JPH09325605A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce, that is, prevent the scattering of toner between a developing unit and a hopper, without impairing operability for the supply of the toner, the maintenance check work of a device, etc. SOLUTION: An eccentric cam developing unit for selectively bringing four developing devices close to a photoreceptive drum is moved in the direction of an arrow B by an eccentric cam, etc., by the start of a copying operation, so that the supplying port, 31 of a toner container 30 is inserted into the opening part of a supplying port, 41 and an external wall part, 32 covering the circumference of the supplying port 31 has a such positional relation that a part covers the outside of an external wall part 42 covering the circumference of the supplying port 41. Thus, the gap between the supplying ports 31 and 41 is reduced to prevent the scattering of the toner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, and more particularly to a color image forming apparatus in which a developing device moves.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic system, an electrostatic latent image formed on the surface of a photosensitive drum as an image carrier is developed by a developing device and visualized as a toner image. ing.

Particularly in a full-color copying machine or the like, a predetermined developing device containing yellow, magenta, cyan, and black toners is selectively brought close to the photosensitive drum corresponding to each separated color, and the latent image on the photosensitive drum is detected. After developing the image, the operation of separating from the photosensitive drum is sequentially repeated.

Toner replenishment to the developing device is performed when the developing device is operating, that is, when the developing device approaches the photosensitive drum, the toner supply port for supplying toner to the hopper and the toner supply port of the developing device are combined. By doing so, it is performed as needed.

[0005]

However, in the above-mentioned prior art, when the developing device is not developing, the toner supply port of the hopper and the toner supply port of the developing device are completely separated from each other. Toner is scattered from the
The inside of the device was sometimes soiled with toner.

On the other hand, when the hopper is pulled out from the inside of the apparatus main body and taken out to the outside, for example, for supplying toner to the hopper or for maintenance and inspection work of the apparatus, it is necessary that the developing device and the hopper are sufficiently separated from each other. , Workable.

Therefore, the present invention provides an image forming apparatus capable of reducing and preventing toner scattering between a developing device and a hopper without impairing workability such as toner supply and maintenance and inspection work of the device. Has an aim.

[0008]

According to the first invention of the present application, the above-mentioned object is to provide an image carrier, a developing device having a replenishing port for receiving a developer, and a replenishing port having a replenishing port. And a developer supplying device for supplying the developer to the developing device, the developing device is movably arranged between a non-developing position and a developing position, and the developer supplying device maintains the developer supplying position and maintenance. An image forming apparatus movably disposed at a work position, comprising an outer wall portion covering a supply port of the developer supply device and an outer wall portion covering a supply port of the developing device. The developer supply device is in the developer supply position,
When the developing device is in the non-developing position, the developing device is placed at a position where a part of the outer wall portion that covers the periphery of the supply port and a part of the outer wall portion that covers the periphery of the replenishment port overlap each other. This is achieved by providing a means for moving.

According to the second invention of the present application,
The above object can be achieved by having a plurality of developing devices in the first invention.

Further, according to a third invention of the present application, in the above-mentioned first invention or the second invention, the above-mentioned object is the developer supply device and the developing device. When the developing device is in the developing position at the replenishment position, either one of the end face of the outer wall portion covering the periphery of the supply port of the developer supply device or the end face of the outer wall portion covering the periphery of the supply port of the developing device or This is achieved by having a positional relationship in which both of them come into contact with either or both of the developing device and the developer supplying device.

That is, according to the first aspect of the present invention, since the developer supply device is movable between the developer supply position and the maintenance work position, when the developer supply position is present, the developer supply device is located. The supply port and its outer wall part and the supply port of the developing device and its outer wall part are in a state of being separated from each other, but with a part of the outer wall part that covers the periphery of the supply port by means of moving the developing device. By moving the developing device to a position where a part of the outer wall portion covering the periphery of the supply port overlaps each other, leakage of the developer from the supply port and the supply port to the outside is eliminated.

Further, in the second invention according to the present application, since a plurality of the developing devices of the first invention are arranged, the plurality of developing devices are developed as in the first invention. The developer of each color is replenished while preventing the leakage of the developer, and the maintenance work is facilitated.

Further, in the third invention according to the present application, the developer supplying device and the developing device according to the first invention or the second invention are such that the developer supplying device is at the developer replenishing position. When the apparatus is in the developing position, either one or both of the end surface of the outer wall portion surrounding the supply port of the developer supply apparatus or the end surface of the outer wall portion covering the supply port of the developing apparatus is Since it has a positional relationship of contacting either or both of the developer supply devices,
Reliably prevent developer leakage when replenishing the developer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. 1 to 6 of the accompanying drawings. FIG. 6 is a schematic sectional view of the color image forming apparatus in this embodiment. The apparatus of this embodiment shown in the figure has a configuration in which a digital color image reader unit is provided in the upper portion and a digital color image printer unit is provided in the lower portion.

In the reader unit, the original 50 is placed on the original table glass 51 and exposed and scanned by the exposure lamp 52, so that the reflected light image from the original 50 is condensed on the full color sensor 54 by the lens 53, and the color is obtained. Obtain a color separated image signal. Then, the color-separated image signal is processed by a video processing unit (not shown) through an amplifier circuit (not shown) and sent to the printer section.

In the printer section, a photosensitive drum 1 which is an image bearing member is rotatably arranged in the direction of an arrow, and a pre-exposure lamp 11, a corona charger 2 and a laser exposure are provided around the photosensitive drum 1. An optical system 3, a potential sensor 12, four developing devices 4y, 4c, 4m, and 4Bk of different colors, an on-drum light amount detection unit 13, a transfer device 5, and a cleaning device 6 are arranged.

The image signal sent from the reader section is converted into an optical signal by a laser output section (not shown) of the laser exposure optical system 3, and the converted laser light is reflected by the polygon mirror 3a. , Lens 3b and mirror 3c
And is projected as a light image E on the surface of the photosensitive drum 1.

At this time, the photosensitive drum 1 is rotating in the direction of the arrow, and after the static elimination by the pre-exposure lamp 11, the charger 2
Therefore, a latent image is formed by the irradiation of the light image E for each of the above-described separated colors.

Next, this latent image is conveyed to the portion facing each developing device as the photosensitive drum 1 rotates, and the eccentric cam 2 is conveyed.
By the operations of 4y, 24c, 24m, and 24Bk, the developing devices 4y, 4c, 4m, and 4Bk alternatively approach the photosensitive drum 1 according to each separated color, develop the latent image on the photosensitive drum 1, and A toner image based on resin is formed on 1.

On the other hand, in synchronization with such a toner image forming process, the recording sheet P is conveyed from the sheet cassette 7, and the toner image on the photosensitive drum 1 is transferred onto the recording sheet P by the transfer device 5.

In this embodiment, the transfer device 5 includes a transfer roller 5a, a transfer charging device 5b, and a suction roller 5 facing the suction charging device 5c for electrostatically sucking the recording sheet P.
g, an inner charger 5d, and an outer charger 5e, and a recording sheet carrying sheet made of a dielectric material such as a polycarbonate film is provided in the peripheral opening area of the transfer drum 5a which is rotatably supported. Hereinafter, a supporting sheet) 5f is integrally stretched in a cylindrical shape.

Therefore, by rotating the transfer drum 5a, the recording sheet P carried on the carrying sheet 5f is
The toner image on the photosensitive drum 1 is conveyed to a portion facing the photosensitive drum 1, and is transferred onto the recording sheet P by the transfer charger 5b. As a result, a desired number of color images are transferred to the recording sheet P, and a full color image is formed.

Further, when the transfer of the four color toner images is completed in this way, the recording sheet P is separated from the transfer drum 5a by the action of the separation claw 8a, the separation push-up roller 8b and the separation charger 5h, and the heat roller fixing is performed. It is conveyed to the container 9.
Then, in the heat roller fixing device 9, the recording sheet P on which the full-color image has been formed is nipped and conveyed by the heat roller to heat and pressurize the toner image so that the toner image is melted and fixed on the recording sheet P.

After that, when an image is formed on only one side of the recording sheet P, the recording sheet P after fixing is discharged to the tray 10 as it is, and the image forming process is completed. After the transfer, the photosensitive drum 1 is subjected to the image forming process again after cleaning the residual toner on the surface with the cleaning device 6.

On the other hand, when images are to be formed on both sides of the sheet, immediately after the heat roller fixing device 9 is discharged, the transport path switching guide 19 is driven, and the transport vertical path 20 is first guided to the reverse path 21a. After that, the reversing roller 21b is rotated in the reverse direction so that the trailing end of the fed-in roller is the leading end and the roller is withdrawn in the direction opposite to the fed-in direction, and is stored in the intermediate tray 22.
Then, the image is formed on the other surface by the above-described image forming step.

In the apparatus of this embodiment, the fur brush 14 and the carrier sheet 5f are used to prevent the powder from being scattered on the carrier sheet 5f of the transfer drum 5a and the oil on the recording sheet P. Through the fur brush 1
The cleaning is performed by the action of the backup brush 15 facing the oil removing roller 16 and the backup brush 17 facing the oil removing roller 16 via the oil removing roller 16 and the carrying sheet 5f. Such cleaning is performed before or after image formation, and at any time when a jam (paper jam) occurs.

Further, in the present embodiment, the eccentric cam 25 is operated at a desired timing and the cam follower 5i integrated with the transfer drum 5a is operated, so that the gap between the carrier sheet 5f and the photosensitive drum 1 can be arbitrarily set. It can be set to. For example, during standby or when the power is off, the interval between the transfer drum 5a and the photosensitive drum 1 is increased.

Next, with reference to FIGS. 4 and 5, the construction of a storage container and other units for storing the four hoppers, which are the four developer supply devices in the image forming apparatus of this embodiment, will be described. 4 shows the storage container stored in the printer unit main body, and FIG. 5 shows the storage container pulled out from the printer unit main body.
It is a simplified diagram showing a state of being rotated by 80 °.

The storage containers are the developing devices 4Bk, 4m and 4m.
It is provided with four hoppers for supplying the toners of the colors to be supplied to c and 4y, and is arranged on the front side of the photosensitive drum 1 and the four developing devices 4Bk, 4m, 4c and 4y.

As shown in FIG. 5, each hopper has a toner container 30Bk, 30m, 30c, 30y for containing toner.
And any of the developing devices 4Bk corresponding to this toner,
4m, 4c, 4y to supply ports 31Bk, 31m, 31c,
It has a supply path supplied from 31y. Storage container 35
Is connected to the supply ports 31Bk, 31m, 31c, 31y of the toner container corresponding to the developing device performing the developing operation when any of the developing devices 4Bk, 4m, 4c, and 4y performs the developing operation, and supplies the toner to the developing device. To do.

The storage container 35 is pivotally supported by a storage container support base 37 via a pivot 36 as shown in FIG. The storage container support base 37 is fixed to the main body of the image forming apparatus via a stretchable slide rail 38. The storage container support 37 and the storage container 35 are the slide rails 3.
The expansion and contraction of 8 enables movement in the horizontal front-back direction with respect to the front surface of the main body of the image forming apparatus.

With these configurations, the toner container 30B
When replenishing the developer to k, 30m, 30c, 30y,
The storage container 35 is pulled out to the front side with respect to the front surface of the main body of the image forming apparatus to expose a supply port (not shown) from the main body.
You can easily replenish toner. Also, the storage container 3
5 behind the photosensitive drum 1 and the developing device 4Bk, 4m,
When performing maintenance of 4c, 4y, etc., as shown in FIG. 5, after the storage container 35 is pulled out toward the front, the photosensitive drum 1 and the developing devices 4Bk, 4m, 4c, 4c, 4c
Rotate until the front of 4y is exposed, ie about 180 °. By pulling out and rotating the storage container 35 in this manner, the unit behind the storage container 35 can be taken out from the inside of the main body, and the maintenance workability in the machine is improved.

However, when the developing device is not developing,
The hot partner supply port and the toner supply port of the developing device are
Since the structure is completely separated, the toner may be scattered from the opening and the inside of the device may be contaminated with the toner.

Therefore, the present embodiment has the following configuration. 1 to 3 are enlarged sectional views of a hopper and a developing device. 1 is a side sectional view taken along the line I-I in FIG. 4, showing a supply port 31 and a replenishment port of a toner accommodating portion 40 of the developing device so that the accommodating container can slide in the direction of arrow A in the figure with respect to the printer body. 41 is a stand-by state in which the toner storage section 40 is separated, FIG. 2 is an operation state of the printer section in which the toner storage section 40 of the developing device is moved in the direction of arrow B in FIG. Each state is shown.

Further, in each drawing, 32 is a supply port 31.
An outer wall portion made of an elastic material such as rubber or foamed polyurethane provided around the periphery of the conveying path 33, a conveying path for conveying the toner from the toner container 30 to the supply port 31, and 34 for driving a conveying screw in the conveying path 33. Is the gear. In addition, 4
Reference numeral 2 is an outer wall portion provided around the supply port 41, and the supply port 3
Like the outer wall portion 32 of No. 1, it is made of an elastic body such as rubber or polyurethane foam.

In FIG. 1, the supply port 31, the outer wall portion 32 of the hopper and the supply port 41, the outer wall portion 42 of the developing device are largely separated from each other, and the hopper is moved in the direction of arrow A in the figure for toner supply or device maintenance. It is possible to slide.

When the copying operation is started, the four developing devices 4y, 4c, 4m, 4Bk shown in FIG. 6 and the eccentric cam 24 that selectively brings each developing device closer to the photosensitive drum 1 are provided.
Development unit 15 including y, 24c, 24m and 24Bk
0 is an eccentric cam 151 as a means for moving the developing device.
a and 151b move in the direction of the arrow shown in FIG. 6, and the relationship between the hopper and the developing device changes from the standby state shown in FIG.
The printer operating state shown in FIG.

At this time, the supply port 31 enters the opening of the replenishment port 41, and the outer wall portion 32 has a positional relationship such that a part of the outer wall portion 42 covers the outside of the outer wall portion 42.
By reducing the gap between 1 and the supply port 41, it is possible to prevent the toner from scattering.

Further, during development, one of the eccentric cams 24y, 24c, 24m, and 24Bk operates according to the discolored color to bring the bearing portion of the developing sleeve 112 of the developing device into contact with the positioning plate 111, and the photosensitive drum. The developing sleeve 112 facing 1 is brought close to the photosensitive drum to a predetermined position,
The state shown in FIG. 3 is obtained.

At this time, the supply port 31 further enters the opening of the replenishment port 41, the outer wall portion 32 and the outer wall portion 42 are in close contact with each other, and the toner agitated in the developing device is prevented from scattering to the outside.

In this embodiment, the developing unit is integrally moved to reduce the gap between the hopper and the developing device when the printer is operated from the standby state. However, the hopper is moved in the same manner. It may be configured.

[0042]

As described above, the first embodiment according to the present application is described.
According to the invention, since the developer supply device can be moved between the developer replenishment position and the maintenance work position, the maintenance work can be facilitated, and the developer supply device can be moved by the means for moving the development device. Since the developing device is moved to a position where a part of the outer wall portion that covers the periphery of the supply port and a part of the outer wall portion that covers the periphery of the replenishment port overlap each other, It is possible to reliably prevent the developer from scattering to the surface.

According to the second aspect of the present invention,
Since the plurality of developing devices of the first invention are arranged, the developer of each color is replenished while preventing the developer from leaking to the plurality of developing devices as in the first invention. Moreover, maintenance work can be facilitated.

Further, according to the third invention of the present application, the developer supplying device and the developing device according to the first invention or the second invention are such that the developer supplying device is at the developer supplying position, When the developing device is at the developing position, one or both of the end surface of the outer wall portion that covers the periphery of the supply port of the developer supply device and the end surface of the outer wall portion that covers the periphery of the supply port of the developing device Or, since it has a positional relationship of abutting against either or both of the developer supplying devices,
It is possible to reliably prevent the developer from leaking when the developer is replenished.

[Brief description of drawings]

FIG. 1 is a diagram showing a state in which a supply port of a developer supply device and a supply port of a development device are separated from each other in an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which a part of an outer wall portion surrounding a supply port of a developer supply device and a part of an outer wall portion surrounding a supply port of a developing device overlap each other in an embodiment of the present invention. Is.

FIG. 3 is a diagram showing a state of a supply port of the developing device and a supply port of the developer supply device when the developing device according to the first embodiment of the present invention moves to a developing position.

FIG. 4 is a diagram showing a state in which the developer supply device according to the embodiment of the present invention is housed in the printer body.

FIG. 5 is a diagram showing a state in which the developer supply device according to the embodiment of the present invention is pulled out from the printer unit main body and rotated 180 °.

FIG. 6 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Photosensitive drum (image carrier) 4y, 4c, 4m, 4Bk Developing device 30 Toner container (developer supply device) 31 Supply port 32 Outer wall part 41 Replenishment port 42 Outer wall part 151a, 151b Eccentric cam (means for moving the developing device) )

Claims (3)

[Claims] 1. An image carrier, a developing device having a supply port for receiving a developer, and a developer supply device having a supply port for supplying the developer to the supply port, wherein the developing device is a non-developing device. In an image forming apparatus movably disposed between a position and a developing position, the developer supply device is movably disposed between a developer replenishing position to the developing device and a maintenance work position,
An outer wall portion that covers the periphery of the supply port of the developer supply device; and an outer wall portion that covers the periphery of the supply port of the development device, wherein the developer supply device is in the developer supply position, and the development device is When in the non-developing position, a means for moving the developing device to a position where a part of the outer wall portion covering the periphery of the supply port and a part of the outer wall portion covering the periphery of the replenishment port overlap each other. An image forming apparatus characterized by being provided. 2. The image forming apparatus according to claim 1, further comprising a plurality of developing devices. 3. A developer supply device and a developing device, wherein the developer supply device is at a developer replenishment position, and when the development device is at a development position, an outer wall that covers the periphery of the supply port of the developer supply device. Either one or both of the end surface of the developing unit and the end surface of the outer wall portion that covers the periphery of the supply port of the developing device have a positional relationship of abutting on either or both of the developing device and the developer supplying device. The image forming apparatus according to claim 1 or 2.