JP3441569B2 - Paper feeder of image forming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device of an image forming apparatus such as a copying machine, a facsimile and a laser beam printer.

[0002]

2. Description of the Related Art The present invention has been made for the purpose of solving the problems of the "paper feed guide device for an image forming apparatus" described in Japanese Patent Laid-Open No. 4-317930, which was previously proposed by the present applicant. Is.

The above apparatus comprises an image forming section, a sheet feeding cassette disposed below the image forming section, and a sheet guide extending vertically from the tip of the sheet feeding cassette toward the image forming section. And a large-sized paper feeding device whose side surfaces are arranged opposite to each other with a predetermined gap in the paper guide, and a paper feeding passage formed between the paper guide and the side surface of the large paper feeding device. Is characterized by. Further, this apparatus is characterized in that a fulcrum portion for rotatably holding a large-sized sheet feeding device with a vertical rotation axis is provided near one rear side of the sheet guide. Furthermore, this device is characterized in that a fulcrum portion for rotatably holding a large-sized paper feeding device with a vertical rotation axis is provided near one side on the back side and one side on the front side of the paper guide. I am trying.

According to this apparatus, the number of paper guides can be reduced and the supporting structure for supporting the paper guides can be simplified. Further, according to this device, the rigidity of the side surface of the large-sized paper feeding device is higher than the rigidity of the single paper guide,
Since the support strength of the transport rollers can be increased and the contact pressure between the pair of transport rollers can be maintained above a certain level, it is possible to reduce the occurrence of paper misfeeds and jams. Further, according to this device, the paper path of the paper guide can be opened by rotating the large paper feeding device with respect to the main body of the device, so that the jammed paper jammed in the paper guide can be easily removed. .

[0005]

By the way, in the above-mentioned conventional apparatus, as shown in FIG.
A paper guide (hereinafter referred to as a transfer paper guide unit 20) is provided with a vertical axis on the back side of the paper feed unit 100 as a fulcrum.
The sheet feeding unit 100 is supported by the image forming apparatus main body 300 so as to be openable and closable with a transfer sheet path of 0) as a boundary. However, in this type of paper feeding device, the back side of the paper feeding unit 100 can be supported by a supporting means such as a hinge with a vertical axis as a fulcrum, while the front side of the paper feeding unit 100 is As shown in FIG. 19, there is a high possibility that the sheet feeding unit itself will be deformed due to its own weight and the weight of a large amount of the transfer sheets 1 loaded on the sheet feeding table 101.

That is, as shown in FIG. 19, a supporting member 4 for supporting the transfer paper guide means 200 of the paper feeding unit 100 from below is provided on the image forming apparatus main body 300 side, and the paper feeding unit 100 is supported by this supporting member 400. When it is configured to support the sheet feeding unit 100, as described above.
Due to its own weight and the weight of the transfer sheet 1, only the front side of the sheet feeding unit 100 is twisted in the direction of arrow a. Therefore, in this paper feeding device, the image forming apparatus main body 300 and the paper feeding unit 1
Since the gap of the guide plate forming the paper feeding path of the transfer paper 1 between 0 and 00 is wide in the front upper part and narrow in the front lower part, the pressing force (contact pressure) of each of the transport rollers 201 and 301 is reduced. The balance between the front and rear becomes unbalanced, and the transfer sheet 1 may be obliquely fed. Also, the sheet feeding path is narrowed at the front lower side to easily cause paper jam, and the sheet feeding path is widened at the front upper side. There is a possibility that erroneous detection of the sensor may occur. The inventions of claims 1 and 5 are made in view of the above-mentioned points, and an object thereof is to eliminate the twist on the front side of the sheet feeding unit when the sheet feeding unit is closed, and to perform the transfer. An object of the present invention is to provide a sheet feeding device of an image forming apparatus that can prevent skewed feeding of paper, paper jamming, and erroneous detection of a paper sensor.

However, it is difficult to completely prevent the oblique feeding of the transfer sheet only by eliminating the twist on the front side of the sheet feeding unit when the sheet feeding unit is closed.
That is, in this paper feeding device, between the gap of the guide plate on the back side of the paper feeding unit 100 when the paper feeding unit is closed and the gap of the guide plate on the front side of the paper feeding unit 100 when the paper feeding unit is closed. If there is a difference, the contact pressure of the conveyance roller on the back side and the contact pressure of the conveyance roller on the front side are different from each other, so that the transfer sheet is obliquely fed. Here, the back gap of the paper feeding unit 100 is kept at a predetermined interval by the supporting member that rotatably supports the paper feeding unit 100, so that the gap of the front guide plate is the back gap. By controlling the closing position on the front side of the paper feeding unit when the paper feeding unit is closed, the oblique feeding of the transfer paper can be eliminated. The invention according to claim 2 is made in view of this point, and an object of the invention is to provide an image forming apparatus capable of accurately controlling the closing position on the front side of the paper feeding unit when the paper feeding unit is closed. To provide a sheet feeding device.

On the other hand, in this type of sheet feeding device, normally, the sheet feeding unit 100 is attached to the main body 300 of the image forming apparatus.
A detection member for detecting whether it is in the open state or the closed state is provided. However, as described above, when the sheet feeding unit 100 is twisted when closed, depending on the mounting position of the detection member, the sheet feeding unit 100 can be fed without being completely closed. Paper feed unit 10
An erroneous detection occurs such that the paper feed is prohibited even though 0 is closed. Therefore, in this type of paper feeding device,
It is desired to dispose a detection member so as to prevent erroneous detection and accurately detect the open / closed state of the sheet feeding unit. The invention according to claim 3 is made in view of this point, and an object thereof is to provide a sheet feeding device of an image forming apparatus capable of accurately detecting an open / closed state of a sheet feeding unit. is there.

In the above-mentioned paper feeding apparatus, as a method of eliminating the twist of the paper feeding unit 100 when the paper feeding unit is closed, the paper feeding unit is closed and the engaging portion of the image forming apparatus main body 300 is fed. When the engaged portions of the paper unit 100 are engaged with each other without any gap and the vertical position on the front side of the paper feeding unit 100 is restricted, the engaged portions are engaged with the engaged portions. The operability at that time may be deteriorated, and the engagement portion may be significantly worn due to repeated opening and closing of the paper feeding unit 100. The invention according to claim 1 is made in view of this point, and an object thereof is an image forming apparatus excellent in operability of an engaging portion when a paper feeding unit is opened and closed and excellent in abrasion resistance. The purpose of the present invention is to provide a paper feeding device.

As described above, in this paper feeding device, when the paper feeding unit is closed, the unit vertical position regulating member for regulating the vertical position of the front side of the paper feeding unit 100 with respect to the image forming apparatus main body 300 is provided. The twisting on the front side of the sheet feeding unit can be eliminated, and the unit vertical position regulating member is provided with a unit closing position regulating member for regulating the front side closing position of the sheet feeding unit 100 when the sheet feeding unit is closed. As a result, it is possible to completely prevent the oblique feeding of the transfer paper. However, when the unit vertical position restricting member and the unit closed position restricting member are individually arranged, there is a problem that the structure of the device becomes complicated. The invention according to claim 4 is made in view of this point, and an object thereof is a structure in which the unit vertical position restricting member and the unit closed position restricting member are configured by one member. An object of the present invention is to provide a sheet feeding device of an image forming apparatus that can be simplified.

By the way, as a method of keeping the gap between the image forming apparatus main body 300 and the paper feeding unit 100 constant when the paper feeding unit is closed, a convex portion as a spacer is provided between the image forming apparatus main body 300 and the paper feeding unit 100. When the sheet feeding unit 100 is configured to intervene, the projecting portion or a member corresponding to the projecting portion may be damaged by the impact when the sheet feeding unit 100 is closed vigorously. The invention according to claim 5 is made in view of this point, and an object thereof is to provide a sheet feeding device of an image forming apparatus capable of mitigating an impact when the sheet feeding unit is closed. .

[0012]

The invention according to claim 1 is
In order to solve the above problems, stack transfer paper
The paper feeding unit has a descending paper feeding base and a transfer paper guiding means for conveying the transfer paper fed from another paper feeding port to the downstream, and the paper feeding unit is provided. In a paper feeding device of an image forming apparatus, the paper feeding unit is supported to be openable and closable with respect to the main body of the image forming apparatus with a transfer paper path of the transfer paper guiding means as a fulcrum with an axis line in the vertical direction of the side as a fulcrum. A vertical direction on the front side of the sheet feeding unit with respect to the image forming apparatus main body, by engaging the image forming apparatus main body and the front side portion of the sheet feeding unit with each other without a gap in the closed state of the sheet feeding unit. A unit vertical position regulating member for regulating the position of is provided, and a roller for rollingly contacting and engaging the engaged portion is provided in the engaging portion of the unit vertical position regulating member.

According to a second aspect of the present invention, in order to solve the above-mentioned problems, the unit vertical position regulating member regulates a closing position on the front side of the paper feeding unit when the paper feeding unit is closed. A unit closing position regulating member is provided.

According to a third aspect of the present invention, in order to solve the above problems, the opening / closing state of the sheet feeding unit with respect to the main body of the image forming apparatus is detected by operating by the engaging / disengaging operation of the unit closing position regulating member. A unit opening / closing detection member is provided.

In order to solve the above problems, the unit vertical position restricting member and the unit closed position restricting member are integrally constituted by a permanent magnet and a magnetic body.

In order to solve the above-mentioned problems, a fifth aspect of the present invention is directed to a paper feed table on which transfer papers are stacked and moved up and down, and a transfer paper fed from another paper feed port to the downstream side. There is provided a paper feed unit in which transfer paper guide means for transporting is integrated, and a transfer paper path of the transfer paper guide means is set as a boundary with a vertical axial line on the back side of the paper feed unit as a fulcrum. ,
In a sheet feeding device of an image forming apparatus in which the sheet feeding unit is openably and closably supported with respect to the image forming apparatus main body, the sheet feeding unit is closed at a position in front of the image forming apparatus main body and the sheet feeding unit. The unit vertical position regulating member for regulating the vertical position of the front side of the sheet feeding unit with respect to the image forming apparatus main body is provided while the unit vertical position regulating member is provided. A convex portion is provided on the lower portion on the front side to secure a gap between the main body of the image forming apparatus and the sheet feeding unit when the paper feeding unit is closed, and a feeding portion is provided above the convex portion. A unit closing position restricting member for restricting the front side closing position of the paper feeding unit when the paper unit is closed is provided, and the convex portion is fixed to the image forming apparatus main body or the paper feeding unit. And rigid bodies, a structure consisting of an elastic member which is coated on the rigid as further protrude from and projecting exit surface to expose the protruding surface of the rigid body.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows the overall configuration of an image forming apparatus in which the present invention is implemented. In FIG. 1, an image forming apparatus main body 300 has a sheet feed table 101 on which a transfer sheet 1 is loaded and moved up and down, and a transfer sheet 2 for transferring a transfer sheet 2 fed from another sheet feeding port to a downstream side. The paper feed unit 100 that is integrated with the paper guide unit 200 is the paper feed unit 100.
The image forming apparatus main body 300 is separated from the transfer paper path of the transfer paper guide means 200 by using the vertical axis on the back side of the paper as a fulcrum.
It is supported to be openable and closable.

On the paper feed table 101, side fences 102 for positioning both sides of the transfer paper 1, end fences 103 for positioning the rear end of the transfer paper 1, an upper cover 104,
A paper end sensor 105 and the like are provided, and a large amount (about 1000 sheets in this embodiment) of transfer papers 1 at a time.
Is configured to be loaded.

The transfer paper guide means 200, as shown in FIG. 1, has a guide plate 202 and a plurality of conveying rollers 20.
1 and a sheet sensor 203, the conveyance roller 201 is provided with a bearing (not shown) by a spring (not shown) with respect to the conveyance roller 301 that is driven and rotated and is disposed at a facing portion on the image forming apparatus main body 300 side. Each of them is driven and rotated by being pressurized.

The paper feeding unit 100 is normally closed with respect to the image forming apparatus main body 300, and in this state, the transfer paper 1 stacked on the paper feeding table 101 or the image forming apparatus main body 300. The transfer paper 2 accommodated in the paper feed tray 3 disposed inside is the paper feed unit 100.
The call roller 106 and the paper feed roller 107 on the side, or the call roller 302 and the paper feed roller 303 on the side of the image forming apparatus main body 300, and the conveyance rollers 201 and 301 of the paper feed unit 100, are arranged on the downstream side of the transfer paper path. It is conveyed to the registration roller 5 provided.

The transfer sheet 1 (or 2) conveyed to the registration roller 5 and waiting is transferred with an image by a well-known image forming means including a photoconductor 6 and a developing device 7, and is ejected as a copy to the outside of the machine. It

On the other hand, the paper sensor 203 arranged in the transfer paper path of the transfer paper guide means 200 checks whether or not the transfer paper 2 fed from the paper feed tray 3 is conveyed at a predetermined timing. If it is determined here that the transfer paper 2 is conveyed later than the set conditions and the transfer paper 2 is not fed or a jam occurs, as shown in FIG. Open 100. As is clear here, in the paper feeding device of this image forming apparatus, when a transfer paper jam or the like occurs, the paper feeding unit 100
Since the transfer paper path can be exposed by opening, the jammed paper or the like jammed in the transfer paper path can be easily removed.

However, as described above, in the structure in which the sheet feeding unit 100 is openably and closably supported with respect to the image forming apparatus main body 300 with the vertical axis line on the back side of the sheet feeding unit 100 as a fulcrum. As described above, only the front side of the sheet feeding unit 100 is twisted in the direction of arrow a due to the weight of the sheet feeding unit 100 and the weight of the transfer sheet 1. Therefore, in this paper feeding device, the gap of the guide plate forming the paper feeding path of the transfer paper 1 between the image forming apparatus main body 300 and the paper feeding unit 100 is wide in the front upper part and narrow in the front lower part. Therefore, each of the transport rollers 201,
The balance before and after the pressing force (contact pressure) of 301 is unbalanced, and the transfer sheet 1 is obliquely fed. Also, the sheet feeding path is narrowed at the lower front side, which easily causes a paper jam. Then, there is a possibility that the paper feed path becomes wide and erroneous detection of the paper sensor may occur.

Therefore, according to the first aspect of the invention, as shown in FIG.
Unit upper and lower position regulating member for regulating the position of the front side of the sheet feeding unit 100 with respect to the image forming apparatus main body 300 in the vertical direction by engaging the sheet feeding unit 100 in the front side portion of 00 with no space therebetween. It is assumed that 400 is provided.

That is, the unit vertical position restricting member 400 of the embodiment shown in FIG. 2 has a U-shaped concave portion 401 having a width B provided on the front side surface of the guide plate 202 of the transfer paper guide means 200. It is composed of a convex-shaped supporting member 402 having a width A that engages with the concave portion 401 without a vertical gap. Here, the support member 402 is the image forming apparatus main body 3
00, and the upper and lower corners of the support member 402 have tapered portions for facilitating engagement with the recess 401 when the sheet feeding unit 100 is closed in the direction of the arrow in FIG. Are formed.

According to this embodiment, the relationship between the width A of the support member 402 of the unit vertical position restricting member 400 and the width B of the recess 401 is A <B, and the difference is set to be as small as possible. Therefore, when the paper feeding unit 100 is closed, that is, when the recess 401 and the support member 402 are engaged with each other, the play (rattle) becomes small, and the weight of the paper feeding unit 100 and the weight of the transfer sheet 1 in the unit closed state. Therefore, the twist of the sheet feeding unit 100 as shown in FIG. 19 is eliminated. Further, in this embodiment, the larger the overlap dimension C of the engaging portion between the supporting member 402 of the unit vertical position restricting member 400 and the recess 401, the greater the effect of preventing the sheet feeding unit 100 from twisting relative to the image forming apparatus main body 300. Is big.

Next, the invention according to claim 2 will be described. As described above, it is difficult to completely prevent the oblique feeding of the transfer sheet only by eliminating the twist on the front side of the sheet feeding unit when the sheet feeding unit is closed. However, the gap on the back side of the paper feeding unit 100 is
Since 0 is rotatably supported by a supporting member, the gap between the guide plates on the front side is equal to the gap on the back side. By regulating the closing position on the side, the oblique feeding of the transfer paper can be eliminated.

Therefore, in the second aspect of the invention, the unit vertical position restricting member 400 is provided with the unit closing position restricting member 500 for restricting the closing position on the front side of the paper feeding unit 100 when the paper feeding unit is closed. .

As shown in FIGS. 3 to 5, the unit closing position restricting member 500 according to the present embodiment includes a lock pin 501 which is planted (or integrally formed) in the supporting member 402 of the unit vertical position restricting member 400. Paper feeding unit 1
Support shaft 502 planted in the side plate 108 of 00, lock arm 503 rotatably supported by the support shaft 502,
The arm portion of the lock arm 503 is provided with a lock pin 501.
Lock arm 5 has a tendency to rotate in the direction of engaging with the groove portion of the lock arm 5.
03 for biasing the lock arm 50 and the lock arm 50.
3 and a release lever 505 integrated with a lock arm 503 for releasing the engagement with the lock pin 501.

The unit closing position regulating member 500 is
When the paper feeding unit 100 is closed with respect to the image forming apparatus main body 300, as shown in FIGS.
The arm portion of the lock arm 503 engages with the groove portion of the lock pin 501 by the urging force of the sheet feeding unit 100.
Is locked to regulate the closing position of the front side of the paper feeding unit 100 when the paper feeding unit is closed. here,
The lock arm 503 and the lock pin 501 are arranged such that when the arm portion of the lock arm 503 is engaged with the groove portion of the lock pin 501, the gap of the guide plate on the front side between the sheet feeding unit 100 and the image forming apparatus main body 300 is small. , Is set in advance so as to be equal to the gap on the back side. Further, when unlocking the sheet feeding unit 100 by the unit closing position regulating member 500, as shown in FIG. 5, the release lever 505 is rotated against the tendency of the lock arm 503 to rotate by the spring 504. Then, the engagement between the arm portion of the lock arm 503 and the groove portion of the lock pin 501 is released.

Next, the invention according to claim 3 will be described. In this type of paper feeding device, the image forming apparatus main body 3 is usually used.
00, a detection member for detecting whether the sheet feeding unit 100 is in the open state or the closed state is provided. As described above, the sheet feeding unit 100 in the closed state is provided. If the sheet is twisted, depending on the mounting position of the detection member, the sheet feeding unit 1
There are erroneous detections such that the paper feeding is enabled in a state where 00 is not completely closed, or the paper feeding is prohibited even though the paper feeding unit 100 is closed.

Therefore, according to the third aspect of the invention, the sheet feeding unit 1 for the image forming apparatus main body 300 is operated by the engaging / disengaging operation of the unit closing position regulating member 500.
Unit open / close detection member 600 for detecting the open / closed state of 00
Is provided. The unit opening / closing detection member 600 of this embodiment is composed of a micro switch that is turned on / off by the lock pin 501 of the unit closing position regulating member 500 described above, and as shown in FIG. On the other hand, when the paper feeding unit 100 is in the closed state, the tip of the lock pin 501 presses the micro switch, while the paper feeding unit 100 is moved toward the image forming apparatus main body 300 as shown in FIG. In the open state, the tip of the lock pin 501 is separated from the micro switch to detect the open / closed state of the sheet feeding unit 100.

In this way, the unit closing position regulating member 5
By detecting the open / closed state of the sheet feeding unit 100 at the engagement / disengagement position of 00, the unit opening / closing detection member 600 is not affected by the twist of the sheet feeding unit 100 when closed.
Is accurately operated by opening and closing the paper feeding unit 100.

Next, the invention according to claim 1 will be further described. As shown in FIG. 2, as a method of eliminating the twist of the sheet feeding unit 100 when the sheet feeding unit is closed, the sheet feeding unit is closed and the sheet is fed to the engaging portion of the image forming apparatus main body 300. Unit 10
0 of the paper feed unit 10 by engaging the engaged portions without gaps.
When the vertical position on the front side of 0 is regulated, the operability at the time of engaging the engaged portion with the engaging portion may be deteriorated, and the paper feeding unit 100 may be deteriorated. The wear of the engaging portion due to repeated opening and closing also becomes significant.

Therefore, according to the first aspect of the present invention, as shown in FIG. 8, the engaging portion of the support member 402 of the unit vertical position restricting member 400 engaging with the concave portion 401 of the guide plate 202 is provided with respect to the concave portion 401. The roller 403 is arranged so as to be in rolling contact with and engaged with. In this case, the upper roller 4
Dimension A from the upper end of 03 to the lower end of the lower roller 403
Is set to be equal to the width A of the support member 402 shown in FIG. Further, it is necessary to provide at least two rollers 403 on the upper side and one roller 403 on the lower side, respectively, as in the embodiment of FIG.
It is desirable to prevent zero twist.

Next, the invention according to claim 4 will be described. By the way, the above-mentioned unit vertical position regulating member 40
When 0 and the unit closing position regulating member 500 are individually arranged, there is a problem that the structure of the device becomes complicated. Therefore, in the invention according to claim 4, the unit vertical position restricting member 400 and the unit closed position restricting member 500 are configured by one member to simplify the structure. That is, in the embodiment shown in FIG. 9, a member having both the function of the unit vertical position restricting member 400 and the function of the unit closed position restricting member 500 is a permanent magnet 451.
And a steel plate 452 made of a magnetic material arranged so as to sandwich both sides of the permanent magnet 451 and these permanent magnets 451.
And a resin member 453 that covers the periphery of the steel plate 452.

In this embodiment, the image forming apparatus main body 300
The upper and lower positions of the sheet feeding unit 100 are regulated by the resin member 453 engaging with the concave portion 401 of the guide plate 202, and the closed position of the sheet feeding unit 100 with respect to the image forming apparatus main body 300 is regulated. The guide plate 202 is attracted to the steel plate 452 by the magnetic force of the permanent magnet 451. Therefore, according to the present embodiment, the complicated unit closing position restricting member 500 having the configuration including the lock pin 501, the lock arm 503, and the like becomes unnecessary.

Next, the invention according to claim 5 will be described. The present invention provides another means for eliminating the twist of the sheet feeding unit 100 when the unit is closed,
An example thereof is shown in FIG. In FIG. 10, the vertical positioning of the sheet feeding unit 100 with respect to the image forming apparatus main body 300 is performed in the same manner as in the conventional example shown in FIG.
This is performed by mounting a U-shaped cutout portion 204 provided on the front side of the guide plate 202 of the sheet feeding unit 100 on the support member 4 provided in the image forming apparatus main body 300.

Further, in this embodiment, the paper feeding unit 100
The image forming apparatus main body 300 and the paper feeding unit 100 when the paper feeding unit is closed are provided on the lower front side of the guide plate 202.
By providing a convex portion 700 for securing a gap on the front side lower part of the sheet feeding unit 100, the lower portion of the sheet feeding unit 100 is restricted and prevented from being twisted as shown in FIG.
A unit closing position restricting member 500 shown in FIGS. 11 to 13 for restricting the closing position on the front side of the paper feeding unit 100 when the paper feeding unit is closed is provided at a portion above the convex portion 700 to supply the paper. While correcting the opening of the upper part of the paper unit 100 as shown in FIG. 19, the rotation of the paper feeding unit 100 is locked upward by the unit closing position restricting member 500. The unit closing position restricting member 500 in this embodiment has the same structure as the unit closing position restricting member 500 shown in FIGS. 3 to 5.

According to this embodiment, as described above, first,
The vertical positioning of the paper feeding unit 100 when the unit is closed is performed by the engagement of the support member 4 and the cutout portion 204, and then the front side of the image forming apparatus main body 300 and the paper feeding unit 100 by the convex portion 700. By securing the lower gap, the unit closing position regulating member 5 is regulated while regulating the rotation of the sheet feeding unit 100 in the twisting direction.
00, by locking the rotation of the paper feeding unit 100 upward, the twist of the paper feeding unit 100 can be corrected, so that the paper feeding unit 100 when the unit is closed.
Can be eliminated, and the upper and lower gaps of the guide plate 202 can be kept uniform. Here, the higher the disposition position of the unit closing position restricting member 500 with respect to the convex portion 700, the more effectively the gap between the upper and lower sides of the guide plate 202 is maintained.

Next, the invention according to claim 5 will be further described. By the way, the image forming apparatus main body 300 and the paper feeding unit 100 when the paper feeding unit is closed.
As a method of keeping a constant gap between the image forming apparatus main body 300 and the paper feeding unit 100, as shown in FIG.
When the convex portion 700 serving as a spacer is interposed between the convex portion 700 and the convex portion, the convex portion 700 or a member corresponding to the convex portion 700 is damaged by the impact when the paper feeding unit 100 is vigorously closed. There is fear. Therefore, claim 5
In the described invention, as in the embodiment shown in FIGS. 14 to 17, the above-mentioned convex portion 700 is provided with a rigid body 701 fixed to the guide plate 202 of the sheet feeding unit 100 and made of metal or hard resin, and this rigid body 701. The elastic member 702 is made of rubber, sponge, or the like and is covered with the rigid body 701 so that the protruding surface of 701 is exposed and further protrudes from the protruding surface.

Therefore, in this embodiment, as shown in FIG. 16, the elastic body 702 is projected more than the projecting dimension D of the rigid body 701 before the paper feeding unit 100 is closed with respect to the image forming apparatus main body 300. Since the dimension E is set larger, the impact when the sheet feeding unit 100 is closed is softened by the deformation of the elastic body 702 as shown in FIG. Further, since the rigid body 701 is not deformed when the sheet feeding unit 100 is closed, the gap between the image forming apparatus main body 300 and the guide plate 202 is the rigid body 7.
Positioned by a protrusion dimension D of 01.

[0043]

As described above, according to the first aspect of the present invention, the image forming apparatus main body and a part of the paper feeding unit are
Since they are engaged so as not to create a gap in the vertical direction, the front side of the paper feeding unit is not twisted by the weight of the paper feeding unit or the weight of the transfer paper, and the balance of the pressing force before and after the transport roller is deteriorated. It is possible to prevent the oblique feeding of the transfer paper, the transfer paper jam due to the narrow gap of the lower transfer paper path, and the erroneous detection of the paper sensor due to the widening of the upper transfer paper path. According to the first aspect of the invention, the image forming apparatus main body and the paper feeding unit are
Since a roller is interposed in the engaging portion of the member that engages so as not to create a gap in the vertical direction, the operability of the sheet feeding unit when the sheet feeding unit is closed can be improved and wear of the engaging portion can be reduced. Therefore, the durability of the device can be improved.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the unit vertical position regulating member for regulating the vertical position of the sheet feeding unit regulates the closed position of the sheet feeding unit. Since the unit closing position regulating member for controlling the position is provided, the position of the sheet feeding unit in the vertical direction can be regulated at the position where the position can be regulated most accurately, and the gap of the transfer sheet path between the image forming apparatus main body and the sheet feeding unit can be controlled. Can be maintained evenly in the front, back, front, and rear, and oblique feeding of the transfer paper can be reliably prevented.

According to the invention of claim 3, claim 1,
In addition to the effect of the invention described in 2, the unit closing position regulating member for regulating the closing position of the sheet feeding unit disposed in the unit vertical position regulating member for regulating the vertical position of the sheet feeding unit is operated. Since a unit open / close detection member that detects the open / closed state of the paper feeding unit is provided at the position, the open / closed state of the paper feeding unit can be detected at the part that can most accurately regulate the closed position of the paper feeding unit. False detection of the detection member can be prevented.

According to the invention of claim 4, in addition to the effect of the invention of claim 2, a unit vertical position restricting member for restricting the vertical position of the paper feeding unit and a closed position of the paper feeding unit are restricted. Since the unit closing position regulating member for doing so is composed of one member utilizing magnetic force, the device can be simplified.

According to the invention of claim 5, the unit is closed.
Support the vertical positioning of the paper feeding unit when the chain
This is done by the engagement of the holding member and the notch, and the projection makes the image
Make sure the gap between the main body of the forming device and the paper feeding unit is
Keep the rotation of the paper feed unit in the twisting direction.
However, due to the unit closing position regulation member,
Lock the rotation of the above to prevent twisting of the paper feeding unit.
Since it can be corrected, when the unit is closed
Eliminate twisting and make the gap above and below the guide plate uniform
Can maintain and balance the pressure before and after the transport roller
Skew of the transfer paper due to deterioration of the
Transfer paper jam due to the narrowing of the gap and the upper roll
Occurrence of false detection of paper sensor due to spread of paper path
Can be prevented.

According to the fifth aspect of the present invention, the above-mentioned convex portion is composed of a rigid body and an elastic member, and the rigid body projects before the paper feed unit is closed with respect to the image forming apparatus main body. Since the protrusion size of the elastic body is set larger than the size, the impact when the paper feeding unit is closed can be softened by the deformation of the elastic body. Alternatively, it is possible to prevent the member corresponding to the convex portion from being damaged. Further, since the rigid body is not deformed when the sheet feeding unit is closed, the gap between the image forming apparatus main body and the guide plate can be positioned by the projecting dimension of the rigid body.

[Brief description of drawings]

FIG. 1 is a schematic front view showing the overall configuration of a sheet feeding device of an image forming apparatus in which the present invention is implemented.

FIG. 2 is a schematic front view of an embodiment of the invention described in claim 1.

FIG. 3 is a schematic plan view showing a locked state of the unit closing position restricting member in the embodiment of the invention as set forth in claim 2;

FIG. 4 is a schematic side view showing a locked state of the unit closing position restricting member in the embodiment of the invention as set forth in claim 2;

FIG. 5 is a schematic side view showing the unlocked state of the unit closing position restricting member in the embodiment of the invention as set forth in claim 2;

FIG. 6 is a schematic front view showing an operating state of a unit open / close detection member in the embodiment of the invention as set forth in claim 3;

FIG. 7 is a schematic front view showing a non-operating state of the unit open / close detection member in the embodiment of the invention as set forth in claim 3;

FIG. 8 is a schematic front view showing an engaged state of the unit vertical position restricting member in the embodiment of the invention as set forth in claim 1;

FIG. 9 is a schematic front view showing an engaged state of a unit vertical position restricting member and a unit closed position restricting member in an embodiment of the invention as set forth in claim 4;

FIG. 10 is a schematic front view of an embodiment of the invention described in claim 5.

FIG. 11 is a schematic plan view showing a locked state of the unit closing position restricting member in the embodiment of the invention as set forth in claim 5;

FIG. 12 is a schematic side view showing a locked state of the unit closing position restricting member in the embodiment of the invention as claimed in claim 5;

FIG. 13 is a schematic side view showing the unlocked state of the unit closing position restricting member in the embodiment of the invention as claimed in claim 5;

FIG. 14 is a schematic front view of an embodiment of the invention described in claim 5;

FIG. 15 is a schematic perspective view of a convex portion in the embodiment of the invention described in claim 5;

FIG. 16 is a schematic front view of the convex portion when the sheet feeding unit according to the embodiment of the invention described in claim 5 is opened.

FIG. 17 is a schematic front view of the convex portion when the sheet feeding unit is closed according to the embodiment of the invention described in claim 5;

FIG. 18 is a schematic perspective view showing a sheet feeding device of a conventional image forming apparatus.

FIG. 19 is a schematic front view of a sheet feeding device of a conventional image forming apparatus.

[Explanation of symbols]

1,2 transfer paper 3 paper trays 4 Support members 5 Registration roller 6 photoconductor 7 Developer 100 paper feed units 101 paper feed table 102 side fence 103 end fence 104 top cover 105 Paper end sensor 106,302 calling roller 107,303 paper feed rollers 108 Side plate 200 Transfer paper guide means 201,301 Conveyor roller 202 guide plate 203 Paper sensor 204 Notch 300 Image forming apparatus main body 400 unit vertical position control member 401 recess 402 support member 451 permanent magnet 452 steel plate 453 resin member 500 Unit closing position control member 501 lock pin 502 spindle 503 lock arm 504 spring 505 Release lever 600 Unit open / close detection member 700 convex 701 rigid body 702 elastic member

Continuation of the front page (56) Reference JP-A-4-317930 (JP, A) JP-A-3-88636 (JP, A) JP-A-64-38328 (JP, A) JP-A-2-132035 (JP , A) JP 4-28633 (JP, A) JP 62-83940 (JP, A) Actual flat 2-61846 (JP, U) Actual flat 1-108549 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65H 3/00 310 B65H 3/68 G03G 15/00 516

Claims (5)

(57) [Claims] 1. A paper feed table on which transfer papers are loaded and moved up and down, and a transfer paper guide means for conveying the transfer papers fed from other paper feed ports to the downstream are integrated. A sheet feeding unit is provided, and with a vertical axis line on the back side of the sheet feeding unit as a fulcrum, with a transfer sheet path of the transfer sheet guide means as a boundary,
In a sheet feeding device of an image forming apparatus in which the sheet feeding unit is openably and closably supported with respect to the image forming apparatus main body, the sheet feeding unit is closed at a position in front of the image forming apparatus main body and the sheet feeding unit. And a unit vertical position regulating member for regulating the vertical position of the front side of the sheet feeding unit with respect to the image forming apparatus main body in a closed state, and the engaging portion of the unit vertical position regulating member. To the engaged part
A sheet feeding device for an image forming apparatus, which is provided with rollers that are in rolling contact with and engage with each other . 2. The unit vertical position restricting member is provided with a unit closing position restricting member for restricting a front side closing position of the paper feeding unit when the paper feeding unit is closed. 1. A sheet feeding device of the image forming apparatus described in 1. 3. A unit opening / closing detecting member which is operated by an engaging / disengaging operation of the unit closing position restricting member to detect an opening / closing state of the sheet feeding unit with respect to the image forming apparatus main body. A sheet feeding device of the image forming apparatus described. 4. The unit vertical position restricting member and the unit.
The knit closing position regulating member is made up of a permanent magnet and a magnetic body.
The sheet feeding device of the image forming apparatus according to claim 2, wherein the sheet feeding device is integrally configured . 5. A paper feed table for stacking transfer paper and ascending / descending.
And transfer the transfer paper fed from the other paper feed port to the downstream.
And a transfer paper guide means for
It has a dot and the axis of the vertical rear side of the paper feed unit
As a fulcrum, with the transfer paper path of the transfer paper guide means as a boundary,
The paper feeding unit can be freely opened and closed with respect to the main body of the image forming apparatus.
In the paper feeding device of the image forming apparatus that is supported,
At the front side of the image forming apparatus main body and the paper feeding unit,
When the paper units are closed, they engage with each other to form the image.
The vertical direction on the front side of the paper feeding unit with respect to the apparatus main body
A unit vertical position control member that controls the position
Before the image forming apparatus main body or the paper feeding unit
The image forming apparatus at the bottom of the side when the paper feeding unit is closed
Securing a gap at the lower front side between the main body and the paper feeding unit
And a portion above the protrusion.
In front of the paper feeding unit when the paper feeding unit is closed
Unit closing position regulation part to regulate the closing position on the side
Material is provided, and the convex portion is provided so that the image forming apparatus body or the paper feeding unit is
Exposing a rigid body fixed to the base and a protruding surface of the rigid body, and
The rigid body was coated so as to project further than the projecting surface.
Sheet feeding apparatus of images forming device characterized by comprising an elastic member.