JPH10153745A - Deflection scanning device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent a screw fixing a positioning member from being accidentally loosened. [Structure] Flanges 41 on both sides of optical box 21 have
A positioning member 35 for positioning the optical box 21 on the main body frame 31 is fixed with screws 34. Cover 29
The main body 29a is provided with a horizontal concealing portion 29b extending substantially horizontally above the positioning member 35. With the cover 29 removed, the reference pin 35b of the positioning member 35 is fitted into the reference hole formed in the flange portion 41, and the optical box 21 is moved to adjust the laser beam to irradiate a predetermined position on the photosensitive drum. I do. After that, screw 34 is tightened and cover 2
9 is attached. The reference pin 35b of the positioning member 35 is fitted in the reference hole 31a of the main body frame 31 and fixed by screws. The horizontal concealing portion 29b of the cover 29 conceals above the screw 34, and prevents the screw 34 from being loosened by a tool.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an image forming apparatus such as a laser printer and a laser facsimile, and deflects a light beam from a light source by a polygon mirror and scans a photosensitive drum by a scanning lens. It is about.

[0002]

2. Description of the Related Art Conventionally, as shown in a plan view of FIG. 9 and a side view of FIG. 10, a cover 2 is put on an optical box 1 containing a polygon mirror and the like. And is fixed by screws 3.
This type of optical box 1 is used by being attached to a main body frame 4 of an image forming apparatus. A photoconductor drum (not shown) is provided on the main body frame 4.
The optical box 1 is positioned on the main body frame 4 so that the light beam scans a predetermined position on the photosensitive drum, and is fixed by screws 5. At this time, the optical box 1 is extremely highly accurate with respect to the main body frame 4, for example, 0.1 mm.
It is positioned with a dimensional tolerance of not more than mm.

For this reason, a positioning member 6 is fixed to a flange portion 11 protruding from both sides of the optical box 1 by a screw 7. The flange portion 11 has an elongated screw insertion hole 12 through which the screw 5 is inserted, a reference hole (not shown) into which the reference pin 6a of the positioning member 6 is inserted, and a positioning member 6.
And a screw hole (not shown) for screwing the screw 7 through a screw insertion hole (not shown). At this time, the optical box 1
The diameter of the reference hole is made larger than the diameter of the reference pin 6a of the positioning member 6, and the position of the positioning member 6 is finely adjusted by making the screw insertion hole of the positioning member 6 a long hole. I have.

The reference pin 6a of the positioning member 6 is
The optical box 1 is adjusted so that the light beam can irradiate a predetermined range of the photosensitive drum, and then the screw 7 is tightened to fix the positioning member 6 to the optical box 1. You. In the optical box 1 in which the position of the positioning member 6 has been adjusted, the position of the optical box 1 with respect to the main body frame 4 is accurately determined only by fitting the reference pin 6a into the reference hole 4a of the main body frame 4. Then, the screws 5 are tightened to fix the optical box 1 to the main body frame 4.

[0005]

As described above, since strict position adjustment is conventionally performed on the positioning member 6, it is not permissible to loosen the screw 7 fixing the positioning member 6 in the case of repair or the like. . For this reason, when it becomes necessary to remove the optical box 1 from the main body frame 4, it is sufficient to loosen only the screw 5 that fixes the optical box 1. However, since the screw 5 fixing the optical box 1 and the screw 7 fixing the positioning member 6 are close to each other, the screw 7 fixing the positioning member 6 erroneously.
May be loosened. In this case, it is necessary to return the optical box 1 to the factory and readjust the position of the positioning member 6 using a dedicated jig, so that the time and labor for transporting the optical box 1 and adjusting the positioning member 6 increase. I do. For this reason, the repairer needs to be very careful not to loosen the screw 7 fixing the positioning member 6 when repairing the failure.

In order to cope with such a problem, it is conceivable to provide the positioning member 6 inside the optical box 1.
When the distance between the positioning members 6 is reduced, a new problem that mounting accuracy is deteriorated occurs. It is also conceivable to apply red paint to the head of the screw 7 for fixing the positioning member 6 to call attention, but the effect of calling attention is sufficient for the time required to apply the paint. There is also a problem that is not.

An object of the present invention is to provide a deflection scanning device which solves the above-mentioned problems and prevents the fixing means of the positioning member from being loosened by mistake.

[0008]

A deflection scanning device according to the present invention for achieving the above object comprises a light source for emitting a light beam, a polygon mirror for deflecting the light beam from the light source, and a polygon mirror. A drive motor that rotates and a scanning lens that scans the photosensitive member with the light beam from the polygon mirror is attached to an optical box, the optical box having a positioning member having a cover and fixed by fixing means, In a deflection scanning device in which an optical box is positioned by the positioning member and assembled to an assembly, the optical scanning box has a concealing means for concealing the positioning member.

[0009]

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 plan view of the first embodiment with a cover removed. For example, a semiconductor laser light source 22 that emits laser light is arranged at a predetermined position in an optical box 21. In the traveling direction of the laser light, a cylindrical lens 23 for condensing the laser light linearly, and a cylindrical lens 2
And a polygon mirror 24 for deflecting the laser light from No. 3 in order. The polygon mirror 24 is supported so as to be driven to rotate at a high speed by a drive motor 25,
It deflects the laser light.

A scanning lens 26 is disposed in the traveling direction of most of the laser light deflected by the polygon mirror 24, and a recording start synchronization signal is provided in the traveling direction of a part of the laser light deflected by the polygon mirror 24. A light detection lens 27 and a light detection sensor 28 for obtaining are provided. These members 22 to 28 are accurately fixed at predetermined positions of the optical box 1 using a special tool at a factory.

As shown in the plan view of FIG. 2, a cover 29 is put on the optical box 21, and the cover 29 is fixed to the optical box 21 by screws 30. As shown in the side view of FIG. 3, the optical box 21 is provided with a screw 33 so that the laser beam scans a predetermined position on a photosensitive drum 32 provided on the main body frame 31 of the image forming apparatus. Is to be fixed by. At this time, the optical box 2
1 is positioned with extremely high precision, for example, a dimensional tolerance of 0.1 mm or less, via a positioning member 35 fixed by screws 34. As shown in FIG. 4, a reference pin 35b is provided to be orthogonal to the plate-shaped main body 35a of the positioning member 35, and a screw insertion hole 35c through which the screw 34 is inserted is provided.

In order to fix the optical box 21 to the main body frame 31 and to position and fix the positioning member 35 to the optical box 21, flange portions 41 are provided on both side surfaces of the optical box 21. Screw 33 on the flange 41
, A reference hole 43 into which the reference pin 35b of the positioning member 35 is inserted, and a screw hole 44 into which the screw 34 is screwed. At this time, the diameter of the reference hole 43 of the optical box 21 is
The diameter of the reference pin 35b is made larger and the screw insertion hole 35c of the positioning member 35 is elongated, so that the position of the positioning member 35 can be finely adjusted with respect to the optical box 21. The optical box 21 is provided with a positioning pin 45 that fits into a reference hole (not shown) of the cover 29 and a screw hole 46 into which the screw 30 is screwed.

The rectangular main body 29a of the cover 29
The horizontal concealing portions 29 that extend substantially horizontally above the positioning member 35 and conceal the positioning member 35
The horizontal hiding portions 29b are provided to prevent the screws 34 from being loosened by the jig.

When positioning and fixing the positioning member 35 to the optical box 21, adjustment is performed with the cover 29 removed from the optical box 21. At this time, the reference pin 35b of the positioning member 35 is fitted into the hole of the dedicated jig, and the optical box 21 is
Is slightly moved in the xy directions, and the laser beam is
After scanning within the predetermined range of 2, the screw 34 is tightened. After that, the positioning pins 45 of the optical box 21 are used.
Into the reference hole of the cover 29, and the screw 30 into the screw hole 46.
Then, the cover 29 is fixed to the optical box 21. Then, when assembling the optical box 21 to the main body frame 31, the reference pin 35b of the positioning member 35 is fitted into the reference hole 31a of the main body frame 31, and the screw 33 is tightened.

As described above, in the first embodiment, the cover 29
The upper portion of the positioning member 35 can be concealed by the horizontal concealing portion 29b provided in the main body 29a, so that the jig can be prevented from being applied to the screw 34 and the screw 34 can be prevented from being loosened accidentally. Thus, it is possible to prevent the strict position adjustment of the positioning member 35 from being damaged. Therefore, the optical box 21 is moved to the main body frame 3 by repair or the like.
When the optical box 21 is detached from the optical box 21, it is sufficient only to loosen the exposed screws 33 fixing the optical box 21. If the exposed screws 30 fixing the cover 29 are loosened by mistake, the movement of the cover 29 does not affect the scanning position of the laser beam, so that there is no problem. Furthermore,
By loosening the screw 34, it is not necessary to return the positioning member 35 to the factory in order to readjust it, and it is possible to save time and labor required for transportation and work for that purpose. Then, it is possible to release mental fatigue and to perform an efficient work without calling out the worker or the repairer more than necessary.

FIG. 5 is a plan view of the second embodiment with the cover removed, and FIG. 6 is a side view with the cover attached. The optical box 51 is different from that of the first embodiment. Reference numeral 29 is the same as in the first embodiment. A screw insertion hole 53 and a positioning member 3 are provided in the flange 52 of the optical box 51.
A reference hole and a screw hole (not shown) for attaching the cover 5 and a reference pin 54 and a screw hole 55 for fixing the cover 29 are provided. The flange portion 51 is provided with vertical concealing portions 56 and 57 which extend substantially vertically from both sides of the positioning member 35 and conceal the screw 34. The vertical concealing portions 56 and 57 cooperate with the horizontal concealing portion 29b of the cover 29 to conceal the positioning member 35 in an arch shape.

The second embodiment is better than the first embodiment in that the screws 34 are loosened by the jig by the vertical concealing portions 56 and 57 of the optical box 51 and the horizontal concealing portion 29b of the cover 29. Can be prevented. Although the vertical concealing portions 56 and 57 are provided on the optical box 51, the cover 2
9 may be provided in the horizontal hiding part 29b.

FIG. 7 is a sectional view of a positioning member 61 according to the third embodiment. The positioning member 61 is formed of a synthetic resin material, and has the same main body 61a, reference pin 61b and screw insertion as in the first embodiment. In addition to the hole 61c, a small-diameter concave portion 61d and a large-diameter concave portion 61e are formed above the screw insertion hole 61c. The head 34a of the screw 34 is housed in the small-diameter concave portion 61d, and a sheet-like covering member 62 is disposed at the bottom of the large-diameter concave portion 61e so as to cover the opening of the small-diameter concave portion 61d, for example, by bonding or the like. Fixed.

In the third embodiment, since the screw 34 can be completely concealed by the covering member 62, the screw 34
Can be better prevented than in the above-described embodiment. Further, since it is not necessary to change the shapes of the conventional optical box and cover, it is possible to easily cope with the conventional one.

FIG. 8 is a sectional view of a positioning member 71 of the fourth embodiment. The positioning member 71 is made of synthetic resin.
A main body 71a, a reference pin 71b similar to those of the third embodiment,
Screw insertion hole 71c, small diameter recess 71d, large diameter recess 71
e, and a cover member 71f large enough to cover the opening of the small-diameter recess 71d is attached to the hinge 71.
They are formed integrally with each other via g. A locking projection 71h for locking the cover member 71f is formed in the opening of the large-diameter concave portion 71e.

In the fourth embodiment, the same effects as those of the third embodiment can be obtained.
Since f is integrally formed, the number of parts can be reduced, the labor for bonding can be omitted, and the cost can be reduced.

[0022]

As described above, since the deflecting device according to the present invention has the concealing means for concealing the positioning member, it is possible to prevent the fixing means from being loosened by mistake, and strict position adjustment of the positioning member can be performed. Damage can be prevented. Therefore, it is possible to save time and labor required for transportation and work for re-fixing the positioning member, and
It is possible to give the repairer a sense of security and to perform an efficient operation.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment with a cover removed.

FIG. 2 is a plan view showing a state where a cover is attached.

FIG. 3 is a side view showing a state where the camera is attached to a main body frame.

FIG. 4 is a partially exploded perspective view.

FIG. 5 is a plan view of the second embodiment with a cover removed.

FIG. 6 is a side view showing a state where a cover is attached.

FIG. 7 is a sectional view of a positioning member according to a third embodiment.

FIG. 8 is a sectional view of a positioning member according to a fourth embodiment.

FIG. 9 is a plan view of a conventional example.

FIG. 10 is a side view of a conventional example in a state of being attached to a main body frame.

[Explanation of symbols]

 21, 51 Optical box 22 Light source 24 Polygon mirror 25 Drive motor 26 Scanning lens 29 Cover 29b Horizontal concealing part 30, 33, 34 Screw 31 Body frame 32 Photoconductor drum 35, 61, 71 Positioning member 56, 57 Vertical concealing part 61d, 71d Small-diameter concave portion 61e, 71e Large-diameter concave portion 62, 71f Covering member 71h Locking portion

Claims (7)

[Claims] A light source for emitting a light beam; a polygon mirror for deflecting the light beam from the light source; a drive motor for rotating the polygon mirror; and a light beam from the polygon mirror for scanning a photosensitive member. A deflection scanning device in which a scanning lens and an optical box are attached to an optical box, the optical box has a positioning member having a cover and fixed by fixing means, and the optical box is positioned by the positioning member and assembled to an assembly. 3. The deflection scanning device according to claim 1, further comprising a concealing unit for concealing the positioning member. 2. The deflection scanning device according to claim 1, wherein the concealing means is a horizontal portion extending substantially horizontally above the positioning member from the cover. 3. The deflection scanning apparatus according to claim 2, further comprising a vertical portion extending substantially vertically from the optical box to both sides of the positioning member. 4. The deflection scanning device according to claim 1, wherein the concealing means is a covering member formed on the positioning member and covering an opening of a recessed part that houses the head of the fixing means so as not to protrude. 5. The deflection scanning device according to claim 4, wherein the cover member is capable of opening and closing the opening of the concave portion integrally with the positioning member. 6. The deflection scanning device according to claim 5, wherein the positioning member has a locking portion for locking the cover member at a closed position. 7. The deflection scanning device according to claim 1, wherein the positioning member is made of a synthetic resin.