JP2002116328A - Optical transmission element - Google Patents

Abstract

[PROBLEMS] To provide an optical transmission element capable of transmitting light with high efficiency by an optical fiber integrated body and contributing to obtaining an output image with high brightness and high contrast. An optical fiber integrated body composed of a plurality of integrated optical fibers has one end face formed by one end of each optical fiber and the other end face formed by the other end of each optical fiber. In each of the optical fibers 4, the outer periphery of the core 4a is surrounded by the cladding 4b. Light is transmitted from one end face 2a of the optical fiber integrated body 2 to the other end face. One end face 2a of the optical fiber integrated body 2 is processed so that one end of each optical fiber 4 has a lens shape having a light collecting action.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission element for transmitting light by an optical fiber integrated body, for example, a cathode ray tube (Cathode Ray Tube), a low-light amplifier (Image Intens).
ifier) or the light emitting surface of a fluorescent tube,
It can be used to transmit light by being attached to a photoelectric conversion element such as D.

[0002]

2. Description of the Related Art An optical transmission element 101 shown in FIG. 4 includes an optical fiber integrated body 102 and a phosphor 103 applied to one end face 102a of the optical fiber integrated body 102. The optical fiber assembly 102 includes a number of optical fibers 104.
And one end face 102a is formed by one end of the optical fiber 104, and the other end face is formed by the other end of the optical fiber 104. Each optical fiber 104 has a structure in which the outer circumference of a core 104a is surrounded by a clad 104b, and the core 104a and the clad 104b have different refractive indexes.

The light transmission element 101 constitutes a light emitting surface of, for example, a cathode ray tube, a low light amplifier, and the like.
3, the surface 103a side is evacuated, and the electron beam is incident thereon. The fluorescent light 106 emitted by the fluorescent substance 103 in the electron beam incident area reaches one end of the optical fiber 104 arranged in the area corresponding to the light emitting area as shown by a dashed line in the figure, and is transmitted to the core 104a of the optical fiber 104. And enters the core 104a while being reflected at the interface with the cladding 104b. As a result, the fluorescent light 106 is applied to one end face 102a of the optical fiber integrated body 102.
To the other end face and output as output light. In a cathode ray tube, a low light amplifying device, and the like, the optical fiber integrated body 102
The other end surface 102b is an output window surface polished smoothly, and an electron beam is controlled to form an optical image.

[0004]

Conventionally, one end face 102a of the optical fiber assembly 102 has been polished smoothly. Therefore, of the light 106 emitted from the phosphor 103, the light incident on the core 104a at one end of the optical fiber 104 is transmitted to the other end surface, but the light incident on the clad 104b is transmitted to the other end surface due to scattering or the like. Was not done. As a result, the light transmittance of the optical fiber integrated body 102 is reduced, and the brightness and contrast of the optical image on the other end surface, which is the output window surface, are reduced. Further, the phosphor 10
When the amount of light incident on the optical fiber 104 that does not correspond to the light emitting region of No. 3 increases, this causes blurring of the optical image on the output window surface.

[0005] An object of the present invention is to provide an optical transmission element that can solve the above problems.

[0006]

According to the present invention, there is provided an optical fiber integrated body composed of a plurality of integrated optical fibers, one end of which is one end of each optical fiber and the other end of which is one end of each optical fiber. An optical transmission element configured by the other end of each optical fiber, each optical fiber having a core and a clad surrounding the outer periphery of the core, and transmitting light from one end surface to the other end surface of the optical fiber integrated body. At
One end surface of the optical fiber integrated body is processed so that one end of each optical fiber becomes a lens shape having a light-condensing action. According to the configuration of the present invention, the traveling direction of the light reaching one end of the optical fiber constituting one end surface of the optical fiber integrated body is determined by the fact that one end of the optical fiber has a lens shape having a condensing action. To the core. As a result, the light can enter the core of the optical fiber corresponding to the light emitting region as much as possible and can be transmitted to the other end surface of the optical fiber integrated body.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical transmission element 1 shown in FIG. 1 comprises an optical fiber integrated body 2 and one end face 2 of the optical fiber integrated body 2.
and a fluorescent material 3 that covers a. The light transmission element 1 constitutes, for example, a light emitting surface of a cathode ray tube or a low light amplifying device, and the surface 3a of the phosphor 3 is evacuated. The optical fiber integrated body 2 is configured by bundling and integrating a large number of optical fibers 4, one end surface 2 a is formed by one end of each optical fiber 4, and the other end surface 2 b is formed by the other end of each optical fiber 4. It is configured. As shown in FIG. 2, each optical fiber 4 has a structure in which the outer periphery of a glass core 4a is surrounded by a glass clad 4b, and the core 4a and the clad 4b have different refractive indexes. ing. The optical fiber assembly 2 produces a thicker optical fiber by winding a glass lump serving as a clad 4b around a rod-shaped glass lump serving as a core 4a and pulling the glass lump downward while heating in a spinning furnace. It is manufactured by pulling out the optical fibers in a bundled state while heating them in a spinning furnace.

As shown in FIG. 3, one end face 2a of the optical fiber assembly 2 is processed so that one end of each optical fiber 4 becomes a microlens having a light condensing function.
The processing can be performed by, for example, polishing the one end face 2a of the optical fiber assembly 2 smoothly, and then corroding the one end of each optical fiber 4 so that the clad 4b is recessed from the core 4a. That is, the glass core 4a and the glass clad 4b have different components such that the refractive indices are different from each other, and the corrosiveness is different due to the difference in the components. The core 4a has a higher refractive index and generally a higher density than the cladding 4b, and therefore has a higher resistance to corrosion. The components of the cladding 4b can be selectively corroded based on the difference in the corrosiveness. An aqueous solution of hydrofluoric acid HF is used at room temperature as an etchant.
O ₃ may be appropriately added. Further, since the core 4a and the clad 4b are in close contact with each other and the components contained therein come and go, the amount of corrosion changes continuously. That is, in each optical fiber 4, the amount of corrosion can be gradually increased from the center of the core 4a toward the clad 4b. Thereby, one end of each optical fiber 4 can be formed into a microlens shape having a convex curved surface shape having a condensing function. As the corrosion method, for example, one end face 2a of the optical fiber integrated body 2 is immersed in an aqueous solution of hydrogen fluoride which is a general glass corrosion material, the aqueous solution is sprayed, and an ion beam is applied in a vacuum. A known method, such as sputtering, can be used. Typically, argon Ar is used as a sputtering material. The optical transmission element 1 is obtained by applying the fluorescent substance 3 to one end face 2a of the optical fiber integrated body 2 constituted by one end of the microlens-shaped optical fiber 4.

When the electron beam 5 is incident on the surface 3a of the phosphor 3, the phosphor 3 emits fluorescence 6 in the incident area. The fluorescent light 6 in the optical fiber 4 constituting the optical fiber integrated body 2 as shown by a dashed line in FIG.
An optical fiber 4 arranged in an area corresponding to the light emitting area
And enters the core 4a while being reflected at the interface with the cladding 4b. Thereby, the fluorescence 6
Is transmitted from one end face 2a to the other end face 2b of the optical fiber integrated body 2 and output as output light 7. In a cathode ray tube, a low light amplifying device, or the like, the other end surface 2b of the optical fiber integrated body 2 is used.
Is an output window surface polished smoothly, and an electron beam 5 is controlled to form an optical image on the output window surface.

According to the above configuration, the direction of travel of the fluorescent light 6 reaching one end of the optical fiber 4 constituting the one end face 2a of the optical fiber integrated body 2 is determined by the micro lens having one end which has a condensing function. Because of the shape, it can be changed from the cladding 4b to the core 4a as shown by a dashed line in FIG. As a result, the light emitted from the phosphor 3 can enter the core 4 a of the optical fiber 4 corresponding to the light emitting area as much as possible, and can be transmitted to the other end surface 2 b of the optical fiber integrated body 2. Therefore, the light transmittance of the optical fiber integrated body 2 can be increased, and the optical image formed on the output window surface can be made high in brightness and high in contrast. In addition, light incident on the optical fiber 104 that does not correspond to the light emitting area of the phosphor 103 is reduced, and the optical image formed on the output window surface can be prevented from being blurred.

The present invention is not limited to the above embodiment. For example, the core and the clad may be made of synthetic resin. Also,
In the above-described embodiment, an optical transmission element in which a phosphor is integrated with an optical fiber integrated body is shown. However, an optical transmission element without such a phosphor may be used. Such a light transmission element without a fluorescent material is used by attaching the other end side to guide light to a photoelectric conversion element such as a CCD.

[0012]

According to the present invention, it is possible to provide an optical transmission element capable of transmitting light with high efficiency by an optical fiber integrated body and contributing to obtaining an output image with high brightness and high contrast.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view of an optical transmission element according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an optical fiber assembly in the optical transmission element according to the embodiment of the present invention.

FIG. 3 is a partially enlarged longitudinal sectional view of an optical transmission element according to an embodiment of the present invention.

FIG. 4 is a partially enlarged longitudinal sectional view of a conventional optical transmission element.

[Explanation of symbols]

 Reference Signs List 1 optical transmission element 2 optical fiber integrated body 4 optical fiber 4a core 4b clad

Claims (1)

[Claims] 1. An optical fiber integrated body comprising a plurality of integrated optical fibers, one end of which is constituted by one end of each optical fiber and the other end is constituted by the other end of each optical fiber. And each optical fiber is
Having a core and a clad surrounding the outer periphery of the core,
In an optical transmission element for transmitting light from one end face to the other end face of the optical fiber integrated body, one end face of the optical fiber integrated body is processed so that one end of each optical fiber has a lens shape having a light collecting action. An optical transmission element characterized in that: