JPH0213784B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus in which a process kit can be taken out from the main unit when the main unit is opened, but cannot be taken out when the main unit is closed.

Conventionally, in copying devices, etc., the upper and lower casings have been divided along the transfer paper feeding path in order to deal with malfunctions in transfer paper feeding and for maintenance and inspection of the device. There is. For example, a photosensitive drum,
The parts related to image formation, such as the optical system, developing section, and cleaning section, are attached to the upper housing, while the paper feeding section,
There is a device that is divided by attaching parts including a paper feeding system such as a transfer section, a transfer paper separation/conveyance section, and a fixing section to the lower casing. This division is configured to be openable and closable around a support shaft near the end of the main body. With this configuration, when a paper feeding failure occurs, it is possible to look around the path of the transfer paper, and furthermore, processing operations can be performed easily.

By the way, in the conventional device, as described above, the upper housing and the lower housing are constructed separately so that both can be opened and closed, and at the same time, a part of the wall of the upper housing can be opened and closed like a door. There is something. in this case,
You can take out a part of the image forming means individually with the door open, or you can integrate multiple image forming means and hold this integrated thing removably from the main body, or you can remove it from the main body. It has been proposed to configure the device so that it can be pulled out.

However, if the opening/closing operations of the upper and lower casings and the opening operations of the side wall doors can be operated independently, the side wall doors can be opened without opening the upper and lower casings. . As a result, in order to take out the image forming means, the image forming means to be taken out can be taken out by opening only the door on the wall without opening the upper and lower casings. This may cause damage to the main body or the image forming means that is being removed.

An object of the present invention is to provide an image forming apparatus that solves the above problems. Specifically, the purpose is to prevent the means provided on the process kit from being damaged by the main body apparatus or the main body apparatus from being damaged by these means when the process kit is taken out from the main body apparatus.

Hereinafter, the present invention will be explained in more detail using an electrophotographic copying apparatus as an example.

FIGS. 1 and 2 are explanatory diagrams of the configuration of an embodiment of an electrophotographic copying apparatus to which the present invention is applied. Note that FIG. 2 is a diagram showing the copying machine shown in FIG. 1 in an open state. In FIG. 1, reference numeral 1 denotes a document mounting table made of a transparent member, which reciprocates in the direction of the arrow. Reference numeral 2 denotes an imaging element array which slit-exposes the optical image of the original image on the original table 1 onto the OPC photosensitive drum 3 serving as an image carrier. Note that the photosensitive drum 3 rotates in the direction of the arrow. 4 is a corona charger that uniformly charges the photosensitive drum. A developing device 5 develops an electrostatic latent image formed by exposing a uniformly charged photosensitive drum to light using the array 2 with toner.

On the other hand, the transfer sheet P is fed onto the surface of the drum 3 by a feeding roller 6 and a register roller 7, and the toner image on the drum is transferred by a transfer charger 8. Thereafter, the sheet is separated from the drum by the separating means 13, passed over the guide 9, and sent to the fixing device 10 by the roller 9a located at the end of the conveyance path. The toner image on the sheet is fixed by the fixing device 10, and the sheet is transferred to the tray 1 by the ejection roller 11.
2 is discharged on top. On the other hand, toner remaining on the photosensitive drum 3 without being transferred is collected by a cleaning device 14. Furthermore, 15 is an illumination system for exposing the mounting table, and 16 is a filter such as a heat ray absorption filter.

Now, as shown in FIG. 2, this copying machine is divided into an upper housing 17 and a lower housing 18, which are connected by a support shaft 19 in a separable manner, and the upper housing 17 rotates upward around this support shaft 19. It is configured to move. This upper housing 17 includes an illumination optical system 2, 15, a photosensitive drum 3,
Image forming means such as a developing means 5 and a cleaning device 14 are arranged. In addition, the lower housing 18 includes
A feeding roller 6, a transfer charger 8, a separation means 13, a guide 9, a fixing device 10, and the like are arranged on the sheet conveyance path.

Furthermore, in this embodiment, the image forming means such as the developing device 5, the cleaning device 14, the charging device 4, etc. arranged around the photosensitive drum 3 are integrated and wrapped with a light-shielding wall to constitute the process kit 30. At the time of replacement, each unit in the kit 30 is replaced at the same time, thereby reducing maintenance work. The process kit is attached to and detached from the main unit by moving the kit 30 along the rails 29a and 29b on the copying machine main body side in the direction of the rotation axis of the drum 3. The case where this kit 30 is taken out from the main body will be described below.

20 located at the bottom of the kit is made of an opaque, e.g.
A cover that shields and protects the exposed surface of the drum 3 made of ABS resin, and an example of its configuration is shown in FIG. 21b
The end portions of the drum cover 20 are rotatably fitted to both longitudinal ends of the drum cover 20 via a shaft 27.
Further, both longitudinal ends of the other end of the drum cover 20 are connected to swing arms 22a, 22b and a shaft 2.
8 and are rotatably engaged. Further, the swing arms 22a, 22b are fixed to a shaft 23, and an actuation lever 25 is further fixed to an end of the shaft 23. As shown in the figure, the swinging arms 21a and 21b are given the habit of rotating counterclockwise by a spring 24. Note that 30d in the figure shows a part of the inner cover of the kit 30.

In the above configuration, when the operating lever 25 is moved clockwise by a mechanism described later, the shaft 23 rotates clockwise, and the cover 20 is moved clockwise by the swinging arms 22a and 22b, one end of which is fixed to this shaft. The photosensitive drum 3 can be rotated and retracted from the circumferential surface of the photosensitive drum 3.

That is, in this embodiment, as shown in FIG. 4, a protrusion 26 is integrally fixed to the lower housing 18, and when the kit 30 is loaded in a predetermined position, the protrusion 26 is attached to the upper housing 17. When the spring 24 is closed, both ends of the spring 24 are locked by the protrusion 24a on the inner cover 30d and the protrusion 24b on the arm 21a, so the operating lever 25 is rotated clockwise and the cover 20 is automatically closed. It is possible to form an image by retracting from the circumferential surface of the drum and exposing the photosensitive drum.

Conversely, when the upper housing 17 is opened upward, as shown in FIG. , 21b rotates counterclockwise, and in conjunction with this, the drum cover 20
rotates counterclockwise to reach the vicinity of the circumferential surface of the drum 3, and covers the exposed portion of the photosensitive drum 3 from the wall portion 30a. That is, when the housing 17 is opened, the cover 2
0 automatically covers the exposed portion of the circumferential surface of the drum 3 and blocks light, thereby preventing the influence of light on the circumferential surface of the drum 3 and at the same time preventing scratches.

In the above description, a case has been exemplified in which the surface of the photoreceptor exposed from the process kit is shielded from light by opening and closing a part of the main unit. The opening and closing of the main body is performed for maintenance and inspection of the apparatus and for handling defective conveyance of the transfer sheet, and even in such cases, it is possible to protect the photoreceptor surface from being exposed to light.

In the configuration of the above embodiment, when attempting to attach or detach the process kit to the main unit, the second
The main body case is divided into upper and lower parts as shown in the figure, the door provided on the wall of the upper case is opened by a mechanism described later, and the process kit 30 is opened along the rails 29a and 29b.
is moved in the axial direction of the photosensitive drum. At this time,
Due to the structure of the drum cover described above, the exposed portion of the transfer portion of the drum 3 is shielded from light.

In the apparatus of this embodiment, the process kit 30 is taken out from the upper housing by opening the front door 31 provided in the upper housing as shown in FIG. The front door 31 has a configuration that cannot be opened unless the upper housing is opened to the lower housing. That is, by opening the upper housing, a sufficient distance can be maintained between the lower housing 18 and the process kit 30 to be attached to and removed from the main body, and at the same time, the photosensitive drum 3 of the kit can be
The kit can be removed after the protective cover 20 has automatically covered it.

FIG. 6 is a front view of the device for explaining the mechanism for opening and closing the front door of the present invention, and FIGS. 7 to 11 are cross-sectional views of the device shown in FIG. 6 when viewed from arrow A.
The front door opening and locking mechanism is shown.

In the figure, the front door 31 has a hinge portion 32 connected to a hinge portion 33 on the upper housing 17 side of the main body via a pin 35, and both hinges can be opened by swinging around the pin 35. There is. On the inside of the front door 31, a lever 36 is held by dowels 37, 38 fixedly installed on the front door 31 through elongated holes, so that it can be moved up and down. Therefore, when the upper housing is closed, the lower end 36 of the lever 36
a is in contact with the edge 18a of the lower housing. On the other hand, a stopper 39 is provided at a position corresponding to the tip 36b of the lever 36 so as to be swingable about a pin 40 fixed to the upper housing 17 side.
One end 39a of the stopper 39 abuts against the edge 41 on the upper housing to maintain the state shown in FIG. 7.
Here, when the upper housing 17 is closed as shown in FIG. 7, the height of the tip 36b of the lever 36 is higher than the other end 39b of the stopper 39 (L ₁ in the figure), and the height of the other end 39b is It is higher than the height of the pin 40, which is the center of rotation of the stopper 39 (L ₂ in the figure). At this time, the distance L ₁ is smaller than the amount L ₃ of the lever 36 that can be swung by the elongated hole.

The operation of the front door 31 will be described in detail below.

As shown in FIG. 7, when a force is applied to open the front door 31 when the upper housing 17 is in the closed state, the tip 36b of the lever 36 comes into contact with a part of the other end 39b of the stopper 39. The stopper 39 receives a counterclockwise moment about the pin 39. However, one end 39a of the stopper 39
As a result, the front door 31 cannot be opened because the lever 36 cannot release the engagement with the stopper 39.

The following FIG. 8 is a sectional view when the upper housing 17 is opened to the lower housing 18. When the upper housing 17 is opened as shown in the figure, the lower end 36a of the lever 36
is released from contact with the edge 18a of the lower housing 18, and the lever 36 moves downward within the opening range of the elongated hole. As a result, the upper end 36b of the lever 36 is
It is located below the position of the other end 39a of the stopper 39, and is rotatable about the shaft 35. the result,
As shown in FIG. 9, the front door 31 can be opened, and the process unit 30 can be mounted on the rails 29a and 29 of FIG.
It becomes possible to pull it out along b.

After replacing the process unit 30,
When the front door 31 is closed, the state shown in FIG. 8 is restored. When the upper casing 17 is further closed with respect to the lower casing, the state is returned to that shown in FIG. 7, and the copying operation is again possible.

Here, if you forget to close the front door 31 to a predetermined position and close the upper housing 17 to the lower housing 18 as shown in FIG. 10, as shown in FIG.
The front door 31 is in a half-open state with respect to the housing. However, when the front door 31 is pushed in the direction of arrow A to close it, the lower end 36a of the lever 36 is in contact with the edge 18a of the lower housing 18, so the tip 36b of the lever 36 moves the stopper 39 to the center of the pin 40. Rotate clockwise as shown. As a result, as shown in FIG.
b (FIG. 11), and then the stopper 3a rotates under its own weight until the other end 39b abuts against the edge 41 of the upper casing, returning to the state shown in FIG. 7 again. Once you reach the state shown in Figure 7,
With the above configuration, the front door 31 cannot be opened unless the upper housing 17 is opened again.

As in the above embodiment, a part of the wall of the upper case is used as a front door, and this door is equipped with a locking mechanism that is released from the upper case only when the upper case is opened to the following cases. Established. This makes it possible to take out the transfer paper from the door in a state where the passage of the transfer paper is open, that is, in a state where the internal image forming means such as the process kit is sufficiently separated from the passage of the transfer paper. Furthermore, when the upper and lower casings are not opened, the front door is locked and cannot be opened, preventing damage to the main body or the image forming means due to the inability to take out the latent image forming means. In addition, even if the photoconductor drum contains a photoconductor that is adversely affected by external light (for example, the generation of optical memory), the photoconductor may become unusable if the front door is opened inadvertently. It can also be prevented. The present invention is applicable not only to copying machines but also to other recording devices.

As mentioned above, if the device has a mechanism that automatically covers the exposed part of the photosensitive drum at the same time as the upper housing is opened, the front door will not open if the exposed part is not covered by the above configuration. Since it cannot be opened,
It becomes possible to prevent the harmful effects of light as much as possible.

In the embodiments described above, the outlet for the image forming means that is detachable from the main body is provided in front of the upper casing, but a similar door may be provided in other wall portions. As for the form of the image forming means within the main body, as described above, it is made into a kit and can be integrally attached to and removed from the main body. Of course, each member disposed in the upper casing and each member disposed in the lower casing are not limited to those in the embodiment. At the same time, the image forming means that is removably attached to the main body may be a single photoreceptor, a developing device, or a cleaning device. Furthermore, as another form of the locking means, the position of the above-mentioned casing may be detected by a detection means such as a micro switch, and based on this detection signal, driving means such as a plunger may be driven to lock the lever. good.

According to the present embodiment described above, unless the upper housing is opened, it is possible not to form an opening for taking out the image forming means inside. This prevents the casing from being opened carelessly, thereby preventing accidents caused by attachment and detachment of the image forming means inside, or from adversely affecting the photoreceptor due to light when there is a photoreceptor inside.

As described in detail above, the present invention provides an image forming apparatus from which a process kit cannot be taken out carelessly from the main unit.

[Brief explanation of drawings]

1 and 2 are sectional views of essential parts of an electrophotographic copying apparatus to which the present invention is applied, FIG. 3 is a perspective view showing the opening and closing operation of the protective plate of the photosensitive drum of the process kit, and FIGS. 4 and 5. 6 is a front view of the front door showing an embodiment of the present invention, and FIGS. 7 to 11 show the opening and closing operations of the upper and lower casings. FIG. 3 is a sectional view of the device showing the front door locking mechanism according to the present invention. In the figure, 17 is an upper housing, 18 is a lower housing, 31 is a front door, 36 is a lever provided on the front door constituting the locking means, and 39 is a stopper provided on the upper body constituting the locking means.

Claims (1)

[Scope of Claims] 1. An image forming apparatus whose main body is separable into a first housing and a second housing with a sheet conveyance path as a boundary; a unit that is removable from the image forming apparatus; In order to attach and detach from the forming device, an opening/closing means is provided on the casing on the side where the unit is attached, and when the first and second casings are closed, the opening/closing means is prevented from opening. , prevents the unit from being attached or detached,
An image forming apparatus comprising: means for allowing the opening/closing means to be opened when the first and second casings are opened. 2. The unit includes: an image carrier, a working means disposed around the image carrying member and acting on the image carrying member, and a supporting means that integrally supports the image carrying member and the working means. The image forming apparatus according to claim 1, which is a process kit comprising: