JPH1039242A - Scanning optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the assemblage of a turn back mirror. SOLUTION: The turn back mirror 5 turning back the scanning light L1 of a rotary polygon mirror 3 toward a rotary drum 6 is built into the mirror supporting body 10 of an optical box 7 with a spring 11 being integrated to a lid member 9. The return back mirror 5 is carried in the optical box 7 by being temporarily held in a mirror holder 12 being integrated to the lid member 9 and the lid member 9 is screwingly fixed to the optical box 7 in a state in which the turn back mirror 5 is pressurized with the spring 11.

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 used for an image forming apparatus such as a laser printer and a laser facsimile.

[0002]

2. Description of the Related Art As shown in FIG. 6, a scanning optical device used in an image forming apparatus such as a laser printer or a laser facsimile is configured to linearly scan a laser beam generated from a light source unit 101 having a semiconductor laser 101a by a cylindrical lens 102. Condensed into a luminous flux, and the rotating polygon mirror 103
Direction along the axis of rotation (hereinafter, "Z-axis direction")
That. ), A deflection scan is performed in a predetermined direction (hereinafter, referred to as a “Y-axis direction”), and an image forming lens system 104 including a spherical lens 104a and a toric lens 104b, and a turning mirror 105 (see FIG. 7). ) Form an image on the upper photoconductor. The light beam formed on the photoreceptor forms an electrostatic latent image by the main scanning in the Y-axis direction by the rotation of the rotary polygon mirror 103 and the sub-scanning in the Z-axis direction by the rotation of the rotary drum D.

The scanning light L ₀ from the rotary polygon mirror 103 is separated by a BD mirror 106 a below the scanning surface at one end of the scanning surface (XY plane) in the Y-axis direction, introduced into a BD sensor 106 b, and starts scanning. The light is converted into a signal and transmitted to the semiconductor laser 101a of the light source unit 101. The semiconductor laser 101a starts the write modulation after receiving the scanning start signal.

A light source unit 101, a cylindrical lens 102, a rotating polygon mirror 103, an imaging lens system 104, B
The D mirror 106a, the BD sensor 106b, and the like are attached to the side wall 107a and the bottom wall 107b of the optical box 107. The rotating drum D is disposed below the optical box 107, and a folding mirror 1 is provided on the bottom wall 107b of the optical box 107.
There is provided a window 108 for taking out the scanning light L ₀ reflected by 05 from the optical box 107 toward the rotating drum D.

The folding mirror 105 is a rod-shaped member elongated in the Y-axis direction.
It is supported by a pair of mirror supports 109 projecting inward from 7a. To assemble the folding mirror 105, the both ends thereof are placed on the mirror support 109, and the leaf spring 1
10 elastically press down and fix. As shown in FIG. 8, each leaf spring 110 is a plate-like body having contact portions 110a and 110b contacting the rear surface and the end surface of the folding mirror 105. Locked. Alternatively, there is a configuration in which both ends of the folding mirror 105 are directly bonded to each mirror support 109.

The upper opening of the optical box 107 is
And then closed by the lid member 111.

[0007]

However, according to the above-mentioned prior art, as described above, the folding mirror is supported on the mirror support of the optical box and bonded or fixed with a leaf spring to fix the optical box. Since it is configured to attach the lid member after assembling all necessary parts,
The bonding process is complicated, hindering the simplification and automation of the assembling process, increasing the number of assembly parts due to the leaf spring, and increasing the number of assembly steps due to the process of assembling the leaf spring to the optical box. There is a problem to be solved.

In addition, when it is necessary to repair or replace the folding mirror of the scanning optical device after the assembly is completed, a complicated operation such as removing the lid member and then removing the leaf spring or the like is required. I need. If the folding mirror is adhered to the mirror support, the folding mirror must be forcibly peeled off, and even if a leaf spring is used, if the leaf spring is securely attached, the folding mirror will not be removed. It may be damaged.

[0009] Since the folding mirror cannot be easily removed once assembled, it is difficult to repair or replace the folding mirror. Further, in the rear of the reflecting mirror, when the opening M ₀ for monitor for examining beam diameters Remove the scanning light L ₀ from the optical box is provided, when it is impossible to remove the folding mirror easily Also, it becomes difficult to check the beam diameter after the assembly of the apparatus is completed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the related art, and provides an inexpensive scanning optical apparatus in which the folding mirror can be easily assembled to the optical box and the number of parts of the apparatus can be reduced. It is intended to provide.

[0011]

In order to achieve the above object, a scanning optical device according to the present invention comprises at least one folding mirror provided in an optical path of scanning light of a rotary polygon mirror, and a supporting mirror for the folding mirror. An optical box having a mirror support, a lid member for closing the opening of the optical box, and an elastic member provided integrally with the lid member, wherein the elastic member is
When the lid member is attached to the optical box, it is configured to engage with the folding mirror and press it against the mirror support.

The elastic member may be formed integrally with the lid member.

[0013] An elastic member may be welded to the lid member.

It is preferable that the lid member includes a mirror holding means for temporarily holding the folding mirror before being assembled to the optical box.

[0015]

Since the elastic member for assembling the return mirror to the optical box is integral with the lid member of the optical box, the assembly of the return mirror can be completed in the step of attaching the lid member to the optical box. Compared to the case where the elastic member is assembled to the optical box and the folding mirror is assembled, and finally the lid member is attached to the optical box, the number of assembly steps of the device is greatly reduced and the number of assembly parts is reduced, The manufacturing cost of the scanning optical device can be greatly reduced.

Further, when the lid member is removed from the optical box, the pressing force of the elastic member together with the lid member is released, so that it is extremely easy to repair or replace the folding mirror after the assembly of the device is completed. .

If the lid member is made of resin, the number of assembled parts can be further reduced by using an elastic member integrally formed with the lid member.

Further, if the lid member is provided with mirror holding means for temporarily holding the folding mirror before being assembled to the optical box, the step of carrying the folding mirror into the optical box before closing the lid member is omitted. By omitting, the number of assembly steps of the apparatus can be further reduced.

[0019]

FIG. 1 is a schematic sectional view showing a scanning optical device according to one embodiment. Laser light generated from a light source unit (not shown) having a semiconductor laser is condensed into a linear light beam by a cylindrical lens, and is deflected and scanned by a rotary polygon mirror 3 in a predetermined scanning direction perpendicular to its rotation axis. An image is formed on the photoconductor on the rotating drum 6 via the mirror 4 and the folding mirror 5. The light beam that forms an image on the photoreceptor forms an electrostatic latent image by main scanning by rotating the rotating polygon mirror 3 and sub-scanning by rotating the rotating drum 6.

The scanning light L ₁ of the rotary polygon mirror 3, which reaches one end of the scanning surface, is introduced into a BD sensor (not shown), converted into a scanning start signal, and transmitted to the semiconductor laser of the light source unit. The semiconductor laser starts writing modulation after receiving the scanning start signal.

The light source unit, the cylindrical lens, the rotary polygon mirror 3, the imaging lens 4, the folding mirror 5, and the like are mounted on the side wall 7a and the bottom wall 7b of the optical box 7. The rotating drum 6 is disposed below the optical box 7, and the bottom wall 7 b of the optical box 7 extracts the scanning light L ₁ reflected by the folding mirror 5 from the optical box 7 toward the rotating drum 6. Windows 8 are provided. The upper opening of the optical box 7 is closed by the lid member 9.

On the side wall 7a of the optical box 7, a pair of mirror supports 10 for supporting both ends of the folding mirror 5, which is a long rod, are provided.
Is elastically pressed and fixed to the mirror support 10 by a pair of springs 11 which are elastic members provided integrally with the lid member 9. The lid member 9 is made of resin, and the two springs 11 are integrally formed with the lid member 9 together with a pair of mirror holders 12 which are mirror holding means provided outside thereof.

As shown in FIG. 2, each mirror holder 12 has a pair of arms 12a for supporting the folding mirror 5 from the side of the reflection surface (lower surface) 5a when the folding mirror 5 is assembled.
A pair of abutting members 13 that are in contact with both end surfaces of the folding mirror 5 to position the folding mirror 5 are provided outside the mirror holders 12. It is integrally molded with.

The work of assembling the folding mirror 5 with respect to the optical box 7 is performed in a step of mounting necessary parts in the optical box 7 and then attaching the lid member 9. First, FIG.
As shown in (1), the folding mirror 5 is held downward by each mirror holder 12 of the lid member 9, and both ends thereof are brought into contact with the contact member 13 for positioning. In the step of covering the upper opening of the optical box 7 with the lid member 9 as shown by the arrow A in FIG. 2, the folding mirror 5 is lowered together with the lid member 9 and carried into the optical box 7 as shown in FIG. The reflection surface side of the folding mirror 5 is brought into contact with and supported by both mirror supports 10 of the optical box 7.

Subsequently, the lid member 9 is lowered, and the peripheral portion of the lid member 9 is moved to the side wall 7a of the optical box 7 as shown in FIG.
When the spring 11 is brought into contact with the upper end of the
The mirror 12 is elastically deformed by being brought into contact with the rear surface 5b of the mirror holder 12 and the arm 12a of each mirror holder 12 is separated from the folding mirror 5 and suspended thereunder. Is pressed.

If the lid member 9 is screwed to the optical box 7 in this state, the folding mirror 5 is also elastically fixed to each mirror support 10. In other words, the folding mirror 5 can be assembled at the same time only by attaching the lid member 9 to the optical box 7.

When removing the lid member 9 from the optical box 7, the springs 11 and the mirror holders 12 are raised together with the lid member 9 being raised. As a result, the pressing force of each spring 11 is released, and each mirror holder 12
From each mirror support 10. That is, simply by removing the lid member 9, the return mirror 5 is automatically removed.

In this embodiment, since the spring for assembling the return mirror to the optical box and the mirror holder and the like used for the assembling work are integrally formed with the lid member, the spring and the like for assembling the return mirror are individually provided. The number of assembly parts can be reduced as compared with the case of manufacturing and using. Further, since the folding mirror is automatically assembled during the operation of attaching the lid member, the assembling process is simple and easy to automate, and the number of assembling processes can be greatly reduced. Thereby, the cost reduction of the scanning optical device can be greatly promoted.

Further, the folding mirror is automatically removed at the same time when the lid member is removed, and the pressing force is released without difficulty simply by raising the spring that has pressed the folding mirror. There is no trouble such as damage to the return mirror in the process of removing the mirror. Since the folding mirror can be easily removed in this way, maintenance such as repair and replacement of the folding mirror is extremely easy, and rescanning is performed using the monitor opening of the optical box provided behind the folding mirror. The work of measuring the beam diameter of light is also simple. In addition, there is a remarkable advantage that the reflection surface of the folding mirror can be completely cleaned from end to end by removing the folding mirror from the lid member.

In this embodiment, the lid member and the spring are integrally formed of resin. However, even if a highly elastic sheet metal spring is manufactured separately and this is thermally welded to the resin lid member. Good. Although the number of assembled parts will increase,
This is the same in that the folding mirror can be assembled simultaneously with the attachment of the lid member.

FIG. 5 shows a plurality of folding mirrors 25a and 25.
b, the lid member 29 separates the folding mirrors 25a and 25b individually from the mirror support members 20a and 20b.
Springs 21a and 21b for pressing the mirrors 20b and mirror holders 22 for individually holding the mirrors 25a and 25b
a and 22b. The springs 21a and 21b and the mirror holders 22a and 22b are all integrally formed with the lid member 29. Each mirror holder 22 of the lid member 29
a, 22b hold the folding mirrors 25a, 25b, cover the optical member 7 with screws, and fix the lid member 29 to the optical box 7.
a and 25b are assembled at the same time.

As described above, even if there are a plurality of folding mirrors,
Since the assembling operation is completed at once by attaching the lid member, there is an advantage that the number of assembly steps can be greatly reduced as the number of folding mirrors increases.

[0033]

Since the present invention is configured as described above, the following effects can be obtained.

The assembling of the folding mirror with respect to the optical box is simple, the number of assembly parts is small, and the work of removing the folding mirror after the assembly of the apparatus is completed is extremely simple.

As a result, it is possible to realize a scanning optical device whose manufacturing cost is low and maintenance is easy. By using such a scanning optical device, it is possible to greatly contribute to cost reduction and running cost reduction of the image forming apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a scanning optical device according to one embodiment.

FIGS. 2A and 2B show the scanning optical device of FIG. 1 in a state before a lid member is assembled, and FIG.
(B) is a partial sectional view in the optical axis direction.

FIG. 3 is a partial sectional view showing a step of assembling a lid member of FIG. 2;

FIG. 4 is a partial sectional view showing a state where the lid member of FIG. 2 is assembled.

FIG. 5 is a partial sectional view showing a main part of a modification.

FIG. 6 is a schematic plan view showing one conventional example.

FIG. 7 is a schematic sectional view of the apparatus of FIG.

8 is a partially enlarged cross-sectional view showing a main part of the device of FIG. 6 in an enlarged manner.

[Explanation of symbols]

 Reference Signs List 3 rotating polygon mirror 4 imaging lens 5, 25a, 25b folding mirror 6 rotating drum 7 optical box 8 window 9, 29 lid member 11, 21a, 21b spring 12, 22a, 22b mirror holder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication B41J 2/455

Claims (5)

[Claims] 1. An optical box having at least one folding mirror disposed in an optical path of scanning light of a rotary polygon mirror, a mirror support for supporting the folding mirror, and closing an opening of the optical box. A lid member, and an elastic member provided integrally with the lid member, the elastic member engaging with the folding mirror when the lid member is attached to the optical box and supporting the mirror with the mirror. A scanning optical device configured to press against a body. 2. The scanning optical device according to claim 1, wherein the elastic member is formed integrally with the lid member. 3. The scanning optical device according to claim 1, wherein the elastic member is welded to the lid member. 4. The scanning optical device according to claim 1, wherein the lid member is made of a resin. 5. The scanning optical device according to claim 1, wherein the lid member includes a mirror holding unit for temporarily holding a folding mirror before being assembled to the optical box.