JP5790935B2 - 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 a copying machine, a printer, a facsimile, and a multifunction machine having these functions in combination, and more particularly, to an image forming apparatus having a plurality of image forming portions having different image forming speeds. .

  Conventionally, as an image forming method used in this type of image forming apparatus, an electrophotographic method or an ink jet method is known.

  For example, in an electrophotographic image forming apparatus, an electrostatic latent image is formed on a photosensitive drum by irradiating a charged photosensitive drum with laser light corresponding to an image signal. The toner image formed on the photosensitive drum is printed on the recording material through each process such as development, transfer, and peeling.

  On the other hand, in an inkjet image forming apparatus, an image is printed on a recording material by ejecting ink corresponding to an image signal from each nozzle.

  Here, in general offices and the like, the majority of printing is monochrome printing, and there are many uses that include color printing in part, but there is a great need for color printing. Each image forming method has advantages and disadvantages.

  For example, an electrophotographic image forming apparatus capable of printing a color image has a complicated hardware configuration. As a result, the manufacturing cost and introduction cost of the image forming apparatus increase. Further, as described above, since most printing is monochrome printing, the color image forming unit is not frequently used.

  On the other hand, in an inkjet image forming apparatus, it is known that the printing speed of monochrome printing, which is the main application, is slower than that of an electrophotographic method. Furthermore, it is also known that the printing cost of the ink jet method per sheet is higher than that of the electrophotographic method.

  In order to improve this point, a technique is known in which monochrome printing is performed by an electrophotographic method and color printing is performed by an inkjet method (for example, Patent Documents 1 and 2).

  In the techniques of Patent Documents 1 and 2, monochrome printing can be performed by an electrophotographic method, and color printing can be performed by an inkjet method. Therefore, the techniques of Patent Documents 1 and 2 have an advantage that high speed and high image quality in monochrome printing and low cost in color printing can be realized at the same time.

JP-A-8-164636 JP 2009-220508 A

  However, in the technique of Patent Document 1, the color conveyance path for the color image forming unit and the monochrome conveyance path for the monochrome image forming unit are connected in series along the conveyance direction of the recording material. Therefore, when the recording material that has passed through the upstream image forming section passes through the downstream image forming section, the ink or toner on the recording material may adhere to the downstream image forming section and adversely affect the recording material. was there. For example, in an image forming apparatus having a color image forming unit on the upstream side and a monochrome image forming unit on the downstream side, when a recording material color-printed by an inkjet method passes through a monochrome conveyance path for the monochrome image forming unit, There has been a problem in that undried ink adheres to the monochrome image forming portion and adversely affects the monochrome image forming portion.

  Therefore, an object of the present invention is to provide an image forming apparatus that can print an image on a recording material satisfactorily even when it has a plurality of image forming units.

In order to solve the above problems, the invention of claim 1 is an image forming apparatus comprising a monochrome image forming unit that prints a monochrome image on a recording material supplied via a monochrome conveyance path, and a color conveyance path. A color image forming unit that prints a color image on the recording material supplied via the sheet, and a path of the recording material supplied via a paper feed path, the monochrome conveyance path, and the color conveyance path. A first switching section for switching to any one of the above, a path for the recording material supplied via the color transport path, a color paper discharge path for guiding the recording material to a paper discharge tray, and a downstream of the monochrome transport path The first common transport path connected to the side is supplied via the second switching section for switching to one of the bridging paths for guiding the recording material, the monochrome transport path, and the first common transport path. The path of the recording material A third switching section for switching between a monochrome discharge path for guiding the recording material to the tray side and a second common transport path connected to the downstream side of the first common transport path; and the second common It is provided on the downstream side of the conveyance path so that the recording material supplied from the second common conveyance path is guided to the reversing path and the recording material supplied from the reversing path is guided to the circulation conveying path, respectively. a fourth switching section for switching the path of the recording material, and a reversing section for reversing the conveyance direction of the recording material supplied through the reversing path, downstream and the color discharge before Symbol monochrome discharge path And a common paper discharge path connected to each of the downstream sides of the path, and the circulation conveyance path supplies the recording material supplied via the fourth switching unit to the first switching unit. And

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the reversing unit reverses the conveying direction of the recording material supplied via the reversing path and supplies the reversing path to the reversing path. The recording material thus discharged is discharged to the discharge tray.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the monochrome image forming unit and the color image forming unit are disposed in a space surrounded by the monochrome transport path and the color transport path. And a high-voltage power supply for applying a high voltage to the color image forming unit.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the monochrome image forming unit and the color image forming unit receive black toner from the same black toner container. It is characterized by receiving supply.

  In the invention described in claims 1 to 4, the paper feed path branches into a monochrome transport path and a color transport path. The monochrome transport path is connected to the common paper discharge path via the first common transport path and the monochrome paper discharge path, and the color transport path is connected to the common paper discharge path via the color paper discharge path. Yes. Further, the recording material is discharged to the discharge tray side through the common discharge path.

  In this way, the recording materials that have been printed by the monochrome image forming unit and the color image forming unit are all guided to the common discharge path on the discharge tray side. As a result, even when the monochrome image forming unit and the color image forming unit are arranged in parallel, the discharge tray can be shared. Therefore, the number of parts of the image forming apparatus can be reduced, and the manufacturing cost of the image forming apparatus can be reduced.

  In the inventions according to claims 1 to 4, the reverse path is provided separately from the monochrome paper discharge path, the color paper discharge path, and the common paper discharge path. Thus, the recording material can be discharged to the common paper discharge path regardless of whether or not the recording material exists on the reverse path. This eliminates the need for a reversal waiting time and improves the printing efficiency of the image forming apparatus.

2 is a diagram illustrating an example of a hardware configuration of a printer according to the first embodiment of the present invention. FIG. It is a figure which shows an example of the hardware constitutions of the printer in the 2nd Embodiment of this invention.

  Hereinafter, an embodiment in which the present invention is applied to a digital printer (hereinafter referred to as a printer) which is an example of an image forming apparatus will be described with reference to the drawings.

<1. First Embodiment>
<1.1. Printer Overview>
FIG. 1 is a diagram illustrating an example of a hardware configuration of the printer 1 according to the present embodiment. The printer 1 is an image forming apparatus that prints a monochrome image and a color image by an electrophotographic method. The printer 1 also has a circulation type double-sided printing function. As shown in FIG. 1, the printer 1 mainly includes a monochrome image forming unit 10, a color image forming unit 101, a paper feeding unit 20, and a circulation conveyance unit 40.

  The monochrome image forming unit 10 and the color image forming unit 101 are arranged side by side on the paper feeding unit 20 in the horizontal direction. Although not shown, the printer 1 is connected to a network such as a LAN, and receives a monochrome print command or a color print command from an external terminal (not shown) or the like, and then receives a monochrome print job or color print based on the command. Configured to run jobs. These print jobs include a job in a single-side mode for printing (image formation) on one side of the recording material P and a job in a double-side mode for printing on one side and the other side of the recording material P.

  In the present embodiment, the image forming speed by the color image forming unit 101 is slower than the image forming speed by the monochrome image forming unit 10. Further, the conveyance speed of the recording material P in the monochrome conveyance path Ra and the color conveyance path Rb, which will be described later, is variable. Further, arrows attached to the respective transport paths R1 to R9, Ra, and Rb in FIG. 1 indicate the transport direction of the recording material P.

  The monochrome image forming unit 10 plays a role of transferring a monochrome toner image formed on the monochrome photosensitive drum 13 to the recording material P by a known electrophotographic method. Thereby, a monochrome image is printed on the recording material P supplied via the monochrome conveyance path Ra.

  The monochrome photosensitive drum 13 of the monochrome image forming unit 10 is driven to rotate counterclockwise in FIG. Around the monochrome photosensitive drum 13, a monochrome exposure unit 15, a charging unit, a developing unit, a static elimination lamp, a photosensitive member cleaner (all not shown), and the like are arranged.

  As shown in FIG. 1, the monochrome photosensitive drum 13 and the monochrome transfer roller 7 face each other, and the monochrome photosensitive drum 13 and the monochrome transfer roller 7 abut at a monochrome transfer position 18. The developer of the monochrome image forming unit 10 is preferably a two-component developer composed of a toner and a carrier, but may be a one-component developer that does not use a carrier.

  The color image forming unit 101 is a tandem type that plays a role of transferring a color toner image formed on the color photosensitive drum 103 to the recording material P by a known electrophotographic method. Thereby, a color image is printed on the recording material P supplied via the color transport path Rb.

  The color image forming unit 101 includes a total of four image forming units 102 corresponding to respective colors of yellow (Y), magenta (M), cyan (C), and black (K), an intermediate transfer belt 111, and the like. . The four image forming units 102 are arranged below the intermediate transfer belt 111 along the intermediate transfer belt 111 in the order of yellow, magenta, cyan, and black, for example. Each image forming unit 102 has a color photosensitive drum 103 that is driven to rotate counterclockwise in FIG.

  In the present embodiment, the monochrome image forming unit 10 and the color image forming unit 101 are unitized and can be separated from the apparatus main body 1a.

  Around the color photoconductor drum 103, a color exposure unit 105, a charging unit, a developing unit, a primary transfer roller, a photoconductor cleaner (all not shown), and the like are arranged. In FIG. 1, for convenience of explanation, symbols Y, M, C, and K corresponding to reproduced colors are attached to the image forming unit 102 and the color photosensitive drum 103, respectively.

  The intermediate transfer belt 111 is wound around a driving roller 112 and a driven roller 113, and is driven to rotate counterclockwise in FIG. A secondary transfer roller 114 is disposed outside the portion of the intermediate transfer belt 111 that is wound around the drive roller 112. The intermediate transfer belt 111 and the secondary transfer roller 114 abut at the color transfer position 118. A transfer belt cleaner (not shown) for removing untransferred toner on the intermediate transfer belt 111 is disposed outside the portion of the intermediate transfer belt 111 that is wound around the driven roller 113. The image forming speed of the color image forming unit 101 is slower than that of the monochrome image forming unit 10.

  The developer of the color image forming unit 101 is preferably a one-component developer that does not use a carrier, but may be a two-component developer that includes a toner and a carrier. The color image forming unit 101 is not limited to the electrophotographic system, but may be other than the electrophotographic system, for example, an inkjet system or a toner jet system.

  The sheet feeding unit 20 is shared by the monochrome image forming unit 10 and the color image forming unit 101, and includes a plurality of stages of sheet feeding cassettes 21 that store the recording material P, and the recording materials P in each sheet feeding cassette 21. Are provided with a feeding roller 22 that feeds the recording material P from the uppermost layer, a separation roller pair 23 that separates the fed recording material P one by one. The recording material P in each paper feed cassette 21 is sent out to the paper feed path R1 one by one from the top layer by the rotational drive of the corresponding feed roller 22 and separation roller pair 23. The paper feed path R1 extending from the paper feed unit 20 (each paper feed cassette 21) once merges into a monochrome transport path Ra for the monochrome image forming unit 10 and a color transport path Rb for the color image forming unit 101. Branched.

  Note that the printer 1 of the first embodiment is an A3-compatible machine, and a vertical A3 size recording material P enters each of the paper feed cassettes 21 from the short side into the image forming units 10 and 101 and the like. It is possible to accommodate in the feeding posture. In this case, the width dimension length of the A3 vertical recording material P is 297 mm, and the length in the transport direction is 420 mm.

  The path switching claw 25 (first switching unit) switches the path of the recording material P supplied via the paper feed path R1 to either the monochrome transport path Ra or the color transport path Rb. More specifically, the path switching claw 25 is (a) closed on the color transport path Rb side by the excitation of a solenoid (not shown) connected to the control unit 60 described later, and is connected to each paper feed path R1. The state is switched between the state where the monochrome transport path Ra is connected and the state where (b) the monochrome transport path Ra side is closed and each paper feed path R1 and the color transport path Rb are connected. Therefore, the recording material P supplied from each paper feed cassette 21 of the paper feed unit 20 can be conveyed to one of the image forming units 10 and 101 by the switching operation of the path switching claw 25.

  As shown in FIG. 1, the registration roller pair 24 is provided at a position between the monochrome transfer position 18 and the path switching claw 25 on the path along the monochrome transport path Ra. The timing at which the recording material P is sent out to the monochrome transfer position 18 is controlled by controlling the rotation operation of the registration roller pair 24.

  The upstream relay roller pair 123 and the registration roller pair 124 are provided at a position between the color transfer position 118 and the path switching claw 25 on the path along the color transport path Rb. As shown in FIG. 1, the upstream relay roller pair 123 and the registration roller pair 124 are provided in this order from the upstream side to the downstream side in the conveyance direction of the recording material P.

  The upstream relay roller pair 123 relays the conveyance operation of the recording material P that is conveyed toward the registration roller pair 124. Further, the timing at which the recording material P is sent out to the color transfer position 118 is controlled by controlling the rotation operation of the registration roller pair 124.

  The monochrome fixing unit 30 fixes the monochrome toner image transferred onto the recording material P. As shown in FIG. 1, the monochrome fixing unit 30 is disposed on the downstream side of the monochrome transfer position 18 in the path along the monochrome transport path Ra, and mainly includes a fixing roller 31 and a pressure roller 32. And have.

  The fixing roller 31 has a built-in fixing heater such as a halogen lamp. The pressure roller 32 is provided to face the fixing roller 31 and presses the recording material P between the rollers 31 and 32. Both rollers 31 and 32 abut at the monochrome fixing position.

  The color fixing unit 130 fixes the color toner image transferred onto the recording material P. As shown in FIG. 1, the color fixing unit 130 is disposed on the downstream side of the color transfer position 118 in the path along the color transport path Rb, and mainly includes the fixing roller 131 and the pressure roller 132. And have.

  As with the fixing roller 31, the fixing roller 131 includes a fixing heater such as a halogen lamp. The pressure roller 132 is provided to face the fixing roller 131 and presses the recording material P between the rollers 131 and 132. Both rollers 131 and 132 abut at the color fixing position.

  The path switching claw 145 (second switching unit) switches the path of the recording material P supplied via the color transport path Rb to either the bridging path R4 or the color paper discharge path R6. More specifically, the path switching claw 145 is closed by the excitation of a solenoid (not shown) connected to the control unit 60 described later, and (c) the color paper discharge path R6 side is closed, and the color transport path Rb. The state is switched between the state where the bridge path R4 is connected and the state where (d) the bridge path R4 side is closed and the color transport path Rb and the color paper discharge path R6 are connected.

  As shown in FIG. 1, the bridging path R4 is connected to the first common transport path R8, and the first common transport path R8 is on the downstream side of the monochrome transport path Ra in the transport direction of the recording material P. It is connected.

  Further, as shown in FIG. 1, the color paper discharge path R6 is connected to the common paper discharge path R7, and guides the recording material P to the paper discharge tray 52 side. For example, the recording material P immediately after the color printing is performed is guided to the color paper discharge path R6.

  The path switching claw 155 (third switching unit) includes a path for the recording material P supplied via the monochrome transport path Ra and the first common transport path R8, the monochrome discharge path R5, and the second common transport path R9. Switch to one of the following. More specifically, the path switching claw 155 is (e) the second common transport path R9 side is closed by the excitation of a solenoid (not shown) connected to the control unit 60 described later, and the first common transport is performed. Switching between the state in which the path R8 and the monochrome discharge path R5 are connected and the state in which the (f) monochrome discharge path R5 side is closed and the first and second common transport paths R8 and R9 are connected are switched. .

  As shown in FIG. 1, the second common transport path R9 is connected to the downstream side of the first common transport path R8 in the transport direction of the recording material P. Further, as shown in FIG. 1, the monochrome paper discharge path R5 guides the recording material P to the paper discharge tray 52 side.

  The reversing roller pair 51 (reversing unit) reverses the conveyance direction of the recording material P supplied via the reversing path R2. As shown in FIG. 1, the recording material P reversed by the reversing roller pair 51 is supplied to the circulation conveyance path R <b> 3 via the reversing path R <b> 2 and the path switching claw 45.

  The paper discharge roller pair 53 discharges the printed recording material P to the paper discharge tray 52. As shown in FIG. 1, the paper discharge roller pair 53 is provided in the common paper discharge path R7. For example, the recording material P on which color printing has been executed and / or the recording material P on which monochrome printing has been executed are discharged to the paper discharge tray 52, respectively.

  Here, as shown in FIG. 1, the reversing roller pair 51 is provided facing the paper discharge tray 52. Therefore, when the rotation direction of the reversing roller pair 51 is not reversed and the conveyance direction of the recording material P is not reversed, the recording material P supplied to the reversing path R2 is discharged to the paper discharge tray 52. As described above, the reversing roller pair 51 has a function as a discharge unit, like the paper discharge roller pair 53.

  The circulation conveyance unit 40 includes a reversing roller pair 51 as a reversing unit for reversing the recording material P after single-sided printing, and a plurality of double-sided conveyance roller pairs 41 and 42. In the circulation conveyance unit 40, the recording material P after single-sided printing is turned upside down and conveyed again to the registration roller pairs 24 and 124 via the circulation conveyance path R3.

  As shown in FIG. 1, the path switching claw 45 (fourth switching unit) is provided on the downstream side of the second common transport path R9 in the transport direction of the recording material P. The path switching claw 45 performs recording so that the recording material P supplied from the second common transport path R9 is guided to the reversing path R2, and the recording material P supplied from the reversing path R2 is guided to the circulation transport path R3. The path of the material P is switched.

  More specifically, the path switching claw 45 is (g) closed on the second common transport path R9 side by excitation of a solenoid (not shown) connected to the control unit 60 described later, and the reversing path R2. The state is switched between the state in which the circulation conveyance path R3 is connected and the state in which (h) the circulation conveyance path R3 side is closed and the second common conveyance path R9 and the reverse path R2 are connected.

  Note that, for example, the recording material P on which monochrome printing has been performed is guided to the monochrome paper discharge path R5. Further, as shown in FIG. 1, the circulation conveyance path R <b> 3 supplies the recording material P supplied via the path switching claw 45 to the path switching claw 25.

  A control unit 60 is disposed between the uppermost sheet feeding unit 20 and the upstream relay roller pair 123. The control unit 60 receives an image signal from an external terminal (not shown) or the like, converts it into digitized image data for YK color, and outputs the monochrome image forming unit 10, the color image forming unit 101, and the supply unit. The printing operation is executed by controlling the paper unit 20 and the like.

  A high voltage power source 19 is disposed in a space surrounded by the monochrome transport path Ra and the color transport path Rb in the apparatus main body 1a. The high voltage power supply 19 applies a high voltage to the monochrome image forming unit 10 and the color image forming unit 101. As shown in FIG. 1, the high voltage power supply 19 is arranged near the center of the monochrome image forming unit 10 and the color image forming unit 101, so that the monochrome image forming unit 10 and the color image forming unit 101 include the monochrome image forming unit 101. In addition, the color exposure units 15 and 105, the high-voltage power source 19 and the like can be collectively arranged in the apparatus main body 1a.

<1.2. Double-sided printing operation of printer>
Here, an example of a method of performing duplex printing by the printer 1 will be described with reference to FIG. Specifically, (1) When color printing is performed on each of the one side and the other side of the recording material P, (2) When monochrome printing is performed on each of the one side and the other side of the recording material P (3) When color printing is performed on one side of the recording material P and then monochrome printing is performed on the other side; and (4) After monochrome printing is performed on one side of the recording material P, the other A case where color printing is executed in the direction will be described. <1.2.1. When color printing is performed on both sides>
When color printing is performed on both sides of the recording material P, the recording material P supplied from each paper supply unit 20 is supplied to the color transport path Rb via the paper supply path R1 by the switching operation of the path switching claw 25. Is done. As a result, color printing is performed on one surface of the recording material P.

  Next, by the switching operation of the path switching claw 145, the recording material P is supplied to the reversing roller pair 51 via the bridging path R4, the first and second common transport paths R8, R9, and the reversing path R2. Thereby, the recording material P is reversed by the reversing roller pair 51.

  Subsequently, the reversed recording material P is supplied again to the color transport path Rb through the reverse path R2, the path switching claw 45, the circulation transport path R3, and the path switching claw 25. As a result, color printing is performed on the other surface of the recording material P.

  Then, the recording material P printed on both sides is discharged to the paper discharge tray 52 through the path switching claw 145, the color paper discharge path R6, and the common paper discharge path R7.

<1.2.2. When monochrome printing is performed on both sides>
When monochrome printing is performed on both sides of the recording material P, the recording material P supplied from each paper supply unit 20 is supplied to the monochrome conveyance path Ra via the paper supply path R1 by the switching operation of the path switching claw 25. Is done. Thereby, monochrome printing is performed on one surface of the recording material P.

  Next, by the switching operation of the path switching claw 155 and the path switching claw 45, the recording material P is supplied to the reversing roller pair 51 via the first and second common transport paths R8, R9 and the reversing path R2. . Thereby, the recording material P is reversed by the reversing roller pair 51.

  Subsequently, the reversed recording material P is supplied again to the monochrome conveyance path Ra via the reversal path R2, the path switching claw 45, the circulation conveyance path R3, and the path switching claw 25. Thereby, monochrome printing is executed on the other side of the recording material P.

  Then, the recording material P printed on both sides is discharged to the discharge tray 52 via the path switching claw 155, the monochrome discharge path R5, and the common discharge path R7.

<1.2.3. When monochrome printing is performed after color printing>
When color printing is performed on one side of the recording material P and then monochrome printing is performed on the other side, the recording material P supplied from each paper feed unit 20 is fed by the switching operation of the path switching claw 25. The paper is supplied to the color transport path Rb through the paper path R1. As a result, color printing is performed on one surface of the recording material P.

  Next, by the switching operation of the path switching claw 145, the recording material P is supplied to the reversing roller pair 51 via the bridging path R4, the first and second common transport paths R8, R9, and the reversing path R2. Thereby, the recording material P is reversed by the reversing roller pair 51.

  Subsequently, the reversed recording material P is supplied to the monochrome conveyance path Ra via the reversal path R2, the path switching claw 45, the circulation conveyance path R3, and the path switching claw 25. Thereby, monochrome printing is executed on the other side of the recording material P.

  Then, the recording material P printed on both sides is discharged to the discharge tray 52 via the path switching claw 155, the monochrome discharge path R5, and the common discharge path R7.

<1.2.4. When color printing is executed after monochrome printing>
When monochrome printing is performed on one side of the recording material P and then color printing is performed on the other side, the recording material P supplied from each paper feeding unit 20 is fed by the switching operation of the path switching claw 25. It is supplied to the monochrome conveyance path Ra via the paper path R1. Thereby, monochrome printing is performed on one surface of the recording material P.

  Next, by the switching operation of the path switching claw 155 and the path switching claw 45, the recording material P is supplied to the reversing roller pair 51 via the first and second common transport paths R8, R9 and the reversing path R2. . Thereby, the recording material P is reversed by the reversing roller pair 51.

  Subsequently, the reversed recording material P is supplied to the color transport path Rb via the reverse path R2, the path switching claw 45, the circulation transport path R3, and the path switching claw 25. As a result, color printing is performed on the other surface of the recording material P.

  Then, the recording material P printed on both sides is discharged to the paper discharge tray 52 through the path switching claw 145, the color paper discharge path R6, and the common paper discharge path R7.

<1.3. Advantages of Printer of First Embodiment>
As described above, in the printer 1 of the present embodiment, the paper feed path R1 branches into the monochrome transport path Ra and the color transport path Rb. The monochrome transport path Ra is connected to the common paper discharge path R7 via the first common transport path R8 and the monochrome paper discharge path R5, and the color transport path Rb is connected to the common paper discharge path R6 via the common paper discharge path R6. It is connected to the paper path R7. Further, the recording material P is discharged to the discharge tray 52 side through the common discharge path R7.

  In this manner, the recording material P on which printing has been executed by the monochrome image forming unit 10 and the color image forming unit 101 is guided to the common paper discharge path R7 on the paper discharge tray 52 side. Thereby, even when the monochrome image forming unit and the color image forming unit are arranged in parallel, the discharge tray 52 can be shared. Therefore, the number of parts of the printer 1 can be reduced, and the manufacturing cost of the printer 1 can be reduced.

  In the printer 1 of the present embodiment, the reversing path R2 is provided separately from the monochrome paper discharging path R5, the color paper discharging path R6, and the common paper discharging path R7. Accordingly, the recording material P can be discharged to the common discharge path R7 regardless of whether or not the recording material P exists on the reversing path R2. Therefore, the reversal waiting time is unnecessary, and the printing efficiency of the printer 1 can be improved.

<2. Second Embodiment>
Next, a second embodiment of the present invention will be described. FIG. 2 is a diagram illustrating an example of a hardware configuration of the printer 200 according to the second embodiment. As shown in FIG. 2, the printer 200 of the second embodiment is the same as the printer 1 of the first embodiment except that the hardware configuration of the exposure unit is different.

  Therefore, in the following, this difference will be mainly described. In the following description, the same components as those in the printer 1 according to the first embodiment are denoted by the same reference numerals. Since the components with the same reference numerals have already been described in the first embodiment, description thereof will be omitted in the present embodiment.

  The exposure unit 205 forms an electrostatic latent image on each color photosensitive drum 103Y, 103M, 103C, 103K by irradiating each color photosensitive drum 103Y, 103M, 103C, 103K with laser light. The exposure unit 205 forms an electrostatic latent image on the monochrome photosensitive drum 13 by irradiating the monochrome photosensitive drum 13 with laser light.

  As described above, the printer 200 according to the present embodiment can form an electrostatic latent image on the monochrome image forming unit 10 and the color image forming unit 101 by the common exposure unit 205. Therefore, the number of parts of the printer 200 can be further reduced, and the manufacturing cost of the printer 200 can be further reduced.

  In addition, the printer 200 of the present embodiment includes path switching claws 25, 45, 145, and 155 similar to the printer 1 of the first embodiment, a reverse roller pair 51, and a paper discharge roller pair 53. The monochrome image forming unit 10 and the color image forming unit 101 are arranged in parallel.

  Therefore, the printer 200 according to the present embodiment can reduce the number of parts and the manufacturing cost of the printer 200, as with the printer 1 according to the first embodiment. Further, the reversal waiting time is not required, and the printing efficiency of the printer 200 can be improved.

  In the present embodiment, the monochrome image forming unit 10 and the color image forming unit 101 may be configured to share not only the exposure unit 205 but also a black toner container. In this case, black toner can be supplied from the same black toner container. Therefore, the number of parts of the printer 200 can be further reduced, and the manufacturing cost of the printer 200 can be further reduced.

<3. Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made.

  In the first and second embodiments, each of the monochrome image forming unit 10 and the color image forming unit 101 has been described as forming an image by electrophotography, but is not limited thereto. For example, the printing method of the color image forming unit 101 may be an inkjet method or a thermal transfer method.

1,200 Printer (image forming device)
DESCRIPTION OF SYMBOLS 1a Apparatus main body 10 Monochrome image formation part 20 Paper feed part 25 Path | route switching nail | claw (1st switching part)
30 Monochrome fixing unit 40 Circulating conveyance unit 45 Path switching claw (fourth switching unit)
50 Paper discharge part 51 Reverse roller pair (reverse part)
101 Color image forming unit 145 Path switching claw (second switching unit)
155 Route switching claw (third switching unit)
R1 paper feed path R2 reversal path R3 circulation transport path R4 bridge discharge path R5 monochrome paper discharge path R6 color paper discharge path R7 common paper discharge path R8 first common transport path R9 second common transport path Ra monochrome transport path Rb color transport path

Claims (4)

An image forming apparatus,
(a) a monochrome image forming unit that prints a monochrome image on a recording material supplied via a monochrome conveyance path;
(b) a color image forming unit that prints a color image on the recording material supplied via a color conveyance path;
(c) the path of the recording material supplied through the paper feed path,
The monochrome transport path;
The color transport path;
A first switching unit for switching to any one of
(d) a path of the recording material supplied via the color transport path,
A color paper discharge path for guiding the recording material to the paper discharge tray side;
A bridging path for guiding the recording material to a first common transport path connected to the downstream side of the monochrome transport path;
A second switching unit for switching to any one of
(e) a path of the recording material supplied via the monochrome transport path and the first common transport path;
A monochrome discharge path for guiding the recording material to the discharge tray;
A second common transport path connected to the downstream side of the first common transport path;
A third switching unit for switching to any one of
(f) provided downstream of the second common transport path;
The recording material supplied from the second common transport path is a reversing path,
The recording material supplied from the reversing path to the circulation conveyance path,
A fourth switching unit for switching the path of the recording material so as to guide each of them;
(g) a reversing unit that reverses the conveyance direction of the recording material supplied through the reversing path;
(h) a common discharge path connected to each of the downstream side of the monochrome discharge path and the downstream side of the color discharge path;
With
The image forming apparatus, wherein the circulation conveyance path supplies the recording material supplied via the fourth switching unit to the first switching unit. The image forming apparatus according to claim 1.
The inversion part is
(i) reversing the conveying direction of the recording material supplied through the reversing path,
(ii) The image forming apparatus, wherein the recording material supplied to the reversing path is discharged to the discharge tray. The image forming apparatus according to claim 1, wherein:
A high-voltage power supply that is disposed in a space surrounded by the monochrome conveyance path and the color conveyance path, and applies a high voltage to the monochrome image formation unit and the color image formation unit;
An image forming apparatus further comprising: The image forming apparatus according to any one of claims 1 to 3,
The image forming apparatus, wherein the monochrome image forming unit and the color image forming unit receive black toner from the same black toner container.

Images