JPH0510665B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus that forms an image on a recording medium, and a process kit that is detachable from the main body of the image forming apparatus.

The photoconductive layer is charged around a photoreceptor, which is an image carrier, and is exposed to light corresponding to an image to form an electrostatic latent image. Next, a normal powdered developer (toner) is applied to this to form a transferable image, a transfer material is brought close to the image, the image is transferred to the transfer material, the photoreceptor is cooled, and the above-mentioned steps are carried out. Repetitive image forming apparatuses have been widely put into practical use. In this type of image forming apparatus, there has been a process kit in which the photoreceptor and all or part of the peripheral members for carrying out the above-mentioned processes are integrally arranged inside a casing. Used in image forming devices.

In an apparatus equipped with such a process kit, an optical system unit for forming an electrostatic latent image on a photoreceptor is generally disposed above the image forming apparatus, and a charging means for charging the photoreceptor and a charging means for forming an electrostatic latent image on the photoreceptor are provided. It is common to have a structure in which developing means for revealing, cleaning means, etc. are arranged close to the photoreceptor. Therefore, a well-known process kit is one in which the charging, developing, and cleaning means described above are integrally housed in a casing.

In such image forming apparatuses that have a scanning optical system that uses a laser as the light source for exposure, when removing the process kit from the apparatus main body, it is necessary to open the main body cover in order to remove it. Therefore, it was common for the laser to stop emitting light by opening a microswitch. However, due to a malfunction or failure of the switch, laser light is emitted even when the process kit is removed from the apparatus main body, and there is a risk that the laser light may leak out of the apparatus.

For example, JP-A-51-90826, JP-A-51-
As described in Japanese Patent Application Laid-open No. 90830 and Japanese Patent Application Laid-Open No. 164845/1983, a configuration is known in which the opening and closing of the shutter is controlled by electrical control. However, with such a configuration, if an electrical failure occurs, there is a risk that the shutter will not be able to be opened or closed.

The present invention has been developed in view of the above situation, and is designed to prevent the process kit from attaching or detaching parts that may cause laser light leakage, or a series of related operations, such as when taking out a process kit from the apparatus main body. It is possible to block the optical path of the laser beam and reliably prevent the laser beam from leaking to the outside.Also, when the process kit is installed, image formation cannot be performed if the optical path of the laser beam is blocked. An object of the present invention is to provide an image forming apparatus and a process kit that are automatically opened.

To achieve the above object, the present invention provides a process kit that is detachable and includes an image carrier and a process unit that acts on the image carrier, and includes a laser light irradiation unit that irradiates the image carrier with laser light. an image forming apparatus that forms an image on a recording medium, the shutter being movable between a blocking position where the laser beam from the laser beam irradiation means is blocked and an open position where the laser beam is evacuated from the blocking position; The image forming apparatus is characterized in that it has a moving means for moving the shutter from the open position to the shut-off position in response to an operation of taking out the process kit from the image forming apparatus. Still further, another aspect of the present invention provides a process kit including an image carrier and a process unit that acts on the image carrier, which is removable, and a laser light irradiation unit that irradiates the image carrier with laser light. an image forming apparatus that forms an image on a recording medium, the shutter being movable between a blocking position where the laser beam from the laser beam irradiation means is blocked and an open position where the laser beam is evacuated from the blocking position; The image forming apparatus further comprises a moving means for moving the shutter from the shut-off position to the open position in accordance with the mounting operation of the process kit on the image forming apparatus main body. Still another aspect of the present invention provides a process kit that is removably attached to an image forming apparatus main body that forms an image on a recording medium by having a laser beam irradiation means that irradiates the image bearing member with a laser beam. process means acting on the image carrier;
In response to the mounting operation of the process kit on the image forming apparatus main body, acting on an opening means for opening a shutter provided on the image forming apparatus main body that blocks laser light from the laser light irradiation means,
The process kit includes an opening member for opening the shutter.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The embodiment described below is an image forming apparatus that includes a laser scanning optical system, an image carrier, and means for forming an image on the image carrier, and the scanning optical system is operated in conjunction with the movement of a movable member. This is an image forming apparatus configured to block laser light from the system. The image carrier and part or all of the image forming means for forming an image on the image carrier are integrally constructed. Furthermore, the image forming apparatus shuts off the laser light of the scanning optical system when the image carrier, the image forming means, or a member that integrates these is attached or detached. Still further, the image forming apparatus is such that the image carrier, the image forming means, or a member that integrates these can be attached and detached only when the laser beam of the scanning optical system is cut off.

Now, FIG. 1 shows a laser printer to which the present invention is applied. In the figure, a scanning optical system unit 1 including a scanner motor, a polygon mirror, a mirror, etc. is disposed above a main body 100, and this unit is attached to a substrate 2 inside the main body. A rotating cylindrical photoreceptor 3 is arranged below the substrate 2, and around it a charger 4, a developer 5,
Processing means that act on the photoreceptor 3, such as a transfer charger 6 and a cooling device 7, are arranged, and these processing means are housed together with the photoreceptor 3 in a casing 8 to form a process kit 10. Image exposure according to information is applied to the surface of the photoreceptor uniformly charged by the charger 4 through the aperture 1a of the unit, the aperture 2a of the substrate 2, and the aperture 8a of the casing 8. is performed to form an electrostatic latent image. Next, this latent image is visualized by the developing device 5, and the arrow A in the figure
The image is transferred onto the transfer material fed in the direction at the transfer site where the transfer charger 6 is present. The transfer material carries this toner image and advances to the left in the figure until it reaches the fixing device 9.
It is fixed and fixed at the position and is ejected from the main body. It is assumed that the toner that does not contribute to the transfer at the transfer site is removed from the photoreceptor by the cooling device 7, and then the image forming process similar to that described above is repeated.

In the embodiment shown in the first figure, a shutter 11 for opening and closing the opening 2a is provided on the lower surface of the substrate 2, and a process kit 10 is provided.
In response to this, when the kit 10 is attached and removed from the main body 100, the shutter 11 closes to the opening 2.
A is opened and the kit 10 is removed from the main body, and the shutter 11 closes the opening 2a.

FIG. 2 is a perspective view of essential parts showing the structure of the shutter and related operations of the process kit 10. A long shutter plate 11 for opening and closing the scanning opening 2a is arranged on the lower surface of the substrate 2 so as to be slidable along the lower surface. In the illustrated example, long holes 11 are provided near both sides of the shutter plate 11.
pins 2b and 2c fixed to the substrate 2 are loosely fitted into these elongated holes to support the shutter plate 11 on the lower surface of the substrate 2 and to enable it to slide. Shutter board 1
Appropriate means can be used, such as engaging both side edges of the substrate 1 with guide paths formed on the lower surface of the substrate 2. The other ends of springs 12a and 12b are fixed to the shutter plate 11, one end of which is attached to the base plate 2 and other immovable parts.
As shown in FIG. 2, it has a habit of closing the opening 2a. Furthermore, the shutter board 11
Legs 11a and 11b are extended at both ends of the kit 10, and the leg 1 on the back side is
1a is formed longer than the leg portion 11b on the near side.

The process kit 10, which is loaded and unloaded from the lower part of the substrate 2 in the main body, is operated at a position such that the long hole 8a for optical scanning formed on the top surface of the process kit 10 matches the long hole 2a of the shutter plate 11. Two protrusions 13 and 14 are formed on the top of the casing of the kit, and on one side of each of these protrusions are legs 11a and 11b of the shutter plate, respectively.
Tapered portions 13a and 14a are formed to engage with.

When the process kit 10 is moved in the direction of arrow B in FIG.
14a are the legs 11a, 1 of the shutter plate 11, respectively.
1b, the shutter plate 11 is displaced in the direction of arrow C in the figure against the action of the springs 12a and 12b, opening the opening 2a of the base plate 2, and the kit 10 is brought to the fixed position in the main body. Opening 2a where
The aperture 1a of the scanning optical system unit 1 and the aperture 8a of the kit coincide with each other, and the exposure is possible.

When the kit 10 is pulled out in the direction reflected by the arrow B in FIG.
The shutter plate 11 closes the opening 2a of the substrate by displacing the shutter plate 11 in the direction opposite to the arrow C in the figure while contacting the tapered portions 13a and 14a of the substrate 4.
It is possible to reliably prevent laser light from accidentally leaking to the outside.

In addition, as mentioned above, both legs 11 of the shutter plate
a and 11b have different lengths, and correspondingly, the protrusions 13 and 14 on the kit side are also at different positions when viewed in the direction of displacement of the shutter plate, so when installing and removing the kit, For example, the leg portion 11b does not interfere with the entry of the protrusion 13.

FIG. 3 shows another embodiment of the invention.

In this embodiment, pins 11c and 11d are provided on one side edge of the shutter plate 11 disposed on the lower surface of the opening 2a formed in the substrate plate 2, and the shutter plate 11 is rotated around these pins. In addition to being freely attached, springs 12a and 12b are arranged on the other side edge so that the shutter plate 11 always closes the opening 2a.

A downwardly extending engaging portion 11e is provided at one edge of the shutter plate 11, and this engaging portion responds to attachment and detachment of the process kit 10 to and from the image forming apparatus as will be described below.

The process kit 10 has a groove 8c extending parallel to the opening 8a that matches the opening 2a when the process kit 10 is installed in the image forming apparatus, and one side 8d of the groove 8c is open as shown in the figure. The side end e is almost vertical (assuming that the kit 10 is moved horizontally back and forth to be attached to and removed from the image forming apparatus), and the other end f is nearly horizontal. , f is formed into a twisted surface whose angle changes smoothly. Further, when the process kit 10 is moved and attached to the image forming apparatus in the direction of arrow B, the engaging portion 11e of the shutter plate 11 is attached to the kit 10 at the initial position of the attachment.
It is assumed that each part is arranged in relation to each other so as to lightly abut the end e of the side surface 8d. Therefore, when the kit 10 is pushed in from the position where the engaging portion 11e and the end e of the side surface 8d face each other as described above, the engaging portion 11e will move along the side surface 8d and the pin 1
The kit 10 rotates about 1c and 11d against the action of the springs 12a and 12b, and when the kit 10 reaches the internal position of the device, the engaging portion 11e reaches the other end f of the side surface 8d. The shutter plate 11 is rotated to open the opening 2a of the board 2. When the process kit 10 is pulled out from the device,
Along with this, the engaging portion 11e of the shutter plate 11
is rotated along the side surface 8d on the side of the kit 10 in the opposite direction to that described above, and the kit 10 is removed, and the substrate 2a is closed by the shutter plate 11 to prevent leakage of the laser beam. The kit 10 is provided with a recess 8e in the vicinity of the opening 8a on its top surface to allow the shutter plate 11 to rotate. Since this device is configured to rotate the shutter, it is possible to open and close the shutter in a relatively small space.

Regarding the embodiments shown in FIGS. 2 and 3 above,
Although the attachment/detachment of the process kit and the opening/closing of the shutter are shown as being linked, it is of course possible that they do not need to be linked.

Although not directly related to the present invention, FIG. 4 shows another embodiment related to attaching/detaching the process kit and opening/closing the shutter. This figure is a perspective view of a main part showing a process kit located at a fixed position below a substrate 2 of an image forming apparatus. Pivot support 11a, 11b is provided at both ends of the unit on the side walls of the unit. A falling piece 11c is integrally formed at the end of the shutter plate 11 on the side where the process kit 10 is attached/detached, and as shown in the figure, when the process kit 10 is in the normal position, the shutter plate 11 is , as shown by the solid line, is positioned so as to overlap the surface of the substrate 2, so that there is no problem in exposing the photoreceptor. At this time, since the falling piece 11c is engaged with the end surface of the kit 10 on the drawer side, the kit 10 cannot be pulled out. When taking out the kit 10, the falling piece 11c must be rotated in the direction of arrow C in the figure to disengage the end face of the kit 10. When the falling piece C is rotated in this manner, the shutter plate 11 is also rotated as shown by the chain line in the figure, thereby blocking the laser beam. Therefore, when taking out the process kit 10 in this state, the laser beam is reliably shielded by the shutter plate and there is no risk of leakage. Further, in this embodiment, since the shutter plate 11 is disposed inside the optical unit, the entire apparatus can be made compact.

As explained above, the image forming apparatus described above is configured so that the optical path of the laser beam can be interrupted when the members constituting the apparatus are attached to and detached from the apparatus. Even if a failure occurs, it is possible to reliably prevent the laser beam from leaking out of the device.

As detailed above, according to the present invention, the reliability of preventing laser light from leaking to the outside of the device is improved, and the shutter is automatically opened in response to the mounting operation of the process kit to improve the reliability. It is possible to provide an image forming apparatus that can perform image formation and a process kit that is detachable from the image forming apparatus.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view schematically showing the configuration of an image forming apparatus to which the present invention is applied, FIGS. 2 and 3 are perspective views of essential parts each showing an embodiment of the present invention, and FIG. 4 is a diagram of a process kit. This is an embodiment related to attachment/detachment and opening/closing of the shutter. 1...Scanning optical system unit, 2...Substrate, 3...
...Photoreceptor, 5...Developer, 7...Cleaning device, 8...Casing, 10...Process kit, 11...Shutter plate.

Claims (1)

[Scope of Claims] 1. A process kit including an image carrier and a process unit that acts on the image carrier is removable, and includes a laser light irradiation unit that irradiates the image carrier with laser light. In an image forming apparatus that forms an image on a recording medium, the shutter is movable between a blocking position where the laser beam from the laser beam irradiation means is blocked and an open position where the shutter is evacuated from the blocking position; a moving means for moving the shutter from the open position to the shut-off position in response to an operation of removing the process kit from the image forming apparatus main body;
An image forming apparatus comprising: 2. The image forming apparatus according to claim 1, wherein the process means includes a charging means for charging the photoreceptor as the image carrier. 3. The image forming apparatus according to claim 1, wherein the process means includes a developing means for making a latent image visible. 4. The image forming apparatus according to claim 1, wherein the process means includes a cooling means for cleaning the photoreceptor as the image carrier. 5. A process kit including an image carrier and a process unit that acts on the image carrier is removable, and includes a laser beam irradiation unit that irradiates the image carrier with a laser beam, and the process kit includes an image carrier and a process unit that acts on the image carrier, An image forming apparatus for forming a process kit, comprising: a shutter movable between a blocking position for blocking laser light from the laser beam irradiation means and an open position for retracting from the blocking position; and an image forming apparatus for the process kit. An image forming apparatus comprising: a moving means for moving the shutter from the blocking position to the opening position in response to an operation of attaching the shutter to a main body. 6. The image forming apparatus according to claim 5, wherein the process means includes a charging means for charging the photoreceptor as the image carrier. 7. The image forming apparatus according to claim 5, wherein the process means includes a developing means for making a latent image visible. 8. The image forming apparatus according to claim 5, wherein the process means includes a cooling means for cleaning the photoreceptor as the image carrier. 9. A process kit detachably attached to an image forming apparatus main body that has a laser beam irradiation means for irradiating an image carrier with a laser beam and forms an image on a recording medium, comprising: an image carrier; and a process that acts on the image carrier. and acting on an opening means for opening a shutter provided on the image forming apparatus main body that blocks the laser light from the laser light irradiation means in accordance with the mounting operation of the process kit on the image forming apparatus main body, A process kit comprising: an opening member for opening the shutter. 10. The process kit according to claim 9, wherein the process means includes a charging means for charging the photoreceptor as the image carrier. 11. The process kit according to claim 9, wherein the process means includes a developing means for making a latent image visible. 12. The process kit according to claim 9, wherein the process means includes a cooling means for cleaning the photoreceptor as the image carrier.