JPH0256648B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a light source device for an endoscope, and more particularly to a light source device for an endoscope that monitors light from a light source.

[Technical background of the invention and its problems]

For endoscope light source devices, information from the light source is used to calculate the exposure of the endoscope camera, to detect the presence or absence of light from the light source, or to automatically adjust the light to maintain the amount of light from the light source at all times. Photometry of light is being carried out. Generally, a light receiving element detects light that deviates from an optical path formed by a light source or reflected light. However, all of these methods use light that is deviated from the optical path, so the accuracy of the amount of light is poor, and in particular, those that use reflected light have large variations in the amount of light, which poses a problem in accuracy.

In view of this point, a technique disclosed in Japanese Patent Application Laid-Open No. 87526/1983 has been proposed. This is on the optical path between the light guide of the endoscope, which is detachably connected to the main body of the light source device for endoscopes, and the light source, which is provided on the main body and irradiates the light beam to the incident end surface of the light guide. , the tip of an optical transmission fiber is arranged, a light receiving element is connected to the rear end of this optical transmission fiber, and the monitor light from the light source is transmitted to the above light receiving element for photometry. The tip of the transmission fiber is notched diagonally so as to face the light guide, and the notch surface is mirror-finished so that light is taken in from the mirror-finished portion.

According to this, highly accurate photometry is certainly possible, but since the cutout surface is mirror-finished, it is expensive in terms of cost, and because it is a mirror-finish, it is difficult to effectively capture light into the photodetector by reflection. It has no drawbacks.

[Purpose of the invention]

This invention was made in view of the above circumstances, and its purpose is to provide a light source device for an endoscope that employs an optical transmission fiber that can inexpensively and effectively take in light from a light source. There is a particular thing.

[Summary of the Invention] That is, the present invention notches the distal end surface of the optical transmission fiber diagonally so as to face the light guide, and makes the notch surface rough, thereby facilitating processing and reducing diffused reflection. It is intended to allow direct light from the light source and reflected light from the end face of the light guide to be taken in.

[Embodiments of the invention]

The present invention will be described below based on an embodiment shown in the drawings. In Fig. 1, 1 indicates an endoscope, 2 is a light guide cable of the endoscope 1, 3 is a connector provided at the tip of the light guide cable 2, and 4 is a connector provided protruding from the tip surface of the connector 3. It is a light guide.

On the other hand, 5 indicates a light source device for an endoscope, and 6 indicates a main body. On the front of this main body 6 is a connector receiver 7.
By detachably inserting the connector 3 of the endoscope 1 into the connector receiver 7, the light guide 4 can be detachably connected to the main body 6. Further, the main body 6 is provided with, for example, a strobe 8 that supplies photographing light along the axial direction of the light guide 4 connected to the main body 6. Further, in a direction perpendicular to the optical path connecting the strobe 8 and the light guide 4, for example, a halogen lamp (corresponding to a light source) 10 is provided for supplying light necessary for collation. And those halogen lamps 1
A reflector 11a is provided at the intersection of the optical paths of the strobe 8 and the strobe 8, and is rotated by a rotary solenoid 11. Based on the rotation of the reflector 11a, under normal conditions, the light beam from the halogen lamp 10 is converted into a light. The light beam from the strobe 8 is irradiated onto the entrance end surface of the light guide 4 to provide illumination light to the endoscope 1, and the light beam from the strobe 8 is irradiated onto the entrance end surface of the light guide 4 when using an endoscope camera (not shown). The endoscope 1 is provided with photographing light. On the optical path 9 connecting the halogen lamp 10 and the light guide 4, an optical fiber 1 having an outer diameter of, for example, 500 μm, which is a light transmission fiber that is the essential part of the present invention, is placed.
2 is provided. The structure around this optical fiber 12 is shown in FIGS. 2a and 2b.

Here, the structure around the optical fiber 12 will be explained. 13 is a fiber holder, and 14 is a light receiving element. Then, the fiber holder 1
3, the optical fiber 12 is held in an upright position relative to the fiber holder 13 so that its tip side is exposed. A light receiving element 14 is provided inside the fiber holder 13 and connected to the rear end of the fiber 12 so that light can be received through the optical fiber 12. The optical fiber 12 held by the fiber holder 13 is installed in the main body 6 so that its tip is located on the optical path 9. Moreover, the tip of the optical fiber 12 is
The end face is roughly polished diagonally so as to face the connector receiver 7, and the notch face 15 is made rough, while the notch face 15 faces the incident end face of the light guide 4. However,
Light from the halogen lamp 10 or strobe 8 can be transmitted from the cutout surface 15 to the light receiving element 14 through the optical fiber 12.
Further, an amplifier 16 and an A/D conversion circuit 17 are sequentially connected to the light receiving element 14 as shown in FIG.

On the other hand, the A/D conversion circuit 17 is further connected to the CPU 19 via the interface 18.
The amount of light obtained by the light receiving element 14 is transferred to the halogen lamp 1.
Automatic light control of 0 (light source), exposure control of endoscope camera (not shown), halogen lamp 10 (light source)
It is used for various information such as the presence or absence of light.

Note that 20 is an electric circuit board provided within the main body 6.

Therefore, when transmitting illumination light to the endoscope 1 using the endoscope light source device 5 configured as described above, first insert the connector 3 of the endoscope 1 into the connector receiver 7 and connect the light guide 4. Connect to the main body 6.

After that, when power is turned on to the light source device 5, the halogen lamp 10 lights up, and the reflecting mirror 11a
The luminous flux of the halogen lamp 10 is irradiated onto the incident end surface of the light guide 4 through the halogen lamp 10 . Thereby, the collected light is sent to the endoscope 1 through the light guide 4. On the other hand, in the optical fiber 12, at the same time as the lighting operation, the halogen lamp 10 passes through the notch surface 15.
The light is guided to the light receiving element 14.

Here, conventionally, the optical fiber 12 for transmitting light to the light-receiving element 14 uses a mirror surface that requires precision processing, making it expensive in terms of cost.
According to the present invention, the cutout surface 15 of the optical fiber 12 is a rough surface, although it may be difficult to effectively take in light. This allows the optical transmission fiber to be made inexpensive, since the tip of the optical fiber 12 can be polished roughly and diagonally, which is the simplest process, as described above. In addition, by making the cutout surface 15 a rough surface, the cutout surface 15 becomes a diffused reflection section, which captures both the direct light from the halogen lamp 10 and the reflected light from the light guide 4, as shown by the arrow. This makes it possible to effectively capture light. Therefore, light from the light source can be taken in inexpensively and effectively.

Note that the accurate light amount signal directly obtained from the halogen lamp 10 that has been photoelectrically converted by the light receiving element 14 is as follows.
The value is digitized by the A/D conversion circuit 17 through the amplifier 16, and the value is read by the CPU 19.

Then, the CPU 19 calculates the amount of emitted light, and uses that information to calculate data for exposure control of an endoscope camera (not shown), control automatic light adjustment, and even detect the presence or absence of light. will be carried out.

〔Effect of the invention〕

As explained above, according to the present invention, the distal end surface of the optical transmission fiber is notched diagonally so as to face the light guide, and the notched surface is made into a rough surface to facilitate processing and to reflect diffused reflection. It becomes possible to take in direct light from the light source and reflected light from the end face of the light guide.

Therefore, it is possible to realize photometry using an optical transmission fiber that is inexpensive and can effectively capture light from a light source.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view showing a schematic configuration of a light source device for an endoscope, and FIGS. 2a and 2b are a front sectional view and a side view showing the structure around the optical transmission fiber. , FIG. 3 is a circuit diagram showing a circuit for processing a signal photoelectrically converted by a light receiving element. 1...Endoscope, 4...Light guide, 6...Main body, 9
...Optical path, 10...Halogen lamp (light source), 12...
Optical fiber (optical transmission fiber), 14... Light receiving element, 15... Notch surface.

Claims (1)

[Claims] 1. A light guide of an endoscope that is detachably connected to the main body, and a light source that is provided on the main body and irradiates a light beam to the incident end face of the light guide are provided, while a light guide is provided on the optical path from the light source to the light guide. In an endoscope light source device, the tip of a transmission fiber is disposed, a light receiving element is connected to the rear end of the optical transmission fiber, and monitor light from the light source is transmitted to the light receiving element. A light source device for an endoscope, characterized in that the distal end face is cut out diagonally so as to face the light guide, and the cutout face is made into a rough surface.