JP2733370B2 - Electrophotographic equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus that visualizes an electrostatic latent image formed on a photoreceptor with toner particles, transfers the image to paper, and fixes the image by heat or pressure. Things.

2. Description of the Related Art Conventionally, an electrophotographic apparatus is mainly used as an apparatus using a dry toner, and has been practically used as many copiers, laser printers and the like, and has made remarkable development. In recent years, the demand for colorization has been increasing from the market in addition to monochrome, and color copiers have been put out.

The electrophotographic apparatus is an apparatus to which an electrophotographic process technology is applied, and visualizes an electrostatic latent image formed on a photoconductor having a photosensitive layer with toner particles. An electrophotographic apparatus employing a two-component developing method using a mixture of a toner and a carrier as a developer generally has a developing vat filled with a developer and a toner hopper for storing replenishing toner. The toner in the toner hopper falls into the developing vat by the rotation of the toner discharge roller, and is controlled so that the mixing ratio of the toner and the carrier in the developing vat is always kept constant. The toner filled in the toner hopper decreases as it is used, and some of the toner adheres to the inner wall of the toner hopper, causing toner blocking (solidification) or accumulating in a stagnation portion. Was. When toner remains in the toner hopper, the capacity of the toner hopper is substantially reduced. Therefore, various attempts have been made to reduce the toner remaining in the stagnation portion and the like, to completely replenish the toner in the toner hopper to the outside, and to effectively use the volume of the toner hopper.

 Hereinafter, a conventional electrophotographic apparatus will be described.

FIG. 6 is a schematic configuration diagram of a conventional electrophotographic apparatus, and FIG. 7 is an enlarged view of a main part of the conventional electrophotographic apparatus. FIG. 6, FIG.
In the drawing, reference numeral 1 denotes an image carrier having a resin belt such as polyethylene terephthalate as a base material and a photosensitive receiving layer such as selenium (Se) or an organic photoconductor (OPC) applied on the outer peripheral surface thereof in a thin film form. . The image carrier 1 is wound and stretched so as to have a vertical plane by two image carrier transport rollers 2 and 3, and a drive motor (not shown) drives the image carrier transport rollers 2 and 3. By driving, it is rotated in the direction of arrow A. The charger 4, the exposure optical system 5, black (B), cyan (C), magenta (M), and yellow (Y) are arranged on the peripheral surface of the belt-shaped image carrier 1 in the image carrier rotation direction indicated by the arrow A in the order. ) Developers 6B, 6C, 6M, 6 for each color
Y, an intermediate transfer member unit 7, an image carrier cleaning device 8, and a static eliminator 9 are provided. The charger 4 includes a charging wire 10 made of a tungsten wire or the like, a shield plate 11 made of a metal plate, and a grid plate 12. When a high voltage is applied to the charging line 10, the charging line 10 causes a corona discharge to uniformly charge the image carrier 1 via the grid plate 12. Reference numeral 13 denotes an exposure light beam of image data emitted from the exposure optical system 5. In the case of a laser printer, this exposure light beam 13 is transmitted to a host computer (not shown).
To form electrostatic latent images on the image carrier 1 corresponding to specific components among a plurality of predetermined color components. Each color developing device 6 includes a toner hopper 15 for storing toners 14B, 14C, 14M, and 14Y corresponding to each color.
B, 15C, 15M, and 15Y, and developing bats 18B and 18C for storing developers 17B, 17C, 17M, and 17Y, which are a mixture of toners 14B, 14C, 14M, and 14Y and a carrier 16 made of magnetic particles such as iron powder. ,
Black (B), cyan (C), and magenta (M) are arranged in order from the bottom on the vertical plane of the image carrier 1, which is composed of 18M and 18Y and stretched to have a vertical plane by the image carrier transport rollers 2 and 3. M), yellow (Y) color developing units 6B, 6C,
6M and 6Y are stacked and arranged. 19 is toner hopper 15
B, 15C, 15M, and 15Y are toner discharge rollers made of a highly elastic synthetic resin foam that supplies the toners 14B, 14C, 14M, and 14Y into the developing bats 18B, 18C, 18M, and 18Y, and the toner hopper 15B , 15C, 15M, and 15Y, both ends of which are rotatably supported on both sides to close the toner discharge port 20. 21 is the first
As shown in FIG. 10, the toner conveying member includes a toner conveying member 21a, a toner conveying member 21b, and a toner conveying member returning spring 21c, and rotating shafts provided at both ends of the toner conveying member 21a. 21d toner hopper 15B, 15
It is rotatably supported on both sides of each of C, 15M and 15Y.
Rotation shafts 21e provided at both ends of the toner conveyance member 21a are connected to rotation bearings 21f provided at both ends of the toner conveyance member 21b, and the toner conveyance member 21b rotates around the rotation shaft 21e about the toner conveyance member 21a. It is freely supported. Also,
The toner conveying member return spring 21c connects the toner conveying member 21a and the toner conveying member 21b, and keeps the toner conveying member 21b rotating about the rotation shaft 21e in a predetermined state. Reference numeral 22 denotes a second toner conveying member, which is formed of a wire or the like, is formed to be bent in a rectangular shape, and has a toner hopper 15 at both ends.
B, 15C, 15M, and 15Y, the first toner conveying member 21
It is rotatably supported similarly to. The first toner conveying member 21 and the second toner conveying member 22 are
B, 15C, 15M, and 15Y prevent toner 14B, 14C, 14M, and 14Y from blocking, and toner 14B, 14C, 14M, and 14Y.
To the toner outlet 20. Here, as described above, the first toner conveying member 21 is composed of two members and is bent in the middle because the capacity of the toner hopper 15 is increased without increasing the height of the body of the machine. This is because the capacity is effectively utilized, and this is particularly effective when a developing device such as a color electrophotographic apparatus is used in a stacked state. 27 is a toner hopper 15B, 15C, 15M, 15Y rotatably supported at both ends by each of the developing bats 18B, 18C, 18M, 18Y.
Toner 14B, 14 supplied through the toner outlet 20
C, 14M, and 14Y and the carrier 16 are mixed and stirred, and the toner 14
B, 14C, 14M, and 14Y are agitating rollers for charging and transporting to the developing roller 28. The toner 14B, 14C, 14M, 14Y and the carrier 16 conveyed in the direction of the developing roller 28 and the carrier 16 are developed by the magnetic force of the magnet roller 29 fixed in the developing roller 28.
The magnetic brush is sucked onto the outer periphery of the blade 28 and forms a magnetic brush. With the rotation of the developing roller 28, the magnetic brushes of the developers 17B, 17C, 17M, and 17Y come into contact with the image carrier 1, and a portion of the image carrier 1 where the electrostatic latent image is formed is applied to each color component. The corresponding toners 14B, 14C, 14M, and 14Y are attached to form toner images. The selection of the toners 14B, 14C, 14M, and 14Y is based on the separation / contact cams 39B, 39C, and 39 whose both ends are rotatably supported by the main body of the electrophotographic apparatus.
M and 39M are rotated in response to a color selection signal from a host computer (not shown), and a selected developing device, for example, 6B is brought into contact with the image carrier 1 to perform the operation. The remaining unselected developing units 6C, 6M, and 6Y are separated from the image carrier 1 by a tensile force of a separation spring (not shown). 40 is the toner 14B, 14C, 14M, 1 in the developing bats 18B, 18C, 18M, 18Y.
This is a toner density detector for detecting the mixing ratio of 4Y and carrier 16. The intermediate transfer body unit member 7 includes a belt-shaped intermediate transfer member 41 made of a conductive resin or the like, and an intermediate transfer member.
Two intermediate transfer member transport rollers 42 and 43 supporting
And an intermediate transfer roller 44 arranged to face the image carrier 1 with the intermediate transfer member 41 interposed therebetween to transfer the toner image on the image carrier 1 to the intermediate transfer member 41. Here, the surface circumference of the intermediate transfer member 41 is equal to the surface circumference of the image carrier 1. 45 is an intermediate transfer member cleaning device for scraping residual toner on the intermediate transfer member 41,
While the composite image is being formed on the intermediate transfer member 41, the intermediate transfer member 41 is separated from the intermediate transfer member 41, and comes into contact only when it is used for cleaning. A copy body cassette 46 stores a copy body 47. The copy bodies 47 are sent out one by one from a copy body cassette 46 to a paper transport path 49 by a half-moon shaped paper feed roller 48. Reference numeral 50 denotes a registration roller for temporarily stopping the copy body 47 so as to match the position of the composite image formed on the intermediate transfer member 41 with the copy body 47, and is in pressure contact with the driven roller 51. 52 is a paper transfer roller for transferring the composite image formed on the intermediate transfer member 41 to the copy body 47,
Only when the composite image is transferred to the copy body 47, it rotates in contact with the intermediate transfer member 41. Reference numeral 53 denotes a fixing device including a heat roller 54 having a heat source therein and a pressure roller 55, and a pressure and heat generated by the nipping rotation of the heat roller 54 and the pressure roller 55 to transfer the composite image transferred onto the copy body 47. Is fixed on the copy 47.

FIG. 11 shows the toner discharge roller 19 and the first toner conveying member.
FIG. 4 is a perspective view of a main part of a drive system of a second toner conveying member 22 and a toner discharge roller driving gear 23 that rotationally drives a toner discharge roller 19. Reference numeral 24 denotes a first toner conveying member driving gear that rotationally drives the first toner conveying member 21, and is connected to the toner discharge roller driving gear 23 via an idler gear 25a. Reference numeral 26 denotes a second toner conveying member gear for rotating and driving the second toner conveying member 22, which is connected to the first toner conveying member driving gear 24 via idler gears 25b and 25c. Here, the driving gear train for rotating and driving the toner discharge roller 19, the first toner transport member 21, and the second toner transport member 22 includes the toner discharge roller 19, the first toner transport member 21.
And the rotation speed of the second toner conveying member 22 is set to be equal.

FIG. 8 is a diagram showing a state of the detaching operation of the developing units 6B, 6C, 6M, and 6Y. FIG. 9 is a diagram showing a driving operation state of the developing units 6B, 6C, 6M, and 6Y. Power (not shown)
B, 6C, 6M, 6Y, which is a driving gear for transmitting to the developing devices 6B, 6C, 6M, 6Y, and which is one end of a shaft of the developing roller 28 when contributing to development. Is driven to rotate the developing roller gear 32 attached to the camera. Reference numeral 33 denotes an agitation drive gear, which supplies power from a drive source (not shown) to the developing device 6 via an agitation driven gear 34 while the electrophotographic apparatus is operating.
Transmission to the stirring idler gear 35 and the stirring roller gear 36 arranged in B, 6C, 6M, 6Y, and the stirring rollers of the developing units 6C, 6M, 6Y
Turn 27. Here, the developing roller gear 32 and the stirring roller gear 36 are not connected. Reference numeral 37 denotes a support member for supporting the stirring driven gear 34, which is supported by the main body of the electrophotographic apparatus so as to be rotatable around the axis of the stirring driving gear 33. The end of the support member 37 is given a moment in the direction of arrow C by a tension spring 38 on the side opposite to the side on which the stirring driven gear 34 is supported.

The operation of the electrophotographic apparatus configured as described above will be described below.

First, a voltage is applied to the charging wire 10 in the charger 4 connected to the high-voltage power supply to cause corona discharge, thereby uniformly charging the surface of the image carrier 1 to about -700v to -800v. Next, the image carrier 1 is rotated in the direction of arrow A to expose a uniformly charged surface of the image carrier 1 with a laser beam or the like corresponding to a predetermined color of a plurality of color components, for example, black (B). A light beam 13 is irradiated to form an electrostatic latent image on the image carrier 1. On the other hand, the separation / contact cam 39B is rotated by a color selection signal from a host computer (not shown) to push the developing device 6B containing the black toner 14B contributing to the development in the direction of arrow B, so that the image carrier 1 Abut With the movement of the developing device 6B, the developing roller gear 32 is connected to the driving gear 31 as shown in FIG. 8, and the developing roller 28 starts rotating. The toner density adjusting means including the stirring roller 27 and the toner density detector 40 is constantly driven. The other developing devices 6C, 6M, and 6Y are separated from the image carrier 1 and have respective developing rollers 28 in the developing devices 6C, 6M, and 6Y.
Has stopped. On the other hand, the respective stirring rollers 27 in the developing devices 6C, 6M, and 6Y are rotated by being driven from the drive transmission path of the stirring drive gear 33 and the stirring driven gear 34 through the stirring idler gear 35, and the stirring roller 27 and the toner density detection are performed. The toner density adjusting means including the device 40 is also driven. Development bat
The toner 14B and the carrier 16 in the toner carrier 18B are mixed and triboelectrically charged by the stirring roller 27, are attracted by the magnetic force of the magnet roller 29, form a magnetic brush, and are rotated by the developing roller 28 in the direction of arrow H so that the magnet 14 faces the image carrier 1. The roller 29 is transported to the contact position of the N pole. When a potential difference is applied between the developing roller 28 and the image carrier 1 while the magnetic brush of the developer 17B is in contact with the image carrier 1 at this contact position, the electrostatic latent image portion formed on the image carrier 1 The toner 14B adheres to the toner image to form a toner image, and the development is completed. With this development, the toner 14B adheres to the image carrier 1 and is consumed.
When the toner concentration detector 40 detects that the mixing ratio of the toner 14B and the carrier 16 in 8B becomes lower than a preset value, the toner discharge roller 19 is driven and rotated by the detection signal. Due to this rotation, the toner 14B attached to the surface of the toner discharge roller 19 is scraped off by the edge of the toner discharge port 20, and the toner 14B in the toner hopper 15B is supplied to the stirring roller 27 in the developing vat 18B through the toner discharge port 20. Then, the mixture is restored to a predetermined mixture ratio and a constant mixture ratio is maintained. The first unit disposed in the toner hopper 15B
As shown in FIG. 7, the toner transport member 21 and the second toner transport member 22 draw a locus of a circle shown by a dashed line with the rotation of the toner discharge roller 19, stir the toner 14B, and discharge the toner 14B. Conveyed above 19. The first toner conveying member 21 adjacent to the toner discharge roller 19 is
Toner 1 in toner hopper 15B onto toner discharge roller 19
To supply 4B, for example, when rotating from the state of i in the direction of arrow D and rotating to the state of j, the toner hopper curved portion 6a
And the toner conveying member 21b comes into contact with the toner conveying member 21b, and starts rotating about the rotating shaft 21e. When the rotation further proceeds, the contact between the toner hopper curved portion 6a and the toner conveying member 21b is released, and the toner conveying member 21b is returned to a predetermined state by the restoring force of the toner conveying member return spring 21c, and the state becomes k. After that,
The above operation is repeated to continuously supply the toner 14B in the toner hopper 15B to the toner discharge roller 19.

When the development is completed, the developing device 6B rotates the image carrier 1 by the 180-degree rotation of the separation / contact cam 39B and the tensile force of the separation / contact spring (not shown).
From the contact position to the separation position, the contact between the image carrier 1 and the magnetic brush is lost, and at the same time, the connection between the developing roller gear 32 and the driving gear 31 is released, and the rotation of the developing roller 28 is stopped. On the other hand, since the stirring roller 27 always applies frictional charge to the toner 14B and immediately responds to printing, the connection between the stirring idler gear 35 and the stirring driven gear 34 of the developing device 6B is configured not to be released. The power from the gear 33 is constantly transmitted and continues to rotate, the toner concentration detector 40 is also driven, and the toner concentration is adjusted. The toner image formed on the image carrier 1 by the developing device 6B is transferred to the intermediate transfer member 41 for each color by applying a voltage to the intermediate transfer roller 44.

Next, for example, when the color of cyan (C) is selected, the separation / contact cam 39C rotates, and this time the developing device 6C is connected to the separation / separation spring (not shown).
Image carrier 1 in the direction of image carrier 1 against the tensile force of
To start the development of cyan. In the case of a copying machine or a printer using four colors, the above-described developing operation is sequentially repeated four times, and the four colors B, C, M, and Y are formed on the intermediate transfer member 41.
To form a composite image. The composite image formed in this manner is applied to a paper transfer roller 52 by applying a voltage, and is collectively transferred from the copy body cassette 46 to a copy body 47 placed along a paper transport path 49 by pressure. The image is fixed by the heat of the heat roller 54 and the sandwiching pressure of the pressure roller 55 by the 53, and is output as a color image.

However, in the above-described conventional configuration, the toner discharge roller
19, a first toner conveying member 21 and a second toner conveying member 22
Are equal to each other, the first toner conveying member 21 and the second toner conveying member are placed on the toner discharging roller 19 more than the amount of toner supplied from the toner discharging port 20 to the developing bats 18B, 18C, 18M, and 18Y. There is a problem that the amount of toner conveyed by the toner 22 is larger and the toner is aggregated on the toner discharge roller 19 as the toner is consumed.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention solves the above problems by providing a discharge roller for supplying toner to a developing unit provided in a toner hopper for storing toner, and rotating the toner while stirring the toner by rotation. A plurality of toner conveying members for conveying the toner in a direction perpendicular to the shaft and conveying the toner from the toner hopper to the discharge roller, wherein the rotation speed of the toner conveying member at a position close to the discharge roller among the toner conveying members is adjusted. The rotation speed is set to be lower than the rotation speed of the discharge roller, and the rotation speed is set lower for the toner conveying member located farther from the discharge roller so that the amount of toner fed from each toner conveying member is smaller than the amount of toner sent out.

According to the present invention, the toner transporting member disposed at the position closest to the discharge roller is rotated at a rotation speed lower than the rotation speed of the discharge roller in the related art, and at a position far from the discharge roller. Since the arranged toner conveying member is rotated at a lower rotation speed so that the amount of toner fed to each toner conveying member is smaller than the amount of toner to be sent out, the toner hopper is developed at a position far from the developing means in the toner hopper. In the place closest to the means, the toner is frequently stirred.

Embodiment FIG. 1 is a schematic configuration diagram of an electrophotographic apparatus according to one embodiment of the present invention, FIG. 2 is an enlarged view of a main part of the electrophotographic apparatus according to one embodiment of the present invention, and FIG. FIG. 4 is a diagram showing a state of a separation / contact operation of the electrophotographic apparatus in the example, FIG. 4 is a view showing a driving operation state of the electrophotographic apparatus in one embodiment of the present invention, and FIG. 5 is an electrophotographic apparatus in one embodiment of the present invention. FIG. 3 is a perspective view of a main part of the drive system of FIG.

Here, the same reference numerals are given to the same components as those of the conventional electrophotographic apparatus, and the detailed description is omitted.

In FIGS. 2 and 4, reference numeral 56 denotes a first gear from the toner discharge roller driving gear 23 disposed at the end of the toner discharge roller 19;
A first transmission gear for transmitting a driving force to a first toner conveying member driving gear 24 disposed at an end of the toner conveying member 21;
57 is a second transmission gear for transmitting a driving force from the first toner conveying member driving gear 24 to a second toner conveying member driving gear 60 disposed at an end of the second toner conveying member 22; 2
To third toner conveying member
A third toner conveying member driving gear 61 disposed at an end of
A third transmission gear for transmitting the driving force to the third transmission gear. These drive gear trains set the rotation speed of the toner discharge roller 19 to v1, the rotation speed of the first toner conveyance member 21 to v2, the rotation speed of the second toner conveyance member 22 to v3, and the rotation speed of the third toner conveyance member 59 to v3. Assuming that the rotation speed is v4, the relationship is such that v1>v2>v3> v4.

The operation of the electrophotographic apparatus of the present invention configured as described above will be described below.

First, a voltage is applied to the charging wire 10 in the charger 4 connected to the high-voltage power supply to cause corona discharge, thereby uniformly charging the surface of the image carrier 1 to about -700v to -800v. Next, the image carrier 1 is rotated in the direction of arrow A to expose a uniformly charged surface of the image carrier 1 with a laser beam or the like corresponding to a predetermined color of a plurality of color components, for example, black (B). A light beam 13 is irradiated to form an electrostatic latent image on the image carrier 1. On the other hand, the separation / contact cam 39B is rotated by a color selection signal from a host computer (not shown) to push the developing device 6B containing the black toner 14B contributing to the development in the direction of arrow B, so that the image carrier 1 Abut With the movement of the developing device 6B, the developing roller gear 32 is connected to the driving gear 31 as shown in FIG. 3, and the developing roller 28 starts rotating. The toner density adjusting means including the stirring roller 27 and the toner density detector 40 is constantly driven. The other developing devices 6C, 6M, and 6Y are separated from the image carrier 1 and have respective developing rollers 28 in the developing devices 6C, 6M, and 6Y.
Has stopped. On the other hand, each of the stirring rollers 27 in the developing devices 6C, 6M, and 6Y is rotated by being driven from a drive transmission path of the stirring drive gear 33 and the stirring driven gear 34 through the stirring idler gear 35, and the stirring roller 27 and the toner density detector. The toner density adjusting means 40 is also driven. Development bat 18B
The toner 14B and the carrier 16 are mixed and triboelectrically charged by the stirring roller 27, are attracted by the magnetic force of the magnet roller 29, form a magnetic brush, and rotate the developing roller 28 in the direction of the arrow H so that the magnet roller opposes the image carrier 1. 29 N
It is transported to the extreme contact position. At this contact position, the developer
When a potential difference is applied between the developing roller 28 and the image carrier 1 while the magnetic brush 17B is in contact with the image carrier 1, the toner 14B adheres to the electrostatic latent image formed on the image carrier 1. To form a toner image, and the development is completed. With this development, the toner 14B adheres to the image carrier 1 and is consumed.
When the toner concentration detector 40 detects that the mixing ratio between the toner 14B and the carrier 16 in the toner concentration becomes lower than a preset value, the toner discharge roller 19B is driven and rotated by the detection signal. Due to this rotation, the toner 14B attached to the surface of the toner discharge roller 19 is scraped off by the edge of the toner discharge port 20, and the toner 14B in the toner hopper 15B is supplied to the stirring roller 27 in the developing vat 18B through the toner discharge port 20. Then, the mixture is restored to a predetermined mixture ratio and a constant mixture ratio is maintained. The first unit disposed in the toner hopper 15B
Toner transport member 21, second toner transport member 22, and third
As shown in FIG. 2, the toner transport member 59 described above draws a locus of a circle shown by a dashed line with the rotation of the toner discharge roller 19, stirs the toner 14B, and transports the toner 14B onto the toner discharge roller 19. When the toner 14B is transported onto the toner discharge roller 19, the first toner transport member 21 and the second toner transport member 2
2. The drive gear train is configured so that the rotation speed of the third toner conveying member 59 is reduced. Since the drive gear train is configured such that the rotation speed is reduced, excessive toner is not conveyed and aggregated on the toner discharge roller 19B. Further, since the rotation speed is reduced, the generation of fine powder toner due to the impact between the first toner transport member 21, the second toner transport member 22, the third toner transport member 59 and the toner 14B is reduced, and the first toner transport The driving force of the member 21, the second toner conveying member 22, and the third toner conveying member 59 can be reduced. The first toner conveying member 21 adjacent to the toner discharge roller 19 supplies the toner 14B in the toner hopper 15B onto the toner discharge roller 19, for example, rotates from the state of i in the direction of arrow D to the state of j. Then, the toner conveying member 21b comes into contact with the toner hopper curved portion 6a, and starts rotating around the rotation shaft 21e. When the rotation further proceeds, the contact between the toner hopper curved portion 6a and the toner conveying member 21b is released, and the toner conveying member 21b is returned to a predetermined state by the restoring force of the toner conveying member return spring 21c, and the state becomes k. Thereafter, the above operation is repeated, and the toner discharging roller 16
The toner 14B in the toner hopper 15B is continuously supplied.

When the development is completed, the developing device 6B is moved from the contact position with the image carrier 1 to the separated position by the 180-degree rotation of the separation / contact cam 39B and the tensile force of the separation spring (not shown). The contact between the developing roller gear 32 and the driving gear 31 is released at the same time, and the rotation of the developing roller 28 is stopped. On the other hand, since the stirring roller 27 always applies frictional charge to the toner 14B and immediately responds to printing, the connection between the stirring idler gear 35 and the stirring driven gear 34 of the developing device 6B is configured not to be released. The power from the gear 33 is constantly transmitted and continues to rotate, the toner concentration detector 40 is also driven, and the toner concentration is adjusted. The toner image formed on the image carrier 1 by the developing device 6B is transferred to the intermediate transfer member 41 for each color by applying a voltage to the intermediate transfer roller 44.

Next, for example, when the color of cyan (C) is selected, the separation / contact cam 39C rotates, and this time the developing device 6C is connected to the separation / separation spring (not shown).
Image carrier 1 in the direction of image carrier 1 against the tensile force of
To start the development of cyan. In the case of a copying machine or a printer using four colors, the above-described developing operation is sequentially repeated four times, and the four colors B, C, M, and Y are formed on the intermediate transfer member 41.
To form a composite image. The composite image formed in this manner is applied to a paper transfer roller 52 by applying a voltage, and is collectively transferred from the copy body cassette 46 to a copy body 47 placed along a paper transport path 49 by pressure. The image is fixed by the heat of the heat roller 54 and the sandwiching pressure of the pressure roller 55 by the 53, and is output as a color image.

As described above, according to the present invention, the toner conveying member disposed closest to the discharge roller is rotated at a rotation speed lower than the rotation speed of the discharge roller in the related art, and is far from the discharge roller. The toner transport member disposed at the position is rotated at a lower rotation speed so that the amount of toner fed is smaller than the amount of toner sent out of each toner transport member, so that the toner transport member is located farther from the developing unit in the toner hopper. On the other hand, the toner closest to the developing means is agitated with a lot of toner, and the toner conveying member is rotated at the same rotational speed as the discharge roller in accordance with the location closest to the developing means which requires the most toner agitation. In comparison with the case where the whole toner inside is uniformly stirred, a place far from the developing means where the stirring of the toner is not so necessary is used. When the stirring is performed at a position closest to the toner conveying member, the rotational driving torque for driving a plurality of toner conveying members is reduced. With a small driving torque, the toner can be prevented from being supplied to the developing unit with the toner adhered to each other, and the image quality of the toner image can be prevented from deteriorating.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electrophotographic apparatus according to one embodiment of the present invention, FIG. 2 is an enlarged view of a main part of the electrophotographic apparatus according to one embodiment of the present invention, and FIG. FIG. 4 is a diagram showing a detaching operation state of the electrophotographic apparatus, FIG. 4 is a diagram showing a driving operation state of the electrophotographic apparatus in one embodiment of the present invention, and FIG. 5 is a driving of the electrophotographic apparatus in one embodiment of the present invention. FIG. 6 is a schematic configuration diagram of a conventional electrophotographic apparatus, FIG. 7 is an enlarged view of a main part of the conventional electrophotographic apparatus,
FIG. 8 is a diagram showing the state of the separation / contact operation of the developing devices 6B, 6C, 6M, 6Y, FIG. 9 is a diagram showing the driving operation state of the developing devices 6B, 6C, 6M, 6Y, and FIG. Enlarged view of toner transport member 21, eleventh
FIG. 3 is a perspective view of a main part of a drive system of a toner discharge roller 19, a first toner conveying member 21, and a second toner conveying member 22. 1 ... image carrier, 2,3 ... image carrier transport roller, 4 ...
Charger, 5 ... Exposure optical system, 6B, 6C, 6M, 6Y ... Developer, 6
a: curved portion of toner hopper, 7: intermediate transfer member unit, 8: cleaning device for image carrier, 9: static eliminator, 10: charged wire, 11: shield plate, 12: grid plate, 13 ...... Exposure light beam, 14B, 14C, 14M, 14Y ... Toner, 15
B, 15C, 15M, 15Y ... toner hopper, 16 ... carrier, 17B, 17C, 17M, 17Y ... developer, 18B, 18C, 18M, 18Y ...
Developing vat, 19 toner discharge roller, 20 toner discharge port, 21 first toner conveying member, 21a toner conveying member, 21b toner conveying member, 21c toner conveying member return spring, 21d …… Rotary axis, 21e …… Rotary axis, 21f ……
Rotary bearing, 22 second toner conveying member, 23 toner driving roller driving gear, 24 first toner conveying member driving gear, 27 stirring roller, 28 developing roller, 29 magnet Roller, 30 doctor blade, 31 driving gear, 32 developing roller gear, 33 stirring drive gear, 34
… Agitation driven gear, 35… agitation idler gear, 36… agitation roller gear, 37… support member, 38… tension spring, 39B,
39C, 39M, 39Y …… Separation cam, 40 …… Toner density detector, 4
1 Intermediate transfer member, 42, 43 Intermediate transfer member transport roller, 44 Intermediate transfer roller, 45 Intermediate transfer member cleaning device, 46 Copy body cassette, 47 Copy body, 48
…… paper feed roller, 49 …… paper transport path, 50 …… registration roller, 51 …… driven roller, 52 …… paper transfer roller, 53…
... Fusing unit, 54 ... Heat roller, 55 ... Pressurizing roller, 56
... A first transmission gear, 57... A second transmission gear, 58... A third transmission gear, 59... A third toner conveying member, 60... A second toner conveying member driving gear, 61. ... A third toner conveying member gear.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-144375 (JP, A) JP-A-60-163067 (JP, A) JP-A-64-21468 (JP, A) JP-A 59-144 100472 (JP, A) Actually open sho 59-136648 (JP, U)

Claims (1)

(57) [Claims] A toner attaching member to which toner adheres in accordance with image information; developing means for applying toner to the toner attaching member; a toner hopper for accommodating toner; and a toner provided in the toner hopper to a developing means. A discharge roller for supplying, and a plurality of toner conveying members that stir the toner by rotation and convey the toner in a direction perpendicular to the rotation axis, and convey the toner to the discharge roller by the toner hopper; The rotational speed of the toner transport member closer to the discharge roller of the toner transport member is lower than the rotational speed of the discharge roller, and the rotational speed of the toner transport member farther from the discharge roller is reduced. The amount of toner fed to each toner conveying member is made smaller than the amount of toner sent out. Electrophotographic apparatus according to claim.