JPH0764381A - Color image forming device - Google Patents

Abstract

PURPOSE:To provide a color image forming device which efficiently operates even when used for a monochrome image or for a color image, requires minimum frequency and labor in the replacement of a color developing device and the replenishment of toner, maintains a color balance at all times, and is easy to handle and economical. CONSTITUTION:The color image forming device is provided with Y, M, C and Black developing devices arranged in an adjacent relation, parallel to an image forming body. In the color image forming device, a black developing unit 2004 is constituted by being integrated with the black developing device 204 into which a toner hopper storing black toner is incorporated. Alternatively, a process cartridge 2101 is constituted by uniting the black developing unit 2004 and the image carrier, the Y, M and C developing devices are also integrated to constitute a color developing unit, and the replenishment of the toner hopper with the black toner is carried out by separating the color developing unit from the black developing unit 2004 or the cartridge, or it is carried out as it is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus using a photoconductor drum or a photoconductor belt for forming a toner image on its surface, and in particular, a black toner image and an optional developing device for color are mounted. The present invention relates to a color image forming apparatus capable of recording a color image as well.

[0002]

2. Description of the Related Art An image recording apparatus using a photoconductor drum or a photoconductor belt has a plurality of developing devices arranged on the photoconductor drum or the photoconductor belt. Is suitable for recording color images that require a large number of developing devices because it is easy to arrange each developing device in almost the same state, and yellow, magenta, cyan, and black toners are used as the developer, respectively. It is also known that the four developing devices used in the above can be arranged to record a black toner image and a color image. In such a conventional color image forming apparatus, the four developing devices can be attached and detached together with the photosensitive drum or the photosensitive belt so that the four developing devices can be easily replaced and toner can be replenished to them. Or, it may be detachably attached to the image forming apparatus separately from the photoconductor drum or the photoconductor belt, and when recording only the black toner image, the developing device other than the black toner is completely redundant. There is a problem that it tends to be wasteful as it was said that in order to replenish only the black toner that is frequently used, other developing devices must be removed and replaced together. .

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a developing device for each of Y, M, and C developers for color images can be optionally added. When recording a color image, the arrangement of the developing device for the color image can be easily done by mounting the replaceable Y, M and C developing device units, and the replenishment of toner to each developing device can be replaced. The present invention aims to provide an image forming apparatus using a photoconductor drum or a photoconductor belt, which can perform independently a black-and-white image developing device and a color image developing device by taking out the process cartridge or the developing device unit. To do.

That is, according to the present invention, the developing device of the color image forming apparatus can be separated into a monochrome image forming apparatus and a color developing apparatus, and can be used as a monochrome image forming apparatus while they are separated. It can also be operated as an image forming device, and depending on the frequency of operation for black and white and the frequency of operation for color, toner replenishment and updating of the developing device can be performed easily and reliably and with high image quality. An object is to provide a good color image forming apparatus.

[0005]

[Means for Solving the Problems]
This is achieved by the configuration of any one of the technical means in (7).

(1) Y arranged in parallel with the image forming body,
In a color image forming apparatus having M, C, and black developing devices, a process cartridge is formed by integrating an image forming body and a black developing device in which a toner hopper containing black toner is incorporated into a process cartridge. , C are also integrated into a unit, the cartridge and the unit are detachable, and the black toner is replenished to the toner hopper, the unit is separated from the image forming body of the cartridge. A color image forming apparatus characterized by being performed.

(2) The color image forming apparatus according to item (1), wherein the separation is performed such that the process cartridge moves with respect to the unit.

(3) The color image forming apparatus according to item (1), wherein the separation is performed so that the unit moves with respect to the process cartridge.

(4) Y arranged in parallel with the image forming body,
In a color image forming apparatus having M, C and black developing devices, the Y, M and C developing devices are integrally provided as a detachable and replaceable unit, and toner is supplied to the black developing device. A color image forming apparatus, characterized in that a toner hopper for performing is provided, and the toner hopper is provided adjacent to the cleaning section.

(5) The color image forming apparatus according to item (4), wherein the detaching and replacing direction of the unit is the same as the drawing direction of the toner hopper for supplying the black toner.

(6) Y arranged in parallel with the image forming body,
In a color image forming apparatus having M, C, and black developing devices, a black toner hopper for the black developing device is provided adjacent to the cleaning unit, and Y, M, and C are provided above the Y, M, and C developing devices. 2. A color image forming apparatus, wherein each toner hopper is provided and an integrated unit is provided separably.

(7) A color image forming apparatus as described in (6), wherein the black toner hopper, the image forming body and the black developing device are integrated to form a process cartridge.

[0013]

That is, in the image forming apparatus of the present invention, the process cartridge in which the black toner developing device is mounted on the image forming body and the unit of Y, M, and C developing devices for color image are exchanged. Since it is designed to be mounted on the image forming apparatus as much as possible, when recording only the black toner image, it is not necessary to mount the process cartridge and the unit of the color developing device. Can be done by attaching / detaching only the process cartridge, such as replacing the process cartridge, replacing the developing device of the process cartridge, or replenishing toner to the developing device of the process cartridge. To supply toner for color images to
The replacement of the color developing device unit or the replenishment of toner to each developing device of the unit can be performed by attaching and detaching the Y, M, and C three developing device units for color.

Also, from the top of the main body structure, the larger process cartridge is first fixed to the main body in a couple with the drive system and then fixed, and then the developing unit is attached and detached securely. to enable. Further, it is possible to adopt a structure in which the developing device unit abuts against a part of the process cartridge, and in particular, it is possible to guarantee the maintenance of the gap between the photoconductor and the developing sleeve in the developing device unit.

Further, the color developing device unit can always constitute an image forming apparatus together with a process cartridge having a black toner hopper and a developing device incorporated therein.
The Y, M, and C developing units for the color are used about the same number of times as the unit of the black developing unit, and when it reaches the end of its life, it can be removed from the process cartridge and replaced with a new one. It is also possible to easily and easily replenish each color toner in the middle.

However, the color image forming apparatus of this combination is convenient when it is almost used for a color image, but when it is almost used only as a black and white image forming apparatus, a Y for color image is used. , M, C developing devices are always installed, so it is not a good idea.

[0017]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a color image forming apparatus of the present invention.

In the figure, reference numeral 100 designates a photosensitive drum which is an image forming body, which is formed by coating an OPC photosensitive body on the drum and is grounded and driven and rotated clockwise. Reference numeral 112 denotes a charger, which is disposed on the peripheral surface of the photoconductor drum 100. Prior to the charging by the charger 112, exposure by PCL using a light emitting diode or the like is performed to eliminate the history of the photoconductor until the previous printing. The peripheral surface of the photoconductor is neutralized.

Image exposure means 113 after uniform charging of the photoreceptor
Thus, image exposure is performed based on the image signal. The image exposure means 113 is a means for scanning the polygon mirror 1131 which rotates using a laser diode (not shown) as a light emitting source, an optical path bent by a reflection mirror 1132 through an fθ lens and the like.
A latent image is formed by rotation (sub-scanning) of the photosensitive drum 100. In this embodiment, the image area is exposed to form an inverted latent image.

Developers 201, 202, 203 each having a built-in developer composed of toner such as yellow (Y), magenta (M), cyan (C), and black (K) and a carrier around the periphery of the photosensitive drum 100. , 204 are provided, and first, 1
Color development is performed by the developing sleeve 206 which has a magnet built therein and holds the developer and rotates. The developer consists of a carrier in which ferrite is used as a core and is coated with an insulating resin around it, and a toner whose main component is polyester and pigments according to the color and charge control agents, silica, titanium oxide, etc. are added. The agent regulates the layer thickness on the developing sleeve 206 by the cutting edge regulating plate and is conveyed to the developing area.

The gap between the developing sleeve 206 and the photosensitive drum 100 in the developing area is a gap D _SD larger than the layer thickness (developer), and a bias is applied between them. Since the bias and the toner are both charged with the same polarity, visualization (reversal development) is performed by the toner which is given a chance to be separated from the carrier by this bias voltage.

After the visualization of the first color is completed, the process proceeds to the image forming process of the second color, the uniform charging is performed again by the scorotron charger 112, and the latent image based on the image data of the second color is formed by the image exposing means 113. To be done. At this time, the charge elimination by PCL performed in the image forming process for the first color is not performed because the toner adhering to the image portion for the first color scatters due to the sudden decrease in the potential around the image.

A latent image similar to that of the first color is formed and developed on the portion of the photoconductor having a high potential all over the peripheral surface of the photoconductor drum 100 without the image of the first color. However, in the area where the first color image is developed again, a latent image is formed by the toner attached to the first color and the latent image is formed by the electric charge of the toner itself, and the development is performed according to the potential difference of the bias. .

An image forming process similar to that of the second color is performed for the third and fourth colors, and a visible image of four colors is formed on the peripheral surface of the photosensitive drum 100.

On the other hand, the recording paper P fed from the paper feed cassette 121 by the paper feed mechanism 122 is fed to the transfer area by the transfer belt device 130 in which the transfer belt 131 is stretched, and the circumference of the photoconductor drum 100. The multicolor image on the surface is collectively transferred onto the recording paper P.

The transfer belt 131 has a thickness of 10 ⁶ to 10 ¹⁴ Ω · cm resistance formed by forming an outer FLC layer on a urethane rubber base.
An endless rubber belt of 0.4 to 1.0 mm. The transfer belt 131 is stretched between holding rollers 132 and 133. The recording paper P enters a nip portion (transfer area) formed by the photoconductor drum 100 and the transfer belt 131, and a transfer electric field is applied from the back surface of the transfer belt 131 by the corona discharger 136, so that the recording paper P is multicolored. The image is transferred.

Recording paper P separated from the photosensitive drum 100
The transfer belt 131 is subjected to neutralization by AC corona discharge with the shaft of the holding roller 133 on the downstream side, which stretches the transfer belt 131, as a counter electrode, or while receiving the AC corona discharge.
Separate from 131. The transfer belt of this transfer belt device 130
131 is a shaft 133a of the holding roller 133 on the downstream side during the formation of the multicolor image.
Is separated from the photosensitive drum 100 with the center of rotation as the center of rotation.

The recording paper P holding the multicolor image separated from the transfer belt device 130 is conveyed to a fixing device 123 composed of two pressure bonding rollers having a heater inside at least one of the rollers, and is transferred between the pressure bonding rollers. The applied toner is melted by applying heat and pressure, fixed on the recording paper P, and then discharged to the outside of the apparatus.

After the transfer, the residual toner remaining on the peripheral surface of the photosensitive drum 100 is subjected to static elimination by a static eliminator using an AC corona discharger, and is then removed from the rubber material which is in contact with the cleaning device 116 or the photosensitive body. Consists of cleaning blade 116
It is scraped off into the cleaning device 116 by a and discharged or stored by a screw or the like.

The photoconductor drum 100 from which the residual toner has been removed by the cleaning device 116 is exposed by PCL and then uniformly charged by the scorotron charger 112, and enters the next image forming cycle. During the formation of the multicolor image, the cleaning blade 116a is separated from the surface of the photoconductor,
AC static elimination by the static eliminator is kept in the OFF state.

The above description is for the case where the image forming body is the photosensitive drum 100, but the same applies to the case where the belt photosensitive body 101 shown in the side views of FIGS. 14 and 15 is used as the image forming body. A good image is formed by the above process.

Next, an embodiment based on each claim of the present invention will be specifically described with reference to the drawings.

The embodiment of claim 1 is the same as the color image forming apparatus having the general function of forming a color image as shown in FIG.
2, the photoconductor drum 100, the cleaning device 116, the charger 112, and the black developing device 204 incorporating the black toner supply port 204S are integrated to form the side view of FIG. 2 and the perspective view of FIG. As shown in the drawing, a process cartridge 2101 and a color developing device unit 2004 incorporating Y, M, and C color developing devices 201, 202, and 203 are shown in the perspective view of FIG. The objects are those that can be separated from each other.

In the embodiment of claim 2, the separating operation is as shown in FIG.
The process cartridge 2101 is configured to move with respect to the color developing unit as shown in the perspective view of FIG. 1, and the toner can be replenished from the toner replenishing port 204S of the black developing device 204 while being separated from the machine. There is.

In the third embodiment, as shown in the perspective view of FIG. 9, the process cartridge 2101 is fixed in the opposite direction, and the color developing device unit 2004 is moved and removed therefrom. is there.

This also allows the process cartridge 21
Since 01 and the color developing unit 2004 can be separated from each other, the color developing unit can be installed in the main body of the image forming apparatus.
After removing from the black toner hopper 204H, the window 11 on the ceiling of the main body 10 is opened as shown in the perspective view of FIG.
The black toner can be easily replenished toward the replenishment port 204S.

Further, as shown in the perspective view of FIG. 6, each color Y, M, C developing unit 201, 202, 203 is not provided with a toner replenishing port, and a color developing unit unit 2004 is constituted to configure each color toner unit. When the consumption is completed, each developing unit is considered to have reached the end of its life and the entire unit is replaced.

In the process cartridge 2101, the photosensitive drum 100, the charging device 112 and the cleaning device 116 are incorporated together with the black developing device 204, but the cleaning device 116 and the charging device 112 are excluded to form the process cartridge. It is also possible. In that case, the cleaning device 116 and the charger 112 are independently attached to the main body 10.

As described above, the embodiments of claims 1, 2 and 3 can be similarly applied to the two-part photosensitive drum type image forming apparatus shown in FIGS. 14 and 15
It can also be applied to the belt-photosensitive image forming apparatus shown in FIG.

The embodiment of claim 4 is the image forming apparatus shown in the side view of FIG.
A black toner hopper 204H disposed above the cleaning device 116 and a black developing device 204 disposed below the color developing device on the opposite side of the cleaning device 116 sandwiching the photosensitive drum 100 are provided. There is. The black toner hopper 204H and the black developing device 204 are connected by, for example, a flexible screw pipe 204P shown by a dotted line in the figure.

With this structure, all the toner supply ports can be provided above. By pulling out the cartridge or opening the optical system 113 upward, there is an advantage that each toner can be replenished from the same direction. This structure can be commonly used in claims 5 to 7 described later.

Further, the Y, M and C developing units 201, 202 and 20
Although the color developing device unit 2004 is integrally provided with 3, the color developing device unit 2001 or 2003 can be configured by further providing a toner replenishing port therein.

In FIG. 10, instead of the unit 2004, a unit 2001 having a replenishment port for each toner and a toner hopper is mounted, but of course, the unit of 2004 as described above may be mounted.

Further, it can be used as a black and white image forming apparatus with the color developing device unit 2004, 2001 or 2003 removed except when forming a color image, and it can be used as a color image forming device in a color developing device. A new color developer unit 2004 when it reaches the end of its useful life
The color toner can be replenished in the middle of a 2001 or 2003 type developing unit.

In the fifth embodiment of the present invention, both the detaching and replacing direction of the unit 2001 and the pulling-out direction of the process cartridge 2102 having the toner hopper 204H for black toner replenishment are set to be the same as the axial direction of the photosensitive drum 100. I made it easy. Of course, when used for black, the color developing unit 2001 or 2004 may be removed or loaded. Further, the photosensitive drum 100 may be detachable in a direction perpendicular to the axis thereof.

As described above, the embodiments for claims 4 and 5 are as follows.
The same can be applied to the two-part photosensitive drum type image forming apparatus shown in FIGS. Further, it is also applied to the belt photosensitive member image forming apparatus shown in FIGS. In that case, the process cartridges become 2105 and 2106, respectively.

In the sixth embodiment, the black toner hopper 20 is provided adjacent to the cleaner portion as shown in the side view of FIG.
4H is provided, and further, for example, a black developing device 204 connected by a screw pipe 204P is provided, and the color developing device unit has hoppers 201H, 202 for each toner in each developing device.
A unit 2001 or 2003 in which H and 203H are incorporated is mounted so that the black developing unit and the unit can be separated.

As a result, the toners for the Y, M, and C colors and the black toner differ depending on the usage state of the image forming apparatus, but it is advantageous because the toner replenishment can be handled efficiently according to the frequency. Replenishment of each toner can be performed from the top of the main body 10 in a state where the toner is constantly attached to the main body 10 or by pulling out the black developing device unit and the color developing unit from the main body 10.

As shown in FIG. 10, the embodiment of claim 7 is the same as the embodiment of claim 6, in which the black toner hopper 204H, the photosensitive drum 100 as an image forming body and the black developing device 204 are integrated. This is a process cartridge 2102 as shown in the side view of FIG. And, it can be separated from the color developing unit.

As described above, the embodiments for claims 6 and 7 are as follows.
The same can be applied to the two-part photosensitive drum type image forming apparatus shown in FIGS. Further, the invention is also applied to the belt-photosensitive image forming apparatus shown in FIGS. In that case, the process cartridges are 2105 and 2106, respectively.
become that way.

[0052]

In the color image forming apparatus, the image forming body (photoreceptor), the black developing device and the toner hopper are used as the bases,
Depending on the case, Y, M, C for process cartridge and color including peripheral functions such as charger, cleaner, and static eliminator
Each developing unit is integrated into one unit, and the one in which the toner hopper is also combined is made into one unit, and the other one is attached to the main body and divided into three blocks. By making the block of the cartridge and the block of the unit detachable, when the color image forming apparatus is mainly used in black and white, the color developing unit is removed, and the unit is attached only when necessary. It becomes possible to form a color image.

For this reason, when it is used for black and white and there is a demand to use it for color, it is necessary to purchase a color developing unit as an option and transform it into a color image forming apparatus at that time. Will also be possible.

Since the Y, M, and C developing units are integrated into one unit, the life of this unit is reached.
Alternatively, it has become possible to minimize the number of times of toner supply and the number of times of unit replacement without wasting the toner while maintaining the color balance until the time to replace the inside toner comes.

When the black is frequently used, it is necessary to replace it because the black cartridge is consumed greatly and the replacement of Y, M and C is low. This can be reused even more. On the other hand, in the conventional one in which the color and black developing devices are completely integrated, when the life of the black developing device is reached, the expensive and still usable color developing device is also discarded, so it is completely useless. Become. The present invention solves this problem altogether.

This allows the color image forming apparatus to be provided with an effective utilization method that matches the circumstances of each field of use. That is, in the business field, black print is often used, and in the graphic field, a large amount of color is used. However, if the color image forming apparatus of the present invention is organized, either request can be met without any resistance. .

Further, it is easy to prevent interference when the cartridge is attached and detached.

Further, the toner hopper can be integrated with each cartridge, which is convenient.

Since the black cartridge can be attached and detached without completely attaching and detaching the Y, M, and C color developing units, the operation of only replenishing the black toner is further simplified.

Further, the interference prevention mechanism between the cartridge and the unit can be made simple and reliable.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention.

FIG. 2 is a side view of an embodiment of a process cartridge and a color developing unit according to the present invention.

FIG. 3 is a perspective view of an embodiment of the process cartridge of the present invention.

FIG. 4 is a perspective view of an embodiment of a color developing unit according to the present invention.

FIG. 5 is a perspective view of an embodiment of a color developing device unit of the present invention.

FIG. 6 is a perspective view of an embodiment of a color developing unit of the present invention.

FIG. 7 is a side view of an embodiment of the present invention.

FIG. 8 is a perspective view of an embodiment of the present invention.

FIG. 9 is a perspective view of an embodiment of the present invention.

FIG. 10 is a side view of an embodiment of the present invention.

FIG. 11 is a side view of an embodiment of a process cartridge and a color developing unit according to the present invention.

FIG. 12 is a side view of a two-divided type embodiment.

FIG. 13 is a side view of a two-divided type embodiment.

FIG. 14 is a side view of a color image forming apparatus incorporating a process cartridge using a belt photosensitive member and a color developing device unit.

FIG. 15 is a side view of a color image forming apparatus in which a process cartridge using a belt photosensitive member and a color developing device unit are incorporated.

[Explanation of symbols]

10 Main body 11, 12 Ceiling window 15 Groove 100 Photoconductor drum 101 Belt photoconductor 103 Bar 104 Light-shielding curtain 105 Rotating disc 106 Fixed pin 107 Spring 112 Charger 116 Cleaning device 136 Corona discharger 201, 202, 203, 204 Y, M, C, black developing units 201H, 202H, 203H, 204H Y, M, C, black toner hoppers 201S, 202S, 203S, 204S Y, M, C, black toner supplying ports 204P screw pipe 2001, 2003, 2004 Color developing unit 2101 Process cartridge

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Claims (7)

[Claims] 1. A Y, M, arranged adjacently in parallel with an image forming body.
In a color image forming apparatus having C and black developing devices, an image forming body and a black developing device in which a toner hopper for accommodating black toner is incorporated are integrated to form a process cartridge. Each developing device is also integrated to form a unit, the cartridge and the unit are detachable, and black toner is supplied to the toner hopper by separating the unit from the image forming body of the cartridge. A color image forming apparatus characterized by being performed. 2. The color image forming apparatus according to claim 1, wherein the separation is performed such that the process cartridge moves with respect to the unit. 3. The color image forming apparatus according to claim 1, wherein the separation is performed so that the unit moves with respect to the process cartridge. 4. Y, M, which are arranged adjacent to each other in parallel with the image forming body.
In a color image forming apparatus having C and black developing devices, the Y, M and C developing devices are integrally provided as a detachable and replaceable unit, and toner for supplying toner to the black developing device is provided. A color image forming apparatus, wherein a hopper is provided, and the toner hopper is provided adjacent to the cleaning unit. 5. The color image forming apparatus according to claim 4, wherein the detaching and replacing direction of the unit is the same as the drawing direction of the toner hopper for supplying the black toner. 6. Y, M, which are arranged adjacent to each other in parallel with the image forming body.
In a color image forming apparatus having C and black developing units, a black toner hopper for the black developing unit is provided adjacent to the cleaning unit, and Y, M, and C developing units are provided above the Y, M, and C developing units, respectively. A color image forming apparatus comprising a toner hopper and an integrated unit that is separable. 7. The color image forming apparatus according to claim 6, wherein the black toner hopper, the image forming body, and the black developing device are integrated to form a process cartridge.