JPH0427967A - Image forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. The present invention relates to an image forming apparatus such as an electrophotographic or electrostatic recording copier or printer, and particularly an image forming apparatus that is equipped with a plurality of developing units and that can produce multicolor images. This can be effectively implemented in an image forming apparatus that forms images.

Conventionally, for example, in a full-color electrophotographic copying machine, the second
An apparatus having the configuration shown in the figure and described below has been proposed.

In other words, in the full-color electrophotographic copying machine shown in Fig. 2,
An image carrier on which a latent image is formed, that is, in this example, a photosensitive drum 1 having an electrophotographic photosensitive layer on its surface is rotationally driven in the direction of arrow X. On the left side of the photosensitive drum l, there is a primary charger 2,
A surface electrometer 3 for measuring the potential on the surface of the photosensitive drum 1 is installed diagonally below the left side of the photosensitive drum 1, and a plurality of developing units IOIM, 10IC1101Y, 101 are installed directly below the photosensitive drum 1.
A developing device 100 that loads B and moves in the left-right direction, and a transfer device 5 and a photosensitive drum 1 are installed diagonally above and to the left of the photosensitive drum 1.
Roughly directly above the photosensitive drum 1, there is a pre-static eliminator 6 for reducing the adhesion of the toner remaining on the surface of the photosensitive drum 1 after transfer to make cleaning easier. Devices 7 are arranged respectively.

Further, an optical system 10 is disposed above the electrophotographic copying machine, and the original image on the platen 8 is transferred to the photosensitive drum by an exposure section 9 located between the pre-disposed charger 2 and the surface electrometer 3. 1
configured to project onto the screen. Although any optical system can be used as the optical system 10, in this example, the first scanning mirror 11,
A CCD that integrally includes second and third scanning mirrors 12 and 13 that move in the same direction at half the speed of the first scanning mirror 11, an imaging lens 14, and a BGR filter.
15, laser scanner unit 16, fixed mirror 17
．． Consists of 18.

Here, the laser scanner unit 16 is a device well known to those skilled in the art that deflects laser light using a rotating polygon mirror, and detailed description thereof will be omitted. Further, the document illumination source 20 is configured to move together with the first scanning mirror 11.

Therefore, after passing through the lens 14, the reflected light image of the original scanned by the first to third scanning mirrors 11, 12, 13,
The CCD 15 equipped with a BGR color separation filter separates the colors and converts them into electrical signals, and this document information signal is sent to the A/
After undergoing information processing such as D, the microprocessor unit (hereinafter referred to as rMP) controls the entire copying machine as a video signal.
It's called U.J. ) will be sent to. Based on this signal, the MPU oscillates a laser beam from the laser unit via the laser driver, and this laser beam is applied to the photosensitive drum 1.
Start the copy sequence with N, 0FFL.

Furthermore, a fixing device 20 and a paper feed device 30 are arranged on the right side of the full-color electrophotographic copying machine in FIG. are provided with transfer paper conveyance systems 25 and 35, respectively.

In the above configuration, the photosensitive drum 1 is equipped with a primary charger 2, an optical system 1O1, a developing device 10, and a primary charger 2, an optical system 1O1, and a developing device 10.
0, a transfer device 5, and a cleaning device 7.

The developing device 100 includes a movable base 1 which will be explained in more detail later.
The developing unit 101M (
Magenta developing unit) IOIC (cyan developing unit), 101Y (yellow developing unit), and 101Y (black developing unit) are provided, and the color-separated latent images of each color are visualized by the corresponding developing units.

The transfer device 5 includes a transfer drum in which a transfer material carrying sheet 5b made of a dielectric film is wound around a drum frame body made up of cylindrical rings provided at both ends and a connecting portion connecting these rings. , and a transfer material adsorption means for adsorbing and holding a transfer material P (simply referred to as "transfer paper" in this specification), which is a transfer paper or other material, on a transfer material carrying sheet. The transfer device 5 transfers the transfer paper P fed from the transfer paper cassette 31 or 32 of the paper feeder 3o via the transfer paper transport system 35 to the adsorption corona charger 40 which is a part of the transfer material adsorption means. The electroconductive roller 41, which serves as a counter electrode, attracts and holds the photosensitive drum 1 on the peripheral surface of the transfer drum, and rotates the photosensitive drum 1 to transfer the developed image of each color. A transfer charger 5C is arranged inside the transfer drum 5 in the transfer area. The transfer paper P onto which each color developed image, that is, the toner image has been sequentially transferred, is separated from the transfer drum 5b by the separation charger 8 and the separation claw 8'. Next, the transfer paper P is sent to the fixing device 20 by the transfer paper transport system 25. The toner image on the transfer paper P is fixed onto the transfer paper by the fixing device 20, and then the transfer paper is discharged onto the tray 23.

Next, the reciprocating developing device 100 will be further explained.

A developing unit 101 (
IolM, I0IC1101Y, and 101B) have the same configuration, and the only difference is the color of the developer supplied inside.

Referring to FIG. 5, the developing unit 101 has an elongated developing container 106 whose cross-sectional shape is generally rectangular, and the developing container 106 has a developing sleeve 102 that has a built-in magnet (not shown) therein. is rotatably supported.

Abutment rollers 103 are provided at both end shaft portions of the developing sleeve 102 to ensure a predetermined gap between the developing sleeve 102 and the photosensitive drum 1 . Further, a driving gear 104 of the developing sleeve 102 is fixed to one shaft end of the developing sleeve 102, and the driving force of a motor 125 (FIG. 3) is transmitted to the developing sleeve 102 by a drive train.

Further, the magnet within the developing sleeve 102 is positioned at an appropriate position within the developing sleeve 102 by a positioning plate 190 disposed on the other end shaft portion of the developing sleeve.

A developing unit 101 is installed at both ends of the developing container 106.
Support shafts 105F and 105R for mounting and positioning on a moving base 120 (FIG. 2), which will be described later, are attached to the developing sleeve 102.
are provided on the same axis parallel to the axis of the

Further, inside the developer container 106, there is a screw (only the shaft part is shown) 107.10 for stirring and transporting the developer contained therein.
8 is provided, and the screw 107 and lO8 are connected to a gear train (not shown) from the drive gear 104 of the developing sleeve 102.
Driven through. The end of one of the screws, a screw 107 in this embodiment, protrudes toward the front from the developer container 106 and passes through a conveying pipe connected to a toner replenishing device (not shown). A replenishment port for connecting to a toner replenishment device is opened in the upper part of the conveyor vibrator in the shape of a long hole. A guide foot 106b is provided at the bottom of the developer container 106.
, 106c, etc. are formed, and are configured to slidably engage with a slide guide 121 attached to a movable base 120, which will be described later.

FIG. 3 is a perspective view of the entire developing device 100 seen from diagonally above and to the left in front of the copying machine. In this figure, each developing unit 101 is omitted.

The developing device 100 has a movable base 120 on which each developing unit 101 is loaded and moved, and the base 120 has a slide guide 121 (121M) that engages and holds the guide legs 106b and 106c of each developing unit 101. % 1
21C1121Y, 121B) is a stepped screw (not shown)
It is attached so that it can slide in the six directions of the arrows.

Further, the base 120 is provided with a back support plate 122 and a front support plate 123 corresponding to each slide guide 121.

The back support plate 122 is the rotation support shaft 105 of the developing unit 101.
The front support plate 123 has a hole 122' that fits with the rotation support shaft 105F of the developing unit 101.
'have. The front support plate 123 supports the developing unit 10
1 along the slide guide 121, and rotate the pivot shaft 1.
After fitting 05R into the hole 122' of the back support plate 122,
The rotation support shaft 105F and the hole 123' of the front support plate 123 are fitted, and then screwed to the base 120.

Here, the back support plate 1 provided for each developing unit of each color.
22 and the holes 122' and 123' in the front support plate 123 are adjusted using a jig or the like during assembly so that they share the same axis parallel to the axis of the photosensitive drum 1.

In this example, the back support plate 122 is screwed to a drive board 124 that supports drive gears, clutches, etc.
24 is screwed to the base 120. Further, a support plate 126 for supporting a DC motor 125 is fixed to the base 120 with screws.

As can be understood by referring to FIG. 4, the movable base 120 is equipped with a rail 127 at the rear end of the base 120, and the rail 127 is fixed to the bottom plate 60 of the copying machine. It is slidably engaged with a rail support 128 attached to the side plate 5o. On the other hand, a roller 129 having a built-in bearing is rotatably supported at the front end of the base 120 via a support plate 130. With this configuration in which the rollers 129 can roll on the bottom plate 60, the movable base 120 can be moved with respect to the bottom plate 60 and the rear side plate 50.

The movable base 120 is driven by the driving force of a stepping motor 132 attached to the bottom plate 6o by suitable support means (not shown), and by gears 133 and 134 also provided on the same support means. This is accomplished by transmitting the signal to a rack 131 fixed to the base 120 via a gear train consisting of .135.

In the above configuration, when a copying operation is started, the movable base 120 is controlled to reciprocate in a predetermined sequence by the driving force of the stepping motor 132, and each developing unit is moved between the photosensitive drum 1 and the photosensitive drum 1 during development. At the opposing position, the rotation support shaft 105 of each developing unit is
While supported by F and 105R, it rotates in a direction approaching the photosensitive drum 1 and comes to rest at a position where a predetermined gap with the photosensitive drum 1 is maintained via the abutment rollers 103. In this state, the developing sleeve 102 rotates to perform the developing process.

However, the above-mentioned electrophotographic copying machines had the following problems.

In other words, as described above (the conventional developing device 100 performs development by reciprocating the entire device, as the developing device 100 develops magenta, cyan, yellow, and black, as shown in FIGS. 2 and 1), Then, the entire developing device moves below the transfer paper conveying system 35.

For this purpose, for example, the developing device 100 is
5, if a jam (paper jam) or the like occurs in the transfer paper conveying system 35, the developing device 100 is moved to its home position (the leftmost position in FIG. 1). The jam display is displayed on the operation panel after the machine is returned to the original state.

Further, the transfer paper conveyance system 35 is movable between an operating position in which the transfer paper P is fed toward the photosensitive drum 1, that is, to the transfer device 5, and a release position in which it is evacuated from the operating position. If a jam is displayed on the operation unit, the jam can be cleared by opening the front door of the copying machine and releasing the transfer paper conveyance system 35 downward, as shown in FIG. becomes.

However, in addition to such a jam display, it is also possible that the drive motor 132 of the movable base 120 may step out and malfunction, or that the front door may be suddenly opened by the user during copying operation. It can be considered.

In this case, since the developing device 100 is not at the home position, when the front door is opened, depending on the developing position, a part of the developing device may be located below the transfer paper transport system 35, that is, the transfer paper transport system There is a possibility that it is stopped at a position corresponding to the release position of No. 35. In this case, if the transfer paper conveyance system 35 is released downward for jam removal as shown in FIG. Become. For this reason, the surface of the developing sleeve 102 of the developing unit 101 may be scratched, or the surface of the suction roller 41 may be contaminated with toner from the developer of the developing sleeve 102.

Therefore, when such a situation occurs, if the developing sleeve is damaged, the image may become white due to the damaged area of the developing sleeve, and if the suction roller 41 is contaminated with toner, There is a concern that the back side of the transfer paper may be stained by the toner-contaminated suction roller or that the transfer paper may not be properly attracted to the photosensitive drum.

Furthermore, the guide plate 203 may be deformed due to the impact caused by the collision, and in this case, paper feeding failures may occur frequently thereafter.

SUMMARY OF THE INVENTION Therefore, in view of the problems encountered in the above-mentioned conventional apparatus, it is an object of the present invention to prevent the developing device from being located at the lower release position of the transfer paper transport system when the developing device is located below the transfer paper transport system during copying operation. To provide an image forming device that can always obtain high-quality images by preventing problems such as damage to a developing sleeve and toner contamination of a suction roller by virtually preventing the release operation. That's true.

for The above object is achieved by an image forming apparatus according to the present invention.

In summary, the present invention provides an image carrier on which a latent image is formed, and at least one image carrier disposed close to the surface of the image carrier to visualize the latent image on the image carrier. The above-mentioned developing unit, a movable base for supporting and moving the developing unit, and a transfer paper conveyor for transferring the developed image on the image carrier (transfer paper transport for feeding the transfer paper toward the image carrier). In the image forming apparatus, the transfer paper transport system is movable between an operating position in which the transfer paper is fed toward the image carrier and a release position in which the transfer paper is evacuated from the operating position. ,or,
When the movable base has moved to a position corresponding to the release position of the transfer paper conveyance system, it operates in conjunction with the movement of the movable base to prevent the release operation of the transfer paper conveyance system. The image forming apparatus is characterized in that it is provided with a regulating member that operates smoothly.

IM Next, the image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

In this embodiment, the present invention is embodied in the full-color electrophotographic copying machine previously explained with reference to FIGS. 2 to 5, and FIG. 1 shows the main parts of the present invention. A more detailed configuration of a transfer paper conveyance system 35 of an image forming apparatus according to the present invention is shown.

According to this embodiment, the transfer paper conveyance system 35 includes a lower guide plate 201 whose one end is rotatably supported around a fulcrum 200 provided in the main body of the apparatus. A lower registration roller 202 that aligns the transfer paper P and the photosensitive drum 1 and then feeds the transfer paper P to the transfer device 5 is pivotally supported at the other end of the lower guide plate 201 . Furthermore, lower guide plate 2
01, one end of the suction guide plate 203 is the fulcrum 20
A suction roller 41 is rotatably supported on the other end of the suction guide plate.

The suction guide plate 203 also has a biasing member (such as a coil spring).
(not shown) urges the suction roller 41 in the direction of the transfer device 5 so that it always comes into contact with the surface of the transfer sheet of the transfer device 5.

Furthermore, the lower guide plate 201 is supported by a support plate 205 at approximately the center thereof. To explain further, the support plate 20
5 has one end fixed to a release shaft 204 that is rotatably supported on the main body of the device, and a lower guide plate 201 at the other end.
A push-up roller 206 that comes into contact with is attached. Further, the support plate 205 is biased clockwise in FIG. 1 by a biasing member (not shown) such as a spring, and the push-up roller 206 pushes the lower guide plate 201 upward in the A direction/\\. In other words, the lower guide plate 201 is biased clockwise in FIG. 1, and is engaged with the stepped portion 201a formed approximately in the center of the lower guide plate 201 to be fixedly held. During the copying operation, the transfer paper transport system 35 is maintained in the operating position, that is, in the state shown in solid lines in FIG.

Further, a release lever (not shown) is integrally attached in front of the release shaft 204, and a user or a service person can hold this lever and release the release shaft 204 and the release shaft 20.
By rotating the support plate 205 and the push-up roller 206 fixed to the lower guide plate 4 in the direction of the arrow B, the lower guide plate 201 and the suction roller 41 are released to the position shown by the dashed line in FIG. This makes it possible to handle jams.

Further, a regulating piece 207 is fixed to a part of the release shaft 204, and the regulating piece 207 has protrusions 207a and 207b.
It is equipped with

On the other hand, an opening 60a is provided in the bottom plate 60 of the apparatus main body at a location corresponding to the regulation piece 207. Furthermore, the bottom plate 6
A regulating plate 209 is provided on the regulating plate 209, and stepped screws 210 fixed to the regulating plate 209 fit into the corresponding elongated portions of the bottom plate 60 so that the regulating plate 209 can slide in the left and right direction. The top can be slid left and right.

In this way, the regulating plate 209 can cover the opening 60a by sliding.

Furthermore, the regulation plate 209 is always urged leftward in FIG. 1 by the tension spring 211, and therefore engages with the end surface of the movable base 120 and resists the force of the bow tension spring 211 in the rightward direction in the figure. It has a structure that allows it to slide.

Next, the operation of the apparatus according to the present invention having the above configuration will be explained with reference to FIG.

When the copying operation is started, the movable base 120
The moving base 120 moves to the right in FIG.
The movable base 120 slightly before reaching the position corresponding to the release position of the transfer paper transport system 35, that is, slightly before the movable base 120 and the transfer paper transport system 35 reach the interference range. The end face of 209 comes into contact with the regulating plate 209 and begins to push the regulating plate 209 against the tension spring 211. Then, when the movable base 120 reaches the release position of the transfer paper conveyance system 35, a part of the frontage 60a of the bottom plate is closed to the regulation plate 209.
It will be blocked by

Therefore, the projection 207a of the regulation piece 207 fixed to the release shaft 204 interferes with the regulation plate 209, thereby preventing the release operation of the transfer paper conveying system 35. Therefore, in order to release the transfer paper conveyance system 35, the movable base 120
is required to be manually moved to the left, thereby enabling the subsequent release operation. Therefore, according to the present invention, the above-mentioned problems are completely solved.

Furthermore, in this embodiment, another protrusion 207 is provided on the regulation piece 207.
b is provided, so when the movable base 120 is at the home position and the transfer paper conveyance system 35 is released by clearing a jam or the like, the protrusion 207b of the regulation piece is at the position 207b' within the opening of the bottom plate. Therefore, the sliding movement of the regulating plate 209 is regulated by this protrusion 207b', and the movement of the movable base 120 in the rightward direction is thereby regulated. Therefore, it is possible to prevent damage to the suction roller 41 caused by manually moving the movable base 120 to the right by releasing the transfer paper conveying system 35 and handling a jam.

Therefore, in this respect as well, according to this embodiment, it is possible to provide a more reliable device.

In the above embodiment, the regulation plate 209 was provided as a separate member, but
It goes without saying that the regulating plate 209 can also be provided integrally with the movable base 120, and the same effect can be obtained.

According to the image forming apparatus of the present invention configured as described above, when the developing device is not at the home position due to various reasons and the transfer paper conveying system is released to clear a jam, , it is possible to avoid problems such as damage to the developing sleeve or suction roller, or toner contamination of the suction roller or transfer paper guide plate, which may occur due to collision between the transfer paper conveyance system and the developing device. It has the advantage of being able to stably obtain high-quality images.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a full-color electrophotographic copying machine showing an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a sectional view of a full color electrophotographic copying machine that may embody the present invention. FIG. 3 is a perspective view of the reciprocating developing device, and each developing unit is omitted. FIG. 4 is a front view seen from the direction B in FIG. 1. FIG. 5 is a perspective view of the developing unit. 35: Transfer paper conveyance system 41: Adsorption roller 120: Moving base 200: Lower guide plate 201: Regulation piece 209: Regulation plate 211: Spring

Claims (1)

[Claims] 1) an image carrier on which a latent image is formed; and at least one developing unit installed close to the surface of the image carrier to visualize the latent image on the carrier. , a moving base that supports and moves the developing unit; and a transfer paper conveyance system that feeds transfer paper toward the image carrier to transfer the developed image on the image carrier. In the apparatus, the transfer paper transport system is movable between an operating position in which the transfer paper is fed toward the image carrier and a release position in which the transfer paper is retracted from the operating position, and When the base is moving to a position corresponding to the release position of the transfer paper conveyance system, it operates in conjunction with the movement of the movable base;
An image forming apparatus comprising a regulating member that acts to prevent a release operation of the transfer paper conveyance system.