JP5116401B2 - Image forming apparatus - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine or a printer, and more particularly to an image forming apparatus in which a plurality of process cartridges including at least an image carrier such as an electrophotographic photosensitive drum are arranged. The present invention relates to an image forming apparatus that is detachable from a main body.

(Description of electrophotographic technology)
In an electrophotographic image forming apparatus using electrophotographic technology, a drum-shaped electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”), which is an image carrier uniformly charged by a charging unit, is used. A latent image is formed on the photosensitive drum by selective exposure by an exposure unit. The latent image is developed with a developer (hereinafter referred to as “toner”), the developed image is transferred to a recording material (paper, OHT, etc.), and the transferred image on the recording material is pressurized by a fixing unit.・ Record images by heating and fixing. After the toner image transfer process is completed, the residual toner is removed by the cleaning unit, and then the image forming process is started again from the charging.

(Formation of multicolor images)
As a means for forming a multicolor image using the electrophotographic technique, a system using a plurality of process cartridges (hereinafter simply referred to as “cartridges”) is known. In particular, when forming a full-color image, each color (yellow Y, magenta M, cyan C, black B) is used in order to increase the speed and provide a high-quality color image while simplifying operability. configuration formed by arranging a cartridge that performs image formation in a line (tandem type) is adopted.

  In such an image forming apparatus, it is also widely performed that a photosensitive drum and process means such as a cleaning device, a charging device, and a developing device are made into a cartridge and detachable from the main body of the image forming device.

For example, Patent Document 1 describes that a process cartridge has a pre-exposure lamp 3 that adjusts the charge on the surface of the photosensitive drum 1 after cleaning. In Patent Document 2, a cleaning exposure LED63 is pre-exposure means is described which is provided in the apparatus main body.
JP 2001-324854 A JP 2004-170866 A

  If the pre-exposure means is provided in each process cartridge, the cost of the process cartridge may increase. In addition, since the pre-exposure means must be disposed between the cleaning device and the charging device, there is a restriction on the space to be provided.

  Further, in the configuration in which the pre-exposure unit is provided in the image forming apparatus main body, it is necessary to install the pre-exposure unit in a place that does not affect the process cartridge attaching / detaching operation.

  The above description also applies to an electrostatic latent image exposure apparatus that forms an electrostatic latent image on a photosensitive drum.

  An object of the present invention is to provide an image forming apparatus having a plurality of cartridges, wherein one of the cartridges does not require an exposure device such as a pre-exposure device or an electrostatic latent image exposure device, thereby reducing the number of parts. Another object of the present invention is to provide an image forming apparatus including a cartridge with a lower price.

  Another object of the present invention is to provide an image forming apparatus in which there are no restrictions on the exposure apparatus and the degree of freedom in designing the image forming apparatus main body and the cartridge can be increased.

The above object is achieved by the image forming apparatus according to the present invention. In summary, the present invention may have a plurality of process cartridges for forming the image forming apparatus can and to toner images of different colors attached to and detached from the main body, supported by the recording material bearing member, the toner image formed in the process cartridge In the image forming apparatus that forms a color image by transferring to a recording material that is conveyed or transferred to an intermediate transfer member, each of the plurality of process cartridges includes at least an image carrier on which a toner image is formed, A developing device that supplies toner to the image carrier, and a cleaning device that removes and collects residual toner from the image carrier, the process cartridges disposed adjacent to each other, wherein the recording material carrier or a process cartridge which is arranged located downstream side in the moving direction of the intermediate transfer member is located upstream Includes an exposure device which acts on the image bearing member adjacent process cartridges, the plurality of process cartridges, a process cartridge disposed positioned on the most upstream side in the moving direction is provided with said exposure apparatus The image forming apparatus is characterized in that it is not .

  According to the present invention, it is not necessary to provide an exposure device in one cartridge among a plurality of cartridges, so that the number of parts can be reduced, and an image forming apparatus having a cartridge with a lower price can be provided. Further, when the cartridge has an exposure device that acts on its own image carrier, the arrangement location is limited, but according to the present invention, the adjacent cartridge can be used as the arrangement location of the exposure device. The choice of the arrangement place increases and the design freedom improves. Furthermore, the space can be reduced compared to the configuration in which the exposure apparatus is provided in the main body of the image forming apparatus corresponding to all cartridges, and a compact design is possible.

  Hereinafter, an image forming apparatus and a process cartridge according to the present invention will be described in more detail with reference to the drawings.

Example 1
Figure 1 shows a schematic sectional view of an embodiment of an image forming apparatus according to the present invention. In this embodiment, the image forming apparatus 100 is an electrophotographic color image forming apparatus. In this embodiment, a plurality of four-color process cartridges (hereinafter simply referred to as “cartridges”) constituting the image forming unit. .) 8 (8Y, 8M, 8C, 8B). Each cartridge 8 (8Y, 8M, 8C, 8B) is detachably mounted on the image forming apparatus main body 100A by mounting means (not shown).

(Image forming device body configuration)
As described above, in FIG. 1, each of the four color cartridges 8 (8Y, 8M, 8C, 8B) of yellow (Y), magenta (M), cyan (C), and black (B) is an image forming apparatus. The main body 100A is detachable.

  In addition, the cartridges 8 are arranged in a row along the intermediate transfer belt T as an intermediate transfer member, with four color cartridges 8Y, 8M, 8C, and 8B. In this embodiment, the cartridges 8Y, 8M, 8C, and 8B are arranged horizontally along the intermediate transfer belt T, but the present invention is not limited to this, and the cartridges may be arranged in an inclined manner. The intermediate transfer belt T, which is a belt-shaped intermediate transfer body, is stretched around the support rollers 20a, 20b, and 20c, and is rotatable in the direction of the arrow.

  Further, the image forming apparatus main body 100A has an electrostatic latent image forming exposure apparatus corresponding to each cartridge 8 (8Y, 8M, 8C, 8B). In this embodiment, the laser unit 101 (101Y, 101M, 101C, 101B).

  In this embodiment, the recording paper cassette 105, which is positioned below the image forming apparatus main body 100A, is fed to feed the recording paper P as a recording material to the secondary transfer portion T2 of the intermediate transfer belt T. A paper roller 106, a conveyance roller 107, and the like are disposed. As will be described in detail later, a transfer roller 21 as a secondary transfer device is disposed in the secondary transfer portion T2. In addition, the fixing device 110, the discharge roller 111, and the recording paper P on which the color image on the intermediate transfer belt T is transferred by the action of the transfer roller 21 in the secondary transfer portion T2 A paper discharge tray 112 is disposed.

(Image forming operation)
Referring to FIGS. 1 and 2, will be described an image forming operation of the image forming apparatus 100 of the present embodiment.

To the cartridge 8 (8Y, 8M, 8C, 8B), a drum-shaped electrophotographic photosensitive member as an image carrier, that is, a photosensitive drum 1 (1Y, 1M, 1C, 1B) is rotatably attached. . Around each photosensitive drum 1, a charging device 17 (17Y, 17M, 17C, 17B), an exposure device 101 (101Y, 101M, 101C, 101B), and a developing device 4 (4Y, 4M, 4C, 4B) are arranged. Has been. Further, a transfer roller 19 (19Y, 19M, 19C, 19B) as a primary transfer device is disposed around the photosensitive drum 1, and constitutes a primary transfer portion T1 (T1Y, T1M, T1C, T1B). . Further, around the photosensitive drum 1, the cleaning equipment 1 8 (18Y, 18M, 18C , 18B) are disposed.

  While the photosensitive drum 1 (1Y, 1M, 1C, 1B) rotates, the surface thereof is uniformly charged by the charging device 17 (17Y, 17M, 17C, 17B).

  Next, in this embodiment, first, an electrical signal corresponding to the yellow component is transmitted to a laser unit 101Y as an electrostatic latent image exposure apparatus. As a result, the light LY is reflected by the reflection mirror 102Y, and is irradiated onto the surface of the photosensitive drum 1Y through the exposure opening 12Y. As a result, an electrostatic latent image corresponding to the image signal is formed on the photosensitive drum 1Y.

  In the process cartridge 8Y, a developing bias is applied to the developing roller 4aY of the developing device 4Y facing the photosensitive drum 1Y on which the electrostatic latent image is formed. Thus, a developer image (toner image) is formed on the photosensitive drum 1Y according to the latent image. That is, the developing device 4Y develops the latent image into a toner image. The toner image formed on the photosensitive drum 1Y is transferred to the intermediate transfer belt T by the transfer roller 19Y as a primary transfer device at the primary transfer portion T1Y.

  Similarly, in the process cartridges 8M, 8C, and 8B corresponding to the other colors, in this embodiment, magenta (M), cyan (C), and black (B) components, the toner images are the photosensitive drums 1M and 1C. 1B. The toner images on the photosensitive drums 1M, 1C, and 1B are superimposed and transferred onto the yellow toner image on the intermediate transfer belt T by the transfer rollers 19M, 19C, and 19B at the primary transfer portions T1M, T1C, and T1B. A color toner image is formed.

  The color toner image on the intermediate transfer belt T is transferred onto the recording paper P by a secondary transfer roller 21 as a secondary transfer device of the secondary transfer portion T2. Then, the recording paper P passes through a conveyance path such as a dotted line A, is subjected to pressure and heat fixing of the toner image by the fixing device 110, and then is conveyed to the paper discharge tray 112.

  Here, an electrostatic latent image corresponding to an image signal is formed on the photosensitive drum 1 using the laser unit 101, but as shown in FIG. 3, an LED exposure unit 201 (201Y using LED) is used. , 201M, 201C, 201B). In this case as well, an electrostatic latent image corresponding to the image signal is formed on the photosensitive drum 1 (1Y, 1M, 1C, 1B) with the same configuration as described in the above embodiment, and the toner image Is formed. Since this configuration is well known to those skilled in the art, members having the same configuration and function are denoted by the same reference numerals, and detailed description thereof is omitted.

(Cartridge configuration)
As shown in FIGS. 1 and 2, each cartridge 8 includes a photosensitive drum 1 which is an image carrier that is rotatably supported, a charging device 17 that uniformly charges the surface of the photosensitive drum 1, and the photosensitive drum. A cleaning device 18 for cleaning the toner remaining on the body drum 1 is provided. The cleaning device 18 includes a cleaning blade that removes residual toner from the photosensitive drum 1 and a container that collects residual toner removed from the photosensitive drum 1 by the cleaning blade.

  In this embodiment, the charging device 17 uses a contact type charging device using a conductive roller formed in a roller shape, but a non-contact corona charging device may be used. The cleaning device 18 may have a configuration including a cleaning unit such as a fur brush or a magnetic brush, instead of a configuration including a blade as a cleaning unit.

  In this embodiment, the cartridges 8Y, 8M, and 8C are provided with pre-exposure devices 10Y, 10M, and 10C for removing charges on the surface of the photosensitive drum 1 after cleaning and making the potential uniform. Details of the pre-exposure device 10 will be described later.

  Further, as described above, each developing device 4 (4Y, 4M, 4C, 4B) includes the developing roller 4a (4aY, 4aM, 4aC, 4aB) that is a developer carrier (see FIG. 2). Further, each developing device 4 includes a developing blade 5 (5Y, 5M, 5C, and 5B) that is a developer regulating member that regulates the thickness of the toner on the developing roller 4a, and a toner containing portion (toner containing the toner). Container) 6 (6Y, 6M, 6C, 6B). In addition, the toner storage unit 6 includes a transport unit (not shown) that transports toner toward the developing roller 4.

(Pre-charge exposure device)
According to this embodiment, the pre-exposure device 10 (10a, 10Y) for removing the charge on the surface of the photosensitive drum after cleaning and making the potential uniform for all the cartridges 8 (8Y, 8M, 8C, 8B). 10M, 10C).

  Examples of the light source of the pre-exposure device 10 include a lamp and an LED. One pre-exposure device 10a in the pre-exposure device 10 is provided in the image forming apparatus main body 100A, and the other three pre-exposure devices 10Y, 10M, and 10C are provided in the cartridges 10Y, 10M, and 10C, respectively. It has been.

  More specifically, in FIG. 2, the light 10b of the pre-exposure device 10a provided in the image forming apparatus main body 100A acts on the photosensitive drum 1Y of the cartridge 8Y adjacent on the upstream side in the moving direction of the intermediate transfer belt T. is doing.

  The light 10b of the pre-exposure device 10Y provided in the cartridge 8Y acts on the photosensitive drum 1M of the cartridge 8M adjacent on the upstream side in the moving direction of the intermediate transfer belt T.

  Similarly, the light 10b of the pre-exposure device 10M of the cartridge 8M acts on the photosensitive drum 1C of the adjacent cartridge 8C on the upstream side in the moving direction of the intermediate transfer belt T. Further, the light 10b of the pre-exposure device 10C of the cartridge 8C acts on the photosensitive drum 1B of the cartridge 8B adjacent on the upstream side in the moving direction of the intermediate transfer belt T.

  The cartridge 8B is not provided with a pre-exposure device.

  That is, there are two types of cartridges 8 (8Y, 8M, 8C, 8B): the first cartridge (8Y, 8M, 8C) having the pre-exposure device 10 and the second cartridge 8B not having the pre-exposure device 10. Can be divided into cartridges.

  Thus, according to the present embodiment, in the cartridges 8 arranged adjacent to each other, the process cartridges arranged on the downstream side in the moving direction of the intermediate transfer belt T are located on the upstream side. A pre-exposure device 10 that acts on the photosensitive drum 1 of the adjacent process cartridge is provided. A pre-exposure provided on the main body 100A of the image forming apparatus is provided on the cartridge 8, which is disposed on the most downstream side in the moving direction of the intermediate transfer belt T, in this embodiment, on the photosensitive drum 1Y of the cartridge 8Y. The device 10a operates.

  Compared to the conventional configuration in which all the cartridges 8 are provided with the pre-exposure device 10, one cartridge, in this embodiment, the cartridge 8B located on the most upstream side in the moving direction of the intermediate transfer belt T, The pre-exposure device 10 need not be provided. Therefore, there is an advantage that the number of parts can be reduced and a cartridge with a lower price can be provided, and as a result, the cost of the image forming apparatus can be reduced.

  Further, when each cartridge 8 has a pre-exposure device 10 that acts on its own photosensitive drum 1, the location of the pre-exposure device 10 is limited. However, since the adjacent cartridge 8 can be used as the location of the pre-exposure apparatus 10 as in this embodiment, there are advantages in that the choice of location is increased and the degree of design freedom is improved.

Further, the present embodiment has the following merits compared to the configuration in which the pre- exposure device 10 is installed in the image forming apparatus main body 100A corresponding to all the cartridges 8 arranged in the image forming apparatus main body 100A. In other words, in this embodiment, the pre-exposure device 10a provided in the image forming apparatus main body 100A is only provided at the end of the cartridge 8Y and does not have to be provided between the cartridges 8. Therefore, the space can be reduced and the size is compact. Design becomes possible.

  Here, according to the present embodiment, as shown in FIGS. 2 and 5, each cartridge 8 is provided with a slit 13 (13 </ b> Y, 13 </ b> M, 13 </ b> C, 13 </ b> B) between the charging device 17 and the cleaning device 18. . As shown in FIG. 2, the slit 13 corresponds to the light source of the pre-exposure device 10 disposed adjacent to the slit 13, and can apply the light 10 b of the pre-exposure device 10 to the photosensitive drum 1.

  Therefore, when the pre-exposure device 10 is provided in the cartridge 8, in this embodiment, the cartridges 8Y, 8M, and 8C, the pre-exposure device 10 is located at a location corresponding to the slit 13 of the adjacent cartridge 8 on the upstream side in the belt movement direction. What is necessary is just to provide (refer FIG. 2, FIG. 4). Therefore, in this embodiment, the pre-exposure devices 10Y, 10M, and 10C are provided in a part of the toner storage containers 6Y, 6M, and 6C of the cartridges 8Y, 8M, and 8C.

  Further, as in the modified embodiment shown in FIG. 6, the pre-exposure devices 10Y, 10M, and 10C of the cartridges 8Y, 8M, and 8C and the pre-exposure device 10a of the apparatus main body 100A are spaced apart from each other. May be placed. In this case, as shown in FIG. 7, the cartridge 8 (8Y, 8M, 8C, 8B) has a hole at a position corresponding to the pre-exposure device 10 (10a, 10Y, 10M, 10C) instead of the slit 13. 14 (14Y, 14M, 14C, 14B) may be formed.

  In the above-described embodiment, the case where the full-color image is formed with four colors of yellow, magenta, cyan, and black is shown. However, the present invention is not limited to this, but three colors of yellow, magenta, and cyan, or further different colors. Needless to say, a full color image may be formed with four or more colors to which is added.

Example 2
Figure 8 shows a schematic sectional view of a second embodiment of an image forming apparatus according to the present invention. In this embodiment, the image forming apparatus 100 is an electrophotographic color image forming apparatus as in the first embodiment, and a plurality of four-color process cartridges 8 constituting the image forming unit are formed in this embodiment. (8Y, 8M, 8C, 8B). Each cartridge 8 (8Y, 8M, 8C, 8B) is detachably mounted on the image forming apparatus main body 100A by mounting means (not shown).

(Image forming device body configuration)
As described above, in FIG. 8, each of the four color cartridges 8 (8Y, 8M, 8C, 8B) of yellow (Y), magenta (M), cyan (C), and black (B) is an image forming apparatus. The main body 100A is detachable.

  In addition, the cartridges 8 are arranged in such a manner that four color cartridges 8Y, 8M, 8C, and 8B are arranged horizontally with respect to the intermediate transfer belt T as an intermediate transfer member. The intermediate transfer belt T is stretched around the support rollers 20a, 20b, and 20c and is rotatable in the direction of the arrow.

  Further, electrostatic latent image exposure devices 301 (301a, 301Y, 301M, 301C) corresponding to the respective colors, that is, the exposure device 301a is provided in the image forming apparatus main body 100A, and the exposure devices 301Y, 301M, 301C are respectively provided. The cartridges 8Y, 8M, and 8C are provided. Details of the electrostatic latent image exposure apparatus 301 will be described later.

  In this embodiment, a recording paper cassette 105, a paper feed roller 106, a transport roller 107, and the like are disposed below the image forming apparatus main body 100A. The recording paper P as the recording material is sent from the recording paper cassette 105 to the secondary transfer portion T2 of the intermediate transfer belt T on which the transfer roller 21 as the secondary transfer device is arranged by the paper feed roller 106 and the transport roller 107. Be paid. Further, the fixing device 110, the paper discharge roller 111, and the paper discharge along the conveyance path of the recording paper P on which the color image on the intermediate transfer belt T is transferred by the action of the transfer roller 21 in the secondary transfer portion T2. A tray 112 is arranged.

(Image forming operation)
The image forming apparatus of the present embodiment is the same as the image forming operation of the image forming apparatus 100 of the first embodiment described above with reference to FIGS.

That is, the cartridge 8 (8Y, 8M, 8C, 8B) has a drum-shaped electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) 1 (1Y, 1M, 1C, 1B) as an image carrier. It is attached so that it can rotate freely. Around each photosensitive drum 1, a charging device 17 (17Y, 17M, 17C, 17B), an exposure device 301 (301a, 301Y, 301M, 301C), and a developing device 4 (4Y, 4M, 4C, 4B) are arranged. Has been. Further, around the photosensitive drum 1, a transfer roller 19 (19Y, 19M, 19C, 19B) as a primary transfer device is disposed in the primary transfer portion T1 (T1Y, T1M, T1C, T1B). Around the photosensitive drum 1, the cleaning equipment 1 8 (18Y, 18M, 18C , 18B) are disposed.

  While the photosensitive drum 1 (1Y, 1M, 1C, 1B) rotates, the surface thereof is uniformly charged by the charging device 17 (17Y, 17M, 17C, 17B).

  Next, in this embodiment, first, an electrical signal corresponding to the yellow component is transmitted to a laser unit 301a as an exposure apparatus. Thus, the surface of the photosensitive drum 1Y is irradiated through the exposure opening 12Y. As a result, an electrostatic latent image corresponding to the image signal is formed on the photosensitive drum 1Y.

  In the process cartridge 8Y, a developing bias is applied to the developing roller 4aY of the developing device 4Y facing the photosensitive drum 1Y on which the electrostatic latent image is formed. Thus, the developing device 4Y develops the latent image and forms a developer image on the photosensitive drum 1Y according to the latent image. The toner image formed on the photosensitive drum 1Y is transferred to the intermediate transfer belt T by a transfer roller 19Y as a primary charging unit.

  Similarly, toner images are formed on the photosensitive drums 1M, 1C, and 1B also in the process cartridges 8M, 8C, and 8B corresponding to other colors, in this embodiment, magenta, cyan, and black components. The toner images on the photosensitive drums 1M, 1C, and 1B are transferred onto the yellow toner image on the intermediate transfer belt T by the transfer rollers 19M, 19C, and 19B, and a color toner image is formed.

  The color toner image on the intermediate transfer belt T is transferred to the recording paper P by the secondary transfer roller 21. Then, the recording paper P passes through a conveyance path such as a dotted line A, and after the toner image is pressed and heated and fixed by the fixing device 110, the recording paper P is conveyed to the paper discharge tray 112.

(Cartridge configuration)
In this embodiment, the cartridge 8 is configured similarly to the cartridge 8 of Example 1. That is, each cartridge 8 includes a photosensitive drum 1 that is an image carrier that is rotatably supported, a charging device 17 that uniformly charges the surface of the photosensitive drum 1, and toner remaining on the photosensitive drum 1. A cleaning device 18 for cleaning is provided. The cleaning device 18 includes a cleaning blade that removes residual toner from the photosensitive drum 1 and a container that collects residual toner removed from the photosensitive drum 1 by the cleaning blade.

  Here, the charging device 17 uses a contact-type charging device using a conductive roller formed in a roller shape in FIG. 8, but a non-contact corona charging device may also be used. The cleaning device 18 may be configured to have a cleaning unit such as a fur brush or a magnetic brush, instead of a configuration including a blade as the cleaning unit.

  In the present embodiment, the cartridge 8 (8Y, 8M, 8C, 8B) is provided with pre-exposure devices 10Y, 10M, 10C, 10B for removing charges on the surface of the photosensitive drum 1 after cleaning. Examples of the light source of the pre-exposure device 10 include a lamp and an LED.

  Each developing device 4 (4Y, 4M, 4C, 4B) includes a developing roller 4a (4aY, 4aM, 4aC, 4aB) that is a developer carrying member, as in the first embodiment. Further, each developing device 4 includes a developing blade 5 (5Y, 5M, 5C, and 5B) that is a developer regulating member that regulates the thickness of the toner on the developing roller 4a, and a toner containing portion (toner containing the toner). Container) 6 (6Y, 6M, 6C, 6B). In addition, the toner storage unit 6 includes a transport unit (not shown) that transports toner toward the developing roller 4.

(Exposure configuration for electrostatic latent image)
Also in this embodiment, as described above, exposure for electrostatic latent images as exposure means for irradiating the photosensitive drum 1 of each cartridge 8 (8Y, 8M, 8C, 8B) with light to form an electrostatic latent image. A device 301 is provided around the photosensitive drum. The electrostatic latent image exposure apparatus 301 can be a laser unit including a laser as a light source or an LED exposure unit including an LED as a light source.

  According to the present embodiment, one exposure device 301a of the electrostatic latent image exposure device 301 is provided in the image forming apparatus main body 100, and the other three exposure devices 301Y, 301M, and 301C are cartridges 8Y and 8M, respectively. , 8C.

  First, the light LY of the electrostatic latent image exposure device 301a provided in the image forming apparatus main body 100A passes through the exposure opening 12Y of the adjacent cartridge 8Y on the upstream side in the moving direction of the intermediate transfer belt T, and the photoreceptor of the cartridge 8Y. It acts on the drum 1Y.

  Further, the light LM of the electrostatic latent image exposure device 301Y provided in the cartridge 8Y passes through the exposure opening 12M of the adjacent cartridge 8M on the upstream side in the movement direction of the intermediate transfer belt T, and reaches the photosensitive drum 1M of the cartridge 8M. Works.

  Similarly, the light LC of the electrostatic latent image exposure device 301M provided in the cartridge 8M passes through the exposure opening 12C of the adjacent cartridge 8C on the upstream side in the movement direction of the intermediate transfer belt T, and the photosensitive drum 1C of the cartridge 8C. Act on. The light LB of the electrostatic latent image exposure device 301C of the cartridge 8C acts on the photosensitive drum 1B of the adjacent cartridge 8B through the exposure opening 12B of the adjacent cartridge 8B on the upstream side in the moving direction of the intermediate transfer belt T. To do.

  In this embodiment, the electrostatic latent image exposure device is not provided in the cartridge 8B.

  That is, the cartridge 8 (8Y, 8M, 8C, 8B) is the first cartridge (8Y, 8M, 8C) having the electrostatic latent image exposure device 301 and the first cartridge (8Y, 8M, 8C) not having the electrostatic latent image exposure device 301. It can be divided into two types of cartridges, ie, two cartridges 8B.

  Further, as understood above, each cartridge 8 is provided with an exposure opening 12 (12Y, 12M, 12C, 12B) for allowing the light L of the electrostatic latent image exposure apparatus 301 to pass therethrough. .

  As shown in FIGS. 9 and 10, the exposure openings, that is, the slits 12 are formed in the electrostatic latent image exposure devices 301Y, 301M, and 301C of the adjacent cartridge 8 and the static electricity provided in the image forming apparatus main body 100A. It corresponds to the light source of the electrostatic latent image exposure device 301 a, and the light L of the electrostatic latent image exposure device 301 can be applied to the photosensitive drum 1.

  As described above, the electrostatic latent image exposure device is not provided in one cartridge, in this embodiment, the black cartridge 8B, as compared with the configuration in which all the cartridges 8 are provided with the electrostatic latent image exposure device 301. Therefore, there is an advantage that the number of parts can be reduced and a cartridge with a lower price can be provided.

  Further, in the case where the cartridge 8 has the electrostatic latent image exposure device 301 that acts on its own photosensitive drum 1, the arrangement place is limited. However, in the present embodiment, since the electrostatic latent image exposure device 301 can be arranged in the adjacent cartridge 8 as well, there is an advantage that the choice of the arrangement location is increased and the degree of design freedom can be improved.

  In the above-described embodiment, the case where the full-color image is formed with four colors of yellow, magenta, cyan, and black is shown. However, the present invention is not limited to this, but three colors of yellow, magenta, and cyan, or further different colors. Needless to say, a full color image may be formed with four or more colors to which is added.

Example 3
Figure 11 shows a schematic configuration sectional view of a third embodiment of an image forming apparatus according to the present invention. In this embodiment, the image forming apparatus 100 is an electrophotographic color image forming apparatus as in the first and second embodiments, and a plurality of four-color processes in this embodiment are included in the image forming section. A cartridge 8 (8Y, 8M, 8C, 8B) is provided. Each cartridge 8 (8Y, 8M, 8C, 8B) is detachably mounted on the image forming apparatus main body 100A by mounting means (not shown).

  In the present embodiment, an arrangement configuration of the pre-exposure apparatus 10 similar to that of the first embodiment and an arrangement configuration of the electrostatic latent image exposure apparatus 301 similar to those of the second embodiment are employed.

  That is, according to the present embodiment, one exposure device 301a of the electrostatic latent image exposure device 301 is provided in the image forming apparatus main body 100, and the other three exposure devices 301Y, 301M, and 301C are respectively connected to the cartridge 8Y. , 8M, 8C. One pre-exposure device 10a of the pre-exposure device 10 is provided in the image forming apparatus main body 100A, and the other three pre-exposure devices 10Y, 10M, and 10C are provided in the cartridges 8Y, 8M, and 8C, respectively. It has been. Thus, the pre-exposure device 10 and the electrostatic latent image exposure device 301 are configured to act on the photosensitive drum 1 of the adjacent cartridge, and the configuration of the image forming apparatus main body 100A and the configuration of the process cartridge 8 are as follows. The same as in the first and second embodiments. Therefore, members having the same configuration and function as described in the first and second embodiments are denoted by the same reference numerals, and the description of the first and second embodiments is used, and detailed description thereof is omitted here.

  In this embodiment, compared to a configuration in which all the cartridges 8 are provided with the pre-exposure device 10 and the electrostatic latent image exposure device 301, the pre-exposure is performed on one cartridge in the cartridge 8, that is, the black cartridge 8B in this embodiment. Since there is no need to provide the apparatus 10 and the electrostatic latent image exposure apparatus 301, there is an advantage that the number of parts can be reduced and a cartridge with a lower price can be provided.

  Further, in the case where the cartridge 8 has the pre-exposure device 10 that acts on its own photosensitive drum 1 and the electrostatic latent image exposure device 301, the arrangement place is limited. However, as in this embodiment, since the pre-exposure device 10 and the electrostatic latent image exposure device 301 can be arranged in the adjacent cartridge 8 as well, there is an advantage that the choice of arrangement location is increased and the degree of freedom in design can be improved. .

  Further, the following advantages can be obtained as compared with the configuration in which the pre-exposure device 10 and the electrostatic latent image exposure device 301 are arranged in the image forming apparatus main body 100A corresponding to all cartridges. That is, the electrostatic latent image exposure device 301a of the image forming apparatus 100 according to the present embodiment is merely provided at the end of the cartridge 8Y and does not need to be provided between the cartridges 8. Similarly, the space can be reduced and a compact design becomes possible.

Example 4
In the above embodiments, the present invention has been described as an intermediate transfer type color image forming apparatus, but the present invention is not limited to this.

  In the present invention, for example, as shown in FIG. 12, the toner images formed on the surface of the photosensitive drum 1 are sequentially sequentially applied to the recording paper conveyed by the recording material carrier to each process cartridge 8. A direct transfer type color image forming apparatus in which a color image is transferred and recorded can also be provided.

  That is, in this embodiment, the color image forming apparatus 100 includes the four-color process cartridges 8 (8Y, 8M, 8C, 8B) as in the first, second, and third embodiments. Each cartridge 8 (8Y, 8M, 8C, 8B) is detachably mounted on the image forming apparatus main body 100A by mounting means (not shown).

  Further, the cartridge 8 is a four-color cartridge 8Y, 8M, 8C, 8B that conveys a recording material instead of the intermediate transfer belt T as an intermediate transfer member. Arranged in a line along the belt Ta. The conveyor belt Ta is stretched around the support rollers 20a, 20b, and 20c, and is rotatable in the direction of the arrow.

  Other configurations of the image forming apparatus main body 100A and the configuration of the process cartridge 8 are the same as those in the first embodiment. Accordingly, members having the same configuration and function as described in the first embodiment are denoted by the same reference numerals, and the description of the first embodiment is used, and detailed description thereof is omitted here.

  The configurations of the first, second, and third embodiments described above can also be applied to such a direct transfer type color image forming apparatus.

  Even in such a direct transfer type color image forming apparatus, the same operation and effect can be achieved by configuring in the same manner as in the first, second, and third embodiments.

1 is a schematic cross-sectional view of an embodiment of an image forming apparatus according to the present invention. FIG. 3 is a detailed cross-sectional view illustrating a cartridge mounting portion of the image forming apparatus according to the present invention. FIG. 5 is a schematic cross-sectional view of another embodiment of an image forming apparatus according to the present invention. It is a perspective view explaining the cartridge of one Example of this invention. It is a perspective view explaining the cartridge of one Example of this invention. It is a perspective view explaining the cartridge of the other Example of this invention. It is a perspective view explaining the cartridge of the other Example of this invention. FIG. 5 is a schematic cross-sectional view of another embodiment of an image forming apparatus according to the present invention. It is a perspective view explaining the cartridge of the other Example of this invention. It is a perspective view explaining the cartridge of the other Example of this invention. FIG. 5 is a schematic cross-sectional view of another embodiment of an image forming apparatus according to the present invention. FIG. 5 is a schematic cross-sectional view of another embodiment of an image forming apparatus according to the present invention.

Explanation of symbols

1 (1Y, 1M, 1C, 1B) photosensitive drum (image bearing member)
4 (4Y, 4M, 4C, 4B) Developing device 4a (4aY, 4aM, 4aC, 4aB) Developing roller (developer carrier)
5 (5Y, 5M, 5C, 5B) a developing blade (developer layer thickness regulating member)
6 (6Y, 6M, 6C, 6B) toner container (toner container)
8 (8Y, 8M, 8C, 8B) Process cartridge 10 (10a, 10Y, 10M, 10C, 10B) Pre-exposure device 12 (12Y, 12M, 12C, 12B) Exposure opening 13 (13Y, 13M, 13C, 13B) slit 14 before the exposure (14Y, 14M, 14C, 14B ) before the exposure hole 17 (17Y, 17M, 17C, 17B) charger 18 (18 Y, 18 M, 18 C, 18 B) a cleaning device 100 images Image forming apparatus main body 101 (101Y, 101M, 101C, 101B) Laser unit 201 (201Y, 201M, 201C, 201B) LED exposure unit 301 (301a, 301Y, 301M, 301C) Electrostatic latent image exposure apparatus T Intermediate transfer belt (intermediate transfer member)
Ta Conveyor belt (recording material carrier)
P Recording paper (recording material)

Claims (5)

Have a plurality of process cartridges for forming toner images of different colors is detachably mountable to an image forming apparatus main body, transferred onto a recording material carried to convey the toner image formed in the process cartridge by the recording material bearing member Or in an image forming apparatus that forms a color image by transferring to an intermediate transfer member,
Each of the plurality of process cartridges includes at least an image carrier on which a toner image is formed, a developing device that supplies toner to the image carrier, and a cleaning device that removes and collects residual toner from the image carrier. And
In the process cartridges arranged adjacent to each other, the process cartridges arranged on the downstream side in the moving direction of the recording material carrier or the intermediate transfer body are adjacent to the process cartridges located on the upstream side. An exposure device that acts on the image bearing member, and among the plurality of process cartridges, the process cartridge that is disposed on the most upstream side in the moving direction does not include the exposure device. An image forming apparatus. Of the plurality of process cartridges , an exposure device provided in the image forming apparatus main body acts on an image carrier of a process cartridge disposed at the most downstream side in the moving direction. The image forming apparatus according to claim 1.   The exposure device is a pre-exposure device for making the potential of the image carrier after the toner image is transferred to the recording material or the intermediate transfer member, or an electrostatic latent image is formed on the image carrier. The image forming apparatus according to claim 1, wherein the image forming apparatus is an electrostatic latent image exposure apparatus for forming, or is the pre-exposure apparatus and the electrostatic latent image exposure apparatus. Said recording material bearing member and the intermediate transfer member is a belt shape, and the plurality of process cartridges, it is arranged the belt-like before crisis Rokuzai carrier or in a row along the intermediate transfer body The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   5. The process cartridge according to claim 1, wherein among the plurality of process cartridges, the process cartridge disposed at the most upstream side in the moving direction forms a black toner image. The image forming apparatus described.

Images