JPH0442847Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an image forming apparatus such as a laser beam printer.

(Prior Art) Conventionally, there is a laser beam printer that combines an electrophotographic method and a laser scanner and is configured as shown in FIG. This is the laser beam L scanned by the scanning optical device 31.
is reflected by the reflecting mirror 32 and guided onto the surface of the photosensitive drum 34 in the drum cartridge 33. The electrostatic latent image formed on the photosensitive drum 34 is developed by a developing device (not shown) in the drum cartridge 33, and then transferred to paper fed from the paper feed cassette 35 by a transfer charger 36. The fuser 37
After being fixed by the printer, the paper is discharged by a pair of paper discharge rollers 38. The scanning optical device 31 and the reflecting mirror 3
2 is mounted on a base 39 whose one end is located on the drum cartridge 33.

However, the attachment and detachment of the drum cartridge 33 is
This cannot be done on the sheet feeding/discharging side because of the fixing device 37, and it cannot be done on the upper side because the reflecting mirror 32 and base 39 are fixed. Therefore, as shown in FIG. 6, the printer main body 40 is equipped with a cartridge 33 on a side that intersects with the paper supply side from the paper feed cassette 35 and the paper ejection side from the paper ejection roller pair 38 in the same direction. An opening 41 and a lid body 42 are provided for attachment and detachment.

(Problems to be Solved by the Invention) However, in the case of such a conventional technique, at least two directions are required on the side surface of the printer main body 40: the paper supply/discharge side and the attachment/detachment side of the drum cartridge 33. Therefore, a wide operation space for attaching and detaching the cartridge 33 is required on the side when the paper supply/discharge side is the front. If there are many operating directions on the side of the printer body 40, it is difficult to use the laser beam printer in combination with other equipment when using it as an output printer for a personal computer or a video printer. A problem arises.

Therefore, the present invention was devised to solve the problems of the prior art described above, and its purpose is to provide an image forming apparatus with high operability that can be easily combined with other equipment. Our goal is to provide the following.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an image forming apparatus in which a cartridge having an image bearing member is removable. a movable member, and the movable member is movably provided with an opening for performing the operation, a closed position for covering the opening, and an open position for retracting from the closed position and opening the opening. an optical means for providing information corresponding to the image information to the image carrier; and an optical means provided in the apparatus main body;
The apparatus is characterized in that it has a positioning means for positioning the optical means when the movable member is located at the closed position.

(Example) The present invention will be explained below based on the illustrated example.

The embodiment described below is an electrophotographic image forming apparatus configured to guide a light beam emitted from a scanning optical means to a photosensitive drum surface in a drum cartridge by a reflecting mirror. An opening through which the drum cartridge can be attached and detached is formed on the upper surface, and a movable member is provided to open and close the opening, and the reflector is attached to the movable member, and when the movable member is closed, the reflector is The apparatus is configured to provide a reference surface on the device main body with which the reference surface comes into contact.

Now, FIG. 1 shows a laser beam printer as an embodiment of the present invention.

In the figure, reference numeral 1 denotes a photosensitive drum 2 having a photosensitive layer on its surface used in electrophotography, and a primary charger (not shown) disposed around the photosensitive drum 2.
Drum cartridge with developer and cleaner,
4 is a transfer charger, 5 is a fixing device, and 6 is a paper feed cassette. Reference numeral 7 denotes a paper feed roller which rotates under timing control of the image write signal from the paper feed cassette 6 and feeds the transfer paper 9 to a pair of registration rollers 10. The registration roller pair 10 rotates under timing control so that the phase relationship between the transfer paper 9 and the image on the photosensitive drum 2 matches at the transfer position. 11 is a pair of paper ejection rollers. Reference numeral 12 denotes a scanning optical device, which includes a light source which is a semiconductor laser, a collimator lens for converting the light beam emitted from the light source into a parallel light beam, a polygon mirror which is rotated at a constant rate by a motor, and a photosensitive drum 2 surface. and an imaging lens group for condensing the scanning light beam.

As clearly shown in FIG. 2, the drum cartridge 1 has positioning members 1 disposed on both sides thereof.
The photosensitive drum 2 is pivotally supported by the bearing portion 14 of No. 3. The scanning optical device 12 also includes a positioning member 13.
It is mounted on a base 15 constructed between the two.
The positioning members 13 are formed of strong independent frames that are erected in the printer main body 16 so as to face each other. Note that this positioning member 13 may be integrally molded as a part of the constituent members of the printer main body 16.

In this embodiment, in addition to the above configuration, an opening 17 is formed on the upper surface of the printer main body 16 to which the drum cartridge 1 can be attached and detached, and the opening 17 is opened and closed by an opening/closing lid 18. It's becoming like that. The opening/closing lid 18 is pivotally connected to the printer main body 16 by a hinge 19 so as to be freely openable/closable, and a reflecting mirror 20 is attached to the opening/closing lid 18.
That is, as shown in FIG. 2, a reflector support member 21 made of a plate spring is brought into contact with the back surface of both longitudinal ends of the reflector 20, and the reflector 20 is brought into contact with the tip end of the reflector support member 21. 21a and the intermediate portion 20b. This reflecting mirror support member 2
1 has its base end secured to the back surface of the opening/closing lid 18 via a mounting hole 21c with a screw 22. The positioning member 13 is provided with a reflecting mirror pressing reference surface 23 against which the opposite slope of the reflecting mirror 20 (or the reference surface corresponding to the reflecting surface) comes into contact when the opening/closing lid 18 is closed. When the lid 18 is closed, it is fixed to the printer body 16 by fixing means (not shown) such as hooks and screws.

Although the opening/closing lid 18 is designed to be opened on one side, it may be configured to be opened on both sides or simply detachable from the printer body 16.

When the printer is started, the laser beam L emitted from the scanning optical device 12 is reflected by the reflecting mirror 20 and scanned onto the photosensitive drum 2 to form an electrostatic latent image. At this time, the transfer paper 9 has been previously sent out from the paper feed cassette 8 by the rotation of the paper feed roller 7 whose timing is controlled based on the image signal, and is held between the pair of registration rollers 10. Next, the electrostatic latent image on the drum 2 is developed as a toner image by a developing device and rotated to a transfer charging section. At this time, the transfer paper 9 is sent out by the pair of registration rollers 10 under timing control so that it just reaches the transfer charging section. In this manner, the toner image on the drum 2 is transferred onto the transfer paper by the transfer charger 4, and then fixed through the fixing device 5 and ejected to the outside of the apparatus by a pair of paper ejection rollers 11.

In the above configuration, in the laser beam printer according to this embodiment, the drum cartridge is replaced as follows. In other words, when replacing or inspecting the drum cartridge 1, the first
As shown by the two-dot chain line in the figure, the opening/closing lid 18 is opened outward around the hinge 19, and the drum cartridge 1 is taken out through the opening 17, and the drum cartridge 1 is replaced or inspected, or the jam of the transfer paper 9 is removed. Perform processing, etc. Thereafter, when the drum cartridge 1 is inserted into the printer main body 16 through the opening 17 and the opening/closing lid 18 is rotated counterclockwise around the hinge 19 to close the opening 17, the end of the reflecting mirror 20 The reflective surface contacts the reflective mirror pressing reference surface 23. In this state, the opening/closing lid 18 is not completely closed, and when the opening/closing lid 18 is pressed further, the opening/closing lid 18 completely closes the opening 17 against the spring force of the reflector support member 21, and the fixing means Open/close lid 1
8 is fixed to the printer main body 16. This opening/closing lid 1
8, the reflecting surface of the reflecting mirror 20 is pressed against the reflecting mirror pressing reference surface 23.

As described above, the reflecting mirror 20 is always pressed against the reflecting mirror pressing reference surface 23 provided on the positioning member 13 by the reflecting mirror supporting member 21.
Vibrations, rattles, and slight deformations of the opening/closing lid 18 are absorbed by the reflecting mirror support member 21, and uneven pitch and deviation of the scanning light beam no longer occur. Also, at this time, the drum cartridge 1 is also positioned by the positioning member 13.
Since the photosensitive drum 2 is pivotally supported by a bearing portion 14 provided in the drum cartridge 1, the reproducibility of the drum position and the scanning light beam is good even when the drum cartridge 1 is attached or detached.
Furthermore, even if the casing of the drum cartridge 1 is elastically deformed or dimensional errors occur during assembly, the positional relationship between the reflecting mirror 20 and the photosensitive drum 2 is determined by the positioning member 13, so that It will match. Furthermore, since both ends of the reflecting mirror 20 are pressed against the reflecting mirror pressing reference surface,
Even if the reflecting mirror 20 moves, the reflecting surface is held at a constant position and the imaging position of the scanning light beam does not change.

In addition, in the above embodiment, the reflecting mirror support member 21
In addition to a leaf spring, the reflecting mirror 20 may be formed of rubber, urethane foam, or plastic integrally molded with the opening/closing lid 18, as long as it elastically supports and fixes the reflecting mirror 20 to the opening/closing lid 18.

FIG. 3 shows another embodiment of the mounting structure for the reflecting mirror, and the same parts as in the previous embodiment will be described with the same reference numerals. In this embodiment, an iron piece 24 is provided on the reflector pressing reference surface 23 of the positioning member 13.
is fixed, and a magnet piece 25 is fixed to the reflecting surface of the reflecting mirror 20 that comes into contact with this. Therefore, the magnet piece 25 of the reflecting mirror 20 is attracted to the iron piece 24 of the reflecting mirror pressing reference surface 23, and it is possible to prevent the reflecting mirror 20 from moving independently of the reflecting mirror pressing reference surface 23 due to external vibrations. .

FIG. 4 shows still another embodiment of the mounting structure for the reflecting mirror. In this embodiment, the opening/closing lid 18
A hollow mirror holder 26 is fixed to the mirror holder 26, and a reflecting mirror 20 is embedded in the mirror holder 26 via an elastic member 27 such as a sponge, and a magnet piece 25 is fixed to the reflective surface of the reflecting mirror 20. .
In this case, when the opening/closing lid 18 is set at a predetermined position, the reflecting mirror 20 does not come into contact with the mirror holder 26, and vibrations from the outside can be prevented from being transmitted to the reflecting mirror 20 via the opening/closing lid 18.

The positional relationship between the magnet piece and the iron piece may be reversed, and magnets of different polarities may be provided on the reflecting mirror and the positioning member, respectively. As a result, the reflecting mirror is firmly fixed to the positioning member by the attraction force of the magnet and the pressing force of the reflecting mirror supporting member.
and accurately positioned.

This embodiment has the above-mentioned structure and operation, and includes an opening on the top surface of the main body of the device to which the drum cartridge can be attached and removed, a reflector attached to the movable member that opens and closes the opening, and the movable member closed. When this happens, the reference surface of the reflecting mirror is brought into contact with the reference surface of the main body of the device. Therefore, even though the reflector is attached to the movable member, the reflector can be positioned accurately, and the reflector positioned above the drum cartridge can be moved together with the movable member to allow the drum cartridge to be attached and removed upward. . Therefore, it is only necessary to provide a section on the side of the main body for feeding and discharging paper on one side, and it can be connected to other devices from three sides and the bottom, improving operability and providing flexibility in arrangement with other devices. This increases flexibility and allows for effective use of space.

(Effects of the Invention) As described in detail above, according to the present invention, since the cartridge can be attached and removed from above the apparatus main body, the surrounding restrictions when installing the apparatus can be further reduced. Moreover, even though the cartridge can be installed from above the apparatus main body, the optical means can be positioned with high precision, so that an image forming apparatus of higher quality can be provided.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional front view showing a laser beam printer as an embodiment of the image forming apparatus according to the present invention, FIG. 2 is a perspective view showing the mounting structure of a reflecting mirror, and FIG. 3 is a perspective view showing the mounting structure of the reflecting mirror. FIG. 4 is a vertical cross-sectional view showing still another example of the mounting structure for the reflecting mirror, FIG. 5 is a vertical cross-sectional front view showing a conventional laser beam printer, and FIG. 6 is a perspective view showing the external appearance of the device shown in FIG. 5. FIG. Explanation of symbols, 1...Drum cartridge, 2...
...Photosensitive drum, 12...Scanning optical device, 13...
Positioning member, 16...Printer main body, 17...
Opening, 18...Opening/closing lid, 20...Reflector, 21
...Reflector support member, 23...Reflector pressing reference surface.

Claims (1)

[Claims for Utility Model Registration] (1) An image forming apparatus in which a cartridge having an image bearing member can be attached and detached, comprising: an opening for attaching and detaching the cartridge provided on the upper surface of the apparatus main body; and an opening for attaching and detaching the cartridge. a movable member movable between a closed position for covering and an open position for retracting from the closed position and opening the opening; An image forming apparatus comprising: an optical means for applying to a carrier; and a positioning means provided on an apparatus main body for positioning the optical means when the movable member is located at the closed position. (2) The image forming apparatus according to claim (1), wherein the cartridge includes, in addition to the photosensitive drum as the image carrier, a charger that acts on the photosensitive drum. (3) The image forming apparatus according to claim (1), wherein the cartridge includes, in addition to the photosensitive drum as the image carrier, a developing device that acts on the photosensitive drum. (4) The cartridge has, in addition to the photosensitive drum as the image bearing member, a cleaner that acts on the photosensitive drum.
The image forming apparatus described in . (5) The image forming apparatus according to claim (1), wherein the optical means is a reflecting mirror. (6) The image forming apparatus according to claim (1), wherein the image forming apparatus is a laser beam printer.