JPH02157807A - Lens fitting mechanism - Google Patents

Abstract

PURPOSE:To reduce the number of components, to facilitate positioning regulation and to miniaturize the whole structure by directly screwing a lens, where a male screw is formed on the external edge surface, to a cylindrical body where a female screw is provided on the internal surface, and positioning and fixing the lens. CONSTITUTION:On the external edge surface of a circular Fresnel lens 1, which is used for a semiconductor laser light source device and consists of, for example, a resin material, a male screw 1a is formed while a prescribed setting condition such as a pitch and a lead angle are being satisfied. On the other hand, a female screw 2a corresponding to the male screw 1a is notched for the prescribed length from an aperture part on the internal surface of a package 2 to be the cylindrical body of the lens. Thus, the lens 1 is screw-linked to the package 2, the focal position for a semiconductor laser element 3 is regulated, and then it is fixed. In addition, when the fixed position of the lens 1 is shifted, light emitted through the lens can be made convergent at a finite focal distance as well.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a lens mounting structure.

<Prior Art> Conventionally, in optical devices that require lens positioning and adjustment along the optical axis direction, a lens mounting structure as shown in FIGS. 6 and 7 has generally been adopted. There is.

That is, the lens mounting structure shown in FIG. 6 is adopted in a so-called semiconductor laser light source device, and the lens 20 is mounted at the outer end position of an intermediate cylinder 22 that is slidably housed inside a package 21. adhesive, etc. (
(not shown). The lens 20 is positioned and adjusted via the intermediate cylinder 22 so that its focal position can collimate the light emitted from the semiconductor laser element 23, and then the intermediate cylinder 22 is attached to the package 20 with adhesive or the like. It is fixed by adhering to.

Further, FIG. 7 shows another conventional example, in which the lens 25 fixed at the outer end position of the intermediate cylinder 24 is
The inner end of the intermediate barrel 24 is connected to the outer end of the lens barrel 26 by screwing, and the intermediate barrel 24 is fixed after being positioned and adjusted.

<Problems to be Solved by the Invention> Incidentally, all of the above-mentioned mounting structures have the following disadvantages. That is, the lens 20 (25
) is fixed to the intermediate cylinder 22 (24) and then attached to the package 21 or lens barrel 26, which increases the number of parts, increases the effort required for positioning and adjusting these parts, and increases the overall size. Furthermore, since the lens 20 (25) is fixed to the intermediate cylinder 22 (24) with adhesive or the like, it is not only difficult to remove it once it is attached, but also susceptible to vibrations from the outside. There is also a fear that the fixed position of the lens 20 (25) may change if the adhesive peels off due to deterioration of the adhesive itself over time.

The present invention was devised by focusing on such conventional disadvantages, and provides a lens mounting structure that allows easy positioning adjustment and can be fixed without using an adhesive or the like. It is intended to.

Means for Solving the Problems> In order to achieve the above object, the present invention consists of a lens having a male thread formed on the outer circumferential end face and a cylinder body having a female thread formed on the inner circumferential face. This configuration employs a structure in which the parts are positioned and fixed by screwing together.

Effect> According to the above configuration, the lens is directly screwed into the cylindrical body to adjust its position and then fix it, so the number of parts is reduced and the effort required for positioning adjustment can be saved. As a result of eliminating the need to fix the lens to the barrel with an adhesive, the inconveniences associated with the use of adhesives can be completely prevented.

<Example> Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a sectional view showing an example of a lens mounting structure according to the present invention, and Figs. 2 (a) to (c) are partially broken side views showing the shapes of various lenses used therein. It is a diagram.

The lens mounting structure shown in Fig. 1 is adopted in a semiconductor laser light source device, and the mounting structure shown in this figure uses a Fresnel lens 1 made of a resin material as shown in Fig. 2(a). It is configured. A male thread 1a is formed under predetermined setting conditions (pinch, lead angle, etc.) on the outer circumferential end surface of the circular flat substrate of the Fresnel lens 1, while the inside of the package 2, which is a cylinder, is formed with a male thread 1a. On the curved surface, a female thread 2a corresponding to the male thread 1a is formed over a predetermined length from the opening side thereof. Therefore, this Fresnel lens 1 is connected to the pan cage 2 by screwing, and the focal position with respect to the semiconductor laser element 3 is adjusted and fixed.

In addition, when forming the male thread 1a on this Fresnel lens 1, it is possible to prepare a corresponding threaded part in advance in the molding die used for molding, or to process the molded substrate. You can. When screwing this Fresnel lens 1 into the pan cage 2, it is necessary to rotate the Fresnel lens 1.
A concave portion (not shown) for inserting a rotating operation jig may be formed on the substrate, or a protrusion shaped along the circumference of one surface of the substrate may be formed on one surface of the substrate, as shown in FIG. Part 5
It is sufficient to form the notch portions 6 for the rotation operation jig set at a plurality of predetermined locations. In addition, the lens used in such a mounting structure is not limited to the Fresnel lens 1 described above,
For example, as shown in FIG. 2(b), an aspherical lens 7 having a male thread 7a formed on the outer peripheral end surface of the substrate or an aspherical lens 7 as shown in FIG.
It goes without saying that a convex lens 8 having a male thread 8a directly formed on the outer peripheral end surface as shown in c) may also be used.

By the way, the mounting structure constructed using the Fresnel lens 1 has the following advantages. First, the Fresnel lens l in this mounting structure is fixed at a position where the distance X between its outer surface and the semiconductor laser element 3 coincides with the focal path Mf of the Fresnel lens 1 itself, as shown in FIG. 4(a). If this is done, the light emitted from the semiconductor laser element 3 will pass through the Fresnel lens 1 and become parallel light before being emitted. Alternatively, if the fixed position of the Fresnel lens 1 is adjusted so that the distance X is larger than the focal length f of the Fresnel lens 1, as shown in FIG. The light that passes through the lens 1 and exits will be focused on a finite focal path @It. Therefore, in this mounting structure, the Fresnel lens 1
It becomes possible to arbitrarily set the focal position of the light emitted from the semiconductor laser element 3 by simply adjusting the fixed position of the plain text.

Next, FIG. 5 shows another example of the lens mounting structure according to the present invention. The mounting structure in this example is constructed using the same Fresnel lens 1 as described above, and a male thread 1a is formed on the outer peripheral end surface of the substrate. In this mounting structure, a stepped portion is provided on the inner circumferential surface of the lens barrel lO as a cylinder, and a female thread 10a of a predetermined length is formed on the small diameter side of the stepped portion. therefore,
In this mounting structure as well, the Fresnel lens 1 is positioned and fixed to the lens barrel lO by screwing, as in the above embodiment. Further, in order to further securely fix the Fresnel lens 1 in this configuration, a ring 11 as shown by the imaginary line in FIG. 5 may be attached by screwing from one side or both sides of the Fresnel lens 1.

Note that a detailed explanation of this embodiment will be omitted since it is the same as the above embodiment.

<Effects of the Invention> As explained above, according to the present invention, a lens having a male thread formed on the outer peripheral end face is directly screwed into a cylinder body having a female thread formed on the inner peripheral face. Since the positioning is adjusted and then fixed, the number of parts can be reduced and the effort required for positioning adjustment can be reduced compared to the conventional example, and the overall size can be reduced. In addition, as a result of eliminating the need to fix the lens to the barrel with adhesive,
Not only can the occurrence of inconveniences such as peeling due to the use of adhesives be completely prevented, but also the lens can be removed as necessary.

[Brief explanation of the drawing]

1 to 5 relate to embodiments of the present invention, FIG. 1 is a sectional view showing an example of a lens mounting structure, and FIG. 2(a)
〜(c) and FIG. 3 are partially cutaway side views showing the shapes of various lenses used in this, and FIG. 4(a)
, (b) is an explanatory diagram for explaining the advantage of the mounting structure using a Fresnel lens, and FIG. 5 is a sectional view showing another example of the lens mounting structure. Moreover, each of FIG. 6 and FIG. 7 is a sectional view showing a lens mounting structure according to a conventional example. In the figure, numeral 1 is a Fresnel lens, 1a is a male thread, 2 is a package (cylindrical body), and 2a is a female thread. Figure 5

Claims (1)

[Claims] (1) A lens mounting structure comprising a lens having a male thread formed on its outer circumferential end face and a cylinder body having a female thread formed on its inner circumferential face, both of which are positioned and fixed by screwing together.