JP5533580B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus provided with a special toner consumable that can be easily replaced by a user without the need for cleaning before use or after use.

  Conventionally, there is an electrophotographic image forming apparatus. In this image forming apparatus, generally, a photosensitive drum is uniformly charged and initialized, an electrostatic latent image is formed on the photosensitive drum by optical writing, and the electrostatic latent image is converted into a toner image. Is directly or indirectly transferred onto a transfer material such as paper and fixed by a fixing device.

  Such electrophotographic image forming apparatuses include those using a one-component developer composed only of toner and those using a two-component developer composed of toner and carrier. In recent years, a method using a two-component developer can cope better with the demand for high-speed printing (hereinafter also referred to as printing) processing.

  The carrier of the above two-component developer is mixed and agitated with the toner in the developing device to give the toner a predetermined charge. The charged toner temporarily adheres to the surface of the carrier and coats the surface of the carrier.

  The carrier attached to the magnetic developing roller carries the charged toner onto the photosensitive member, transfers the toner to the electrostatic latent image on the photosensitive member, and develops the toner image on the electrostatic latent image.

  The carrier from which the toner on the surface has been released remains on the developing roller, returns to the inside of the developing device, and is mixed and stirred again with new toner to be replenished to the developing device. It is used repeatedly, such as carrying.

  To replenish toner to the developing device, there are a method of replenishing only the toner and a method of replenishing a developer composed of a mixed powder of toner and carrier called trickle development. Hereinafter, a case where only toner is replenished will be described for the sake of simplicity.

  With regard to such replenishment of toner to the developing device, the toner cartridge that can be attached to and detached from the image forming apparatus main body can be replaced with a reserve tank so that the toner cartridge can be replaced without stopping the operation of the image forming apparatus main body. An apparatus for supplying toner and conveying the toner from the reserve tank to the toner developing container has been proposed. (For example, refer to Patent Document 1.)

  In addition, the development unit of the tandem color image forming apparatus includes a variable capacity reserve tank in addition to the toner cartridge, and the toner cartridge can be replaced after the toner in the toner cartridge is completely used up. An image forming apparatus capable of exchanging a toner cartridge even during printing has been proposed (see, for example, Patent Document 2).

  By the way, there is a demand for printing with fluorescent toner or rewritable toner (toner that can erase printing when a printed document is no longer needed) using such a commonly used image forming apparatus.

  However, when printing is performed by changing the type of toner, it is necessary to replace or clean all of the toner supply path, that is, all of the toner cartridge, the reserve tank, the toner supply path, etc., together with the developing device.

  However, the reserve tank and the toner supply path are usually devices fixed to the image forming apparatus main body frame. In addition, in order to facilitate the attachment and detachment of the toner cartridge and the developing device, the toner supply path is usually arranged so as to wrap around the reserve tank and the transfer unit which is also fixedly arranged on the apparatus main body frame. In addition, toner is contained inside.

  Therefore, in order to replace or clean the entire toner replenishment path with the developing unit, it is necessary to perform almost the same work as disassembling the image forming apparatus main body before that. There is a problem to be solved that this work is a work that can be performed only by an engineer specializing in maintenance, and is not a work that can be easily performed by the user.

JP 2003-029518 A JP 2008-276034 A

  The present invention solves the above-described conventional problems, and provides an image forming apparatus provided with a special toner consumable that can be easily replaced by a user, without the need for cleaning before and after use. Objective.

To solve the above SL is provided an image forming apparatus of the present invention, a plurality of developer containers to replenish the respective developer to the plurality of developing devices and the plurality of developing devices that are arranged side by side at the tandem method is more An image forming apparatus that is spaced apart via a developer replenishment path, and is disposed at each end of the plurality of developer replenishment paths connected to the plurality of development apparatuses from the plurality of developer containers. A pre-development device that performs development with a special toner that is different from the normal toner used by the plurality of development devices for development, and a pre-replenishment device that replenishes the pre-development device with the special toner, When developing with the special toner, the shutters of the two developer supply paths connected to two adjacent developing devices of the plurality of developing devices are closed, and the two developing devices are closed. Equipment and the above two The connection with the developer replenishment path is disconnected, the two developing devices are removed from the first or second arrangement position, which is the respective arrangement position, and the first arrangement in which the two developing devices are removed. The preliminary developing device is disposed at a set position, the preliminary replenishing device is disposed at the second disposing position where the two developing devices are removed, the preliminary developing device and the preliminary replenishing device are connected, While the special toner is supplied to the preliminary developing device by the preliminary replenishing device, the preliminary developing device performs the development with the special toner.

In the image forming apparatus of the present invention, the special toner is, for example, a fluorescent toner or a rewritable toner. The developer is, for example, a one-component toner or a two-component developer.

  According to the present invention, it is possible to provide an image forming apparatus provided with a special toner consumable that does not require a process such as cleaning before use or after use, and that can be easily replaced by a user.

1 is a cross-sectional view illustrating an internal configuration of a full-color image forming apparatus (printer) according to Embodiment 1 of the invention. (a) is a diagram schematically showing a developing device of an image forming unit and a reserve tank and a toner cartridge of a toner supply unit of the printer according to the first embodiment, with only one each being easily understood and schematically shown together with a transfer belt. It is sectional drawing which looked at from the side. FIG. 2 is an enlarged view of a developing device of an image forming unit and a reserve tank and a toner cartridge of a toner supply unit of a printer according to a first embodiment together with a transfer belt. FIG. 3 is a diagram illustrating a usage mode when printing is performed using special toner by the printer according to the first exemplary embodiment. FIG. 10 is a diagram (part 1) illustrating another usage mode in the case where printing is performed using special toner by the printer according to the second embodiment. FIG. 10 is a diagram (part 2) illustrating another usage mode when printing is performed using special toner by the printer according to the second embodiment. (a), (b) are two examples in which the internal configuration differs in a state where the preliminary developing device and the preliminary replenishing device are connected when printing is performed using special toner by the printer according to the second embodiment. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, a two-component developer including a toner and a carrier is used. In the following description, the two-component developer is simply referred to as a developer or a toner.

  FIG. 1 is a cross-sectional view illustrating an internal configuration of a full-color image forming apparatus (hereinafter simply referred to as a printer) according to Embodiment 1 of the present invention.

  A printer 1 shown in FIG. 1 is an electrophotographic secondary transfer tandem color image forming apparatus, and includes an image forming unit 2, a transfer belt unit 3, a toner supply unit 4, a paper feeding unit 5, and a belt type fixing device. It comprises a unit 6 and a transport unit 7 for duplex printing.

  The image forming unit 2 is in contact with the lower running unit surface 8a of the transfer belt 8 of the transfer belt unit 3 and multi-stages four developing devices 9 (9k, 9c, 9m, 9y) from right to left in FIG. It consists of a side-by-side configuration. The image forming unit 2 is held by a frame of the printer 1 main body so as to be movable up and down from a printing execution position shown in FIG. 1 to a maintenance position below it.

  Of the four developing devices 9, three developing devices 9c, 9m, and 9y on the upstream side (the left side in the figure) are cyan (C), magenta (M), and yellow (Y), which are subtractive three primary colors, respectively. A mono-color image is formed with the color toner, and the developing device 9k forms a monochrome image mainly with black (K) toner used for characters and dark portions of the image.

  Each of the developing devices 9 has the same configuration except for the color of the toner that develops the image. Therefore, the configuration of the developing device 9y for yellow (Y) toner will be described below as an example.

  The developing device 9 includes a photosensitive drum 10 at the top. The photosensitive drum 10 has a peripheral surface made of, for example, an organic photoconductive material. A cleaner 11, a charging roller 12, an optical writing head 13, and a developing roller 15 of the developing device 14 are disposed around the periphery of the photosensitive drum 10.

  The developing device 14 includes a housing 16 that covers the outside, a partition wall 17 provided inside, a developing roller 15, a first stirring and conveying screw 18, and a second stirring and conveying screw 19. As will be described later, the first and second agitating and conveying screws 18 and 19 include a screw shaft and a fin that is integrally formed with the screw shaft and rotates.

  The developing unit 14 includes a reserve tank 27 (27k, 27c, 27m, 27y), which will be described in detail later, in the toner supply unit 4, and black (K), as indicated by K, C, M, Y in FIG. Either cyan (C), magenta (M), or yellow (Y) toner is supplied.

  The transfer belt unit 3 has an endless transfer belt 8 that extends in the shape of a flat loop in the left-right direction in the figure at approximately the center of the main unit, and the transfer belt 8 is stretched over the transfer belt 8. A driving roller 21 and a driven roller 22 are provided to circulate and move counterclockwise as indicated by an arrow a in the figure.

  The transfer belt 8 includes a primary transfer roller 20 that is integrated with the unit. The primary transfer roller 20 is pressed against the photosensitive drum 10 via the transfer belt 8 and directly transfers (primary transfer) the toner image to the belt surface that circulates below. The transfer belt 8 conveys the toner image to the secondary transfer unit 23 to the paper for further transfer (secondary transfer) to the paper.

  A belt cleaner 24 is disposed in the transfer belt unit 3. The belt cleaner 24 includes a cleaning blade 25 that comes into contact with the surface of the transfer belt 8 that is stretched over the drive roller 21. A waste toner collecting container 26 is detachably disposed below the belt cleaner 24.

  The belt cleaner 24 scrapes and removes the waste toner remaining on the surface of the transfer belt 8 by the cleaning blade 25, and sends the waste toner to the waste toner collection container 26 below by a conveying screw.

  The toner supply unit 4 includes four reserve tanks 27 (27k, 27c, 27m, and 27y) that are disposed above the upper running unit of the transfer belt 8 and are detachably disposed on the reserve tanks 27, respectively. Toner cartridge 28 (28k, 28c, 28m, 28y) for toner replenishment.

  The four toner cartridges 28k, 28c, 28m, and 28y accommodate black (K), cyan (C), magenta (M), and yellow (Y) toners, respectively, and four reserve tanks 27 (27k, 27c). , 27m, 27y) are replenished with toner from the toner cartridge 28 mounted thereon.

  These four reserve tanks 27 are hidden behind the opposite side of the transfer belt unit 3 in FIG. 1, but are connected to the corresponding developing devices 14 of the developing device 9 by toner supply paths.

  Although not particularly shown, the toner supply unit 4 is held on the frame of the printer 1 main body so as to be able to be raised and lowered from the printing execution position shown in FIG. 1 to a maintenance position above it.

  Two electrical parts 30 are disposed on the left side of the toner supply unit 4 from the left side of the belt cleaner 24 to above the drive roller 21. The electrical unit 30 includes a circuit board on which a control device including a plurality of electronic components is mounted.

  The paper feed unit 5 includes two paper feed cassettes 29 (29a, 29b) arranged in two upper and lower stages. A paper take-out roller 31, a feed roller 32, a separating roller 33, and a standby conveyance roller pair 34 are disposed in the vicinity of the paper feed opening (right side of the drawing) of the two paper feed cassettes 29, respectively.

  A secondary transfer roller 35 that is in pressure contact with the driven roller 22 via the transfer belt 8 is disposed in the paper transport direction (vertically upward in the drawing) of the standby transport roller pair 34, and the secondary transfer onto the paper described above. Part 23 is formed.

  A belt-type heat fixing unit 6 is disposed downstream (upward in the drawing) of the secondary transfer portion. On the further downstream side of the belt-type heat fixing unit 6, a pair of carry-out rollers 36 for carrying out the fixed paper from the belt-type heat fixing unit 6, and a paper discharge tray 37 formed on the upper surface of the apparatus. A paper discharge roller pair 38 for paper discharge is provided.

  The conveyance unit 7 for double-sided printing also serves as an opening / closing member whose outer surface (right outer surface in the drawing) opens or shields the inside of the printer 1 from the side surface to the outside.

  This duplex printing transport unit 7 has a start return path 39a that branches rightward in the figure from just before the paper discharge roller pair 38, an intermediate return path 39b that bends downward, and a left lateral direction opposite to the above. Thus, a return path 39 including a terminal return path 39c for finally inverting the return sheet is provided.

  In the middle of the return path 39, five pairs of return rollers 41 (41a, 41b, 41c, 41d, 41e) are arranged. The exit of the end return path 39 c joins the conveyance path to the pair of standby conveyance rollers 34 corresponding to the sheet feeding cassette 29 b below the sheet feeding unit 5.

  FIG. 2A schematically shows the developing device 9 of the image forming unit 2 of the printer 1 and the reserve tank 27 and the toner cartridge 28 of the toner supply unit 4 in an easy-to-understand manner together with the transfer belt 8. FIG. 2B is a cross-sectional view of these viewed from the side.

  2 (a) and 2 (b), the same components or functions as those shown in FIG. 1 are given the same reference numerals as in FIG. In FIG. 2B, the transfer belt unit 3 is indicated by a broken line block in place of the transfer belt 8 of FIG.

  The toner cartridge 28 shown in FIGS. 2 (a) and 2 (b) is placed in the reserve tank 27 in the front direction with respect to the main body of the image forming apparatus 1 shown in FIG. 1, that is, as indicated by the double arrow b in FIG. On the other hand, it is detachable.

  As shown in FIG. 2B, the toner cartridge 28 is provided with a detected part 42 that indicates whether the toner cartridge 28 is new or old, and a detection part that detects whether the toner cartridge 28 is new or old on the main body side of the printer 1. 43 is arranged. The detecting device 44 including the detected portion 42 and the detecting portion 43 for detecting whether the toner cartridge 28 is new or old can be configured by a very general and inexpensive method.

  The toner cartridge 28 includes a toner replenishing mechanism 47 including a rotating shaft 45 and a helical stirring fin 46 inside. A cartridge motor 48 is engaged with the rotation shaft 45 of the toner supply mechanism 47 from the outside.

  Further, the toner cartridge 28 is connected to the reserve tank 27 at the end opposite to the side engaged with the cartridge motor 48, and is connected to the reserve tank 27 to replenish the reserve tank 27 with the toner 49. A toner replenishing port 51 is formed.

  The toner replenishing mechanism 47 extends along the longitudinal direction of the toner cartridge 28 from the right end portion to the left end portion of the toner cartridge 28, and forms a fin-shaped change point 52 immediately above the toner replenishing port 51. The toner 49 is sent out to the toner replenishing port 51.

  An empty toner amount detection sensor 53 is disposed in the toner cartridge 28 at a position close to the fin-shaped change point 52 on the toner replenishing port 51. The output signal line of the toner amount empty detection sensor 53 is automatically connected to a sensor unit of a control device (not shown) when the toner cartridge 28 is attached to the reserve tank 27.

  Inside one of the reserve tanks 27, a toner replenishing mechanism 56 comprising a rotating shaft 54 and a helical stirring fin 55, which is the same as the toner cartridge 28, is disposed. A reserve tank motor 57 is engaged with the rotating shaft 54 of the toner supply mechanism 56 from the outside.

  The toner replenishing mechanism 56 extends along the longitudinal direction of the reserve tank 27 from the left end portion to the right end portion of the reserve tank 27, and the toner 49 replenished from the toner cartridge 28 via the toner replenishment port 51 at the left end portion. To the right end.

  A fin-shaped change point 58 of the toner replenishing mechanism 56 is formed at the right end. Immediately below the fin-shaped change point 58, an upper end portion of a toner supply path 59 serving as a developer supply path connecting the reserve tank 27 and the developing device 14 is opened.

  The toner replenishment path 59 is arranged so as to wrap around the back of the transfer belt unit 3. A shutter 61 is disposed at the lower end of the toner supply path 59 connected to the developing device 14.

  The shutter 61 is opened by a shutter opening / closing drive unit of a control device (not shown) in synchronization with the toner supply operation of the toner supply mechanism 56 of the reserve tank 27, and in synchronization with the toner supply operation of the toner supply mechanism 56 being stopped. Control is performed to close the shutter.

  In the toner replenishing operation by the toner replenishing mechanism 56, the toner 49 stirred and conveyed by the stirring fin 55 up to the fin shape change point 58 falls from the top to the bottom of the toner replenishing path 59 by the weight of the toner 49.

  As a result, the toner 49 is supplied from the reserve tank 27 to the developing device 14 through the shutter 61 that opens the shutter in synchronization with the toner supply operation of the toner supply mechanism 56.

  The developing device 14 includes a fin screw 62 having the same configuration as that of the toner transport mechanisms 47 and 56 described above. In FIG. 2B, the first stirring and conveying screw 18 and the second stirring and conveying screw 19 shown in FIG. 1 are simply shown as one fin screw 62.

  A developing device motor 63 is connected to the rotation shaft of the fin screw 62. The developing device 14 supplies toner to the developing roller 15 while stirring and conveying the toner 49 by the fin screw 62 driven by the developing device motor 63.

  The developing unit 14 is also provided with a detected part 64 that indicates whether the developing unit 14 is new or old. A detecting part 65 that detects the new or old of the developing unit 14 by the detected part 64 is provided on the main body side of the printer 1. The detecting device 66 including the detected portion 64 and the detecting portion 65 for detecting whether the developing device 14 is new or old can also be configured by a very general and inexpensive method. In addition, a toner density sensor 67 is disposed at an appropriate location in the developing device 14.

  3 is an enlarged view of the developing device 9 of the image forming unit 2 of the printer 1 shown in FIG. 1 and the reserve tank 27 and toner cartridge 28 of the toner supply unit 4 together with the transfer belt 8. As shown in FIG. FIG. 3 also shows an image forming apparatus main body frame 68. FIG. 3 is shown here for easy understanding of the usage mode of a special toner consumable (preliminary development device) described later.

  In FIG. 3, the toner replenishment paths 59 shown in FIGS. 2A and 2B are virtually indicated by broken lines because these toner replenishment paths 59 are closer to the drawing surface than the transfer belt unit 3. This is because it is arranged on the other side in the depth direction and is not actually visible in this figure.

  In FIG. 3, the end portion of the toner supply path 59 is indicated by an arrow so that the shutter 61 shown in FIG. 2B can supply the toner 49 to the developing device 9 at any time. This is to show that it is in a standby state.

  FIG. 4 is a diagram illustrating a usage mode in the case where printing is performed using special toner by the printer 1 of this example. In FIG. 4, only parts necessary for explanation are given numbers. The other parts are the same as in FIG.

  As shown in FIG. 4, the printer 1 of this example is provided with a toner consumable (preliminary development device) 9 r that contains rewritable toner as special toner in advance as a spare part.

  In the printer 1 of this example, when developing with special toner, first, the shutter 61 of the toner supply path 59 connected to the developing device 9k is closed. Next, the connection between the developing device 9k and the toner supply path 59 is disconnected.

  Subsequently, the developing device 9k is removed from the arrangement position as shown by the arrow c in FIG. 4, and the preliminary developing device 9r is attached and arranged at the arrangement position where the developing device 9k is removed as shown by the arrow d. Then, development with special toner is executed by the preliminary developing device 9r.

  The reason why the original developing device to be replaced with the preliminary developing device 9r as described above is the developing device 9k for monochrome printing is that only the developing device 9k can be driven independently. The other three developing devices 9c, 9m, and 9y are stopped during development with special toner.

  FIGS. 5 and 6 are diagrams illustrating other usage modes when printing is performed using special toner by the printer 1 of the present example. In FIG. 5 and FIG. 6, only parts necessary for explanation are given numbers. The other parts are the same as in FIG.

  In the printer 1 of this example, when developing with special toner, first, two connected to two adjacent developing devices 9k and 9c in a plurality (four in this example) of developing devices 9 shown in FIG. The shutters 61 and 61 of the two toner supply paths 59 and 59 are closed.

  Next, the connection between the two developing devices 9k and 9c and the two developer supply paths 59 and 59 is disconnected. Subsequently, the developing devices 9k and 9c are removed from the arrangement positions as indicated by arrows f and e in FIG.

  As shown in FIG. 6, in the printer 1 of this example, in addition to a toner consumable (preliminary development device) 9r containing rewritable toner as a special toner, the rewritable toner as a special toner is further supplied to the preliminary development device 9r. A spare replenishing device 69 is provided in advance as a spare part.

  Then, the preliminary developing device 9r is attached and arranged at the arrangement position from which the developing device 9k is removed, as shown in FIG. Further, the preliminary replenishing device 69 is attached and arranged at the arrangement position where the developing device 9c is removed.

  Then, the preliminary developing device 9r and the preliminary replenishing device 69 are connected, and development with the special toner by the preliminary developing device 9r is executed while supplying the special toner to the preliminary developing device 9r by the preliminary replenishing device 69.

  Also in this example, the original developing device to be replaced with the preliminary developing device 9r is the developing device 9k for monochrome printing because only the developing device 9k can be driven independently.

  Further, since the developing device 9c adjacent to the developing device 9k is a developing device whose driving is stopped together with the other two developing devices 9m and 9y during development with the special toner, there is no problem even if it is removed.

  During the development with the special toner as described above, the cartridge motor 48 shown in FIG. 2B of the toner cartridge 28 (28k, 28c, 28m, 28y) and the reserve tank 27 (27k, 27c, 27m, 27y). The drive of the reserve tank motor 57 is stopped.

  The developing device motor 63 shown in FIG. 2B of the developing devices 9m and 9y is also stopped driving, and the developing device motors 63 corresponding to the developing devices 9k and 9c are disengaged from the developing devices, respectively. The drive is stopped at.

  FIGS. 7A and 7B are diagrams showing two examples in which the internal configurations are different in a state where the preliminary developing device 9r and the preliminary replenishing device 69 are connected.

  In the example shown in FIG. 7A, the spare replenishing device 69-1 has a slightly larger agitator 71 that rotates in the center of the inside to match the internal capacity of the spare replenishing device 69-1, and stirs the internal special toner. ing. At the replenishing port 72, a slightly small agitator 73 is rotated in accordance with the opening of the replenishing port 72 to replenish special toner to the receiving port 74 of the preliminary developing device 9r-1.

  In this embodiment, the agitators 71 and 73 are constituted by a rotation shaft having a length substantially corresponding to the length of the apparatus main body in the depth direction of the drawing, and a plate blade fixed to the rotation shaft.

  The replenishing port 72 and the receiving port 74 are each composed of an opening having a length substantially corresponding to the length of the apparatus main body in the depth direction of the drawing. The replenishing port 72 and the receiving port 74 are provided with shutters so that the internal special toner does not leak to the outside when they are single, but they are not shown.

  The other pre-developing device 9r-1 shown in FIG. 7 (a) is shown with the same components as those shown in FIGS. 1 and 3 having the same numbers as those shown in FIGS. . The preliminary developing device 9r-1 shown in FIG. 7A supplies the special toner replenished from the receiving port 74 to the developing roller 15 while rotating and stirring the two agitators 75 arranged vertically. .

  Next, in the example shown in FIG. 7B, the preliminary supply device 69-2 includes two screw mechanisms 77 along the inner center and the inner wall where the supply port 76 is located. Each of the two screw mechanisms 77 includes a rotating shaft and a helical screw fin fixed to the rotating shaft.

  The two screw mechanisms 77 extend along the longitudinal direction from the front end in the depth direction of the drawing of the preliminary supply device 69-2 to the end on the opposite side. Among these, the screw mechanism 77 arranged along the inner wall with the supply port 76 forms a fin-shaped change point on the side of the supply port 76 at the end portion which is not visible in the drawing because of a sectional view. The toner is supplied from the supply port 76 to the preliminary developing device 9r-2.

  In the other preliminary developing device 9r-2 shown in FIG. 7B, the toner receiving port to be connected to the toner supply path 59 shown in FIG. 5 in the replaced developing device 9k is the receiving port shown in FIG. The other parts are the same as those of the developing device 9 shown in FIGS. 1 to 3 except that the position of the developing device 9 is changed to be moved to the position 78 and connected to the preliminary supply device 69-2.

  As described above, according to the above-described embodiments, the special developing parts 9r, 9r-1, 9r-2, the preliminary replenishing device 69-1, and the special replenishing device 69-2 are provided with the special toner consumables. The original developing device 9 and the toner cartridge 28, the reserve tank 27, and the toner replenishment path 59, which are members around the developing device, are not required to be cleaned before and after the use of special toner. An image forming apparatus that can be easily exchanged with the special toner developing device is realized.

  Thereby, it becomes easy to make a normal color printer function as a rewritable printer. In addition, the present invention is not limited to the printer of the form such as the printer 1 shown in FIG. 1. For example, in a developing device that uses a one-component toner and has a toner conveyance path between the toner set and the drum set. It is also effective for switching between normal toner and special toner.

  In the above-described embodiments, the rewritable toner has been described as the special toner. However, the special toner is not limited to the rewritable toner. For example, a normal toner that is normally developed by the developing device such as a fluorescent toner is used. It can be applied to any toner that is different from.

  The present invention can be used for an image forming apparatus provided with a special toner consumable that does not require a process such as cleaning before and after use, and that can be easily replaced by a user.

1 Full-color image forming device (printer)
2 Image forming unit 3 Transfer belt unit 4 Toner supply unit 5 Paper feeding unit 6 Belt fixing unit 7 Double-sided printing transport unit 8 Transfer belt 8a Lower running unit surface 9 (9m, 9c, 9y, 9k) Developing devices 9r, 9r -1, 9r-2 Preliminary developing device for special toner 10 Photosensitive drum 11 Cleaner 12 Charging roller 13 Optical writing head 14 Developer 15 Developing roller 16 Housing 17 Partition 15 Developing roller 18 First stirring and conveying screw 19 Second Agitating and conveying screw 20 primary transfer roller 21 driving roller 22 driven roller 23 secondary transfer unit 24 belt cleaner 25 cleaning blade 26 waste toner collection container 27 (27m, 27c, 27y, 27k) reserve tank 28 (28m, 28c, 28y, 28k) Toner cartridge 29 (29a, 9b) Paper feed cassette 30 Electrical section 31 Paper take-out roller 32 Feed roller 33 Rolling roller 34 Standby transport roller pair 35 Secondary transfer roller 36 Unload roller pair 37 Paper discharge tray 38 Paper discharge roller pair 39 Return path 39a Start return path 39b Intermediate return path 39c End return path 41 (41a, 41b, 41c, 41d, 41e) Return roller pair 42 Detected part 43 Detection part 44 Detection device 45 Rotating shaft 46 Stirring fin 47 Toner replenishment mechanism 48 Cartridge motor 49 Toner 51 Toner replenishment Port 52 Change point of fin shape 53 Toner empty detection sensor 54 Rotating shaft 55 Stirring fin 56 Toner supply mechanism 57 Reserve tank motor 58 Change point of fin shape 59 Toner supply path 61 Shutter 62 Fin screw 63 Developer motor 64 Detected part 65 detection 66 sensing unit 67 the toner density sensor 68 the image forming apparatus main body frame 69,69-1,69-2 special toner spare supply device 71, 73, 75 agitator 72 supply port 74 receiving opening 76 supplying opening 77 screw mechanism 78 receiving opening

Claims (3)

An image forming apparatus in which a plurality of developing devices arranged side by side in a tandem system and a plurality of developer containers for supplying a developer to the plurality of developing devices are disposed apart from each other via a plurality of developer supply paths. Because
A shutter disposed at each end of the plurality of developer supply paths connected to the plurality of developing devices from the plurality of developer containers;
A pre-development device that performs development with a special toner different from the normal toner used by the plurality of development devices for development;
A preliminary supply device for supplying the special toner to the preliminary development device;
With
When developing with the special toner,
Closing the shutters of the two developer supply paths connected to two adjacent developing devices in the plurality of developing devices;
Disconnecting the connection between the two developing devices and the two developer supply paths,
Removing the two developing devices from the first or second arrangement position, which is the respective arrangement position;
The preliminary developing device is disposed at the first disposition position where the two developing devices are removed;
The preliminary replenishing device is disposed at the second disposition position from which the two developing devices are removed;
Connecting the preliminary developing device and the preliminary supply device;
Developing with the special toner by the preliminary developing device while supplying the special toner to the preliminary developing device by the preliminary replenishing device;
An image forming apparatus. The special toner is a fluorescent toner or rewritable toner claim 1 Symbol placing the image forming apparatus, characterized in that. The developer is one-component is a toner or two-component developer according to claim 1, SL placing the image forming apparatus, characterized in that.