JPH02226266A - 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]

- 11 above The present invention relates to an image forming apparatus such as a color recording device that constitutes the output section of a color electrophotographic copying machine, a computer, a facsimile machine, etc., and particularly relates to an image forming apparatus such as a color recording device that constitutes an output section of a color electrophotographic copying machine, a computer, a facsimile machine, etc. The present invention relates to an image forming apparatus having a developing device that is moved to a developing unit position with a latent image carrier to perform development.

[Natsutoyo Ushikari developing device is a multi-color image developing device that employs a reciprocating developing device in which a moving device is installed adjacent to the photosensitive drum of the image carrier and a plurality of developing units are mounted on the moving table of the moving device. A forming device has been devised. This type of image forming apparatus is different from an image forming apparatus that employs a side-by-side developing device in which multiple developing units are arranged in parallel close to each other on the surface of the photosensitive drum. Since development is performed in opposition to the latent image on the drum, it is possible to downsize the photosensitive drum and, by extension, the size of the color electrophotographic copying machine, and it is possible to correct the time decay of the latent image of each color. It has the advantage that it is not necessary. However, when the toner concentration of the developer in each developing unit decreases, it is necessary to automatically replenish toner into the developing unit. Conventionally, in a developing device using a magnetic brush method using a two-component developer consisting of toner and a carrier of magnetic powder, a toner chamber is provided in a developer container containing the developer.
When the developer toner concentration in the developer container falls below a predetermined concentration, toner is replenished from the toner chamber to the developer container. The larger the toner chamber is, the more replenishment toner can be stored, but naturally the developing unit becomes larger, and the entire developing apparatus becomes significantly larger. The large moment of inertia of large developing devices makes it extremely difficult, and practically impossible, to drive and control such devices at high speeds. Therefore, the toner chamber is usually made small, and it is conceivable to replenish the toner chamber as needed via a cartridge-type toner replenisher. However, in this method of replenishing toner to the developer container that employs toner replenishment to the toner chamber, when a large number of copies are required, the developer is stopped or driven to the toner replenishment position and the toner is refilled. It becomes necessary to frequently insert the replenisher into the developing unit and replenish the toner chamber with toner. Such work is not only extremely tedious for the operator, but also causes a significant reduction in copying speed. In addition, since the developing unit must be configured so that the toner replenisher can be easily attached and removed, it is difficult to expect a completely sealed structure, and vibrations or shocks may occur while the developing unit is moving, starting up, or stopping. This may cause toner to scatter from the developing unit into the machine. Such toner scattering not only stains the copying machine and the operator, but also causes the developer in each development unit to mix colors with each other, making it difficult to obtain a good quality copy image. Therefore, as shown in FIG. 5(a), the toner container l is fixedly installed in the main body of the copying machine, and the toner container l and the developing unit 2 are connected by a flexible screw 4 in a flexible pipe 3. It is conceivable to adopt a method of connecting with a built-in toner supply path 5 and replenishing toner. The pipe 3 of the supply path 5 includes a toner outlet 6 of the toner container 1 and a toner intake port 8 of the developer container 7 of the developer unit 2.
The screw 4 is fixed to a screw shaft 9 provided at the lower part of the toner container l, inserted into the pipe 3, and reaches the toner intake port 8 of the developer container 7. The screw shaft 9 is connected to a toner replenishment drive source 11 via a clutch 10 outside the toner container 1. Therefore, according to the above toner replenishment method, the replenishment path 5 changes its curvature as the developing unit 2 moves, and is displaced in the direction of movement of the developing unit 2 as shown in FIG. 5(b). However, it can follow the developing unit 2. Then, the screw 4 is rotated by the drive of the toner replenishment drive source, and the toner stored in the toner container 1 is cut out from the lower part of the container 1, conveyed through the pipe 4, and the toner is replenished into the developer container 7. . However, since the supply path 5 has a portion of the toner container 1 on the toner delivery roller 6 side that extends horizontally from the toner container 1, shocks to the supply path 5 occur when the developing unit 2 is started or stopped. Due to the swinging of the replenishment path 5 while the developing unit 2 is moving, toner flows out from the toner container 1 through the replenishment path 5, causing a phenomenon in which the developer container 7 is excessively replenished with toner. As is well known in the development system using a two-component developer, excessive supply of toner into the developer container 1 as described above causes toner scattering, fogging, etc., leading to image stains. Also, when refilling the toner container with new toner, shake the special toner replenishment bottle.
Although it is common to increase the fluidity of toner and replenish the toner container 1, it is also possible to replenish the toner by shaking the replenishment bottle or by dropping the toner from the replenishment bottle. A large amount of air enters between the toner particles, causing the toner to take on a liquid-like appearance, and there is a risk that the toner may flow past the toner container 1, through the air supply path 5, and into the developer container 7. Therefore, an object of the present invention is to transfer toner from corresponding toner containers to a plurality of developing units mounted on a moving device of a developing device without causing the toner to flow out from the toner containers due to vibrations or shocks during movement of the developing unit. An object of the present invention is to provide an image forming apparatus that can be replenished with toner and that can eliminate frequent replenishment of toner by making it possible to increase the capacity of the toner container. The above objects are achieved by the image forming apparatus of the present invention. To summarize, the present invention includes a plurality of developing units mounted on a moving device that is movable toward a developing unit position with an image carrier, and a plurality of toner containers respectively corresponding to the developing units. Installed immovably independently of the unit,
A developing device in which the toner inlet of the developing unit and the toner outlet of the corresponding toner container are connected by a toner supply path movable in the moving direction of the moving device that includes a built-in flexible toner conveying means. The image forming apparatus is characterized in that the toner container is installed below the moving device. Support 11 Hereinafter, one embodiment of the present invention will be specifically described based on the drawings. FIG. 1 is a vertical cross-sectional view of an image forming apparatus for forming a full-color copy image embodying the present invention. In the figure, a photosensitive drum 21 as a latent image carrier rotates in the direction of the arrow in the figure, and around it is a charger 22 and an exposure optical device 23.
, a developing device 24, a transfer section 25, and a cleaning device 26 are arranged. The document reading system 27 is a document scanning section 27.
The optical device 23 forms a color-separated electrostatic latent image on the photosensitive drum 21 according to a signal from the photoelectric element 27b. The developing device 24 includes a plurality of developing units, for example, a yellow developing unit 24Y using yellow toner, a magenta developing unit 24M using magenta toner, a cyan developing unit 24C using cyan toner, and a black developing unit 248 using black toner. It has four developing units. These developing units 24Y
etc. are mounted on the moving table 28 of the moving device, and the moving table 28
By moving in the direction of the arrow shown in the figure, each developing unit 24Y, 24M, 24C124BK is transferred to a developing section position facing the photosensitive drum 21, and develops the electrostatic latent image of each color formed on the photosensitive drum 21. . On the other hand, the transfer section 25 is composed of a dielectric drum 25b having a gripper 25a and a transfer discharger 25C inside the dielectric drum 25b, and full-color images can be produced in the same manner as in conventional copying machines.
This is achieved by sequentially transferring the toner images of each color on the photosensitive drum 21 obtained by development onto the transfer material supported on the drum 25b. This transfer material is transferred from the upper or lower cassette) 29a or the manual feed section 29b to the transfer section 2.
The transfer material that has been transferred is separated by a separating means 30.
After being separated and conveyed by and fixed in the fixing section 31,
It is stored on the tray 32. The movable table 28 on which the four developing units 24Y of the developing device 24, etc. are mounted is equipped with a rack gear 33 on the lower surface.
By driving a motor (for example, a stepping motor) M serving as a drive source, a desired developing unit can be transferred to a developing section position. The developing unit that has reached the developing section position is pushed up toward the photosensitive drum 21 by a lifting means (not shown), and becomes ready for development. In this figure, the developing unit position is below the photosensitive drum 21, and the yellow developing unit 24Y is in a developing state. When forming an image using monochrome or two-color toner, do not operate the elevating means for the unnecessary developing unit, but let it pass through the developing unit position while being separated from the photosensitive drum 21, and the desired developing unit will be formed. The developing unit is transported until it reaches the developing section position. The yellow developing unit 24Y has a developing container 34Y, as shown in FIG.
Since BK also has a similar configuration, only the yellow developing unit 24Y will be described below, and the others will be omitted). The developer container 34Y rotatably supports a first developer stirring screw 35 (see FIG. 3), a second screw, and a magnetic sleeve 37. The drive input part to the developing container 34Y is a manpower element 38 with a protrusion provided at the end of the screw shaft 6a of the second screw, and the input element 38 is connected to the drive system using the motor M as the drive source of the moving table 28. Power is transmitted through the The sleeve 37 is rotated in a predetermined direction via the gear 39 on the second screw shaft 36a, the relay gear 40, and the gear 41 of the magnetic sleeve 37. Further, at the rear in this figure (in the front direction of the image forming apparatus), rotational drive is gear-transmitted from the shaft end of the second screw shaft 36a to the screw shaft 35a of the first screw 35. Developing container 3 with first screw 35 and second screw
The feeding direction of the developer stored in 4Y is in the directions of arrows A and B, respectively, whereby the developer is circulated and transported while being stirred. The developer container 34Y has a cylindrical portion 42 that protrudes in the axial direction of the first screw 35, and the first screw 35 extends into the cylindrical portion 42. The upper part of the cylindrical part 42 has a cylindrical part 43 having an opening on the first screw 35, and the upper surface of the cylindrical part 43 is an inclined surface such that the rear side of the developing unit 24Y is the lowest. A sealing material 44 made of an elastic material such as urethane foam is provided on the inclined upper surface. This cylindrical part 43
An opening on the upper surface thereof is connected to a toner container 45Y via a toner supply path 48, which will be described later, and serves as a toner intake port for receiving toner. FIG. 3 shows a vertical sectional view of the vicinity of the developing unit 24Y and the toner container 45Y taken along a vertical plane passing through the axis of the photosensitive drum 21 (the left side in this figure is the front direction of the image forming apparatus). A toner container 45Y storing yellow toner is fixed to the main body of the image forming apparatus below the movable table 28, and is immovably installed independently of the developing unit 24Y (as shown in FIG. Toner containers containing black toner 45M and 45C145BK
will be installed in the same way). The toner container 45Y and the developing unit 24Y are connected by a toner supply path 48 having a flexible screw 47 built into a flexible pipe 46. The pipe 46 of the supply path 48 is connected to the toner container 4
The pipe 46 is made of, for example, a rubber hose layered with a curvature from the lower part of the toner container 5Y to the upper part of the developer container 34Y of the developing unit 24Y. A joint 4 is attached to the upper surface of the cylindrical portion 43 on the cylindrical portion 42 of the container 34Y.
It is connected via 9. The screw 47 is made of a flexible spring steel material, etc., and is fixed to a screw shaft 50 provided at the lower part of the toner container 45Y and inserted into the pipe 46.
6 and is guided upward into the joint 49. The screw shaft 50 is connected to an output shaft (not shown) of a toner replenishment drive source via a clutch 51 outside the toner container 45Y. As shown in FIG. 4, the joint 49 has an inclined cylindrical portion 49a that guides the upper end of the pipe 46 upward in the toner delivery direction, that is, upward in the direction of the cylindrical portion 43 on the cylindrical portion 42 of the developer container 34Y. , a vertical cylindrical portion 49b extending vertically downward from the slanted cylindrical portion 49a and abutting the slanted upper surface of the cylindrical portion 43;
The lower surface of the inclined cylindrical portion 49a is inclined to match the upper surface of the cylindrical portion 43. The length of the screw 47 may be such that it is at least exposed within the vertical cylindrical portion 49b of the joint 49. As shown in FIG. 3, the developer container 34Y is a support structure in which one end of the screw shaft 35a of the first screw 35 is supported by one side plate 28a of the movable table 28, and the other end of the screw shaft 35a is fixed to the movable table 28. By supporting with the plate 53,
It is attached and mounted on the moving table 28. Therefore, simply by removing the support plate 53 from the moving stage 28 and pulling out the developer container 34Y in the direction of the arrow in FIG. The developer container 34Y can be easily removed from the moving table 28 by itself. Further, contrary to the above description, simply by pushing the developer container 34Y onto the movable table 28, the drive system of the developer container 34Y and the toner supply path 48 are connected, and the developer container 34Y can be mounted on the movable table 28. Although the yellow developing unit 24Y has been described above, the same applies to the other color developing units 24M and 24C124BK. The image forming apparatus of the present invention is configured as described above. According to this, in order to form a multicolor image, the moving device of the developing device 24 moves the four developing units 24 mounted on the moving table 28.
Transfer Y, 24M, 24C124BK to the developing unit position with the photosensitive drum 21 in a predetermined order, and perform development.
At this time, according to the present invention, although the toner containers 45Y, etc. are immovable, the toner supply paths 48 from the toner containers 4'5Y, etc. each have a flexible screw 47 built into the flexible vibrator 46. Therefore, it is possible to change the curvature as the developing unit moves, to be displaced in the moving direction of the developing unit, and to follow the developing unit. Further, when the clutch 51 is activated by a toner replenishment signal from a developer toner concentration sensor (not shown) in the developer container and transmits the power of the toner replenishment power source to the screw 47 built in the toner replenishment path 48, the screw 47 rotates to cut out the toner stored in the toner container from the lower part of the toner container, and conveys the toner upwardly in the toner supply path 48 to the joint 49 through the toner outlet 52 of the toner container. The toner is dropped into the vertical cylindrical portion 49b of the joint 49 and replenished into the developer container. At this time, the toner supply path 48
Since the toner container and the developer container are completely sealed, it is possible to completely prevent toner from scattering to the outside from the supply path 48. In addition, since the toner is conveyed upward in the toner supply path 48, the toner does not flow out from the supply path 48 into the developer container due to vibrations or shocks when the developing unit is moving, starting, or stopping. The container is not overfilled with toner. Since the inclined cylinder portion 49a of the joint 49 is inclined upward in the toner transport direction, the effect of preventing the toner from flowing into the developer container is even more reliable. Further, according to the present invention, since the toner container is installed below the movable stage 28 of the developing device 24, the capacity of the toner container can be increased due to the installation space within the image forming apparatus, and therefore, toner can be frequently supplied to the toner container. There is no need to replenish. Further, the toner container is installed below the moving table 28,
By providing the toner supply path 48 and the drive system to the developer container at the rear of the image forming apparatus, the space on the front side of the image forming apparatus and the degree of freedom in design are expanded, making it easier to remove jams and maintain each unit and parts. It becomes possible to do this easily. As explained above, in the image forming apparatus of the present invention, the plurality of developing units mounted on the moving device of the developing device,
A plurality of toner containers containing toner to be replenished via replenishment paths each having a built-in flexible toner conveyance means,
Since it is installed below the moving device, it is possible to replenish the toner container with toner without causing the toner to flow out from the toner container to the developing unit due to vibrations or shocks during movement of the developing unit. Furthermore, since the capacity of the toner container can be increased, there is no need to frequently replenish the toner container with toner.

[Brief explanation of the drawing]

FIG. 1 is a vertical longitudinal sectional view showing an embodiment of an image forming apparatus of the present invention. 2 is a rear perspective view showing the yellow developing unit of the developing device in the image forming apparatus of FIG. 1. FIG. 3 is a vertical sectional view showing the vicinity of the developing unit and toner container shown in FIG. 2. FIG. FIG. 4 is an enlarged vertical sectional view showing a connecting portion of a toner supply path to a developer container of the developing unit shown in FIG. 3. FIG. FIG. 5(a) is a vertical cross-sectional view schematically showing the vicinity of a developing unit and a toner container of a developing device in a conventional image forming apparatus. FIG. 5(b) is a left side view of FIG. 5(&). 24: Developing device 24Y, 24M, 24C, 248: Developing unit 2
8: Moving table 34Y: Developing container 45Y: Toner container 46: Pipe 47: Screw 48: Toner supply path 49: Joint 50 varnish screw shaft

Claims (1)

[Claims] 1) A plurality of developing units are mounted on a moving device that is movable toward a developing unit position with a latent image carrier, and a plurality of toner containers respectively corresponding to the developing units are installed independently of the developing unit. The toner intake port of the developing unit and the toner delivery port of the corresponding toner container are connected by a toner replenishment path movable in the moving direction of the moving device that includes a built-in flexible toner conveying means. 1. An image forming apparatus having a developing device comprising: an image forming apparatus, wherein the toner container is disposed below the moving device.