JPH02308190A - Color image forming device - Google Patents

Abstract

PURPOSE:To facilitate toner cartridge replacement, to prevent erroneous engagement, to share a die and to reduce costs by integrally providing plural toner cartridges feeding toner to developing units so that they can be attached and detached. CONSTITUTION:The toner cartridges 209a to 209d can be integrally joined by engaging a connecting means 91a with a connecting means 92a and a connecting means 91b with a connecting means 92b; the connecting means 91a and 91b are provided on an upper side wall 91, and the connecting means 92a and 92b on a lower side wall 92. When a flange 211 provided on the toner feed inlet 210 of the toner cartridge 209a, for instance, is pushed by aligning it with a receiving groove 212 provided on the toner feed inlet 208 of the developing unit 32, for instance, all the toner cartridges 209a to 209d turning into one body are properly and readily engaged with the developing units 32 to 35. Consequently, toner cartridge replacement is facilitated, erroneous engagement is prevented, and the toner cartridge sharing is realized to reduce costs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic color image forming apparatus.

[Conventional technology]

Generally, this type of color image forming apparatus includes a photosensitive drum at its center, and a plurality of developing devices containing chargers and toners of different colors located therebelow. These plurality of developing devices are usually arranged on one side of the photosensitive drum in the rotational direction. This is because the transfer portion for the color toner image formed on the drum and the recording paper path are provided on the lower surface of the drum. However, when multiple developing units are installed on the side of the photoreceptor drum, the opening on the developing sleeve side of each developing unit is oriented horizontally, so if toner leaks from that opening, it may leak from the lower stage. There was a risk that the toner could enter through the opening of the developing device and mix toners of different colors.

In order to prevent this, the applicant has provided a transfer section for transferring the color toner image formed on the photoreceptor drum onto recording paper, a fixing section, and a paper discharge path for the recording paper on the upper surface of the drum. A developing device was placed below the photoreceptor drum.

(Problem to be Solved by the Invention) However, in the above case, since the opening on the developing sleeve side faces upward, there is no toner leakage, but the plurality of developing devices are rounded along the photoreceptor drum, and
Since the toner cartridges engaged with this are arranged side by side, if each toner cartridge is independent, there is a risk of confusing the developing device when replacing the entire toner cartridge at the same time. on the other hand,
Changing the shape of the coupling port for each toner cartridge made it impossible to use a common mold, leading to increased costs.

The present invention is intended to solve the above-mentioned problem, and it is an object of the present invention to provide a color image forming apparatus that can be expected to facilitate toner cartridge replacement work, prevent incorrect engagement, and reduce costs by standardizing molds. The purpose is

[Means to solve the problem]

To achieve the above object, the present invention provides a color image forming apparatus equipped with a process cartridge in which a plurality of developing devices are disposed below a photoreceptor, including a plurality of toner cartridges that replenish toner to each of the developing devices. The toner cartridge is integrally and removably provided, and is configured to improve the workability of toner cartridge replacement and to reliably prevent erroneous engagement.

〔Example〕

Next, the present invention will be described based on an embodiment shown in the accompanying drawings.

FIG. 1 shows a color image forming apparatus (printer) according to the present invention. The printer has a clamshell structure divided into an upper housing 1 and a device main body 2. The upper housing 1 can be opened in the six directions of the arrows around the hinge joint portion 1a with the main body 2 of the apparatus.

The image forming section of the printer includes a charger 31 around a photoreceptor drum 30, and developing devices 32, 33, and 3 containing yellow, magenta, cyan, and blank toners, respectively.
4.35 and a cleaning device 36 are disposed and are housed integrally within the process cartridge 3. This process cartridge 3 is inserted into the apparatus main body 2 via a guide member 20.
It is stored in a removable state.

Each of the developing units 32 to 35 is provided below the photosensitive drum 30 with the opening on the developing sleeve side facing upward. This is to prevent the developer from flowing out and falling from the opening of each developing device and mixing into other developing devices.

The printer includes a laser writing unit 4 in a side space inside the process cartridge 3, performs laser scanning on the photosensitive drum 30 diagonally downward, and directs the recording paper conveyance path 5 above the process cartridge 3, that is, above the process cartridge 3. Housing 1
The photosensitive drum 30 is disposed in a portion spanning both the photosensitive drum 30 and the main body 2, and a color toner image formed on the circumferential surface of the photosensitive drum 30 is transferred to the lower surface of the recording paper. Providing the recording paper conveyance path 5 on the upper housing 1 side facilitates jam removal and maintenance work, and since the large and heavy process cartridge 3 is not mounted on the upper housing l, This has the advantage of making opening and closing operations easier.

The process of copying a color toner image by the printer is performed as follows.

That is, when a color signal output from an image reading device (not shown) is input to the radar writing unit 4, a laser beam generated from a semiconductor laser (not shown) is scanned by a polygon mirror 42 rotated by a drive motor 41. is,
The optical path is bent by the mirror 44 through the fθ lens 43, and is projected onto the circumferential surface of the photoreceptor drum 30 to which a charge has been previously applied by the charger 31.

On the other hand, when scanning is started, the laser beam is detected by the index sensor, modulation of the beam by the first color signal is started, and the modulated beam is transferred to the photoreceptor drum 30.
Scan the 0 circumferential surface.

Therefore, the main scanning by the laser beam and the photosensitive drum 30
The first image is formed on the peripheral surface of the drum 30 by the sub-scanning caused by the rotation of the drum.
A latent image is formed corresponding to the color of the image. This latent image is developed by a developing device 32 containing, for example, yellow (Y) toner. The toner image thus obtained passes under the blade 35a of the cleaning device 36, which is separated from the peripheral surface of the photosensitive drum 30 while being held on the drum surface, and enters the next copy cycle.

In the next cycle, the photoreceptor drum 30 is charged again by the charger 31, and the second color signal output from the signal processing section is input to the writing unit 4, and the drum 30 is charged again in the same way as in the case of the first color signal. Writing occurs on the surface and latent scratches are formed. The latent image is developed by a developing device 33 containing, for example, magenta (M) toner. This magenta (
The toner image M) is formed in the presence of an already formed toner image.

The developing device 34 containing cyan (C) toner after the above repetition
However, the developing devices 35 containing black (BK) toner operate one after another, superimposing cyan and black toner images on the drum surface.

A direct current or alternating current bias is applied to the developing sleeves of each of the developing units 32 to 35 to perform shirting development of toner, and the development is applied to the photosensitive drum 30 without contacting it.

The color toner image developed in this way is transferred to the transfer section 60.
At this time, sheets are fed one by one from a paper feed cassette 61 by a paper feed means 62 consisting of a paper feed roller 62a and a separating member 62b, and are transferred all at once onto the bottom side of the recording paper fed through a conveyance guide 63. . The recording paper after transfer is separated by the separation claw 64.
The suction type conveyor belt 6 is separated from the drum circumferential surface by
After being carried into a fixing device 66 via a paper transfer roller 5 and fixed thereon, the paper is discharged onto a tray 68 via a paper discharge roller 67.

The side wall 2# of the apparatus main body 2 can be opened in the direction of arrow B, and the outer guide plate 63a of the conveyance guide 63 can also be opened outward centering on its base end 63a' to prevent recording paper from jamming. We make it easy to process.

As described above, the blade 36a of the cleaning device 236 comes into contact with the photosensitive drum 30 from which the recording paper has been separated from the drum circumferential surface to remove residual toner.

After removing the toner, the blade 36a separates from the drum surface again. This starts a new color image forming process.

The toner removed from the drum surface is collected in the lower chamber 36b, carried out by a screw 69 from the chamber 36b, and collected in the waste toner box 70 via a toner conveying path (indicated by a dotted line) 69'. In the illustrated example, the waste toner box 70 is connected to the cleaning device 36 with the drum 30 in between.
Although it is provided on the opposite side, it may be provided on the same side if the space is to be punched.

Each of the developing units 32 to 35 accommodates a developer of a specific color, but since they have the same structure and function, FIGS. 2 to 4 are illustrated using the developing unit 33 as a representative example. Refer to and explain.

In FIG. 2, 201 is a housing, 202 is a developing sleeve, and 203 is a thin layer forming member that regulates the amount of developer. The thin layer forming member 203 is pressed against the developing sleeve 202 with a constant load without the presence of developer. Reference numerals 204 and 205 indicate first and second stirring members having a screw structure that transport the toner in opposite directions, and 206 indicates a scraper.

Thus, the developer in the housing 201 is conveyed to the back side of the figure by the thrust of the second stirring member 205, and
It moves to the 4th side and is transported to the front side by the thrust. During this time, the toner and carrier are well mixed and become a triboelectrically charged homogeneous developer, which is deposited in a layer on the circumferential surface of the developing sleeve 202 .

The developer attached to the developing sleeve 202 is made into a thin layer by a thin layer forming member 203, and the latent image on the photosensitive drum 30 is developed without contact. In this non-contact development, a developing bias including an AC component is applied to the developing sleeve 202 from a power supply (not shown), so that only the toner in the developer is selectively transferred to the latent image surface on the drum 30. The toner component is consumed by this development, and the developer with a high carrier ratio is peeled off from the developing sleeve 202 by the scraper 206.
The toner is again mixed with the developer in the housing 201 having a high toner ratio.

FIG. 3 is a partial sectional view of the toner supply chamber 20 extending from the housing 201, as seen from the direction of the arrow X in FIG.
7 is shown. A toner replenishment port 208 is provided on the upper surface of the toner replenishment chamber 207 . This toner supply port 2
08 is provided with a groove 212 in which a flange 211 provided on the outer periphery of the toner inlet 210 of the toner cartridge 209 can be slidably engaged in the horizontal direction.

213 is a shutter that closes the toner supply port 208;
The shutter 213 opens in conjunction with the engagement of the toner cartridge 209. That is, the shutter lid 213 is normally closed by the action of a spring (not shown), and when the flange 211 of the toner cartridge 209 is slidably engaged with the groove 212 in the horizontal direction, the bottle provided on the bottom surface of the cartridge 209 is closed. 214 can press a protruding piece 215 protruding from the upper surface of the shutter 213 in the opening direction. 208' is a pin passage groove.

Reference numeral 216 denotes a replenishment roller provided in the toner cartridge 209. The replenishment roller 216 is driven and stopped by a signal from a toner density sensor (not shown) provided at an appropriate location within the developing unit via a gear 217 at the end of its shaft. It is connected to a drive motor that However, when the supply roller 216 rotates,
The toner stored in the toner cartridge 209 falls from the aperture 21B and is replenished into the toner supply chamber 207. The thus replenished toner is fed into the housing 201 by the second stirring member 205 and mixed with the existing developer.

Figure 5 shows a developing device 32°33.34.3 containing yellow, magenta, cyan, and black toner, respectively.
5, and toner cartridges 209a and 2 containing toner of the corresponding color engaged with the toner supply lower 08 of each developing device.
09b, 209c.

209d is shown in an engaged state. These toner cartridges 209a to 209d can be integrally engaged with and detached from the developing devices 32 to 35. That is, the individual toner cartridges 209a to 209d may be inseparably connected to each other between adjacent walls, or may be separably connected to each other. In the latter case, the specific structure of the coupling means can be arbitrarily determined, but in the illustrated example, the side walls 91 and 92 of the toner cartridges 209a to 209d are used.
Coupling means 91a and 92a, 9 that engage with each other at the upper and lower parts of the
1b and 92b are provided.

The upper coupling means 91a is formed by providing a dovetail groove M in a horizontally continuous flat raised part H, as shown in FIG. They can be connected to each other by forming an L-shaped protrusion T and sliding it horizontally. Further, the lower coupling means 91b and 92b are formed by opposing protrusions T and T' having an L-shaped cross section that engage with each other in the vertical direction, as shown in FIG. 6(B).

In the embodiment described above, the toner cartridges 209a to 209d containing yellow, magenta, cyan, and black toners respectively engage coupling means 91a and 92a, and 91b and 92b provided at the upper and lower portions of the side walls 91.92. are integrally connected. The combined toner cartridges 209a to 209d have a flange 211 provided at the toner inlet 210 of one toner cartridge (for example, 209a), and a flange 211 provided at the toner supply port 208 of one developing device (for example, 32). Groove 2
12, all the toner cartridges 209a to 209d can be simultaneously and easily inserted into the developing device 32.
~35 will be properly engaged.

Therefore, the toner cartridges 209a to 209d that are engaged with the developing device can be easily removed by holding the entire assembly and pulling it toward you.

In the above embodiment, the toner replenishment chambers 20 of the developing devices 32 to 35 are arranged in a round shape below the photoreceptor drum 30.
The toner replenishment ports 208 of the developing units 32 to 35 are formed at the same level, and all the toner cartridges 209a to 209d are integrated in a horizontal manner at the same level. All the toner cartridges 209a to 209d may also be integrated with round steps.

〔Effect of the invention〕

As described above, the present invention provides a color image forming apparatus equipped with a process cartridge in which a plurality of developing devices are disposed below a photoreceptor, in which a plurality of toner cartridges that supply toner to each of the developing devices are integrated. Since the toner cartridge is detachably provided, a plurality of toner cartridges can be connected and detached from a plurality of developing units at the same time, improving the workability of replacing the toner cartridges. Furthermore, since the toner cartridges that are integrally engaged and detached do not get out of order, there is no possibility of incorrect attachment.

Furthermore, since toner cartridges can be shared, manufacturing costs can be reduced, and various other excellent effects can be achieved.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, in which FIG. 1 is a schematic sectional view of a printer, FIG. 2 is a sectional view of a developing device, and FIG. 3 is a partial sectional view seen from the X direction in FIG. 2. FIG. 4 is a partially cutaway perspective view showing the toner cartridge engaged with the toner supply port of the developing device, FIG. 5 is a partially cutaway front view showing the relationship between the developing device and the toner cartridge, and FIG. 6(A) , (B) is an enlarged sectional view of the coupling means. ■--Upper housing 2-Device main body 3--Procell cartridge 30-Photosensitive drums 32, 33, 34, 35--Developer 201--Developer housing 202--Developing sleeve 203-Thin Layer forming member 204.205-first and second stirring member 207-h toner supply chamber 208--toner supply port 209a to 209d-) toner cartridge 210
--Toner inlet 211--Flange 213--Shutter 214--Bin 215--Protrusion 216--Replenishment roller 217--Gear 218--Aperture openings 91, 92--) of the toner cartridge Both side walls 91a
, 92a, 91b, 92b - Application for permission when connecting means
People Konica Co., Ltd. Figure 2 Figure 4 Figure 5r! A ((A) (B)

Claims (1)

[Claims] In a color image forming apparatus equipped with a process cartridge in which a plurality of developing devices are arranged below a photoreceptor, a plurality of toner cartridges for replenishing toner to each of the developing devices are integrally and detachably provided. A color image forming device characterized by: