JPS60260968A - Developing device - Google Patents

Abstract

PURPOSE:To easily make developing agent resupplying operations which are always required when a developing device is used, by providing a means which detects a developer at a location where part of or all of developers are exchanged and moving a desired specific developer to the exchanging location. CONSTITUTION:In a developing device 4 which develops a photosensitive drum 1, developers 4Y, 4M, 4C, and 4BK of each color are held by a supporting body 4a under a removable condition and the device 4 is rotated by means of a central shaft 4b. Notched openings for taking out developers are provided in the side plate of a copying machine main body and the openings are closed by the doors of the developers. When, for example, the developer 4Y is positioned to the exchanging location of developers, a detecting plate 9 fixed to the central shaft 4b judges that the developer 4Y is at the exchanging location by reflecting light from a photointerruptor 20Y. On the other hand, when it is judged that one of the developers other than desired one is at the exchanging location, a motor M for driving the device 4 is rotationally driven from a control section and the desired developer is moved to the exchanging location. Therefore, the developing agent resupplying operation which is always required when a developing device is used can be made easily.

Description

Detailed Description of the Invention [Scope of Industrial Application] The present invention is applicable to multi-color (two colors or three or more monochrome colors) or full-color electrophotographic copying machines, computers,
It can be used in a color recording device constituting an output section of a facsimile machine or the like.

[Prior art]

For example, in a configuration in which a plurality of developing devices using toners of different colors are arranged on a single latent image carrier such as a photosensitive drum, a plurality of developing devices are arranged sequentially around the circumferential surface of the latent image carrier. and a plurality of developing units supported by a rotating body,
It has been proposed that by rotationally driving this rotating body, only the developing device corresponding to the desired color toner is opposed to the latent image carrier.

Particularly in the latter case, since one developing device always faces the latent image carrier, the circumference of the latent image carrier can be made as small as possible.

[Problems to be solved by the present invention]

By the way, as mentioned above, since a plurality of developing units are provided and each developing unit moves endlessly during the developing process, replacement of the developer and maintenance of the developing unit tend to become complicated.

Particularly, the present invention aims to facilitate the developer replenishment operation, which is a constant process when using the apparatus.

[Means for solving problems]

The present invention achieves the above object in a rotary developing device in which a plurality of developing devices are mounted on a rotating body and each developing device is rotated to a predetermined position during development to perform development, in which part or all of the developing devices are replaced. The apparatus includes means for detecting a developing device at a replacement position, means for displaying a display based on the result, and means for moving a desired specific developing device to the replacement position. Here, replacing part of the developing device refers to replacing the toner cartridge containing replenishment toner.
Replacing the entire developing device corresponds to taking out the entire developing device for maintenance.

〔Example〕

FIG. 1 shows a sectional view of essential parts of an electrophotographic copying machine for forming a pull-color copy image to which the present invention can be applied.

In the figure, a photosensitive drum IVi, which is a latent image carrier, rotates in the direction of the arrow. Around it are a charger 2, an exposure optical system 6,
A developing device 4, a transfer system 5, and a cleaning device 6 are provided. The optical system 6 includes a document scanning section 3a and a color separation filter section 6b. Further, the developing device 4 includes a yellow developing device 4M using yellow toner and a t± developing device using cyan toner.
A black developer 4Bk that uses black toner is integrally provided. Each developing device is a well-known developing roller 2 that conveys toner using a magnetic field, as disclosed in Japanese Patent Publication No. 55-20579 by the applicant.
The developing unit prevents the toner from scattering by the action of a magnetic field, and is detachably held on a support 4a as shown in the figure and rotates around a central axis 4b, thereby allowing the developing unit to be replaced with respect to the developing position. On the other hand, the transfer section 5 includes a drum 5 having a gripper 5a.
b, and a transfer discharger 5C inside thereof.

A full-color image is formed by sequentially transferring color toners onto a transfer material supported on the transfer drum, as in conventional copying machines. This transfer material is supplied from a cassette 7, and the transfer portion that has completed the transfer process is separated by a separating means 8, and reaches onto a tray 10 via a fixing device 9.

FIG. 2 is a perspective view of an embodiment showing a configuration for replacing a developing device of a rotary developing device to which the present invention is applied. The main body side plate 150 has a notch 11 for taking out the developer, and the notch opening is closed by a developer door 151. As mentioned above, each developing device 4Y,
It is equipped with 4M, 4C, and 4BK developing units, and can rotate as a whole.

FIG. 6 is a detailed view of the rotary developing device. There is a developing device position detecting section at the end of the central axis 4b of the rotating body 4, and photo interrupters 20Y and 20, which are detecting elements, are provided correspondingly to the developing device position detecting section.
M, 2DC, and 20Bk are attached to the main body side.

21Y, 21M in the diagram.

2IC, 218kl'i This is a switch/indicator used to rotate the desired developer to the replacement position, and is attached to the main unit.

To explain the operation of the above device to which the present invention is applied, first,
When the yellow developing device 4Y is located at the above replacement position, the detection plate 19Fi fixed to the central shaft 4b of the developing device 4
, in the position shown in FIG. At this time, since the detection plate 19 reflects the light from the photointerrupter 20Y attached to the main body side, the yellow developer 4
It is determined that Y is in the exchange position, and this jin is displayed on the display 21Y. FIG. 4 shows a block diagram showing details of the control section. If it is desired to move the magenta developing device 4M to the replacement position, the button 21M is pressed and the photointerrupter 20 determines which developing device is currently in the replacement position. At this point, the desired magenta developer 4
When M is in the exchange position, the indicator 21 is signaled and displayed.

On the other hand, if it is determined that there is a developing device other than the desired magenta developing device, a signal is sent from the control section to the drive motor M of the developing device, as shown in FIG. 4, and the developing device is rotationally driven.

Since the detection plate 19 also rotates integrally with this drive, the light from the photointerrupter 20M is reflected, and the detection signal from this photointerrupter is transmitted to the CPU via the 110 board.
1, the drive circuit that controls the rotation of the motor M is activated based on the CPU's judgment, and the rotation of the developing device is stopped. At the same time, the display 21M lights up or flashes to indicate that the magenta developer has come to the predetermined replacement position.

The above series of operations is similarly applied to the yellow developing device 4Y and other developing devices.

After the desired developer has been rotated to the replacement position, each desired developer can be taken out by opening the developer door 151. FIG. 5 shows the developing device door 151 in an open state, and in this state, the developing device door 151U also serves as a guide plate for pulling out. Also, this door 15
By attaching a rail to 1, it is possible to stably guide the developing device when pulling it out or inserting it.
The developing device is rotationally driven via gears 101, 102, and 103.

FIG. 7 is an explanatory diagram showing a method of arranging each photointerrupter 20 in another embodiment, and in the above embodiment,
The developing device replacement position is detected and displayed by arranging a photointerrupter as shown in FIG. This makes it possible to display not only the replacement positions of the developing units, but also the developing units 4Y, 4M, 4C, and 48k that are in contact with the photosensitive drum 1 for development. . In addition, Figure 7 is 20 Y',
20M'.

Reference numerals 200' and 20Bk' indicate photointerrupters for detecting and displaying the developing device at the developing position.

The purpose of selectively moving only the desired developing device to the replacement position in this way is to avoid problems such as when the image quality changes only for a specific color while using the device, or when the amount of toner remaining is low (this may occur). This corresponds to a case where the detection is detected by a detection means (not shown).In other words, in such a state, it is necessary to inspect a specific developing device or replenish toner, and for that purpose, the developing device must be removed or new toner must be replenished. Operation is required.

〔Effect of the invention〕

As explained above, according to the present invention, when replacing the developing device, it is possible to determine which developing device is in the replacement position without inspecting the inside of the main unit (it can be confirmed from the outside).
For example, it is possible to prevent a desired developing device from being moved to a replacement position, such as erroneously inspecting a normal developing device or replacing a developing device to which toner is to be replenished. Particularly in a color developing device, if toners of different colors are mixed, the mixed developing device becomes unusable, and the main unit becomes unusable unless the developing device is replaced.

That is, the present invention is particularly effective for a developing device in which the developing device is used by replacing the developing device with respect to the developing position.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a color electrophotographic copying machine to which the present invention is applied, FIGS. 2 and 5 are perspective views showing the developing device take-out position, FIG. 6 is a perspective view of the developing device and drive unit, and FIG. Figure 4 is a block diagram of the control section, Figure 6 is an explanatory diagram of the drive system of the developing device,
FIGS. 7A and 7S are explanatory diagrams showing an application example of the detection means. In the figure, 4 is a developing device, 20Y, 20M, 20C,
2QBk is a photointerrupter for identifying the developer, 21Y-21M, 21C, and 21Bk are display/switch members, and M is a motor.

Claims (1)

[Scope of Claims] A rotary developing device in which a plurality of developing devices are mounted on a rotating body and each developing device is rotated to a predetermined position during development to perform development; A developing device comprising means for detecting a developing device at a replacement position to be replaced, and means for moving a desired specific developing device to the replacement position based on the detection result.