JPH0157765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope light source device, and more particularly to an endoscope light source device that improves the accuracy and reliability of light quantity measurement.

In an endoscope light source device, for example, even if the light source deteriorates, the light emitted from the light source can be stably and reliably delivered to the object to be irradiated, such as the body cavity or the endoscope camera, through the endoscope. It is necessary to obtain and supply the amount of light. Therefore, in light source devices, so-called automatic light control is adopted, which is a structure in which the amount of light from the light source is measured and the output of the light source is controlled by increasing or decreasing the output based on this measurement information. In carrying out this automatic light control, accuracy in the measurement of the amount of light, which is the basis thereof, is required, and loss of the amount of light from the light source is a problem.

Generally, the photometry required for such automatic light control uses light that deviates from the optical path made up of the light source, or uses reflected light that is detected by a light receiving element to avoid the effects of heat. We are measuring the amount of light without However, all of these methods are less accurate because they use so-called leaked light that leaks from the optical path as a photometric medium, and in particular those that use reflected light have the problem of large variations in light intensity and lack of accuracy. .

In view of this point, a technique disclosed in Japanese Unexamined Patent Publication No. 56-6481 has been proposed. In this method, a light receiving element is installed on the optical path of a light source, and from this optical path, light is led out perpendicularly to the optical path through an optical transmission path, and the light is measured by the light receiving element and provided through the optical transmission path. .

However, with this technology, because the necessary light is obtained by separating the light from the optical path, the optical transmission path cannot obtain a sufficient amount of light, which means that the illumination light and photographing light must be attenuated, resulting in large losses. . In addition, since the light receiving element directly receives a large amount of light from the light source, it is subject to thermal damage and has the disadvantage of causing large variations in photometry depending on the lighting time of the light source and the lighting conditions, so it cannot be called an effective method. Nakatsuta.

This invention was made in view of the above-mentioned circumstances, and its purpose is to create a structure in which the optical path of the light source and the light receiving element are connected through an optical transmission fiber, so that the light can be maintained with high precision at any time without any dimming. Another object of the present invention is to provide an endoscope light source device that can perform accurate photometry.

The present invention will be explained below based on a first embodiment shown in the drawings. 1 in Figure 1 indicates an endoscope,
This endoscope 1 is constructed by connecting an insertion section 3 and a light guide cable 4 to an operation section 2 equipped with an eyepiece section 2a. It is now possible to visually see the front of the tip of 3. Note that 2b is a bending operation knob, and 2c is an air/water supply operation valve.
A connector 5a from which a light guide 5 protrudes is provided at the tip of the light guide cable 4, and light is transmitted from the connector 5a through the light guide cable 4, the operation section 2, and the insertion section 3 to the insertion section 3.
The tip can be guided forward.

On the other hand, in the figure, 6 indicates an endoscope light source device, and 7 is a main body of the light source device 6. The front side of the main body 7 is provided with an operation panel 8 equipped with various operation switches 8a. The operation panel 8 is also provided with a connector receiver 9 into which the connector 5a of the endoscope 1 can be inserted and removed. The internal structure of the main body 7 is as shown in FIG. That is, in the figure, 10 is a lamp that is a light source, and this lamp 10 is provided facing the connector receiver 9. Further, the lamp 10 is arranged such that its optical axis coincides with the axis of the light guide 5 inserted into the connector receiver 9, so that the light beam can be focused on the incident end surface of the light guide 5. Therefore, by turning on the lamp 10, light such as collation light or photographing light can be introduced to the front of the distal end of the insertion section 3. Note that 11a is a mounting plate that holds the lamp 10, and 11b is a socket. A dimming system for dimming the light of the lamp 10 is provided in this lamp system. To explain this dimming system, reference numeral 12 in the figure indicates an optical fiber as a light transmission fiber.
This optical fiber 12 has a core 12a made of, for example, a quartz fiber in the center, and a cladding 12b similar to the core 12a is provided on the outer peripheral surface of the core 12a to form a transparent part with a diameter of about 0.45 to 0.6. , the outer peripheral surface of this transparent portion is covered with a protective member 12c. And this optical fiber 12
A portion of the protective member 12c on one end side is removed to form an incident section 13. Further, the end face of the incident portion 13 is cut obliquely at an angle of, for example, 45°, and constitutes a fiber end face 13a that maximizes the amount of incident light. Also, this optical fiber 1
2, the adjustment device 14 adjusts the entrance part 13 of the optical fiber 12 to the optical path 1 of the lamp 10.
0a in a direction perpendicular to the optical path 10a, and the input section 13 is positioned so that the fiber end surface 13a faces the entrance end surface of the light guide 5. Here, the adjustment device 14 will be explained as follows.
This adjustment device 14 has a fixing base 15 on the side wall of the main body 7.
A rack 16 that is movable in a direction perpendicular to the optical path 10a is provided on the fixing base 15, and a fixing tool 17 and a fixing screw 18 are attached to the tip of the rack 16.
The protective member 12c of the optical fiber 12 on the side of the entrance section 13 is fixed at point a, and a pinion 17a for adjustment operation is engaged with the base of the rack 16. Therefore, the optical fiber 12 is
The fiber end face 13a is centered at a predetermined position with respect to the optical axis of the lamp 10 by the adjusting device 14, and the transparent part of the incident part 13 is similarly centered within the luminous flux part of the lamp 10 for adjustment. It's summery. On the other hand, numeral 18 in the figure is a substrate provided within the main body 7. A light receiving element 21 is provided on this substrate 18. In addition, this light receiving element 21
is connected to the power supply circuit 23 of the lamp 10 via an automatic exposure circuit 19 and a dimming circuit 20 provided on the substrate 7. The light receiving section 21a of the light receiving element 21 is connected to the output side end of the optical fiber 12 with a connector 22 for connection, and is capable of sending monitor light transmitted by the optical fiber 12 to the light receiving element 21. Then, the light receiving element 21 outputs an electric signal corresponding to the amount of light and performs photometry, and the automatic exposure circuit 19 calculates the fluctuation of the photometry signal based on the exposure information set in advance, and then the light control circuit 20 By transmitting a control signal output from the automatic exposure circuit 19 to the power supply circuit 23 via the power supply circuit 23, the amount of light from the lamp 10 is controlled to increase or decrease. Note that 24 is a protection tube. Further, FIG. 3 shows the circuit of the photometry system.

Therefore, as for the operation related to automatic light control of the light source device 6 configured in this way, the fiber end face 13a is placed on the optical axis by operating the adjustment device 14 in advance, and the transparent portions of the core 12a and the cladding 12b are It is placed in the luminous flux section of the lamp 10. In this state, connect connector 4 of endoscope 1.
Insert it into the connector receiver 9. Thereby, the light guide 5 of the connector 4 is arranged to face the optical axis of the lamp 10. When the light source device 6 is powered on from this state, the lamp 10 lights up and the collected light is sent to the endoscope 1 through the light guide 5. On the other hand, in the optical fiber 12, at the same time as the lighting operation, light is transmitted (feedback) to the light receiving element 21 through the fiber end face 13a, and photoelectric conversion is performed.

During this lighting operation, when the output of the lamp 10 changes, the fluctuation in the output of the electric signal at the light receiving element 21 due to the change in the amount of light is calculated by the automatic exposure circuit 19, and then the automatic exposure circuit 19 A control signal output from the dimmer is transmitted to the power supply circuit 23 via the dimming circuit 20. In this way, the light intensity of the lamp 10 is controlled to increase or decrease, so-called automatic light control, and an appropriate amount of illuminating light is transmitted to the endoscope 1.
It will be supplied at any time.

Furthermore, when taking pictures by attaching a camera (not shown) to the endoscope 1, an appropriate amount of light corresponding to the required exposure value can be obtained by the above-mentioned photometry and automatic light adjustment according to the photometry. Become.

Therefore, photometry as the amount of light increases or decreases is performed using the light of the lamp 10 itself passing through the optical fiber 12, making it possible to achieve highly accurate and accurate photometry. Moreover, since the optical fiber 12 has an extremely high transmittance, light such as collation light and photographing light is not attenuated. According to experiments, when the diameter of the transparent portion of the optical fiber 12 was about 0.45 to 0.6, the loss was within the range of 1% to 3%, depending on the position of the fiber end face 13a. In addition, by using the thin optical fiber 12 to perform photometry using a small amount of light as a photometric medium, the effect of heat on the light receiving element 21 is eliminated, along with the effect that the light receiving element 21 can be placed at any position by moving it away from the heat source. be done. Furthermore, since the tip of the optical fiber 12 is notched diagonally, the amount of incident light can be stably obtained, and reliability and accuracy, including correction of variations in the installation of the lamp 10, can be significantly improved. Can be done. Furthermore, since the thin optical fiber 12 is used, the space factor can be improved at the same time, and a highly sensitive light receiving element 21 can also be used, which has great effects.

Furthermore, the present invention is not limited to the embodiments described above, but includes, for example, the second embodiment shown in FIG. 4, the third embodiment shown in FIG. 5, and the fourth embodiment shown in FIG. You can do it like this.

That is, in the second embodiment, the optical fiber 12
is mounted obliquely with respect to the optical axis of the lamp 10, and the fiber end face 13a faces the lamp 10. Even in this case, photometry can be performed with high accuracy and reliability as in the above-mentioned embodiment. Can be done.

In the third embodiment, the present invention is applied to a light source consisting of two lamps, in contrast to the above-mentioned light source device that obtains examination light and photographing light using one light source. An optical fiber 12 is attached with one end disposed on a shared optical path 32 of a strobe tube 30 that supplies a strobe light and a lamp 31 that supplies a collation light. Even in this case, the amount of illumination light and photographing light can be measured with high accuracy and reliability by the light receiving element 21 through the optical fiber 12, and an appropriate amount of light can be obtained. Note that 33 is a mirror for switching between the collation light and the photographing light, 34 is a rotary solenoid for driving the mirror 33, and 35 is an adjustment device composed of a holder 35a and an operating screw 35b.

In the fourth embodiment, the present invention is applied to a light source structure in which collation light and photographing light are switched using an aperture blade 36. Specifically, an optical fiber 12 is arranged on an optical path 37, The optical fiber 1 emits light that is appropriately narrowed down by the diaphragm blades 36 during collation.
2 to the light-receiving element and meter the light, and this metering automatically adjusts the amount of light appropriately.Furthermore, it measures the light during shooting when the aperture blades 36 are opened, and adjusts the amount of light appropriately to correspond to the required exposure value. The amount of light is automatically adjusted, and even in this case, the same effect as in the above-mentioned embodiment can be achieved. In addition, 3
8 is a rotary solenoid that drives the aperture blade 36, and 39 is an adjustment device.

As explained above, this invention connects the optical path of a light source and a light receiving element using an optical transmission fiber, transmits the monitor light from the light source through the optical transmission fiber, measures the light at the light receiving element, and adjusts light based on this photometry. Because of this structure, photometry related to dimming directly measures the amount of light from the optical path, making it possible to perform highly precise and accurate photometry.
Furthermore, since the optical transmission fiber has excellent transmittance, the loss of light supplied to the endoscope is extremely small, and problems such as light attenuation do not occur. Furthermore, by using optical transmission fibers, only a small amount of light is required, and the light-receiving element can be placed freely away from the heat source, making it possible to achieve photometry without being affected by heat on the light-receiving element. This allows for greater reliability as well as accuracy. Furthermore, the use of optical fibers has the effect of improving the space factor as well as the ease of installing the light receiving element.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a light source device according to a first embodiment of the present invention together with an endoscope, FIG. 2 is a configuration diagram showing the main parts of the light source device, and FIG. FIG. 4 is a block diagram showing a second embodiment of the invention, FIG. 5 is a perspective view of the third embodiment, and FIG. 6 is a perspective view of the fourth embodiment. It is. 1... Endoscope, 5... Light guide, 6... Light source device, 10, 30, 31... Lamp, strobe tube (light source), 12... Optical fiber (light transmission fiber),
21... Light receiving element.

Claims (1)

[Claims] 1. A light source condenses a luminous flux onto the incident end surface of a light guide of an endoscope and introduces the light into the endoscope, and a light receiving element measures the light from the light source, and based on this photometry, internal In an endoscope light source device that adjusts the amount of light introduced into the endoscope, one end is disposed near the optical path from the light source to the light guide of the endoscope, and the other end is connected to the light receiving element. An endoscope light source device comprising an optical transmission fiber and transmitting monitor light from a light source to a light receiving element through the optical transmission fiber. 2. The endoscope light source device according to claim 1, wherein one end of the optical transmission fiber has an end surface cut out obliquely.