JPH0444247B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscopic photographing device for photographing the inside of a body cavity through an endoscope.

Generally, in an endoscope photography device, the illumination angle from the illumination window of the endoscope is usually constant. When photographing the interior of a body cavity with many lumens and slopes with such a device, the distant view will be extremely dark, while the close-up area will be significantly overexposed.
The properly exposed area was a small area at a medium distance, making diagnosis by photography difficult. It is also conceivable to manually change the illumination angle while actually observing the subject, but manual operation is complicated and impractical.

The present invention has been made focusing on the above circumstances,
The purpose of this is to automatically change the light distribution characteristics according to the condition of the subject, so that even if it is difficult to obtain an appropriate exposure because the subject is in a cavity or on a slope, the appropriate exposure can be obtained across the entire screen. An object of the present invention is to provide an endoscope photography device.

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 6.

Reference numeral 1 in FIG. 1 is an endoscope, and the endoscope 1 includes an operating section 2, an insertion section 3, and a light guide cable 4. As shown in FIG. An objective lens 5 for a viewing window is provided at the distal end of the insertion section 3. An image guide 6 made of a bundle of optical fibers is inserted into the operating section 2 and the insertion section 3 over both of them. The tip of the image guide 6 is optically connected to the objective lens 5. Further, the operation section 2 is provided with an eyepiece section 8 having eyepiece lenses 7, 7, and a camera 9 is detachably attached to the eyepiece section 8. cable 4
A connector 12 for connecting to the illumination light source device 11 is attached to the extending end of the illumination light source device 11 . Further, a light guide 13 made of an optical fiber bundle is inserted into the insertion section 3, the operation section 2, and the cable 4 and extends over each member thereof. The tip of this light guide 13 is closely opposed to the illumination window 14 formed at the tip (output end) of the insertion section 3, and the base end (incidence end) is inserted into the guide tube 12a provided in the connector 12. is maintained. Therefore, when the connector 12 is attached to the light source device 11 in the state shown in FIG.
It is arranged to be located on the optical axis l of 16. Further, this light source 16 is attached to the tip of a holding lever 17 by a hook 18 and pressing springs 19, 19, and a connector 21 of this light source 16 is electrically connected to a power source 22 via cords 23, 23. has been done. The base end of the holding lever 17 is attached and fixed to a drive shaft 25 of a rotational drive device 24. This rotary drive device 24 rotates the holding lever 17 to constitute a position changing mechanism that rotates the direction of the optical axis l of the light source 16 about the center of the incident end surface 15 of the light guide 13. The rotational drive device 24 includes a motor 26 and a gearbox 27, and the rotation of the motor 26 is controlled by the gearbox 2.
7, the speed is decelerated and transmitted to the drive shaft 25. Note that the amount of operation of the motor 26 and the direction of its rotation are automatically controlled by a control circuit 28 as a light distribution characteristic changing means, which will be described later.

The entrance end surface 15 of the light guide 13 and the light source 1
A shutter 29 that can be selectively opened and closed is inserted between the shutter 6 and the shutter 6. This shutter 29 is driven by a solenoid 30 which is controlled as will be described later.

On the other hand, a beam splitter 31 is provided in the eyepiece section 8 of the endoscope 1, located between the output end surface 32 of the image guide 6 and the eyepiece lenses 7, 7.
This beam splitter 31 splits a part of the light emitted from the output end surface 32 of the image guide 6 and guides it to the side. four first light-receiving elements 33 and four second light-receiving elements 3 corresponding to the peripheral part of the image as a part other than the center part.
The detecting section 35 is configured by installing 4.... The light receiving elements 33, 34, . . . are arranged as shown in FIG. 4 with respect to the image area 36 of the subject.

Note that a mirror shutter 37 is provided inside the camera 9.
and a synchro switch 38.
A mirror shutter 37 is arranged in front of the film 39 and is opened during exposure.

Next, the electric circuit will be explained with reference to FIG.
The output terminals of each of the light receiving elements 33, 34... of the detection section 35 are connected to the first and second current amplification circuits 4, respectively.
1, 42... In FIG. 2, only two elements corresponding to the second light receiving elements 34 are shown, and the others are omitted. The output terminals of the second current amplifying circuits 42 corresponding to the second light receiving elements 34 are connected to the adding circuit 43. This adder circuit 43 is configured to add the outputs of the respective current amplifier circuits 42 and at the same time invert the polarity thereof.
The output end of the first current amplification circuit 41 corresponding to the first light receiving element 33 is connected to the same difference amplification circuit 44 as the output end of the addition circuit 43, so that each output value is subjected to subtraction processing. ing. Furthermore, the output terminal of the difference amplification circuit 44 is connected to a third current amplification circuit 45, and this third current amplification circuit 45
is connected to the motor 26 of the rotary drive device 24, and is adapted to control the rotation amount and rotation direction of the motor 26. In this way, a control circuit (means) 4 that processes each information of the photometric signal obtained by the measuring means consisting of each light receiving element 33, 34...
6 is composed.

Further, in this embodiment, exposure calculation is performed using at least part of the information obtained by the measurement means.
That is, for example, the output terminal of the first current amplifying circuit 41 corresponding to the first light receiving element 33 is connected to an integrating circuit 47 for controlling exposure.
7 is connected to a comparator 48. In addition, 49
is the reference power supply. Further, the switch 51 of the integrating circuit 47 is operated by a switch driving circuit 52. The switch drive circuit 52 is connected to the synchro switch 38 described above, and when the synchro switch 38 is closed with the release operation, the switch drive circuit 52 is activated and the switch 51 is opened. There is. The output end of the comparator 48 is connected to a solenoid drive circuit 53 which excites the solenoid 30 and closes the shutter 29.

Next, the operation of the endoscope photography device having the above configuration will be explained.

First, assume that the subject is in a tubular state as shown in FIGS. 3 and 5. If the angle between the optical axis l of the light source 16 of the illumination light source device 11 and the central axis of the incident end surface 15 of the light guide 13 is θ, then the light source 1
The light component of the light No. 6 that is incident obliquely increases. Therefore, the spread angle of the light emitted from the output end of the light guide 13 is large, resulting in a light distribution state as shown in FIG. 3. Therefore, only the peripheral wall within the lumen is brightly illuminated, but the central portion becomes extremely dark. As shown in FIG. 4, the photographed image is very dark in the center, that is, in the far distance, and has a wide range, while the middle distance is somewhat dark, and the peripheral near distance is conversely bright. In other words, only a narrow area around the area is bright. The reason for this is that the light emitted from the light guide 13 has a large spread angle, and therefore only the peripheral areas at a short distance are illuminated intensively. If a photograph is taken in this state, the surrounding areas will be overexposed and the other areas will be underexposed, making it impossible to obtain proper exposure as a whole, making accurate diagnosis difficult.

By the way, in this case, the present invention automatically operates as follows. That is, in the detection unit 35, the amount of light that enters the first light receiving element 33 is small, whereas the amount of light that enters the second light receiving elements 34 is large. Therefore, the first current amplification circuit 41
The output currents of the second current amplifier circuits 42, . Note that when the entire area of the image to be photographed has the same illuminance, the sum of the output current value of the first current amplification circuit 41 and the output current of the second current amplification circuit 42 is set to be equal. There is.

Therefore, when the output of the first current amplifier circuit 41 and the output of the adder circuit 43 are subtracted by the difference amplifier 44, the output of the adder circuit 43 is larger than the output of the first current amplifier circuit 41. 44 becomes negative and is amplified by the third current amplification circuit 45 to drive the motor 26 of the rotary drive device 24 with a negative voltage. When the motor 26 is driven by a negative voltage, the holding lever 17 is rotated via the gear box 27 and the drive shaft 25 so as to reduce θ. That is, the light source 16 rotates toward the state shown by the solid line in FIG. When the angle θ between the center of the light guide 13 and the center of the light guide 13 becomes smaller, the component of the light that enters obliquely decreases, so the spread angle of the light that comes out from the light guide 13 becomes smaller. In other words, the state approaches the state shown in FIG. Therefore, the distant parts of the lumen can be sufficiently illuminated, so the image of the subject has fewer dark areas and the entire image has uniform brightness, as shown in Figure 5. .

This operation is then performed automatically. Therefore, when taking a photo, press the release button of the camera 9, the mirror shutter 37 will rise, and the film 3
9 is exposed. At the same time, the synchro switch 38 is closed, the switch drive circuit 52 is activated, the switch 51 is opened, and the output signal of the first current amplification circuit is integrated by the integration circuit 47, and when it reaches a predetermined level, the reference power supply The signal compared to the voltage at 49 inverts the output of comparator 48;
The solenoid 30 of the shutter 29 is energized via the solenoid drive circuit 53, and the shutter 29 is closed. Therefore, the light from the light source 16 is transmitted to the light guide 1.
3, and the exposure operation is ended.

On the other hand, when the light source 16 is at the position shown by the solid line in FIG. 2, if the subject is flat, the situation described above will be reversed, and the light source 16 will automatically operate as shown in FIGS. 3 and 4. The state shown in is realized. Therefore, even in this case, photography can be performed with uniform illumination.

Note that the detection unit 35 in the above embodiment may be provided on the endoscope 1 side together with the beam splitter 31, but may also be provided on the camera 9 side.
Alternatively, the control circuit 46 may be installed on the camera 9 side, and the motor 26 may be driven by a signal from the camera 9.

FIG. 7 shows another embodiment of the invention. In this embodiment, the entrance end surface 1 of the light guide 13 is
The spreading angle of the light emitted from the light guide 13 is changed by selectively blocking a part of the light from the illumination light source 16 directed toward the light guide 13 by a shielding member. In other words, the light shielding plate 61 is installed at the center of the irradiation range of the light source 16, and this light shielding plate 6
1 shaft 62 is connected to gear box 6 by motor 63.
Rotate through 4. In the case of a tubular object, the direction of the light shielding plate 61 is set to the light source 1.
If you align it with the optical axis of No. 6, you can brightly illuminate areas far from the center. Furthermore, in the case of a flat object, if the light shielding plate 61 is rotated so that its surface direction intersects with the optical axis direction of the light source 16, the amount of light in the center portion is reduced and the entire object can be illuminated uniformly.

FIG. 8 shows still another embodiment of the present invention, in which a diaphragm 65 is provided to selectively cut off light from the peripheral portion of the irradiation range of the light source 16. This throttle 65 is controlled by a gear box 67 by a motor 66.
and is opened and closed via a drive shaft 68.
In the case of a tubular object, surrounding light is cut out using an aperture. Furthermore, in the case of a flat subject, peripheral light is allowed to enter without being cut off. In this way, the same effects as in the above embodiment can be obtained.

Furthermore, in the present invention, the methods shown in FIGS. 7 and 8 may be combined.

Further, as a light receiving element used for exposure calculation of the camera 1, any or all of the second light receiving elements 34 are used, and all the light receiving elements 33,
34... may also be used.

As described above, according to the present invention, even if the subject is in a significantly different situation, such as a lumen, a slope, or a directly facing flat surface, the situation is detected and the light distribution characteristics are automatically changed to have an appropriate light distribution characteristic. Therefore, photography can be easily and quickly done without requiring any special operations.
Furthermore, since the obtained exposure of the entire photographic screen is always obtained in an appropriate state without error, diagnosis can be easily and accurately performed.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the general configuration of an endoscope photographing device showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the schematic configuration centered on the electric circuit of the same embodiment. , FIG. 3 is an explanatory diagram of one light distribution state when illuminating a luminal object, and FIG.
A diagram showing the illuminance distribution of the image in the state shown in the figure, Figure 5 is an explanatory diagram of the appropriate light distribution state when illuminating a tubular object, and Figure 6 is the illuminance distribution of the image in the state shown in Figure 5. , FIG. 7, and FIG. 8 are explanatory diagrams of the configuration of means for converting light distribution characteristics showing other embodiments, respectively. 1... Endoscope, 6... Image guide, 9...
Camera, 11...Light source device for illumination, 13...Light guide, 14...Illumination window, 15...Incidence end surface,
16...Light source, 24...Rotary drive device, 28...
Control circuit, 31... Beam splitter, 33...
First light receiving element, 34... Second light receiving element, 35
...detection section, 41 ... current amplification circuit, 42 ... current amplification circuit, 43 ... addition circuit, 44 ... difference amplification circuit, 45 ... current amplification circuit, 46 ... control circuit, 47 ... integration circuit .

Claims (1)

[Scope of Claims] 1. An illumination light source, a light guide that guides the light of the illumination light source toward the subject, and a light distribution characteristic changing mechanism that changes the spread angle of the illumination light emitted from the light guide toward the subject. a driving means for driving the light distribution characteristic changing mechanism; an observation optical system for observing the image of the subject; and a system for receiving the subject image from the observation optical system and distinguishing between the center and peripheral parts of the image. The brightness distribution of the subject image is determined by comparing the photometric signal of the center area and the photometric signal of the peripheral area obtained by this photometric device. If the determination result is that the center is brighter than the periphery, the spread angle of the illumination light is widened, and if the center is darker than the periphery, the spread angle of the illumination light is narrowed. An endoscope photography device comprising: a control means for driving the drive mechanism to operate the light distribution characteristic changing mechanism. 2. The light distribution characteristic changing mechanism is a position changing mechanism that changes the direction of the optical axis of the illumination light source with respect to the incident end surface of the light guide, with the incident end surface as the center. The described endoscope photography device. 3. The light distribution characteristic changing mechanism is a means for selectively blocking a part of the light from the illumination light source directed toward the incident end surface of the light guide with a blocking member, The described endoscope photography device.