JPH0636109B2 - Development device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for a multicolor copying machine, and in particular, when a multicolor image is formed using a plurality of developing devices, each developing device is used. Independently of each other to achieve development of a desired color.

[Conventional technology]

In a conventional multicolor copying machine, a plurality of developing devices that separately store two or more color developers are arranged along the moving path of the image carrier,
In many cases, each developing device operates independently to obtain a desired color.

In this type of multi-color developing device, as a mechanical means for operating each developing device, for example, there is one configured as shown in FIGS. 3 and 4.

The developing device shown in FIG. 3 includes slide members 4 and 5 arranged at the rear of the developing devices 2 and 3 so as to be able to approach and separate from the image carrier 1 integrally with the developing devices 2 and 3, and the slide members. Cams 8 and 9 for pressing or releasing the back surfaces of the members 4 and 5 against the elastic force of the springs 6 and 7 toward the image carrier 1;
Rotatable shafts 10 and 11 to which the cams 8 and 9 are attached are provided.

In addition, as shown in FIG.
Mechanical clutches 12 and 13 that control the amount of rotation of 0 and 11, and solenoids 14 and 15 that control the on and off of the clutches 12 and 13, respectively.
Are provided on the shafts 10 and 11, respectively, and further, after several gears 16 for rotating the shafts 10 and 11 are interposed, they are connected to a drive motor 17.

[Problems to be solved by the invention]

In the above-mentioned conventional developing device, since it is necessary to provide an operating mechanism for each developing device, the device itself becomes complicated and large, and the control parameters for operating each developing device increase, and the sequence becomes complicated. There was a drawback. Moreover, there is a problem that the number of components used is large and the cost is high.

Further, in the image forming apparatus having a plurality of developing devices as described above, each developing device occupies a large space, has a nature contradictory to the demand for miniaturization accompanying the high performance of the device, and is limited. In addition to the need to arrange the operating mechanism of each developing device in the space, simplification and miniaturization of the operating mechanism are inevitable in view of the recent demand for light weight and low cost of the apparatus.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a plurality of developing devices in a sequentially developing position by one operating mechanism without providing an operating mechanism to each developing device. It is an object of the present invention to provide a developing device that can be moved between a developing position and a non-developing position.

[Means for solving problems]

The developing device according to the present invention has first and second developing devices which are vertically arranged so as to face the image carrier,
In a developing device configured to obtain a desired color by independently operating the developing devices to a developable position and a non-developing position, the rear side of the first and second developing devices. Is provided with one rotary shaft member along the longitudinal direction of the developing device, and the rotary shaft member is provided with at least two cams whose positions in the circumferential direction are different from each other in the axial direction, The first developing device is provided with an abutting portion that comes into contact with one of at least two cams provided on the rotary shaft member, and the second developing device is provided with at least the rotary shaft member. An abutting portion that comes into contact with the other of the two cams is provided, and due to the rotational deviation of the cam provided on the rotary shaft member, the developing device accommodating the developing toner of the desired color advances to the developable position and Position retention and other than the above It is configured to control the backward and waits to non-development position of the developing unit.

[Action]

In the present invention, an operating mechanism for moving the first and second developing devices close to or away from the image carrier is provided with one rotary shaft member provided on the back side of the first and second developing devices. ,
The rotary shaft member is provided with at least two cams, and the at least two cams are selectively brought into direct contact with the contact portions of the first and second developing devices to develop the desired developing device. Since it is configured to control advancing to a possible position and holding of that position, and retreat of the developing device other than the above to the non-developing position and standby, the structure is simple and does not occupy space. In addition to downsizing, at least two cams are selectively brought into direct contact with the abutting portions of the first and second developing devices to directly control the position of the developing device, so that a link mechanism is provided. Unlike the case where the eccentric rotational force of the cam is transmitted to a plurality of developing devices via the above, a transmission loss does not occur, and the desired developing device can be moved to a developing position or the like in a short time and with high accuracy.

〔Example〕

An embodiment according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing the overall configuration of the first embodiment, and FIG. 2 is a conceptual diagram showing the schematic configuration of the second embodiment.

First, a first embodiment of the present invention will be described with reference to FIG.

The first developing device 21 and the second developing device 22 arranged in the vicinity of the image carrier 20 are supported by support members 24 provided on both side surfaces, respectively. The support member 24 supports both the developing devices 21 and 22 with respect to the elliptical slide portions 24a and 24b formed on the supporting member 24 so that the slide pins 21a and 22a project from both sides of the developing devices 21 and 22. Respectively,
It is configured to be slidable in the direction of arrow 23 so that it can approach and separate from the image carrier 20.

Further, a single rotating shaft member 29 is provided behind the developing devices 21 and 22.
Are arranged. The rotary shaft member 29 includes a cam portion 30a that presses the leaf springs 25 provided on both sides of the back surface of the developing device 21, and a cam portion 30 that pushes the leaf springs 26 provided on both sides of the back surface of the developing device 22.
A pair of cams 30 integrally formed with b are fixed. Therefore, when the rotary shaft member 29 rotates in the direction of the arrow 36, the cam 30 also rotates at the same time, and the developing devices 21, 22 are both rotated.
The leaf springs 25 or 26 provided on both sides of the back surface of the are pressed.

The cam 30 is provided with cam portions 30a and 30b which are formed by offsetting the projecting portions at 180 ° opposite positions in the axial direction. The cam portion 30a springs the first developing device 21.
It is pressed against the elastic force of 27, and is brought close to the image carrier 20 to be in a developable state. On the other hand, the cam portion 30b is the second developing device.
22 is pressed against the elastic force of the spring 28, and the image carrier 20
It is configured so as to be in a developable state by being brought close to. Therefore, the cam portion 30a is the first developing device.
When the second developing device 22 is being pressed, the second developing device 22 is retracted by the spring 28 to the rear of the image carrier 20 and is on standby, and the cam portion 30b is pressing the second developing device 22. When the first developing device 21 is present, the first developing device 21 is retracted by the spring 27 to the rear of the image carrier 20 and stands by.

A mechanical clutch 31 is provided at one end of the rotary shaft member 29, and a lever 33 that swings by turning on and off a solenoid 34 is provided.
However, the cam portion 30 of the cam 30 attached to the rotary shaft member 29 by hooking the projecting claw portions 31a respectively provided at two positions on the circumferential surface of the clutch 31 facing each other 180 °.
It is constructed so that a or 30b can be stopped at a position where it presses the developing device 21 or 22 exactly as desired.

The rotary shaft member 29 is rotationally driven by a drive motor (not shown) after passing through a gear 32 connected to a mechanical clutch 31 in several stages.

Next, a second embodiment of the present invention will be described with reference to FIG.

The original on the original placement surface 41 is moved by the light source lamp 42,
The reflected image passes through the optical path 43 and is exposed to the image carrier 40 charged by the charger 44, and the latent image formed there is formed by the first developing device 45 or the second developing device 46. It is developed. In parallel with these operations, the copy sheets 48 accumulated in the cassette 47 are sequentially fed from the uppermost portion by the sheet feed roller 49, and are further fed after waiting for a certain timing by the registration roller 50 on the way. While being guided to the image carrier 40, the developing toner adhered to the drum of the image carrier 40 is transferred by the transfer charger 51, is fed to the fixing device 53, and is discharged to the tray 54. On the other hand, in the image carrier 40, the developing toner that did not contribute to the transfer is the cleaner.
52 and proceeds to the next step imaging process.

(Up to this point, it is the same as a general copying machine.) In the copying machine configured as described above, the first developing device
An example will be described in which the colors of the developing toners of 45 and the second developing device 46 are different and a two-color monochromatic copy is made.

When copying a document on the document placement surface 41 using the first developing device 45, replace the cam portion 55a of the cam 55 with the first developing device 45.
By rotating and controlling the back surface of the 45 to a position where it is pressed, the first developing device 45 moves closer to the image carrier 40,
Its position is maintained. On the other hand, the second developing device 46 is separated from the image carrier 40 by a spring (not shown), retracts, and stands by.

As a result, a copy of the same color as the developing toner of the first developing device 45 is obtained through the above-mentioned image process.

When copying is performed using the second developing device 46, which is the opposite of the above, the cam portion 55b of the cam 55 causes the second developing device 46 to move.
When rotated and controlled to the position where the back surface of the second developing device is pressed, a copy having the same color as the developing toner of the second developing device 46 can be obtained by the process similar to that described for the first developing device 45.

〔The invention's effect〕

According to the developing device of the present invention, one operating mechanism for moving the first and second developing devices close to or away from the image carrier is provided on the back side of the first and second developing devices. Of the rotary shaft member and at least two cams provided on the rotary shaft member, and by selectively abutting the at least two cams directly on the contact portions of the first and second developing devices, Since it is configured to control the progress of the desired developing device to the developable position and the holding of the position, and the retreating and waiting of the developing device other than the above to the non-developing position
Not only is the structure simple, it does not take up space, and downsizing of the developing device is possible.
And a case where the eccentric rotational force of the cam is transmitted to a plurality of developing devices via a link mechanism in order to perform desired position control of the developing device by selectively directly contacting the contact portion of the second developing device. As described above, the transmission loss does not occur, and the desired developing device can be moved to the developing position or the like in a short time and with high accuracy.

[Brief description of drawings]

1 and 2 show an embodiment of the developing device according to the present invention. FIG. 1 is a perspective view and FIG. 2 is a conceptual view. FIGS. 3 and 4 show a conventional example, FIG. 3 is a conceptual diagram showing an essential part of the configuration, and FIG. 4 is a schematic configuration diagram showing the drive mechanism of FIG. Reference numeral 1,20,40: Image carrier 2,21,45: First developing device 3,22,46: Second developing device 29: Rotating shaft member, 30,55: Cam 30a, 55a: Cam part , 30b, 55b: Cam part 27, 28: Spring

Claims (1)

[Claims] 1. A first developing device and a second developing device, which are vertically arranged so as to face an image carrier, each developing device independently operating to a developable position and a non-developing position. In the developing device configured to obtain a desired color by doing so, one rotary shaft member is provided on the back side of the first and second developing devices along the longitudinal direction of the developing device. The rotary shaft member is provided with at least two cams whose positions in the circumferential direction are different from each other in the axial direction, and the first developing device is provided with at least two cams provided on the rotary shaft member. The second developing device is provided with an abutting portion that abuts one of the cams, and the second developing device is provided with an abutting portion that abuts the other of at least two cams provided on the rotary shaft member. Depending on the rotational deviation of the cam provided on the shaft member, It is configured to control the advancing and holding of the position of the developing device accommodating the color developing toner to the developing possible position, and the retreating and waiting of the developing device other than the above to the non-developing position. And developing device.