JPH1195147A - Scanning optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning optical device which facilitates attaching and detaching work by making it possible to assemble a reflection mirror used for reflecting the laser beam deflected by a rotary polyhedral mirror to a prescribed direction of the scanning optical device consisting of a laser optical system and to attach and detach the reflection mirror to and from the outside of a casing for supporting the reflection mirror without complicating and enlarging the internal structure of the casing and the internal structure of the other casing. SOLUTION: A hole 41 is formed at the proper point of the wall part 40 of the casing 10 of the scanning optical device equipped with the light source, the rotary polyhedral mirror 15, the imaging optical parts and at least one sheet of the reflection mirror 17, the casing to equip these members and a cover 21 for closing the opening of the casing 10. The reflection mirror 17 is mounted at the outer flank of the wall part 40 of the casing so as to close the hole 41 and to expose the reflection surface from the hole 41. The outer flank of the wall part of the casing is provided with a projecting part for supporting only part of the peripheral edge on the reflection surface side of the reflection mirror 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a scanning optical device as an optical writing means used in an image forming apparatus such as a printer, a facsimile, a copying machine or the like using an electrophotographic system, and more particularly to an optical component such as a reflection mirror. The present invention relates to a scanning optical device that enables a reflection mirror to be attached to and detached from a housing in which a positioning is stored.

[0002]

2. Description of the Related Art A scanning optical apparatus using a laser is used in various electrophotographic image forming apparatuses. Fig. 3 (a)
(b) is a schematic diagram of a conventional scanning optical device. The scanning optical device 1 is a known laser optical system. Laser light emitted from a light source 11 passes through a collimator lens 12, an aperture 13, and a cylinder lens 14, and is a polygon mirror attached to a motor that rotates in the direction of an arrow. The light is deflected by 15, passes through an imaging lens 16, is deflected in a desired direction by a reflecting mirror 17, passes through a dust-proof glass 18 provided to prevent intrusion of dust and the like, and reaches the surface of the photoconductor 2. . These optical components are the resin casing 10 shown in FIG.
The housing opening is hermetically sealed by a cover 21 that is housed in the housing and similarly prevents invasion of dust and the like. Code 19
Is a synchronization detection device 19, and a control unit (not shown) controls writing based on data on laser light obtained from the synchronization detection device 19.

[0003]

Problems to be Solved by the Invention Japanese Patent Application Laid-Open No. 9-73038
Japanese Patent Application Laid-Open No. 9-73039 and Japanese Patent Application Laid-Open No. 9-73039 disclose a structure in which the reflecting mirror 17 is supported by a wall or a support member inside a housing. As shown in FIGS. 4 (a) and (b), the inclined surface 3 of the support projection 30 protruding from the inner bottom surface of the housing 10 at a predetermined interval.
1, the back surface of the reflecting mirror 17 is supported, and the other surface of the reflecting mirror 17 is pressed in place by the other end of the leaf spring 33 having one end fixed to the inner bottom surface of the housing by a bolt 32 or the like. In all of the conventional examples, it is necessary to dispose the reflecting mirror 17 inside the housing 10 and open the cover 21 when attaching or detaching the reflecting mirror. The reflecting mirror is used to reflect light in a desired direction, but depending on the direction of reflection, the internal structure of the housing for supporting the reflecting mirror becomes complicated, and the relationship with other parts and the like is increased. As a result, the internal structure of the housing becomes complicated, which may cause problems such as an increase in manufacturing cost and an increase in size. To avoid complication of the internal structure of the housing itself,
There is a problem that adding another part further increases the cost. The present invention has been made in view of the above, and in a scanning optical device including a laser optical system,
Assembling the reflector inside the housing to support the reflector used to reflect the laser beam deflected by the rotating polygon mirror in a predetermined direction, and other complicated internal structures without increasing the size of the housing It is an object of the present invention to provide a scanning optical device which enables the reflection mirror to be detachable from the outside of the housing, thereby facilitating the attachment / detachment operation.

[0004]

In order to achieve the above object, the invention of claim 1 comprises a light source, a rotating polygon mirror, an imaging optical component,
In a scanning optical device including at least one reflecting mirror, a housing provided with the reflecting mirror, and a cover for closing an opening of the housing, a hole is formed at an appropriate position on a wall of the housing, and the hole is formed. A reflecting mirror is attached to the outer surface of the housing wall so as to cover and expose the reflecting surface from the hole. The invention according to claim 2 is characterized in that a projection for supporting only a part of the peripheral edge of the reflection mirror on the reflection surface side is provided on the outer surface of the housing wall.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. 1 (a), 1 (b) and 1 (c) are an overall longitudinal sectional view, a perspective view of a reflecting mirror, and a perspective view of a main part of a scanning optical device according to an embodiment of the present invention, and also refer to FIG. The same parts will be described with the same reference numerals. The laser light deflected by the rotary polygon mirror 15 and passed through the imaging lens 16 is reflected by the reflecting mirror 17 in a predetermined direction (upward in this example). Holes 41 are previously formed in the housing wall portion 40 where the
Is formed, and the reflecting mirror 17 is fixed from the back side (outside) of the housing wall portion 40 so that the reflecting mirror 17
Is characterized in that the reflective surface is exposed. In this example, the opening diameter and the opening shape of the hole 41 are set to a shape corresponding to the inner reflecting surface of the reflecting surface of the reflecting mirror 17 (the contact portion in FIG. 1B). The contact portion located is brought into contact with the outer surface of the housing wall portion 40 (peripheral portion of the hole 41) and is fixed. As a result, a structure in which the reflecting surface of the reflecting mirror is exposed from the hole 41 is obtained. As the fixing method, an adhesive, FIG.
Various means such as a leaf spring and a screw shown in FIG. The housing wall portion 40 is located on the bottom surface of a recess 45 in which an appropriate portion of the outer surface of the housing is dented as shown in the figure. By setting the shape to match the external shape, the positioning of the reflecting mirror becomes easier. In the present embodiment, since the reflecting mirror can be attached and detached from the outside of the housing, the work becomes easy. Further, since the mounting surface of the reflecting mirror is provided on the outer surface of the housing, the structure inside the housing can be prevented from becoming complicated. In addition, when the reflecting mirror is fixed to the entire inner surface of the housing inside the housing as in the conventional case, it is necessary to ensure the flatness of the back surface of the reflecting mirror accurately, which increases the processing cost of the reflecting mirror and increases the reflection cost. Although the mounting accuracy of the mirror is deteriorated, such a problem does not occur if only a part of the reflecting surface side of the reflecting mirror is brought into contact with and supported by the housing wall as in this embodiment. .

FIGS. 2 (a), 2 (b), 2 (c), 2 (d) and 2 (e) are longitudinal sectional views of a main part of a scanning optical apparatus according to another embodiment of the present invention, and FIG. It is a principal part perspective cutaway view, a principal part perspective view, and a principal part perspective sectional view. The feature of this embodiment is that the reflector 41 is provided at appropriate positions along the periphery of the hole 41 (outer surface of the housing wall portion 40) and at both ends in the longitudinal direction (or both ends in the transverse direction) of the reflecting mirror 17 in the embodiment of FIG. The point is that a projection 50 for contacting and supporting this is provided to partially support the reflecting mirror 17. Instead of supporting the entire periphery on the reflecting surface side of the reflecting mirror in this way,
The reason for supporting a part is that if the entire peripheral edge on the reflecting surface side is supported by the wall portion 40 as shown in FIG. 1, it is necessary to perform processing for ensuring the flatness of the contact portion of the reflecting mirror over the entirety. This leads to an increase in manufacturing cost and the like. The above problem is solved by providing a projection 50 having a minimum necessary contact area in order to minimize the contact area between the wall portion 40 and the reflecting mirror in FIG. It is a form example.

As a method of supporting the reflecting mirror 17 on the contact portion (receiving surface) of the projection 50, an adhesive, a leaf spring, a screw, or the like can be selected. The gap formed between the outer surface of the housing wall 40 and the reflecting mirror 17 may be sealed using a sealing means (not shown). Also in this embodiment, the housing wall portion 40 is located on the bottom surface of the recess 45 in which the housing outer surface is depressed as shown in the figure. By setting the shape and dimensions of the reflector to a shape that matches the outer shape of the reflecting mirror 17 in advance, the positioning of the reflecting mirror becomes easier. Also in this embodiment, since the reflecting mirror can be attached and detached from the outside of the housing, the operation becomes easy. Further, since the mounting surface of the reflecting mirror is provided on the outer surface of the housing, the structure inside the housing can be prevented from becoming complicated. In addition, when the reflecting mirror is fixed to the entire inner surface of the housing inside the housing as in the conventional case, it is necessary to ensure the flatness of the back surface of the reflecting mirror accurately, which increases the processing cost of the reflecting mirror and increases the reflection cost. Although the mounting accuracy of the mirror is deteriorated, if the structure is such that only a part of the reflecting surface side of the reflecting mirror is brought into contact with the housing wall portion and supported as in this embodiment,
Such a defect does not occur. Further, since the contact area between the housing and the reflecting mirror is smaller than in the case of FIG.
Even if the processing accuracy on the housing side is low, the cost can be reduced and the productivity can be improved. Also, when light is reflected upward by the reflecting mirror 17 as in the embodiment shown in FIGS. 1 and 2, it is particularly easy to assemble when the reflecting mirror 17 is attached from the outside of the housing 10 as shown in the figure. Becomes

[0008]

As described above, in the scanning optical device of the first aspect, the reflecting mirror is attached from the outside of the housing so as to cover the hole provided in the housing, so that the assembly is easy. In addition, since the reflecting mirror is a part of the wall of the housing, no cover is required. Further, since there is no need to provide a projection, a structure, and the like for disposing the reflecting mirror inside the housing, the configuration is simplified. In the scanning optical device according to the second aspect, since the height of the portion other than the receiving surface of the protrusion is set to a height escaping from the receiving surface,
The housing can be easily formed. Further, since the contact area between the reflecting mirror and the housing can be reduced, the degree of processing accuracy (flatness) of the reflecting mirror can be reduced, so that cost reduction and productivity improvement can be achieved.

[Brief description of the drawings]

1A, 1B, and 1C are an overall sectional view of a scanning optical device according to an embodiment of the present invention, a perspective view of a reflecting mirror, and a perspective view of a main part.

2 (a), (b), (c), (d), and (e) are cross-sectional views of main parts of a scanning optical device according to another embodiment of the present invention, and are AA cross-sectional view and main part perspective views thereof. It is a principal part perspective view, and a principal part perspective sectional view.

FIGS. 3A and 3B are explanatory diagrams of a configuration of a conventional scanning optical device.

4 (a) and 4 (b) are explanatory diagrams of a conventional example.

[Explanation of symbols]

1 scanning optical device, 11 light source, 12 collimating lens, 13 aperture, 14 cylinder lens, 15
Polyhedral mirror, 16 imaging lens, 17 reflecting mirror, 18 dust-proof glass, 21 cover, 40 housing wall, 41 hole, 50
Protrusion.

Claims (2)

[Claims] 1. A scanning optical device comprising a light source, a rotating polygon mirror, an imaging optical component, at least one reflecting mirror, a housing equipped with them, and a cover closing an opening of the housing. A scanning optical device, wherein a hole is formed at an appropriate position on the wall of the housing, and a reflecting mirror is attached to an outer surface of the housing wall so as to close the hole and expose a reflecting surface from the hole. . 2. The scanning optical device according to claim 1, wherein a projection for supporting only a part of the peripheral edge of the reflection mirror on the reflection surface side is provided on the outer surface of the housing wall.