JPH0745300B2 - Image forming device - Google Patents

Description

Detailed Description of the Invention

[Industrial applications]

The present invention relates to an image forming apparatus such as a copying machine or a printer using an electrophotographic method.

[Prior art]

In the past, in electrophotographic copying machines, printers such as laser printers and LED printers, it is easier to transfer the image on the photoconductor to the recording medium for transfer under the photoconductor. A transfer paper transfer path is provided on the lower side of the body, and a duplex transfer unit and a reversal unit are also arranged at the lower part of the apparatus main body. Further, when the transfer means is provided with a conveyance path of the recording paper for transfer on the upper side of the photoconductor (that is, when a suction belt or the like for conveying the paper is provided on the upper surface of the photoconductor),
A duplex conveying unit and a reversing unit are also arranged on the upper part of the apparatus main body, and it is known that the both are integrated and installed on the upper surface of the apparatus main body.

[Problems to be Solved by the Invention]

By the way, in such an image forming apparatus, when the former duplex conveying unit and reversing unit are arranged in the lower part of the apparatus main body, it is troublesome to remove the recording medium for transfer when the recording medium for transfer is clogged. In addition, the device itself required a complicated configuration. Moreover, since the transport passage is arranged in the lower part of the apparatus main body, it is not possible to form a linear transport path for the recording paper for transfer due to the relation between the paper feed port and the paper discharge port, and the recording paper is easily broken. It could only be transported on the transport path. Therefore, the recording paper is jammed and the quality of the image is deteriorated. In the latter case, when the duplex transport unit and the reversing unit are integrated and placed in the upper part of the device body, the upper surface of the device body is occupied as a large unit, so that the recording paper is not transferred to the transport path. If it becomes clogged, it is troublesome to remove it, and it requires a large space to open it. [Object of the Invention] The image forming apparatus of the present invention is capable of reliably conveying a recording medium, and can easily perform a processing operation even when a recording sheet is jammed, and further, the duplex conveying section and the reversing section. It is possible to reduce the space required when opening the device and downsize the device body,
Another object of the present invention is to provide an image forming apparatus which can easily take out the recording paper when taking out the recording paper, can cope with high speed operation of the image forming apparatus, and have improved operability.

[Means for solving problems]

In order to solve the above-mentioned drawbacks of the conventional example, the image forming apparatus of the present invention has a sheet conveying path located between the photoconductor and the transfer means for the sheet formed on the photoconductor so as to be openable and closable. An exposing means for exposing the photoreceptor to form an electrostatic latent image, a developing means for developing the electrostatic latent image to form a toner image, and a transferring means for transferring the toner image onto a recording medium. A main body unit including a main body unit and a feeding unit that is provided adjacent to the main body unit for feeding a recording medium to the main body unit, and that receives paper from the paper conveyance path above the main body unit. The duplex transport unit that transports the sheet and the duplex reversing unit that receives the sheet transported from the duplex transport unit, reverses the sheet, and transports the sheet to the sheet transport path of the main unit, respectively. It is installed in an upright state, and the duplex transport section and the duplex reversing section are each composed of an upper unit and a lower unit with a sheet transport path as a boundary, and the duplex transport section can be freely opened and closed with the main unit. It is characterized in that the sheet transfer path can also be opened by opening the sheet transfer means of the main body unit in a state where the duplex transfer section is opened. The present invention is also characterized in that the above-mentioned duplex reversing unit is arranged on the paper feeding unit. Further, the duplex conveying unit and the duplex reversing unit can be opened and closed by a rotary shaft parallel to the paper conveying direction, and the transfer unit can be opened and closed by a rotary shaft orthogonal to the paper conveying direction. I am trying.

【Example】

An embodiment of an image forming apparatus according to the present invention will be described below with reference to the drawings. <Structure> FIG. 1 is a diagram showing an outline of an image forming apparatus including an LED printer provided with a duplex conveying mechanism in an embodiment of the present invention. Reference numeral 11 denotes an image forming mechanism 12, that is, at least a photoconductor, an exposure device for exposing the photoconductor to form an electrostatic latent image, and a development for developing the electrostatic latent image to form a toner image. A main body unit having an image forming mechanism 12 including an apparatus and a transfer device for transferring the toner image onto a recording paper, 13 is a paper feed unit provided in the main body unit 11, and 14 is a paper feed unit 13. On the opposite side, a paper discharge unit provided side by side with the main body unit 11, 15 is a duplex transport unit mounted on the main body unit 11 so as to be openable and closable, and 16 is a duplex reversing unit mounted on the paper feed unit 13. Although the present embodiment exemplifies the case where the duplex reversing unit 16 is placed on the paper feeding unit 13, it goes without saying that the duplex reversing unit 16 can be placed on the main body unit 11 together with the duplex transport unit 15. is there. The main body unit 11 is connected to the paper feed port 51 of the paper feed unit 13 and has a recording paper receiving port 21 provided with a recording paper rear edge detection sensor 61.
And a pair of upper and lower feed rollers that sequentially convey the recording papers one by one from the recording paper inlet 21 and send them to the image forming mechanism 12.
22, an image forming mechanism 12 for forming an image on recording paper, and a conveyance path switching gate for conveying the recording paper on which the image is formed to the paper discharge unit 14 or the duplex conveyance unit 15.
23 and. As shown in FIGS. 2 and 3, the image forming mechanism 12 has an organic photoreceptor layer formed on its surface and a transfer device.
A photoconductor 25 that rotates in synchronization with the photoconductor 31, an exposure device 27 including a charger 26 provided below the photoconductor 25, and an LED light emitting element array, and an electrostatic latent image formed by the exposure device 27 are developed. To form a toner image, a toner concentration sensor 29, a transfer belt having a charger 30, and a transfer device 31 having four rollers for driving the transfer belt, and an image transferred by the transfer device 31. A fixing device 32 for fixing the transferred toner image on the recording paper, a neutralizer 33 for neutralizing the surface of the photoconductor 25 after the toner image is transferred onto the recording paper, and a cleaning cleaner 34 are provided. The exposure device 27 includes an LED light emitting element array,
The photoconductor 25 is irradiated with light via the lens system 35. The transfer device 31 having a transfer belt applies a predetermined electric charge to the endless transfer belt 36 by a charger 30 provided in a stage before the position where the photoconductor 25 is contacted, and the feed roller 22 is provided on the lower surface of the transfer belt 36. The toner image on the photoconductor 25 is transferred onto the recording paper at the portion of the transfer roller 37 installed in the transfer belt 36 while adsorbing the recording paper conveyed from the photoconductor 25 onto the recording paper. The transfer device 31 includes a plurality of rollers 38 around which the transfer belt 36 is endlessly wound, an upper feed roller 22 ′, and timing of an upper portion of a timing roller 39 provided between the feed roller 22 and the transfer belt 36. And a housing 40 for supporting each of the rollers 39 '. The recording paper to be transferred is sent between the feed rollers 22 and 22 ', the timing rollers 39 and 39', and the transfer belt 36 and the backup roller 36 '. The housing 40 has a feed roller 22 'at one end pivotally attached to the main unit 11, and a timing roller 39 and a backup roller 36' at the lower portion can be left, so that the housing 40 can be swung upward along the conveyance path of the recording paper. When the housing 40 is opened together with the static eliminator 33 that is rotatable in the opposite direction to open the upper space above the photoconductor 25, the photoconductor 25 can be replaced and jammed. Next, the sheet feeding unit 13 provided adjacent to the recording sheet receiving port 21 side of the main body unit 11 has sheet feeding trays 41 and 42 for storing recording sheets of different sizes and a sheet feeding tray 43 for storing a large amount of recording sheets. A paper feed unit 45 that is set up and down and feeds recording paper by the paper feed roller 44, and a paper feed port 51 that feeds the recording paper taken out by the paper feed roller 44 to the recording paper reception port 21 of the main unit 11. And paper feed paths 52, 53, 54 for concentrating the recording paper supplied from the paper feed trays 41, 42, 43 into the paper feed port 51. Reference numeral 55 is a conveyance path for feeding the recording paper from the duplex reversing unit 16 to the paper feed port 51. The above conveyance path 52,53
Are configured to have the same transport distance. Duplex transport unit 15 mounted on the main unit 11
Jam can be easily cleared by opening and closing it so that it can be rotated toward the back. Further, the duplex transport unit 15 can be separated into an upper unit 15a and a lower unit 15b with a recording sheet transport unit as a boundary, and each unit can be rotated rearward and openable. The duplex transport unit 15 switches the transport path switching gate 23 so as to block the transport path for the recording sheet on which the image is formed in the image forming mechanism 12 to the paper discharge unit 14, and the reverse of the inside of the main unit 11. The recording paper is conveyed in the direction. Although not shown, the duplex transport unit 15 is provided with a transport mechanism that is driven and controlled by the controller of the image forming apparatus. The duplex reversing unit 16 that is mounted on the paper feeding unit 13 and is also openable and closable toward the back to facilitate jam processing can be opened and closed independently of the duplex transport unit 15. It is configured to be able to. Further, the duplex reversing unit 16 can also be separated into an upper unit 16a and a lower unit 16b with the recording paper transporting unit as a boundary, and each unit can be opened and closed so as to be rotatable rearward. Then, the transport path switching gate 62 provided in the vicinity of the duplex transport section 15 is switched to accept the recording sheet transported from the duplex transport section 15 or send it to the transport path 55 of the sheet feeding unit 13. There is. Although not shown, the duplex reversing unit 16 is also provided with a transport mechanism that is driven and controlled by the controller of the image forming apparatus. On the opposite side of the paper feeding unit 13, the main unit 11
The paper discharge unit 14 provided side by side with the paper discharge roller 63 that takes out the recording paper from the main body unit 11 and lowers the recording paper by a predetermined number to accommodate the recording paper, and when the accommodated recording paper becomes empty, the initial position is set. It is equipped with a paper discharge stocker 64 that rises up to. <Operation> Regarding the operation of the LED printer configured as described above,
A case of single-sided printing will be described as an example. In FIG. 1, the photoconductor 25, the fixing roller of the fixing device 32, the transfer device 31 and the transfer belt 36 rotate in the directions of the arrows. The transfer belt 36 contacts the upper surface of the photoconductor 25,
It is rotating in synchronization with. First, the surface of the photoconductor 25 is charged by the charger 26. Next, exposure is performed by an exposure device 27 including an LED light emitting element array. At this time, the LED light emitting element array is modulated according to the image signal, and exposure is performed according to a predetermined image signal in combination with the rotation of the photoconductor 25, and the surface of the photoconductor 25 is subjected to static exposure according to the image signal. A latent image is formed. By the rotation of the photoconductor 25, the electrostatic latent image is developed in the developing device 28, and a toner image is formed on the surface of the photoconductor 25. On the other hand, the recording paper on which the image is transferred is supplied from the paper feed trays 41, 42 and 43 into the main body unit 11 by the paper feed roller 44, and is conveyed through the conveyance path by the feed roller 22 to the timing rollers 39, 39 ′. Then, the sheets are registered, and the sheets are indexed one by one and fed to the lower surface of the transfer belt 36. At this time, since the transfer belt 36 is charged by the charger 30, the recording paper is conveyed while being attracted to the lower surface of the transfer belt 36, comes into contact with the upper surface of the photoconductor 25, and the toner image on the surface of the photoconductor 25 is formed. Transcribed. When the recording paper is further fed, the roller 38 at the end of the transfer device 31 is
The recording paper is peeled off from the transfer device 31 due to its rigidity in the section, and is conveyed to the fixing device 32 to fix the toner image,
The paper is taken out from the main body unit 11 by the paper discharge roller 63 and is put into the paper discharge stocker 64. On the other hand, the toner remaining on the surface of the photoconductor 25 after the toner image is transferred onto the recording paper is neutralized by the static eliminator 33 and cleaned by the cleaner 34, and one cycle is completed. Next, the case of double-sided printing will be described. Fixing device 32
In this case, the recording paper that has been conveyed to and fixed with the toner image
By switching the transport path switching gate 23 to block the transport path to the paper discharge unit 14, the duplex transport section
It is sent to 15, and is conveyed in the opposite direction to the inside of the main unit 11. The recording paper transported from the duplex transport unit 15 to the duplex reversing unit 16 via the transport path switching gate 62 is switched to the switchback type by switching the transport path switching gate 62 so as to form a transport path to the paper feeding unit 13. After that, it is fed from the transport path 55 to the paper feed port 51. Subsequent processing is the same as in the case of the above-mentioned one-sided printing, and is finally put into the paper discharge stocker 64. The operation of the LED printer configured as described above will be described below with reference to FIGS. 4 and 5. That is, in FIG. 4, the upper units 15a and 16a of the duplex conveying unit 15 and the duplex reversing unit 16 are respectively shown.
Is opened by rotating toward the back, and the conveyance path of the recording paper is opened so that maintenance such as jam processing and parts replacement can be appropriately performed. Next is the fifth
In the figure, the upper and lower units 15a of the duplex transport unit 15 are
15b is opened by rotating toward the back,
The upper unit 16a of the duplex reversing unit 16 is also opened by rotating backward. Further, the housing 40 is also opened by swinging upward along the conveyance direction of the recording paper. By opening the photoconductor 25 in this manner, it is possible to perform a jam treatment around the transfer portion or the photoconductor 25, or to replace the photoconductor 25. In any case, each of the duplex transport unit 15 and the duplex reversing unit 16 can be opened and closed independently, and each of the duplex transport unit 15 and the duplex reversing unit 16 has a recording paper transport unit as a boundary. Since the upper unit 15a, 16a and the lower unit 15b, 16b can be separated from each other, it is very easy to remove the recording paper when the recording paper is jammed in the image forming mechanism 12. Note that the image forming mechanism 12 has a built-in control mechanism, detects the open / close state of the duplex transport unit 15 and the duplex reversing unit 16, and transports the recording paper to the duplex transport unit 15 and the duplex reversing unit 16, or records. It is designed to control the ejection of paper.

[Effects of the embodiment]

According to the above-described embodiment, since the duplex reversing unit 16 is arranged above the paper feeding unit 13, the paper feeding unit 13 and the transportation paths 52, 53, 54 are used to collect the transportation path 55. The feed roller 22 of the unit 11 can be shared, and the main body unit 11 can be downsized. In addition, since the duplex transport unit 15 and the duplex reversing unit 16 are arranged above the main unit 11, by opening them, each device unit that becomes an obstacle during maintenance such as jam processing and removal of the photoconductor is temporarily eliminated. You can do that, making them easier to work with. Further, since the paper conveyance path is arranged close to the straight path, it is possible to prevent the occurrence of jams without giving frustration to the paper and reliably convey the recording paper. Further, since the duplex transport section and the reversing section are separated, each unit is downsized and operability is improved,
The space required for opening is also small.

【The invention's effect】

As described above, the image forming apparatus of the present invention is provided with the duplex conveying section and the reversing section above the main body unit, and can be opened and closed in the direction perpendicular to the recording sheet conveying direction. Even if it occurs, the paper transport path is completely opened, so that the jammed recording paper can be taken out easily, and the processing operation can be performed easily and quickly, so that the operation speed of the image forming apparatus can be increased. In addition, the space required for opening the duplex transport unit and the reversing unit is small, and the apparatus body can be downsized. Furthermore, since the duplex transport unit and the reversing unit can be opened and closed independently of each other, it is possible to provide an image forming apparatus with improved operability.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the overall structure of the image forming apparatus of the present invention, FIG. 2 is a schematic diagram showing the internal structure of the main body unit, and FIG. 3 is an internal structure of the main body unit with the housing of the transfer device being opened. FIG. 4 and FIG. 5 are schematic perspective views of the state in which the duplex conveying unit and the reversing unit are opened. 11 …… Main unit 12 …… Image forming mechanism 13 …… Paper feeding unit 14 …… Paper discharging unit 15 …… Duplex transport section 15a …… Upper unit 15b …… Lower unit 16 …… Duplex reversing section 16a …… Upper unit 16b …… Lower unit 31 …… Transfer device 40 …… Housing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Umezawa 3167 Yamamiya-cho, Kofu-shi, Yamanashi Japan Precision Engineering Co., Ltd. (72) Inventor Koichi Sugihara 3167 Yamamiya-cho, Kofu-shi, Yamanashi Nippon Precision Engineering Co., Ltd. (72) Inventor Yusuke Asao 3167 Yamamiya-cho, Kofu-shi, Yamanashi Japan Precision Engineering Co., Ltd. (72) Inventor Saegusa Hajime 3167 Yamamiya-cho, Kofu-shi Yamanashi Prefecture Japan Precision Engineering Co., Ltd. (72) Inventor Tetsuya Aiyama 3167 Yamamiya-cho, Kofu-shi, Yamanashi Japan Precision Engineering Co., Ltd. (56) Reference JP 63-112348 (JP, A) JP 61-114936 (JP, A) JP 59- 150772 (JP, A)

Claims (3)

[Claims] 1. An electrostatic latent image formed by exposing a photoconductor, a paper conveyance path located between the photoconductor and a transfer means for the paper formed on the photoconductor so as to be opened and closed, and exposing the photoconductor. A main body unit provided with an exposing means for forming a toner image, a developing means for developing the electrostatic latent image to form a toner image, and a transfer means for transferring the toner image onto a recording medium, and a main unit attached to the main body unit. And a paper feed unit for feeding the recording medium to the main body unit, and above the main body unit, a duplex transport unit for receiving and transporting the paper from the paper transport path, and a duplex transport unit for transporting the paper. The duplex reversing unit that receives the received sheet, reverses the sheet, and conveys the sheet to the sheet conveying path of the main body unit is provided independently of each other. The transport unit and the duplex reversing unit are each composed of an upper unit and a lower unit that are separated from each other by the sheet transport path.The duplex transport unit is attached to the main unit so that it can be opened and closed, and the duplex transport unit is open. By opening the sheet transfer means of the main body unit, the image forming apparatus can also open the sheet conveying path. 2. The image forming apparatus according to claim 1, wherein the duplex reversing unit is arranged on the paper feeding unit. 3. A duplex conveying unit and a duplex reversing unit can be opened and closed by a rotating shaft that is parallel to the sheet conveying direction, and the transfer means can be opened and closed by a rotating shaft that is orthogonal to the sheet conveying direction. The image forming apparatus according to item 1.