JPH0619623B2 - Multicolor developing device - Google Patents

Description

The present invention relates to a multicolor developing device used in a multicolor image recording device, and more particularly, to a multicolor developing device which rotates and electrostatically forms a surface by electrostatic latent image forming means. A developer carrying carrier that is disposed around an image forming body on which a latent image is formed, and that attaches toners of different colors and the same charging polarity to the electrostatic latent image of the image forming body.
A developer reservoir for supplying a developer onto the developer carrying carrier;
The present invention relates to a multicolor developing device including a plurality of developing devices including a toner hopper for storing toner and a toner replenishing means for feeding the toner of the toner hopper to a developer reservoir.

[Prior art]

The multicolor image recording apparatus includes one that superimposes toner images on recording paper and one that superimposes toner images on an image forming body.

The recording apparatus of FIG. 1 records a multicolor image by superimposing toner images of different colors on a recording paper. In this recording apparatus, an electrostatic latent image for one color separation formed on the surface of the photoconductor of the image forming body 1 rotating in the direction of the arrow by an appropriate means is transferred by a multicolor developing device 2, for example, by a developing device A. The toner image of the corresponding color is developed, and the toner image is transferred by the transfer device 5 to the recording paper held by the gripper 4 on the transfer drum 3 and then fixed by the fixing device 6. Then, again, an electrostatic latent image for another color of color separation is formed on the surface of the image forming body 1, and this time, the developing device B develops a toner image of a corresponding color, and the toner image is the same as before. A multicolor image is recorded by transferring and fixing onto a recording paper, superimposing it on the previous toner image, and repeating this for all colors of color separation.

Each of the developing devices A to D of the multi-color developing device 2 has a structure as shown in FIG. 2, 21 is a developer carrying carrier composed of a developing sleeve and a magnet body inside, and 22 is a developer reservoir. Two
3 is a stirring rotary blade, and 24 is a toner replenishing roller that replenishes the toner from the toner hopper 25 to the developer reservoir 23.
When the developer transport carrier 21 operates to develop the electrostatic latent image on the image forming body 1, the toner replenishing roller 24 also rotates so that a constant amount of toner is kept in the developer reservoir 23. There is.

The recording apparatus shown in FIG. 3 records a multicolor image by superposing toner images on the image forming body 1. In this recording apparatus, the image forming body 1 has a structure in which a photosensitive layer is provided on a grounded conductive substrate and a transparent insulating surface layer is provided on the photosensitive layer. It is charged by a primary charger 7 composed of an irradiating lamp 7a and a corona discharger 7b, and further charged by a secondary charger 8 composed of a corona discharger. A laser beam scanner 9 including an acousto-optic modulator, a rotating polygon mirror, an f-θ lens for image formation, and the like makes an image exposure for one color incident, and an electrostatic latent image formed by the laser beam scanner 9 is formed in the multicolor developing device 2. For example, the surface of the image forming body 1 which has been developed into a toner image of a color corresponding to image exposure by the developing device A, and the toner image is formed on the surface of the other developing devices B to D, the pre-transfer charger 10, the pre-transfer charger 10, The exposure lamp 11, transfer device 5, cleaning device 13, etc. Then, it is charged again by the primary charger 7 and the secondary charger 8 or is passed through them, and again, an image exposure for another color is made incident by the laser beam scanner 9 and thereby, The formed electrostatic latent image is developed into a toner image of another color by the developing device B this time, and the above is repeated. Finally, when the electrostatic latent image is developed by the developing device D, the image forming body 1 is formed. A multicolor toner image is formed on the toner image, and the toner image is easily transferred by the pre-transfer charging device 10 and the pre-transfer exposure lamp 11, and is transferred to the recording paper P by the transfer device 5 and fixed. A multicolor image is recorded by being fixed by the container 6. In addition,
The surface of the image forming body 1 on which the transfer of the multicolor toner images has been completed is destaticized by the destaticizer 12 including the destaticizing lamp 12a and the corona discharger 12b, and the residual toner is removed by the cleaning device 13. Then, the multicolor image recording process described above is again performed. The static eliminator 12 may be operated each time development is performed, when the primary charging device 7 and the secondary charging device 8 are charged during each electrostatic latent image formation, or the pre-transfer charging device. 10 or the pre-transfer exposure lamp 11 may be used instead.

The developing devices A to D in the multicolor developing device 2 of this recording apparatus
Has the structure as shown in FIG. 4, and the same reference numerals as those in FIG. 2 denote the same functional members. In the developing device of FIG. 4, the layer thickness of the developer layer formed on the developing sleeve 21a is adjusted by the layer thickness regulating blade 26 so as not to disturb the toner image previously formed on the image forming body 1. Therefore, it is formed to be thinner than the gap between the developing sleeve 21a and the image forming body 1,
By applying a bias voltage to the developing sleeve 21a by the bias power supply 28, a bias electric field having an oscillating component is generated between the substrate and the image forming body 1 whose ground is grounded. Toner is ejected from the layer to develop the electrostatic latent image on the image forming body 1. 21b is a magnet body, 2
7 is a developing sleeve 21a for the developer layer after passing through the developing zone.
The cleaning resistor 29, which is removed from the developer pool 23 and is reduced to the developing pool 23, is a protective resistor. The developing sleeve 21a rotates counterclockwise or stands still, the magnet body 21b stands still or rotates clockwise, and the developer layer formed on the developing sleeve 21a by one or both rotations is conveyed in the arrow direction. The toner replenishing roller 24 replenishes the toner when the developer carrying carrier 21 is operated, as in the developing device shown in FIG.

In the above-described multicolor image recording apparatus, when a large number of multicolor images are repeatedly recorded, the color toners of other developing devices are gradually mixed into the developing pools 23 of the developing devices A to D of the multicolor developing device 2. However, when an image is recorded, the color becomes conspicuous. Therefore, conventionally, the developer in which the color mixture has occurred is taken out and the developer in the developer reservoir 23 is replaced with a new developer. This work is not possible for general users, and it is a troublesome work for a professional service person, and it requires a place and tools to perform the work.
Further, there is a fear that the developer may be mistakenly put in.

A device that automatically replaces the developer is conceivable, but
The apparatus is considerably complicated, large in cost and large in size, and reliability is also a problem, which is unsuitable for a medium-sized recording apparatus or a small-sized recording apparatus.

[Object of the Invention]

The present invention, when color mixture occurs in the developing device of the multi-color developing device, even the user can easily return the developer in the developer reservoir to a state without color mixture, and further, without requiring a complicated device, It is an object of the present invention to provide a multi-color developing device without increasing the size of a recording device.

[Structure of Invention]

The present invention is arranged around an image forming body that is rotated to form an electrostatic latent image on the surface by the electrostatic latent image forming means, and the electrostatic latent images of the image forming bodies are different in color from each other. Toners having the same charge polarity are attached to the developer carrier, a developer reservoir for supplying the developer onto the developer carrier, a toner hopper for storing the toner, and a toner for feeding the toner in the toner hopper to the developer reservoir. In a multi-color developing device of a multi-color image recording device comprising a plurality of developing devices provided with replenishing means,
The operation mechanism of the developer carrying carrier and the toner replenishing means of each developing device is operated only to remove the toner in the developer pool, and a predetermined amount of toner is stored in the developer pool in which the toner is depleted. There is provided a multicolor developing device characterized by being configured so that it can be switched to the operation of only the toner replenishing means for this purpose. With this structure, the above object is achieved.

〔Example〕

The present invention will be described with reference to FIGS. 1 to 4. The multicolor developing device 2 of the present invention can be separated from the operation of the developer carrying carrier 21 and the toner supply roller 24 can be stopped. It can also be rotated. This is because a proper connecting / disconnecting means such as an electromagnetic clutch is provided in the rotation transmission path to the toner replenishing roller 24, and when the toner replenishing roller 24 is separated, the toner is replenished from another rotation source through a similar connecting / disconnecting means. The rotation can be easily transmitted to the roller 24. In such a multi-color developing device of the present invention, when a color mixture of the developer occurs in the developer pool 23 of the developing devices A to D, the toner replenishing roller 24 is not stopped even if the developer carrying carrier 21 is operated. Separate it so that it becomes ゝ. When developing in that state,
The toner in the developer pool 23 disappears immediately, and eventually the development is stopped. Then, next, only the toner replenishing roller 24 is rotated to replenish the toner from the toner hopper 25 to the developer reservoir 23. The rotation of the toner supply roller 24 may be performed for a predetermined time by using a timer or the like. As a result, the developer pool 23
Since a developer having no color mixture is replenished in the toner, if the toner replenishing roller 24 is connected so as to interlock with the operation of the developer carrying carrier 21, then the development is performed in the same manner as in the conventional multicolor developing device. Be seen.

The multi-development apparatus of the present invention is not limited to the recording apparatus by the electrophotographic method as shown in FIGS. 1 and 3, but can be applied to the recording apparatus by the charging recording method using a multi-stylus electrode or the like. Both a one-component developer and a two-component developer can be used in the multicolor developing device of the present invention. Further, by using a developing device or a means for detecting color mixture on the surface of the image forming body, the toner replenishing device is stopped based on the information,
You may make it drive.

〔The invention's effect〕

In the multi-color developing device of the present invention, when color mixing occurs in the developing device, the user can easily restore the developer to a color-free state without taking out the developing device, and does not require a complicated device. Therefore, there are many effects that the recording apparatus is not enlarged and the cost is not increased.

[Brief description of drawings]

FIGS. 1 and 3 are schematic configuration diagrams showing an example of a multicolor image recording apparatus, and FIGS. 2 and 4 are schematic configuration diagrams showing an example of a developing device of a multicolor developing apparatus. 1 ... Image forming member, 2 ... Multicolor developing device, A to D ... Developing device, 21 ... Developer carrier, 21a ... Developing sleeve, 21b ... Magnet body, 23 ... Developer pool, 24: Toner supply roller, 25: Toner hopper.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-58-111076 (JP, A) JP-A-55-55370 (JP, A) Practical development Sho-55-79343 (JP, U)

Claims (1)

[Claims] 1. An electrostatic latent image forming means is provided around an image forming body which is rotated to form an electrostatic latent image on a surface of the electrostatic latent image forming means. And a charging carrier having the same charge polarity, a developer transport carrier, a developer reservoir for supplying the developer onto the developer transport carrier, a toner hopper for storing the toner, and a toner in the toner hopper are fed to the developer reservoir. In a multicolor developing device of a multicolor image recording apparatus comprising a plurality of developing devices provided with toner replenishing means, the developer transport carrier of each developing device and the operation mechanism of the toner replenishing means are provided to eliminate the toner in the developer pool. A multicolor developing device characterized in that it can be switched between the operation of only the developer transport carrier for the operation and the operation of only the toner replenishing means for accumulating a predetermined amount of toner in the developer pool from which toner has been exhausted. .