JP4148559B2 - Lens positioning structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin lens positioning structure used in a laser beam generator.
[0002]
[Prior art]
A laser beam emitted from a beam generator attached in the laser beam generator is appropriately shaped by a lens attached in the laser beam generator, and is a photoconductor of an image forming unit via an optical polarizer or an optical system. Imaged above and scanned. The lens is positioned and attached with high accuracy to the beam generator emission side in the housing of the laser generator. The lens positioning structure will be described below.
[0003]
As shown in FIG. 3, reference numeral 10 denotes a lens for shaping a laser beam emitted from a beam generator (not shown). The lens 10 has a cube whose outer shape extends in the Z direction perpendicular to the horizontal direction with respect to the optical axis direction. Both end portions 10a of the lower surface of the lens 10 are positioning reference planes in the X direction (vertical direction) orthogonal to the optical axis direction and orthogonal to the Z direction. The reference plane 10a is a laser beam (not shown). The upper surface of the first reference base 11 integrally formed in the housing of the generator is in contact with the reference surface 11a. The reference surface 11a is a reference surface for positioning the lens 10 in the X direction. Accordingly, the lens 10 is positioned in the X direction by bringing the reference surface 10a into contact with the reference surface 11a.
[0004]
Reference projections 12 protruding in the Z direction are integrally formed on both side surfaces 10b in the longitudinal direction of the lens 10, respectively. One surface 12a of the reference projection 12 serves as a reference surface in the Y direction parallel to the optical axis direction. The reference surface 12a and the reference surface 13a of the second reference table 13 integrally formed in the housing are respectively provided. It comes to come in contact. The reference surface 13a is a reference surface for positioning the lens 10 in the Y direction. Accordingly, the lens 10 is positioned in the Y direction, that is, the optical axis direction by bringing the reference surface 12a into contact with the reference surface 13a.
[0005]
In addition, on one side surface (the back side surface in FIG. 3) of the four side surfaces of the lens 10 extending in the Z direction, a protruding portion 14 protruding in the direction orthogonal to the Z direction, that is, the Y direction is integrally formed. ing. The projecting portion 14 is adapted to engage with an engaging portion 15a of a reference plate 15 disposed in the housing. The engaging portion 15a of the reference plate 15 serves as a reference for positioning the lens 10 in the Z direction. Therefore, the lens 10 is positioned in the Z direction by engaging the protruding portion 14 with the engaging portion 15a.
[0006]
In this way, the lens 10 is positioned in the triaxial direction of the optical axis direction (Y direction) and the two directions (X direction and Z direction) orthogonal to the optical axis direction and orthogonal to each other. It is mounted with high precision in the housing.
[0007]
The beam generator is not always mounted parallel to the horizontal plane in the housing of the laser beam generator, but differs depending on the type of the apparatus. Accordingly, the optical axis direction of the laser beam emitted from the beam generator may or may not be parallel to the horizontal plane, and the above-mentioned inclination is the same as the inclination of the optical axis direction with respect to the horizontal plane. The lens 10 is positioned and mounted in the housing.
[0008]
When the optical axis direction is an angle α (> 0) in the plus direction with respect to the horizontal plane, the lens 10 is tilted to the angle α and is mounted in the housing. Specifically, as shown in FIG. 4, the reference surface 11a of the first reference table 11 is formed to be inclined at an angle α, and the reference surface 10a of the lens 10 is in contact with the reference surface 11a. Further, the reference surface 13a of the second reference table 13 is formed so as to be orthogonal to the reference surface 11a formed to be inclined at an angle α, and one surface 12a of the reference protrusion 12 integrally formed with the lens 10 on the reference surface 13a. Is faced. Therefore, the lens 10 is positioned so as to have the same inclination as the inclination with respect to the horizontal plane in the optical axis direction, and is mounted in the housing in an upward posture.
[0009]
When the optical axis direction is an angle β (<0) in the minus direction with respect to the horizontal plane, the lens 10 is positioned at an angle β and mounted in the housing. More specifically, as shown in FIG. 5, the reference surface 11a of the first reference table 11 is formed to be inclined at an angle β, and the reference surface 10a of the lens 10 is in contact with the reference surface 11a. Further, the reference surface 13a of the second reference table 13 is formed so as to be orthogonal to the reference surface 11a formed to be inclined at an angle β, and one surface 12a of the reference protrusion 12 formed integrally with the lens 10 on the reference surface 13a. Is faced. Accordingly, the lens 10 is positioned so as to have the same inclination as the inclination with respect to the horizontal plane in the optical axis direction, and is mounted in the housing in a downward posture.
[0010]
[Problems to be solved by the invention]
As described above, the first reference base 11 and the second reference base 13 are integrally formed in a housing, and the housing can be die-cast or plastic-molded by a mold. As shown in FIG. 4, when the reference surface 11a of the first reference table 11 is inclined at an angle α (> 0), the top of the second reference table 13 on which the reference surface 13a is formed is formed. Since the metal mold is not caught, the metal mold can be extracted upward from the molded housing.
[0011]
However, as shown in FIG. 5, when the reference surface 11a of the first reference base 11 is formed to be inclined at an angle β (<0), the molded housing is to be extracted upward from the mold. Since the portion where the reference surface 13a of the second reference base 13 is formed is hook-like, the hook-like portion where the reference surface 13a of the second reference base 13 is formed is caught by the mold. Accordingly, in this case, the mold for forming the bottom surface side of the housing is formed with a protruding portion that partially protrudes into a shape corresponding to the bowl-shaped portion on which the reference surface 13a of the second reference table 13 is formed. Therefore, the cost of manufacturing the mold is increased. In FIG. 5, the hole 9 formed in the housing is formed by a protrusion formed in the mold in order to mold the bowl-shaped part.
[0012]
Such a problem is that the reference surface 12a of the reference projection 12 of the lens 10 serving as a reference surface for positioning in the optical axis direction is a plane perpendicular to the reference surface 10a in the X direction orthogonal to the optical axis direction. This is because the reference surface 13a of the second reference table 13 is formed so as to be in contact with the reference surface 12a formed on this plane.
[0013]
The present invention has been made to solve the above-described problems of the prior art, and by making the reference surface for positioning in the optical axis direction on the lens side an arc surface, the housing can be easily mounted on the mold. It is an object of the present invention to provide a lens positioning structure that can be formed into a shape that can be extracted and that can be manufactured at low cost without forming the mold in a partially protruding shape.
[0014]
[Means for Solving the Problems]
The invention according to claim 1 is a resin lens positioning structure used for a laser beam generator for shaping a laser beam emitted from a beam generator, wherein the resin lens is in the optical axis direction. Protrusions that extend in a direction perpendicular to each other and have arc surfaces that serve as a reference in the optical axis direction project from both side surfaces in the length direction of the resin lens in the length direction of the resin lens. A reference surface with which the projection of the resin lens abuts is formed in a direction perpendicular to the bottom surface of the housing and serves as a positioning reference in a direction perpendicular to the optical axis of the resin lens. The surface is formed to be inclined with respect to the bottom surface of the housing .
[0015]
According to a second aspect of the present invention, in the first aspect of the present invention, the arc surface is a cylindrical arc surface.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a lens positioning structure according to the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a resin lens for shaping a laser beam emitted from a beam generator (not shown) mounted in a housing of the laser generator into a predetermined cross-sectional shape. . The beam generator is inclined with respect to a horizontal plane and mounted in the housing in a downward posture. Therefore, the optical axis direction of the laser beam emitted from this beam generator is at an angle β (<0) with respect to the horizontal plane as shown in FIG. The resin lens 1 is positioned and attached with high accuracy to the beam generator emission side in the housing of the laser generator.
[0017]
The positioning structure of the resin lens 1 will be specifically described. As shown in FIGS. 1 and 2, the resin lens 1 is formed in a cubic shape whose outer shape extends in the Z direction perpendicular to the horizontal direction with respect to the optical axis direction. Both ends 1a of the lower surface of the resin lens 1 are orthogonal to the optical axis direction and serve as reference surfaces in the X direction (vertical direction in FIG. 1) perpendicular to the Z direction. It comes into contact with the reference surface 21a of the first reference table 21 formed integrally in the housing of the beam generator.
[0018]
The reference surface 21a of the first reference table 21 is a reference surface for positioning the lens 1 in the X direction, and is formed to be inclined at the angle β. Therefore, the resin lens 1 is positioned in the X direction by bringing the reference surface 1a into contact with the reference surface 21a.
[0019]
On both side surfaces 1b in the length direction of the resin lens 1, protrusions 22 having an outer shape protruding in the Z direction are integrally formed. An arc surface 22a that is an outer peripheral surface of the protrusion 22 serves as a reference surface in the optical axis direction, that is, the Y direction, and the arc surface 22a is a reference surface of the second reference base 23 that is integrally formed in the housing. 23a is in contact with each other.
[0020]
The reference surface 23 a of the second reference table 23 is a reference surface for positioning the resin lens 1 in the optical axis direction (Y direction). Accordingly, the resin lens 1 is positioned in the optical axis direction by bringing the arc surface 22a into contact with the reference surface 23a. As shown in FIG. 2, the reference surface 23a of the second reference table 23 is formed perpendicular to the bottom surface of the housing. Therefore, the reference surface of the first reference table 21 formed at an angle β is formed. It is not orthogonal to 21a.
[0021]
Further, as shown in FIG. 1, one of the four side surfaces (the back side surface in FIG. 1) of the resin lens 1 extending in the Z direction has a direction orthogonal to the Z direction, that is, the optical axis direction. A projecting portion 24 projecting into the shape is integrally formed. The protruding portion 24 is adapted to engage with an engaging portion 25a of a reference plate 25 disposed in the housing. The engaging portion 25a of the reference plate 25 serves as a reference for positioning the resin lens 1 in the Z direction. Therefore, the resin lens 1 is positioned in the Z direction by bringing the protruding portion 24 into contact with the engaging portion 25a in a point contact manner.
[0022]
As described above, the resin lens 1 is positioned in the triaxial direction of the optical axis direction (Y direction) and two directions (X direction and Z direction) orthogonal to the optical axis direction and orthogonal to each other. It is attached with high accuracy to the beam generator emission side in the housing of the laser generator.
[0023]
As described in the section of the problem to be solved by the invention, in the conventional positioning structure, the reference surface 12a of the reference protrusion 12 of the lens 10 serving as the reference surface for positioning in the optical axis direction is in the optical axis direction. The reference surface 13a of the second reference base 13 is formed so as to be in a plane perpendicular to the reference surface 10a in the orthogonal X direction and to be in contact with the reference surface 12a formed on this plane. Therefore, when the optical axis direction is at an angle β (<0) with respect to the horizontal plane as shown in FIG. 5, the portion where the reference surface 13a of the second reference base 13 is formed is And a portion corresponding to the bowl-shaped portion where the reference surface 13a of the second reference table 13 is formed on one of the molds for molding the housing. Because it has to form a There has been a problem that the cost of manufacturing the mold becomes high.
[0024]
On the other hand, in the above embodiment, since the reference surface of the resin lens 1 that contacts the reference surface 23a for positioning the resin lens 1 in the optical axis direction is formed on the arc surface 22a, the reference surface 23a is The resin lens 1 can be positioned in the optical axis direction without being formed perpendicular to the reference surface 21a of the first reference table 21 formed to be inclined at the angle β.
[0025]
Therefore, when the optical axis direction is the angle β (<0) with respect to the horizontal plane, the portion of the second reference base 23 where the reference surface 23a is formed is bowl-shaped so as to have an angle β with respect to the horizontal plane. It is not necessary to project, and the housing mold can be easily extracted from above with respect to the mold. Moreover, since it is not necessary to make a metal mold | die project partially, a metal mold | die can be manufactured at low cost.
[0026]
In the above-described embodiment, the arc surface 22a is the outer peripheral surface of the cylinder 22, but is not limited thereto, and may be a semi-arc surface of a half-moon-shaped tube, a hemispherical outer peripheral surface, or the like. In short, it is only necessary that the portion in contact with the reference surface 23a in the optical axis direction is formed as an arc surface. Moreover, in the said embodiment, although the external shape of the said resin-made lens 1 is a cube extended in the Z direction orthogonal to an optical axis direction, it is not restricted to this, What can shape a laser beam suitably Any shape can be used.
[0027]
Moreover, although the said embodiment demonstrated the case where the optical axis direction of a laser beam was an angle (beta) (<0) with respect to a horizontal surface, the reference | standard which positions the resin-made lens 1 in the optical axis direction Since the reference surface of the resin lens 1 in contact with the surface 23a is formed on the circular arc surface 22a, the above object can be achieved regardless of the angle of the optical axis direction of the laser beam with respect to the horizontal plane. Can do. Further, the reference surface 23a is not necessarily perpendicular to the bottom surface of the housing, and may be formed to be inclined as in the example shown in FIG.
[0028]
【The invention's effect】
The invention according to claim 1 is a resin lens positioning structure used for a laser beam generator for shaping a laser beam emitted from a beam generator, wherein the resin lens is in the optical axis direction. Protrusions that extend in a direction perpendicular to each other and have arc surfaces that serve as a reference in the optical axis direction project from both side surfaces in the length direction of the resin lens in the length direction of the resin lens. A reference surface with which the projection of the resin lens abuts is formed in a direction perpendicular to the bottom surface of the housing and serves as a positioning reference in a direction perpendicular to the optical axis of the resin lens. since the surface is formed to be inclined with respect to the bottom surface of the housing, regardless of the mounting orientation of the lens, the shape of the reference surface of the housing, easy to disconnect the mold from the reference plane It is possible to shape can take, it is not necessary to the shape of the mold was partially protrude, it is possible to manufacture a mold at a low cost.
[0029]
The invention according to claim 2 is the invention according to claim 1, wherein the arc surface is a cylindrical arc surface, so that the shape of the reference surface of the housing is the same regardless of the lens mounting orientation. Thus, the mold can be easily extracted, and it is not necessary to make the mold partially protruded. Therefore, the mold can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an embodiment of a lens positioning structure according to the present invention.
FIG. 2 is a side view showing the embodiment.
FIG. 3 is an exploded perspective view showing an example of a conventional lens positioning structure.
FIG. 4 is a side view showing the conventional lens positioning structure.
FIG. 5 is a side view showing another example of a conventional lens positioning structure.
[Explanation of symbols]
1 Resin Lens 1a Reference Surface 21 First Reference Table 21
21a Reference surface 22a Arc surface 23 Second reference table 23a Reference surface

Claims (2)

A resin lens positioning structure for shaping a laser beam emitted from a beam generator used in a laser beam generator,
The resin lens extends in a direction perpendicular to the optical axis direction,
Protrusions having an arc surface serving as a reference in the optical axis direction protrude in the length direction of the resin lens from both side surfaces in the length direction of the resin lens,
On the housing side to which the resin lens is attached, a reference surface with which the arc surface of the protrusion of the resin lens abuts is formed in a direction perpendicular to the bottom surface of the housing and orthogonal to the optical axis of the resin lens. A lens positioning structure characterized in that a surface serving as a positioning reference in a direction to be inclined is formed with respect to the bottom surface of the housing .   The lens positioning structure according to claim 1, wherein the arc surface is a cylindrical arc surface.

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