As described above, according to the first aspect of the invention, even when the side wall can be opened and closed, the shaft for opening and closing the side wall and the friction pad are effectively provided in the narrow space below the sheet feeding roller. It is possible to dispose both of the rotation mechanisms of the above, and the distance between the contact position of the friction pad and the rotation fulcrum can be made as long as possible, thereby increasing the risk of double feeding even when a loading platform is provided on the side wall that can be opened and closed. It can be reduced. According to the second aspect of the invention, even when the loading platform is attached to the side wall 3 of the apparatus so that it can be stored in the apparatus main body side during non-printing, it can be stored in a space-saving manner. It is possible to maintain a stable contact pressure between the stacking table on the side wall of the apparatus and the sheet feeding roller. It has various remarkable effects.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a sheet feeding side of an image forming apparatus according to another embodiment of the present invention, showing a state in which a front wall is opened.

FIG. 2 shows a state in which the front wall of FIG. 1 is closed.

3 is a schematic exploded perspective view of the paper feed mechanism of FIG.

[Explanation of symbols]

5 Paper Feed Roller 12 Friction Pad Member 3a Spindle (Rotation Support Point of Friction Pad and Loading Platform) 3 Side Wall of Apparatus 2 Loading Platform (Paper Feeding Section) 4 Elastic Member 11a Pressing Member

Claims (2)

[Claims] 1. An image forming apparatus that presses a friction pad onto the peripheral surface of a paper feed roller in contact with a transfer paper to feed paper one by one, and an apparatus side wall with a support shaft provided on the paper feed end side as a center. Is provided so that a plurality of transfer sheets can be stacked on the side wall, and the rotation fulcrum of the friction pad is aligned with the pivot of the side wall. Forming device 2. An image formed by forming a side wall of an apparatus around a support shaft provided on a side of a sheet feeding end so as to be openable, and forming a sheet feeding portion on which the one or a plurality of transfer sheets can be stacked. In the forming apparatus, an elastic member that applies an elastic force to the paper feed unit toward the paper feed roller, and a fulcrum that swings the paper feed unit toward and away from the paper feed roller are provided on the support shaft. The transfer sheets are sequentially arranged along the side wall open end side so that a large number of transfer sheets can be stacked on the sheet feeding section, and the sheet feeding section is pressed against the apparatus main body facing the side wall. An image forming apparatus is provided with a pressing member, and the paper feeding unit is folded by the pressing member against the elastic force when the side wall is closed and folded toward the side wall so as to be stored.