JP4622374B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine or a printer that employs an electrophotographic system, an electrostatic recording system, or the like, and in particular, records after an image formed on an image carrier is once transferred to an intermediate transfer body. The present invention relates to an improvement in an intermediate transfer type image forming apparatus that performs batch transfer onto a material.

Conventionally, as this type of intermediate transfer type image forming apparatus, each color component toner image formed on a photosensitive member or the like is sequentially primary transferred to an intermediate transfer body, and the multicolor toner image on the intermediate transfer body is transferred to a secondary transfer apparatus. Are known to be collectively transferred onto paper. In addition, in such a color image forming apparatus, in recent years, there is a great demand for speeding up, downsizing, and energy saving.
For speeding up, a tandem configuration in which the image forming units for each color are arranged in parallel on the intermediate transfer belt is effective. However, the image forming units are arranged in parallel and a fixing device is arranged on the extension. The configuration described above has a problem that the apparatus becomes large.

Japanese Patent No. 3470696 (Embodiment of the Invention, FIG. 1) JP-A-4-274264 (Example, FIG. 1)

  As countermeasures against the enlargement of the apparatus, for example, as shown in FIG. 9, the intermediate transfer belt 201 is disposed obliquely, the image forming units 202 (202a to 202d) are shortened and arranged in parallel, and the intermediate transfer is performed. By arranging a fixing device 204 with a heat reflecting plate (not shown) and an exhaust device (not shown) below the belt 201, a configuration of a downsized device has been proposed (see, for example, Patent Document 1). ).

However, in such a configuration, the toner images formed on the intermediate transfer belt 201 by the image forming units 202 (202a to 202d) are devised by devising the arrangement of the batch transfer unit 203 and the fixing device 204. In some cases, the image is quickly transferred onto a sheet (by the batch transfer unit 203), and the image blur and the increase in size of the apparatus due to the scattering of the toner image on the intermediate transfer belt 201 are solved. Since (202a to 202d) are arranged on the upper portion of the intermediate transfer belt 201, if the toner floats due to development or the like, there is a concern that the intermediate transfer belt 201 may be directly affected or cause in-machine contamination. Further, since the heat of the fixing device 204 is discharged outside the apparatus by the exhaust device, there is no concern that the heat of the fixing device 204 immediately affects the image formation, but it is difficult to say that the energy efficiency of the fixing device 204 is good. Further, when the apparatus is used for a long time with this configuration, the heat of the fixing device 204 affects the upper image forming unit 202, and there is a concern that image defects may be caused.
In addition, in such a configuration, the sheet tray is generally disposed below each image forming unit 202 (202a to 202d) because the sheet is necessarily passed through the lower batch transfer unit 203. When replenishing paper to the tray, it is not necessary to squat down or bend the back, and it is difficult to say that it is a user-friendly device.

  On the other hand, from the viewpoint of operability, a configuration in which the paper tray is disposed above is proposed in, for example, Patent Document 2, but in this case, the paper transport path is a so-called “S-shape”, and the paper operation starts from the printing operation. There is a problem that it takes a long time to discharge. Further, since the paper discharge is normally performed at the lower part of the apparatus, the operability of taking out the paper from the discharge tray is worsened.

  The present invention has been made in order to solve the technical problems as described above, and is capable of high speed, small size, high image quality, energy saving and operability, and easy jam processing around the fixing device. An object of the present invention is to provide an image forming apparatus.

That is, as shown in FIGS. 1A and 1B, the basic configuration of the present invention includes an image forming engine 1 that forms a toner image and transfers the toner image onto a recording material at a transfer portion, and the image forming engine 1. A recording material supply unit 2 a is provided above the engine 1 so that recording material can be supplied, and a conveyance path 2 b of the recording material supplied from the recording material supply unit 2 a passes through a transfer site with the image forming engine 1. After that, the recording material transport system 2 is disposed so as to cross between the image forming engine 1 and the recording material supply unit 2a, and stores and discharges the recording material in the recording material discharge unit 2c through the transport path 2b, and the image forming engine. 1 and a recording material supply unit 2a, and a fixing device 3 for fixing a toner image transferred to the recording material at a transfer portion of the image forming engine 1, and a recording material positioned before and after the fixing device 3. So that it can be separated with the transport path 2b as the boundary. Is characterized in further comprising a moving mechanism 6 of the upper movable unit 4 is moved away from the unit opposite to include Kutomo recording material supply portion 2a.

In such technical means, the image forming engine 1 that is the subject of the present application is not particularly limited in the method of forming an image, and an image forming method such as an electrophotographic method or an electrostatic recording method may be appropriately selected. Moreover, either color or monochrome may be used.
Here, the image forming engine 1 in the present invention includes an image forming unit that forms and supports a toner image, and an intermediate transfer member that temporarily conveys and holds the toner image from the image forming unit. If the portion is arranged below the intermediate transfer member, it is possible to prevent in-machine contamination due to toner floating or the like in the image forming portion. Further, the distance from the image forming unit to the transfer site can be shortened, the toner image holding time on the intermediate transfer member can be shortened, toner scattering from the intermediate transfer member can be suppressed, and the image quality can be improved. Further, the intermediate transfer member may be either a belt shape or a drum shape, but a belt shape is preferable from the viewpoint of freedom of layout and miniaturization. The image forming unit includes an image carrier that forms a toner image, and the number thereof is not particularly limited. However, when configuring a color image forming apparatus, it may be configured in a tandem type from the viewpoint of speed and the like. preferable.

  Furthermore, the recording material supply unit 2a is only required to be disposed at least above, and the number thereof is not particularly limited. For example, another recording material supply unit 2a is disposed below the image forming engine 1 or the like. There is no problem. As described above, in the present invention, since the recording material supply unit 2a is provided on the upper side, an image forming apparatus that can be operated in an easy posture when replenishing the recording material to the recording material supply unit 2a, that is, a user-friendly image forming apparatus. It becomes possible. For example, an image reading device or the like may be mounted above the recording material supply unit 2 a disposed above the image forming engine 1.

The recording material conveyance system 2 in the present invention includes a recording material supply unit 2a, a recording material discharge unit 2c, and a recording material conveyance path 2b for conveying the recording material from the recording material supply unit 2a to the recording material discharge unit 2c. The Here, the conveyance path 2b of the recording material means a path for conveying the recording material, and is usually partitioned by a conveyance guide member, and for example, conveyance members such as a roll pair and a recording material conveyance belt are appropriately disposed.
Further, the arrangement position of the recording material discharge portion 2c in the present invention is not particularly limited, and may be a position where the recording material conveyed through the recording material conveyance path 2b is accommodated and discharged. It may be disposed in any of the units 5, and may be disposed across the upper movable unit 4 and the lower unit 5.

The fixing device 3 according to the present invention includes a heating unit for fixing the toner image. The heating unit may be a contact heating system, a non-contact heating system, or the like, for example, an electromagnetic induction heating system. And so on.
Furthermore, in the present invention, the fixing device 3 can be disposed closer to the center of the image forming apparatus, so that direct influence from the external environment of the apparatus can be prevented, and thermal efficiency is improved. If a heat shield member is provided around the fixing device 3, it is possible to prevent discharge of excess thermal energy from the fixing device 3, and the thermal efficiency is further improved. Therefore, energy saving is possible.

The moving mechanism 6 in the basic configuration of the present invention includes an upper movable unit including at least the recording material supply unit 2a so that the moving mechanism 6 can be separated with the recording material conveyance path 2b positioned before and after the fixing device 3 as a boundary. 4 is moved away from the opposing unit (for example, the lower unit 5), and the moving direction is not limited as long as it is upward, and may be parallelly moved vertically upward. It does not matter even if it is a moving mode. Thereby, the jam processing property around the fixing device 3 is improved. At this time, the upper movable unit 4 does not have to be the entire upper portion of the apparatus, and even if a part of the upper movable unit 4 is movable, it may be an aspect that improves the jam handling property.

The moving mechanism 6 is not particularly limited as long as it moves the above-described upper movable unit 4. For example, a mechanical moving method using a hinge structure using a spring, an electric motor, or the like is used. Thus, a method of electrically moving them, a combination thereof, or the like is appropriately used.
Further, it is preferable that a part of the fixing device 3 is moved as the moving mechanism 6 in accordance with the movement of the upper movable unit 4 including at least the recording material supply unit 2a described above. Space can be secured, and the recording material when jammed by the fixing device 3 can be more easily removed. When a part of the fixing device 3 is moved, it is desirable to take care that the user does not directly touch the heated part of the fixing device 3 that has been opened.

Then, as the mode of the image forming apparatus according to the present invention has a as follows.
That is, the present invention is, as shown in FIG. 1 (b), the image forming engine 1 for transferring a toner image on a recording material in the formed and transfer portion of the toner image, the recording material above the image generating engine 1 And a recording material supply unit 2a in which the recording material can be supplied, and the recording material conveyance path 2b supplied from the recording material supply unit 2a passes through a transfer site with the imaging engine 1 and A recording material conveyance system 2, which is disposed so as to cross between the recording material supply unit 2a and accommodates and discharges the recording material in the recording material discharge unit 2c through the conveyance path 2b, the image forming engine 1, and the recording material supply unit 2a. And a fixing device 3 for fixing the toner image transferred to the recording material at the transfer site of the image forming engine 1 and a recording material conveyance path 2b positioned before and after the fixing device 3 as a boundary. At least recording material supply so that it can be separated The first movable mechanism 7 that moves the upper movable unit 4 including the portion 2a away from the opposing unit and the recording material conveyance path 2b positioned before and after the fixing device 3 can be separated as a boundary. And a second moving mechanism 8 for moving the lower movable unit 5a including at least the image forming engine 1 away from the opposing unit , and the first and second moving mechanisms 7 and 8 have a vertical center of the apparatus. a rotation shaft 9 in opposite positions across the line, allowed pivot the upper movable unit 4 and the lower movable unit 5a in the direction both away and said Rukoto.

In this way, if the first and second moving mechanisms 7 and 8 are provided and the upper movable unit 4 and the lower movable unit 5a are moved away from each other, a larger space can be secured, jam handling performance, etc. Will improve. At this time, the moving direction of the upper movable unit 4 may be a direction away from the opposing unit (for example, the lower unit 5), and examples thereof include a mode of linearly moving upward and a mode of rotating upward. In addition, the moving direction of the lower movable unit 5a may be a direction away from the opposing unit (for example, the upper movable unit 4), and includes a mode of linearly moving downward and a mode of rotating. From the viewpoint of downsizing, a rotating mode is preferable.
Therefore, in this invention, the 1st and 2nd moving mechanisms 7 and 8 are equipped with the rotation support shaft 9 in the position which opposes on both sides of the center line of the perpendicular direction of an apparatus, and the upper side movable unit 4 and the lower side movable unit The 5a is rotated in a direction away from each other, and a larger space can be effectively secured. For this reason, the jam handling property and the like are further improved.

According to the basic configuration of the present invention, the recording material supply unit is provided above the image forming engine, and after the recording material transport path supplied from the recording material supply unit passes through the transfer portion with the image forming engine. A recording material conveyance system that is disposed across the image forming engine and the recording material supply unit, and that accommodates and discharges the recording material in the recording material discharge unit through the conveyance path; and the image forming engine and the recording material supply unit. The upper movable unit including at least the recording material supply unit is moved away from the opposing unit so as to be separable with a fixing device provided therebetween and a recording material conveyance path positioned before and after the fixing device as a boundary. Since it is equipped with a moving mechanism, high speed, small size, energy saving and operability are taken into consideration, and even if a recording material jam occurs around the fixing device, a sufficient space can be secured and jam handling performance can be secured. Maintenance and the like can be improved.
Further , according to the present invention, the upper movable unit including at least the recording material supply unit is moved away from the opposing unit so as to be separable with the recording material conveyance path positioned before and after the fixing device as a boundary. A second moving unit that moves the lower movable unit including at least the image forming engine away from the opposing unit so that the first moving mechanism and the recording material conveyance path positioned before and after the fixing device can be separated. The first and second moving mechanisms have a rotation support shaft at a position opposite to each other across the vertical center line of the apparatus, and separate the upper movable unit and the lower movable unit from each other. since the so that allowed rotatable in the directions, an upper movable unit and the lower movable unit can be moved so as to separate from each other, of that amount, the recording material in the fixing device around jam It is possible to ensure a wider working space for the management and maintenance. For this reason, high speed, small size, energy saving and operability are taken into consideration, and a sufficient space can be secured even if a jam of the recording material occurs around the fixing device, and the jam handling property and maintainability are improved. .

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
Embodiment 1
FIG. 2 is a schematic diagram showing Embodiment 1 of the image forming apparatus to which the basic configuration of the present invention is applied.
In FIG. 1, an image forming apparatus 10 includes an upper unit 10a including a one-stage paper tray 51 for supplying paper as a recording material above the apparatus, an image forming engine 20 for forming a toner image below the apparatus, and a two-stage image forming engine. The lower unit 10b including the paper trays 52 and 53 is configured.
Between the upper paper tray 51 and the lower paper tray 52, the fixing device 40 for fixing the toner image on the paper and the image forming engine 20 are arranged in this order from the upper side.
Further, the image forming apparatus 10 of the present embodiment has a manual feed tray 54 that allows manual paper feed to the side of the apparatus, and a paper discharge tray 55 that accommodates the paper on which image formation has been completed on the paper tray 51. There are provided various paper transport paths for transporting paper from the paper trays 51 to 53 and the manual feed tray 54 to the paper discharge tray 55.

The image forming engine 20 in the present embodiment has four image forming units 21 (21a to 21a) that form four color component toner images (in this embodiment, yellow, magenta, cyan, and black) by, for example, electrophotography. 21d) and an intermediate transfer belt 30 that sequentially transfers (primary transfer) each color component toner image formed by each image forming unit 21 and holds it.
Each image forming unit 21 (21a to 21d) has a photosensitive drum 22 around each photosensitive drum 22, a charging device 23 such as a charging roll for charging the photosensitive drum 22, and a charged photosensitive drum. An exposure device 24 such as a laser scanner that writes an electrostatic latent image on the photoconductive drum 22, a developing device 25 that develops the electrostatic latent image written on the photoconductive drum 22 with each color component toner, and a photoconductive drum 22 A primary transfer roll 26 such as a transfer roll for transferring the toner image onto the intermediate transfer belt 30 and a drum cleaner 27 for removing residual toner on the photosensitive drum 22 are provided.
Reference numeral 28 (28a to 28d) denotes a toner replenishing device that replenishes each color toner to the developing device 25, and replenishes toner to each developing device 25 from a replenishing port 29 via a transport pipe (not shown). It has become.

The intermediate transfer belt 30 is composed of an endless belt in which, for example, conductive carbon black is kneaded with polyimide resin and the volume resistivity is about 10 ⁹ to 10 ¹² Ω · cm. For example, the tension roll 32 is used as a drive roll, and the tension roll 33 is used as a tension roll. Reference numeral 34 denotes a belt cleaner that cleans residual toner and the like on the intermediate transfer belt 30.
In the present embodiment, by placing the stretching roll 32 obliquely below the stretching roll 31, the intermediate transfer belt 30 can be disposed obliquely, contributing to downsizing of the image forming apparatus 10.
Further, by disposing the image forming unit 21 below the intermediate transfer belt 30 (between the stretching roll 32 and the stretching roll 33), the inside of the image forming unit 21 is contaminated due to, for example, toner floating from the developing device 25. Therefore, it is possible to prevent image quality deterioration caused by the image quality and to form an image with more stable image quality.

  In the present exemplary embodiment, a secondary transfer roll 35 that collectively transfers the toner images transferred onto the intermediate transfer belt 30 onto a sheet is provided at a position facing the stretching roll 31 of the intermediate transfer belt 30. A secondary transfer bias (not shown) is applied using the tension roll 31 as a backup roll.

The fixing device 40 according to the present embodiment is provided in a substantially horizontal direction with the secondary transfer roll 35 on the downstream side of the secondary transfer roll 35. As shown in FIG. 3, the fixing device 40 includes an upper fixing unit 40a and a lower fixing unit 40b. It is configured. The upper fixing unit 40a includes a pressure roll 41 and a heat insulating cover 44 provided so as to cover the pressure roll 41, and the lower fixing unit 40b includes a heating roll 42 in which a heater 43 is disposed, and the heating roll. The heat insulating cover 45 is provided so as to cover 42.
The heat shield covers 44 and 45 are each provided with a metal heat radiation plate 46 on the side of the pressure roll 41 and the heating roll 42, the outside is covered with a vacuum heat insulating material 47, and the exterior is further covered with a plastic exterior cover 48. The covered structure is adopted.

Here, as the heat radiation plate 46, for example, a mirror-finished metal such as aluminum is used, and by making the surface a radiation rate of 0.5 or less, the reflectance on the surface is increased. Moreover, the vacuum heat insulating material 47 is comprised by what provided the member whose heat conductivity is 0.03 W / (m * K) or less thickness 3mm or more, for example. Furthermore, the exterior cover 48 is made of a plastic having a low thermal conductivity.
Further, in the present embodiment, the pressure roll 41 and the heating roll 42 and the respective heat shield covers 44 and 45 are arranged with a distance of, for example, 3 to 20 mm, and the heat shield covers 44 and 45 are the pressure rolls. 41 and the heating roll 42 are sandwiched from above and below. Therefore, the heat from the heating roll 42 does not leak excessively outside the fixing device 40. Further, in the present embodiment, a cooling plate 49 is provided on the downstream side of the fixing device 40 to reduce the temperature of the paper after being fixed by the fixing device 40 so as to promote solidification of the fixed toner. It has become.
Since the pressure roll 41 and the heating roll 42 are opposed to each other in the vertical direction, the sheet moves in the nip area in the substantially horizontal direction.

  In the present embodiment, the toner image on the intermediate transfer belt 30 is transferred to the lower surface side (vertically below) of the sheet by the secondary transfer roll 35, and therefore, between the secondary transfer roll 35 and the fixing device 40. Is provided with a transport device 37 for transporting the paper while holding the paper upward. As the conveying device 37, an electrostatic adsorption method or an air suction method can be used, and image quality deterioration of unfixed toner transferred onto the paper by the secondary transfer roll 35 is prevented.

Next, the paper transport system in the present embodiment will be described with reference to FIG.
The paper trays 51 to 53 are pulled out from the front side of the image forming apparatus 10 to replenish paper. In particular, when the upper paper tray 51 is used, it can be performed in an easy posture. ing.
Each of the paper trays 51 to 53 is provided with a separating mechanism 56 for feeding the paper one by one. Therefore, the sheet fed by the pickup roll 56a is turned by the action of the feed roll 56b and the retard roll 56c, and only the uppermost sheet is fed out.

Further, as a transport path for transporting paper fed from the paper trays 51 to 53 and the manual feed tray 54, a first transport path 61 extending downward from the paper tray 51 and a second transport extending upward from the paper trays 52 and 53. A third conveyance path 63 extending in a substantially horizontal direction from the path 62 and the manual feed tray 54 is provided, and these conveyance paths 61 to 63 are guided to a registration roll 71 that performs sheet alignment on the upstream side of the secondary transfer roll 35. It is burned.
A main conveyance path 64 extending substantially horizontally from the registration roll 71 through the secondary transfer roll 35 and the fixing device 40 is provided, and a paper discharge tray is bordered by a conveyance roll 74 provided on the downstream side of the fixing device 40. It extends upward to a discharge roll 72 for discharging the paper to 55. Reference numeral 73 denotes a second discharge roll, for example, for conveying paper to a post-processing apparatus (not shown).

  Further, a reversing roll 75 capable of reversing and transporting the paper is provided in the middle of the main transport path 64, and the reversing roll 75 is driven to reverse at a predetermined timing with respect to the paper transported through the main transport path 64. In addition, the sheet is conveyed to the reverse conveyance path 65 side. Therefore, the sheet conveyed to the reversal conveyance path 65 is conveyed to the registration roll 71 through a plurality of conveyance rolls, and newly transferred to the surface opposite to the surface on which the toner image has been transferred by the secondary transfer roll 35. A correct toner image is formed.

  In particular, the image forming apparatus 10 according to the present embodiment is divided into the upper unit 10a and the lower unit 10b with a substantially horizontal portion of the main transport path 64 from the registration roll 71 to the transport roll 74 as a boundary. I know. Further, a rotation support shaft A as a moving mechanism in the present embodiment is provided at a position near the manual feed tray 54 of the upper unit 10a, and the upper unit 10a with the paper tray 51 and the discharge tray 55 is connected to the upper unit 10a. It is lifted upward (rotates) around the pivot axis A.

Next, a basic image forming process of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG.
Now, when image data of each color component image (yellow, magenta, cyan, black) is sent to the exposure device 24 of each image forming unit 21 (21a to 21d), it is transferred onto the photosensitive drum 22 of each image forming unit 21. An electrostatic latent image is formed for each color component, and the electrostatic latent image is visualized by the developing device 25 containing the corresponding color toner, and each color unfixed toner image is formed on the photosensitive drum 22. It is formed.
The unfixed toner images of the respective colors are sequentially primary-transferred onto the intermediate transfer belt 30 by the primary transfer roll 26 at the primary transfer portion where the photosensitive drums 22 and the intermediate transfer belt 30 are in contact with each other, and are overlaid with colors.

The unfixed toner image primarily transferred onto the intermediate transfer belt 30 in this way is moved to the secondary transfer position (comprised of the secondary transfer roll 35 and the stretching roll 31) as the intermediate transfer belt 30 moves. Move to.
Here, assuming that a sheet is fed from the sheet tray 51, the following sheet conveyance will be described.
Only one sheet fed from the sheet tray 51 by the separation mechanism 56 is conveyed through the first conveyance path 61. The sheet transported through the first transport path 61 is aligned by the registration roll 71 and transported to the secondary transfer position, and the unfixed toner image on the intermediate transfer belt 30 is collectively transferred (secondary transfer) by the secondary transfer roll 35. Transferred).
The sheet on which the unfixed toner images are collectively transferred is sucked and conveyed by the conveying device 37 and conveyed to the fixing device 40, and the unfixed toner image is fixed.
The sheet that has passed through the fixing device 40 is conveyed to the discharge roll 72 via the conveyance roll 74 and the reverse roll 75, and is discharged to the discharge tray 55 in a face-up state (toner image is upward).

For example, when the paper is jammed in the main conveyance path 64, the upper unit 10a of the image forming apparatus 10 is lifted around the rotation support shaft A, and a space is formed between the upper unit 10a and the lower unit 10b. Secure.
FIG. 4 is a schematic diagram showing a state when the upper unit 10a and the lower unit 10b of the image forming apparatus 10 according to the present embodiment are opened. In the present embodiment, particularly the horizontal portion (from the registration roll 71 to the conveyance roll 74) of the main conveyance path 64 is opened, and the upper roll 71a of the registration roll 71, the secondary transfer roll 35, and the upper roll 74a of the conveyance roll 74 are It moves with the upper unit 10a. Further, the lower roll 71b of the resist roll 71 and the lower roll 74b of the transport roll 74 remain on the lower unit 10b side. Although not shown, the transport device 37 and the cooling plate 49 before and after the fixing device 40 are moved in accordance with the movement on the upper unit 10a side.
In the present embodiment, the fixing device 40 remains on the lower unit 10b side.

Therefore, when the paper conveyance path before and after the fixing device 40 is opened and the paper is jammed around the fixing device 40, the jammed paper can be easily confirmed and can be easily removed.
Therefore, as in the present embodiment, it is easy to remove a paper jam from the fixing device 40 disposed substantially at the center of the image forming apparatus 10, and paper jams from batch transfer, fixing, and paper discharge to the upper unit 10a. Therefore, it is possible to provide the image forming apparatus 10 with excellent jam handling operability.

In order to evaluate the performance of the image forming apparatus 10 according to the present embodiment, the following comparison is made.
FIG. 5 is a schematic diagram showing a comparative form of the image forming apparatus according to the present embodiment. The basic configuration of the image forming apparatus 10 in this comparative embodiment is substantially the same as that of the first embodiment (see FIG. 2), but there is no upper unit moving mechanism, and only the image forming engine 20 moves downward. This is different from the first embodiment in that a moving mechanism is provided. In the figure, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the figure, in the image forming apparatus 10 according to this comparative embodiment, the image forming engine 20 moves downward (in the direction of arrow C in the figure) by the rotation fulcrum 100 that is obliquely below the image forming engine 20, so that jam handling performance is improved. And maintainability.
With such a configuration, when a paper jam occurs around the fixing device 40, the lower part of the main conveyance path 64 is opened by the movement of the image forming engine 20, but this is insufficient to secure a space for jam processing and maintenance. It is.
Further, when the lower fixing unit 40 b of the fixing device 40 is moved downward integrally with the image forming engine 20, the toner replenishing device 28 or the toner disposed on the intermediate transfer belt 30 in the image forming engine 20 is used. Since it interferes with a toner replenishment path (not shown) from the replenishing device 28 to the developing device 25, the main conveyance path 64 before and after the fixing device 40 cannot be sufficiently opened, and jam handling and maintenance are insufficient. To do.
Therefore, it is understood that a sufficient space can be secured if at least the upper unit 10a (see FIG. 4) of the image forming apparatus 10 is opened as in the present embodiment.

As described above, according to the present exemplary embodiment, even when the fixing device 40 is disposed near the center of the image forming apparatus 10, a paper jam can be easily removed. Further, it can be easily performed when maintenance or the like is required.
Furthermore, by providing the paper tray on the upper side, a “person-friendly” configuration is possible without taking an unreasonable posture when replenishing paper.
Further, since the fixing device 40, the intermediate transfer belt 30, and the image forming unit 21 are arranged in this order from the top, stable image formation is possible without being affected by heat from the fixing device, and the toner replenishing device 28. Also, it can be installed below the fixing device 40, and the influence of heat of the fixing device 40 can be prevented even during long-term use, and thermal deterioration of the toner can be suppressed.
Furthermore, the intermediate transfer belt 30 is disposed obliquely, the image forming unit 21 is provided below the image forming unit 21, and the distance from the image forming unit 21 to the secondary transfer position is shortened. It becomes possible to provide.

In this embodiment, when the upper unit 10a is opened, the fixing device 40 remains on the lower unit 10b side. For example, the upper fixing unit 40a of the fixing device 40 (see FIG. 3). Can be moved together with the upper unit 10a side. In this case, when a paper jam occurs in the fixing device 40, the jam processing can be easily performed as it is.
However, when the fixing device 40 is opened (divided into the upper fixing unit 40a and the lower fixing unit 40b), it is performed after the temperature of the heating roll 42 is cooled, or the user does not touch the heating roll directly. Such consideration is necessary.

Furthermore, in the present embodiment, the mode in which only one sheet tray 51 is mounted on the upper unit 10a is shown, but it is also possible to mount a plurality of sheet trays on the upper unit 10a. It becomes easier to replenish paper.
Further, a document reading device or the like may be further mounted on the upper unit 10a.

Embodiment 2
FIG. 6 is a schematic diagram showing Embodiment 2 of the image forming apparatus to which the basic configuration of the present invention is applied. The image forming apparatus 10 in the present embodiment is configured in substantially the same manner as in the first embodiment, but the moving direction of the upper unit 10a is different from that in the first embodiment. Note that the basic configuration of the image forming apparatus 10 is the same as that of the first embodiment, and a description thereof will be omitted.

The moving mechanism in the present embodiment is not an aspect in which the upper unit 10a of the image forming apparatus 10 has a rotation support shaft, and the upper unit 10a is a moving mechanism that moves substantially vertically upward when opened.
Even in this case, the gap between the resist roll 71 and the transport roll 74 is opened, and it becomes possible to easily perform jam processing when a paper jam occurs. Needless to say, the same effect as in the first embodiment can be obtained.
Further, in the present embodiment, for example, a rotation support shaft B for rotating the image forming engine 20 may be provided at the lower right of the image forming engine 20 of the lower unit 10b. The image forming engine 20 is rotated downward about the rotation support shaft B, the open space is further expanded, and it becomes easier to perform jam processing for paper jam.
Further, also in the present embodiment, the upper fixing unit 40a (see FIG. 3) of the fixing device 40 can be moved along with the movement of the upper unit 10a. In this case, the fixing device as in the first embodiment. Needless to say, consideration of 40 heat is necessary.

Embodiment 3
FIG. 7 is a schematic diagram showing Embodiment 3 of the image forming apparatus to which the present invention is applied. The image forming apparatus 10 in the present embodiment is configured in substantially the same manner as in the first embodiment, but on the lower unit 10b side, from the rotation support shaft A of the upper unit 10a to the approximate center line of the image forming apparatus 10. The difference from the first embodiment is that the rotation support shaft B of the image forming engine 20 is provided at a substantially opposite position.
Therefore, as shown in FIG. 8, as the upper unit 10a rotates upward with the rotation axis A as a fulcrum, the image forming engine 20 of the lower unit 10b moves downward with the rotation axis B as a fulcrum. Rotate to.
In the present embodiment, the upper unit 10a and the image forming engine 20 of the lower unit 10b move in opposite directions, so that a larger space can be secured, and jamming and maintenance for paper jam in the vicinity of the fixing device 40 can be secured. Is easier to perform.

  Further, in this embodiment, as shown in FIG. 8, the secondary transfer roll 35 is left on the lower unit 10b side, but this is because the image forming engine 20 side is separated from the secondary transfer roll 35. This is because it is not particularly necessary to move the secondary transfer roll 35 along with the upper unit 10a, but there is no problem even if the secondary transfer roll 35 is moved together with the upper unit 10a.

(A) and (b) are explanatory views showing the configuration of the image forming apparatus according to the present invention, where (a) shows a normal state, and (b) shows a state in which the recording material conveyance unit is opened for jam processing or the like. . 1 is an explanatory diagram showing a first embodiment of an image forming apparatus to which the basic configuration of the present invention is applied. FIG. FIG. 2 is an explanatory diagram illustrating a fixing device according to a first embodiment. FIG. 5 is an explanatory diagram showing the operation of the first embodiment. It is explanatory drawing which shows the image forming apparatus of the comparison form of this invention. FIG. 6 is an explanatory diagram illustrating an overview of an image forming apparatus according to a second embodiment. FIG. 10 is an explanatory diagram illustrating an overview of an image forming apparatus according to a third embodiment. FIG. 10 is an explanatory diagram showing the operation of the third embodiment. It is explanatory drawing which shows the image forming apparatus of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming engine, 2 ... Recording material conveyance system, 2a ... Recording material supply part, 2b ... Conveyance path, 2c ... Recording material discharge part, 3 ... Fixing device, 4 ... Upper movable unit, 5 ... Lower unit, 5a ... Lower movable unit, 6 ... Moving mechanism, 7 ... First moving mechanism, 8 ... Second moving mechanism, 9 ... Rotating spindle

Claims (4)

An image forming engine for forming a toner image and transferring the toner image to a recording material at a transfer site;
A recording material supply unit is provided above the image forming engine so that the recording material can be supplied, and the conveyance path of the recording material supplied from the recording material supply unit passes through a transfer portion with the image forming engine. A recording material conveyance system that is arranged so as to cross between the image forming engine and the recording material supply unit, and that accommodates and discharges the recording material in the recording material discharge unit through this conveyance path;
A fixing device that is provided between the image forming engine and the recording material supply unit and fixes the toner image transferred to the recording material at a transfer portion of the image forming engine;
A first moving mechanism for moving the upper movable unit including at least the recording material supply unit away from the opposing unit so as to be separable across the conveyance path of the recording material positioned before and after the fixing device;
A second moving mechanism for moving at least the lower movable unit including the image forming engine away from the opposing unit so that the recording material can be separated from the conveying path of the recording material positioned before and after the fixing device. ,
The first and second moving mechanisms have a rotation support shaft at a position opposite to each other across the vertical center line of the apparatus, and rotate in a direction to separate the upper movable unit and the lower movable unit together. an image forming apparatus comprising Rukoto allowed. The image forming apparatus according to claim 1.
The moving mechanism further moves a part of the fixing device with the movement of the upper movable unit. The image forming apparatus according to claim 1 , wherein
The image forming engine includes an image forming unit that forms and supports a toner image, and an intermediate transfer member that temporarily conveys and holds the toner image from the image forming unit, and the image forming unit is located below the intermediate transfer member. An image forming apparatus that is arranged. The image forming apparatus according to claim 3 .
The image forming apparatus, wherein the intermediate transfer member is a belt member.

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