JP2001133715A - Supporting structure for scanning type optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a vibration like pendulum motion of a diffraction optical device in a subscanning direction. SOLUTION: The optical box 25 of a scanning type optical device 21 is provided with a horizontal box part 26 nearly horizontally placed on the upper surface of a 1st stay 24, and a vertical box part 27 extended nearly vertically downward from either end of the box part 26 and inserted through the mount hole 24a of the 1st stay 24. A laser beam source 31, a condensing lens 32, a deflection scanner 33, a scanning lens 34, and a reflecting mirror 35 are arranged in the box part 26, and a diffraction optical device 36 is arranged in the box part 27. The side plates 27a and 27b of the box part 27 near the optical device 36 are supported on the 2nd stay 41 laid between supporting plates 22 and 23 through brackets 42 and 43. The plates 27a and 27b are fixed on the optical box 25 and the 2nd stay 41 after they are adjusted with respect to the optical box 25 and the 2nd stay 41 by the brackets 42 and 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning optical device supporting structure for supporting a scanning optical device on an image forming apparatus such as an electrophotographic copying machine.

[0002]

2. Description of the Related Art As shown in FIGS. 6 and 7, in a conventional image forming apparatus, a scanning optical device 1 is supported on a side plate 2 via a stay 3, and a photosensitive drum 4 is provided below the stay 3. A provided drum cartridge 5 is arranged, and a toner cartridge 6 is arranged near the drum cartridge 5.

The scanning optical device 1 has an optical box 11 supported by a stay 3, and the optical box 11 has a stay 3.
And a vertical box 11b inserted into the mounting hole 3a of the stay 3 is provided. A laser light source 12, a cylindrical lens 13, a polygon mirror 1 are provided in a horizontal box portion 11a of the optical box 11.
4, a drive motor 15, a scanning lens 16, and a folding mirror 17 are arranged, and a diffractive optical element 18 is arranged in a vertical box portion 11b of the optical box 11.

[0004]

However, in the conventional image forming apparatus, since vibrations are generated from various driving motors and driving force transmitting mechanisms, the stay 3, the optical box 11, the optical elements, and the like vibrate. In particular, since the stay 3 vibrates in the vertical direction, the diffractive optical element 1 in the vertical box portion 11b of the optical box 11 is
Reference numeral 8 vibrates like a pendulum in the sub-scanning direction, and the position of the laser beam incident on the photosensitive drum 4 fluctuates greatly. The pendulum-shaped vibration of the diffractive optical element 18 greatly affects the image quality as compared with the vibration of other optical elements.
It is important to suppress pendulum-like vibration in the sub-scanning direction.

An object of the present invention is to solve the above-mentioned problems,
It is an object of the present invention to provide a support structure of a scanning optical device which can suppress a pendulum-like vibration of a diffractive optical element in a sub-scanning direction.

[0006]

In order to achieve the above object, a supporting structure of a scanning optical device according to the present invention comprises a laser light source and a laser beam from the laser light source for forming an image in a sub-scanning direction. A lens, a deflection scanner for deflecting and scanning the laser light from the condenser lens in the main scanning direction, a scanning lens for condensing the laser light from the deflection scanner, and transmitting the laser light from the scanning lens In the case of supporting a scanning optical device including a diffractive optical element and an optical box, the main body of the optical box is supported by a support,
The optical box is further supported by the support near the diffractive optical element.

Further, the supporting structure of the scanning optical device according to the present invention comprises a laser light source, a condenser lens for forming an image of the laser light from the laser light source in the sub-scanning direction, and a laser light from the condenser lens. In the case of supporting a scanning optical device in which a deflection scanner for deflecting and scanning in the main scanning direction and a scanning lens for condensing laser light from the deflection scanner are arranged in an optical box, The main body is supported by a first support, and a diffractive optical element that transmits laser light from the scanning lens is directly supported by a second support.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is a partially cutaway perspective view of the first embodiment. A scanning optical device 21 includes a first stay 2 on opposite support plates 22 and 23 of an image forming apparatus.
4 is supported. Below the first stay 24, a drum cartridge (not shown) including a photosensitive drum on which laser light from the scanning optical device 21 is incident is arranged, and a toner cartridge is arranged near the drum cartridge.

The optical box 25 of the scanning optical device 21 has a first
Horizontal box 26 placed substantially horizontally on the upper surface of the stay 24
And a vertical box portion 27 extending substantially vertically downward from one end of the horizontal box portion 26 and inserted through the mounting hole 24a of the first stay 24. The outer shape of the optical box 25 is substantially L-shaped. It is in the shape.

In the horizontal box portion 26 of the optical box 25, a laser beam for imaging the laser beam from the laser beam source 31 in the sub-scanning direction in the main scanning direction along the optical path of the laser beam source 31 for emitting the laser beam. A deflection scanner 33 that performs deflection scanning;
A scanning lens 34 for forming an image of the laser beam and a folding mirror 35 for folding the laser beam toward the photosensitive drum are arranged.

The deflection scanner 33 comprises a polygon mirror 33a and a polygon motor 33b. A lid (not shown) is attached to the horizontal box 26 of the optical box 25, and the horizontal box 26 is fixed to the first stay 24. It is fixed with screws and the like.
In the vertical box 27 of the optical box 25, a diffractive optical element 36 for transmitting the laser beam from the turning mirror 35 is arranged.

The lower part of the vertical box 27 of the optical box 25 is provided with a second stay 4 provided between the support plates 22 and 23.
1 is supported via brackets 42 and 43.
The vertical box 27 has side plates 27a and 27b facing the support plates 22 and 23, respectively, and the second stay 41 is formed with an opening 41a through which the laser light from the diffractive optical element 36 passes. Then, the brackets 42 and 43 are respectively disposed on the side plates 27a and 27b of the vertical box 27, and after being adjusted with respect to the vertical box 27 and the second stay 41, the brackets 42 and 43 are fixed thereto by fixing screws or the like. I have.

FIG. 2 shows the vibration frequency Hz of the diffractive optical element 36.
FIG. 9 is a graph showing the displacement amount μm in the sub-scanning direction with respect to FIG. 7, wherein a curve a shows a conventional example in which the lower portion of the optical box 25 is not supported by the second stay 41 and the brackets 42 and 43; 25 shows a first embodiment in which the lower portion of the support 25 is supported by a second stay 41 and brackets 42 and 43.

As can be seen from this graph, in the first embodiment, the pendulum-like vibration of the diffractive optical element 36 can be suppressed, and the displacement μm in the sub-scanning direction of the diffractive optical element 36 is made larger than in the conventional example. Can be suppressed. At this time, if a damping material is interposed between the second stay 41 and the brackets 42 and 43 or between the brackets 42 and 43 and the vertical box 27, the vertical box 27 Can be further suppressed.

FIG. 3 shows a second embodiment, in which a vertical box 27 of an optical box 25 is supported by supporting plates 22 and 23 on a side of a diffractive optical element 36.
4, 45 support. This second embodiment can also achieve the same effects as the first embodiment.

FIG. 4 shows a third embodiment. A window 22 through which an optical box 25 is inserted in a horizontal direction is provided on one support plate 22 '.
a is formed. The mounting hole 24a of the first stay 24 'communicates with the window 22a of the support plate 22'.
The stay 24 ′ is integrally provided with a holding plate 24 b for holding the upper surface of the horizontal box 26 of the optical box 25.

The vertical box 27 of the optical box 25 has an opening 46a.
And is supported by brackets 47 and 48 on a second stay 46 provided between the support plates 22 ′ and 23. For example, two pins 49 that can be fitted into holes (not shown) formed in the side plate 27b of the vertical box 27 are provided in advance on the bracket 48 located at the back of the mounting hole 24a,
Further, the bracket 48 is fixed to a predetermined position of the second stay 46 in advance.

When the optical box 25 is inserted in the direction of the arrow into the mounting hole 24a of the first stay 24 'through the window 22a of the support plate 22', the bracket 48 is inserted into the hole of the side plate 27b of the optical box 25. The pin 49 is fitted and the side plate 27b contacts the bracket 48, so that the movement of the optical box 25 is stopped. Then, from the front, the other bracket 47
Is inserted, and the bracket 47 is fixed to the optical box 25 and the second stay 46 with fixing screws or the like. Also in the third embodiment, the addition of the vibration damping material is effective, and the same effect as in the first embodiment can be achieved.

FIG. 5 shows a fourth embodiment, in which the diffractive optical element 36 is removed from the optical box 25, and the second stay 50 is provided between the side plates 22 and 23 with an opening 50a.
It is supported via brackets 51 and 52. In addition,
The shape of the optical box 25 is substantially the same as that of the first embodiment for dust prevention. Also in the fourth embodiment, the addition of the vibration damping material is effective, and the same effect as in the first embodiment can be achieved.

[0020]

As described above, in the scanning optical device according to the present invention, since the optical box is supported by the support near the diffractive optical element, the pendulum-shaped vibration of the diffractive optical element in the sub-scanning direction is reduced. Thus, the irradiation position of the laser beam can be stabilized.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a first embodiment.

FIG. 2 is a graph showing a displacement amount with respect to a vibration frequency of a diffractive optical element.

FIG. 3 is a partially cutaway perspective view of a second embodiment.

FIG. 4 is a partially cutaway perspective view of a third embodiment.

FIG. 5 is a partially cutaway perspective view of a fourth embodiment.

FIG. 6 is a partially cutaway perspective view of a conventional example.

FIG. 7 is a sectional view of a conventional example.

[Explanation of symbols]

 Reference Signs List 21 scanning optical device 22, 22 ', 23 support plate 22a window 24, 24' first stay 24a mounting hole 24b holding plate 25 optical box 26 horizontal box 27 vertical box 27a, 27b side plate 31 laser light source 32 Optical lens 33 Deflection scanner 34 Scan lens 35 Folding mirror 36 Diffractive optical element 41, 44, 45, 46, 50 Second stay 42, 43, 47, 48, 51, 52 Bracket 49 pin

Claims (7)

[Claims] 1. A laser light source, a condenser lens that forms an image of laser light from the laser light source in a sub-scanning direction, a deflection scanner that deflects and scans the laser light from the condenser lens in a main scanning direction, When supporting a scanning optical device having a scanning lens for condensing laser light from the deflection scanner and a diffractive optical element for transmitting laser light from the scanning lens in an optical box, A supporting structure for a scanning optical device, wherein a main body of a box is supported by a support, and the optical box is further supported by the support near the diffractive optical element. 2. A folding mirror that folds the laser beam from the deflection scanner is disposed in the optical box, wherein the optical box has a first box portion as the main body having an optical path to the folding mirror, A second box portion having an optical path from the folding mirror and having the diffractive optical element arranged thereon, forms a substantially L-shaped outer shape, and the first box portion and the second box portion are respectively provided on the support. The supporting structure of the scanning optical device according to claim 1, which is fixed. 3. The method according to claim 2, wherein the first box portion is supported by the support via a first stay, and the second box portion is supported by the support via a second stay. A support structure for the scanning optical device as described in the above. 4. The supporting structure for a scanning optical device according to claim 3, wherein said second box portion is fixed to said second stay near said diffractive optical element. 5. The first stay has a structure for receiving the optical box from a lateral direction, and the second box portion and the second box are connected to each other.
4. The support structure for a scanning optical device according to claim 3, wherein the stays are fixed via a fixing member at a front portion and a rear portion of the optical box in the direction of entry. 6. The support structure for a scanning optical device according to claim 5, wherein the fixing member located at a front part of the optical box in the approach direction has a pin portion that fits into a hole formed in the optical box. . 7. A laser light source, a condenser lens that forms an image of the laser light from the laser light source in the sub-scanning direction, a deflection scanner that deflects and scans the laser light from the condenser lens in the main scanning direction, When supporting a scanning optical device in which a scanning lens for condensing laser light from the deflection scanner is arranged in an optical box, the main body of the optical box is supported on a first support, A supporting structure for a scanning optical device, wherein a diffractive optical element that transmits laser light from the scanning lens is directly supported by a second support.