JP3088134B2 - Light source device for endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention adjusts the amount of illumination light incident on illumination light transmitting means such as a light guide fiber for illumination of an endoscope by blocking a part of the illumination light emitted from a light source lamp. And a light source device for an endoscope.

[0002]

2. Description of the Related Art In this type of endoscope light source device,
Conventionally, in general, the diaphragm blade is moved by an arbitrary amount inward from the outer edge side of the illumination light path to block a part of the illumination light path.
The amount of illumination light incident on the illumination light transmission means of the endoscope is adjusted.

[0003]

However, when the aperture blade is set to 1
In the case where only one sheet is provided, if the illumination light path is largely blocked in order to reduce the amount of illumination light, only the illumination light that has passed through the periphery of the illumination light path enters the illumination light transmitting means. Also, in the case where two diaphragm blades are provided and the diaphragm blades are moved inward from both sides so as to sandwich the illumination optical path, only the light passing through the central portion of the illumination optical path is illuminated when the light amount is reduced. Light enters the light transmission means.

However, the illuminating light that has passed through the peripheral portion of the illumination optical path is greatly refracted at the peripheral portion of the condensing lens and the like, and wavelength dispersion occurs. Unevenness or the like occurs. Further, with the illumination light passing only through the central portion of the illumination light path, the spread angle (light distribution angle) of the illumination light illuminating the subject becomes small, and the illumination around the subject becomes extremely dark.

Therefore, according to the present invention, no matter how the illumination light amount is adjusted, the ratio between the illumination light passing through the peripheral portion of the illumination light path and the illumination light passing through the central portion does not change, and the quality of illumination light is always constant. An object of the present invention is to provide a light source device for an endoscope that can make illumination light incident on illumination light transmitting means.

[0006]

In order to achieve the above object, an endoscope light source device according to the present invention transmits illumination light of an endoscope by blocking a part of illumination light emitted from a light source lamp. In the light source device for an endoscope which adjusts the amount of illumination light incident on the means, the illumination of the light source lamp and the illumination light transmitting means is performed such that the direction of the central axis does not coincide with the optical axis of the illumination light. A coil spring that is extendably and contractably disposed in an illumination light path between the light incident end and a coil spring expansion and contraction unit that expands and contracts the coil spring by an arbitrary amount; The illumination light quantity incident on the illumination light transmitting means from the light source lamp is adjusted by extending and retracting the coil spring between the coil springs.

[0007]

An embodiment will be described with reference to the drawings.

In FIG. 1, reference numeral 10 denotes an endoscope. Inside an observation window 12 and an illumination window 13 provided at a distal end of an insertion portion 11, an image incident end 14a of an image guide fiber bundle 14 and an illumination light guide are provided. The illumination light emitting end 15a of the fiber bundle 15 is arranged.

The image output end 14b of the image guide fiber bundle 14 is guided to an eyepiece 18 projecting from an operation section 17, and the image of the subject transmitted to the image output end 14b is converted into an eyepiece 19 by an eyepiece. It can be enlarged and observed. Reference numeral 21 denotes a light receiving element for detecting the brightness of light reaching the eyepiece 18 through the image guide fiber bundle 14.

A light guide connector 23 connected to the operation unit 17 by a flexible connecting pipe 22 and a signal connector 24 connected to an output end of the light receiving element 21 are detachably attached to the light source device 30. Is provided.

Light source lamp 3 fixed in light source device 30
1, a converging lens 32 is provided, and illumination light emitted from the light source lamp 31 is irradiated by the converging lens 32 with the illumination light incident end of the illumination light guide fiber bundle 15 at the end of the light guide connector 23. Focus on 15b.

The illumination light passes through the illumination light guide fiber bundle 15 and irradiates the subject from the illumination window 13, whereby an image of the subject brightly illuminated is transmitted from the observation window 12 through the image guide fiber bundle 14. , At the eyepiece 18.

Between the condenser lens 32 and the illumination light incident end 15b of the illumination light guide fiber bundle 15,
In a normal state, the coil spring 35 which is in close contact is arranged. The center axis of the coil spring 35 is disposed so as to be orthogonal to the optical axis 36 of the illumination optical path 100 between the light source lamp 31 and the illumination light guide fiber bundle 15.

This coil spring 35 has only one end (the upper end in FIG. 1) fixed to the light source device 30, and the other end is pulled to extend the spring length by an arbitrary amount. When the pulling force is released, the state is reduced again to the close contact state shown in FIG. Therefore, by expanding and contracting the coil spring 35, the illumination light path 100
The area of the coil spring 35 that blocks the illumination light therein changes, and the illumination light amount incident on the illumination light guide fiber bundle 15 can be changed.

One end of a flexible string 39 wound around a pulley 38 is attached to the free end side of the coil spring 35, and the pulley 38 is rotated by a motor 40 to stop it. An arbitrary amount of the string 39 is wound around a pulley 38 and a coil spring 35
The amount of elongation can be adjusted.

An input terminal of a comparator 42 whose output terminal is connected to a drive circuit 41 of the motor 40 receives a set value which can be freely set by an operator and an output signal from the light receiving element 21. The rotation angle of the motor 40 is controlled so that the output value of the light receiving element 21 always matches the set value, that is, so that the brightness of the observation image observed in the eyepiece 18 is always constant. Coil spring 35
Of the light guide fiber bundle 1 for illumination
The amount of illumination light incident on 5 is automatically adjusted. Note that the adjustment of the illumination light amount may be manually performed.

In this embodiment, as shown in FIG. 2, when the coil spring 35 is completely contracted and in close contact, the illumination light path 100 is completely blocked by the coil spring 35, and No illumination light is incident on the light guide fiber bundle 15.

However, if the string 40 is wound around the pulley 38 by rotating the motor 40 and the coil spring 35 is extended as shown in FIG.
The number of windings of the coil spring 35 that blocks the light decreases, and the amount of illumination light incident on the illumination light guide fiber bundle 15 increases.

Moreover, since the windings of the coil spring 35 that block the illumination light path 100 are always located at equal intervals in the illumination light path 100, the illumination light guide fiber bundle 1
Irrespective of how the amount of illumination light incident on 5 is increased or decreased, the illumination light in the central portion and the illumination light in the peripheral portion always enter uniformly.

FIG. 4 shows a coil spring 45 according to a second embodiment of the present invention, which is a single wire that is not wound in a coil shape between a light shielding coil portion 45a and a tension spring portion 45b. By providing the part 45c, it is possible to obtain a fully open state in which the illumination optical path 100 is hardly obstructed.

FIG. 5 shows a third embodiment of the present invention. One end of a coil spring 55 is attached to an arm 56 without using a pulley, and the arm 56 is connected to the motor 5.
7, and is driven to rotate. In this case, when the arm 56 is rotated greatly, the coil spring 55 is completely separated from the illumination optical path 100,
The illumination light amount in the fully open state can be made incident on the illumination light guide fiber bundle 15.

The present invention is not limited to the above embodiments. For example, the coil spring is not necessarily orthogonal to the illumination optical axis unless the direction of the center axis is the same as the illumination optical axis. However, the amount of illumination can be adjusted by expansion and contraction.

[0023]

According to the light source device for an endoscope of the present invention, the coil spring is extended and contracted between the light source lamp and the illumination light transmitting means of the endoscope to reduce the amount of illumination light incident on the illumination light transmitting means. Because of the adjustment, the illumination light in the central part and the illumination light in the peripheral part always enter the illumination light transmission means evenly, no matter how the illumination light quantity is increased or decreased by expanding or contracting the coil spring. It has an excellent effect of obtaining illumination light of a certain quality.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a first embodiment.

FIG. 2 is a front view of the coil spring according to the first embodiment.

FIG. 3 is a front view of the coil spring according to the first embodiment.

FIG. 4 is a front view of a coil spring according to a second embodiment.

FIG. 5 is a front view of a coil spring according to a third embodiment.

[Explanation of symbols]

15 Light guide fiber bundle for illumination (illumination light transmission means) 31 Light source lamp 35 Coil spring 36 Illumination optical axis 40 Motor (coil spring expansion / contraction means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) A61B 1/00-1/32 G02B 23/26

Claims (1)

(57) [Claims] 1. An endoscope light source device for adjusting the amount of illumination light incident on an illumination light transmitting means of an endoscope by blocking a part of illumination light emitted from a light source lamp.
A coil spring disposed so as to be extendable and contractible in an illumination light path between the light source lamp and the illumination light incident end of the illumination light transmitting means so that the direction of the central axis does not coincide with the optical axis of the illumination light. A coil spring extending / contracting means for extending / contracting the coil spring by an arbitrary amount, and extending / contracting the coil spring between the light source lamp and the illumination light transmitting means, thereby providing the illumination light transmitting means from the light source lamp. A light source device for an endoscope, wherein the amount of illumination light incident on the light source is adjusted.