JPS6215570A - Color changeable developing device - Google Patents

Abstract

PURPOSE:To evade the alternation of the equipment arrangement of a copying machine and the size increase and cost rising of the machine by putting a color changeable developing device in the space in an equipment which is nearly as large as that of the developing device of a black-and-white copying machine. CONSTITUTION:An annular developer tank 20 is provided while fitted rotatably around the cylindrical part 5b of a developing container which contains the periphery of the end part of an impeller 4 rotatably. The developer tank 20 is partitioned into three sector-shaped chambers 22-24 by radial walls 21 and an opening 25 and a shutter 26 corresponding to opening parts 5c and 5d of the cylindrical part are provided axially to walls facing the developer container cylindrical part. The tank 20 is rotated by an unshown driving device through a transmission device to the position where the opening 25 of each chamber overlaps with both openings 5c and 5d of the developing container cylindrical part, and the shutter 26 is opened and closed through an unshown transmission device. Toner cartridges 31-35 which contain toner particles of three colors are provided in a longitudinal direction above the developing container 5 and internal toner is replenished into the developing device 5 through a supply roller.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a developing device for a single-color electrophotographic copying machine that uses a two-component developer and can change the developed color.

BACKGROUND OF THE INVENTION Recently, single-color copying machines have come on the market that are capable of copying not only black but also other chromatic colors such as blue, sepia, red, and other desired colors.

A common way to change the copy color is to replace the developing unit, but this method causes toner scattering when the developing unit is installed and removed, contaminating the inside and outside of the machine, contaminating the operator, and making operations cumbersome. This has the disadvantage that the color display means of the developing unit installed in the copying machine is complicated. moreover,
There are drawbacks such as intrusion of dust into the developing unit, reduction in developer life due to attraction of magnetic bodies such as clips and pins by the magnetic force of the development sleeve, image abnormalities, and reduction in reliability due to damage to the photoreceptor.

To improve this, one or several developing units of black and other chromatic colors are installed in the machine in advance along the photoconductor, and the copy color can be changed by operating a switch on the operation panel. Nishidamono is proposed. ``This method makes it easier to change the copy color, but the device becomes larger and costs inevitably increase.
If the size is reduced, the frequency of replacing and replenishing the developer toner in the black copy sump, which is the most frequently used, will increase, and the number of colors that can be replaced will be limited to two at most: black and one other color. I can't.

By the way, the inventor of the present invention first aimed to miniaturize the developing device of a black and white electrophotographic copying machine using a two-component developer, to ensure full stirring of the developer, and to enable the user to replace the developer. proposed a developing device with a new configuration.

As illustrated in FIGS. 4 and 5, the developing device includes a developing sleeve 2 disposed opposite to a photoreceptor drum 1, and a developer storage section that stores a two-component developer consisting of toner and carrier. , an impeller 4 provided in the reservoir 3 and having a plurality of conveying blades 4b radially disposed on a hollow shaft 4a over the entire length in parallel to the developing sleeve 2 is straddled within the developing container 5; A spiral developer moving member 6 is fixed to the impeller 4 so as to rotate integrally therewith, surrounding the conveying blade 4b over its entire length. Further, a conveyance screw 7 is provided inside the hollow shaft 4a so as to be driven to rotate in a direction that moves the developer in a direction opposite to the conveyance direction by the developer storage member B. Both end faces of the hollow shaft 4a are closed, and a developer flow, an inlet 4c1, and an outlet 4d are bored near the end of the peripheral wall. The impeller 4 to which the cutting and adjusting member 6 is fixedly extends slightly protrudes from the front side surface of the developer container 5, and the developer container side plate 5a is a cylindrical part surrounding this part to allow rotation of the impeller 4. A developer supply port 5c and a developer discharge port 5 are provided at the upper and lower parts of the cylindrical portion 5b, respectively.
d is drilled. A toner cartridge 8 is attached above the impeller 4 of the developer container 5, and a toner supply roller 9 is provided at the lower end of the toner cartridge 8.

During development, the impeller 4 is rotationally driven in the direction shown by the arrow in FIG. As is well known, the toner is attracted to the surface of the sleeve 2 by a magnet inside the sleeve 2, the layer thickness is regulated by a doctor 10, and the toner is conveyed to a developing position facing the photoreceptor drum 1, and the toner is applied to the electrostatic latent image on the photoreceptor drum 1. After development, the developer is returned to the developer reservoir 6 in the developer container 5 by the sleeve 2 and circulated. The developer separated by the doctor 10 is returned to the developer reservoir 6 along the separator 11, and the toner reduced by repeated development is replenished from the toner cartridge 8. The operations described up to this point are the same as before.

On the other hand, when the impeller 4 rotates, the developer moves little by little from the right to the left in FIG. It enters the shaft 4a from the inlet 4c provided at the end of the shaft 4a, moves from left to right by the rotation of the conveying screw 7 provided inside, and when it reaches the right end, it enters the shaft 4a from the outlet 4d to the outside of the hollow shaft. is discharged and circulated. As a result, the developer is sufficiently agitated and homogenized in the lateral direction together with the supplied toner, and the agitation device conventionally provided near the separator is no longer necessary, making it possible to downsize the apparatus.

The upper and lower openings 5c, 5d of the cylindrical portion 5b of the developer container 5, which surrounds the left end of the impeller 4 (the front side of the device), can be opened and closed independently by caps 12. As shown in the figure, when the lower opening 5d is opened and the impeller 4 and conveying screw 7 are rotated, the developer that has been moved to the left end by the developer moving member will fall from the opening 5d under its own weight, so the opening 5d The developer in the developer container 5 can be collected by attaching a container under the developer side receiver. Next, as shown in FIG. 7, when the lower opening 5d is closed and the upper opening 5C is opened, and the developer is fed from above, the developer enters the hollow shaft through the inlet 4C of the hollow shaft 4a and is transported. It is conveyed to the right by the screw 7, and the discharge port 4
The developer is stored in the developer storage section 3 from d. After all the supply agent is supplied, the developer is uniformly distributed and stored in the storage section 6 by continuing the development drive for a certain period of time.

Purpose The present invention solves the above-mentioned problems of the conventional color-changing two-command developing device. An object of the present invention is to provide a developing device for a monochrome electrophotographic copying machine.

Structure In order to achieve the above-mentioned object, the present invention has been proposed by the present inventor, in which a developer moving member is provided integrally around the periphery, a developer conveying screw is provided inside the hollow shaft, and the developer transfer member is provided on the front side of the developer container. It has an impeller with one end inserted into a cylindrical part protruding from the side wall, and by utilizing the structure of a black and white developing device with openings provided above and below the cylindrical part, the cylindrical part can be rotated. The inside is divided into a plurality of chambers by a radial wall, and each chamber is provided with an opening at a position corresponding to the opening of the cylindrical portion of the developer container and means for opening and closing the opening. Each of the chambers is a developer storage chamber of a different color, and the developer in the developer container can be changed in color, and the toner tank of each color can be used to store the developer in the developer container. The present invention is characterized in that the toner of the color can be selectively replenished into the developer container.

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a diagram showing the vicinity of a developer tank in an embodiment of the present invention. The rest of the structure is essentially the same as described above with reference to FIGS. 4 to 7, except for the black-and-white developing device and toner replenishment section proposed earlier by the present inventor.

As shown in FIG. 1, an annular developer tank 20 is rotatably fitted onto a cylindrical portion 5b of a developer container which rotatably includes an end portion of an impeller 4 therein. The developer tank 20 has radial walls 21 as shown in FIG.
The chamber is divided into six fan-shaped cross-sectional chambers 22, 23, and 24, and an opening 25 and a shutter 26 corresponding to the openings 5c and 5d of the cylindrical portion in the axial direction are formed on the wall facing the cylindrical portion of each developing container. It is provided. In this example, the shutter 26 is a rotary shutter whose end portion slides into contact with a cylindrical surface having openings in opposing portions. The six chambers 22, 23, and 24 are developer storage chambers of different colors, for example, black, blue, and red.

The tank 20 is rotated by a drive device (not shown) via a transmission device to a position where the opening 25 of each chamber overlaps both of the two openings 5c and 5d of the cylindrical portion of the developer container in the circumferential direction and held at that position. Ru. Further, the shutter 26 is also opened and closed via a transmission device (not shown).

Further, as shown in FIG. 3, toner cartridges 31', 32. ' 33 are provided so that toner inside the developer container 5 can be replenished via respective replenishment rollers. The replenishment roller of each toner cartridge is selectively activated only for the toner cartridge of the color of the developer currently filled in the developer container 5.

Since this device is configured as described above, when changing the developing color, first, the empty chamber of the developer tank 20 that should contain the developer of the color currently contained in the developer container 5 is placed directly below. When the developer tank 20 is rotated to the position, the opening 25 of the chamber is aligned with the lower opening 5d of the cylindrical portion 5b of the developer container, the shutter 26 is opened, and the developing device is operated. The developer in the developer container 5 is stored in the chamber of the developer tank 20 that is to contain the developer of that color by the same operation as when collecting the developer in the developing device proposed by the present inventor.

Next, the developer tank 20 is rotated to a position where the chamber containing the developer of the color to be changed is directly above, and the opening 25 of the chamber and the upper opening of the cylindrical portion 5b of the developer container are opened. 5
When the position of C is aligned and the developing device is operated, the developer of the color to be changed is transferred to The agent is supplied from the tank 20 into the developer container 5 .

When the supply of developer is completed, the shutter 26 is closed.

The series of operations described above are performed by key operations on the operation section of the copying machine.

The operation during development is as described above.

If the toner density drops below a predetermined range due to repeated development, only the replenishment roller of the toner cartridge of the developer color is operable, so that a predetermined amount of toner of that color is added to the developer container 5. will be replenished.

Since the toner cartridge filters 1, 32, and 33 of each color are arranged in a line in the longitudinal direction, the toner falls onto the developer directly below them, but in the developing device of the present invention, the developer is The toner is laterally moved and stirred by a developer moving member 6 and a conveying screw 7 provided in the toner, and the toner is supplied to the sleeve 2 with a uniform toner concentration. By arranging the toner cartridges 61, 52, and 36 in a line in the longitudinal direction, the space required for the toner cartridges can be the same as in conventional black-and-white copying machines, reducing component placement and cost. - It is possible to avoid rising.

Note that the six toner cartridges do not necessarily have to have the same capacity, and it is also possible to make the black toner cartridge, which is used more frequently, larger than the other color toner cartridges.

In addition to arranging the toner cartridges in a single row in the longitudinal direction, it is also possible to arrange the cartridges the entire length of the developing device in parallel, or to make only the toner cartridges replaceable. It is also possible to adopt a method such as attaching only one.

Effects As described above, according to the present invention, a color-changeable developing device can be housed in an interior space that is almost the same as that of a black-and-white copying machine. It is possible to avoid the increase in size and cost.

Further, since the developer tank is placed on the front side of the device and the tank capacity can be increased, it becomes possible to change colors among a large number of colors, and the color changing operation becomes easier.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the vicinity of the developer tank according to the embodiment of the present invention.
FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, FIG. 6 is a perspective view showing the arrangement of the toner cartridge of the embodiment, and FIG. 4 is a sectional view of the black and white developing device previously proposed. FIG. 5 is a partially cutaway side view of the impeller, and FIGS. 6 and 7 are sectional views illustrating its operation. 1... Photoreceptor 2... Developing sleeve 6.
...Developer reservoir 4...Impeller 4a...Hollow shaft 4c...Opening 5...Developer container
5a... Container side plate 5b... Cylindrical part 5c
, 5d...Opening 6...Developer moving part M7...
・Conveyance screw 20...Developer tank 21・
...Radial walls 22, 23.24...Each color developer storage chamber 25...Opening 26...Shutter (opening/closing means) 31.32. )3...Toner cartridges for each color (toner tank) Procedural amendment August 21, 1985

Claims (2)

[Claims] (1) a developing sleeve disposed opposite to the photoconductor, a developer storage section for storing a two-component developer consisting of toner and carrier, and a developer storage section provided in parallel to the development sleeve within the storage section;
The developer container includes an impeller having a plurality of conveying blades arranged radially along its entire length, and the developing sleeve holds and conveys the developer supplied by the impeller to form a latent image on the photoreceptor. In the developing device of an electrophotographic copying machine, the developer is supplied with toner to perform development, and the developer after the development is returned to the developer reservoir and circulated. A spiral developer moving member is fixed surrounding the impeller, and the shaft of the impeller is formed hollow, and developer inflow and discharge ports are provided on the circumferential walls at both ends of the impeller. A conveying screw for conveying the developer is provided in the cylindrical shape. Openings for supplying and discharging developer are provided at the upper and lower parts of the cylindrical part, respectively, and the cylindrical part is rotatably fitted onto the outside. The developer tank has a developer tank provided with an opening and a means for opening and closing the opening at a position corresponding to the opening of the cylindrical portion of the developer container, each chamber of which is a developer storage chamber of a different color, and the developer container is equipped with a developer tank. The color changeable device is characterized in that the color of the developer can be changed, and the toner tanks of each of the above colors are provided so that toner of the color of the developer in the developer container can be selectively replenished. Developing device. (2) The above-mentioned color toner tanks are arranged in a line in the longitudinal direction above the developer container, and each of the color toner tanks is provided with a means for replenishing toner to the developer container so as to be selectively operable. A developing device according to claim 1.