JP2799578B2 - Electrophotographic image forming apparatus - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, such as a laser printer, a copying machine, and a facsimile, for forming an image on paper by an electrophotographic method.

2. Description of the Related Art Conventionally, this type of image forming apparatus forms a visible image on the surface by performing charging, writing, and developing together with rotation of a photoreceptor, and then transfers the visible image to a sheet of paper. The transferred image is fixed by the fixing unit, and then the sheet after the fixing is switched by the switching unit to change the discharge direction and is conveyed by the discharge conveyance unit, and a part of the sheet is transferred to the discharge stack unit by the discharge unit. Had been discharged.

However, in the conventional image forming apparatus of this type, the fixing unit, the switching unit, the sheet discharging and conveying unit, and the discharging unit are respectively constituted by a plurality of separate members, and each of the fixing units, the switching unit, the sheet discharging and conveying unit, and the discharging unit are separately provided in the apparatus main body. Was assembled.

Therefore, there are problems that the disassembly and assembly are troublesome and that positioning of each component is difficult.

Therefore, an object of the present invention is to solve such a conventional problem in an electrophotographic image forming apparatus, to facilitate assembling and disassembling, and to increase assembling accuracy.

Means for Solving the Problems Therefore, as shown in the following embodiment, for example, the present invention fixes an image transferred onto a sheet 45 by a fixing unit 26, and then switches the fixed sheet 45 to a switching unit 27. The electrophotographic image forming apparatus transports the paper 45 with the discharge direction by switching the discharge direction, and discharges a part of the paper 45 to the discharge stack unit 33 on the image forming apparatus main body 10 using the discharge means 32. In the above, the switching means 27 and the paper discharging / conveying means 28 are unitized to form a paper discharging / distributing unit 50, and the discharging means 32 is unitized to form a discharging unit 100, and the paper discharging / distributing unit 50 is formed by a pair of opposed side plates. 58 ・ 58 and the stay connecting them
60 and 94, the bottom plate 59 and the upper plate 101 are connected to each other by a structural member 61 of the apparatus main body 10 which is composed of connecting members such as the bottom plate 59 and the upper plate 101, and the discharge unit 100 is positioned and held thereon by the structural member 61. Further, the paper discharge distribution unit 50 can be freely opened and closed between an open position for opening the inside of the apparatus main body 10 and a closed position for use.

Operation Then, each of the units 90, 50 and 100 is positioned by the structural member 61 and assembled to the apparatus main body 10. At the time of disassembly, the units 90, 50 and 100 are removed from the structural member 61 and taken out of the apparatus main body 10. At the time of maintenance or the like, the paper discharge distribution unit 50 is set to the open position as necessary.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 shows a schematic configuration of a laser printer according to an embodiment of the present invention. In the figure, reference numeral 10 denotes an apparatus main body,
It is placed on an optional dedicated table 11. A drum-shaped photoconductor 12 that rotates clockwise in the figure is provided in the center of the apparatus main body 10. Around the photoreceptor 12, the charging means 13 and the optical writing means are arranged in the rotation direction in this order.
14, developing means 15, transfer means 16, and cleaning means 17 are arranged. The developing means 15 and the cleaning means 17 are housed in an image forming case 18.

On the other hand, a first sheet cassette 19 and a second sheet cassette 20 are removably mounted vertically on the right side of the apparatus main body 10 in the drawing. Further, the paper feed cassettes 19 and 20 are provided with a paper feed means 24 having paper feed rollers 21 and 21, a registration sensor 22, a pair of registration rollers 23 and 23, and the like at their mounting portions. On the other hand, on the side opposite to the paper feeding means 24 with the above-mentioned transfer means 16 interposed therebetween, a conveying means 25, a fixing means 26, a switching means 27, a paper discharging conveying means 28 and the like are arranged in order.

The paper discharge conveyance means 28 includes a face-down paper discharge path 29, a face-up paper discharge path 30, and a two-sided print paper discharge path 31.
The face-down paper discharge path 29 is also connected to a paper discharge stack 33 on the apparatus main body 10 via discharge means 32 provided on the apparatus main body 10.
Lead to. The face-up paper discharge path 30 communicates with a face-up tray 34 provided on the side surface of the apparatus main body 10 so as to be openable and closable. The two-sided print discharge path 31 leads to the dedicated table 11.

In addition, in the apparatus main body 10, for example, a main motor 35 is disposed below the transfer means 16 and
-The power supply unit 36 is arranged below the fixing means 26. On the other hand, a control means 37 is arranged in the upper part in the apparatus main body 10. The control means 37 controls the engine itself of the apparatus main body 10 and also controls the exchange with the host machine.

By the way, the dedicated table 11 is provided with a sheet reversing means 38 in communication with the above-described two-sided print discharge path 31,
From the paper reversing means 38, the paper feeding means of the apparatus main body 10 described above
A refeeding means 39 for communicating with 24 is provided. On the right side of the dedicated table 11 in the figure, a large-volume paper cassette 40 is removably loaded. The mounting portion of the large-volume paper feed cassette 40 is provided with a large-volume paper feed means 42 having a paper feed roller 41 and the like.

When the laser printer is operated, the paper feed roller 21 or the paper feed roller 41 is appropriately selected and driven, and the paper 45 is sequentially fed out of the cassettes 19 and 40. Then, the registration sensor 22 detects the leading end of the sheet 45, stops against the registration roller 23, and prevents skew here.

On the other hand, the photoreceptor 12 sequentially charges its surface with the charging means 13 while rotating clockwise in the drawing, and irradiates the laser light with the next light writing means 14 to form an electrostatic latent image on the surface, Subsequently, when passing through the developing means 15, the electrostatic latent images are sequentially visualized. Then, the registration rollers 23 and 23 are driven by aligning the image and the registration, and the registration rollers 23 and 23 are driven.
The above-described sheet 45 hitting the sheet 23 is sent out toward the photoconductor 12. Then, the image on the photoconductor 12 is transferred to the transfer unit 16.
Is transferred to the sheet 45. After the transfer, the surface of the photoconductor 12 is cleaned by the cleaning unit 17.

On the other hand, the paper 45 is sent to the fixing unit 26 by the conveying unit 25, and the image transferred thereto is fixed by the fixing unit 26.
When a large number of sheets 45 are to be discharged, or when stacking is to be performed in page order, the sheet 45 is conveyed by conveying rollers 46 through the face-down sheet discharging path 29 of the sheet discharging and conveying means 28, and the sheet is discharged via the discharging means 32. Send it out to the stack unit 33. Also,
If the paper 45 is thick paper such as a postcard, the switching means 27
The discharge direction is switched by the discharge rollers 47 and 47 through the face-up discharge path 30 of the discharge conveyance means 28, and the sheets are stacked on the opened face-up tray 34 in a face-up state. Further, when it is desired to record on the back side, the discharge direction is also switched by the switching means 27, and the transport rollers 48 are passed through the double-sided print discharge path 31 of the discharge and transport means 28.
The sheet is conveyed at 48 and guided to the sheet reversing means 38 of the dedicated table 11. Then, the sheet is reversed and conveyed again to the sheet feeding unit 24 of the apparatus main body 10 through the sheet re-feeding unit 39, and again stops against the registration roller 23. Then, the image is similarly recorded on the back surface and discharged onto the discharge stack unit 33 or the face-up tray.

In the laser printer described above, the switching means 27 and a part of the paper discharging and conveying means 28 are combined into a unit to form a paper discharging distribution unit 50 as shown in FIG. As can be seen from the drawing, a pair of unit side plates 51, 51 arranged in parallel with each other are provided on the paper discharge distribution unit 50 so as to face each other. The unit side plates 51, 51 have a vertically long rectangular shape, have rectangular protruding portions 51a, 51a at the center on one side, and have bent portions 51b, 51b having through holes above them, bent outward. Then, between the protruding portions 51a, 51a, a pair of transport rollers 52 is provided.
・ Span 52 roller shafts. Those transport rollers 52
One of the guide plates 53 forming the face-down sheet discharge path 29 is stretched over the unit side plates 51, 51 above. Guide plate
A plurality of roller windows 53a are linearly provided on the upper edge of 53.
The pair of transport rollers 46 are opposed to each other through the roller windows 53a. The roller shafts of the pair of transport rollers 46 are both extended between the unit side plates 51. On the other hand, below the transport rollers 52, one guide plate 54 forming the double-sided print discharge path 31 is also bridged over the unit side plates 51,51. A plurality of roller windows 54a are linearly provided on the lower edge of the guide plate 54, and the roller windows 54a are provided.
Are opposed to the pair of transport rollers 48 described above. The roller shafts of the pair of transport rollers 48 are also extended between the unit side plates 51. Further, a switching means 27 is provided between the upper and lower guide plates 53 and 54 between the unit side plates 51 and 51, and the pair of discharge rollers 47 and 47 described above are provided outside the switching means 27. Meanwhile, the unit side plate
Under the outer surfaces of 51, 51, as shown in the figure, engaging pins 55, 55 are respectively set to face outward.

By the way, as shown in FIG.
A pair of side plates 58 are provided on the front side and the rear side, respectively, and face each other. A stay 60 is stretched between the side plates 58 and 58 in parallel with the bottom plate 59 to form a rigid structural member 61.
The stay 60 has a U-shaped cross section and has screw holes at both ends of the side edge.
Open 60a and 60a. Further, positioning members 62, 62 having engagement grooves 62a, 62a, respectively, are attached to corresponding positions below the inner surfaces of the pair of side plates 58, 58.

Thus, the engagement pins 55, 55 described above are provided in the engagement grooves 62a, 62a.
And the lower part of the paper discharge distribution unit 50 is attached to the positioning members 62 as shown in FIG. Thereafter, the paper distribution unit 50 is rotated clockwise in FIG.
The bent portions 51b and 51b are abutted against. And the bent part 51b ・ 5
Fixing screws 63 are inserted into the through holes of 1b from the outside, and the ends are screwed into the screw holes 60a of the stay 60. Thus, the paper discharge distribution unit 50 is securely fixed in the apparatus main body 10 in a state shown by a solid line in the figure. Reference numeral 14 in the figure denotes an optical writing means, which can be taken out in the direction indicated by the arrow in the figure. 26
Is a fixing means, and as can be seen from the figure, the transport rollers 52 of the paper discharge distribution unit 50 are located at the exit thereof. In the illustrated embodiment, the engaging pins 55 are located outside the unit side plates 51 (the left side in FIG. 5) so that the paper discharge distribution unit 50 can rotate about the engaging pins 55. The lower side outer corners 51c of the unit side plates 51 are rounded as shown in FIG.

As shown by a two-dot chain line in FIG.
The paper distribution unit 50 can be held in an inclined state as shown by a two-dot chain line in FIG.
Then, by opening the paper discharge distribution unit 50 and setting it in such a state, it is possible to take out the optical writing means 14 at the back without completely removing it. Note that the arm members 65 are each formed of a pair of links that are pin-connected in the middle. When the paper discharge distribution unit 50 is in the solid line state in FIG. 5, the pair of links are folded in a V-shape by being bent at the pin connecting portion.

Now, in order to open the paper discharge distribution unit 50 so that the optical writing means 14 at the back can be taken out, or to take out the jammed paper, the laser printer shown in FIG. , On the side cover 66 of the device body 10,
An opening 67 and a door 68 for opening and closing the opening 67 are provided.

The opening 67 has such a size that the transport roller 46 of the face-down discharge path 29 and the transport roller 48 of the double-sided print discharge path 31 can be seen.

On the other hand, the door 68 allows the sheet 45 fed from the discharge roller 47 shown in FIG.
A paper outlet 69 for discharging the paper to the upper side is provided. Also, door 68
As shown in FIG. 8, the other guide plate 70 of the face-down discharge path 29 and the other guide plate 71 of the double-sided print discharge path 31 are integrally provided on the back surface thereof. The door 68 and the two guide plates 70 and 71 are integrally formed of, for example, a synthetic resin. The upper and lower ends of the door 68 are attached to the side cover 66 by hinges 72, 72, respectively, and are rotatable around the vertical pins 73, 73 of the hinges 72, 72 as shown in FIG. . A lock mechanism 74 shown in FIG. 9 that locks when the door 68 is closed is provided at the other end of the door 68.
Is provided. As can be seen from FIGS. 6 and 9, the lock mechanism 74 is provided with studs 75 and 75 protruding from the upper and lower positions of the side cover 66, and is provided on the back surface of the door 68 so as to be movable up and down. A latch lever 76 having engaging portions 76a, 76a with which a lever 75 engages, and a leading end connected to the latch lever 76 through a vertically long hole 68a formed in the door 68 and the door 6
8 and a lock lever 77 pulled out on the surface. Then, with the door 68 closed, the lock lever
If the latch lever 76 is moved downward by operating 77, the engaging portion 76a
76a can be engaged with the studs 75 to lock the door 68. Further, when the latch lever 76 is moved upward by the lock lever 77, the engaging portions 76a are disengaged from the studs 75 to release the lock.

Further, as shown in FIG. 9, a stud 78a is provided on the back surface of the door 68, and when the door 68 is closed, the stud 78a
The interlock switch 78 provided in the device body 10
b is activated.

On the other hand, the above-mentioned face-up tray 34 is provided on the surface of the door 68 as shown in FIGS. Then, both sides of the base end of the face-up tray 34 are attached to the door 68 by hinges 79 and 79, respectively.
-It is rotatable around 79 horizontal pins 80, 80. When the face-up tray 34 is turned to the use position as shown in the figure, the face-up tray 34 keeps an angle of 20 to 30 degrees with respect to the horizontal plane. As shown in FIG. 7, the face-up tray 34 has permanent magnets 81 attached to both ends of the sheet stacking surface, and suction fittings 82 attached to the surface of the door 68. Then, when the face-up tray 34 is stored in the door 68 side, the permanent magnets 81, 81 and the metal fittings 82, 82 are attracted, and the face-up tray 34 is held at that position. 10 and 11 show a state where the face-up tray 34 is stored.

As shown in FIGS. 7 and 11, a filler 83 is provided near one of the permanent magnets 81 of the face-up tray 34, and a hole 68b for passing the filler 83 is provided in the door 68. Is provided with a photo interrupter 84 for detecting the filler 83. And the face-up tray
When the photo interrupter 84 blocks the photo interrupter 84 through the hole 68b, the photo interrupter 84 detects the filler 83 and outputs a sheet discharge NO signal to the face-up tray 34. When the filler 83 is separated from the photointerrupter 84 with the face-up tray 34 as a use position, a sheet discharge OK signal to the face-up tray 34 is output.

In FIG. 7, reference numeral 85 denotes the face-up tray 34.
An auxiliary paper output tray that can be pulled out of the tray, 86 is a full detector provided in the paper output port 69 of the door 68, and a face-up tray
When the paper stack amount on 34 exceeds the specified amount, a full signal is output. In FIG. 10, reference numeral 87 denotes a handle provided at the tip of the face-up tray 34, which is used when the face-up tray 34 is rotated to a use position or a storage position.

As described above, in the illustrated laser printer, the other guide plate 70 of the face-down paper discharge path 29 and the other guide plate 71 of the double-sided print paper discharge path 31 are both provided integrally on the back surface of the door 68. Therefore, as shown in FIG. 6, when the door 68 is opened, each of the paper discharge paths 29, 30, and 31 is exposed. Thereby, the jammed paper can be easily removed. Further, since the guide plates 70 and 71 are integrated with the door 68, the number of parts is reduced, so that the structure is simplified and the cost can be reduced.

Further, in this embodiment, since the door 68 is rotatable about the vertical pins 73 of the hinges 72, 72, the sheets 45 stacked on the face-up tray 34 are not removed, and the doors 68 are kept as they are. Jam paper can be taken out.

Further, in the present embodiment, by setting the face-up tray 34 to the use position or the storage position, a discharge OK signal or a NO signal to the face-up tray 34 can be output.
Very convenient.

Next, in the illustrated laser printer, the switching unit 27 and a part of the sheet discharging and conveying unit 28 are combined into a unit, and
Further, the above-described fixing means 26 is also unitized to form a fixing unit 90 as shown in FIG. As shown in the figure,
The fixing unit 90 is provided with an elongated hole 91 and an engagement pin 92 at one end, and an engagement piece 93 having 93a at the other end. The fixing unit 90 is guided by a stay (connecting member) 94 and inserted into the structural member 61 from the front side as shown in FIG. Then, the engaging pin 95 erected on one side plate 58 of the structural member 61 is inserted into the elongated hole 91 at one end, and the engaging pin 92 is inserted into the engaging hole 58a formed in the side plate 58. Further, the engaging pin 96 erected on the other side plate 58 is inserted into the engaging hole 93a of the engaging piece 93 at the other end. This allows
The fixing unit 90 is securely positioned and fixed in the structural member 61 while preventing the warp with the stay 94. The stay 94
Is formed between a pair of side plates 58 of the structural member 61.

By the way, in the illustrated embodiment, the discharging means 32 shown in FIG. 2 is further unitized in the same manner to constitute a discharging unit 100 as shown in FIG. And as shown in the figure,
It becomes detachable at the mounting position A on the apparatus main body 10. At the mounting position A, a part of the structural member 61 shown in FIG. That is, in FIG. 12, the upper left portion (as viewed from the front of the apparatus body 10) of the upper plate (connecting member) 101 attached between the upper ends of both side plates 58 is exposed. Twelfth
As can be seen from the figure, the upper plate 101 has a bent piece 101a on the left edge.
And a paper discharge port 101b is provided slightly in parallel with it. Although omitted in FIG. 12, FIG. 13 and FIG.
As can be seen from FIG. 14, the guide members 102 and 103 are attached in parallel with the front and rear sides (similarly, front and rear when viewed from the front of the apparatus main body 10). Further, the back of the mounting position A, that is, the apparatus main body 10
Positioning pins 104 and 105 are provided in front of and near the upper center toward the mounting position A (see FIGS. 16 and 17 described later),
Further, a connector 106 is provided behind one of the positioning pins 105 (as viewed from the front) as shown in FIG.
On the other hand, as can be seen from FIGS. 13 and 15, the discharge unit 100 is provided with front and rear side plates 107 and 108, and a stay 109 is provided by connecting their lower ends. On the front and rear side plates 107 and 108,
Outwardly bent portions 107a and 108a are formed at the lower ends, respectively, and outwardly projecting pieces 107c and 108b having positioning holes 107b and 108b.
Form 108c. Further, a connector 110 is provided on the rear side of one of the projecting pieces 108c as shown in FIG. Then, as shown in FIG. 16, the bent portions 107a and 108a are fitted to the guide members 102 and 103, and the guide members 102 and 103 are fitted.
To insert the discharge unit 100 into the apparatus main body 10 in the direction indicated by the arrow a in the figure. Then, the positioning hole
The positioning pins 104 and 105 are fitted into 107b and 108b, respectively, and determine the position of the discharge unit 100 in the left, right, up, and down directions in the insertion direction. Thus, as shown in FIG. 17, the stay 109 is pressed against the bent piece 101a to hit the discharge unit 100 against the structural member 61, and the position of the discharge unit 100 before and after in the insertion direction on the apparatus main body 10 is adjusted. Determine. And screw that position
Fix with 111. At this time, the connector 106 of the discharge unit 100 is connected to the connector 106 of the apparatus main body 10 (see FIG. 14).
110 (see FIG. 13) is fitted, and the two are electrically connected to perform jam detection and fullness detection of discharged paper.

FIG. 17 shows a sheet conveying means in the discharge unit 100. The reference numeral 112 in the figure denotes a face-down paper discharge path connected to the face-down paper discharge path 29 in FIG. 2 via the paper discharge port 101b, and is conveyed while being guided by the conveyance guide plates 113. The paper 45 is sent to the lower discharge path 114 or the upper discharge path 115. Reference numeral 116 denotes a switching claw provided on the branch path, which is swung by a solenoid (not shown). In the state shown in the figure, the sheet 45 is guided to the lower paper discharge path 114, and when it swings counterclockwise from the state shown in the figure, it is guided to the upper paper discharge path 115. In the drawing, reference numerals 117 and 118 indicate transport rollers, and reference numerals 119 and 120 indicate discharge rollers.

Now, as shown in FIG. 18, a pair of transport rollers 117.1
17, both ends of one conveying roller are the front and rear side
107 and 108, and both ends of the other transport roller are supported by side guide plates 121. Although not shown, the other pair of transport rollers 118 shown in FIG. 17 also supports both ends of one transport roller with front and rear side plates 107 and 108, and supports both ends of the other transport roller with side guide plates 121. By the way, the side guide plate 121 has a U-shape in cross section, and the openable / closable cover 122 is hung on both sides thereof and is fixed with the screws 123 and 124. And
The opening / closing cover 122 is located on the left side surface of the discharge unit 100 (as viewed from the front of the apparatus body 10). As shown in FIG. 16, one end of each of the hinges 125 is attached to the outer surface of the rear side plate of the side guide plate 121 described above. Hinge
The other ends of the 125 are attached to studs 127 standing on brackets 126. The brackets 126 are fixed to the rear plate 108. And the hinge 125
, The side guide plate 121 is rotatable.
On the other hand, the inner surface of the front plate portion of the side guide plate 121 has the first
As shown in FIG. 7, the slide plate 129 is guided by upper and lower guide pins 128, 128 and is prevented from falling off by an E-ring (not shown), and is attached to the slide plate 129 so as to be able to move up and down. Then, the engaging pins 131 and 131 erected on the front side plate 107 as shown in FIG. 17 are attached to the engaging portions 129a and 129a formed on the slide plate 129, and the side guide plates 121 as shown in FIG. Penetrate and engage. The knob 132 that fits into the recess 122a of the opening / closing cover 122 described above is attached to the slide plate 129. When the knob 132 is moved upward by an external operation, the slide plate 129 moves against the tension spring 130, and the engaging portions 129a
・ Remove from 131. Therefore, when the knob 132 is pulled in this state, the side guide plate 121 rotates around the hinges 125 and 125 and can be opened together with the opening / closing cover 122 and one of the transport rollers 117 and 118.

By the way, in FIG. 13, FIG. 15, and FIG.
Reference numerals 3, 134, and 135 denote a top cover, a front cover, and a rear cover of the discharge unit 100. In FIGS. 17 and 18, reference numeral 136 denotes one of the transport rollers supported by the side guide plate 121.
This is an urging spring that presses against the other transport roller supported by 8.

The image forming apparatus according to the present invention is configured, for example, as described above. Therefore, the image transferred to the paper 45 is fixed by the fixing means.
After being fixed at 26, the sheet 45 after the fixing is switched by the switching means 27 to the discharge direction, and is conveyed by the discharge conveyance means 28.
In an electrophotographic image forming apparatus as shown in FIG. 2 in which a part of the paper is discharged to a paper discharge stacking section 33 using a discharge means 32, in the present invention, the fixing means 26, the switching means 27 and the paper discharge conveyance The unit 28 and the discharge unit 32 are unitized to form a fixing unit 90, a paper discharge distribution unit 50, and a discharge unit 100 as shown in FIG. Then, each unit 90, 50, 100 is connected to a pair of opposing side plates 5
Positioning and holding are performed by structural members 61 as shown in FIG. 12, which are constituted by the connecting members 8 and 58 and connecting members such as a stay 94 and an upper plate 101 for connecting them. That is, as shown in FIG. 1, each unit 90, 50, 100 shown by a solid line in the figure is inserted into the structural member 61 in the direction of the arrow, and is positioned and held at a position shown by a dashed line in the figure. . The specific positioning means of each unit 90, 50, 100 with respect to the structural member 61 shown in the above-described embodiment is merely an example, and it goes without saying that other positioning means may be used. Absent.

Effects of the Invention Therefore, according to the present invention, the following effects can be achieved.

The switching means and the paper discharging / conveying means are unitized to form a paper discharging / distributing unit, and the discharging means is unitized to form a discharging unit. The unit is assembled to the apparatus main body or taken out from the apparatus main body, thereby facilitating assembly and disassembly. can do.

A structural member of the apparatus main body composed of a pair of opposed side plates and a connecting member for connecting the sheet discharging and distributing unit, which is positioned and held therein, and the discharging unit is positioned and held thereon by the structural member. Therefore, both units can be positioned by a rigid structural member, and assembling accuracy can be improved.

One of the paper distribution units is openable and closable between an open position for opening the inside of the apparatus main body and a closed position for use, so that the paper distribution unit arranged so as to cover one surface of a structural member is provided. At the time of maintenance or the like, it is possible to take out internal components and units in a structural member such as an optical writing unit, for example, by simply opening it without completely removing it.

A conveyance path for discharging the sheet after the image is fixed to the discharge stack section on the apparatus main body is separated inside and outside the structural member and provided in separate discharge distribution units and discharge units. Since the paper distribution unit can be opened and closed freely, the portion to be opened and closed can be reduced.

Since both units are attached to a rigid structural member, there is no risk of loosening or misalignment over time, even when opened and closed.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view schematically showing one embodiment of the present invention shown in FIG. 2 and subsequent drawings, FIG. 2 is an overall schematic configuration diagram of an internal mechanism of a laser printer according to one embodiment of the present invention,
FIG. 3 is a perspective view of the paper discharge distribution unit, FIG. 4 is a partial perspective view of the structural member, FIG. 5 is a partial internal mechanism diagram showing a mounted state of the paper discharge distribution unit shown in FIG. FIG. 7 is a perspective view of the paper ejection side of the apparatus main body, FIG. 7 is a perspective view of a state in which the door is closed and a face-up tray is opened, FIG. 8 is a perspective view of the door viewed from the inside, and FIG. FIG. 10 is a perspective view of the state in which the face-up tray of FIG. 7 is closed, FIG. 11 is a view of the opening / closing detection mechanism of the face-up tray, and FIG. 12 is the attachment of the fixing unit to the structural member. 13, FIG. 13 is a perspective view showing the attachment of the discharge unit to the apparatus main body, FIG. 14 is a side view of the mounting position of the discharge unit viewed from the mounting side, and FIG. 15 is a view of the discharge unit viewed from the outside. Partial side view, FIG. 16 is the same perspective view,
FIG. 17 is an internal mechanism showing a paper transport system of the discharge unit,
FIG. 18 is a partial cross-sectional view of the discharge unit. 16 fixing means 27 switching means 28 discharge conveyance means 32 discharge means 33 discharge stack part 45 paper 50 discharge distribution unit 58 side plate 61 structural member 90 Fixing unit 94 Stay (connecting member) 100 Discharge unit 101 Upper plate (connecting member)

Continuation of the front page (51) Int.Cl. ⁶ identification code FI G03G 15/00 530 G03G 15/00 530 (58) Investigated field (Int.Cl. ⁶ , DB name) G03G 15/00 510-550 G03G 21 / 16-21/18 B41J 29/02 B41J 13/00

Claims (1)

(57) [Claims] An image transferred onto a sheet is fixed by a fixing unit, and the fixed sheet is conveyed by a discharge unit by switching a discharge direction by a switching unit, and a part of the sheet is discharged by a discharge unit. An electrophotographic image forming apparatus that discharges paper to a discharge stack on an image forming apparatus main body by using a switching unit and a discharge conveyance unit as a unit to form a discharge distribution unit and a discharge unit as a unit. And a discharge unit. The discharge distribution unit is a structural member of the apparatus main body including a pair of opposed side plates and a connecting member for connecting them, and is positioned and held inside the apparatus. The paper discharge and distribution unit is openable and closable between an open position for opening the inside of the apparatus main body and a closed position for use. Wherein the image forming apparatus.