JPS60211480A - Developing device - Google Patents

Abstract

PURPOSE:To select easily development of each color by forming developing tanks of toners of individual colors into one unit and arranging the developing tank of one optional color by a designating switch on an operation panel so that this developing tank faces a photosensitive body. CONSTITUTION:A photosensitive body 1 faces a developing unit part 2 after image exposure for the purpose of making a latent image visible. The developing unit part 2 is divided equally into three by partitioning members 4 which are formed into one body together with a member 30 stuck to a revolving shaft 3, and developing tanks 21A, 21B and 21C, developing rolls 22A, 22B and 22C, and toner cartridges 26A, 26B and 26C are provided in individual divided parts. A prescribed part of the developing unit part 2 faces the photosensitive body 1 by the designating switch on the operation panel.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a device for developing a latent image formed on a recording medium (photoreceptor, etc.) in electrophotography, and particularly to a developing device that can select various colors for development. Regarding.

<Prior Art> An electrophotographic copying machine forms an electrostatic latent image corresponding to an original image on a photoreceptor, which is a recording medium, and develops this latent image using colored toner. This developed toner image is transferred to a sheet of paper that is sent as appropriate, and this sheet of paper is sent to a fixing section, where the toner image on the upper surface is fixed. The above-mentioned colored toner is generally black. Recently, color toners, so-called red or blue toners, have been selected and used.

Conventionally, electrophotographic copying machines have only housed a developing device that uses one color of toner, but in order to obtain a large number of color copies, a developing device corresponding to each color must be prepared, and the desired color can be selected. A developing device containing toner is attached to the main body of the copying machine. Therefore, unless a developing device containing the desired toner is installed in the main body of the copying machine, it is necessary to replace the developing device each time. Therefore, not only is a device required to accommodate the developing device that is not installed, but it is extremely troublesome to replace the developing device while checking which color toner's developing device is installed in the copying machine. Work was being forced. Furthermore, it is common to install the wrong developing device as the desired one.

<Object of the Invention> An object of the present invention is to provide a developing device that eliminates the above-mentioned conventional drawbacks.

Another object of the present invention is to house all the developing devices corresponding to each color in the machine, and to position the corresponding developing device by specifying a desired color.

<Example> FIG. 1 is a sectional view showing a developing device according to the present invention. In the figure, reference numeral 1 denotes a drum-shaped photoreceptor, and before facing a developing unit, charging and exposure steps are provided facing the photoreceptor. This photoreceptor is uniformly charged to a specific polarity by a corona discharger (not shown) installed opposite to it, and then exposed to image light by an optical means (not shown) that scans the original, to coat its surface. It is well known that an electrostatic latent image is formed according to an image.

In order to visualize the latent image formed as described above, the photoreceptor 1 faces the developing unit section 2 after image exposure, whereby the latent image is developed with toner. In this embodiment, the developing unit section 2 has a structure that enables three-color copying, and is fixed to a rotating shaft 3 that is rotatably supported between the frames of the copying machine main body. For example, it is rotated counterclockwise in the figure in accordance with the rotation of . The developing unit section 2 is divided into three equal parts by a partition member 4 integrated with a member 30 fixed to the rotating shaft 3. Each developer tank described below is attached to a rotating member constituted by the partition member 4 and the like. The space divided into three by the partition member 4 is further divided into two by the intermediate partition member 5, and thereby divided into six.

Each of the six divided spaces will be described below as being divided into 60° increments. divided into three by the partition member 4,
Furthermore, one of the spaces divided into two by the intermediate partition member 5 has a
Developing tanks 21A, 21B, and 2IC containing developer are provided. Developer tank 21A.

2]B and 2IC are provided so as to be slidable in the direction of the rotating shaft 3 in the space divided by the partition members 4 and 5, and to be detachable. This developer tank 2]A', 21B.

All 2ICs have the same structure, and the structure will be explained below using 21A as an example.

2. A developing roller 22A is provided in the developing tank 21A for adsorbing the contained developer and transporting it to a developing area facing the photoreceptor 1. As is well known, the developing roller 22A includes a cylindrical non-magnetic sleeve and a magnet having a large number of poles on the circumferential surface. Therefore, the developing roller 22A, in which magnetic developer is attracted to the circumferential surface of the sleeve by the magnetic force of the magnet, and the developer in the attracted state is conveyed in the rotational direction by rotating the sleeve, corresponds to the magnetic pole of the magnet. A brush made of developer is formed in the portion, and this brush comes into contact with the electrostatic latent image surface of the photoreceptor 1 to perform development. Further, within the developer tank 22A, developer stirring rollers 28A, 24A, and 25A are provided. Further, 20A in the figure is a doctor that regulates the amount of developer adhered on the developing roller 22A.

Toner cartridges 26A, 26B, and 26C are detachably provided in a space divided by the intermediate partition member 5 in order to replenish toner in the developer tanks corresponding to the developer tanks. The intermediate partition member 5 is provided with a replenishment port 6 for replenishing toner. An opening is provided in the developing tank 21 facing the supply port 6, and stirring rollers 25 are provided respectively facing the opening. Also,
A toner discharge port is also provided on the toner cartridge 26 side, and the developer tank side toner is supplied through this port. As shown in FIG. 2, the toner cartridge 26 is provided with a slideable toner cover 28 that covers a toner outlet 27, and by removing the toner cover 28, toner can be replenished from the outlet 27. becomes.

As shown in FIG. 3, the toner cover 28 is used when inserting the toner cartridge 26 into the space of the developing unit section 2.
Insertion is regulated by the stepped portion 5-1 formed on the intermediate partition member 5, etc., and the cartridge 26 is pushed into the discharge port 2.
This structure is removed from 7. Moreover, the intermediate partition member 5
A roller 29 is provided at the replenishment port 6 provided in the developer tank 21 to replenish the toner from the toner cartridge 26 into the developer tank 21 by rotating.

The toner replenishment roller 29 is made of a porous member such as a sponge, and toner is stored in each hole, and when it faces the developer tank 21, the toner falls due to its own weight and is replenished.

According to the developing unit 2 configured as described above, each developing roller 22 faces the photoreceptor 1 by rotating the rotating shaft 3. In particular, the following description will be made assuming that the developer tank 21A performs development with black toner, 21B performs development with blue toner, and 21C performs development with red toner. In order to detect the position of each developing tank 21, reflective plates 7A and 7A are installed on the partition plate 4 as shown in FIG. , B, and 7C are provided. Optical sensors 8A, 8B, and 8C are provided corresponding to the reflecting plates 7A, 7B, and 7C, respectively. The optical sensor 8 is composed of a light emitting and a light receiving element, and when the reflecting plate 7 is at a predetermined position, light from the light emitting element is received by the light receiving element via the reflecting plate. The reflecting plate 7A reflects light from the light emitting element to the light receiving element of the sensor 8A when the developing tank 21A faces the developing position facing the photoreceptor 1. Further, the reflector 7B is connected to the sensor 8B, and the reflector 7C is connected to the sensor 8B.
is provided to position the developing tanks 21B and 2IC at the developing position of the photoreceptor 1, corresponding to the sensor 8C.

Each of the above-mentioned developer tanks is unitized into a space divided into three equal parts of one rotating member, and a rotating shaft 3 is used to rotate the developing tank.
As shown in Fig. 5, the frames 18 and 19 of the copying machine main body are
It is pivotally supported via a bearing 17 between them. In addition, the rotation axis 3
A transmission member 16 such as a sprocket or a gear is fixed to one end of the transmission member 16 to which rotational force from a drive motor is transmitted via a clutch or the like. Therefore, the developing unit section 2 is
When the desired developing tank is rotated via the transmission member 16 and faces the developing area of the photoreceptor 1, the sensor 8 moves to the corresponding reflecting plate 7.
By detecting this, rotation stop control is executed. In particular, although not shown, a selection switch for selecting a toner color for development is provided on the operation panel of the main body of the copying machine. For example, the switch may be provided corresponding to each color of toner, or one switch may be provided to control the rotating shaft 3 by 1/3 rotation each time a single change operation is performed. Therefore, if a selection switch is provided corresponding to each color of toner, the sensor 8 corresponding to the selected color toner becomes effective, and the rotation is controlled by the output of the sensor 8. That is, when the developer tank 21 of the selected color toner faces the photoreceptor 1, the sensor 8 detects the corresponding reflector 7, and the control is performed based on this signal.

Further, although not directly related to the present invention, the developing unit 2 is provided with a developing tank cover 9 that covers the developing tank when not in use, in order to prevent toner from scattering when the developing unit 2 rotates. The cover 9 is provided so as to cover the outer periphery of the developing unit (2), and is divided into six equal parts around the rotating shaft 3, for a total of four covers 9. Developer tank cover 9-1 is cover 9
-3, and the developer tank cover 9-2 is moved together with the cover 9-4. Each cover 9 is fixed to one end of the connecting rod 10, and is positioned so as not to come into contact with the developer brush portion.

The other end of the connecting rod 10 is connected to a rotating body 11 attached to the rotating shaft 3 via a directional clutch. Each is fixed at +2. For example, when the rotating shaft 3 rotates counterclockwise, the rotating body I+, 12 is rotated in accordance with the rotation. However, if the rotating shaft 3 is rotated clockwise, the shaft 3 will rotate idly. The rotating body 1] has a developer tank cover 9-1.
The other end of each connecting rod 10 of +93 is fixed, and the other end of each connecting rod 10 of developer tank cover 9-2+94 is fixed to the rotating body 12.

Further, each of the developer tank covers 9 is provided with a protrusion 13 for rotation control. In particular, as shown in FIG.
Solenoids 14 correspond to the protrusions 13 1, 13 3 of -1.9 3, and solenoids 15 correspond to the protrusions + 3-2 and + 3-4 of the covers 9-2 and 9-4.
is located. Solenoid 14.15 has its actuating piece 14.15 when de-energized. -1.15-□ is projected to a position where it locks with the protrusion 13, and is removed from the position where it locks with the protrusion 13 when energized.

The operation of the developing unit section 2 having the above-described structure will be explained below. Currently, the developing unit section 2 is performing development using black toner, and the developing tank 21A is connected to the photoreceptor 1.
It is assumed that it is facing.

Therefore, if development with blue toner is desired, a selection switch for that toner is operated. With this designation, resensor 8B
The sensor 8B specifically detects the reflection plate 7B. If the toner developing tank 21B of the desired color does not face the photoconductor 1 by operating the specified switch, the rotational force of the drive motor is transferred to the rotation transmission member 16 fixed to the rotation shaft 3.
(a sprocket, a gear, etc.), and the rotating shaft 3 is rotated in one direction (counterclockwise in the figure). Then, when the sensor 8B detects the reflective plate 7B, the rotation of the rotating shaft 3 is stopped based on the detection signal. Therefore, the developer tank 21B stops at a position facing the photoreceptor 1. In this case, the rotation angle of the rotation shaft 3 is 12o0, and the rotation position is controlled in response to a detection signal from a rotation angle detection means (not particularly shown).
It is stopped at a fixed position, that is, at a position where the photoreceptor 1 and the brush of the developing roller 22B are in contact with each other.

Further, although not directly related to the present invention, the operation of the viewing tank cover 9 will be explained. This keeps the solenoids 14 and 15 in a de-energized state in synchronization with the start of rotation of the rotating shaft 3.

Since the drive of the solenoid 14.15 is controlled by the signal output every 60 degrees from the rotating shaft 30 rotation angle detection means, the solenoid 14.15 is first rotated 60 degrees from the stopped state. is energized and the actuating piece 14
1.15-1 is retracted. If the solenoid 14.15 is rotated further by 60 degrees, the power to the solenoid 14.15 is released, and the actuating piece +4
-1 and 15-1 are projected. Therefore, the first 60
° When rotating, especially the actuating piece 15-1 by the solenoid 15
Since the developer tank cover 9-2 protrudes, the protrusion 13-2 of the developer tank cover 9-2 is engaged with the operating piece 15-1. The developer tank cover 9-2, 9-4 remains stopped at the position shown in FIG. 3, and only the rotating shaft 3 rotates by 60 degrees. On the other hand, since the developer tank cover 9-119-3 is not regulated, it is rotated by 60 degrees in accordance with the rotation of the rotating shaft 3. Therefore, the developer tank 21B is removed from the developer tank cover 9-4 and exposed. Moreover, the developing tank 21A, which was previously facing the photoreceptor 1,
enters the developer tank cover 9-2 and is covered.

After that, the solenoid 14 is rotated by 60 degrees of the rotating shaft 3.
．． 15 is energized, the actuating piece 14 1.15-1 retreats from the operating position, and each developer tank cover 9 rotates in accordance with the rotation of the rotating shaft 3. Then, when the sensor 8B detects the reflecting plate 7B, the rotation of the rotating shaft 3 is stopped in accordance with the output of the rotation angle detection signal output every 60 degrees. This causes the developer tank 21B to stop facing the photoreceptor 1. At this time, the solenoids 14 and 15 are de-energized, and in particular, the operating piece 14-1 engages with the protrusion 13-3 of the cover 9-3, and everything stops in this state. Like this, developer tank 2I
The unused portion of the developer tank 2 is covered with a developer tank cover 9, and the desired developer tank 2 is covered with a developer tank cover 9.
Only 1 is exposed and faces the photoreceptor 1.

If the developer tank 21B faces the photoreceptor as described above,
The electrostatic latent image formed on the photoreceptor 1 is developed with blue toner.

In this embodiment, a case has been described in which the selection switch corresponding to each toner color is selectively operated, but one developer exchange switch is provided and the developer unit is rotated by 1/3 rotation with one operation of this switch. It is also possible to stop the developer tank, to make the next developer tank face the photoreceptor, and to display the color of the opposing developer tank during operation. Further, although there are three types of developing tanks according to this embodiment, the present invention is not limited to this, and it is sufficient that at least two types or more are used.

<Effects of the Invention> According to the developing device of the present invention, one developing tank for toner of each color is provided.
Since the developing tank of any one color is placed in opposition to the photoreceptor using a designated switch on the operation panel, the development of each color can be easily selected and the operation is very simple.

[Brief explanation of the drawing]

! '15r Fig. 1 is a cross-sectional view showing a developing device according to the present invention, Fig. 2 is a cross-sectional view showing an example of a toner cartridge integrated unit, Fig. 3 is a side view showing an example when the toner cartridge is inserted (D - The figure is a diagram for explaining the operation of the developer tank cover, and FIG. 5 is a side sectional view showing the structure of the developer tank cover. 1: Photoreceptor 2: Developing unit 3: Rotating shaft 4: Partition member 5: Intermediate partition member 7 (7A, 7B, 7C): Reflector 8 (8A, 8B, 8
C): Sensor 2+ (21A, 2]B, 2IC): Developing tank 22 (22A, 22B, 22C): Developing roller agent Patent attorney Aihiko Fukushi (and 2 others) Basin

Claims (1)

[Scope of Claims] 1. A device for developing an electrostatic latent image formed on a recording medium with colored toner, comprising: a plurality of developer tanks provided corresponding to each color of the colored toner; a driving means for moving the tank to a developing position relative to the recording medium;
a sensor for detecting the position of the developer tank moved by the drive means; a switch for selecting a desired colored toner color for the developer tank; and an operation of the switch to operate the drive means to move the developer tank to the desired developer tank. A developing device comprising: a control means for stopping the operation when detected by a sensor. 2. The developing device according to claim 1, wherein the developing tank is divided into rotating members and unitized.