JP3342186B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a recording medium.

[0002]

2. Description of the Related Art Electrophotographic image forming apparatuses such as copiers and laser beam printers used in offices and the like, particularly small desktop type apparatuses, are required to be further reduced in size and simplified in handling. .

In an electrophotographic image forming apparatus, a toner image formed on a photosensitive drum (image carrier) in an image forming section is generally transferred to a recording medium (for example, paper) conveyed from a paper feed cassette along a conveying path. ), And the transferred toner image is fixed on a recording medium upper body by a fixing device.
The recording medium is discharged onto a discharge tray.

Further, in the case of a small-sized apparatus, the image forming section is constituted by a process cartridge (for example, a photosensitive drum, a charger, a developing device, a cleaning device, and the like are integrally incorporated in a cartridge container). Is constituted by a member that performs heating and pressurization. Then, a paper feed cassette is mounted in the lower part of the box-shaped apparatus main body in the horizontal direction (substantially horizontal), and the above-described process cartridge and the fixing device are arranged in a transport path formed above the paper feed cassette. An output tray is provided. That is, the apparatus main body is reduced in size by forming a paper feed cassette at a lower portion thereof, a process cartridge and a fixing device at an intermediate portion thereof, and a paper output tray at an upper portion thereof, so as to overlap each other. The installation area (occupied area) has been reduced.

In the above-described image forming apparatus, for example, when the recording medium is jammed in the conveying path, the open / close cover of the main body of the image forming apparatus is opened, the process cartridge is first taken out, and then the conveyance is performed. A part of the conveyance path is opened by opening a path guide or the like, and then the jammed recording medium is removed.

[0006]

However, according to the above-described image forming apparatus, the recording medium before and after the image formation is supported substantially horizontally by the paper feed cassette and the paper discharge tray, respectively. There was a limit to reducing the occupied area of the main body. In other words, the substantial occupation area of the device body taking into account the occupation area of the recording medium is also
There is a problem that it is difficult to make the area smaller than the area of the largest recording medium to be used.

[0007] In addition, during the jam processing, operations such as opening the openable cover, taking out the process cartridge, and opening the transport path must be performed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus in which the area occupied by the image forming apparatus main body is reduced and the jam clearing operation is simplified.

[0009]

The invention according to claim 1 is
The electrophotographic photoreceptor and the electrophotographic photoreceptor
Detachable process having at least one process means
A cartridge, and an image of the process cartridge.
When the printer is mounted on the mounting position of the
In an image forming apparatus for forming an image by
First supporting means for supporting in the longitudinal direction, and the first supporting means
The recording medium fed from the electrophotographic photosensitive member
Transfer means for transferring the formed image, and the transfer means
Fixing means for fixing the image transferred in the step to the recording medium
And a second support for vertically supporting the recording medium after image formation.
Means, and the fixing device provided in the image forming apparatus main body.
The recording medium on which the image has been fixed by the means is discharged to the second support means.
A roller for ejecting the paper (discharge roller 38 in FIG. 1) and a front
A guide unit provided in the image forming apparatus main body so as to be openable and closable.
An opening and closing cover having a
A conveyance path of a recording medium conveyed from the fixing unit to the roller
Is constituted by the guide member, and in the open state,
The process cartridge with respect to the image forming apparatus main body.
The guide member is retracted
Opening and closing cover for opening the transfer path,
When mounting the cartridge in the image forming apparatus main body,
Guiding the process cartridge to the mounting position
A first guide portion for mounting the process cartridge.
Provided on the upstream side of the first guide portion in the mounting direction.
A second guide section for mounting the process cartridge;
When the process cartridge is removed, the process cartridge
Guide the process cartridge so that it does not touch
And a second guide portion for
You.

[0010] The invention according to claim 2 is the invention according to claim 1.
In the image forming apparatus, the second supporting means may include the opening and closing cover.
The bar is provided. Claim 3
Such an invention is directed to an image forming apparatus according to claim 1 or 2.
The guide member is provided integrally with the opening / closing cover.
Is characterized in that:

[0011]

Based on the above construction, the first support means and the second support means vertically support the recording medium to be fed (before image formation) before image formation and the recording medium after image formation, respectively. Therefore, the area occupied by the image forming apparatus main body is not directly affected by the length in the transport direction of the recording medium on which the image is to be formed. In other words, the occupied area of the image forming apparatus main body can be made smaller than the area of the recording medium by making the horizontal length of the conveying path connecting the two support means shorter than the length of the recording medium in the direction of conveyance. Becomes

Also, when the jam is cleared, the opening / closing cover is opened.
Therefore, the guide member is retracted, and the
The transport path to the rollers can be opened, and
When installing or removing the process cartridge,
Does not hit the roller, the first supporting means
Workability of the jam clearance in the transport path from
It can be significantly improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 shows a schematic configuration of a laser beam printer M using a process cartridge as an example of an image forming apparatus according to the present invention. Note that, as the recording medium P on which an image is formed, in addition to ordinary plain paper (copy paper), special paper such as thick paper and envelopes, and sheet materials other than paper, such as OHP films, may be used. Although this embodiment can be used, a case where ordinary plain paper is used will be described.

First, an outline of the configuration of a laser beam printer (hereinafter simply referred to as "printer") M shown in FIG.

The printer M is a printer main body 1 (hereinafter simply referred to as “main body 1”. In the following description,
The term “main body” refers to a frame forming the inside of the printer M in addition to a frame forming the exterior of the printer M. In particular, when referring to the frame, it is referred to as “main frame 1”. A) a first support means 1 for supporting the recording medium P before image formation in the rear portion in the vertical direction.
0, and a second support means 20 is provided at the front of the main body 1 to support the recording medium P after image formation in the vertical direction. And
The lower end 10a of the first support means 10 and the lower end 20a of the second support means 20 are connected by a transport path 30 extending from the rear part to the front part of the main body 1, and as a whole, a U-shaped path (hereinafter referred to as a path) , “Vertical U-shaped path”). The printer M further includes a process cartridge 40 integrally incorporating a drum-shaped electrophotographic photosensitive member (hereinafter, referred to as a “photosensitive drum”) 41 disposed immediately above the transport path 30, and a process cartridge 40. An information light emitting unit 50 disposed above, a transfer unit 60 disposed opposite the photosensitive drum 41 below an intermediate portion of the transport path 30, and a downstream side of the transport path 30 immediately below a lower end of the second support means 20. And a fixing unit 70 disposed at With reference to the above-described vertical U-shaped path, the process cartridge 40 and the information light emitting unit 50 are arranged inside, the transfer unit 60 is arranged outside, and the fixing unit 70 is arranged so as to straddle the transport path 30 on the downstream side. Respectively.

The operation of the printer M configured as described above will be briefly described. First, a toner image is formed on the photosensitive drum 41 by the information light emitting unit 50 or the like. On the other hand, the recording medium P is fed downward from the first
The toner image on the photosensitive drum 41 is transferred to the supplied recording medium P by the transfer unit 60 through the upstream side of the photosensitive drum 41. The recording medium P to which the toner image has been transferred is discharged upward after the toner image is fixed on the surface by the fixing unit 70, and is supported in the vertical direction by the second support unit 20.

The printer M having such a configuration and operation is as follows.
That is, in the printer M having the vertical U-shaped path, the occupied area of the main body 1 can be reduced regardless of the length of the recording medium P in the transport direction by shortening the length of the transport path 30 in the front-rear direction. It is.

The above is a schematic configuration of the printer M,
The explanation of the operation is finished, and then the first of the configurations of the respective members is described.
Details will be described in order from the support means 10.

The first support means 10 is provided at the rear of the main body 1 and has, in order from the bottom, an abutting portion 11, a front end support portion 12, and a paper feed tray 13. The abutting portion 11 supports the leading end of the recording medium P before image formation from below to support the weight of the recording medium P. The tip support portion 12 is supported by the main body 1 so as to be swingable in the front-rear direction about a shaft 12a, and is urged forward by a spring 12b disposed on the back surface of the lower end portion. The front end support portion 12 urged forward is retracted rearward by a cam member (not shown) before feeding, and only when feeding paper, the above-described cam member rotates to apply the recording medium P forward. Energize. The uppermost recording medium P among the recording media P before feeding is fed to the feeding position A by the abutting portion 11 and the separating claw.
1 and wait for feeding. When the recording medium P is fed, the next recording medium P is arranged at the feeding position A1 by the distal end support portion 12 urged by the spring 12b. The paper feed tray 13 is disposed so as to protrude vertically from the rear end of the upper surface of the main body 1. The paper feed tray 13 supports an intermediate portion and a rear end portion of the recording medium P from the back side (rear side), and vertically supports the entire recording medium P before image formation. On the front side of the paper feed tray 13, two movable regulating plates 13L, 13R for regulating the position of the recording medium P in the left and right direction (meaning left and right when viewed from the front side to the rear side), and manual feed A manual feed guide 13a for guiding the recording medium P at the time is arranged. Also, at the upper end of the paper feed tray 13, it extends upward,
An extension guide 13b that stably supports the recording medium P having a long length in the conveyance direction is disposed so as to be able to enter and exit. The paper feed tray 13 is detachably mounted on the upper surface of the main body 1. Here, the first support angle θ ₁ of the recording medium P before image formation, that is, the above-described abutting portion 11 and the front end supporting portion 1
2. The first support angle θ ₁ , which is the angle between the recording medium P and the horizontal plane, which is supported by the first support means 10 constituted by the feed tray 13 and the like, is 60 ° to 90 °.
By setting to °, it is possible to contribute to the reduction of the occupied area of the main body 1, and it is also possible to realize good feeding of the recording medium P using gravity effectively. Note that the first support angle θ ₁ is preferably set to 70 ° to 75 °.

The second support means 20 is different from the first support means 10 provided at the rear of the main body 1,
It is provided in the front of. The second support means 20 is provided on an openable and closable cover 2 (a double-dot chain line in the figure indicates the openable and closable cover 2 in the middle of the opening and closing operation) constituting a part of the main body frame 1, and is provided below. From the abutting part 21,
It has a paper discharge tray 22 and an extension tray 23. The abutting section 21 supports the rear end of the recording medium P after image formation from below, the discharge tray 22 supports the rear half of the recording medium P from the rear side, and the extension tray 23 supports the front half of the recording medium P from the rear side. . The extension tray 23 is supported by the paper discharge tray 22 so as to be able to move up and down. The recording medium P after image formation is vertically moved by the paper discharge tray 22 and the extension tray 23 pulled out above the main body 1. In a flat shape. Assuming that the angle of the recording medium P supported in the vertical direction with respect to the horizontal plane is the second support angle θ ₂ , the second support angle θ
₂ is set at 55 ° to 75 °. Note that the second support angle θ ₂ is preferably set to 65 ° to 70 °. The opening / closing operation of the opening / closing cover 2 having the paper discharge tray 22 and the like will be described later together with the attaching / detaching operation of the process cartridge 40. Further, guide ribs (guide portions) provided inside the lower portion of the opening / closing cover 2 will be described later.

The transport path 30 connects the lower end 10a of the first support means 10 and the lower end 20a of the second support means 20,
A path for conveying the recording medium P extending from the rear part to the front part of the main body 1 is configured. The transport path 30 is arranged in order from the rear (upstream) to the front (downstream).
1. Pre-transfer guides 32a, 32b, post-transfer guide 33
a, 33b, and a reversing guide 34 on the downstream side of the fixing unit 70. Also, diagonally above the separation pad 31,
A paper feed roller 35 is provided, and a transport roller 36 is provided below the paper feed roller 35. Paper feed roller 35
Is formed so that the outer peripheral surface is eccentric with respect to the shaft 35a, and the first supporting means 10
Feeds the uppermost recording medium P from the feeding roller 36 while preventing double feeding of the recording medium P with the separation pad 31.
In addition, the recording medium P is configured to be conveyed. The upstream pre-transfer guide 32a is configured to be gently lowered, and the downstream pre-transfer guide 32b is configured to be substantially horizontal.
The recording medium P is guided between the photosensitive drum 41
To the transfer position A2 formed between the transfer roller 61 and the transfer roller 61 of the transfer means 60. The post-transfer guide 33a is formed on a downwardly inclined surface, and the post-transfer guide 3
3b has a gentle concave surface. The recording medium P after the transfer of the toner image is guided to a fixing position A3 formed between the fixing film of the fixing unit 70 and a pressure roller (both will be described later) by the post-transfer guides 33a and 33b. In addition, on the most upstream side of the post-transfer guide 33a, a charge removing member 33c for removing extra charge of the recording medium P after the transfer of the toner image is mounted. The reversing guide 34 is a gently curved guide provided between the conveying roller 37 immediately downstream of the fixing unit 70 and the paper discharge roller 38 above the fixing roller 70, and moves the recording medium P after fixing the toner image upward. It guides toward the second support means 20. The reversing guide 34
Is integrally formed with the above-mentioned opening / closing cover 2.

As described above, the feeding position A1, the transfer position A2, and the fixing position A
3 are provided, and these positions A1, A2, A3
Are set so as to be sequentially arranged at lower positions in this order. Therefore, these positions A1,
The recording medium P sequentially passing through A2 and A3 is located at a high place (A1).
To the low place (A3), and smooth conveyance according to gravity is performed. Further, since the leading end of the recording medium P at this time is supported from below by the pre-transfer guides 32a and 32b and the post-transfer guides 33a and 33b, these guides 32a, 32b, 33a and 33 are used.
The sheet is conveyed in a stable posture according to b. For this reason, it is reliably introduced into the transfer position A2 and the fixing position A3, and a conveyance failure such as a paper jam is well prevented.

The process cartridge 40 includes a photosensitive drum 41, a charging roller (charging means) 42, a developing device (developing means) 43, and a cleaning device (cleaning means) 44, which are integrally incorporated into a cartridge container 45 to form a cartridge. It is detachable from the main body 1. The photosensitive drum 41 is a drum-shaped electrophotographic photosensitive member as described above, and has a motor 84 (described later) on the main body 1 side.
Is driven to rotate in the direction of the arrow R41 by a driving mechanism having a driving source of. The charging roller 42 is disposed in contact with the surface of the photosensitive drum 41, and is driven to rotate with the rotation of the photosensitive drum 41 in the direction of the arrow R41. A charging voltage in which a DC voltage and an AC voltage are superimposed is applied to the charging roller 42 by the high voltage generation unit 83 on the substrate 80 of the main body 1, and the rotation of the photosensitive drum 41 causes the surface of the photosensitive drum 41 to rotate. Charges uniformly. The developing device 43 has a toner container 43a for storing toner and a developing sleeve 43b. The developing sleeve 43b has a magnet inside, and carries toner on the surface by rotating. The toner on this surface is regulated by the regulating blade 43c and is given a charge while being charged, and is attached to an electrostatic latent image formed on the photosensitive drum 41 by the information light emitting unit 50 described later,
Form a toner image. In the process cartridge 40 according to the present embodiment, the developing device 43 can arrange the toner container 43a above and the developing sleeve 43b below, so that the toner in the toner container 43a is naturally developed by gravity. It falls toward the sleeve 43b. Therefore, there is no need to attach a special mechanism for transporting the toner in the toner container 43a toward the developing sleeve 43b, for example, a stirring member. Thus, the configuration of the process cartridge 40 can be simplified. The cleaning device 44 includes a cleaning blade 44a that rubs against the surface of the photosensitive drum 41 after the transfer of the toner image to remove residual toner on the surface, and a cleaning container 44b that collects the removed waste toner. In the upper part of the cartridge container 45, a through hole 45a for exposure is formed. The operation of attaching and detaching the process cartridge 40 to and from the main body 1 will be described later.

The information light emitting means 50 irradiates the surface of the photosensitive drum 41 with light through the above-described exposure through-hole 45a, and is entirely disposed above the process cartridge 40. The information light emitting means 50 includes a semiconductor laser 55 that oscillates a laser beam based on an image signal, and a polygon mirror 51 that reflects the laser beam while rotating it.
A motor 52 for rotating and driving the polygon mirror 51;
A lens 53 and a reflection mirror 54 are provided. The information light emitting means 50 is provided with the polygon mirror 51 as the first supporting means 1.
The reflection mirror 54 is disposed on the second support means 20 side (front side) and upward on the 0 side (rear side) and below. In other words, the entirety is arranged upward and opposite to the above-described transport path 30. By arranging in this manner, the height of the main body 1 is suppressed from being increased, and the required optical path length of the laser beam from the polygon mirror 51 to the photosensitive drum 41 via the reflection mirror 54 is suppressed with a compact configuration. In addition to this, the attachment position of the manual guide 13a of the first support means 10 can be set to a position where operability is good. The irradiation of the laser beam causes the photosensitive drum 41
An electrostatic latent image corresponding to the image signal is formed thereon.

The above-described process cartridge 40 and information light emitting means 50 are provided between the first support means 10 at the rear, the second support means 20 at the front, and the lower transport path 30, that is, a vertical U-shaped path. It is compactly located in the inner space.

The transfer means 60 includes a transfer roller 61 which comes into contact with the photosensitive drum 41 from below under the transport path 30.
And a transfer position A2 is formed between the photosensitive drum 41 and the transfer position A2. The transfer roller 61 is held at both left and right ends of a cored bar 61 a by bearings 63 urged by a spring 62, thereby abutting the surface of the photosensitive drum 41 with a predetermined pressing force. A transfer voltage having a polarity opposite to that of the toner image on the photosensitive drum 41 is applied to the transfer roller 61 by the high voltage generation unit 83 on the substrate 80, whereby
The toner image on the photosensitive drum 41 is transferred to the surface of the recording medium P passing through the transfer position A2.

The fixing means 70 includes a ceramic heater 72 held on the main body 1 via a spring 71, a fixing film 74 endlessly mounted on an outer periphery of a guide 73, and a fixing film 74 which is in contact with the fixing film 74 from below. A pressure roller 75 for forming a fixing position A3 between the film 74 and the film 74; The heat capacity of the ceramic heater 72 and the fixing film 74 is small, and therefore, the time from energization to a temperature rise to a predetermined temperature required for fixing is short. This prevents unnecessary heat from being radiated from the fixing unit 70. The fixing means 70 melts and fixes the toner image when the recording medium P, on which the toner image has been transferred on the surface at the transfer position A2 on the upstream side, passes the transfer position A3 while carrying the unfixed toner image. And is fixed on the surface of the recording medium P.

The lower part of the main body 1, that is, the above-described transport path 30
Substrate 80 is arranged below. On the substrate 80, a control unit 81, an AC input unit 82, a high-voltage generation unit 83, and a motor 84 are arranged in this order from the downstream side (front side).
These are sequentially increased in height almost in this order.
That is, as for each member on the substrate 80, a tall member is arranged at a rear portion, and a short member is arranged at a front portion. This is consistent with the above-described configuration of the transport path 30 in which the rear side is high and the front side is low. That is, the arrangement of each member on the substrate 80 is determined according to the space below the transport path 30. This contributes to downsizing of the main body 1.

Next, an image forming operation of the entire printer M having the above configuration will be briefly described with reference to FIG.

First, the recording medium P is set on the first support means 10 in the vertical direction. The photosensitive drum 41 in the process cartridge 40 is rotated and driven by the charging roller 42.
The surface of the photosensitive drum 41 is uniformly charged, for example, to a negative polarity.
The uniformly charged surface of the photosensitive drum 41 is exposed by the information light emitting means 50. The information light emitting unit 50 emits a laser beam based on the image signal, and irradiates the surface of the photosensitive drum 41. The light-irradiated portion on the photosensitive drum 41 has a negative charge removed to form an electrostatic latent image. This electrostatic latent image becomes a toner image by so-called reversal development in which a negative toner is attached by the developing device 43.
On the other hand, the recording medium P, which has been waiting with its leading end adjusted to the paper feed position A1, is supplied to the transfer position A2 by the paper feed roller 35 in such a way that the timing is adjusted to the toner image on the photosensitive drum 41. At the transfer position A2, the transfer roller 61 to which the transfer voltage of the positive polarity opposite to that of the toner is applied is applied.
The toner image on the photosensitive drum 41 is transferred onto the recording medium P. The fixing means 70 fixes the unfixed toner image on the surface of the recording medium P by receiving heat and pressure. The recording medium P on which the toner image has been fixed is discharged vertically onto the second support means 20 by the discharge roller 38 via the reversing guide 34.

The printer M according to the present embodiment holds the recording medium P before and after image formation on the first support means 10,
The area occupied by the main body 1 is reduced by being supported vertically by the second support means 20 and shortening the transport path 30.

Next, the opening and closing operation of the opening and closing cover 2 of the main body 1 and the mounting operation of the process cartridge 40 will be briefly described with reference to FIG.

While covering the front surface of the main body 1, the second
The opening / closing cover 2 also serving as the support means 20 is supported by the main body 1 so as to be swingable in the direction of the arrow R2 around the lower hinge 2a. When the cover 2 is opened as shown in the figure, a large opening 1a appears on the front surface of the main body 1. The process cartridge 40 is mounted inside the main body 1 through the opening 1a. At this time, the transport path 30 below the space to be the mounting portion of the process cartridge 40
Is configured to fall forward. On the other hand, since the information light emitting means 50 above the space is disposed upward and opposite to the transport path 30, the opening 1a is largely opened, and the mounting operation of the process cartridge 40 is extremely easy. It will be. The removal of the process cartridge 40 mounted in the main body 1 can be similarly easily performed. Further, when the process cartridge 40 is removed, the transfer path 3
The portion from 0 to the fixing position A3 from the feeding position A1 is exposed, so that the jamming of the recording medium P can be easily performed.

Next, the main body frame 1 will be described in detail.

As shown in the perspective view of FIG. 3, the main body frame 1 has a box-shaped main cover 1A, an opening / closing cover 2 for opening and closing the front surface of the main cover 1A, and a frame for supporting each device used for image formation. 1B (not shown in FIG. 3, FIG. 5
See).

As shown in a perspective view of FIG. 4, the main cover 1A is different from a cover composed of a plurality of members as in a conventional image forming apparatus, and has a single upper surface and four front, rear, left and right side surfaces. Five surfaces are integrally formed by resin molding. An opening 1a for attaching and detaching the process cartridge 40 is formed at the front of the main cover 1A. The opening 1a is openably and closably covered by an opening / closing cover 2 described later. Locking claws 1b are provided at the lower left and right ends on the inner rear surface of the main cover 1A, respectively.
Further, positioning projections 1c are provided at the lower portions of the left and right ends on the outside of the front surface, respectively. After assembling the substrate 80, the transfer unit 70, the transfer unit 60, and the like on the frame 1B, the above-described main cover 1A is put on the frame 1B from above. At this time, it is locked to the frame 1B by the locking claw 1b, and the positioning is performed by the projection 1c. In this state, the main cover 1A is fixed by screwing the main cover 1A to the frame 1B. In addition, the above-mentioned screw is attached to a portion that cannot be seen when the opening / closing cover 2 is closed.

As described above, the main cover 1A is integrally formed, and is simply covered on the frame 1B from above.
It becomes possible to attach the device exterior. Therefore,
As compared with the conventional configuration in which the cover constituting the exterior of the apparatus is divided into a plurality of members and these are individually assembled by screwing or the like, in this embodiment, the exterior is extremely easy to assemble, and the assembling time is reduced. Be shortened. Further, since the main cover 1A is positioned with respect to the frame 1B by the convex portion 1c, the mounting accuracy is also improved.

The size of the main cover 1A is reduced to the following range.
And an image recording apparatus for recording an image on a recording medium of A4 size (210 mm to 297 mm) has been miniaturized.

(1) Height 200 mm to 250 mm (2) Depth 250 mm to 300 mm (3) Width 300 mm to 350 mm Next, a configuration for mounting the process cartridge 40 to the main cover 1A and the frame 1B, and mounting of the process cartridge The operation will be described.

In this embodiment, in order to mount the process cartridge 40, the frame 1B and the main cover 1
A, the first guide portion G ₁ and the second guide portion 1
d is provided. The first guide portion G ₁ and the second guide 1d is provided near the lower portion of the left opening 1a of the main cover 1A, also the same is provided near the lower portion of the right opening 1a. The left side and the right side are arranged at mutually symmetric positions.

The above-mentioned first guide portion G ₁ is inclined downward toward the inner part of the frame 1 B, and has a slot G ₂ at the mounting position of the process cartridge 40. Also the second
Guide 1d are extending in the same inclined thereto in front of the first guide portion G _1, and a guide shaped to avoid contact with the discharge roller 38 is formed with ribs.

On the other hand, on the outer surface of the cartridge container 45 of the process cartridge 40 in the longitudinal direction (the direction along the axis of the photosensitive drum 41), the groove protrudes outward from the rotation center of the photosensitive drum 41 and is provided in the frame 1B. the first cylindrical projection 45c having substantially the same radius as the G ₂ Yes and is provided, and to position the mounting posture of the process cartridge 40 is provided protrudes in the frame 1B outward in the longitudinal direction lateral surfaces of the cleaning vessel 44b the second cylindrical projection 45d having a first guide portion G ₁ and substantially the same radius are provided with.

In the above configuration, when the process cartridge 40 is mounted on the main body 1, first, the opening / closing cover 2
Is released, the first cylindrical projection 45c is mounted on the second guide portion 1d, and then the second cylindrical projection 45d is mounted, and the process cartridge 40 is inserted in this state.

At the time of insertion, the first cylindrical projection 4
5c and the second columnar projection 45d are placed and inserted in the second guide portion 1d formed on the main cover 1A, so that there is no possibility that the process cartridge 40 may hit the second paper discharge roller 38 or the like to damage them. When configuring the main cover 1A having a different design,
Since the contact of the process cartridge 40 with other components can be avoided only by changing the shape of the second guide portion 1d of A,
Image forming apparatuses of various designs can be supplied at low cost without changing the inside of the image forming apparatus.

Next, the cover 2 will be described in detail with reference to FIG.

The opening / closing cover 2 is provided at the lower ends of the left and right ends.
A convex portion 2a serving as an opening / closing center when attached to the main cover 1A, a contact portion 21 for supporting a rear end of the discharged recording medium P in a central portion, and a post-discharge recording portion further on an upper portion. It has a paper discharge tray 22 that supports the image forming side of the medium P.
A large number of guide ribs (reversal guides) 34 extending in the vertical direction are formed on the inner side of the lower part in the left-right direction. The above-mentioned convex portion 2a, contact portion 21, paper discharge tray 22, and guide rib 34 are integrally formed as the open / close cover 2 by molding with resin.

On the other hand, as shown in FIG. 4, a through hole 1e for rotatably supporting the convex portion 2a of the opening and closing cover 2 and a guide rib 34 entering and exiting with the opening and closing operation of the opening and closing cover 2, as shown in FIG. A window 1f is formed. The width of the window 1f in the left-right direction is set to be larger than the maximum width of the recording medium P used for image formation.
From the storage medium P.

A jam in a small-sized image forming apparatus as in this embodiment often occurs over both the transfer unit 60 and the fixing unit 70. During normal image formation, the opening / closing cover 2 is closed, and the guide rib 34 is
As shown in (a), it enters through the window 1f and faces the auxiliary guide 34a to form a part of the transport path 30.

When the opening / closing cover 2 is opened as shown in FIG.
It moves with the opening / closing cover 2 and retracts from the window 1f,
The transport path 30 is opened. That is, the process cartridge 4
The operation of opening the opening 1a to remove the recording medium P and the operation of retracting the guide rib 34 from the conveyance path 30 of the recording medium P and opening the window 1f to remove the recording medium P after the fixing unit are performed by opening and closing covers. Since the operation can be performed in a single behavior of opening 2, the workability at the time of jam clearance is greatly improved. <Embodiment 2> In the above embodiment, the information light emitting means 5
As 0, instead of the one that emits a laser beam, L
It is also possible to use an ED array. Photosensitive drum 41
A large number of LEDs are arranged along the generatrix so as to face the surface of the photosensitive drum 41, and while rotating the charged photosensitive drum 41, ON / OFF of each LED is selected based on an image signal, whereby the photosensitive drum 41 is selected. An electrostatic latent image is formed thereon. According to this, the configuration can be further downsized and simplified. <Embodiment 3> The members constituting the above-described process cartridge 40 are not limited to those shown in FIG. For example, an electrophotographic photosensitive member as an image carrier and at least one of a charging unit, a developing unit, and a cleaning unit as a process unit are integrally formed as a cartridge so as to be detachable from the image forming apparatus main body. You may.

Further, an electrophotographic photosensitive member as an image carrier and a charging unit, a developing unit or a cleaning unit as a process unit are integrally made into a cartridge, and this cartridge is detachably mountable to the main body of the image forming apparatus. Alternatively, at least the developing means and the electrophotographic photosensitive member as an image carrier may be integrally formed as a cartridge so as to be detachable from the image forming apparatus main body. <Embodiment 4> The first support means 10 of the above embodiment can be constituted mainly by a paper feed cassette. A vertical cassette mounting portion is provided at a rear portion of the main body 1, and a sheet cassette in which a recording medium P is stored is mounted on the cassette mounting portion from above to support the recording medium P in a vertical direction. is there. In this case, the first support means is constituted by the cassette mounting section and the sheet feeding cassette.

[0051]

As described above, according to the present invention,
First support means for vertically supporting a recording medium to be fed before image formation, second support means for vertically supporting a recording medium after image formation, and a transport path from the former to the latter, A vertical U-shaped path is formed, and an image carrier is disposed on a transport path inside the U-shaped path, and an information light emitting unit is also disposed above the inner image carrier. On the other hand, a transfer unit is disposed below the transport path. By adopting a configuration in which the fixing unit is disposed downstream of the unit, the length of the conveyance path can be shortened, the speed of image formation can be increased, and the area occupied by the image forming apparatus main body can be reduced. .

To open the opening / closing cover when clearing jams
Therefore, the conveyance path of the recording medium from the fixing unit to the roller is opened.
Once released, jam handling is improved. Also, the first support hand
A second support unit for performing jam processing from the step to the fixing unit;
Provided in the main body of the image forming apparatus for discharging the recording medium
Can be removed without hitting the cartridge against the
The conveying path from the first support means to the fixing means is opened.
As a result, the jam handling property is improved. That is, the second support means
Roller for discharging the recording medium to the image forming apparatus main body
Side, and transported from the fixing means to the roller.
A guide member that constitutes the recording medium transport path is
In the mounting direction of the process cartridge.
A second guide portion provided upstream of the first guide portion;
When attaching or detaching the process cartridge,
Make sure that the process cartridge does not contact the roller.
The second gas for guiding the process cartridge
By providing the id part, as a synergistic effect of these,
The guide section is opened by opening the open / close cover during jam clearance.
Evacuation of the material, and the conveyance path from the fixing means to the roller
Can be opened and the process cartridge
When attaching / detaching, the process cartridge hits the roller.
There is no danger, so the first support means to the fixing means
Can greatly improve the operability of jam handling in the transport path.
Can be.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating a schematic configuration of an image forming apparatus according to a first embodiment.

FIG. 2 is an operation explanatory view showing an opening / closing operation of an exterior cover and an attaching operation of a process cartridge in the first embodiment.

FIG. 3 is a perspective view illustrating a configuration of a main body frame according to the first embodiment.

FIG. 4 is a perspective view illustrating a configuration of a main cover according to the first embodiment.

FIG. 5 is an operation explanatory view showing mounting of the process cartridge on the main body frame in the first embodiment.

FIG. 6 is a perspective view illustrating a configuration of an opening / closing cover according to the first embodiment .

FIG. 7A is a longitudinal sectional view illustrating a closed state of the opening / closing cover according to the first embodiment. (B) is a longitudinal sectional view showing an open state of the opening and closing cover of the first embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body (printer main body, main body frame) 1A Main cover 1B Frame 1a Opening 1d Second guide 1f Window 2 Openable cover 2a Convex part 10 First support means 20 Second support means 21 Contact part 22 Discharge Tray 30 Conveying path 34 Guide part (guide rib) 40 Process cartridge 41 Image carrier (photosensitive drum) 42 Charging means (charging roller) 43 Developing means (developing device) 44 Cleaning means (cleaning device) 45 Cartridge container 45c First cylindrical shape Projection 45d Second cylindrical projection 50 Information light emitting unit 51 Polygon mirror 60 Transfer unit 61 Transfer roller 70 Fixing unit 72 Ceramic heater 74 Fixing film 75 Pressure roller 80 Substrate 81 Control unit 82 AC input unit 83, 85 High voltage generation unit 84 Motor G _1st guide Part G ₂ slot M image forming apparatus (laser beam printer) P recording medium θ ₁ first support angle θ ₂ second support angle

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Kuroda 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Takeshi Kenmura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Hiroshi Goto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toshimitsu Iso 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 72) Inventor Yoshihiro Matsuo 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-6-148967 (JP, A) JP-A-3-231259 (JP, A) JP-A-4-346362 (JP, A) JP-A-63-6581 (JP, A) JP-A-4-276765 (JP, A) JP-A-4-339678 (JP, A) JP-A-4-302264 (JP JP, A) JP-A-5-113699 (JP, A) JP-A-4-275561 (JP, A) JP-A-3-272926 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15 / 00 550 G03G 21/16-21/18

Claims (3)

(57) [Claims] (1) Electrophotographic photoreceptor and the electrophotographic photoreceptor
Attachment and removal with at least one working process means
A process cartridge, comprising:
The cartridge is attached to the attachment position of the main body of the image forming apparatus.
In an image forming apparatus that forms an image on a recording medium by using
hand, First support means for supporting the recording medium in the longitudinal direction; With respect to the recording medium fed from the first support means,
Transfer for transferring an image formed on the electrophotographic photosensitive member
Means, For fixing the image transferred by the transfer means to a recording medium
Fixing means, Second support means for supporting the recording medium after image formation in the vertical direction
When, An image formed by the fixing unit provided in the image forming apparatus main body;
Is discharged to the second support means.
Rollers and A guide provided on the image forming apparatus main body so as to be openable and closable.
An opening / closing cover having a member, which is closed in a closed state.
Conveyance of the recording medium conveyed from the fixing means to the roller
The path is constituted by the guide member, and in the open state
The image forming apparatus main body of the process cartridge
And the guide member is retracted.
Opening and closing cover to open the transport path, The process cartridge is mounted on the image forming apparatus main body.
When mounting, the process cartridge is mounted in the mounting position.
A first guide portion for guiding The first direction in the mounting direction of the process cartridge
A second guide portion provided upstream of the guide portion,
When attaching or detaching the process cartridge,
To prevent the cartridge from contacting the rollers.
Second guide unit for guiding the process cartridge
And comprising An image forming apparatus comprising: (2) The second support means is provided on the cover.
Have been The image forming apparatus according to claim 1, wherein: (3) The guide member is integrated with the cover
Provided in the The image forming apparatus according to claim 1, wherein:
Place.