JPH04240869A - Color electrophotographic device - Google Patents

Abstract

PURPOSE:To prevent wasteful exchange of color toner for a user with a large need for monochromatic printing by attaching a developing device for black freely attachable/detachable to a processing cartridge. CONSTITUTION:The processing cartridge 2 is installed to be freely attachable to the device main body, and this processing cartridge 2 can be exchanged as a whole. Furthermore, the developer for black 11 is installed to the processing cartridge 2 to be freely attachable, and this can be exchanged independently from developing devices for other colors 5, 7 and 9. Thus, the cost per page for monochromatic printing can be kept down in comparison to the color printing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic process used in an image forming apparatus, and more particularly to replacing a developing device in a color electrophotographic apparatus having a plurality of developing devices.

0002

2. Description of the Related Art In an image forming apparatus using an electrophotographic process, the idea of making the image forming section centering on a photoreceptor into an integrated unit and replacing consumable parts all at once makes the apparatus easier to handle. Since consumables can be replaced even by general users without specialized knowledge, they have become mainstream in recent compact electronic photography. Japanese Patent Publication No. 58-54392 discloses that the method of replacing the photoreceptor, developer, charger, and cleaner all at once as an integrated process cartridge requires complicated adjustment work between the components of an electrophotographic device and maintenance. , discloses content that simplifies repair and replacement work. On the other hand, as disclosed in Japanese Unexamined Patent Publication No. 1-116658, a conventional technology related to color electrophotography includes a plurality of photoreceptors and forms a monochromatic toner image on each photoreceptor. There is a method of overlapping colors when transferring to paper. Furthermore, as disclosed in Japanese Unexamined Patent Publication No. 1-133072, a method is known in which latent images are formed four times on one photoreceptor and development is repeated to perform color overlapping.

0003

[Problems to be Solved by the Invention] The conventional electrophotographic process cartridge described above is a monochrome type that has only one developing device, and when applied to color electrophotography, the cartridge and the entire device become too large. , the usage frequency of each color toner is different, especially the usage frequency of the three color toners of yellow, magenta, and cyan, and the usage frequency of black toner. In general, the frequency of use of color printing is higher than the frequency of use of only black. According to the data investigated so far and calculations based on experiments, it has been found that the amount of black toner used is 2 to 5 times that of toner of other colors. Moreover, since there are large differences between users, it is not sufficient to simply increase the toner capacity. Therefore, when replacing the cartridge, unused toner of colors other than black is often wasted. Furthermore, if cartridges for each color are separated, the number of replacement parts increases, which is inconvenient for the user. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a color electrophotographic apparatus that uses toner efficiently and allows easy toner replacement.

0004

[Means for Solving the Problems] In order to achieve this object, a color electrophotographic apparatus according to the present invention includes: a photoreceptor having photoconductivity; a charger that applies an electric charge to the photoreceptor;
a plurality of developing devices that develop the electrostatic latent image formed by the exposure means; a cleaner that removes toner remaining on the photoreceptor after transferring the toner image to a recording medium; these photoreceptors; a charger; A process cartridge that accommodates a plurality of developing devices and a cleaner, and a process cartridge support member to which the process cartridges are detachably attached are provided, and toner is integrated into a container that accommodates a black developing device among the plurality of developing devices. The storage container is detachably attached to the process cartridge.

[0005]

[Operation] In the color electrophotographic apparatus according to the present invention,
A container that houses the black developer and integrally stores the toner can be attached and removed from the process cartridge that houses the photoconductor, multiple developers, and cleaner, and is used for the frequently used black developer. The container and its toner can be replaced independently.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the drawings. FIG. 1 is a side sectional view of a process cartridge of a color electrophotographic apparatus according to the present invention, FIG. 2 is a side sectional view showing the operation of removing a black developing device from the process cartridge in the color electrophotographic apparatus according to the present invention, and FIG. FIG. 3 is a side sectional view showing the operation of removing the process cartridge from the color electrophotographic apparatus according to the present invention. In these figures,
Reference numeral 3 denotes a photoreceptor, which rotates clockwise in the figure and is charged by a charger 4. 5 is a yellow developer which stores yellow toner 6, 7 is a magenta developer which stores magenta toner 8, 9 is a cyan developer which stores cyan toner 10, and 11 is a black developer which stores black toner 12. A cleaner 13 collects toner remaining without being completely transferred to the photoreceptor 3. These photoreceptor 3, charger 4, each developing device 5, 7, 9
, 11 and the cleaner 13 are housed in a support member 15 to constitute a process cartridge 2. and,
A feature of the present invention is that only the black developing device 11 is independently detachable from the process cartridge 2. Further, the rear end portion of the black developing device 11 protrudes from the support member 15. The process cartridge 2 is
It is detachably attached to the process cartridge support member 20. The process cartridge 20 is an upper structure 2
2, and as the device upper structure 22 opens and closes, it opens and closes integrally with the device upper structure 22 up to a certain opening/closing angle α, and when the opening angle of the device upper structure 22 exceeds α. Once over, the process cartridge 20 is separated from the apparatus upper structure 22 and maintains the state at the opening angle α. Reference numeral 23 denotes a device lower structure, which together with the device structure 23 constitutes a case of the device.

The operation will be explained below. A photoreceptor 3 rotating clockwise is charged by a charged member 4, and an electrostatic latent image for yellow toner development is formed using a laser beam or the like. The electrostatic latent image is developed by a yellow developer 5. Such processes of charging and developing are repeated a number of times corresponding to the color necessary for printing among each color. After the development of all the colors to be printed is completed, the images are transferred onto a recording medium by a transfer charger (not shown). Toner remaining on the photoreceptor 3 without being completely transferred is collected by a cleaner 13. Note that recovery by the cleaner 13 is performed only after the transfer, and cleaning of the toner on the photoreceptor 3 before transfer is not performed. When it becomes necessary to replace the black developing device 11 after continuing such charging and developing processes for a certain period of time, as shown in FIG. Also, the angle α is opened and the black developing device 11 is replaced. In addition, when replacing the process cartridge 2, by opening the upper structure 22 of the apparatus to an angle α or more as shown in FIG. 3, only the upper structure 22 of the apparatus opens, and the process cartridge 2 is
The process cartridge 2 will remain in its original state.
from the process cartridge support member 20,
Exchange.

[0008]

As described in detail above, according to the color electrophotographic apparatus according to the present invention, the black developing device is detachable from the process cartridge. There is no need to wastefully replace toner, and consumables can be replaced efficiently. Furthermore, the cost per page of monochrome printing can be kept lower than that of color printing. Further, since the only replacement parts are a process cartridge containing a color developer and a black developer, the minimum number of replacement parts is required, which makes handling easier for the user.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a process cartridge of a color electrophotographic apparatus according to the present invention.

FIG. 2 is a side sectional view showing the operation of removing a black developing device in the color electrophotographic apparatus according to the present invention.

FIG. 3 is a side cross-sectional view showing an operation for removing a process cartridge in the color electrophotographic apparatus according to the present invention.

[Explanation of symbols] 2 Process cartridge 3 Photoreceptor 4 Charger 11 Black developer 20 Process cartridge support member

Claims (1)

[Claims] 1. A photoreceptor having photoconductivity, a charger for applying an electric charge to the photoreceptor, a plurality of developing devices for developing an electrostatic latent image formed by an exposure means, and a toner image on a recording medium. a cleaner for removing toner remaining on the photoreceptor after the toner has been transferred to the photoreceptor; a process cartridge for housing the photoreceptor, a charger, a plurality of developing devices, and the cleaner; and a process in which the process cartridge is detachably attached. In a color electrophotographic apparatus equipped with a cartridge support member, toner is integrally stored in a container for storing a black developing device among the plurality of developing devices, and this storage container is detachably attached to the process cartridge. A color electrophotographic device characterized by: