JPH03194567A - Color image forming device - Google Patents

Abstract

PURPOSE:To facilitate the exchange of toner, the maintenance of an image forming processing means and the handling of developing devices by enabling the plural developing devices having the plural kinds of toner whose colors are different to be exchanged and constituting them with a developing part and a toner hopper part. CONSTITUTION:A moving object frame 40, which can move the developing devices 2a-2d in a horizontal direction, can be moved horizontally according to the chrominance signal of the toner. Thus, the positions of the devices 2a-2c are moved in a shortest distance by linear movement. When the devices 2a-2c are exchanged, they can be taken out from the aperture part 21 of a main body 20. By obtaining a process cartridge with the aid of integrally constituting a photosensitive drum 8, a primary electrostatic charger 10 and a cleaning unit 11, the developing devices are easily exchanged.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a color image forming apparatus, and particularly to a developing device thereof.

"Prior art" In conventional devices of this type, R (red) and G (
The process involves forming a latent image corresponding to each color (green), B (brown), developing it with cyan, magenta, yellow, and black toner, and repeating the transfer for each color onto paper that is in close contact with the transfer drum. Is going. In addition, as an alternative method for conventional devices, units that include a developer, a photosensitive drum, a charger, and a cleaner for cyan, magenta, yellow, and black toners are lined up as many times as the number of toner colors, and each photosensitive drum is After forming a latent image corresponding to each color on the paper, it is developed and sequentially transferred onto the paper.

"Problem to be Solved by the Invention" However, in any of the above methods, it is necessary to arrange a large number of developing devices or to arrange the units of photosensitive drums and developing devices, which is not suitable for miniaturizing the device. . In addition, either method is difficult to replace toner, dispose of waste toner, maintain the charger, and be serviceable, making it unsuitable for use as a small, service-free color image forming apparatus.

SUMMARY OF THE INVENTION An object of the present invention is to provide a color image forming apparatus that is small in size and easy to replace toner.

Another object of the present invention is to eliminate the developing device (to facilitate maintenance of the image forming process means).

Still another object of the present invention is to facilitate handling of the developing device.

[Means for Solving the Problems] In the first aspect of the present invention, a plurality of developing devices each having toner of a different color are supported so as to be replaceable with respect to a developing position, and the developing devices are This color image forming apparatus is replaceable and includes at least a developing section and a toner hopper section.

A second aspect of the present invention is that the image bearing member facing the developing device is
The color image forming apparatus according to the first invention is characterized in that a process cartridge is formed together with at least a cleaning means.

A third invention of the present invention is described in the first invention or the second invention, characterized in that the developing unit has a partition member that partitions a developing section and a toner hopper section, and the partition member is removed at the beginning of use. This is an image forming apparatus.

"Example" Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an embodiment using the present invention.

In the figure, there are four developing units 2a and 2b having cyan, magenta, yellow, and black color toners.

A rotating frame 1 for rotatably supporting 2c and 2d (representative reference numeral 2) is indexed and rotated about a support shaft 3 in accordance with the timing of development.

As shown in FIG. 1, an example of the rotating frame 1 has both ends of a developing device holder 19 pivoted by bins 1b at four equally spaced positions around a rotating shaft 5. The rotating shaft 5 is a photosensitive drum 8
Both ends of the rotating shaft 5 are supported by the machine frame so as to be rotationally driven.

An auxiliary bin 5a parallel to the rotating shaft 5 is rotatably attached to the tip of an arm 5b fixed to the rotating shaft 5, and one end of the developer holder 19 is aligned with the bin 1d on a line passing through the bin 1b parallel to the arm 5b. It is pivoted. The distance between the rotating shaft 5 and the auxiliary bin 58 is equal to the distance between the pins lb and ld. The bins 5a and 1d and the rotating shaft 5 and the bin ld are connected by links (not shown).

As described above, each developing device 2 has arm 5b, bin 5a and 1d.
(not shown), bin lb.

A link (not shown) connecting the developer holder 19 supported by the developer holder 1d and the bin 1b to the rotating shaft 5 forms a four-bar parallel link. When the rotating shaft 5 is driven, the arm 5b rotates and the developer holder 19 19 rotates while maintaining the same posture, and the developing sleeve 31 rotates around the rotation center 3.

Therefore, when the rotating shaft 5 rotates 90 degrees, the developing device 2 rotates 90 degrees and moves in parallel. The developer holder 19 is designed to allow the developer 2 to be moved in and out in a direction perpendicular to the plane of FIG.

The configuration of each developing device 2 containing four color toners is the same,
Only the toner is different. A photosensitive drum 8 made of an infrared sensitized organic photoconductor is rotated in the direction of the arrow in the figure, and is evenly and uniformly charged by a primary charger 10 having a grid. Laser light 9, which exposes photosensitive drum 8 according to image information, is emitted from a semiconductor laser (not shown) and is made into parallel light by a collimator lens, and then enters polygon mirror 6, where it is reflected and scanned by rotating polygon mirror 6. . The light beam reflected by the polygon mirror 6 is focused by the optical lens system 7 and at the same time is given f-θ characteristics. The light passing through the optical lens system 7 is directed to the photosensitive drum 8 by the reflecting mirror 4.
The photosensitive drum 8 is scanned in the longitudinal direction of the photosensitive drum 8 in the form of a small spot. The electrostatic latent image on the photosensitive drum 8 is developed by the developing device 2a, and then the resist roller 1
A transfer charger 13 is fed in four pairs in synchronization with the photosensitive drum 8 and placed on the transfer material wrapped around the surface of the transfer drum 12.
Transcribed by °. Toner remaining on the photosensitive drum 8 is collected and stored in a cleaning unit 11. Thereafter, the photosensitive drum 8 is uniformly exposed by the exposure means 17. When a series of image forming operations on the photosensitive drum 8 are completed, the developing device 2b faces the photosensitive drum 8. Next, an image is created using the developing device 2b.

For this, a semiconductor laser is modulated according to an image signal corresponding to the color of the toner in the developing device 2b, a latent image is formed on the photosensitive drum 8, and then developed, and the latent image is wound around the transfer drum 12, which has rotated once after the previous process. Transfer material is transferred onto the toner image transferred in the previous process. The following process is the developer 2
This is the same as in case a.

In this way, an image forming process is performed for each of the four developing units 2,
Toners of four colors are layered on the transfer material on the transfer drum 12. The transfer material on which the four color toners have been transferred is separated from the transfer drum 12 by a separating claw 15 and transported to a fixing device 16.
is fixed and ejected outside the machine.

FIG. 3 is a sectional view of the developing device 2, showing an outline of its internal configuration. Seal members 36 that are peeled off during use are placed above and below the developing sleeve 31 to seal the toner hopper container 33 and the developing container 30.
It serves to protect the surface of the developing sleeve 31 and prevent foreign matter from entering the developing device 2.

Non-fn having 6R poles housed inside the developer container 30
The cylindrical developing sleeve 31 is adapted to engage with an external drive device (not shown) at a toner supply position facing the photosensitive drum 8 . A blade 32 is a developing sleeve 31 made of a metal having a magnetic property, such as iron or nickel-plated stainless steel with iron magnetism.
A narrow gap is formed between the developing sleeve 31 and the developing sleeve 31 . A toner hopper container 3 is placed above the developer container 30.
3 is provided, and a partition member 35 is detached from the toner popper container 33 by pulling toward the front side during use.
The toner 34 filled in the toner hopper container 33 is prevented from falling into the developer container 3o until it is used.

When color printing is performed, the toner in the developing device 2 gradually decreases, and there is no more toner on the developing sleeve 31 (then the entire developing device 2 must be discarded.)
Guide 30a of protrusions provided at o, toner hopper container 33
A guide 33a of a protrusion provided on the developer holder 19 is guided by an upper protrusion 19a and a groove 19b, and the developer 2 can be freely moved in and out in the direction of the paper of FIG.

Developing device 2 attached to rotating frame l as shown in FIG.
a, 2b, 2c, and 2d are main bodies 20 of the color image forming apparatus;
Since the opening 21 can be pulled out, it can be easily replaced. To further facilitate replacement, the toner hopper container 33 may be provided with a drawer portion 22, for example.

The image forming apparatus may be a process cartridge in which the photosensitive drum 8 that performs a part of the image forming process, the wide charger 1o, and the cleaning unit 11 are integrated. In this way, the photosensitive drum 8 and the developing device 2
This makes it easier to replace consumable parts such as, and at the same time, it can be made smaller, allowing maintenance by the user.

Further, in this embodiment, although the detection of the remaining amount of toner in the developer container 3o and the detection of the full state of waste toner in the cleaning unit have not been described, it is of course possible to provide these sensors.

By installing a toner remaining amount detection function, it becomes clear when to replace the developing device 2, and misprints can be prevented. By installing the remaining amount of waste toner sensor, you can easily know when to replace the process cartridge. As a method of detecting the amount of toner, a known piezo method or optical detection method, or a method of applying an AC voltage to an antenna wire and observing a change in conductance may be used.

In the above embodiment, four colors of yellow magenta, cyan, and black were used as toners, but three colors excluding black may be used. In this case, there are three developing devices 2, and one in the rotating frame.
It will be attached every 20 degrees.

Furthermore, although the above embodiments have been described using a laser beam printer that guides a laser beam to a photosensitive drum to write, it is natural that an analog copying machine may be used.

"Other Embodiments" FIG. 4 shows another embodiment according to the present invention. Since the same components as in FIG. 1 are numbered the same, details of the image forming process will be omitted.

Here, the developing units 2a, 2b, 2c, and 2d are attached to a movable frame 40 that is movable in the horizontal direction so as to be able to move in and out in a direction perpendicular to the paper surface of FIG. It will move left and right. By doing this, the developing units 2a, 2b, 2c, and 2d do not move in a circular motion (
Since it moves in a straight line over the shortest distance, it is possible to follow the movement of the developing device 2 position even if the movement is fast.

Further, when replacing the developing device, the main body 20 can be easily pulled out by opening the front part or by providing an opening 21 as shown in FIG. 2.

Also in this embodiment, the photosensitive drum 8, - wide charger 10,
By integrally configuring the cleaning unit 11 and using it as a process cartridge, replacement becomes easy.

[Advantageous Effects of the Invention 1] As explained above, a plurality of developing devices each having toner of a different color are supported so as to be replaceable with respect to the developing position, and the developing devices are replaceable. ,
By making the color printer consist of at least a developing section and a toner hopper section, the size of the color printer can be reduced.
Stability and ease of maintenance by the user are now achieved.

Furthermore, since the second aspect of the present invention is provided with a process cartridge, maintenance of the image forming apparatus excluding the developing device is facilitated. Furthermore, according to the third aspect of the present invention, an unused developing device can be easily stored and brought into use.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a color laser beam printer according to an embodiment of the present invention, FIG. 2 is a perspective view of a color laser beam printer according to an embodiment of the present invention, and FIG. 3 is a longitudinal cross-section of the developing device of FIG. 1. 4 are sectional views of another embodiment of a color laser beam printer using the present invention. 1.Rotating frame 2a, 2b, 2c, 2d.Developer 20
...Developer holder 21...Opening 40...Movement frame.

Claims (1)

[Scope of Claims] 1. A plurality of developing devices each having toner of a different color are supported so as to be replaceable with respect to a developing position, and the developing device is replaceable and at least A color image forming apparatus comprising a toner hopper section and a toner hopper section. 2. The color image forming apparatus according to claim 1, wherein the image bearing member facing the developing device forms a process cartridge together with at least a cleaning means. 3. The color image forming apparatus according to claim 1 or 2, wherein the developing unit has a partition member that partitions the developing section and the toner hopper section, and the partition member is removed at the beginning of use.