JPS6336771B2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) This invention eliminates mechanical and electrical contacts between a camera, an endoscope, and a light source device in an automatic exposure signal circuit, etc. The present invention relates to an endoscopic photographing device.

(Prior Art) Generally, in an endoscope photography device, a camera and a light source of an endoscope are electrically coupled. This combination is used to synchronize the flash light for photography.
and automatic exposure control. This coupling is typically achieved through a plurality of mechanical and electrical contacts provided in the endoscope eyepiece and connector. All of these contacts are exposed on the outer surface. Therefore, poor contact was likely to occur due to dirt, oxidation, corrosion, etc. In order to avoid this drawback, the contacts may have a waterproof structure. However, waterproof electrical contacts have a complicated structure and do not solve the essential problem.

(Problems to be Solved by the Invention) As a technique for solving the above-mentioned problem, there is a technique disclosed, for example, in Japanese Patent Application Laid-open No. 38322/1983. Here, the camera is provided with a light emitting element, and the light source section is provided with a light receiving element. Light emitted from the light emitting element is transmitted to the light receiving element via a signal light guide within the endoscope. In the device disclosed herein, light emitted from a light emitting element is used as a synchronization signal for the flash light. Therefore, mechanical electrical contacts for the synchronization are not required. However, this device cannot be applied when automatic exposure control is performed on the light source side.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an endoscopic photographing device that can combine a camera and an endoscope light source so as to perform automatic exposure control without using mechanical electrical contacts. purpose.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the endoscopic photography device according to the present invention wirelessly connects the camera and light source device for automatic exposure control. ing.

(Function) With the wireless coupling described above, a synchronization signal linked to the release and a brightness signal including exposure information are sent from the camera to the light source device without going through any mechanical or electrical contacts. Then, the light source device uses the synchronization signal as a control start timing and uses the brightness signal to perform automatic exposure control to obtain a predetermined amount of photographing light.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention. Endoscope 10 has an image guide fiber 12 and a light guide fiber 14 for transmitting optical images. Light receiving end 14 of fiber 14
₁ is provided with light from a light source, that is, a lamp 18, via a condensing lens 16. A concave mirror 19 is arranged behind the lamp 18 to improve illumination efficiency. The light given to the light receiving end 14 ₁ passes through the fiber 14 to the light emitting end 1 on the tip component 10 ₁ side.
4 Released from ₂ . An objective lens 20 of an observation optical system is provided within the tip component 10 ₁ . The optical image of the object captured by the objective lens 20 is transferred to the endoscope 10 via the image guide fiber 12.
is guided to the eyepiece lens 22 of. Eyepiece lens 22
The optical image that has passed through is incident on the movable mirror 26 via the half prism 24. When photography is not being performed, the optical image incident on the movable mirror 26 is transmitted to the outside of the camera 34 attached to the endoscope 10 via the condenser lens 28, pentaprism 30, and camera eyepiece 32. derived. On the other hand, when photographing is performed, the movable mirror 26 is moved to the position indicated by the broken line in the figure. Then,
The optical image passing through the half prism 24 is transmitted to a film 38 via a shutter 36.

A portion of the optical image is dispersed to the right side of the figure by the half prism 24. half prism 24
A light-receiving element, that is, a photodiode 40 is disposed on the right end surface side. A cadmium sulfide (CdS) cell or a solar cell can also be used as the light receiving element. The photodiode 40 generates a brightness signal having a magnitude corresponding to the brightness of the optical image passing through the half prism 24. This brightness signal is input to the transmitter 42. The transmitter 42 includes a synchronization signal that provides control timing for the lamp 18 and a circuit (not shown) that generates a transmission signal corresponding to the brightness signal. The synchronization signal included in this transmission signal is generated in synchronization with the release of the camera, and determines the start timing of automatic exposure control. Further, the brightness signal included in the transmission signal includes exposure information for automatic exposure control, and is transmitted after the synchronization signal is transmitted. This transmission signal is emitted to the outside via the antenna 44.
A power source 46 is coupled to transmitter 42 . The transmitted signal emitted from antenna 44 is captured by antenna 48. The transmitted signal captured by antenna 48 is input to receiver 50. Then, the receiver 50 demodulates a feedback signal corresponding to the transmitted signal.

The feedback signal demodulated by the receiver 50 is input to the light source control device 52. The demodulated feedback signal includes the synchronization signal and a brightness signal following the synchronization signal. This control device 5
Reference numeral 2 provides a control signal corresponding to the brightness signal to the lamp 18, which is a light source, after detecting the synchronization signal in the feedback signal, and can be constructed using conventional technology. Light receiving end 14 of fiber 14 from lamp 18
The amount of light supplied to _{the lamp 1} can be controlled by adjusting the power supplied to the lamp 18 based on the control signal or by changing the number of times the lamp 18 blinks. The lamp 18, the receiver 50, and the light source control device 52 constitute a light source device 54 .

The configuration shown in FIG. 1 forms an automatic control system in which a closed loop includes an object (not shown), such as the wall of the large intestine, which exists ahead of the distal end component ₁₀₁ . That is, when the subject is dark, the optical image dispersed to the photodiode 40 side is also dark. Then, since the brightness signal output from the photodiode 40 is small, the modulation of the transmitter 42 is shallow. Then, the feedback signal demodulated by the receiver 50 has a low level. When the level of this feedback signal is low, the light source control device 52 controls the lamp 18
The voltage or current supplied to the lamp 18 is increased, or the number of flashes of the lamp 18 is increased. Then, the amount of light given to the light guide fiber 14 increases, making the subject brighter. Through such an automatic control operation, the amount of light of the optical image derived from the image guide fiber 12 can be automatically controlled to a desired amount of light.

The photographic device of FIG. 1 is used as follows. Initially, the movable mirror 26 is set at the position indicated by the solid line in the figure until the photographing location is found.
When the photographing location is found, a release button (not shown) is pressed. Then, a synchronizing signal is transmitted from the transmitter 42, the movable mirror 26 is moved to the position shown by the broken line, the shutter 36 is opened, and the film 38 is exposed. In parallel with this operation, automatic exposure control is performed. That is, film 38
A brightness signal corresponding to the brightness of the optical image exposing the image is detected by photodiode 40.
This brightness signal is transmitted to a transmitter 42 and a receiver 50.
is transmitted to the light source control device 52 via. When the synchronization signal is transmitted to the control device 52, the lamp 18 is flashed. Next, lamp 18
is controlled so that the amount of light of the optical image exposing the film 38 is an appropriate amount. When the exposure amount (photographing light amount) for the film 38 reaches a proper value, the lamp 18 is temporarily turned off or the shutter 36 is closed, and one photographing session is completed. At the end of this photographing, the movable mirror 26 has returned to the position indicated by the solid line in the figure.

FIG. 2 shows a modification of FIG. 1. In FIG. 1, automatic exposure control is performed by changing the power supplied to the lamp 18. In FIG. 2, instead of controlling the lamp 18, a diaphragm device 15 is provided between the light receiving end ₁₄₁ of the fiber 14 and the condenser lens 16. The aperture state of this aperture device 15 is controlled by an aperture control device 53. That is,
When the subject is dark, the brightness signal derived from the photodiode 40 is at a small level. This small level brightness signal is transmitted to the transmitter 42 and the receiver 5.
0 to the aperture control device 53. Then, the aperture state of the aperture 15 is changed so that the level of the brightness signal increases.

〔Effect of the invention〕

As described above, the photographing device according to the present invention does not require electrical contacts exposed on the outer surface of the endoscope. This not only makes it easier to make the endoscope waterproof, but also prevents the electrical contacts from getting dirty.
No contact failures due to oxidation, corrosion, etc. occur.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an endoscopic photographing apparatus according to the present invention, and FIG. 2 is a block diagram showing a modification of FIG. 1. DESCRIPTION OF SYMBOLS 10... Endoscope, 10 ₁ ... Tip component, 12... Image guide fiber, 14... Light guide.
Fiber, 14 ₁ ... Light receiving end, 14 ₂ ... Light emitting end, 15
...Aperture device, 16...Condensing lens, 18...Lamp (light source), 19...Concave mirror, 20...Objective lens, 2
2, 32...eyepiece, 24...half prism,
26...Movable mirror, 28...Condenser lens, 3
0...Penta prism, 34...Camera, 36...Shutter, 38...Film, 40...Photodiode (light receiving element), 42...Transmitter, 44, 48...Antenna, 46...Power source, 50...Receiver, 52...Light source control Device, 53...Aperture control device, 54 ...Light source device.

Claims (1)

[Scope of Claims] 1. An endoscope having an image guide fiber and a light guide fiber, a light source device having a light source that provides light to the light guide fiber, and an optical image derived from the image guide fiber. and a camera mounted on the optical path of the optical image, the camera comprising: a light receiving element that is provided on the optical path of the optical image and generates a brightness signal corresponding to the brightness of the optical image; a circuit that generates a synchronization signal that provides a timing for controlling the light source to the photographing light intensity in conjunction with the brightness signal; a circuit that generates a transmission signal corresponding to the synchronization signal and the brightness signal; a transmitter that wirelessly transmits a portion of the brightness signal in the photographing light amount after wirelessly transmitting a portion of the image capturing light, the light source device receiving the wireless transmission signal and transmitting a feedback signal including the brightness signal and the synchronization signal. a receiver that generates a signal; starts controlling the light source based on the synchronization signal included in the feedback signal, and is applied from the light source to the light guide fiber based on the brightness signal included in the feedback signal; An endoscopic photographing device comprising: a light source control device that controls a light amount to the photographing light amount. 2. The light source includes a lamp, and an aperture device between the lamp and the light guide fiber that controls the amount of light given to the light guide fiber, and the aperture device includes an aperture control device that controls the aperture state of the aperture device. 2. The endoscopic photographing apparatus according to claim 1, wherein the aperture control device is controlled by the receiver so as to obtain the photographing light quantity.