JPH0310513Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to image forming apparatuses such as copying machines and printers, and in particular divides the recording paper conveyance path into two units, and each unit is removably attached to the main body of the image forming apparatus. This relates to an image forming apparatus.

Conventionally, in order to facilitate operations such as inspecting an image forming apparatus, replacing a photoreceptor, or removing jammed recording paper, an image forming apparatus has been constructed in such a way that a part of the main body of the apparatus is made into a unit that can be pulled out. There is a device. However, in general, in this type of image forming apparatus, the unit is pulled out parallel to the support shaft of the photoreceptor drum, that is, perpendicular to the conveyance direction of the recording paper, so that jammed recording paper tends to get stuck on the photoreceptor drum, etc. However, it was difficult to remove the recording paper, and there was also a risk of damaging the photosensitive drum.

Furthermore, the photoreceptor drum of conventional image forming apparatuses is
It is removably mounted in a direction parallel to the rotation axis, and when moving the photoconductor drum in a direction parallel to the rotation axis, a through hole with a slightly larger diameter than the photoconductor drum is made in the front wall of the main body of the device. It is enough to set it up. Therefore, there is no need to provide a special passage to take out the photosensitive drum, and the entire apparatus can be made compact. However, in this case, there are the following problems. That is, first, a through hole with a diameter larger than that of the photoreceptor drum must be formed in the front wall of the frame that constitutes the main body of the apparatus. If such a through hole is provided in the front wall of the frame, the frame will be weakened and additional reinforcing members will be required, which will increase the number of component parts, increase costs, and increase the overall weight.
Furthermore, when attaching or detaching the photoconductor drum, there is a high risk that the photoconductor surface may come into sliding contact with other mechanical parts within the device.
The important photosensitive surface was often scratched.

The present invention was made in view of the drawbacks of the conventional example, and includes a photoreceptor drum, an optical system for forming an electrostatic latent image on the photoreceptor drum, and a developing device for developing the electrostatic latent image with toner. , an electrophotographic copying machine equipped with a device for transferring a toner image onto a copy paper, a cleaning device for cleaning toner remaining on a photoreceptor, and a paper feeding device for feeding the copy paper to a transfer position, the developing device is removably installed from above the copying machine main body, and the space formed after the developing device is removed has dimensions that allow the photosensitive drum to pass through, and the paper feed device is pulled out horizontally relative to the copying machine main body. It is an object of the present invention to provide an image forming apparatus in which the space formed after the developing device is freely installed and the paper feeding device is pulled out has a size that allows the photosensitive drum to pass through. .

Hereinafter, one embodiment of the present invention will be described based on the drawings. Reference numeral 1 denotes a copying machine main body, on the upper surface of which a document table 2 is placed so as to be slidable in the left and right direction. Further, a document table cover 3 is attached to the upper part of the document table 2 so as to be openable and closable. Reference numeral 4 denotes a photosensitive drum supported by a support shaft 5 approximately at the center of the main body 1 of the copying machine. Around the photosensitive drum 4, there is an exposure optical system 6 that forms an electrostatic latent image on the photosensitive surface, a developing device 7 that develops the electrostatic latent image with toner, a transfer corotron 9 that transfers the toner image onto copy paper 8, and a cleaning device 1 for cleaning residual toner on the photoreceptor drum 4
0 are sequentially arranged clockwise in the figure. The exposure optical system 6 is composed of a lamp 11 that exposes the document surface, and a short focus lens array 12 that forms an image of the document onto a photosensitive surface.Upstream of this short focus lens array 12,
A charging corotron 13 for charging the photosensitive surface is fixedly installed. The cleaning device 10 also includes a static eliminating corotron 14 that removes residual potential on the photosensitive surface, and a blade 15 that scrapes off residual toner.
The residual toner scraped off by this blade 15 is transferred to a residual toner storage box 17 by a transfer roller 16. Note that on the downstream side of the transfer corotron 9, a separation corotron 18 for separating the copy paper 8 from the photoreceptor drum 4 is arranged adjacently.

Reference numeral 19 denotes a paper feed cassette in which transfer paper 8 is loaded and stored, and a paper feed roller 20 is pressed against the upper part of the paper feed cassette 19 for intermittently feeding the uppermost copy paper 8 in the paper feed cassette 19. . 21, 21 is paper feed cassette 1
A registration roller provided on the downstream side of the copy paper 9 temporarily stops the copy paper 8 fed by the paper feed roller 20 and feeds it again to the transfer position at the appropriate timing. In addition, this register roller 2
Paper feed guides 22 and 22 are provided between the paper feed rollers 1 and 21 and the paper feed roller 20. Reference numeral 23 denotes a vacuum conveyor provided on the downstream side of the separation corotron 18, which transports the copy paper 8 after transfer to a fixing section. The components from the paper feed cassette 19 to the vacuum conveyor 23 are integrated and are provided so as to be able to be pulled out to the right from the main body 1 of the copying machine. 2
4 is a power connector.

A fixing device 25 includes a heating roller 27 with a built-in heater 26, and a pressing roller 2 that presses the copy paper 8 with toner transferred to the heating roller 27.
8, and paper ejection rollers 29, 29 that eject the copy paper 8 on which the toner has been fixed. 30 is a switch for checking the paper discharge state. Note that this fixing device 25 is also integrated and provided so as to be able to be pulled out to the left in the figure.

Reference numerals 31 and 31 designate drum guides fixed to the front and rear walls of the frame constituting the main body 1 of the copying machine, respectively, in which guide grooves 32 and 32 are formed that bend horizontally and vertically upward. This guide groove 32,
The width of the flange 32 is slightly wider than the outer diameter of the flanges 33 formed protrudingly from both end surfaces of the photoreceptor drum 4 . Reference numeral 34 denotes a stopper fixed to the front rear wall for positioning the developing device 7.
The developing device 7 is mounted vertically upward so that it can be freely pulled out.

In this embodiment, in order to take out the photosensitive drum 4, first move the document table 2 to the left, then pull out the developing device 7 upward, and then remove the unit from the paper feed cassette 19 to the vacuum conveyor 23. Pull it out to the right. Thereafter, the support shaft 5 of the photoreceptor drum 4 is pulled out in a direction parallel to the axis thereof, and the photoreceptor drum 4 is inserted into the drum guide 31,
31 and take it out. At this time, the flange 33 of the photosensitive drum 4 moves while slidingly contacting the guide grooves 32, 32. Although the above description has been made using an electrophotographic copying machine as an example, the present invention can also be applied to various other image forming apparatuses (eg, LED printers, etc.).

As mentioned above, according to the present invention, the recording paper conveyance path from the paper feed end to the paper ejection end is divided into two units, and each unit is constructed so that it can be pulled out from the main body. Since either one of each unit or both units can be pulled out at the same time if necessary, even if a paper jam occurs in any part of the recording paper conveyance path, there is no need to reach into the main body, and the jam can be easily cleared. In addition, the risk of the operator's hand touching the photosensitive drum or the risk of damaging the photosensitive drum is completely eliminated. Since the transport path is divided into two units that can be pulled out in directions away from each other, the unit and main body do not need to be as strong and the weight can be reduced compared to when the entire transport path is pulled out as one unit. It can be reduced. Therefore, when pulling out each unit, jams can be easily removed without requiring much force. Furthermore,
Even when each unit is pulled out, the center of gravity of the device body does not move much, resulting in excellent stability.
One of the two units includes a recording paper transport path from the paper feed section to the fixing device, and the other includes the fixing device and paper ejection section. If a blockage occurs, it is only necessary to pull out that unit out of the two, so not only does the operator not have to worry about the heat generated by the fixing device, but also the fixing device and the transport path leading to it. is divided, so
The heat generated by the fixing device is transferred to other parts,
Other parts are hardly affected by heat. The photosensitive drum can be taken out through the space created by taking out the developing device and pulling out the unit that includes the recording paper conveyance path from the paper feeding end to the front of the fixing device.
There is no need to provide a special passage, and the apparatus can be made compact, and there is no risk of scratching the photosensitive surface when taking out the photosensitive drum. Since it is not necessary to pull out the photosensitive drum in its axial direction and there is no need to provide a through hole in the frame, the frame does not become weakened and costs can be reduced.

[Brief explanation of drawings]

Each of the drawings shows an embodiment of the present invention.
2 is a front sectional view showing a state in which each component is installed, FIG. 2 is a front sectional view showing a state in which the developing device and paper feed device are removed, and FIG. 3 is a perspective view showing the main parts. 1... Copying machine main body, 4... Photosensitive drum, 6...
...Optical system, 7...Developing device, 8...Copy paper, 9...
...Transfer corotron, 10...Cleaning device,
19...Paper feed cassette, 20...Paper feed roller, 2
1, 21...Register roller.

Claims (1)

[Scope of Claim for Utility Model Registration] A photoconductor drum, an optical system that forms an electrostatic latent image on the photoconductor drum, a developing device that develops the electrostatic latent image with toner, and transfers the toner image onto recording paper. In an image forming apparatus equipped with a cleaning device for cleaning toner remaining on a photoreceptor, and a paper feeding device for feeding recording paper to a transfer position, the developing device is detachable from above the main body of the image forming apparatus. The paper feeding device is attached to the main body of the image forming apparatus so as to be freely pulled out in a horizontal direction, and the photosensitive drum is inserted through the space formed after taking out the developing device and pulling out the paper feeding device An image forming apparatus characterized in that the image forming apparatus can be taken out from above the image forming apparatus main body.