JPH042930B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an endoscopic photographing device, and in particular,
The present invention relates to a photographic device that corrects a reference value for exposure determination according to photographing conditions.

Generally, in photographic devices, it is necessary to correct exposure depending on the sensitivity and type of film. In addition, in an endoscopic photographing device, the size of the image on the film differs depending on the type of endoscope, so it is necessary to correct the exposure. In an endoscope photographing device, these photographing condition signal generating sections are provided not in the camera itself but in the endoscope body or the light source section. Therefore,
Due to poor contact between the camera, the endoscope body, and the light source, these imaging condition information may not be input. As a result, photographs may be taken with inappropriate exposure. Alternatively, even if the signal generating section is provided in the camera itself, there may be cases in which the photographing condition signal is not inputted due to a malfunction or external noise, or even if it is inputted, the exposure cannot be determined. Therefore, as shown in Japanese Utility Model Application No. 53-106216, an automatic light control strobe has been proposed which takes pictures at a predetermined exposure when no exposure conditions are input. However, even in this example, depending on how the exposure conditions are determined, photography may be performed with inappropriate exposure.

SUMMARY OF THE INVENTION An object of the present invention is to provide an endoscopic photographing apparatus that can obtain a reasonable exposure value even when no photographing condition signal is supplied.

Hereinafter, an embodiment of an endoscopic photographing apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram thereof. An image guide 12 and a light guide 14 are provided within the endoscope body 10,
One end portions of the image guide 12 and the light guide 14 extend to a subject 16 as an objective portion. The other end of the image guide 12 reaches the eyepiece and is connected to a camera 18. The light incident on the camera 18 via the image guide 12 passes through the half prism 2.
0, a part of it enters the photodiode 22,
The others are irradiated onto the film 24. The output signal of photodiode 22 is supplied to exposure control circuit 26. The endoscope main body 10 is further provided with a scope type selector 28. The camera 18 is also provided with a film type selector 30. On the other hand, the other end of the light guide 14 reaches the discharge tube 34 inside the light source section 32. A light emission control circuit 36 is connected to the discharge tube 34. In addition, the light source section 3
2 is provided with a light source type selector 38.

FIG. 2 is a diagram of this electrical circuit. Endoscope body 1
Fixed contacts of switches 40, 42, and 44 that operate in conjunction with a scope type selector 28 provided at 0 are connected to a communication interface unit (hereinafter referred to as CIU) 46. CIU 46 is connected to CIU 48 within camera 18. Further, the fixed contacts of the switches 50, 52, and 54 that are linked to the light source type selector 38 provided in the light source section 32 are
It is connected to the CIU 56, and the CIU 56 is connected to the CIU 48. Switch 40, 42, 44, 50, 5
2 and 54, the first movable contact is grounded, and the second movable contact is connected to the power supply terminal Vcc. inside camera 18
CIU 48 is connected to CPU 58. Connected to the CPU 58 are fixed contacts of switches 60 and 62 that are linked to the film type selector 30 and a fixed contact of a switch 64 that is linked to the release. The first movable contacts of the switches 60, 62, and 64 are also grounded,
A second movable contact is connected to the power supply terminal Vcc. CPU5
8 data output ports I0, I1, I2, I3 are D flip-flops 66, 68, 70, respectively.
It is connected to the input end of 72. The output ports of the CPU 58 are D flip-flops 66, 68, 7.
It is connected to the clock end CK of 0.72. Output terminal Q of D flip-flop 66, 68, 70, 72
are connected to one end of the resistors 74, 76, 78, 80, respectively, and the other ends of the resistors 74, 76, 78, 80 are connected in series to the resistors 82, 84, 86, respectively.
88 and the connection point of variable resistor 90.
An output end of variable resistor 90 is connected to a non-inverting input end of operational amplifier 94 via resistor 92 . On the other hand, the output terminal of the variable resistor 96 connected between the positive power supply +V and the negative power supply -V is also connected to the operational amplifier 9 via the resistor 98.
It is connected to the non-inverting input terminal of 4.

A photodiode 22 is connected between the input terminals of the operational amplifier 102, and a capacitor 104 and an analog switch 106 are connected in parallel between the output terminal and the inverting input terminal of the operational amplifier 102. Operational amplifier 1
The output terminal of 02 is connected to the inverting input terminal of operational amplifier 94. The output end of the operational amplifier 94 is connected to the light source section 32
It is connected to the light emission control circuit 36 inside. CPU58
The output port of the analog switch 106 is connected to the gate of the analog switch 106 and the light emission control circuit 36.

Next, the operation of this embodiment will be explained. First, the switches 40, 42, and 44 are switched according to the type of endoscope, and scope type information is supplied to the CPU 58 via the CIUs 46 and 48. Similarly, switches 50, 52, and 54 are switched depending on the type of light source, and light source type information is supplied to the CPU 58 via the CIUs 56 and 48. In the camera 18, film sensitivity information and film type information are sent to the CPU 58 via switches 60 and 62, respectively.
supplied to Note that this information may be set more precisely by increasing the number of switches.
The CPU 58 calculates these shooting condition information and
The calculation results are output from data output ports I0 to I3. Thereafter, the CPU 58 outputs an L level pulse from the output port. As a result, the D flip-flops 66, 68, 70, and 72 store the data at the data output ports I0 to I3, and output the data from the Q output terminal. This output signal is
6,78,80,82,84,86,88,90
The signal is A/D converted and supplied to the non-inverting input terminal of the operational amplifier 94 as a reference signal. After this,
The CPU 58 maintains the output port at H level.

When the shutter is released, the switch 64 is changed, the CPU 58 detects the shutter release, and sets the output port to L level. As a result, the light emission control circuit 36 is activated and the discharge tube 34 emits light, and the analog switch 106 becomes non-conductive. The light emitted from the discharge tube 34 illuminates the object 16 through the light guide 14, and the reflected light from the object enters the photodiode 22 through the image guide 12. Photodiode 22
The output signal of the operational amplifier 102 and the capacitor 10
4, and a signal corresponding to the amount of light received by the photodiode 22 is supplied to the inverting input terminal of the operational amplifier 94. Therefore, when the light reception signal of the photodiode 22 matches the D/A converted signal of the D flip-flop, the output signal of the operational amplifier 94 is inverted. As a result, the light emission control circuit 3
6 stops the discharge tube 34 from emitting light. This results in
Photography is performed with appropriate exposure according to scope type information, light source type information, film sensitivity information, and film type information.

Here, the camera 18, the endoscope main body 10, the light source section 3
If the shutter release is pressed before the shooting condition information is available in the CPU 58 due to poor contact, external noise, or malfunction when connecting to the 2, data out of the normal range will be output from the data output ports I0 to I3. is output. In response to the out-of-normal range from output ports I0 to I3, CPU 58 keeps output port STB at H level, thereby not performing memory update operations in D flip-flops 66, 68, 70, and 72. Similarly, if an abnormal value is input even though the shooting condition information is input, the data output ports I0 to I3 will be out of the normal range. The previous memory value is maintained without updating the memory.
That is, the CPU 58 calculates a reference signal for exposure based on the input photographing condition information, and causes the D flip-flop as a storage means to perform a storage operation only when the reference signal as a result of this calculation is within a normal range. It controls the D flip-flop. Therefore, the D flip-flop stores and updates only the exposure reference signal within the normal range, and even if an abnormal exposure reference signal is calculated due to an abnormality in the connection of the equipment, that reference signal will not be stored. In this example, for example, the CPU
Even if the exposure reference signal cannot output a normal calculation result, the exposure control is performed using the previously stored exposure reference signal, so exposure control based on an abnormal exposure reference signal can be avoided. In the case of endoscopic photography, the photographing condition information does not change during the photographing process, so even if the previous exposure reference signal is used, there is little exposure error.

Note that the present invention is not limited to the above-described embodiments, and it is possible to use a sample-and-hold circuit in place of the D flip-flop, or to provide an exposure control circuit in the endoscope body or light source section. Further, a display section or an alarm section may be provided that issues an alarm when the CPU 58 detects an abnormality in information input.

As described above, according to the present invention, it is possible to provide an endoscopic photographing apparatus that can perform appropriate exposure control even when no photographing condition information is input.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of an endoscopic photographing apparatus according to the present invention, and FIG. 2 is an electrical circuit diagram thereof. 22...Photodiode, 36...Light emission control circuit, 58...CPU, 66, 68, 70, 72
...D flip-flop, 94,102 ~ operational amplifier.

Claims (1)

[Scope of Claims] 1. An endoscope comprising: a light source section; an endoscope body that illuminates a subject with light emitted from the light source section to create a subject image; and a camera attached to the endoscope body. In a photographic apparatus, a photographing condition information generating section generates photographing condition information such as film sensitivity information, a calculating means receives this photographing condition information and calculates an exposure reference signal in accordance with the photographing condition information, and a calculating means calculates an exposure reference signal according to the photographing condition information; storage means for storing; and control for causing the storage means to maintain the previous stored value and prevent a new exposure reference signal from being stored when the exposure reference signal obtained by the calculation means is outside a predetermined range; means, a light receiving means for generating an electrical signal according to the reflected light from the subject, and a comparing means for comparing the electrical signal from the light receiving means and the output signal from the storage means and outputting an exposure stop signal. An endoscopic photographing device characterized by: