JPS60144710A - Lens - Google Patents

Abstract

PURPOSE:To reduce the number of parts in a barrel part and to reduce man- hour for barrel assembling by providing plural screw threads in the edge part of a lens so that the minor diameter of these screw threads is larger than the effective diameter on optical design of the lens. CONSTITUTION:Screw threads 14 whose minor diameter is larger than the diameter of a light 13 connecting an effective diameter 12a on optical design of a lens face 10a and an effective diameter 12b on optical design of a lens face 10b are provided in an edge part 11 of a lens 10 formed with a synthetic resin, and two recessed parts 15 used for rotation of the lens 10 are provided on the side of the lens face 10a in positions on the outside of the diameter of the light 13. In case of assembling, lens assembling jigs are engaged with recessed parts 15 provided on the lens face 10a of the lens 10, and the lens 10 is rotated while fitting a fitting part 18 of the lens 10 to a fitting part 17 of a lens holding frame 16 until a contacting face 20 of the lens 10 is brought into contact with a contacting face 19 of the lens holding frame 16.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a lens that can be used in video cameras and the like.

2. Description of the Related Art Structures of Conventional Examples and Their Problems In recent years, efforts have been made to simplify the method of assembling lenses and reduce the number of lens barrel parts in lens barrels for video cameras and the like.

Hereinafter, conventional lenses will be explained first with reference to the drawings. FIG. 1 is an assembly diagram of a conventional lens, in which a lens 1 is inserted into a lens holding frame 2 and fixed by a lens holding ring 3. As shown in FIG. Further, the edge portion 4 of the lens 1 is coated with ink 4a to prevent reflection of light.

FIG. 2 is an assembly diagram of another conventional lens, in which a lens 6 is inserted into a lens holding frame 6 and fixed by a lens holding clip 7. Furthermore, black ink 8a is applied to the edge portion 8 of the lens 5 to prevent reflection of light.

However, in the above configuration, the number of parts is large, and it takes a lot of man-hours to insert the lens into the lens holding frame without contaminating the lens. Further, there was a problem in that it took a lot of man-hours to apply anti-reflection ink to the edge of the lens.

OBJECTS OF THE INVENTION An object of the present invention is to provide a lens that enables a reduction in the number of parts in the lens barrel and a reduction in the number of man-hours when assembling the lens barrel.

Structure of the Invention The lens of the present invention has a plurality of screw threads on the edge of the lens, and the root diameter of the screw threads is configured to be smaller than the effective diameter in optical design of the lens. This makes it possible to reduce the number of lens barrel parts and reduce the number of man-hours when assembling the lens barrel.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 shows a sectional view of a lens according to an embodiment of the present invention. In FIG. 3, the edge IIS' 11/C, v7 surface 10a of the lens 10 molded from synthetic resin is shown.
A screw thread 14 having a root diameter larger than the light ray 13 connecting the optically designed effective diameter 12a of the lens surface 10b and the optically designed effective diameter 12b of the lens surface 10b is provided at a location larger than the light ray 13. Two recesses 16 for rotating the lens 10 are provided on the lens surface 10a side. Further, in order to center the lens on the side of the lens surface 10b opposite to the recess 15, a fitting part 18 that fits into the fitting part 17 of the lens holding frame 18 is provided, and furthermore, an optical axis of the lens 10 is provided. In order to fix the position in the direction, the lens 1o is provided with an abutment surface 2o that abuts on an abutment surface 19 provided on the lens holding frame 16.

A method for assembling the lens of this example configured as described above will be described below.

First, the recess 1 provided in the lens surface 10a of the lens 1o.
6 to hold the lens assembly jig, and then attach the lens holding frame 1.
While fitting the fitting part 17 of 6 and the fitting part 18 of the lens 10, attach the lens 100 to the contact surface 19 of the lens holding frame 16.
Screw until the contact surface 2o contacts.

As described above, according to this embodiment, by integrally molding the threads on the edge of the lens, the number of lens holding parts can be reduced, and since the threads reflect light diffusely, there is no need to ink the edges of the lens. This reduces the number of man-hours required when assembling the lens barrel.

Next, other embodiments of the present invention will be described with reference to the drawings.

FIG. 4 shows a sectional view of a lens according to another embodiment of the present invention. In FIG. 4, the edge part 22fC of the lens 21 molded from synthetic resin is formed by a light ray 24 connecting the optically designed effective diameter 23a of the lens surface 21a and the optically designed effective diameter 23b of the lens surface 21b. A screw thread 26 with a root diameter is provided, and a convex portion 26 for rotating the lens 21 is provided on the lens surface 2 at a location larger than the light beam 24.
There are two locations on the 1a side. In addition, in order to fix the position of the lens 21 in the optical axis direction on the side of the lens surface 2Ib opposite to the convex portion 26, a contact surface 29 is provided on the lens 21 that contacts a contact surface 28 provided on the lens holding frame 27. In order to center the lens on the lens surface 21b side, a fitting part 31 that fits into the fitting part 30 of the lens holding frame 27 is provided.

A method for assembling the lens of this example configured as described above will be described below.

if, the convex portion 2 provided on the lens surface 21a of the lens 21
6 with a jig, and while fitting the fitting part 30 of the lens holding frame 27 and the fitting part 31 of the lens 21, the abutting surface 29 of the lens 21 is fitted to the abutting surface 28 of the lens holding frame 26. Screw it in until it makes contact.

In addition, in the above-mentioned embodiment of the present invention, the lens, the retaining part, and the fitting part are integrally molded from resin, but the material is not limited to resin, and any material can be used as long as it obtains a similar structure. Anything is fine. For example, glass can be used. Further, although there are two retaining parts, the number of engaging parts is not limited to two, but may be any number as long as it has the function of rotating the lens. For example, it may be placed in one place.

In addition, although the fitting part is provided on the opposite side of the lens surface where the retaining part is provided, the fitting part is not limited to the opposite side of the retaining part, but is located at the center of the lens. It may be installed anywhere as long as it has the function of dispensing. For example, it can be provided on the same lens surface as the retaining part.

Effects of the Invention As is clear from the above explanation, the lens of the present invention has a plurality of ridges on the edge portion, and the valley diameter of the ridges is larger than the effective diameter in the optical design of the lens. This reduces the number of lens barrel parts, and the provision of screw threads allows the light to be diffusely reflected by the threads, eliminating the need for anti-reflection inking, and reducing the number of lens barrel parts. An excellent effect can be obtained in that the number of man-hours during assembly can be reduced.

Furthermore, by providing a retaining part on the lens surface of the lens that is located outside the effective diameter of the lens in terms of its optical design, the retaining part can be used to rotate the lens using a jig for assembling the lens. This makes it easier to screw the lens into the lens holding frame, thereby improving work efficiency, and
Since the structure is suitable for automatic assembly, an excellent effect can be obtained in that the number of man-hours when assembling the lens barrel can be significantly reduced.

Furthermore, by configuring the fitting part with the lens holding member to be provided outside the effective diameter of the optical design of the lens,
Compared to a structure in which the lens and the lens holding member are simply screwed together, an excellent effect can be obtained in that it is possible to prevent the lens from tilting or the optical axis from shifting due to play in the threaded portion.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional lens, FIG. 2 is a sectional view of another conventional lens, FIG. 3 is a sectional view of a lens according to an embodiment of the present invention, and FIG. 4 is a sectional view of another conventional lens. FIG. 2 is a cross-sectional view of a lens according to an example. 10...lens, 14...i, mountain, 1
6...Engaging part, 18...White fitting part, 21...
... Lens, 26... Lee Jisan, 26...
...Engagement part, 31... Fitting part. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 3

Claims (3)

[Claims] (1) Provide multiple screw threads on the edge of the lens, and
A lens characterized in that the root diameter of the thread is set to be larger than the effective diameter in optical design of the lens. (2) The lens according to claim (1), characterized in that a retaining portion for rotating the lens is provided on the lens surface portion of the lens, and is located outside the effective diameter of the lens in terms of optical design. lens. (3) The lens according to claim (1), wherein the fitting portion with the lens holding portion is provided outside the effective diameter of the optical design of the lens.