JP2003011412A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus wherein freedom of placing a light scanning unit is increased to readily attain an optimum position for the high performance and a moving space for attaching or detaching of a process cartridge can be effectively used. SOLUTION: This image forming apparatus comprises the light scanning unit 10 having a semiconductor laser device, a collimate lens, a deflector such as a polygon mirror and a scanning lens which are united therein and a process cartridge 20 having a photosensitive drum 21 (photosensitive body) and toner which are united therein. The light scanning unit 10 is so constituted that the light scanning unit can be displaced between a position for executing optical writing to the photosensitive drum 21 and a position for not executing the optical writing thereto.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic laser printer or laser FAX.

[0002]

2. Description of the Related Art FIG. 5 shows a schematic cross section of an image forming apparatus.

The image forming apparatus shown in FIG. 5 uses a laser beam to write on a photosensitive member for an electrostatic latent image.
In recent years, in most cases, the developing device, the photosensitive drum 21, the toner, and the like are integrated into a unit, and the process cartridge 20 is replaceable. Then, they are replaced on the main body 30 according to the consumption of the toner and the photosensitive drum 21 corresponding to the printing frequency. The process cartridge 20 is inserted / removed through the cartridge movement path 25 inside the dotted line shown in the main body 30.

On the other hand, the optical scanning unit 10 in the main body 30 of the image forming apparatus includes, as is well known, a semiconductor laser (shown by a dotted line) 4, a collimator lens and a cylinder lens (both not shown). ), Or while the scanning lens 2 and the folding mirror 5 are provided, the laser beam 7 is deflected and scanned by a deflector such as a polygon mirror 12 to perform an optical writing operation on the photosensitive drum 21 inside the process cartridge 20.

The optical scanning unit 10 is entirely covered with a box-shaped optical box 3, and the optical scanning unit 10 is installed on a frame in the apparatus body 30 or on the installation table 12 in order to ensure high printing quality. The reference adjustment pin 8 is used to perform high-precision positioning and attachment with screws or the like.

Further, the image forming apparatus main body 30 is provided with a control circuit unit 31, a paper feed tray 34 containing print paper, a paper feed roller 35, a fixing unit 36, a paper discharge roller 37, etc. A paper discharge tray 38 and the like on which the scraped paper 60 is placed are provided.

[0007]

However, in the above-mentioned conventional example, it is premised that the optical scanning device unit is fixed at one installation position in the image forming apparatus, and the developing device, the photoconductor and the toner are fixed. Since it is only uniquely placed in the vicinity of the process cartridge configured to be integrated and replaceable, there are many restrictions on the degree of freedom in selection. These are, for example, the case where they are installed at the top of the image forming apparatus, etc., and the heat from the fixing device is likely to collect and there are cases where the temperature is high. Sometimes it wasn't very good for me.

On the other hand, other parts including the optical scanning device unit cannot be installed in the path for attaching and detaching the process cartridge in the main body of the image forming apparatus, which hinders effective use of the volume of the image forming apparatus. It was

The present invention has been made in view of the above problems, and an object thereof is to increase the degree of freedom of installation of an optical scanning unit and to easily secure an optimum position where performance can be exhibited. An object of the present invention is to provide an image forming apparatus that can effectively use a moving space for attaching and detaching a process cartridge.

[0010]

In order to achieve the above object, the present invention provides a semiconductor laser, a collimating lens, and
In an image forming apparatus including a process cartridge in which a deflector such as a polygon mirror and a scanning lens are integrated, and a photoconductor and a toner are integrated, the optical scanning unit is a photoconductor inside the device. It is characterized in that it can be installed by being displaced between a position where optical writing is performed and a position where optical writing is not performed.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> FIGS. 1 and 2 are cross-sectional views of an image forming apparatus according to a first embodiment of the present invention. In these drawings, 40 is an installation reference stay, 41 is a rotary moving base, 42 is a guide plate, 43 is a guide rail mechanism, and 50 and 51 are moved optical scanning units. still,
Other configurations are the same as those of the conventional image forming apparatus shown in FIG.

Main body 3 of the image forming apparatus according to the present embodiment
Reference numeral 0 denotes a process cartridge 20, and the optical scanning unit 10 is located slightly above the process cartridge 20.

Here, the feature of this embodiment is that it is provided with a mechanism for moving the optical scanning unit 10, and the optical scanning unit 10 can also be moved to a place other than the position where writing is performed.

As shown by the solid line in FIG. 1, the optical scanning unit 10 has an installation reference stay 4 at a prescribed position during normal use.
Although the optical scanning unit 10 is fixed to 0, the optical scanning unit 10 can be moved to the position of the optical scanning unit 50 indicated by the alternate long and short dash line, and the rotary movement base 41 and the optical scanning unit 10 move integrally. By providing such a mechanism, the optical scanning unit 10 can be arranged at a relatively arbitrary position. For example, the fixing unit is located on the left side of the drawing, and the heat of the fixing heater also flows into the main body. However, as described above, it is possible to dispose at a position slightly lower than the position where the temperature is relatively high above the inside of the main body 30. Due to these configurations, it is easy to select a position where the performance of the optical scanning unit 10 is easily exhibited.

On the other hand, during normal use, the optical scanning unit 10
Is in the movement path 25 of the process cartridge 20, but when the process cartridge 20 is attached or detached, the optical scanning device moves upward in the drawing, and the process cartridge 2
The feature is that it is a form that is avoided from the movement route 25 of 0. Further, these mechanisms are different from those having a large-scale mechanism in which the entire apparatus is largely divided into upper and lower bodies to open and close like some image forming apparatuses.

Here, the optical scanning unit 10 includes a main body 30.
It may be configured to be manually moved from the outside, and when the process cartridge 20 is attached or detached, a part of the process cartridge 20 and a part of the exterior part of the optical scanning unit 10 are in contact with each other and pushed so as to move each other. May be

Further, the movement of the optical scanning unit 10 is performed by the main body 3
It is better to use the frame that makes up 0
It is assumed that a fulcrum for rotation of the optical scanning unit 10 and a beam portion for supporting the weight of the optical scanning unit 10 are integrally formed in the 0 frame.

Further, in the initial mounting of the optical scanning unit 10 to the main body 30, the position of the reference adjusting pin 8 of the optical scanning unit 10 is adjusted in advance by a jig and fixed in the unit, and the apparatus main body 30 is fixed. The reference adjusting pins 8 are brought into contact with a predetermined position (the rotary moving base 41 in the present embodiment) of the main body frame inside to fix and attach the attitude and position of the optical scanning unit 10. Then, when the optical scanning unit 10 moves as described above, the reference adjusting pin 8 and the installation reference stay 40 and the like are integrated as a whole and the rotary moving table 41 is provided.
Is displaced with. With these configurations, the installation accuracy of the optical scanning unit 10 is maintained.

Next, as shown in FIG. 2, the optical scanning unit 10 is provided with another mechanism that can be displaced from its position while being placed in the movement path 25 of the process cartridge 20 during normal use. They are for sliding the guide rail mechanism 43 in the main body 30 shown in FIG. 2 and the guide plate 42 formed on a part of the outer shape of the optical scanning unit 10 in contact with each other. Here, the guide plate 42 may also have the function of the reference adjustment pin 8, or they may be provided separately. In these cases as well, the optical scanning unit 10 can be moved within the main body 30 similarly to the above-described configuration, but the moving range is larger and there is a degree of freedom.

Here, the optical scanning unit 10 is composed of a semiconductor laser, a collimator lens, a cylinder lens, a deflector such as a polygon mirror, a scanning lens, a BD sensor, a folding mirror, etc., provided inside as described above. However, a part may be outside the box-shaped unit, and some parts such as a folding mirror may be installed outside. Further, the semiconductor laser may be of a so-called multi-beam scanning system in which a plurality of light emitting points are provided and a plurality of light emitting points are simultaneously written.

As described above, the space inside the main body 30 can be effectively used to promote compactness.

<Second Embodiment> Next, a second embodiment of the present invention will be described.

FIG. 3 is a sectional view of the image forming apparatus according to the present embodiment. In this figure, 39 is an outer upper cover which also serves as a paper discharge tray, 45 is a contact plate, and 52 is a moved optical scanning unit. . The other structure is the same as that of the first embodiment. Further, in FIG. 3, the paper feed tray and the like under the image forming apparatus are not shown.

Thus, in the image forming apparatus according to the present embodiment, although the optical scanning unit 10 moves within the main body 30 as in the first embodiment, a part of the main body 30 is used. It is characterized in that a certain outer cover 39 is partially projected and moved as the optical scanning unit 10 is displaced.
As shown in FIG. 3, these parts are provided with a contact member such as a contact plate 45 on a part of the rotary movement base 41 to which the optical scanning unit 10 is attached, and push up the outer cover 39.

Although the outer upper cover 39 in this embodiment has the same function as the paper discharge tray 39 in the first embodiment, it is not limited thereto. Also, these mechanisms are not premised on those having a large-scale mechanism in which the entire device is largely divided into upper and lower parts to open and close as in the first embodiment, but only a part of the external cover. Is in the form of displacement.

Thus, the effect peculiar to this embodiment is that it is effective when the entire image forming apparatus is made small and compact.

<Third Embodiment> Next, a third embodiment of the present invention will be described.

FIG. 4 is a sectional view of the image forming apparatus according to the present embodiment. In FIG. 4, reference numeral 26 is another moving path of the process cartridge 20, and 53 and 54 are moved optical scanning units. The other structure is the same as that of the first embodiment.

In this embodiment, the optical scanning unit 10 moves within the main body 30 as in the first and second embodiments, but the moving position of the optical scanning unit 10 when not writing is the main body 30. It is characterized by extending to the outside of.
As shown in FIG. 4, the structure is such that the optical scanning unit 10 is normally positioned in the movement path 25 of the process cartridge 20 but is moved to the position of the moved optical scanning unit 53, and the guide in the first embodiment is used. Rail mechanism 43
Etc. are used.

Next, the area surrounded by the chain double-dashed line is the movement path 26 of the other process cartridge, but these show the case where the process cartridge 20 is detached from above the main body 30. In this case, the optical scanning unit 10 moves to the moved position of the optical scanning unit 54 when the process cartridge 20 is attached or detached, but the moving amount thereof is relatively small. These mean that the direction of attachment / detachment of the process cartridge 20 in the main body 30 and the direction of movement of the optical scanning unit 10 can be selected comparatively arbitrarily in terms of design, and the degree of freedom in the overall arrangement that is most easily exerted in the performance of the image forming apparatus. have.

The effect peculiar to this embodiment is that the movement of the optical scanning unit 10 extends outside the apparatus (the degree of freedom is widened).
Because of the configuration, the image forming apparatus can be made more compact.

[0033]

As is apparent from the above description, according to the present invention, a semiconductor laser, a collimator lens, a deflector such as a polygon mirror, and an optical scanning unit in which a scanning lens is integrated are provided. In an image forming apparatus including a body and a process cartridge in which toner is integrated, the optical scanning unit can be installed by being displaced between a position where optical writing is performed on a photoconductor and a position where optical writing is not performed inside the device. As a result, it is possible to increase the degree of freedom in the installation of the optical scanning unit and to easily secure the optimum position where performance can be exhibited, and it is possible to effectively use the moving space for attaching and detaching the process cartridge. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the image forming apparatus according to the first embodiment of the present invention.

FIG. 3 is a sectional view of an image forming apparatus according to a second embodiment of the present invention.

FIG. 4 is a sectional view of an image forming apparatus according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a conventional image forming apparatus.

[Explanation of symbols]

1 polygon mirror 8 Reference adjustment pin 10 Optical scanning unit 20 process cartridges 21 Photosensitive drum 25 Process cartridge movement path 30 Image forming apparatus main body

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2C362 AA42 AA45 BA90 DA01 DA02                       DA04 EA00                 2H071 AA26 AA35 BA03 BA04 BA13                       BA14 BA15 BA19 DA02 DA08                       DA15 EA04                 2H076 AB05 AB12 EA11                 5C072 AA03 BA02 HA13 JA07 MA01                       MB04 XA05

Claims (6)

[Claims] 1. A semiconductor laser, a collimating lens,
In an image forming apparatus including a deflector such as a polygon mirror and an optical scanning unit in which a scanning lens is integrated, and a process cartridge in which a photoconductor and a toner are integrated, the optical scanning unit is a photoconductor inside the device. An image forming apparatus, which can be installed while being displaced between a position where optical writing is performed and a position where optical writing is not performed. 2. The optical scanning unit is configured to perform an optical writing operation while being installed in a process cartridge attachment / detachment path, and is provided with a mechanism for avoiding the process cartridge movement path when the process cartridge is moved. The image forming apparatus according to claim 1, wherein the image forming apparatus comprises: 3. The optical scanning unit installed on the attachment / detachment path of the process cartridge is provided with a mechanism that moves only within the main body, and the movement of the optical scanning unit is attached to a rotary table or the like for movement. 3. The image forming apparatus according to claim 1 or 2, wherein the guide rail mechanism does not include a mechanism that slides and moves, and the entire exterior portion is largely divided and opened and closed. 4. The optical scanning unit installed on the attachment / detachment path of the process cartridge is provided with a mechanism for moving inside the apparatus, and at the time of moving them, a part of the exterior part of the apparatus is partially Displacement to the outside 1.
The image forming apparatus according to any one of 1 to 3. 5. The optical scanning unit installed on the attachment / detachment path of the process cartridge is provided with a mechanism in which a part of the outer shape of the optical scanning unit projects and moves to the outside of the apparatus. The image forming apparatus according to any one of claims. 6. The image forming apparatus according to claim 1, wherein the optical scanning unit has a plurality of light emitting points and multi-beam writing is performed.