JP2000289910A - Image forming device with paper delivery switching mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To switch the delivering direction of a paper sheet with a simple structure and facilitate the jam treatment work by bending a sheet discharge passage to reverse the paper sheet when a shooter is in a reverse position where the paper sheet touches it, and delivering the paper sheet without reversion when the shooter is in a non-reverse position where the paper sheet never touches it. SOLUTION: When a shooter 61 formed in a curve about a shaft part 61a is pressed counterclockwise against the urging force by an urging spring 64 to climb over a projection 63, and pressed down by the urging spring 64 to set a locking claw 61d in a close (reverse) position for engagingly locking with the projection 63, a paper sheet delivered from a fixing unit is reversed while it is fed along a projection 61c, and delivered to a discharge tray with the printed surface down. On the other hand, when the shooter 61 is moved up through a handle 61b against the downward urging force by the urging spring 64 to set the locking claw 61d in an open (non-reverse) position for releasing from the projection 63, the delivered paper sheet is delivered with the printed surface up without being toughed to the shooter 61.

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 having a paper discharge switching mechanism for selectively switching the paper discharge direction on which an image is formed.

[0002]

2. Description of the Related Art By switching the paper discharge path of a printer such as a laser beam printer or the like, a paper discharge path of a sheet on which an image is formed is discharged (face-up) with the print surface facing upward (straight discharge). 2. Description of the Related Art A paper discharge switching mechanism that switches between a paper) and a paper discharge path (reversed paper discharge) with the print surface facing down (face down) is known.

[0003]

However, in the conventional paper discharge switching mechanism, a complicated mechanism using a flapper or the like which is driven by an actuator such as a solenoid and switches the paper conveyance direction is used. Contribute to failure. In general, a printer needs a mechanism for clearing a paper jam in the paper transport mechanism, that is, a mechanism for opening a paper transport path for performing a so-called jam processing. Is provided separately from the paper discharge switching mechanism.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a paper discharge switching mechanism which can switch the paper discharge direction without using a complicated mechanism and can function effectively at the time of jam clearance.

[0005]

According to a first aspect of the present invention, there is provided image forming means for forming an image on a sheet.
40, 50) and its image forming means (20, 40, 5).
0) in an image forming apparatus provided with a paper discharge switching mechanism for selectively switching the paper discharge direction of the paper on which an image is formed, between a reversing position where the paper contacts and a non-reversing position where the paper does not contact. Shooter (61)
And a rotation shaft (61a) provided near the upper end of the chute (61) at the inversion position and rotatably supporting the chute (61) between the inversion position and the non-inversion position. When the shooter (61) is at the reversing position, the sheet is bent by folding its discharge path along the chute (61), and when the shooter (61) is at the non-reversing position, the sheet is reversed. It is characterized by being discharged without being.

In the present invention, the position of the chute (61) can be switched between the reversing position and the non-reversing position only by rotating the chute (61). It can be switched and there is no need to use other parts. Further, the sheet feeding path can be opened only by rotating the shooter (61) to the non-reversing position, so that the jam clearing operation can be simplified.

[0007] In the paper discharge switching mechanism according to claim 1,
When the shooter (61) is at the reverse position, the sheet may be fed in a direction from the lower end to the upper end of the shooter (61). In this case,
When a paper discharge tray (70) is provided on the upper surface side of the image forming apparatus (1), paper can be easily guided to the paper discharge tray (70).

In the paper discharge switching mechanism according to the first or second aspect, as in the third aspect, the first urging means (urging the urging means so as to rotate the shooter (61) toward the non-reversing position. 64) and locking means (63, 64) for locking the shooter (61) in the inverted position.
In this case, the shooter (61) is provided with the first urging means (6).
4) to rotate to the non-inverted position, and the locking means (6)
3, 64), the shooter (61) can be positioned at the non-reversing position and the reversing position with a simple configuration.

In the paper discharge switching mechanism according to claim 3,
According to the fourth aspect, the locking means (63, 64) maintains the engagement state of the engaging portion (63) engaged with the lower end portion of the shooter (61) at the engaging portion (63). Urging means (64) for urging the shooter (61) downwardly
And may be provided. In this case, since the engagement means (63) and the second urging means (64) constitute the locking means (63, 64), the shooter (61) can be reliably moved to the inverted position by a simple configuration. Can be fixed.

In the paper discharge switching mechanism according to claim 4,
The first urging means and the second urging means may be constituted by using a common spring (64). In this case, the number of parts constituting the first urging means and the second urging means can be reduced.

In the paper discharge switching mechanism according to any one of claims 1 to 5, the shooter (6)
1) is provided with a ridge (61c) extending in a direction along the sheet feeding direction, and the sheet may be fed while contacting the tip of the ridge (61c). In this case, the paper is prevented from sticking to the shooter (61) due to static electricity, and the paper can be fed smoothly.

In the paper discharge switching mechanism according to any one of claims 1 to 6, the shooter (6)
By rotating 1) to the reverse position, the shooter (6) is rotated.
1) may constitute a part of the cover of the image forming apparatus. In this case, since the shooter (61) is exposed on the surface of the image forming apparatus (1), the shooter (61) can be easily operated manually. Further, by rotating the shooter (61) to the non-reversing position, the image forming apparatus (1) can be opened, so that the jam clearance can be easily performed.

[0013] In the paper discharge switching mechanism according to claim 7,
The fixing unit (50) of the image forming apparatus (1) may be exposed by rotating the chute (61) to the non-reversing position. In this case, by rotating the shooter (61) to the non-reversing position, it is possible to easily perform the jam clearance of the paper jammed in the fixing unit (50). Also, there is no need to provide a complicated mechanism for jam clearance.

In the paper discharge switching mechanism according to any one of claims 1 to 8, the image forming apparatus (1) includes a substrate (91) and a substrate ( A removable cover (90a) for exposing at least a part of the shooter (91), the cover (90a) being disposed below the shooter (61), and rotating the shooter (61) to a non-inverted position. Thereby, the work space around the lid (90a) may be enlarged. In this case, the substrate (91) can be easily accessed by rotating the shooter (61) to the non-reversed position.

To facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a paper discharge switching mechanism according to the present invention is applied to a laser beam printer will be described below with reference to FIGS.

FIG. 1 is a side view of the laser beam printer, FIG. 2 is a rear view of the laser beam printer viewed from the direction of the line II-II in FIG. 1, FIG. 3 is a top view of the laser beam printer,
FIG. 4 is a sectional view taken along line IV-IV in FIG. FIG.
As shown in FIG. 4 to FIG. 4, a paper feed cassette 10 for storing stacked sheets is mounted below the laser beam printer 1. The paper feed cassette 10 is detachable, and the handle 13
Can be taken out by pulling it out in the direction of arrow P (in front of the printer 1) through The paper cassette 10 is provided with a paper pressing plate (not shown) urged upward by a pressing spring (not shown), and the uppermost layer of paper stacked on the paper pressing plate is printed by the printer 1. The sheet is separated and fed by the action of the separation pad 15 by the action of the separation pad 15.

A process cartridge 20 is arranged above the sheet cassette 10. Process cartridge 2
0 is detachable similarly to the paper feed cassette 10, and is pulled out in the direction of arrow Q when toner is replaced. The process cartridge 20 includes a photosensitive drum 21 for transferring toner in contact with the paper, a transfer roller 22 facing the photosensitive drum 21, and a corona discharge to generate the photosensitive drum 21.
Scorotron-type charger 2 that charges the surface of the battery to a positive potential
Cartridge 20A including a photoconductor cartridge 20A including a toner cartridge 8, a developer chamber 24 in which toner is accumulated, a developing roller 25 that supplies toner to the photoconductor drum 21, and a supply roller 27 that supplies toner to the developing roller 25.
Consists of The developer chamber 24 is provided with an agitator 24a for stirring the toner.

The photoreceptor cartridge 20A and the developing cartridge 20B can be disassembled from each other, but when the process cartridge 20 is removed from the main body of the printer 1, they are pulled out in an integrated state. At the front of the printer 1, there is provided a cover 33 whose lower end is rotatably attached to a rotating shaft 33a.
By opening the front of the printer 1 by rotating the printer 1 clockwise, the process cartridge 20 can be attached and detached.

As shown in FIG. 4, a pair of registration rollers 31 and 32 are rotatably mounted between the process cartridge 20 and the paper feed cassette 10, respectively.

Above the process cartridge 20, a laser generator (not shown) for emitting a laser beam, a polygon mirror (hexahedral mirror) 41 driven by rotation, a lens 42, a reflection mirror 43, a reflection mirror 44, and a lens 45 are provided. Scanner unit 4 including a reflection mirror 46
0 is attached. As shown in FIG. 1, the laser beam L oscillated by the polygon mirror 41 is irradiated on the photosensitive drum 21 via the lens 42, the reflection mirrors 43 and 44, the lens 45 and the reflection mirror 46. An electrostatic latent image is formed on the surface.

On the left side of the process cartridge 20, a fixing unit 50 for fixing toner on paper is provided. The fixing unit 50 includes a heating roller 51 for heating and melting the toner on the transferred sheet, a pressing roller 52 disposed opposite to the heating roller 51, and pressing the fed sheet toward the heating roller 51. , A pair of transport rollers 53 and 54.

In FIG. 4, a shooter 61 for reversing the direction of the sheet as required is provided to the left of the transport rollers 53 and 54 (toward the back of the printer 1). Further, in FIG. 4, the paper conveyed along the shooter 61 is sandwiched from above and below and supported on the right side of the rotation shaft 62 (the front side of the printer 1), and the paper is placed on the upper surface of the printer 1. A pair of discharge rollers 72 and 73 for discharging to the formed discharge tray 70 are attached.

As shown in FIGS. 1, 3, and 4, a cover 82 that covers a part of the paper discharge tray 70 is mounted above the paper discharge tray 70. The cover 82 protrudes above the sheet discharge tray 70 at the upper and lower portions of the tray 70 in FIG.

Next, the sheet feeding operation will be described.
When the paper feed roller 14 is rotated at a predetermined timing, the paper is discharged from the paper feed cassette 10 one by one. The sheet is inverted by the action of the guide 35, and after the position of the leading end is adjusted by the registration rollers 31 and 32, the sheet is conveyed between the photosensitive drum 21 and the transfer roller 22.

On the other hand, on the surface of the photosensitive drum 21 charged by the charger 28, a laser scanner unit 40 is provided.
The laser beam emitted from the device is irradiated to form an electrostatic latent image. The electrostatic latent image on the photosensitive drum 21 is
, The supply roller 27 and the developing roller 25
Makes the electrostatic latent image visible, and the toner image is transferred to a sheet passing between the photosensitive drum 21 and the transfer roller 22.

The sheet on which the toner image has been transferred next passes between the heating roller 51 and the pressing roller 52. At this time, heat and pressure are applied to the toner image on the sheet, so that the toner image is transferred onto the sheet. Be established.

Further, the paper passes between the transport rollers 53 and 54 and is transported by being guided by the chute 61 and the guide rib 66 facing the inside of the chute 61, and then from the discharge rollers 63 and 64 to the paper output tray 70. The paper is discharged with the print side facing down (face down). Further, when the shooter 61 is opened (indicated by a dotted line in FIG. 4), the paper is discharged to the back side of the printer 1 with the printing surface facing upward (face up) as described later. . The guide rib 66 is formed by resin molding integrated with the printer body.

Next, the shooter 61 constituting the paper discharge switching mechanism of the present invention will be described. 5 is a cross-sectional view showing the periphery of the shooter 61 (a cross-sectional view taken along line IV-IV in FIG. 2), and FIG. 6 is a view of the shooter 61 as viewed from above the printer 1 (viewed from the direction of line VI-VI in FIG. 5). Figure). FIG.
As shown in FIGS. 6 to 6, the shooter 61 is formed to be curved so as to constitute a part of the back surface of the printer 1. The shooter 61 includes a shaft 61a (FIGS. 5 and 6) supported by a bearing 62 provided on the main body of the printer 1,
A handle 61b protruding to the back side of the paper and a plurality of ridges 61c extending along the paper transport path (FIGS. 5 and 6).
And a locking claw 61d formed at the distal end portion (lower end portion in FIG. 5) of the shooter 61 and abutting on a projection 63 formed on the printer 1 main body. It is mounted so as to be pivotable as a center. The protrusion 61c prevents the sheet from sticking to the shooter 61 due to static electricity.

When the shooter 61 is in the closed position (reversed position; the position shown by the solid line in FIG. 4), the paper discharged from the fixing unit 50 is reversed while being fed along the ridge 61c, and is discharged. , 73, and is discharged with the print surface facing down (face down) toward the paper discharge tray 70. On the other hand, when the shooter 61 is in the open position (non-reversed position; the position shown by the dotted line in FIG. 4), the paper discharged from the fixing unit 50 does not come into contact with the shooter 61 and is directly printed on the back side of the printer 1. Is discharged upwards (face up).

FIGS. 7 and 8 are views showing a method of mounting the shooter 61. FIG. FIG. 7A shows a state in which the shooter 61 is in the closed position, as in FIG. As shown in FIGS. 5 and 7A, a biasing spring (torsion coil spring) 64 is wound around the shaft portion 61a, and one end of the biasing spring 64 has a locking claw 65 provided on the main body of the printer 1. , And the other end of the biasing spring 64 is pressed against a protruding piece 61 e provided on the shooter 61. Thereby, the biasing spring 6
4 pushes the shooter 61 downward, and the other end of the biasing spring 64 pushes the shooter 61 clockwise. Due to the downward urging force on the shooter 61, the locking claw 61d is locked on the protrusion 63 without retreating from the protrusion 63, thereby preventing the rotation of the shooter 61.

FIGS. 7B and 8A show the shooter 6.
1 shows an operation for opening the cover 1. As shown in FIG. 7B, when an upward force is applied to the shooter 61 via the handle 61b and the shooter 61 is moved upward against the downward urging force of the urging spring 64, the locking claw is engaged. 61d
Comes off the projection 63. Therefore, as shown in FIG. 8A, the shooter 61 jumps up toward the open position by the biasing force of the biasing spring 64 in the clockwise direction. In addition,
As shown in FIG. 5, the bearing 62 has a vertically elongated groove so as to allow the shaft 61a to move upward. Therefore, even if the shooter 61 is moved upward, the shaft 61a
Does not come off the bearing 62.

FIG. 8B shows the operation when the shooter 61 is closed. As shown in FIG. 8B, the shooter 61 resists the urging force of the urging spring 64 in the clockwise direction.
Is pushed in a counterclockwise direction, the tip of the shooter 61 slides on the slope formed on the projection 63, and the shooter 61 rotates while being pushed up. When the shooter 61 gets over the protrusion 63, the shooter 61 is pushed downward by the urging force of the urging spring 64, and the locking claw 61d is locked by the protrusion 63 (the state of FIG. 7A).

As described above, the urging spring 64 simultaneously applies the downward urging force and the rotational urging force to the chute 61, and the projection 63 locks the chute 61 in the closed position. Without using a mechanism,
The shooter 61 can be opened and closed.

In the present embodiment, the shaft 61a, which is the center of rotation of the shooter 61, is formed on the upper portion of the shooter 61. Therefore, when the shooter 61 is turned to the open position, the paper discharged is the shooter 61. The paper is discharged without any contact with the paper 61 (straight paper discharge). For this reason, the shape of the shooter 61 does not affect the discharging operation at the time of straight discharging. Therefore, the shape of the shooter 61 is
It is sufficient to consider only the paper discharge operation when paper is discharged to 0 (reverse paper discharge), and the shape of the shooter 61 can be selected relatively freely. In addition, it is easy to optimize the shape of the shooter 61 so that the discharge at the time of the reverse discharge is smooth.

In the present embodiment, as shown in FIG. 4, when the shooter 61 is in the open position, the transport rollers 53 and 54 of the fixing unit 50 are exposed on the back side of the printer 1. Therefore, the hand can be inserted into the portions of the transport rollers 53 and 54 only by opening the shooter 61, so that the jam processing (the processing of removing the paper to clear the paper jam in the printer 1) can be easily performed. This eliminates the need for a complicated mechanism for jam clearance. Further, simply by opening the shooter 61, the shooter 61 and the guide rib 66 are opened.
Is also opened, and a paper jam in the reverse path can be easily dealt with.

As shown in FIGS. 1 to 4, below the shooter 61, a board box 90 for housing a main board 91 on which various control circuits of the printer 1 are mounted is provided. Opening 61 facilitates access to main board 91. That is, the shooter 61 is opened and the lid 90a of the substrate box 90 (FIG. 1)
By removing the main board 91, the chute 61 can easily reach the main board 91 located on the inner side of the board box 90 (the front side of the printer 1) and the optional board 91a that can be added to the main board 91. When the shooter 61 is opened and paper is discharged to the back side of the printer 1 (straight paper discharge), if the paper size is small, such as a postcard size, the discharged paper is placed on the lid 90a of the board box 90. Transport rollers 53, 5
4 are set. Therefore, the upper surface of the substrate box 91 can be used effectively.

The paper discharge switching mechanism of the present invention is not limited to a laser beam printer, but can be applied to other image forming apparatuses such as various printers.

[0039]

According to the first aspect of the present invention, since it is possible to switch between the reversing position and the non-reversing position only by rotating the shooter, the paper discharging direction is switched with a simple configuration. And there is no need to use other components. In addition, when the shooter is provided at an easily operable position, the sheet conveyance path can be opened only by rotating the shooter to the non-reversing position, so that the jam clearing operation can be simplified.

The image forming apparatus according to claim 1,
In a case where the paper discharge tray is provided on the upper surface side of the image forming apparatus, the paper can be easily guided to the paper discharge tray.

In the image forming apparatus according to the first or second aspect, when configured as in the third aspect, the shooter (61) is rotated toward the non-reversed position by the first urging means (64). The shooter (61) can be moved to the non-reversing position and the reversing position with a simple configuration because the moving device is moved and locked by the locking means (63, 64).

The image forming apparatus according to claim 3,
In a case where the shooter is configured as described above, since the locking means is formed by the engagement portion and the second biasing means, the shooter can be reliably fixed to the inverted position with a simple configuration.

The image forming apparatus according to claim 4,
In the case of the fifth aspect, the number of parts constituting the first urging means and the second urging means can be reduced.

In the image forming apparatus according to any one of the first to fifth aspects, when the image forming apparatus is configured as in the sixth aspect, the sheet is prevented from sticking to the shooter due to static electricity, and the sheet is smoothly moved. Can be fed.

In the image forming apparatus according to any one of the first to sixth aspects, when configured as in the seventh aspect, since the shooter is exposed on the surface of the image forming apparatus, the shooter can be easily manually operated. Can be operated.

In the image forming apparatus according to claim 7,
According to the eighth aspect, by rotating the shooter to the non-reversing position, it is possible to easily perform the jam clearance of the paper jammed in the fixing unit. Also, there is no need to provide a complicated mechanism for jam clearance.

In the image forming apparatus according to any one of the first to eighth aspects, when configured as in the ninth aspect, the substrate can be easily accessed by rotating the shooter to the non-inverted position. can do.

[Brief description of the drawings]

FIG. 1 is a side view of an image forming apparatus (laser beam printer) of the present invention.

FIG. 2 is a rear view of the laser beam printer of FIG.

FIG. 3 is a top view of the laser beam printer of FIG.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a cross-sectional view taken along line IV-IV showing a configuration near a shooter.

FIG. 6 is a view as seen from the direction of line VI-VI in FIG. 5;

7A and 7B are diagrams illustrating a method of operating the shooter, and FIG. 7A illustrates a state of the shooter at a closed position (reversed position);
(B) is a diagram showing a state in which the shooter at the closed position (reversal position) is lifted.

8A and 8B are diagrams illustrating a method of operating the shooter, wherein FIG. 8A illustrates a state of the shooter jumped up to an open position (non-inverted position), and FIG. 8B illustrates a state in which the shooter is pushed toward a closed position (inverted position). The figure which shows the state of a shooter.

[Explanation of symbols]

1 Printer (Image Forming Apparatus) 50 Fixing Unit 61 Shooter 61a Shaft (Rotating Shaft) 61c Ridge 63 Projection (Locking Means) 64 Urging Spring (First Urging Means, Second Urging Means,
Locking means) 90 substrate box 90a lid 91 substrate

Claims (9)

[Claims] 1. An image forming apparatus comprising: an image forming unit for forming an image on a sheet; and a discharge switching mechanism for selectively switching a discharge direction of a sheet on which an image is formed by the image forming unit. A chute that is movable between a reversal position where the paper contacts and a non-reversal position where the paper does not contact, and a chute provided near the upper end of the chute at the reversal position, and moves the chute with the reversal position and the A rotating shaft rotatably supported between a non-reversing position, and when the shooter is at the reversing position, the paper is bent over its discharge path along the shooter and reversed. When the shooter is at the non-reversing position, the sheet is discharged without being reversed. 2. The image forming apparatus according to claim 1, wherein the sheet is fed in a direction from a lower end to an upper end of the chute when the chute is at the reverse position. A first urging means for urging the chute to rotate toward the non-inverted position; and a locking means for locking the chute in the inverted position. The image forming apparatus according to claim 1, wherein: 4. The engaging means engages with a lower end of the shooter, and a second urging means for urging the shooter downward so as to maintain an engaged state in the engaging part. The image forming apparatus according to claim 3, further comprising: an urging unit. 5. The image forming apparatus according to claim 4, wherein the first urging unit and the second urging unit are configured using a common spring. 6. The shooter is provided with a ridge extending in a direction along a sheet feeding direction, and the sheet is fed while being in contact with a tip of the ridge. The image forming apparatus according to claim 1. 7. The image forming apparatus according to claim 1, wherein the chute is rotated to the reverse position so that the chute forms a part of a cover of the image forming apparatus. Image forming apparatus. 8. The image forming apparatus according to claim 7, wherein the fixing unit of the image forming apparatus is exposed by rotating the shooter to the non-reversing position. 9. The image forming apparatus is provided with a substrate and a detachable lid that exposes at least a part of the substrate when the substrate is removed, wherein the lid is disposed below the shooter. 9. The image forming apparatus according to claim 1, wherein a work space around the lid is enlarged by rotating a shooter to the non-reversing position. 10.