JP2001331007A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which can be miniaturized. SOLUTION: A copying machine 1 is equipped with a photoreceptor belt 3 carrying toner images of plural kinds of color toner supplied from a developing device 9, an intermediate transfer body 5 to which the toner image on the belt 3 is transferred, a transfer roller 17 transferring the toner image to paper P from the transfer body 5, and a cleaning device 13 removing and recovering waste toner on the belt 3. In the machine 1, the waste toner on the transfer body 5 after transfer is electrified to have a reverse polarity to the potential by electrification of the belt 3, whereby the waste toner on the transfer body 5 is transferred to the belt 3 and the waste toner transferred to the belt 3 is recovered by the device 13. The device 13 is equipped with a waste toner bottle for black 27 recovering black waste toner and a waste toner bottle for an unspecified color 39 recovering the unspecified color waste toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a laser beam printer, and a facsimile.

[0002]

2. Description of the Related Art In an electrophotographic color image forming apparatus, a toner image of a plurality of colors is formed on an intermediate transfer body by transferring a toner image one color at a time from a photoconductor to an intermediate transfer body. There is a type in which a color image is obtained by batch-transferring the toner image onto a sheet. In a color image forming apparatus using such an intermediate transfer member, it is necessary to clean waste toner remaining on the intermediate transfer member and the photosensitive member after transfer.

As a technique for cleaning the intermediate transfer member and the photosensitive member, for example, a technique disclosed in Japanese Patent Application Laid-Open No. 10-254251 is known. In this method, the waste toner of the intermediate transfer member is charged to a polarity opposite to the charging potential of the photosensitive member to transfer the waste toner of the intermediate transfer member to the photosensitive member, and the waste toner is removed by a cleaning device for the photosensitive member. The removed waste toner is collected by a waste toner collecting unit provided in the cleaning device.

[0004]

However, in the above-mentioned technique, the waste toner on the intermediate transfer member and the photosensitive member is collected in one waste toner collecting section, so that the size of the waste toner collecting section needs to be increased. There is a problem that the forming apparatus becomes large.

Accordingly, an object of the present invention is to provide an image forming apparatus that can be downsized.

[0006]

According to a first aspect of the present invention, there is provided an image bearing member for carrying a toner image by a plurality of color toners supplied from a developing means, and an intermediate member for transferring the toner image on the image bearing member. A transfer unit, a transfer unit for transferring a toner image from the intermediate transfer body to a transfer material, and a cleaning unit for removing and recovering waste toner from the image carrier; In the image forming apparatus in which the waste toner of the intermediate transfer body is transferred to the image carrier by charging the carrier to a polarity opposite to the charging potential of the carrier, and the waste toner transferred to the image carrier is removed by the cleaning unit, the cleaning unit includes: A collection unit for collecting only black waste toner and a collection unit for unspecified color collecting waste toner of an unspecified color.

According to the first aspect of the present invention, at the time of monochrome image formation in which an image is formed with black toner, the cleaning unit transfers the black toner image from the intermediate transfer member to the photosensitive member after transferring the black toner image onto the sheet. While removing the black waste toner (hereinafter referred to as “black waste toner”),
Collect in the black collection section. Further, at the time of forming a color image in which an image is formed with toners of arbitrary plural colors,
After transferring the toner images of a plurality of colors to the paper, the cleaning unit removes waste toners of a plurality of colors (hereinafter, referred to as “unspecified waste toner”) transferred from the intermediate transfer member to the photosensitive member. Collect in the collection section for unspecified colors.

[0008] Since separate collection units are used for the black waste toner and the unspecified waste toner, the black waste toner and the unspecified waste toner are collectively collected in one collection unit.
One collection unit can be reduced in size, and by dividing the collection unit into two, the degree of freedom in arranging the collection unit in the image forming apparatus is increased, so that the image forming apparatus can be downsized.

A second aspect of the present invention is directed to the first aspect of the present invention, wherein the full toner detecting unit detects that the waste toner collected in the black collecting unit and the unspecified color collecting unit is full. And a guide means for guiding the waste toner to either the black collecting section or the unspecified color collecting section, and when the full detecting section detects that the waste toner in one of the collecting sections is full, the guiding section is And guiding the waste toner to the other collecting section.

[0010] According to the second aspect of the present invention, the first aspect is provided.
When the full detecting unit detects that one of the collecting units is full, the guiding unit guides the waste toner to the other collecting unit, so that the black and unspecified colors can be obtained. Since the waste toner can be collected until the collecting unit is full, the two collecting units can be effectively used.

According to a third aspect of the present invention, in the second aspect, the guide means guides the waste toner to the unspecified color collecting section only when the black collecting section is full. It is characterized by the following.

According to the third aspect of the present invention, the second aspect is provided.
In addition to the same operation and effect as the invention described in the above, the guide means guides the waste toner to the unspecified color collection section only when the black collection section is full, so the black collection section has Mixing of waste toners of colors other than black can be prevented, and black waste toner can be recycled.

The invention described in claim 4 is the first to third aspects of the present invention.
The invention according to any one of the above, wherein at least one of the black recovery section and the unspecified color recovery section is provided inside the image carrier.

According to the fourth aspect of the present invention, the first aspect is provided.
The image forming apparatus according to any one of the first to third aspects has the same function and effect as the invention described above, and at least one of the black recovery section and the unspecified color recovery section is provided in an empty space inside the image carrier. This makes it possible to effectively use the empty space inside, and to collect a large amount of waste toner without increasing the size of the image forming apparatus.

[0015] The invention according to claim 5 provides the invention according to claims 1 to 4.
The invention according to any one of the above, further comprising a toner conveying means for conveying waste toner from the black collecting section to the developing means.

According to the fifth aspect of the present invention, there is provided the first aspect.
In addition to the same operation and effect as the invention described in any one of (1) to (4), the toner transporting unit transports the black waste toner collected by the black recovery unit to the developing unit, and the developing unit performs Development is performed using the transported black waste toner.

By providing the toner conveying means, the black waste toner in the black recovery section can be efficiently recycled, and the waste toner can be used up to its life. Further, since the black waste toner in the black recovery unit is transported to the developing unit, the black recovery unit can be further reduced in size.

[0018]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram schematically showing a copying machine according to the present invention. As shown in FIG. 1, a copying machine (image forming apparatus) 1 capable of producing a full-color image generally includes a photosensitive belt 3 as an image carrier and a charging device 5 for applying a predetermined bias to the photosensitive belt 3. An exposure device 7 for forming an electrostatic latent image on the photoreceptor belt 3 based on image data read by a reading device (not shown); and a developing device for developing the electrostatic latent image on the photoreceptor belt 3 as a toner image ( (Developing means) 9, a transfer device 11 for transferring a toner image, and a cleaning device (cleaning means) 13 for removing and collecting waste toner remaining on the photosensitive belt 3 after the transfer.

The photoreceptor belt 3 is a negatively charged organic photoreceptor in this embodiment, and is rotated at a predetermined speed by a plurality of drive rollers (not shown) in the direction of arrow A in the figure. The surface of the photoreceptor belt 3 is uniformly negatively charged by applying a bias from a charging device 7 provided in contact with or in proximity to the photoreceptor belt 3. A corresponding electrostatic latent image is formed. Incidentally, the image carrier is not limited to the photoreceptor belt 3, and for example, a photoreceptor drum may be used.

The developing device 9 supplies four photosensitive drums 3 with black (K), yellow (Y), cyan (C), and magenta (M) toners each having a negative toner polarity. Belts 9a, 9b, 9c and 9d, and the photosensitive belt 3
The electrostatic latent image formed thereon is developed as a toner image.

The transfer device 11 includes an intermediate transfer member 15 on which the toner image on the photosensitive belt 3 is primarily transferred, and an intermediate transfer member 15.
Transfer roller (transfer means) 17 for secondary transfer of the toner image to the paper P, and a waste toner charging device 16 for applying a positive charge to the waste toner remaining on the intermediate transfer body 15 after the transfer. . The intermediate transfer member 15 rotates in the direction of arrow B in the figure, and the toner image on the photosensitive belt 3 is transferred to the intermediate transfer member 15 at the primary transfer portion 19 with the photosensitive belt 3.

That is, when a color image is formed in which a color image is formed using a plurality of color toners, the photosensitive belt 3
A toner image of a predetermined color is sequentially formed on the top, and each time,
The toner images of each color are sequentially transferred to the intermediate transfer body 5. The plurality of color toner images sequentially transferred and superimposed on the intermediate transfer member 5 are collectively transferred onto the sheet P by the transfer roller 17. Further, when forming a monochrome image in which an image is formed only with black toner, the black toner image on the photosensitive belt 3 is transferred to the intermediate transfer body 5 and then transferred to the paper P by the transfer roller 17.

The transfer roller 17 applies a predetermined secondary transfer bias (positive bias) to the sheet P passing between the transfer roller 17 and the intermediate transfer member 15, thereby causing the toner on the intermediate transfer member 15 to be transferred. The image is transferred onto the paper P. The toner image transferred to the paper P is fused and fixed by a fixing device (not shown) to become a final image.

The waste toner charging device 16 applies a charge of the opposite polarity (positive in this embodiment) to the charge potential of the photosensitive belt 3 to the waste toner remaining on the intermediate transfer member 15 after the transfer. This is to make the charge amount of the waste toner on the intermediate transfer member 15 uniform. This waste toner is transferred to the primary transfer unit 1
At 9, the toner image is reversely transferred to the photoreceptor belt 3 and collected while being removed by the cleaning device 13.

The cleaning device 13 includes a black cleaning unit 21 for removing and collecting black waste toner;
Black waste toner, yellow waste toner, cyan waste toner,
And an unspecified color cleaning unit 23 for removing and collecting any of the magenta waste toner, and a driving unit (guide unit) 3 for driving the cleaning units 21 and 23.
3 and a control unit 35 for controlling the driving of the driving unit 33.

The black cleaning unit 21 includes a black cleaning blade 25 for scraping off black waste toner remaining on the photoreceptor belt 3 and a black waste toner bottle for collecting black waste toner scraped off by the black cleaning blade 25. (A recovery part for black) 27 are provided integrally. Further, in the black waste toner bottle 27, a black full detection sensor (full detection means) 31 for detecting that the inside of the black waste toner bottle 27 is full is disposed.

The unspecified color cleaning unit 2
3, a cleaning blade 37 for unspecified color that scrapes off unspecified waste toner remaining on the intermediate transfer member 5 and a waste toner for unspecified color that collects unspecified waste toner, similarly to the above-described cleaning unit 21 for black. And a waste toner bottle 39 for unspecified color, and a full detection sensor for unspecified color (full detection) similar to the full detection sensor 31 for black described above. Means) 32 are arranged.

By collecting the black waste toner and the unspecified waste toner in separate waste toner bottles 27 and 39, compared to collecting the black waste toner and the unspecified waste toner collectively in one waste toner bottle, One by one waste toner bottle 2
Since the waste toner bottles 27 and 39 can be reduced in size, and the waste toner bottles are divided into two, the degree of freedom in arranging the waste toner bottles 27 and 39 in the copying machine 1 is increased.
The size of the copying machine 1 can be reduced.

In the present embodiment, the full-color detection sensor 31 for black and the full-color detection sensor 32 for unspecified color include the light emitting element 3.
This is a reflection type photo sensor having 1a, 32a and light receiving elements 31b, 32b. The full-color detection sensor 31 for black and the full-color detection sensor 32 for unspecified color include a light emitting element 31a,
When the light transmittance of light traveling from 32a to the light receiving elements 31b and 32b decreases, it is detected that each of the waste toner bottles 27 and 39 is full, and a signal to the effect that the waste toner bottles 27 and 39 are full is sent to the control unit 33. I have.

In this embodiment, the reflection type photosensor is used as the fullness detecting means. However, for example, a piezoelectric sensor may be used, or the black and unspecified color waste toner bottle 2 may be used.
The fullness may be detected by measuring the change in the weight of the waste toner bottles 7 and 39. There is no particular limitation as long as the waste toner bottles 27 and 39 for black and unspecified colors can be detected to be full.

The drive unit 33 receives a detection signal from the full-color detection sensor 31 for black and the full-color detection sensor 32 for unspecified color and a signal from the operation unit 40 to control the control unit 35 for black. The cleaning unit 21 is moved to a contact position where the black cleaning blade 25 contacts the intermediate transfer member 5 and a retreat position where the black cleaning blade 25 separates from the intermediate transfer member 5. Similarly, the unspecified color cleaning unit 23 is moved to the contact position and the retreat position by the driving unit 33.

Next, the operation of the present embodiment will be described based on the above-described configuration and the flowchart of FIG. When a print signal is received from the operation unit 40 in step S1, it is determined in step S2 whether or not the mode is the monochrome image creation mode. If the mode is the monochrome image creation mode, the process proceeds to step S3, and the mode is not the monochrome image creation mode. In this case (in the case of the color image creation mode), the process proceeds to step S6.

In step S3, it is determined whether or not the waste toner bottle for black 27 is full.
Proceed to step S6, and if not full, step S6
In 4, the black cleaning blade 27 is located at the contact position, and the above-described printing operation (monochrome image forming operation) is performed. Then, in step S5, the printing operation is completed.

In steps S3 to S5, when a monochrome image is created, the driving unit 33 causes the black cleaning unit 21 to be located at the contact position, and the unspecified color cleaning unit 23 to be located at the retracted position. . Thereafter, the black cleaning blade 25 scrapes black waste toner reversely transferred from the intermediate transfer body 5 to the photoreceptor belt 3, and the black waste toner bottle 27 scrapes black waste toner scraped off by the black cleaning blade 25. Collect the toner.

In step S6, it is determined whether the waste toner bottle 39 for unspecified color is full. If it is full, the printing operation is stopped in step S8, and the operation unit 40 A warning is displayed to indicate that the waste toner bottle 39 for the specific color is full.

If it is determined in step S6 that the waste toner bottle 39 for unspecified color is not full, the process proceeds to step S6.
In 7, the printing operation is performed after the unspecified color cleaning blade 37 is positioned at the contact position and the black cleaning blade 25 is positioned at the retracted position.

In steps S6 and S7, when a color image is created or when the black waste toner bottle 27 is full, the driving unit 33 causes the unspecified color cleaning unit 21 to be positioned at the contact position. When the black cleaning unit 21 is located at the retracted position, the waste toner of the photoreceptor belt 3 is guided to the color ash toner bottle 39 via the unspecified color cleaning blade 37. Specifically, the cleaning blade 37 for unspecified color scrapes off unspecified waste toner or black waste toner transferred from the intermediate transfer body 5 to the photoreceptor belt 3,
The unspecified color waste toner bottle 39 collects the scraped unspecified waste toner or black waste toner.

When the waste toner bottle for black 27 is full, the driving unit 33 operates the unspecified waste toner bottle 3.
Since the waste toner is collected by the waste toner bottle 9 until the two waste toner bottles 27 and 39 become full, the two waste toner bottles 27 and 39 can be effectively used. When a color image is created and when the waste toner bottle 27 for black is full, waste toner is collected in the waste toner bottle 39 for unspecified color. The toner can be prevented from being mixed, and the waste black toner collected in the waste toner bottle for black 27 can be recycled.

Next, other embodiments will be described. In the description, the same parts as those described above are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 3 is a configuration diagram schematically showing the vicinity of a photosensitive belt according to the second embodiment. In the second embodiment, as shown in FIG. 3, a black waste toner bottle 27 and an unspecified color waste toner bottle 39 are integrally provided in a hollow portion in the photoreceptor belt 3, and The black waste toner scraped off by the cleaning blade 25 is collected in the black waste toner bottle 27 via the black recovery device 45, and the unspecified waste toner of the unspecified color cleaning blade 37 is collected by the color collection device 47. Is different from the first embodiment in that the waste toner is collected in the waste toner bottle 39 for unspecified colors via the.

In the present embodiment, the collection device 45 for black color is provided by an air flow generated by a pump (not shown).
The black waste toner scraped off by the black cleaning blade 27 is transported to the black waste toner bottle 27. Similarly, the color collecting device 47 also removes the unspecified waste toner scraped off by the unspecified color cleaning blade 37 by the airflow generated by the pump to the unspecified color waste toner bottle 3.
9.

In the present embodiment, the recovery devices 45 and 47 using pumps are used, but the present invention is not limited to this. For example, the black cleaning blade 27 may be used.
May be disposed above the black waste toner bottle 27, and the waste toner may be dropped from the black cleaning blade 27 toward the black waste toner bottle 27 by gravity. The scraped black waste toner is transferred to a black waste toner toner bottle 27.
It should just be able to be conveyed. The same applies to the cleaning blade 37 for unspecified color and the waste toner bottle 39 for unspecified color.

In the second embodiment, the waste toner bottle 27 for black and the waste toner bottle 39 for unspecified color are provided in the empty space inside the image carrier to make the empty space in the image forming apparatus effective. It is possible to collect a large amount of waste toner without utilizing the image forming apparatus. Further, if the respective toner bottles 27 and 39 are provided detachably from the photoreceptor belt 3, when each of the waste toner bottles 27 and 39 becomes full, it may be replaced with a new waste toner bottle. Maintenance becomes easy.

FIG. 4 is a configuration diagram schematically showing the vicinity of the photoreceptor belt according to the third embodiment. As shown in FIG. 4, a waste toner bottle 39 for an unspecified color is disposed in a hollow portion of the photoreceptor belt 3, and the waste toner of the black toner bottle 27 is transferred to a toner hopper (not shown) of a developing unit 9a for black. ), A toner conveying device (toner conveying means) 5 for conveying.
1 is different from the first embodiment.

The toner transporting device 51 transports black toner from the black toner bottle 27 to the developing device 9a by an airflow from a pump, similarly to the black recovery device 45 of the second embodiment. In addition, the toner conveying device 51
Is not limited to the one using a pump. For example, black waste toner can be
a.

In the third embodiment, the provision of the toner conveying device 51 allows the black waste toner in the black toner bottle 27 to be efficiently recycled, and the waste toner can be used up to the end of its life. Further, since the waste toner in the black waste toner bottle 27 is transported to the developing device 9a, the size of the black waste toner bottle 27 can be further reduced.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, as shown in FIG. 5, a black recovery chamber (black recovery unit) 63 and an unspecified color collection chamber (unspecified color collection unit) are formed by a partition plate 62 provided in one toner bottle 60. 65, and the black waste toner and the unspecified waste toner are removed by the swinging member (guide means) 67 swinging in the direction of arrow C.
You may be made to guide to either.

As shown in FIG. 6, in addition to the unspecified color waste toner bottle 39 integrated with the cleaning blade 37, an inner unspecified color waste toner bottle 49 provided in the photoreceptor belt 3 is provided. Alternatively, a large amount of unspecified waste toner having a remaining toner amount larger than that of the black toner may be collected.

In this embodiment, the waste toner is collected in the unspecified color waste toner bottle 39 only when the black waste toner bottle 27 is full. When the is full, the waste toner may be collected in the waste toner bottle 27 for black.

Although the present invention is applied to the copying machine 1, the present invention is not limited to this. For example, the present invention can be applied to an image forming apparatus such as a laser beam printer and a facsimile to obtain the same effects.

[0051]

According to the first aspect of the present invention, since the black waste toner and the unspecified waste toner use separate collection units,
Compared to collectively collecting black waste toner and unspecified waste toner in one collection unit, each collection unit can be reduced in size, and by dividing the collection unit into two, the image is recovered. Since the degree of freedom in arranging the collecting unit in the forming apparatus is increased, the size of the image forming apparatus can be reduced.

According to the second aspect of the present invention, the same effects as those of the first aspect of the invention can be obtained, and when the full detecting unit detects that one of the collecting units is full, the guiding unit replaces the waste toner with the other. By guiding to the collection unit, the toner can be collected until the black and unspecified color collection units are full, so that the two collection units can be used effectively.

According to the third aspect of the invention, the same effect as that of the second aspect of the invention can be obtained, and the guiding means can
The waste toner is guided to the unspecified color collection unit only when the black collection unit is full, so that it is possible to prevent the black collection unit from being mixed with waste toner other than black. Recycling of toner becomes possible.

According to the fourth aspect of the present invention, the same effects as those of the first to third aspects can be obtained, and at least one of the black collecting section and the unspecified color collecting section has an image bearing member. By being provided in the empty space inside the body, the empty space in the image forming apparatus can be effectively utilized, and a large amount of waste toner can be collected without increasing the size of the image forming apparatus. Can be.

According to the fifth aspect of the present invention, the same effects as those of the first to fourth aspects of the invention are obtained, and the provision of the toner conveying means allows the black waste toner in the black recovery section to be removed. Can be recycled efficiently,
Black waste toner can be used up to its life. Further, since the black waste toner in the black recovery unit is transported to the developing unit, the black recovery unit can be further reduced in size.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a color copying machine according to the present invention.

FIG. 2 is a flowchart illustrating a flow of control performed by a control unit.

FIG. 3 is a configuration diagram schematically showing the vicinity of a photoreceptor belt according to a second embodiment.

FIG. 4 is a configuration diagram schematically showing the vicinity of a photoreceptor belt according to a third embodiment.

FIG. 5 is a configuration diagram schematically showing the vicinity of a photosensitive belt according to a modification.

FIG. 6 is a configuration diagram schematically showing the vicinity of a photosensitive belt according to a modification.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 copier (image forming apparatus) 3 photoreceptor belt (image carrier) 9 developing device (developing unit) 13 cleaning device (cleaning unit) 15 intermediate transfer member 17 transfer roller (transfer unit) 27 waste toner bottle for black (black Collection unit for 31) Black full detection sensor (full detection unit) 32 Full detection sensor for unspecified color 33 Drive unit (guide unit) 39 Waste toner bottle for unspecified color (collection unit for unspecified color) 51 Toner transport device (Toner conveying means) 67 Swinging member (guide means)

Claims (5)

[Claims] An image carrier that carries a toner image with toners of a plurality of colors supplied from a developing unit; an intermediate transfer body onto which the toner image of the image carrier is transferred; and a toner image from the intermediate transfer body to a transfer material. And a cleaning unit that removes and collects waste toner remaining on the image carrier after the transfer, so that the waste toner of the intermediate transfer body after the transfer has a polarity opposite to the charging potential of the image carrier. In an image forming apparatus in which the waste toner of the intermediate transfer body is transferred to the image carrier by charging, and the waste toner transferred to the image carrier is removed by the cleaning unit, the cleaning unit collects only the black waste toner. An image forming apparatus comprising: a black collecting unit; and an unspecified color collecting unit for collecting an unspecified color waste toner. 2. A full detecting means for detecting that the waste toner collected in the black collecting section and the unspecified color collecting section is full, and one of the black collecting section and the unspecified color collecting section. Guide means for guiding waste toner, and when the full state detecting means detects fullness of waste toner in one recovery section, the guide means guides waste toner to the other recovery section. The image forming apparatus according to claim 1. 3. The image forming apparatus according to claim 2, wherein the guide unit guides the waste toner to the unspecified color collection unit only when the black collection unit is full. 4. The image forming apparatus according to claim 1, wherein at least one of the black collecting section and the unspecified color collecting section is provided inside the image carrier. . 5. The image forming apparatus according to claim 1, further comprising a toner conveying unit that conveys waste toner from the black recovery unit to the developing unit.