JP3723199B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, and a printer. More specifically, the present invention relates to color image formation in which a plurality of developing devices are provided around an image carrier to form a developed image corresponding to an electrostatic latent image. The present invention relates to a technique for improving the handleability of an apparatus, particularly a developing apparatus.

JP 60-233668 A Japanese Patent Application Laid-Open No. 61-97674 Japanese Patent Publication No.4-223782 Japanese Utility Model Publication No. 4-38362 JP-A 63-78170 JP-A-4-29166 JP-A-60-208779 JP-A-60-214377 JP 61-73163 A JP-A-61-103175 Japanese Patent Publication No.59-26954 JP-A-60-233669 JP-A-62-85266 JP 62-102261 A Japanese Utility Model Publication No. 63-26847 JP-A-63-41871

  Conventionally, a color separation light image is exposed on an image carrier, each formed latent image is developed with a complementary color toner of color separation light, and a plurality of toner images obtained are superimposed and transferred onto the same transfer paper. Image forming apparatus such as a full-color copying machine, and images to be reproduced in different colors are separately exposed on an image carrier and developed with different color developers, and the resulting toner images are transferred to the same transfer paper. A multicolor image forming apparatus that transfers images superimposed on each other is known.

  These image forming apparatuses require a plurality of developing units. However, if each developing unit is configured independently and arranged in the vicinity of the image carrier, the apparatus becomes large.

  Therefore, a rotating body is provided so as to be close to the image bearing body, and a plurality of developing units are supported at a predetermined position of the rotating body, and each developing unit is sequentially rotated and conveyed to the developing area, thereby carrying the image bearing. 2. Description of the Related Art A rotary developing device using a one-component developer and a two-component developer that develops a latent image on a body with each color toner has been developed and put into practical use.

  In such an apparatus, when the image forming apparatus is actually used and maintained, it is necessary to replenish and replace toner and developer, perform maintenance and inspection of the unit, and replace the unit that has reached the end of its life. For this reason, methods, configurations, mechanisms and the like for performing these operations have been proposed.

  As a toner replenishment method, for example, as described in Patent Document 1 or Patent Document 2, a toner container, a cartridge, and the like are fixed to each developing device separately from each rotating developing device. Each developing device and each corresponding toner cartridge are connected by a flexible cylinder, and a toner conveying member made of a screw or the like provided in the cylinder is rotated so that each toner cartridge develops corresponding to it. A method for supplying toner to a container is known (conventional group 1).

  Also, a device called a developing cartridge or a developing magazine has been conventionally used in which a desired toner is contained in each developing device and the developing device is replaced when the toner in the developing device falls below a predetermined amount. Are known.

  Examples of replenishment and replacement of toner and developer, maintenance and inspection of units, etc., attaching and detaching and replacement of a developing device or a developing device include, for example, Patent Literature 3, Patent Literature 4, Patent Literature 5, and Patent Literature 6 A rotary type developing apparatus is described in which a plurality of developing units are integrally attached, detached, or replaced. Further, Patent Document 7, Patent Document 8, Patent Document 9, and Patent Document 10 disclose a rotary developing device in which a plurality of developing units attached to a support are separately attached and detached (conventional technology). Example group 2).

  In addition, the size of the image forming apparatus having a plurality of developing devices provided around the image carrier is reduced, and at the same time, the reliability of the black developing apparatus is improved, and the black and white image output frequently used is stabilized and increased. As an example of maintaining the quality, for example, as described in Patent Document 11, Patent Document 12, Patent Document 13, Patent Document 14, or Patent Document 15, Patent Document 16, etc. A black developer that forms a black image with a black developer, and a latent image formed on the photoreceptor by sequentially rotating to a development position different from the black developer, There has been proposed a color image forming apparatus in which a developing device in which a plurality of developing units for developing with a plurality of chromatic color (color) developers (toners) corresponding to a latent image are integrally disposed is disposed facing a photoreceptor. (Conventional group 3).

  However, the conventional example group 1 practically requires an intermediate connecting portion so as not to twist the flexible cylinder and the toner conveying member with respect to the rotating developing device. It is necessary to provide a shutter and a seal for preventing scattering, leakage, and mixing of other color toners, and there is a problem in cost due to a complicated configuration and an increase in the number of parts.

  By the way, a normal general document mainly outputs black and white images, and the ratio of black and white output images to color output images is also said to be, for example, 9: 1 to 7: 3. That is, among the plurality of development units, the frequency of use of the black development unit is considerably increased, and there is a difference in the degree of deterioration of functional parts such as toner consumption, developer and development roller. High reliability, high maintainability and exchangeability are demanded.

  However, in a conventional developing device 2 that does not have a toner replenishment or replenishment function, such as the rotary developing devices described in Patent Literature 3 and Patent Literature 6, for example, 1 It is necessary to replace the entire developing device when a color toner end occurs, and the developing device should be replaced even if other color toner remains sufficiently or the developing device itself still functions sufficiently. As a result, there was a lot of waste, which caused a significant increase in running costs.

  Further, the rotary developing device described in Patent Document 4 has a variation in the usage status of the device, and since the entire developing device is replaced when the toner in one developing chamber ends, there are many useless portions.

  In addition, the developing device described in Patent Document 5 requires cleaning, inspection, adjustment, repair, and replacement of the unit and each component. Further, in a device that uses a two-component developer, the developer (carrier) needs to be replaced periodically. It becomes.

  In addition, since the developing device described in Patent Document 5 carries a developing device equipped with a plurality of developing devices, the slider requires a complicated and strong configuration, which is costly and one developing device that is frequently used. When the device reaches the end of its service life, the entire device is also replaced. Therefore, as with the other conventional examples described above, there is a lot of waste, causing a significant increase in running cost.

  Further, in the rotary developing devices described in Patent Document 7, Patent Document 8, Patent Document 9, and Patent Document 10, etc., each developer has an independent side plate and casing, and further supports each unit. A support member is required, and there is a limit to the reduction in size and cost of the developing device. Further, since each developing device is handled one by one, it is necessary to frequently work, and when a plurality of developing devices are handled, there is a problem that extra work time is required.

  Of the conventional group 3, the devices described in Patent Document 11, Patent Document 12, Patent Document 13, Patent Document 14, or Patent Document 15, Patent Document 16, and the like are supplied with developer (toner) and developed. There is almost no description about the attachment and detachment of the vessel.

  Further, in the apparatus described in Patent Document 12, when the color developing device is replaced, each developing device is replaced in turn, and each developing device has an independent side plate and casing, and further supports each unit. A support member is required, and there is a limit to the reduction in size and cost of the developing device. In addition, when it is time to replace the developing devices at the same time as described above, it is necessary to work frequently because the developing devices are handled one by one, and when working with a plurality of developing devices, the work time is excessive. There was a problem.

  In view of the above-described problems, the present invention improves the handling and operability of black and color developing devices having different usage frequencies, and reduces the waste of the apparatus and supply, and is a small and inexpensive color. An object is to provide an image forming apparatus.

According to the present invention, the above-described problem is achieved by the image forming apparatus main body and the apparatus main body by a rotating shaft provided in the lower part of the apparatus main body so as to be exposed and extended downward from the upper front of the apparatus main body. A frame that is rotatably supported between a closed position and an open position that falls forward of the apparatus , and a belt body that is provided on the inner side of the frame and is stretched vertically by an upper roller and a lower roller, A cartridge that is pivotally supported at a retracted position, and is detachably attached to the apparatus main body inside the cartridge, is in contact with the belt body, and is disposed above and below, respectively. comprising at least including a plurality of units and a body, the said cartridge and said frame to rotate in the same direction, the closure position and the said frame cartridge And by turning from the working position, an opening for detachable said unit and the said frame cartridge is exposed front side of the apparatus in the open position and the retracted position from said apparatus main body front is formed This is solved by the image forming apparatus.

Further, according to the present invention, there is provided the image forming apparatus main body and the apparatus by a rotating shaft provided in the lower part of the apparatus main body so as to be exposed and extended downward from above the front surface of the apparatus main body. It includes a frame that is rotatably supported in a closed position relative to the main body and an open position that falls forward of the apparatus , and a belt body that is provided on the inner side of the frame and is stretched vertically by an upper roller and a lower roller. A cartridge rotatably supported at a position and a retracted position, and is detachable from the apparatus main body inside the cartridge, is in contact with the belt body, and is disposed above and below, respectively. agent comprises at least comprising a plurality of units and a carrier, rotates in the same direction as the cartridge and the frame integrally the said frame cartridge By turning from the closed position and the operating position, an opening for detachable said unit and the said frame cartridge device front side is exposed in the open position and the retracted position from said apparatus main body front This is solved by an image forming apparatus characterized in that is formed.

Further, according to the present invention, there is provided the image forming apparatus main body and the apparatus by a rotating shaft provided in the lower part of the apparatus main body so as to be exposed and extended downward from above the front surface of the apparatus main body. A frame that is pivotally supported in a closed position relative to the main body and an open position that falls forward of the apparatus , and is disposed on the back side of the frame and along the front surface of the apparatus, and is stretched vertically by an upper roller and a lower roller. A cartridge that is rotatably supported between an operating position and a retracted position, and is arranged in parallel vertically on the back side of the cartridge so as to face the belt body, and is detachable from the apparatus main body. A plurality of units each including at least a toner container and a developer carrying member, wherein the cartridge has an operating position where the belt body contacts the unit, and the belt body is in front. It provided rotatably in the open position spaced apart from the unit, and the cartridge and the frame rotates in the same direction, by rotating the frame and the cartridge from the closed position and the working position, the frame The image forming apparatus is characterized in that an opening is formed so that the unit is exposed from the front side of the apparatus main body and the unit is exposed at the open position and the retracted position. .

It is preferable that a waste toner container is mounted on the cartridge.
It is preferable that the waste toner container is detachable from the cartridge.
It is preferable that the cartridge is rotatably held via the subframe.
It is preferable that the cartridge is detachable from the subframe.

It is preferable that the pivot point of the frame is provided at the lower part of the apparatus main body.
It is preferable that the rotation fulcrum is provided on the front side of the apparatus.
It is preferable that the cartridge is configured to be rotatable integrally with the frame.

It is preferable that a sheet feeding unit is arranged at the lower part of the apparatus main body and a fixing device is arranged at the upper part, and the cartridge constitutes a part of a sheet conveyance path from the sheet feeding unit to the fixing device.
It is preferable that the paper conveyance path of the portion constituted by the cartridge is provided so as to be openable, and the paper conveyance path is opened to enable jam processing.

  According to the image forming apparatus of the present invention, since the opening for attaching / detaching the unit is formed only by rotating the frame and the cartridge, the attaching / detaching of the unit can be easily performed.

  If the cartridge is provided with a waste toner container and is detachable, waste toner can be easily processed.

  If the cartridge is rotatably held via the subframe and is detachably provided, the maintenance of the cartridge can be facilitated.

  By providing the pivot point of the frame on the front side of the lower part of the apparatus main body, maintenance inside the apparatus becomes easy.

  Since the cartridge is configured to be rotatable integrally with the frame, both of them can be rotated at a time.

The cartridge constitutes a part of the paper conveyance path, and the paper conveyance path of the part is provided so as to be openable, so that the jam processing can be easily performed.

  In the present invention, the first developing device for developing with the black developer is constituted by the developing cartridge, so that the developing cartridge can be replaced when the remaining amount of the developer becomes a predetermined amount or less. In addition, each developer unit for yellow (Y), magenta (M), and cyan (C) of the second developing device that develops with the color developer can be supplied with the developer individually.

Hereinafter, specific description will be given with reference to the accompanying drawings.
FIG. 1 is a configuration diagram of a color image forming apparatus showing an embodiment of the present invention.
The photosensitive belt 1 is installed between the rotating rollers 2 and 3 and is conveyed in the direction of arrow A (clockwise) in the figure by the rotational driving of the rotating roller 2. Around the photosensitive belt 1 as an image carrier, a color developing device 6 in which a charging charger 4, a laser optical device 5, and three developing units having yellow, magenta, and cyan color developers described later are integrally formed. The color developing device 6 is arranged separately from the black developing device 7 containing black developer and the rotating rollers 11 and 12, and is driven by the rotation of the rotating roller 11 in the direction of arrow B in the figure. A waste toner collecting container 15 including a cleaning blade 15a that always contacts the intermediate transfer belt 10 and the photosensitive belt 1 conveyed in the (counterclockwise) direction and cleans the toner on the photosensitive belt 1 is arranged in the order of processes. .

  The intermediate transfer belt 10 is in contact with the photosensitive belt 1 at the rotating roller 3 portion. On the intermediate transfer belt 10 side of the contact portion, a conductive bias brush 13 is provided so that the tip thereof contacts the back surface of the intermediate transfer belt 10 under a predetermined condition. The cleaning blade 16a of the cleaning device 16 for the intermediate transfer belt 10 is held at a position separated from the surface of the intermediate transfer belt 10 during the image forming operation, and the intermediate transfer belt 10 is transferred after the formed image is transferred onto the transfer paper 17a. It comes in contact with the surface.

  Also, a paper feed stand (paper feed cassette) 17 is disposed at the bottom of the apparatus, and the transfer paper 17a accommodated therein is transferred by a paper feed roller 18, transport rollers 19a and 19b, and registration rollers 20a and 20b. To be transported to.

  Next, the image forming operation will be described. The photosensitive belt 1 is uniformly charged by the charging charger 4 and then scanned and exposed by the laser optical device 5 based on the image information to form an electrostatic latent image on the surface. Here, the image information to be exposed is single-color image information obtained by separating a desired full-color image into yellow, magenta, cyan, and black color information, and a laser generated by a semiconductor laser (not shown) based on this information. The beam 5d is rotationally scanned by a polygon mirror 5b that rotates at high speed by a polygon motor 5a, passes through an fθ lens 5c, and is adjusted in optical path by a reflection mirror 5e.

  The electrostatic latent image formed here is developed in a single color with predetermined yellow, magenta, and cyan toners, respectively, by a rotary color developing device 6 described later. Further, the latent image based on the black color information is developed with black toner by a black developing unit 7 described later, and each color image is sequentially formed on the photosensitive belt 1.

  Each single-color image formed on the photosensitive belt 1 rotating in the direction of arrow A in the drawing is yellow, magenta, and yellow on the intermediate transfer belt 10 rotating in the direction of arrow B in the drawing in synchronization with the photosensitive belt 1. For each single color of cyan and black, the images are sequentially superimposed and transferred by a predetermined transfer bias applied to the bias brush 13. The yellow, magenta, cyan, and black images superimposed on the intermediate transfer belt 10 were conveyed from the sheet feeding table 17 to the transfer unit via the sheet feeding roller 18, the conveying rollers 19a and 19b, and the registration rollers 20a and 20b. The images are collectively transferred onto the transfer paper 17a by the transfer roller 14.

  After the transfer is completed, the transfer paper 17a is fixed by the fixing device 50 to complete a full-color image, and the print image is discharged to the paper discharge stack unit 52 through the paper discharge rollers 51a and 51b.

  Waste toner scraped off from the intermediate transfer belt 10 by the cleaning blade 16a is transported vertically upward (toward the front of the apparatus) by the auger 16b provided in the cleaning device 16, and further, the front side of the process cartridge 31 The toner is transported to the waste toner collecting container 15 by a transport unit (not shown).

  By replacing the process cartridge 31 when a predetermined amount or more of the waste toner is accommodated in the waste toner collecting container 15, the life of the process cartridge 31 can be extended.

  Further, the photosensitive belt 1, the charging charger 4, the intermediate transfer belt 10, the cleaning device 16, and the registration roller 20 b are integrally configured as a process cartridge 31, and the waste toner collection container 15 can be replaced with the process cartridge 31. Incorporated into. The case exterior portion on the registration roller 20b side of the process cartridge 31 also has a function as a paper transport guide.

FIG. 2 is a block diagram of the black developing device.
As shown in FIG. 2, the black developing device 7 contains a black developer (toner) in a developing container 41, and an opening 41 a of the container 41 facing the photosensitive belt 1 serves as a developer carrying member. The developing device is integrally formed as a so-called developing cartridge having the developing roller 23K.

  The developing container 41 is slid in the direction opposite to the surface movement direction of the developing roller 23K at the contact portion of the developing roller 23K while being in parallel with the developing roller 23K and in contact with the developing roller 23K with a predetermined contact pressure and forming a nip. A toner supply roller 25K that is rotated, for example, made of foamed polyurethane or the like is disposed.

  Toner made of a thin plate having a spring property such as stainless steel or an elastic material such as urethane rubber in the vicinity of the opening 41a on the downstream side in the moving direction of the developing roller 23K from the sliding portion between the supply roller 25K and the developing roller 23K. A blade 26K as a layer regulating member is provided such that the vicinity of one end thereof is in contact with the developing roller 23K.

  Further, the developing container 41 has a plurality of blade-like portions, the axial direction of which is arranged in parallel with the axial direction of the supply roller 25K, agitates the toner in the vicinity of the supply roller 25K, and the toner on the surface of the supply roller 25K. A stirring paddle 42 that rotates in the direction of arrow C in the drawing is provided so that toner regulated by the blade 26K is not deposited and packed in a portion surrounded by the developing roller 23K, the blade 26K, and the supply roller 25K. Is provided.

  Further, in the developing container 41, the toner in the container 41 is agitated and the toner in the container 41 is also agitated, and the first agitator 43 that conveys the toner to the supply roller 25K and the developing roller 23K side. A second agitator 44 that conveys toner to the 25K and developing roller 23K side is disposed in parallel with the developing roller 23K and the supply roller 25K.

  Both the first and second agitators 43 and 44 are attached with a film-like elastic sheet or the like at the tip thereof so that the tip slides and moves on the bottom of the container 41, so that the toner in the container 41 is efficiently collected. The toner can be transported and the remaining amount of toner in the container 41 can be reduced. It is desirable that the rotational speeds of the agitators 43 and 44 be as low as possible so as not to apply excessive stress to the toner.

FIG. 3 is a configuration diagram showing a state when the color developing device and the black developing device are not operated.
Normally, as shown in FIG. 3, the black developing device 7 is retracted to a position where the developing roller 23 </ b> K does not come into contact with the surface of the opposing photosensitive belt 1. When developing the black latent image formed on the photoreceptor belt 1, the entire black developing device 7 is moved horizontally along a guide member (not shown) by the action of the cam 45, and the developing roller 23K is exposed to light. The surface of the body belt 1 is brought into contact with a predetermined nip.

  When the developing roller 23K is not in contact with the photosensitive belt 1, the driving of the developing roller 23K is turned off and the developing roller 23K is controlled not to rotate so that the toner scatters from the opening 41a of the black developing device 7. Leakage and early deterioration of the developing roller 23K and other components of the black developing device 7 are prevented.

FIG. 4 is an enlarged configuration diagram of the color developing device and the black developing device.
In the vicinity of the photoreceptor belt 1, a rotary type (also referred to as a revolver type or rotary type) color developing device 6 as a developing device according to the present invention is disposed.

  FIG. 4 shows a state where one developing device 22Y is at the developing position. Each of the developing units 22Y, 22M, and 22C is provided with cylindrical developing rollers 23Y, 23M, and 23C as developer conveying members. Each of the developing rollers 23Y, 23M, and 23C is arranged so that a part of the developing roller 23Y, 23M, and 23C is exposed to the outside from the opening 21a provided in the casing 21, and is synchronized with the color information by a drive mechanism that is not illustrated. Rotate in the direction of arrow D to develop the corresponding electrostatic latent image. At this time, in the black developing device 7, the developing roller 23K is held at a position separated from the surface of the photosensitive belt 1 by a cam 45 and a spring (not shown).

  The color developing device 6 of the present embodiment uses a non-magnetic one-component developer, and each of the developing units 22Y, 22M, and 22C stores yellow, magenta, and cyan toners, and is selectively selected around the rotation center O. Then, the electrostatic latent images formed on the photosensitive belt 1 are sequentially developed as described above.

FIG. 5 is a configuration diagram of a yellow developing device.
Since the color developing units 22Y, 22M, and 22C have the same form and the same operation, only the developing unit 22Y will be described here.

  In FIG. 5, the developing unit 22Y is disposed below the photosensitive belt 1 side, and toner as a nonmagnetic one-component developer is formed on the electrostatic latent image formed on the photosensitive belt 1 positioned above the developing unit 22Y. Supply.

  An opening 21a is formed above the developing unit 22Y. The developing roller 23Y is disposed in the opening 21a so as to face the photoreceptor belt 1 so as to rotate in the same direction as the movement direction of the photoreceptor belt 1 with a predetermined peripheral speed ratio with the photoreceptor 1. Below the developing roller 23Y, a supply roller 25Y as a toner supply member made of an elastic material such as foamed polyurethane slides on the developing roller 23Y, and at a rubbing portion with a predetermined peripheral speed ratio with respect to the developing roller 23Y. It is provided to rotate in the same direction as the developing roller 23Y.

  A blade made of a thin plate having a spring property such as stainless steel or an elastic body such as urethane rubber, in the vicinity of the opening 21a on the downstream side in the moving direction of the developing roller 23Y from the sliding portion between the supply roller 25Y and the developing roller 23Y. 26Y is provided such that the vicinity of one end thereof is in contact with the developing roller 23Y.

  In the figure, reference numeral 27Y denotes a screw-like first toner conveying member, which will be described later, and conveys the toner from the front side to the back side in the drawing.

FIG. 6 is a front sectional view of the developing device for yellow, and FIG. 7 is a perspective view of the main part of the color developing device.
As shown in FIGS. 6 and 7, a toner storage unit 29Y is provided on the front side of the developing unit 22Y. The first toner conveying member 27Y is disposed in parallel with the developing roller 23Y and the supply roller 25Y from the toner containing portion 29Y to the other side plate of the developing device 22Y. The casing 21Y is disposed so that a part thereof is in contact with the supply roller 25Y, and the toner transfer space 24Y surrounding the first toner transfer member 27Y by the developing roller 23Y, the supply roller 25Y, and the casing 21Y (see FIG. 5). ) Is formed.

  The first toner conveying member 27Y rotates with a predetermined peripheral speed ratio in conjunction with the developing roller 23Y and the supply roller 25Y so as to convey the toner from the front side to the rear side in FIGS. . By this rotation, the first toner conveying member 27Y conveys the toner from the toner containing portion 29Y into the toner conveying space 24Y and supplies the toner onto the supply roller 25Y.

  The toner supplied onto the supply roller 25Y is supplied while being charged on the surface of the developing roller 23Y by the supply roller 25Y, and is carried on the surface of the developing roller 23Y. The toner carried on the surface of the developing roller 23Y is formed into a uniform and thin toner layer by the blade 26Y, and the electrostatic latent image formed on the surface of the photoreceptor belt 1 is developed by contact or non-contact development.

  Incidentally, as shown in FIG. 6, the toner that has not been used in the developing step is transported by the first toner transport member 27Y to the end of the developing device on the side opposite to the toner containing portion 29Y. A toner circulation portion 32Y is provided outside the effective diameter portion in the axial direction of the developing roller 23Y and the supply roller 25Y. The toner transported to the toner circulation section 32Y by the first toner transport member 27Y falls to the lower portion of the developing device 22Y due to gravity.

  Below the developing unit 22Y, a screw-like second toner conveying member 28Y is also arranged in parallel with the developing roller 23Y, the supply roller 25Y, and the first toner conveying member 27Y, and the first toner conveying member 27Y and Is rotated so as to convey the toner in the opposite direction, and the toner that has not been used in the developing process is conveyed to the toner containing portion 29Y.

  By appropriately setting the conveyance amounts of the first toner conveyance member 27Y and the second toner conveyance member 28Y, the supply roller 25Y can be detected without detecting the amount of toner in the developing device 22Y or performing complicated supply amount control. It is possible to provide a small-sized developing device that can be supplied above, has a high degree of freedom in layout, and has a small cross-sectional occupation ratio with respect to the photosensitive belt 1.

  In FIG. 7, reference numeral 30 (30Y, 30M, 30C) denotes a toner cartridge that is detachably attached to the toner container 29, and is attached and replaced when the color developing device 6 is newly installed and when the toner end is reached. A necessary amount of toner is always stored in the toner storage unit 29.

  Except during the image forming operation, as shown in FIG. 3, in the black developing device 7, the developing roller 23K is held at a position separated from the surface of the photosensitive belt 1 by a cam 45 and a spring (not shown). The Further, the color developing device 6 stands by and stops at a developing device home position as shown in FIG. 3 at times other than during the image forming operation, that is, before and after the image forming operation.

  In the present embodiment, a position where the rollers 23Y and 23C do not contact the surface of the photoreceptor belt 1 at a substantially intermediate point between the developing roller 23Y of the yellow developing device 22Y and the developing roller 23C of the cyan developing device 22C. The home position. This is because when the color developing operation is performed in the present embodiment, the yellow developing device 22Y used first is rotated by the color developing device 6 in the direction of the arrow D in the figure at the time of image formation. It is a position that can reach the developing position quickly and accurately, and prevents the photoreceptor 1 and the developing roller 23 from being deteriorated or damaged due to unnecessary contact between the photoreceptor belt 1 and the developing roller 23 when not in operation. This is a position that prevents toner from adhering to or sticking out of the area.

FIG. 8 is a block diagram showing a state in which the front frame 8 of the color image forming apparatus shown in FIG. 1 is opened, and FIG. 9 is a block diagram showing how the toner cartridge is replaced.
The configuration relating to the image forming apparatus main body will be described with reference to FIGS. The apparatus main body structure is composed of a main body frame 9 that is a stationary housing and a front frame 8 that is a front housing that can open the transfer path of the transfer paper 17a. 17, the color developing device 6, the black developing device 7, and the process cartridge 31 are replaceably disposed inside the main body, and the fixing device 50 is further disposed above the color developing device 6, and the discharge stack unit 52 is disposed above the main body. Is formed.

  The front frame 8 is supported so as to be capable of opening and closing about a rotation support shaft 9a provided on the main body frame 9, and is normally held in a closed state with respect to the main body frame 9 as shown in FIG. When the transfer paper 17a is jammed in the transfer path of the transfer paper 17a, the locking mechanism of the front frame 8 (not shown) is released and the front frame 8 is opened as shown in FIG. The front frame 8 holds a transfer roller 19a, a registration roller 20a, a transfer roller 14, and the like that constitute a part of the transfer paper transport path. By opening the front frame 8, the transfer paper transport path is exposed. Jam can be handled easily. At this time, the other image forming units are stationary, and no troubles due to toner scattering or leakage occur.

  Further, for example, when the amount of yellow toner becomes a predetermined amount or less, the toner end is detected by a conventionally known toner end detection means or the like, and a toner replacement display is made. In this case, as shown in FIG. 9, the toner cartridge 30Y is replaced with the front frame 8 opened.

FIG. 10 is a block diagram showing how the black developing device is replaced.
As described above, the black developing device 7 as the first developing device of the present invention is formed as a so-called developing cartridge (DTM). When the amount of toner in the black developing device 7 becomes less than a predetermined amount due to its use, the toner end is detected by a toner amount detecting means using an optical sensor, a magnetic sensor, a piezoelectric element, or the like, which is not shown in the drawings. Is detected, and a unit replacement signature is displayed on the display panel, for example.

  A subframe (not shown) is attached to the rotary shaft 9a of the front frame 8 so as to be rotatable about the rotary shaft 9a, and the process cartridge 31 is detachably held on the subframe. When the black developing device 7 is replaced, the sub-frame is rotated around the rotation shaft 9a simultaneously with the front frame 8, and the process cartridge 31 is opened in the same manner as the front frame 8, as shown in FIG. As a result, a device opening for attaching and detaching the developing device appears, and the black developing device 7 can be easily replaced without temporarily moving the process cartridge 31 out of the image forming apparatus main body.

  FIG. 11 is a block diagram showing a state in which the black developing device and the color developing device are replaced as a unit. FIG. 12 is a perspective view showing a state in which the black developing device and the color developing device are incorporated in the frame.

The attachment / detachment and replacement of the color developing device 6 will be described with reference to these drawings.
In normal full-color image formation, although the toner consumption varies depending on the color, the usage amounts of the yellow, magenta, and cyan three developing devices are the same. The black developing device 7 is replaced with, for example, several thousand sheets because of the capacity of the container, but the color developing device 6 is reduced in replacement work frequency, improved operability, and substantial cost reduction due to long-term use of the unit. For this reason, for example, the yellow, magenta, and cyan three developing devices are replaced with each other by counting the predetermined usage amount of tens of thousands of sheets.

  When the count value of the usage amount of the color developing device 6 stored in the internal memory or the like of the image forming apparatus main body reaches a predetermined value, the lifetime of the unit is displayed on the display panel, for example. Thereafter, when the toner end of the black developing device 7 is detected, a simultaneous replacement sign of the black developing device 7 and the color developing device 6 is displayed on, for example, a display panel. With this sign, the operator rotates the sub-frame around the rotation shaft 9a simultaneously with the front frame 8 in the same manner as when the black developing device 7 is replaced, and the process cartridge 31 is moved as shown in FIG. Open in the same manner as the front frame 8.

  As shown in FIGS. 11 and 12, the color developing device 6 is supported so as to be rotatable around the rotation center O with respect to the frame 33. The black developing device 7 is also detachably supported with respect to the frame 33, and the black developing device 7 is removed by taking out the frame 33 from the opening of the image forming apparatus main body for attaching and detaching the developing device by the handle 33a of the frame 33. The color developing device 6 is detached from the main body of the image forming apparatus with a single work operation. In addition, when the black developing device 7 and the color developing device 6 are mounted on the image forming apparatus main body, the work operation is performed once by mounting the frame 33 by the grip portion 33a of the frame 33, as described above. become.

1 is a configuration diagram of a color image forming apparatus showing an embodiment of the present invention. It is a block diagram of a black developing device. It is a block diagram showing a state when the color developing device and the black developing device are not operating. It is an enlarged block diagram of a color developing device and a black developing device. It is a block diagram of the developing device for yellow. FIG. 3 is a front sectional view of a yellow developing device. It is a perspective view of the principal part of a color developing device. FIG. 2 is a configuration diagram of a state in which a front frame of the color image forming apparatus illustrated in FIG. 1 is opened. FIG. 3 is a configuration diagram showing how a toner cartridge is replaced. FIG. 6 is a configuration diagram showing how the black developing device is replaced. FIG. 3 is a configuration diagram showing a state in which a black developing device and a color developing device are replaced as a unit. FIG. 3 is a perspective view of a state in which a black developing device and a color developing device are incorporated in a frame.

Explanation of symbols

1 Photoreceptor belt (image carrier)
6 Color developing device (second developing device)
7 Black developer (first developer)

Claims (3)

An image forming apparatus main body;
Extending downward from the upper front of the device main body and exposed, it can be rotated to a closed position with respect to the device main body and an open position where the device falls forward by a rotating shaft provided at the lower part of the device main body. A frame supported by
A cartridge provided inside the frame, including a belt body stretched vertically by an upper roller and a lower roller, and rotatably supported between an operating position and a retracted position;
A plurality of units which are detachably attached to the apparatus main body inside the cartridge, are in contact with the belt body and are disposed above and below each other, and each include at least a toner accommodating portion and a developer carrier;
The said cartridge and said frame to rotate in the same direction,
By rotating the frame and the cartridge from the closed position and the operating position, the unit in which the front side of the apparatus is exposed at the open position and the retracted position of the frame and the cartridge is removed from the front surface of the apparatus main body. An image forming apparatus, characterized in that an opening for making it detachable is formed. An image forming apparatus main body;
Extending downward from the upper front of the device main body and exposed, it can be rotated to a closed position with respect to the device main body and an open position where the device falls forward by a rotating shaft provided at the lower part of the device main body. A frame supported by
A cartridge provided inside the frame, including a belt body stretched vertically by an upper roller and a lower roller, and rotatably supported between an operating position and a retracted position;
A plurality of units which are detachably attached to the apparatus main body inside the cartridge, are in contact with the belt body and are disposed above and below each other, and each include at least a toner accommodating portion and a developer carrier;
The said cartridge and said frame to rotate in the same direction,
By rotating the frame and the cartridge integrally from the closed position and the operating position, the unit and the main body of which the front side of the apparatus is exposed at the open position and the retracted position of the frame and the cartridge. An image forming apparatus, wherein an opening is formed to be detachable from a front surface . An image forming apparatus main body;
Extending downward from the upper front of the device main body and exposed, it can be rotated to a closed position with respect to the device main body and an open position where the device falls forward by a rotating shaft provided at the lower part of the device main body. A frame supported by
A cartridge that is disposed along the front side of the frame and along the front surface of the frame, includes a belt body that is vertically extended by an upper roller and a lower roller, and is supported rotatably at an operating position and a retracted position;
A plurality of units that are arranged side by side in the vertical direction facing the belt body at the back side of the cartridge, are detachable from the apparatus main body, and each include at least a toner storage portion and a developer carrier,
The cartridge is rotatably provided at an operation position where the belt body contacts the unit and an open position where the belt body is separated from the unit,
The said cartridge and said frame to rotate in the same direction,
By rotating the frame and the cartridge from the closed position and the operating position, the frame and the cartridge are attached to and detached from the front surface of the apparatus main body with the frame and the cartridge exposed from the front side of the apparatus at the open position and the retracted position. An image forming apparatus, characterized in that an opening is formed for enabling .

Images