JP2002148501A - Mold lens with holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily constitute a mold lens with a holder. SOLUTION: The mold lens with the holder is integrated with a lens holder 5 by an insert molding. The structure of the mold lens integrated with the lens holder is suitably to be adopted to a microlens such as a photographic lens for a monitor camera, the optical coupling lens of a photoconductive module for optical communication or the like and the objective lens of the recording and reproducing head of an optical information recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic lens for a surveillance camera, an optical coupling lens for a light guide module for optical communication, and an objective lens for a recording / reproducing head for an optical information recording medium. It relates to a molded lens.

[0002]

2. Description of the Related Art In a molded lens with a holder, a method for fixing a lens holder to the lens body is as follows.
It is known that a lens holder is composed of a metal frame and a press ring, a lens is put in the metal frame, and the lens is sandwiched by the press ring. However, since the size of a photographing lens of a monitoring camera, an optical coupling lens of a light guide module for optical communication, an objective lens of an optical pickup, and the like are as small as several millimeters or less,
When such a method is employed, workability is extremely poor.

[0003] Therefore, in general, a bonding method in which a molded lens body is placed in a metal lens holder and fixed using an adhesive in a positioned state, or a press-fitting method in which the lens body is pressed into a metal lens holder. The method has been adopted.

[0004]

However, in the method using an adhesive, it is necessary to manage the amount of the adhesive to be an appropriate amount. If the amount is small, sufficient adhesive strength cannot be obtained, If the amount is too large, adverse effects such as the adhesive falling off and adhering to the lens surface will occur. Further, depending on the type of the adhesive, there is an adverse effect such as generation of an irritating gas, and the handling is also troublesome.

On the other hand, in the method of press-fitting into a metal lens holder, it is necessary to precisely control both dimensions. If the accuracy is poor, the lens body cannot be fixed with a sufficient fitting force to the metal lens holder, or if the fitting is too tight, the press-fit lens body will be distorted and the lens performance will be degraded. appear.

In particular, in recent years, the production of plastic lenses by injection molding has been actively carried out with high precision, and has been widely used, for example, for optical systems of optical information recording media. In addition, not only the spherical surface (radius of curvature) of the lens, but also a high-precision lens having an aspheric surface or a special shape is manufactured. Therefore, the press-fitting method is not suitable as a method for attaching a lens holder to such a high-precision molded lens because distortion is likely to occur in a high-precision lens body.

An object of the present invention has been made in view of such a point, and an object of the present invention is to make it possible to easily attach a lens holder to a high-precision molded lens body.

[0008]

In order to solve the above-mentioned problems, in the present invention, a lens holder is integrated with a molded lens body by insert molding. That is, the molded lens with holder of the present invention is characterized in that the lens holder is integrated with the molded lens body by insert molding.

Here, an aperture stop can be formed in the lens holder to be inserted.

Further, when the lens holder is integrated with the molded lens body while being sandwiched by the outer peripheral portion of the molded lens body from both sides in the thickness direction, the bonding strength therebetween Is preferred because of the high

Alternatively, the lens holder may be integrated with the molded lens body such that the molded lens body is fitted in the cylindrical portion.

Further, in order to increase the joint strength between the two, a filling portion to be filled with an injection molding material at the time of injection molding of the molding lens is formed in a part of the lens holder, and the filling portion is injected into the filling portion. The cured and hardened portion of the molded lens body may enhance the bonding strength with the lens holder.

In this case, if a positioning portion for positioning the filling portion at a predetermined position in the cavity of the injection mold is formed in the lens holder, the lens holder can be accurately positioned in the cavity of the injection mold. Positioning can be performed, and the positioning operation can be simplified.

Here, the positioning portion may function as a positioning portion of a mold lens with a holder. In this case, there is an advantage that the positioning operation when the molded lens with the holder is mounted on the optical pickup device or the like is simplified.

As a molding method of the molded lens, it is possible to adopt a compression method instead of the injection molding.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a molded lens with a holder and a method of manufacturing the same according to the present invention will be described with reference to the drawings.

(Example 1) FIG. 1A is an explanatory view showing a method of insert-molding a mold lens with a holder using an injection molding method. As shown in this figure, a cavity 4 is formed between the injection molds 2 and 3.
In the mold open state, a metal lens holder 5 is set in the cavity 4. The lens holder 5 has a ring shape, and is arranged such that its outer peripheral surface is in close contact with the inner peripheral surface of the cavity 4.

After the mold is clamped in this state, a plastic, which is an injection molding material, is injected from the nozzle port 7 of the injection molding die. Here, the lens holder 5 of this example has a nozzle port 7
A through hole 8 for filling the plastic is formed at a portion corresponding to.

A positioning groove 9 for positioning the lens holder 5 in the cavity is formed in the lens holder 5 so that the through hole 8 matches the nozzle opening 7. On the side of the injection mold, a positioning pin 10 that can be inserted into the positioning groove 9 protrudes into the cavity. Therefore, the positioning of the lens holder 5 in the cavity can be easily performed.

Thereafter, plastic is injected into the cavity through the nozzle port 7. Plastic is injected from the nozzle port 7 through the through hole 8. When the plastic is cured, a molded lens 12 with a holder in which the lens main body 11 is integrated with the lens holder 5 as shown in FIG. 1B is obtained.

In the molded lens 12 with the holder, since the plastic is also filled in the through hole 8 penetrating the lens holder 5, the lens holder 5
And the lens body 11 are strengthened. Also,
An annular convex portion 13 projecting slightly inward is formed on the inner peripheral surface of the lens holder 5, and this portion is sandwiched by the outer peripheral portion of the lens body 11 molded from above and below. Therefore, the lens holder 5 and the lens body 11 are firmly integrated.

A positioning groove 9 is formed on the end surface of the lens holder 5. The groove 9 can be used as it is as a positioning part when assembling the lens holder with the holder to a device such as an optical pickup.

The parting line 14 between the injection molds 2 and 3 is located at about 1/2 to 3/4 of the height of the lens holder 5, and the lens holder 5 is in a stable state in the cavity. And it is designed to be easily installed.

In order to increase the bonding strength between the lens body 11 and the lens holder 5, as shown in FIG. 2, instead of the through hole 8, a groove or cut for filling an injection molding material is provided in the lens holder 5. The notch 21 may be formed, and an injection molding material may be filled therein and cured.

Further, the lens holder 5 to be inserted
Can also have functionality. For example, in the case of a photographic lens of a surveillance camera, there is a case where the image quality is improved by an aperture. In such a case, as shown in FIG.
If an annular stop 22 is further provided on the inner peripheral surface of the annular convex portion 13 formed on the lens holder 5A, the molded lens with the holder after integration is provided.
An aperture function is provided.

The annular groove 24 formed on the outer peripheral surface of the lens holder 5A is used for fixing the lens holder 5A during injection molding. This annular groove 2
4 can be utilized as a positioning part when being incorporated into a product to be incorporated after molding.

(Embodiment 2) The above example is an example in which the molded lens body is formed inside the lens holder. Conversely, the lens holder is inserted into the outer periphery of the lens body. Insert molding can also be performed. FIG. 4A is an explanatory view showing a molding method of the molded lens 32 with a holder in which the lens holder 31 is integrated as described above, and FIG. 4B shows the molded lens 32 with the obtained holder. It is sectional drawing.

In the case of this embodiment, the cross-sectional shape of the lens holder 31 can be a simple shape different from the case of the above-described embodiment. Therefore, the lens holder can be manufactured at low cost.

In this case, the outer diameter of the lens holder 31 can be not only a circle but also an irregular shape having a square or a guide groove. In FIG. 4, parts corresponding to the respective parts in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted.

[0030]

As described above, in the molded lens with holder of the present invention, the lens holder is integrated with the lens body by insert molding. Therefore, it is possible to eliminate troublesomeness when assembling a small lens into a metal frame, and to manufacture the lens with high accuracy. Further, handling of the lens after molding is easy.

Further, according to the present invention, by forming an aperture stop in a lens holder to be inserted, a molded lens with a holder having functionality can be easily formed.

Further, in the present invention, the lens holder is integrated with the molded lens body while being sandwiched by the outer peripheral portion of the molded lens body from both sides in the thickness direction. Alternatively, the lens holder is integrated with the molded lens body such that the molded lens body is fitted in the cylindrical portion. Therefore, the coupling strength between the two can be increased.

Further, according to the present invention, since a filling portion to be filled with the injection molding material at the time of injection molding of the molding lens is formed in a part of the lens holder, the mold injected into the filling portion and cured is formed. The strength of coupling with the lens holder can be increased by the lens body.

In addition, in the present invention, since the lens holder is formed with a positioning portion for positioning the filling portion at a predetermined position in the cavity of the injection mold, the lens holder is provided with a lens in the cavity of the injection mold. The holder can be positioned with high accuracy, and the positioning operation can be simplified.

Further, since such a positioning portion can function as a positioning portion when being incorporated into a product into which the molded lens with a holder is incorporated, it is convenient.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an insert molding method for a molded lens with a holder according to the present invention, and a sectional view of the molded lens with a holder obtained.

FIG. 2 is an explanatory view showing a modified example of the molded lens with holder of FIG. 1;

FIG. 3 is an explanatory view showing a modified example of the molded lens with holder of FIG. 1;

FIG. 4 is an explanatory view showing another example of the insert molding method of the molded lens with holder according to the present invention, and a sectional view of the molded lens with holder obtained.

[Explanation of symbols]

 2, 3 Injection mold 4 Cavity 5, 5A, 31 Lens holder 7 Nozzle port 8 Through hole 9 Positioning groove 10 Positioning pin 11 Lens body 12, 32 Molded lens with holder 13 Projection 21 Groove or notch 22 Opening aperture

Claims (7)

[Claims] 1. A molded lens with a holder, wherein a lens holder is integrated with a molded lens body by insert molding. 2. The mold lens according to claim 1, wherein an aperture stop is formed in the lens holder. 3. The molded lens body according to claim 1, wherein the lens holder is sandwiched between outer peripheral portions of the molded lens body from both sides in a thickness direction of the molded lens body. Molded lens with holder. 4. The lens holder according to claim 1, wherein the lens holder is integrated with the molded lens body such that the molded lens body is fitted in a cylindrical portion thereof. Molded lens with holder. 5. The filling part according to claim 1, wherein a filling portion for filling an injection molding material at the time of injection molding of a mold lens is formed in a part of the lens holder. A molded lens with a holder, wherein integration with the lens holder is strengthened by a part of the molded lens body injected into the filling portion and cured. 6. The molded lens with a holder according to claim 5, wherein a positioning portion for positioning the filling portion at a predetermined position in a cavity of the injection mold is formed in the lens holder. . 7. The molded lens with a holder according to claim 6, wherein the positioning portion functions as a positioning portion of the molded lens with a holder.