JP2002356247A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of smoothly feeding paper without inclination or flapping of recording material even if an opening of a paper feeding guide passage of recording material is set as wide as possible for reducing paper feeding resistance in a device provided with plural paper feeding parts such as a paper feeding cassette, a manual paper feeding part and an optional paper feeding unit. SOLUTION: A guide wall for leading recording material to a register guide passage with forcedly bending is formed on one side in a reversing paper feeding pass. A designated part of a first guide wall which a tip of the recording material fed from a first paper feeding part gets into contact with is dent to form a wide passage opening. A second guide wall part positioned in the downstream of the first guide wall part is formed into a shape that width gets gradually narrower as it goes from the wide passage to inlet end of the register guide passage. A third guide wall part from a paper feeding opening position to the first guide wall part is formed in a shape that width of the passage of the recording material from the second paper feeding part gets gradually wider.

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 which is mainly applied as a printer, a copying machine, a facsimile or a multifunction machine thereof, and which can selectively feed recording materials of different sizes. The present invention relates to an invention applied as an image forming apparatus provided with a paper feeding unit.

[0002]

2. Description of the Related Art Conventionally, in printers and copiers,
A4 A manual paper feed unit is provided separately from the paper cassette in which standard paper is stored, so that postcards and recording paper of a type different from the recording paper stored in the paper cassette can be printed. It is configured to enable copying. Further, in order to reduce the size and flattening of the image forming apparatus, a single and flat sheet feeding cassette to be housed in the main body of the apparatus is provided, and an optional feeding cassette for storing recording materials of other sizes and / or a large number of recording materials is provided. There is also a system in which a paper unit can be mounted according to a user's request. Further, an apparatus has been proposed in which the sheet cassette is formed of a universal cassette so that the size of the recording material stored in the recording material storage section of the apparatus main body can be changed.

On the other hand, in a photosensitive drum for transferring a toner image onto the recording material, a toner image is formed in accordance with the size of a recording sheet to be fed. When a recording material having a different size from the paper portion is selectively fed to the transfer position of the photosensitive drum, the photosensitive material must be detected in advance by the paper feeding unit before the photosensitive material is detected. In some cases, the size of the toner image printed on the drum and the size of the recording material may differ. In such a case, the remaining toner image after printing adheres to the recording material from the photosensitive drum to the transfer roller side, and the next recording is performed. This not only contaminates the back surface of the material, but also damages the photosensitive drum.

In order to solve such a drawback, a size detection sensor for detecting the size of the recording material is provided for each size. However, such a configuration complicates the configuration and guides the sensor signal to a substrate on the apparatus body side. And other harnesses are routed inside the apparatus, and the harnesses and the like may be damaged. Further, a sensor for detecting the absence of paper of the recording material must also be attached to the cassette on the option unit side together with the paper feed cassette, so that the configuration is complicated and the wiring of the harness is further complicated.

Japanese Utility Model Application No. 4-11 filed by the present applicant
As shown by reference numeral 567, a sheet cassette is configured to be able to be stored in a cassette storage section of the apparatus main body, and an optional sheet supply unit is disposed on the apparatus bottom side on the lower side of the cassette, and a recording material storage section of the sheet cassette is provided. A vertical guide path for guiding the recording material fed from the optional unit to the feed roller or the registration roller entrance end while inverting the recording material is provided between the front and rear walls. In such a vertical guide path, an air gap between conveying ribs forming the guide path is set as wide as possible in order to minimize the sheet feeding resistance when performing reverse sheet feeding of the recording material. With such a configuration, when the recording material is fed, the recording material falls or flutters, and skew or the like is likely to occur.

[0006]

SUMMARY OF THE INVENTION In view of the drawbacks of the prior art, the present invention is to directly or indirectly direct a vertical guide path from below to a registration roller entrance end located above the guide path. In a device for reversing the recording material, even if the clearance of the guide path is set as wide as possible to reduce the paper feeding resistance, the recording material can be fed smoothly without falling down or fluttering. To provide an improved image forming apparatus. Another object of the present invention is to provide an image forming apparatus in which the occurrence of a jam and the processing thereof are extremely easy even if the jam occurs. Another object of the present invention is to provide an image forming apparatus which is simple in terms of manufacturing and has a simple structure, and which is extremely convenient for a user.

[0007]

According to the present invention, there is provided a reversing device for reversing a recording material from, for example, a paper supply cassette 2 (first paper supply unit) housed in an apparatus main body 1 and guiding the recording material to an entrance end of a registration roller 4. The starting end of the paper feeding path 50 is extended to the paper feeding opening position of, for example, an optional paper feeding unit 60 (second paper feeding unit) disposed on the bottom side of the apparatus main body 1.
The present invention is applied to an image forming apparatus configured to be able to feed recording material fed from the optional sheet feeding unit 60 toward the entrance end of the registration roller 4 while being inverted in the sheet feeding path 50. The feature is that the guide wall 47 for guiding the recording material to the registration guide path 19 extending from the entrance end of the registration roller 4 while forcibly bending the recording material is provided in the reversing sheet supply path 50. Formed on one side, a predetermined portion (first guide wall portion 47a) of the guide wall 47 with which the leading end of the recording material fed from the paper feed cassette 2 abuts is recessed to form a wide path path 50.
a, and the second guide wall portion 47b located downstream of the first guide wall portion 47a is gradually narrowed from the wide pass path 50a to the entrance end of the registration guide path 19. Formed, while the feed opening 50
The third guide wall portion 47c extending from the position d to the first guide wall portion 47a is formed so as to have a bulge so that the path of the recording material from the optional paper feed unit 60 gradually becomes narrower. It is a feature.

According to this technical means, the first guide wall portion 4 which is pulled out of the sheet cassette 2 and inverted in a U-shape.
Since the wide path path 50a is formed by forming the recess 7a, the sheet feeding resistance can be reduced and the curvature for forcibly bending can be increased. Also, the conveyance from the optional unit 60 is performed on the path 50 wider than the position of the sheet feeding opening 50d.
The path 50c leading to the path 50a is gradually narrowed, so that even if the sheet is conveyed vertically like a vertical guide path, the width of the path 50c is reduced while the play of the recording material is suppressed.
In this configuration, the recording material enters the position a. As a result, the recording material can be reversed without fluttering.

In any of the above cases, since the exit passage 50b led to the entrance end of the registration guide path 19 is formed so as to become gradually narrower, as a result, the recording material fed from the option unit 60 side In the first embodiment, it is possible to enter the registration guide path 19 in a state where both ends are regulated by the third and second guide wall portions 47c and 47b located at both ends of the first guide wall portion 47a,
On the other hand, with respect to the recording material fed from the sheet feeding cassette 2, the sheet feeding roller 17 and the second
Can enter the registration guide path 19 in a state where both ends are regulated by the guide wall portion 47b, and in any case, the paper can be fed smoothly. As a result, even if the sheet feeding interval of the reversing sheet feeding unit is set as wide as possible to reduce the sheet feeding resistance, the recording material does not fall down or flutter at the time of feeding the recording material.
Smooth paper feeding is possible while preventing the occurrence of skew and the like.

The sheet feeding roller 17 provided in the first sheet feeding section 2 is directly opposed to the first guide wall portion 47a, and the peripheral surface of the sheet feeding roller 17 has a wide path 50a. , The path 50a at that portion can be further enlarged, and the peripheral surface of the paper feed roller 17 also functions as a driving / conveying peripheral surface of the path 50a, so that the path is smoother. Paper can be fed.

In the case where the first paper feed unit is constituted by a paper feed cassette 2 that can be pulled out of the apparatus main body 1, a paper feed path 50 for reversing is provided on the front wall side 32 of the cassette 2 so as to prevent jamming. Paper cassette 2
Pulling out the guide wall 47 of the inner wall of the cassette front wall 32
Is easily opened, and the jam processing is extremely facilitated. In the above-mentioned invention, the reversing sheet supply path 50 is not necessarily limited to only the vertical guide path, and the second sheet supply section in the second and third inventions is also limited to only the optional sheet supply unit 60. However, the present invention also includes a case where the lower-side paper cassettes are stacked.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. Not just.

FIG. 3 shows a schematic internal configuration of a page printer according to an embodiment of the present invention. The paper cassette storage space 1A, board mounting space 1B,
It is divided into three process unit mounting spaces 1C, and a paper feed opening 50
d2A, and is connected to the paper feed opening 50d2A in FIG.
An optional paper feed unit 60 (see FIG. 1) as shown in FIG.

The process unit mounting space 1C extends along the upper surface of a partition wall 1D which partitions the board mounting space 1B.
A registration guide path 19, an intermediate sheet feeding roller 18 in which the entrance end of the guide path 19 is recessed in a rectangular shape and is rotatably supported by the recess 19 a, a registration roller pair 4, a transfer roller 5
And a photoreceptor drum 6 and a fixing unit 7. On the other hand, around the photoreceptor drum 6, a cleaner 11, a particle charging unit 12, an LED unit 13, along a drum rotation direction (counterclockwise). And a developing unit 14. The photosensitive drum 6 from which the residual toner has been removed by the cleaner 11 is uniformly charged by the particle charging unit 12, and the exposure latent image corresponding to the image information is emitted by the LED unit 13. Writing to the developing unit 1
After the latent image is visualized by 4 to form a toner image, the latent image is transferred to the recording paper side by the transfer roller 5.

A manual switching lever 49 is provided at the exit end of the intermediate transfer roller 8, and the switching operation of the switching lever 49 causes the upper surface of the intermediate transfer roller 8 to be placed on a discharge tray 41 provided at the rear end of the apparatus. The paper is ejected. Reference numeral 16 denotes a display panel mounting portion provided on the front wall side of the apparatus.

As shown in FIG. 1, a recording paper trailing end detection sensor 46 having an actuator 46a that swings by passing the recording paper is provided in the registration guide path 19 on the entrance side of the registration roller 4. The feeding distance L from the trailing edge detection sensor 46 to the transfer position of the transfer roller 5 beyond the registration roller 4 is set to the charging roller (magnet) of the particle charging unit 12 along the rotation direction (arrow direction) of the photosensitive drum 6. The distance (charging distance P) from the charging position of the charging sleeve in which the assembly is inserted to the transfer roller 5 is set to be larger.

With the above configuration, the distance (exposure distance R) from the exposure position downstream of the charging position in the drum rotation direction to the transfer position (exposure distance R) is naturally smaller than the feeding distance L.

According to this embodiment, a recording sheet selectively fed from the manual sheet feeding unit 34, the sheet feeding cassette 2, or the sheet feeding unit 60 shown in FIG. After the paper passes through the intermediate paper feed roller 18 and the registration guide path 19 and waits at the entrance end of the registration roller 4, the photosensitive drum 6 is charged by the particle charging unit 12.
After the entire surface is charged, exposure is performed by the LED unit 13, development is further performed by the development unit 14, and the registration roller 4 is rotated in synchronization with the start end of the toner image carried on the photosensitive drum 6. 5, the toner image is transferred, and the image is fixed by passing the fixing roller pair 7a of the fixing unit 7 therethrough. Thereafter, the image forming apparatus is transferred via the intermediate discharge roller 8, the discharge guide 40, and the discharge roller pair 9. The paper is discharged to the paper discharge tray unit 10 on the upper surface side.

When the trailing edge of the recording paper passes through the entrance side of the registration roller 4 during the image forming operation, the trailing edge detection sensor 46 detects this by swinging of the actuator, and
The detection signal is transmitted to a control circuit (not shown) provided on the substrate 3. On the control circuit side, based on the detection signal, the charging bias of the particle charging unit 12 and the LED unit 13
Image writing and the developing bias of the developing unit 14 are sequentially stopped, and the end of the toner image carried on the photosensitive drum 6 is controlled so as not to exceed the rear end of the recording paper. Of course, in this case, when the photosensitive layer of the photosensitive drum 6 is formed of amorphous silicon, the feeding distance L> the exposure distance R is set without much consideration of the drum fatigue.
Only the image writing of the LED unit 13 may be stopped while the charging of the particle charging unit 12 is continued based on the detection signal.

On the other hand, the board mounting space 1B allows the board 3 to be set on legs 3A provided on the partition wall 1E located on the lower surface side, and the board 3 is moved along a guide 3B provided on the side wall. It can be pulled out from the right rear wall.

The cassette accommodating space 1A has a device length corresponding to the A4 size of the present apparatus, while the paper cassette 2 is a universal cassette capable of supporting the B4 or letter size. When the rear wall of the apparatus main body 1 is opened together with the front wall into which the paper feed cassette 2 is inserted and removed, and a B4 or letter size is stored, a part of the rear end regulating member from the rear end of the cassette 2 is formed. A vertical regulating plate 21 for regulating the trailing edge of the recording paper is configured to be extendable.

A paper feed roller 17 is provided at the upper front end of the cassette storage space 1A, and the recording paper stored in the recording paper storage portion of the cassette via the mounting plate 26 urged upward by a coil spring 27. Are configured to be able to contact the peripheral surface of the paper feed roller 17.

Next, the overall configuration of the paper feed cassette 2 will be described with reference to FIG. In FIG. 4, reference numeral 20 denotes a cassette base functioning as a recording paper storage section, which is formed in a flat shape without a vertical wall at the rear end side, and is position-restricted by a position restriction portion 22 provided at the rear end on the base 20 side. Trailing end regulating member 2 which advances and retreats along the longitudinal direction of the cassette while being moved
1 is attached, and the rear end regulating portion 211 that moves by the forward / backward operation of the rear end regulating member 21 is positioned on the rear end of the base 20 to regulate the position of the A4 size. By extending outward from the end further, the rear end regulation of B4 or letter size is performed. On the other hand, by moving the rear end regulation portion 211 to the inside of the base 20, B5 or postcard size smaller than A4 is set. The rear end of the length can be regulated.

Reference numeral 23 denotes a pair of width regulating plates, which are symmetrically moved in the width direction by a gear 24 pivotally supported at the center in the short direction of the base 20 and a rack meshing with the gear 24. The width of the recording paper of the size can be regulated. On the base 20 on the front side of the rack 25 of the width regulating plate 23, a flat and flat convex mounting plate 26 is pivotally supported so as to swing upward about a fulcrum 26 a provided near the rack 25.

Coil springs 27 are interposed on the left and right sides of the base between the mounting plate 26 and the base 20 in the lateral direction of the base to urge the mounting plate 26 upward. The mounting plate 26 extends to the position of the base side wall 20A on both the left and right sides, and a triangular projection 43 facing the rib 42 stands upright at the extending position. In addition, a rectangular claw portion 29 extends toward the front side at the front corner of the mounting plate 26, and engages with the claw portion 29 on the front end side of the base, thereby mounting the mounting plate. An engaging claw 36 is provided to be laid down along the base 20 against the urging force.

The engaging pawl 36 is connected to the base side wall 20.
A lock lever 30 provided on the outer wall surface side is configured so as to be swingable integrally therewith, while a lock pin 40 engaging with a lock lever 30 described later is provided on a main body side wall below the paper feed roller 17.
Project inward.

By pulling out the sheet cassette 2, the triangular projection 43 of the sheet cassette 26 is
When the mounting plate 26 is pressed downward against the elastic force of the coil spring 27 when crossing the second side, the engaging claws 36 of the lock lever 30 shown in FIG.
Are engaged. Therefore, the mounting plate 26 is laid down on the base 20 side against the elastic force of the coil spring 27 by the engagement, so that the recording paper can be easily loaded. When this is done, the tip of the cassette lock lever 30 is pressed by the body side pin 40 and engages with the pin 40 while swinging downward against the spring 51 biased against the lock lever 30, and Swinging downwards causes the engagement claw portion 36 to retreat from the engagement position, and disengagement from the engagement claw 36,
Similarly to the above, the recording paper placed on the loading plate 26 is brought into contact with the peripheral surface of the paper feed roller 17, and the lock lever 30 urged upward by the spring 51 is engaged with the main body side pin 40. In this case, the positioning is locked, and the friction pressure of the friction plate 34 is always constant. Since such a point is not the gist of the present invention, detailed description will be omitted.

Reference numeral 32 denotes a front wall which functions as a cassette drawer. The front wall 32 stands up to the lower surface position of the display panel mounting portion 16, and a manual paper feed mechanism 34 is fitted into a slit opening 32A on the upper surface. Manual feed mechanism 34
Is composed of a manual paper feed tray 341 to which a pair of width regulating plates 342 moving in the width direction is attached. The paper feed tray 341 is pulled upward from the slit opening 32A, and is tilted down by a predetermined angle toward the front side. Functions as a manual feed surface. On the other hand, the inner wall side of the cassette front wall 32 stands up to a position facing the entrance end of the registration guide path 19, and the recording material fed by the paper feed roller 17 is placed at the entrance end of the registration guide path 19. A plurality of rib-shaped guide walls 47 for guiding are formed. In addition, a reverse paper feed path 50 is formed between the recording paper storage section and the guide rib 47.

Hereinafter, these will be described in detail. The reversing sheet feeding path 50 has a starting end on the sheet feeding opening 50 of the optional sheet feeding unit 60 disposed on the bottom side of the apparatus main body 1.
The recording material fed from the paper feed cassette 2 and the optional paper feed unit 60 extends to the position d.
9 is fed toward the inlet end side. A plurality of rib-shaped guide walls 47 are formed at appropriate intervals in the width direction on the inner wall side of the cassette front wall 32 facing the reversing sheet supply path 50, and the guide walls 47 are supplied from the sheet cassette 2. A predetermined portion (first guide wall portion 47a) with which the leading end of the recording material fed by the paper roller abuts is formed in a substantially arcuate shape to form a wide curvature path, and further, the first guide wall portion 47a is formed. The second guide wall portion 47b further reaching the registration guide path 19 is formed so as to be substantially linearly inclined so as to gradually become narrower to the entrance end of the registration guide path 19,
On the other hand, the third guide wall portion 47c extending from the position of the paper feed opening 50d to the first guide wall portion 47a is formed so as to have a bulge like a spindle.
The path 50c from 0 is formed so as to gradually become narrower. Then, the sheet feeding roller 17 is directly opposed to the first guide wall portion 47a, and the peripheral surface of the sheet feeding roller 17 is configured to form a part of a wide path path 50a. In this case, the path 50a can be made even larger, and the peripheral surface of the paper feed roller 17 can also function as a drive conveyance peripheral surface in the path.

The paper feeding unit 60 is urged upward by a spring 62 as is well known, and a loading plate 61 on which a large number of recording papers are loaded, and a paper feeding support shaft supported at an upper position on the front side of the loading plate 61. A unit main body 60A including a paper roller 63, a paper feed guide 64 for guiding the recording paper fed by the paper feed roller 63 to the paper feed opening 50d of the apparatus main body 1, and the unit main body 6
A housing 60 that accommodates 0A so that it can be pulled out in the direction of the arrow.
B.

A pair of actuators 55 and 56 are provided on the side of the housing 60B, which is located above the mounting plate 61 of the paper feed roller unit 60 and is out of the recording material mounting area.
Detection piece 55 on the free end side of the actuators 55 and 56
One paper absence detection sensor 57 is disposed at the gathering position of b and 56b. The paper absence detection sensor 57 is formed in a U-shaped cross section having a concave portion 57a into which each of the actuators 56 can enter, and a light receiving element 571 and a light emitting element 572 are provided on both opposing side surfaces. 55b, 56
When b enters the concave portion 57a, the sensor signal is turned off and it is determined that there is no paper.

One actuator 56 has a swinging piece 56a located on the upper side extended from a window 58 provided at the bottom of the apparatus main body 1 so as to contact the bottom surface of the mounting plate 26,
When the recording paper placed on the mounting plate 26 rises to an empty position, the lower-side detection piece 56b is moved to the position where the recording paper placed on the mounting plate 26 becomes empty.
Is supported on the support shaft 56c so as to block the light receiving surface of the support shaft 56c. The other actuator 55 extends the swinging piece 55a located on the lower side so as to come into contact with the upper surface position of the paper supply unit 60 side mounting plate 61 separated from the recording paper storage portion, and raises the mounting plate 61. When the recording paper placed on the loading plate 61 rises to a position where the recording paper is empty, the upper detection piece 55b is pivoted so as to block the light receiving surface of the paper absence detection sensor 57 when the recording paper is raised. 55c.

As a result, as shown in FIG. 2A, detecting pieces 55b and 56 of actuators 55 and 56 for detecting the swing of the paper feed unit 60 or the paper feed cassette 2.
When b enters, light reception to the light receiving element 571 side is blocked, and it can be determined that there is no paper. Also, as shown in FIG. 2B, instead of the light emitting element and the light receiving element, proximity switches SW1 and SW2 are arranged on a U-shaped wall.
Since the a and 56a sides are made of a metal plate, the entry of the corresponding actuator 56 can be detected by each of the U-shaped walls, and the paper of any paper feeding unit (the paper feeding unit 60 or the paper feeding cassette 2) can be detected. No proximity switch SW1,
It is possible to detect with high accuracy by the sensor output from SW2.

Next, the paper feed operation from the paper feed cassette 2 and the paper feed unit 60 will be described. First, after a paper presence signal is output from the paper absence sensor 57, when the paper feed roller 17 rotates to feed paper from the paper feed cassette 2,
After the leading end of the recording paper comes into contact with the first guide wall portion 47a as the paper feed roller 17 rotates, the guide wall 47
a is forcibly bent upward along the arcuate surface of a, but at this time, the path 50a of the curved portion is formed wide,
In addition, the peripheral surface of the paper feed roller 17 also functions as a peripheral surface of the drive path in the path 50a, so that the paper feed resistance is small and the paper can be fed smoothly. After that, the recording paper is guided to the entrance end of the registration guide path 19. At this time, the exit path 50b of the path path 50 is formed so as to be gradually narrowed by the second guide wall portion 47c. As a result, it is possible to accurately enter the registration guide path 19 in a state where both ends are regulated by the paper feed roller 17 and the second guide wall portion 47b with the first guide wall portion 47a interposed therebetween. The conveyance from the optional unit 60 also passes through the paper feed guide 64 by the rotation of the paper feed roller 17 of the unit 60, and moves vertically from the position of the paper feed opening 50 d to the reverse path 5.
0, and then enter the wide pass path 50a along the bulged guide wall portion 47c with the play of the recording paper suppressed, and the recording material is removed from the guide wall 47.
Is guided to the entrance end of the registration guide path 19 while being forcibly inverted in the wide path path 50a while holding at the narrow portion of the first guide wall portion 47a. Third and second guide wall portions 47b to be
Registration guide path 1 with both ends regulated by 47c
9 can be entered.

[0035]

As described above, according to the present invention, a recording material is directly or indirectly reversed and fed from below to a registration roller entrance end located above the guide path by, for example, a vertical guide path. In the apparatus, even if the air gap of the guide path is set as wide as possible to reduce the sheet feeding resistance, it is possible to smoothly feed the recording material without causing the recording material to fall or flutter. Further, according to the present invention, the occurrence of a jam on the reverse sheet feeding path is suppressed, and even if the jam occurs, the processing is extremely easy. Further, according to the present invention, it is possible to obtain an image forming apparatus in which the structure is simplified from the viewpoint of manufacturing and the user's usability is extremely favorable. And so on.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of a main part on a front wall side of an image forming apparatus equipped with a sheet feeding unit according to an embodiment of the present invention.

FIG. 2 is an operation diagram for detecting the presence or absence of a sheet of recording material in a sheet feeding unit and a sheet feeding cassette;

FIG. 3 shows an overall configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 4 is an overall plan view of a sheet feeding cassette.

FIG. 5 is an enlarged plan view of a main part of FIG. 4, particularly showing a shape of a front side of the cassette;

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 apparatus main body 2 paper feed cassette 4 registration roller 5 transfer roller 6 photosensitive drum 12 charging unit 17 paper feed roller 19 registration guide path 20 recording material storage section 32 cassette front wall 34 manual feed section 46 rear end detection sensor 47 guide wall 47a First guide wall portion 47b Second guide wall portion 47c Third guide wall portion 50 Paper feed path 50a Wide path 50d Paper feed openings 55, 56 Actuator 57 No paper detection sensor 60 Paper feed unit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Jusuke Shimamura F-term (reference) 3F101 FA01 FB02 FC07 FC12 FC14 FC16 LA01 LB01 3F102 AA11 AB01 BB17 3F343 FA02 FB01 FC04 FC08 GA03 GB01 GC01 GD01 HC04 HC30

Claims (3)

[Claims] A second paper supply unit is disposed below a first paper supply unit housed in an apparatus main body, and a recording material is turned over from the first paper supply unit while a recording material is turned over. The leading end of the reversing sheet feeding path leading to the opening extends to the sheet feeding opening position of the second sheet feeding section, and any of the recording materials selectively fed from the sheet feeding section is fed to the sheet feeding section. An image forming apparatus configured to be capable of feeding toward a registration roller entrance end while being inverted on a path, wherein the recording material is guided to a registration guide path extending from the registration roller entrance while forcibly bending the recording material. A guide wall is formed on one side of the reversing sheet feeding path, and a predetermined portion of the guide wall (hereinafter referred to as a first guide wall portion) with which the leading end of the recording material fed from the first sheet feeding section abuts. That)
Is formed to form a wide pass path gap, and the second guide wall portion located downstream of the first guide wall portion is gradually formed from the wide pass path to the entrance end of the registration guide path. On the other hand, the third guide wall portion from the paper feed opening position to the first guide wall portion is gradually narrowed by the recording material path from the second paper feed portion. An image forming apparatus characterized by being formed with a bulge so as to have a width. 2. A paper feed roller provided in the first paper feed unit is directly opposed to the guide wall, and a peripheral surface of the paper feed roller forms a part of a wide path. Item 2. The image forming apparatus according to Item 1. 3. The paper feed unit according to claim 1, wherein the first paper feed unit is formed of a paper feed cassette that can be pulled out of the apparatus main body, and the reverse paper feed path is provided on a front wall side of the paper feed cassette. The image forming apparatus according to claim 1.