JPH0214008Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an illumination device using an optical fiber bundle in which light from a light source device is transmitted through an optical fiber bundle and emitted from an end face of the optical fiber bundle.

When it is impossible to bring a light source close to the area that requires illumination and illuminate the area directly, such as when observing the inside of a body cavity using an endoscope, a light source is installed in the light source device as shown in Figure 1. The light from the light source lamp 1 is condensed by a condenser 2 such as a parabolic reflector and a condenser lens, or an ellipsoidal reflector, and an optical fiber bundle 3 for illumination is collected.
The light enters the incident end surface 4 of the optical fiber bundle 3, is transmitted through the optical fiber bundle 3, and is emitted toward the region from the exit end surface 5 of the optical fiber bundle 3 located near the region, illuminating the region. A lighting device is used.

The optical single fibers forming the optical fiber bundle 3 used in this type of lighting device have a core material made of glass or plastic with a high refractive index coated with a coating material made of glass or plastic with a low refractive index. It is something. Therefore, the opening angle θ of the single fiber is
is determined by the refractive index of the core material and the refractive index of the coating material, and in a normal optical single fiber, θ is about 60°. Therefore, in a normal optical fiber bundle formed from normal optical single fibers, only the emitted light within the range of the aperture angle θ can be obtained from the exit end face 5, and the illumination range is limited to a narrow range of about 60°. It's limited.

Therefore, in order to illuminate a wider area than 60°,
Conventionally, as shown in FIG. 2, a concave lens 6 was provided in front of the exit end face 5 to diffuse light. However, if the concave lens 6 has a diameter comparable to the diameter of the optical fiber bundle 3, a portion of the illumination light emitted from the exit end face 5 will be blocked by the edge of the concave lens 6, and the peripheral portion of the illumination light will be blocked. The amount of light decreases significantly. In order to prevent this, if the diameter of the concave lens 6 is made larger than the diameter of the optical fiber bundle 3, if an illumination device is attached to the endoscope, the tip of the endoscope to be inserted into the body cavity can be attached to the concave lens. As the diameter of No. 6 becomes larger, the diameter must be increased, which increases the pain for the patient who inserts the tip. In addition, with normal concave lenses, there is a limit to the curvature of the lens surface, which limits the illumination range.
The disadvantage was that concave lenses, which could not be expanded up to about 100 degrees, but could extend the illumination range further, were difficult and expensive to produce.

As other conventional examples, an opaque diffusion plate such as opal glass is provided in front of the exit end face 5 to diffuse the light, or a material with a refractive index different from that of the cover lens is placed in the center of the cover lens provided on the exit end face. There are some that are designed to diffuse light by embedding a large amount of fine particles. However, according to these examples, there is a lot of light that travels backwards due to the opaque diffuser plate and buried particles, and the scattering loss becomes large, and when the amount of effective transmitted light is taken into account, the transmission loss becomes large, and the amount of light generated in the light source device increases. The drawback was that light could not be used effectively.

Furthermore, as another conventional example, an optical fiber bundle is formed by bundling optical fibers, twisting one end of the bundle, and fixing the optical fibers at the end to each other. By finishing the exit end face 5 perpendicularly and smoothly to the optical axis of the optical fiber bundle, the optical axis of each optical single fiber is tilted with respect to the optical axis of the optical fiber bundle, and the optical axis of each optical single fiber is tilt the end face of the single fiber,
Some have diffused illumination light. However, in this example, the angle of the twist cannot be made too large, so the illumination range is limited to about 90 degrees, and the periphery of the optical fiber bundle can accommodate more light than an optical fiber bundle that is not twisted. Since the number of optical single fibers is reduced, there is a drawback that the amount of illumination light tends to be insufficient in the peripheral area.

The present invention has been made to solve the above-mentioned problems, and provides a lighting device that has a wide illumination range and can effectively utilize the light generated by the light source.

Hereinafter, according to the preferred embodiment shown in the attached drawings,
The present invention will be explained in detail.

In this embodiment, the illumination light generated by the light source device is incident on the incident end face of an optical fiber bundle that can be used for illumination, the illumination light is transmitted through the optical fiber bundle, and the illumination light is transmitted from the exit end face of the optical fiber bundle. Although the point of emission is the same as that of conventional lighting devices, in this example,
As shown in FIG. 3, in front of the exit end face 5 of the optical fiber bundle 3 that can be used for illumination, a transparent diffuser member 7 in the shape of a disk having approximately the same diameter as the optical fiber bundle 3 is installed along the optical axis of the optical fiber bundle 3. A transparent spherical body having a refractive index lower than that of the diffusing member 7 is fixed to the optical fiber bundle 3 coaxially with the optical fiber bundle 3 by a fixing member (not shown) or bonded with an adhesive. 8 are housed side by side along a single plane.

According to this embodiment, as shown in FIG. 4, the light emitted from the exit end face 5 of the optical fiber bundle 3 is diffused differently depending on its exit angle and the positional relationship between the spherical body 8 and the exit point. do. Light a that is incident on the surface of the spherical body 8 at an angle larger than the critical angle is totally reflected on the surface, changes its optical path significantly, and is diffused. A part of the light incident on the surface of the spherical body 8 at an angle smaller than the critical angle, like light b, enters the spherical body 8, exits from the spherical body 8, and exits from the diffusing member 7. Each is refracted at a larger angle with respect to the optical axis of the optical fiber bundle 3 and diffused.

The lighting device according to the present invention has a refractive index of the spherical body 8,
The illumination range and its light distribution vary depending on conditions such as the refractive index of the diffusing member 7 and the size and number of the spherical bodies 8. In addition, a spherical body 8 built into the diffusion member 7
may be arranged in double rows as long as they are arranged along a single plane. By appropriately selecting the above conditions, it is possible to perform illumination that matches the desired illumination range and light distribution.

Materials for the above-mentioned diffusion member 7 include epoxy resin (refractive index: 1.52 to 1.57), polycarbonate (refractive index: 1.58), polystyrene (refractive index: 1.60),
Plastic or glass with a high refractive index such as optical glass (refractive index: 1.5~) can be used, and materials for the spherical body 8 include PMMA (refractive index: 1.49), CR-
Plastic or glass having a low refractive index such as 39 (refractive index: 1.48) can be used, and the spherical body 8 can also be formed of air (refractive index: 1.0).

When forming the spherical body 8 with air, air bubbles may be mixed into the molten material of the diffusion member 7, and the air bubbles may be enclosed within the diffusion member 7 when the molten material solidifies. In addition, Figures 5A and 5
As shown in the semi-finished state in Figure B, the hemispherical recess 9
It is also possible to form the spherical body 8 as shown in the completed state in FIG. 6 by bonding together two glass or plastic plates 10 provided with the recesses 9 with each other.

In the spherical body 8 of the present invention, the refractive index of the spherical body 8 may be higher than the refractive index of the diffusing member 7, contrary to the above-described embodiment. In that case, as shown in FIG. 7, a part of the light emitted from the exit end face 5 of the optical fiber bundle 3 is emitted from the spherical member 8 when it enters the spherical member 8, like lights c and d. When the light is released from the optical fiber bundle 3 and when it is emitted from the diffusing member 7, it is refracted at a larger angle with respect to the optical axis of the optical fiber bundle 3 and diffused.

In this embodiment, the material for the diffusion member 7 may be the low refractive index plastic or glass described above, and the material for the spherical body 8 may be the above-mentioned high refractive index plastic or glass.

Alternatively, the present invention can be implemented even if spherical bodies 8 having higher and lower refractive indexes than the diffusing member 7 are mixed in a single diffusing member 7.

Further, in FIGS. 3, 4, and 7, the diffusion member 7 is brought into close contact with the injection end surface 5, but the diffusion member 7
The present invention can be implemented even if a gap is provided between the injection end face 5 and the injection end face 5.

According to the illumination device using the optical fiber bundle according to the present invention, the illumination light can be diffused by the diffusion member provided with the spherical bodies, and a wide range can be illuminated. Moreover, by changing the number, size, and refractive index of the spherical bodies, it is possible to change the irradiation range and light distribution of illumination light, and it is possible to perform optimal illumination depending on the application. In addition, unlike the case where an opaque diffuser plate is provided or the case where a large amount of fine particles with different refractive indexes are embedded in the central part of the cover lens, there is almost no transmission loss. Furthermore, unlike the case where a concave lens is provided, even if the diameter of the diffusing member is the same as the diameter of the optical fiber bundle, the light is less likely to be blocked by the peripheral surface of the diffusing member, so the light generated by the light source device can be used effectively. There is no need to increase the diameter of the emission part of the illumination device in order to provide sufficient illumination. Therefore, by making the emission part of the illumination device small in diameter, when the illumination device is attached to an endoscope, it is possible to reduce the pain caused to the patient when the illumination device is inserted into the patient's body cavity.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an illumination device using a general optical fiber bundle, Fig. 2 is a longitudinal cross-sectional plan view showing an emitting part of a conventional example using a concave lens, and Fig. 3 is a plan view showing an example of an embodiment of the present invention. 4 is an optical path diagram of the same embodiment. FIG. 5A is a longitudinal sectional plan view showing an example of the diffusion member of the embodiment in a semi-completed state. FIG. 5B is a semi-completed view of FIG. 5A. Front view showing the state diffusion member, No. 6
This figure is a longitudinal sectional plan view showing the completed state of the diffusing member shown in FIGS. 5A and 5B, and FIG. 7 is an optical path diagram of another embodiment of the present invention. 3... Optical fiber bundle, 4... Incident end face, 5... Outgoing end face, 7... Diffusion member, 8... Spherical body.

Claims (1)

[Claims for Utility Model Registration] (1) Consisting of a light source device for illumination, an optical fiber bundle for transmitting light from the light source device, and a transparent diffusing member provided in front of the exit end surface of the optical fiber bundle, An illumination device using an optical fiber bundle, characterized in that a plurality of transparent spherical bodies having a different refractive index from the diffusion member are arranged side by side along a single surface as a diffusion member. (2) An illumination device using an optical fiber bundle according to claim (1), in which the refractive index of the spherical body is lower than the refractive index of the diffusing member. (3) A lighting device using an optical fiber bundle according to claim (2) of the utility model registration, wherein the spherical body is formed of air. (4) An illumination device using an optical fiber bundle according to claim (1), in which the refractive index of the spherical body is higher than the refractive index of the diffusing member. (5) The optical fiber bundle according to claim (1) of the utility model registration is used, in which spherical bodies having a refractive index lower and higher than that of the diffusing member are arranged in a single diffusing member. lighting equipment.