JPS622561Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved set of plastic lenses for projecting or collecting light.

FIGS. 1 to 3 are drawings showing conventional examples. As shown in FIG. A projected image as shown in the figure is created. In FIG. 2, a portion a is a ray close to the optical axis (an image of the central ray), and a portion b is an image due to aberrations of peripheral rays.

In order to prevent the projected image from becoming like this, the third
Multiple lenses (two lenses here) as shown in the figure.
There will also be a lens set attached. That is, the separation ring 1 is installed in the opening at one end of the funnel-shaped hold case 13.
Two projecting lenses 11 are set at a constant interval with a lens 4 in between, and are positioned using a holding ring 15, and a light source 12 is attached to the other end. In this case, the projected image is only part a in FIG. 2, and the image is good. However, while the separation ring 14 is essential to accurately set the distance between both lenses 11,
Precision is required in manufacturing the opening of the hold case 13 in order to align the axes of both lenses.

The present invention was made for the purpose of providing a plastic lens set for projecting or condensing light that can eliminate the above-mentioned drawbacks, and its gist is that two or more lenses arranged coaxially with each other A joint made of a light-shielding member is interposed in the center of each lens to integrally form them, and this joint allows the adjacent lenses to be positioned concentrically while regulating their relative positions in the optical axis direction. be.

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

In FIGS. 4 and 5, parts corresponding to the conventional example shown in FIG. 3 are indicated by numbers incremented by 50, and detailed explanation thereof will be omitted.

The two light projecting lenses 61 are joined at their centers (near the optical axis) by circular joints 67 at predetermined intervals and with their axes aligned. This joint is made of a light-blocking material. Specifically, both lenses 61 and the joint part 67 are integrated by two-color molding (the joint part 67 is blackish). A projection image substantially similar to that in the example is obtained (see FIG. 7). Note that when the joint 67 is formed of a light-shielding material, the joint 67 does not allow light to pass through, but the light passing through this part has a negative effect on the lens performance as described below, so it is essentially a Imaging characteristics are not impaired.

The joint portion 67 may be made of a transparent material. In that case, as shown in FIG.
Light passing through areas other than 7 becomes image c, but the light passing through the joint 67
The light passing through becomes an image d slightly protruding from the image c. This is because the joint portion 67 acts as a lens 1 and the focal length of the lens system becomes longer.

In order to prevent such a situation, a protrusion 78 may be provided on the rear surface side of one lens 71 (on the opposite side to the joint portion 77), as shown in FIG. This protrusion 78 acts as a convex lens and corrects the focal length shift caused by the joining portion 77.

In each of the above-mentioned lens sets, the two lenses 61 and 71 are integrated by the joint portions 67 and 77 at a predetermined interval and with their axes coincident. ) is no longer necessary, and the processing accuracy of the opening of the hold case 13 does not need to be relatively rough. In addition, the lens set including the joint parts 67, 77 and the lenses 61, 71 can be easily molded and manufactured using a mold bisected by the diameter line, since the joint part is arranged across the diameter line of the lens. Costs go down.

Note that both lenses 61 and 71 can also be integrated by an appropriate number (for example, two) of joints located on the outer periphery of each, and in this case, almost the same effect as described above can be obtained. can get. However, in this case, it is desirable that the joint be made light-shielding.

Further, as shown in FIG. 9, a normal lens 81 and a deformed lens 86 may be integrated at a joint 87. The deformed lens has a spherical entrance surface 86a, an exit surface 86b, and a planar total reflection surface 8.
It is equipped with 6c. The light source 82 is positioned in a cylindrical housing portion 86d that extends integrally from the entrance surface 86a side. The lens set of this example is set in the camera as is and is used as an illumination means to illuminate the subject when it is dark and enable autofocusing, but the positioning of the lens 81 and the deformable lens 86, the positioning of the light source 82, etc. are not required at all. It is unnecessary, compact and easy to adjust.

In addition, in the explanation so far, the lens is a light projecting lens, but the lens may be a light collecting lens provided in front of the photometric light receiving element of the camera.

As described above, according to the present invention, a plurality of plastic lenses for projecting or condensing light can have their relative positions correctly defined in the optical axis direction with a simple joint structure, and can be positioned concentrically. This results in the effect that the imaging characteristics of the lens are not substantially impaired by the interposition of the joint.

[Brief explanation of the drawing]

FIG. 1 is a front view of a conventional light projecting lens, FIG. 2 is an explanatory diagram of an image projected by the light projecting lens shown in FIG. 1, and FIG. 3 is a front view of a conventional example. Figures 4 and 5 are side and front views showing one embodiment of the invention, Figures 6 and 7 are projected images of the above embodiment, and Figure 8 is another embodiment of the invention. Front view,
FIG. 9 is a front view showing still another embodiment of the present invention. Explanation of symbols of main parts, 61, 71, 81, 8
6... Lens, 62, 72, 82... Light source, 63
... Hold case, 65 ... Presser ring, 67,7
7, 87...Joint part, 78...Protrusion part.

Claims (1)

[Scope of utility model registration request] At least two lenses arranged coaxially and adjacent to each other, and a joint that joins both lenses at the center are integrally formed, and the joint is made of a light-shielding material. Plastic cleansing set.