JPH04109734U - Lens blackout coating - Google Patents

Abstract

(57) [Summary] [Purpose] Applying light-shielding coating to the lens surface to maintain the specified performance of the lens system and to form a good image by blocking ghosts and the like that are harmful to image formation. [Structure] The lens frame 4 in which the lens 2 is installed is set in alignment with the mounting seat 13a and the reference hole 13b of the bed 13 provided on the atomizer 10, using the boss 4a for positioning as a reference. lens 2
A tampo printing pad 12 that can be raised and lowered is provided above facing the surface, and after applying a light-shielding paint to the surface of the pad tip 12a, the tampo printing pad 12 is lowered and pressed against the two surfaces of the lens to be coated. The light-shielding paint 3 is applied by transferring the light-shielding paint to the position and range.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

In this invention, the effective light flux for image formation on the lens surface of the lens constituting the optical system is The present invention relates to a light shielding means for blocking harmful light beams that pass through.

0002

[Conventional technology]

Generally, when an optical system forms an image of a subject on the surface of a photosensitive material, each lens in the optical system Ghosts caused by reflection on the lens surface and the inner surface of the lens frame, and light entering from the periphery of the lens. Harmful light flux is blocked as much as possible so that a good image can be formed.

0003 Conventionally, in order to block light beams harmful to image formation such as ghosts, a lens was placed in front of the lens system. Light-shielding measures such as installing a hood or a light-shielding frame between lenses or behind the lens system Measures are being taken to prevent this. Technical means related to these have already been developed According to Publication No. 107111, a light shielding mask is provided in the air space of the lens near the subject side. It is well known for its optical means.

0004

[Problem that the idea aims to solve]

However, in the case of optical systems such as zoom lenses, it is difficult to block harmful light beams. Even if you try to place a light-shielding frame in a position where the lens system has a good At the position of the large lens surface, the light-shielding frame irregularly contacts and deforms. For example, the shooting screen In a light-shielding frame with a hollow rectangular shape, only a part of the long side near the optical axis is in contact with the frame. Because the short side is not in contact, the contact area between the light-shielding frame and the lens surface is deformed, causing harmful light flux. Not only is it not possible to block the lens correctly, but it is also caught between the lenses. The elastic body of the light-shielding frame itself presses the lenses against each other, changing the distance between the lenses and blocking the light. There are drawbacks that have a negative impact on academic performance. Also, install the lens hood mentioned above. In this case, the focal length of the zoom lens changes, so harmful light flux is blocked at all focal lengths. Even if a light-shielding frame is installed at the rear of the lens system, it is not possible to use a reflective lens. It has drawbacks such as being ineffective when there is a distance from the surface.

[0005] The present invention solves these problems and can be used without adversely affecting the optical system. Requires the provision of light-shielding coatings for lenses that can block harmful light beams extremely effectively. The purpose of the title is

[0006]

[Means to solve the problem]

This objective can be achieved by either means a or b below.

[0007] (a) In an optical system that has multiple lenses to form an image of a subject, a specific reflective surface is Effective light effective for image formation formed by the optical system on one or both sides of the lens. Applying a light-shielding coating or printing that allows light flux to pass through and blocks harmful light flux that is harmful to images. A light-shielding coating on the lens that features

[0008] (b) In paragraph a, painting or printing on the lens surface shall be applied to the lens or lens frame. A light-shielding coating for a lens characterized by being processed based on a positioning means that can be .

[0009]

【Example】

An example of the present invention shown in Figure 1(a) showing the state of the light-shielding coating applied to the lens surface. A top view, a sectional view of the same side shown in Figure 1(b), and a lens coated with light-shielding coating shown in Figure 2 are assembled into the lens barrel. Side sectional view showing the soldered state and positioning of the light-shielding coated lens and lens frame in Figure 3 A front view showing the means, a perspective view showing the lens positioning means in FIG. 4, and a lens frame in FIG. A side cross-sectional view showing the positioning means of the lens frame and the light-shielding coating based on the positioning means of the lens frame in Figure 6. A side cross-sectional view showing the lens unit assembled into the lens barrel and the light-shielding coating shown in Figure 7. This will be explained with reference to a side sectional view showing processing means for the equipment. However, the present invention is limited to this example. It is not determined. The present invention eliminates the above-mentioned problems and allows the light to enter the optical system. The lens surface light shielding means for blocking harmful light beams was constructed as follows.

0010 That is, as shown in FIGS. 1(a) and 1(b), the optical axis is set on one side of the circular lens 2. The surface of the lens 2 is left in a rectangular shape with each side symmetrical in the center, and the outer side is, for example, A light-shielding coating 3 is applied using a matte black light-shielding paint. The two surfaces of the lens The rectangular exposed area is important for forming a good image of the optical system 1 (including the lens barrel). The area through which the effective light flux passes, and the painted area outside it blocks the harmful light flux. It is a mask for blocking light.

[0011] Generally, the inner shape of a light-shielding mask is formed in a similar shape to the photographed image. The shape of the screen frame differs depending on the size of the screen frame, and the shape shown in Figure 1(a) is for a 35mm camera. This is an example applied to a full-size shooting screen. In this way, the lens 2 is shielded from light. The lens 2 coated with the coating 3 is integrally fitted into the first lens frame 4 as shown in FIG. The light-shielding coated surface 3 is positioned in the direction of the photosensitive material 9 and the adjacent lens 6 is It is incorporated into the second lens frame 7 and constitutes a part of the rear group of the optical system 1. And before The light-shielding coating 3 most effectively blocks harmful light beams among the lens groups constituting the optical system 1. The second surface 2a of the lens 2 (in the direction of the photosensitive material 9) blocks out the light. and , for example, when the optical system 1 is affected by an object that has partially high and irregular brightness. A part of the incident light flux passes through the lens 2 and then passes through the light shielding coating 3. If not, a ghost is generated by reflecting the second surface 2a of the lens 2 as the primary reflecting surface. Then, the first surface 6a of the adjacent lens 6 is used as a secondary reflecting surface to reflect the characteristics of the mutual curvature. The ghost that tries to enter the surface of the photosensitive material 9 through mutual reflection is By applying the light-shielding coating 3, it is completely absorbed and the lenses after the lens 6 are completely absorbed. Harmful light flux entering the system is blocked.

0012 As mentioned above, the light-shielding coating 3 is formed in a rectangular shape following the photographic screen. Therefore, the lens 2 coated with the light-shielding coating 3 is located at a predetermined position in the optical system 1. The shape and correctness of the photographic screen frame 9a, which is determined and incorporated and located in front of the photosensitive material 9, is It is necessary to respond appropriately. Therefore, in order to position the lens 2, as shown in FIG. For example, a part of the outer periphery of the lens 2 is cut to form a parallel portion 2c. The light-shielding coating 3 is applied so that the long sides of the rectangle are parallel to each other, with reference to After determining the engagement position, it corresponds to the parallel portion 2c of the lens 2 provided in the lens frame 2b. The lens 2 and the lens frame 2b are positioned by fitting into the parallel parts. The lens frame 2b has a positioning flang provided on its outer periphery with respect to the optical system 1. The photographing screen frame 9a and the light-shielding coating are incorporated into the optical system 1 with reference to the frame 2d. 3, a predetermined positioning is performed. Although not shown, the above The optical system 1 and the housing having the photographing screen frame 9a are positioned relative to each other. ing. In addition, in the case of a plastic lens 5 shown in FIG. A notch for positioning with respect to the optical system 1 in a part of the flange 5a provided on the outer periphery. After providing a groove 5b and applying the light-shielding coating 3 with the notch groove 5b as a reference, the optical system 1 is By assembling it into a predetermined position, the photographing screen frame 9a and the light-shielding coating 3 are positioned. It is decided. In addition, in the case of the lens 2 which is a glass lens, the position shown in FIG. In addition to the mounting means, as shown in FIG. A boss 4a is provided for positioning, and after the lens 2 is integrally fitted, the boss 4a is The light shielding coating 3 is applied to the second surface 2a of the lens 2 as a reference.

[0013] The first lens assembly incorporating the lens 2 coated with the light-shielding coating 3 in this manner The lens frame 4 positions the first lens frame 4 provided on the second lens frame 7 as shown in FIG. The lens 6 which is fitted into the groove 7a and adjacent to the right side is assembled and the lens 6 is fitted into the groove 7a. It is positioned at a predetermined position in the optical system 1 as a lens unit and as part of the rear group. Incorporated. A housing (not shown) is provided with the optical system 1 and the photographic screen frame 9a. (without) means that the mounting position of the optical system 1 is determined by mutually provided positioning means. The light shielding coating 3 and the photographing screen 9a are aligned in mutual directions correctly. has been done.

[0014] For example, in order to apply the light-shielding coating 3 to the lens 2, the coating shown in FIG. Use container 10. The outer diameter of the first lens frame 4 falls onto the bed 13 surface of the coating device 10. A circular mounting seat 13a having an appropriate depth is provided, and the boss 4a is mounted on the seat surface of the mounting seat 13a. A reference hole 13b into which the first lens frame 4 is positioned is provided. There is.

[0015] An upper portion of the bed 13 facing the mounting seat 13a is movable up and down in the direction of the arrow. A tampon printing pad 12 that operates automatically is provided, and the tip end 12a of the pad has a predetermined shape, for example. The hollow rectangular shape is hollowed out, and the area around it is the effective diameter of the two lens surfaces to be painted. It has an outer diameter at least as large as It is.

[0016] Then, a predetermined light-shielding paint is applied to the pad tip 12a of the pad printing pad 12. After applying the tampo printing pad 12, lower the pad tip 12a to the lens. The light-shielding coating 3 is transferred by pressing onto the two surfaces of the lens.

[0017] The lens is mounted on the mounting seat 13a of the coating device (printing device) 10 configured as described above. 2 into which the first lens frame 4 is inserted and the coating position is determined. 4a and the reference hole 13b, and then set the pad tip 12a. The tampo printing pad 12 coated with a certain amount of light-shielding paint is lowered with a predetermined pressing force. The light-shielding coating is applied to a predetermined position and range of the two lens surfaces by pressing against the two lens surfaces. The material is transferred and the light-shielding coating 3 is applied. Then, finish painting the two surfaces of the lens. The tampo printing pad 12 that has been applied rises and returns to its regular position, and the tip end portion 12 of the pad is moved again. In order to apply the light-shielding paint 3 to the new lens 2 surface after the light-shielding paint is applied to a. will be on standby.

[0018] In this way, the light shielding coating 3 is applied to a predetermined position on the lens 2 surface. After the lens frame 4 is positioned and assembled into the second lens frame 7, the lens 6 is incorporated to form a lens unit, and then the optical system is assembled as a part of the rear group of the optical system 1. 1. Note that a large number of the lens frames 4 in which the lenses 2 are incorporated are Set on the bed 13 of the coating machine (printing machine) 10 and simultaneously apply the light-shielding coating 3. Of course, it is also possible to do the same.

[0019]

[Effect of the idea]

The light-shielding coating of the lens according to this invention prevents harmful harmful effects from occurring in extremely effective optical system positions. The light flux can be blocked and the effective light flux that is effective for image formation can pass through correctly. As a result, good images are always formed.

[Brief explanation of drawings]

FIG. 1(a) is a front view showing the state of the light-shielding coating applied to the lens surface according to one embodiment of the present invention. FIG. 1(b) is a sectional view of the same side. FIG. 2 is a side sectional view showing a state in which a light-shielding coated lens according to an embodiment of the present invention is assembled into a lens barrel. FIG. 3 is a front view showing means for positioning a light-shielding coated lens and a lens frame according to an embodiment of the present invention. FIG. 4 is a perspective view showing lens positioning means according to an embodiment of the present invention. FIG. 5 is a side sectional view showing a positioning means for the lens frame. Figure 6 is part 1 of the present invention.
FIG. 3 is a side cross-sectional view showing a state in which a lens unit coated with a light-shielding coating is assembled into a lens barrel based on the lens frame positioning means according to the embodiment. FIG. 7 is a side sectional view showing a processing means for light-shielding coating according to one embodiment of the present invention.

[Explanation of symbols]

1...Optical system (including lens barrel) 2, 6...Lens 2a...First reflective surface 3...Shading coating 4...First lens frame 4a...Boss 5...Plastic lens 6a...Second reflective surface 7...Second lens frame 9...Photosensitive material 9a... Shooting screen frame 10... Painter 12...Tampo printing pad 12a...Tip of pad 13...Bed 13a...Mounting seat 13b...Reference hole

Claims (2)

[Scope of utility model registration request] Claim 1: In an optical system that forms an image of a subject using a plurality of lenses, an effective light beam that is effective for forming an image formed by the optical system passes through one or both surfaces of the lens that has a specific reflective surface. A light-shielding coating for a lens characterized by being coated with a light-shielding coating or printing that blocks harmful light beams that are harmful to images. 2. The light-shielding coating for a lens according to claim 1, wherein the coating or printing on the lens surface is performed based on positioning means provided on the lens or lens frame.