JPS6053296B2 - Optical equipment accessory mounting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an accessory attachment device configured to be detachably attached to an optical device, such as a photographic lens for a camera.

Conventional models have a filter placed in the middle or rear of the shooting system.When using a regular glass filter, the pits are exposed by the glass filter, so even if you replace the color filter, the pits will not change. There isn't.
In the case of gelatin filters, there are only a few types, but when color reproduction is required, gelatin filters, which are available in many types, are used.

Ordinary glass filter ″−＾7■゜啼 ■…A
-, ＾ U■ When used in the middle or rear of the lens optical system, the so-called optical path length changes. Therefore, when a gelatin filter is attached, the optical path length becomes short, resulting in what is called a front focus, and in order to align the pits, the optical system must be moved toward the image plane. Pit alignment is performed using a distance ring, but the optical system must be moved further toward the image plane than the infinity position, but the distance ring normally acts as a stopper at the infinity position when using a glass filter and cannot be rotated further. . Therefore, it is not possible to take pictures near infinity, which is possible with a gelatin filter, and the shooting range is limited. Further, in a zoom lens, correction is usually made with a glass filter at each focal length, but when a gelatin filter is attached, the optical path length changes, causing pit movement due to zooming, which impedes quick shooting performance.

When using a gelatin filter to eliminate the above-mentioned drawbacks, the present invention eliminates the change in optical path length compared to a normal glass filter by attaching a gelatin filter to a normal glass filter. It is the one that has been eliminated.

Examples will be described in detail below with reference to the drawings.

FIG. 1 shows one embodiment. In the figure, 1 is a main body of an accessory mounting device, and the main body 1 is inserted into an insertion section provided in a photographic lens barrel, which will be described later.

1a is a flange portion that engages with the outer diameter portion of the lens barrel, and 1b is an opening for an optical path.

A fixed filter 2 made of glass or plastic is fixed to this opening 1b. Reference numeral 3 designates a gelatin filter that is attached to the attachment device main body 1 so that it can be held or removed, and 4 is an attachment member.

The mounting member 4 has a U-shape, a horseshoe shape, or a circular shape, and has a central portion 4.
a is an opening for the optical path, a notch is provided from the outer periphery of the mounting member to the optical path opening to provide elasticity, and the knob 4
bi and 4b2, and when the knobs 4b1 and 4b are pushed in the direction of arrow A-B, both ends 4c and 4d contract, and when released, they are in the free position as shown in the figure.

The mounting device main body 1 is provided with an engaging portion that engages the mounting member 4.

These engaging portions 1C1, 1C2, and 1C3 can be adjusted to 4c, 4d, and 4e of the mounting member 4 by pushing them against the main body 1 while pinching the knobs 4b1 and 4b2 of the mounting member 4, and releasing the knobs.
The structure is such that each part of the main body 1 engages with each of the protruding parts 1C1, 1C2, and 1C of the main body 1. In FIG. 1, the fixed filter 2 is shown extending from the opening 1b of the mounting device main body 1 for the sake of explanation. However, when an optical filter and a gelatin filter are used together as in the object of the present invention, they are fixed to the opening 1b of the main body.

An example of the use of the accessory mounting device shown in FIG. 1 is shown in FIG.

A gelatin filter 3 of a size that closes the optical path opening 1b of the mounting device main body 1 is placed or covered on the opening 1b, and the mounting member 4 is inserted from above the gelatin filter 3 into the engaging portions 1C1, 1C2, and 1C3 of the mounting device main body 1. By engaging with the gelatin filter 3, the gelatin filter 3 is fixed. When the attachment device 1 shown in FIG. 1 is inserted into the insertion opening provided in the photographic lens barrel L, the attachment device 1 is prevented from coming off by the click ball 5 of the click mechanism.

As described above, the present invention has a structure in which a thin film-like accessory such as a gelatin filter can be held or removed from an accessory attachment device that can be attached to and detached from an optical device, thereby reducing the change in optical path length due to the use of a gelatin filter. I was able to resolve the inconvenience of focusing.

Additionally, since the combination of a glass filter and a gelatin filter does not change the optical path length, it is possible to avoid focus shifts due to zooming. Furthermore, many effects can be achieved, such as the ability to easily change filters to suit the shooting situation.

[Brief explanation of drawings]

FIG. 1 is a developed view showing one embodiment of the present invention. FIG. 2 is a sectional view of the lens barrel showing how it is attached to the photographic lens. 1... Mounting device main body, 3... Gelatin filter, 4... Mounting member.

Claims (1)

[Claims] 1 Consists of a main body that is inserted into an insertion section provided in a photographic lens barrel and a mounting member that is attached to the body, the main body having an optical path opening and an engaging part that engages with the mounting member, and the mounting member A cutout extending from the opening and the outer periphery of the mounting member to the optical path opening is provided to provide elasticity, a filter is disposed between the main body and the mounting member, and the mounting member is engaged with the engaging portion of the main body. An accessory mounting device for an optical instrument, characterized in that the accessory is fixed with a holder.