JPH09146014A - Fiberscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a simple-structure and inexpensive fiberscope which does not require electric power, which is strong against vibration and which is constituted so that a part to be observed can be observed at the angle in a wide angle range by arranging a diffusion plate at the image forming point of an enlargement lens. SOLUTION: The image of the part to be observed is formed on the end surface of an image transmission body 2 by an objective lens system 1. The formed image is transmitted in the transmission body 2 so as to form the image on the other end. Then, the image is formed on the diffusion plate 4 arranged at the image forming point of the enlargement lens 3 by the lens 3 so as to diffuse light. Besides, the image formed on the plate 4 is enlarged and observed by a convex lens 5. The lens system 1 can be selected according to a use and provided with a focus fixing lens, a zoom lens or an automatic focusing mechanism. A multiple optical fiber made of plastic is used as the transmission body 2. Besides, the various kinds of transparent plates including a diffusion material or a lenticular lens are used as the plate 4.

Description

Detailed Description of the Invention

[0001]

The present invention does not use electric power,
The present invention relates to a projection-type fiberscope that forms an image directly on a screen from an image transmission body.

[0002]

2. Description of the Related Art A fiberscope is used as an effective observation means for observing the inside of a human body, observing inside a pipe, and a place where the eyes of a driver cannot reach the eyes such as a blind spot. Such a fiberscope is basically composed of an objective lens, an image fiber, and an eyepiece side lens component. The eyepiece lens part is an eyepiece that directly observes the exit side of the image fiber, or C
The parts to be observed on the screen of the CRT via the CD were used.

[0003]

However, since the eyepiece lens forms a virtual image in front of the lens, the observer cannot observe it without bringing the eye close to the lens. Therefore, it was impossible to observe while operating other devices, or to observe images by a plurality of observers at the same time.

When observing on a CRT screen through a CCD, it is advantageous that a plurality of observers can observe at the same time. However, when using CCD, the equipment becomes large,
There were various problems such as high price, power requirement, and weakness to vibration, and the problem was that the usage conditions were very narrow.

An object of the present invention is to provide a fiberscope which has a simple structure, is inexpensive, does not require electric power, is strong against vibration, and can be observed from a wide angle.

[0006]

The gist of the present invention is a fiberscope in which an objective lens, an image transmitter, a magnifying lens, a diffusing plate and a convex lens are sequentially arranged from one side, and an image forming point of the magnifying lens is provided. It is located in the fiberscope with the diffuser plate.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings. FIG. 1 is an example of the overall configuration of the fiberscope of the present invention. By the objective lens system (1), the observed portion is imaged on the end surface of the image transmission body (2). The formed image propagates through the image transmission body (2) and reproduces the image at the other end.
An image is formed on the diffusion plate (4) by the magnifying lens (3) to diffuse the light. Further, the image formed on the diffusion plate by the convex lens (5) is magnified and observed.

The objective lens system (1) can be selected according to the application, and a fixed focus lens, a wide-angle lens, a zoom lens, or an automatic focusing mechanism can be provided. It is also possible to provide a moving mechanism to move the monitoring position arbitrarily. Furthermore, in order to facilitate monitoring of dark areas and the like, it is possible to install an illumination device such as a light guide independently or integrally with the objective lens system.

A plastic multi-optical fiber is used for the image transmitter (2). As the structure of the plastic multi-optical fiber, a circular light transmitting island portion (hereinafter referred to as “pixel”) having a diameter of 5 to 100 μm is 2,000 to 30,000.
It is preferable to use the one in which 0 pieces are arranged in the form of a bag in the sea area.

If the outer diameter of the multi-optical fiber becomes large, the rigidity becomes large and it becomes difficult to bend. Therefore, it is necessary to select the pixel diameter and the number of pixels so that the outer diameter does not become larger than necessary. If the pixel diameter is too small, the transmission loss will be large, making it difficult to transmit a good image. In addition to the difficulty in transmission, the outer diameter of the entire multi-optical fiber becomes very large and the rigidity becomes large, making it difficult to bend. On the other hand, if the number of pixels is too small, the resolution will be lowered when observing a wide range, making it difficult to transmit a good image. Pixel size is 10-5
It is more preferable that the number of pixels is 0 μm and the number of pixels is about 5,000 to 20,000. However, in use in a field where rigidity is not a problem, it is preferable that the outer diameter of the multi-optical fiber is large in order to obtain a bright image. It is also possible to stack a plurality of multi-optical fibers and further increase the number of pixels to increase the outer diameter.

As the multi-optical fiber, plastic type, quartz type, multi-component glass type and the like can be used. However, considering that it is flexible and is not easily broken, that it is easy to handle, and that it is inexpensive, a plastic product is preferable.

The magnifying lens (3) can be selected according to the application, and the focal length and the magnifying power can be arbitrarily selected. A short focal length is preferable in order to make the entire fiberscope compact. The magnifying power is determined in combination with the magnifying power of the convex lens (5). It is also possible to combine a plurality of lenses for the purpose of correcting aberrations.

The diffusion plate (4) is installed at the image forming point of the magnifying lens. The diffusing plate has a function of diffusing light and expanding an observable angle. As the diffusion plate, various transparent plates containing a diffusion material, a lenticular lens, etc. are used. It is preferable to select a diffuser that maintains the brightness within the range visible to the human eye and that allows observation from a required angle.

The convex lens (5) is not particularly limited, but a plano-convex lens and a Fresnel lens are preferable. In order to make the entire fiberscope compact, it is preferable to select the lens diameter according to the required image size.

For the purpose of reducing reflection of external light, it is preferable to install a cover on the end surface of the lens.

[0016]

【Example】

Examples 1 and 2 A fiberscope having the same structure as that shown in FIG. 1 and having the specifications shown in Table 1 was manufactured. A very good image could be observed with any of the fiberscopes.

[0017]

[Table 1]

[0018]

The fiberscope of the present invention has a simple structure, is inexpensive, does not require electric power, is resistant to vibration, and can be observed from a wide angle.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the overall configuration of a fiberscope of the present invention.

FIG. 2 is a cross-sectional view of a plastic multi-optical fiber used as the image transmission body of the present invention.

[Explanation of symbols]

 1 Objective Lens 2 Image Transmitter 3 Magnifying Lens 4 Diffuser 5 Convex Lens 6 Observer's Eye 7 Optical Transmission Island

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshinori Sumi 20-1 Miyuki-cho, Otake-shi, Hiroshima Mitsubishi Rayon Co., Ltd. Central Research Laboratory (72) Osamu Oumi 3816 Noborito, Tama-ku, Kawasaki-shi, Kanagawa Mitsubishi Rayon Co., Ltd. Tokyo Technology and Information Center

Claims (1)

[Claims] 1. An objective lens, an image transmitter, a magnifying lens,
A fiberscope in which a diffusion plate and a convex lens are sequentially arranged from one side, and the diffusion plate is arranged at an image forming point of a magnifying lens.