Source: http://www.google.com/patents/US4959710?dq=U.S.+Patent+No.+4,528,643)
Timestamp: 2014-03-16 00:51:27
Document Index: 41041428

Matched Legal Cases: ['art 11', 'art 11', 'art 54', 'arts 52', 'art 11', 'art 7', 'art 54', 'art 58', 'art 58', 'art 58', 'art 11', 'art 11', 'art 7', 'art 11', 'art 11', 'art 11', 'art 144', 'art 148', 'art 11', 'art 11', 'art 11']

Patent US4959710 - Electronic endoscope whereby the position of the insertable part can be ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsAn electronic endoscope apparatus whereby the position of the tip part of an insertable part inserted into a body cavity is confirmed from outside the body with the transmission out of the body from within the body cavity of a light emitted from an illuminating window provided in the tip part. It comprises...http://www.google.com/patents/US4959710?utm_source=gb-gplus-sharePatent US4959710 - Electronic endoscope whereby the position of the insertable part can be known by a transmitted light outside a bodyAdvanced Patent SearchPublication numberUS4959710 APublication typeGrantApplication numberUS 07/311,541Publication dateSep 25, 1990Filing dateFeb 16, 1989Priority dateMar 1, 1988Fee statusPaidPublication number07311541, 311541, US 4959710 A, US 4959710A, US-A-4959710, US4959710 A, US4959710AInventorsJun Hasegawa, Masahide Kanno, Takehiro Nakagawa, Katsuyuki Saito, Katsuyoshi Sasagawa, Masahiko Sasaki, Akinobu Uchikubo, Masao Uehara, Shinji YamashitaOriginal AssigneeOlympus Optical Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (5), Referenced by (23), Classifications (16), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetElectronic endoscope whereby the position of the insertable part can be known by a transmitted light outside a bodyUS 4959710 AAbstract An electronic endoscope apparatus whereby the position of the tip part of an insertable part inserted into a body cavity is confirmed from outside the body with the transmission out of the body from within the body cavity of a light emitted from an illuminating window provided in the tip part. It comprises an imaging apparatus for creating an image of an inspected part obtained from an observing window provided in the tip part of the insertable part and for converting this image to an electric signal and outputting it, an illuminating apparatus for feeding an illuminating light to the imaging apparatus and for adjusting the brightness of the illuminating light when a confirming signal directing to confirm the position of the tip part of the insertable part is input, a signal processing apparatus for processing the electric signal obtained from the imaging apparatus, outputting a video signal which is a normal observing picture image signal of a moving picture in case the confirming signal is not input and outputting a video signal which is a picture image signal different from the ordinary observing picture image signal in case the confirming signal is input, and a displaying apparatus for receiving the video signal output by the signal processing apparatus and displaying the picture image of the inspected part.
During the inserting operation, in order to confirm the position of the tip part 11, the operator switches on the body outside light observing switch 47 provided in the light source apparatus 3. By this on-signal, the filter moving motor 31 is started to drive and the rotary color filter 24 begins to retreat from the light path as in (c) in FIG. 3. In this moving period T.sub.1, the illuminating light is indefinite. At the time point when the movement of the rotary color filter 24 is completed, the illuminating light will become a white light of an increased brightness and the position of the tip part 11 will be easily confirmed by the light transmitted from within the body. By on-signal of the body outside light observing switch 47, the input terminal 48b and 49b sides of the switches 48 and 49 of two inputs and one output are selected by the control circuit 46.
Next, after the period T.sub.4 when the confirmation of the tip position by the body outside transmitted light ends, the operator again pushes the body outside light observing switch 47 to be off. By this off-signal, the rotary color filter having retreated out of the light path will begin to move into the light path. When the movement ends after the moving period T.sub.3 and the illuminating light changes to R (red), G (green) and B (blue) separated from the white light, the input terminal 48a and 49b sides of the switches 48 and 49 will be selected by the control circuit 46. The observed image illuminated by the respective color lights of R (red), G (green) and B (blue) is formed on the solid state imaging device 34, is converted to an electric signal and is processed to produce color signals R, G and B which are analogized by the D/A converters 44 and are output to the monitor 6 through the switching switches 48 and 49 of two inputs and one output. The monitor 6 displays on a picture surface a color moving picture which is an ordinary observing picture image.
As mentioned above, in this embodiment, as the picture image signal input into the monitor 6 by the switches 48 and 49 of two inputs and one output is made a G monochrome during the period T.sub.4 which is the total of the periods T.sub.1 and T.sub.3 when the rotary color filter 24 moves and the period T.sub.2 when the rotary color filter 24 is fixed out of the light path, in case the color signal is indefinite due to the illuminating light when the rotary color filter 24 is moved and in case the illuminating light becomes white after the rotary color filter 24 is retreated, a picture image having no color smear by the movement of the object within the body and easy to see will be able to be provided.
In FIG. 5, a memory part 54 consisting of two frame memory parts 52 and 53 is connected to the rear of the multiplexer 42. This one frame memory 52 is provided with an R.sub.1 frame memory 52R, G.sub.1 frame memory 52G and B.sub.1 and B.sub.1 frame memory 52B into which color signals of R, G and B are to be respectively written in. The other frame memory 53 is provided with an R2 frame memory 53R, G2 frame memory 53G and B2 frame memory 53B.
When the body outside light observing switch 47 is switched on in order to confirm the position of the tip part 11 of the insertable part 7, this on-signal will be input into the filter moving motor 31 (FIG. 2), control circuit 46 and synchronizing circuit 57. By this on-signal, the filter moving motor 31 will move and the illuminating light will become white. Just after this on-signal, as synchronized with the rise or fall of the frame memory switching signal, the black and white/color display switching signal shown in FIG. 6(f) is output to the switches 48 and 49 of two inputs and one output. By this black and white/color display switching signal, the switch 48 selects the input terminal 48b and the switch 49 selects the input terminal 49b and, in the state in FIG. 5, the color signal of the G.sub.2, frame memory 53G is output to the monitor 6. In the monitor 6, as the input signal is only the G signal, a moving picture of a black and white picture image by the G monochrome different from the ordinary observing picture image is stably displayed and no color smear is produced.
Digital-converted R, G and B color signals are sequentially transmitted from the A/D converter 41. For example, if the color signal R1 is transmitted, the control circuit 46 will output a writing signal to the frame memory 54a and will write the color signal R.sub.1 into the frame memory 54. At the same time, the control circuit 46 outputs reading signals to the other frame memories 54b, 54c and 54d and read color signals R.sub.0, G.sub.0 and B.sub. respectively out of these memories 54b, 54c and 54d. By the way, in FIG. 8(b), the circle ( ○ ) mark represents that the frame memory 54 is in a reading state.
When a color signal G.sub.1 is then transmitted from the A/D converter 41, the control circuit 46 will output a writing signal to the frame memory 54b and will write the color signal G.sub.1 into the frame memory 54b. At the same time, the control circuit 46 outputs reading signals respectively to the frame memories 54a, 54c and 54d and reads color signals R.sub.1, G.sub. and B.sub. respectively out of these frame memories 54a, 54c and 54d.
When a color signal B.sub.1 is then transmitted from the A/D converter 41, the control circuit 46 will output a writing signal to the frame memory 54 and will write a color signal B.sub.1 into the frame memory 54c. At the same time, the control circuit 46 outputs reading signals to the other frame memories 54a, 54b and 54d and reads color signals R.sub.1, G.sub.1 and B.sub. respectively out of these frame memories 54a, 54b and 54d.
The control circuit 46 outputs writing signals and reading signals to the memory part 54 as mentioned above and, for example, when the writing of the color signal R.sub.1 into the frame memory 54a ends, as in FIG. 6(c), a one-frame memory writing-in end signal will be output to the synchronizing circuit 5 from the control circuit 46.
From the γ-correcting circuit 39, the γ-corrected video signals are input into the switches 121, 122 and 123 and A/D converter 41 by sequential signals of R, G and B as in FIG. 10(b). Here, for example, when the color signal R.sub.1 is output from the γ-correcting circuit 39, this color signal R.sub.1 will be input into the A/D converter 41 and the input terminals 121a, 122b and 123a of the switches 121, 122 and 123. In the A/D converter 41, the color signal R.sub.1 is digitalized and is output to the memory part 58 in which a writing signal is input into the R frame memory 58a from the control circuit 46 and the color signal R.sub.1 is written into the R frame memory 58a by this writing signal. Simultaneously with outputting the writing signal, the control circuit 46 outputs a reading signal to the G frame memory 58g and B frame memory 58c and reads color signals G.sub. and B.sub. out of the G frame memory 58b and B frame memory 58c.
On the other hand, the color signal R.sub.1 written into the R frame memory 58a is simultaneously input into the input terminals 121a, 122a and 123a of the switches 122, 123 and 123 into which the control circuit 46 inputs a control signal to control the switching. The control circuit 46 outputs a control signal to receive the signal from the γ-correcting circuit 39 in the switches 121, 122 and 123 connected to the frame memory to which the writing signal is output and not to receive the signals from the frame memories 58a, 58b and 58c in the switches 121, 122 and 123 connected to the frame memory to which the reading signal is output. That is to say, in the state in FIG. 9, as the writing is made into the R frame memory 58a, the switch 121 connected to this R frame memory 58a is switched to the input terminal 121a side and the switches 122 and 123 connected to the G frame memory 58b and B frame memory 58c out of which the reading is being made are switched to the input terminal 122b and 123b sides.
The color signal R.sub.1 which is the color signal being thus written in and the color signals G.sub.0 and B.sub.0 read out of the G frame memory 58b and B frame memory 58c are output to the monitor 6.
Then, the color signal G.sub.1 is output out of the γ-correcting circuit 39 and is output to the memory part 58 through the A/D converter 41. In this memory part 58, the writing signal is output to the G frame memory 58 from the control circuit 46 and the color signal G1 is written into the G frame memory 58b. In the other frame memories 58a and 58c, the reading signals from the control circuit 46a are input and the color signals R.sub.1 and B.sub.0 are read out.
The color signal G.sub.1 which is the color signal being thus written in and the color signals R.sub.1 and B.sub.0 read out of the R frame memory 58a and B frame memory 58c are output to the monitor 6.
During the inserting operation, in case the position of the tip part 11 is to be confirmed, the operator switches on the body outside light observing switch 47 provided in the light source apparatus 3. By this on-signal, the filter moving motor 31 will start driving and the rotary color filter 24 will begin to retreat from the light path as in FIG. 18(c). In this moving period T.sub.1, the illuminating light is indefinite. At the time when the movement of the rotary color filter is completed, the illuminating light will become a white light increased in brightness and it will be easy to confirm the position of the tip part 11 with the light transmitted from within the body. By the on-signal of the body outside observing switch 47, the control circuit 46 will inhibit writing into the respective frame memories 43R, 43G and 43B, the picture image in the monitor 6 will be made a color still picture image which is a picture image different from the normal observing picture image and the color picture image just before the rotary color filter 24 moves will be displayed.
When the operator then ends the confirmation of the tip position with the transmitted light of the body outside light, the body outside light observing switch 47 will be again switched on. By this on-signal, the rotary color filter having retreated out of the light path will begin to move into the light path. After the end of the moving period T.sub.3, the movement will end and, when the illuminating light changes to R (red), G (green) and B (blue) separated from the white light, the control circuit 46 will release the inhibition of writing into the respective frame memories 43R, 43G and 43B. The new video data of the observed part illuminated by the respective color lights of R (red), G (green) and B (blue) are sequentially written into the respective frame memories 43R, 43G and 43B and are simultaneously read out to display a color moving picture which is a normal observing picture image on the picture in the monitor 6.
In this embodiment, during the period T.sub.4 which is the sum of the periods T.sub.1 and T.sub.3 when the rotary color filter 24 moves and the period T.sub.2, when it is fixed out of the light path, the picture image is made a color still picture image. Therefore, during the operation of confirming the position of the tip part with the body outside light, no ugly picture image will be displayed.
In the timing chart view in FIG. 20, by the fall of the on-signal of the body outside light observing switch 47, the filter moving motor 31 will start driving and the color transmitting filters 23R, 23G and 23B of the rotary color filter 24 will retreat out of the light path after the moving period T.sub.1. Further, by the fall of the on-signal, the one-shot circuit 48 will output one-shot pulses of an output pulse width T.sub.6 somewhat longer than the filter moving period T.sub.1. While these one-shot pulses are being input, the control circuit 46 will inhibit writing into the respective frame memories 43R, 43G and 43B to make the picture image in the monitor 6 a color still picture image. When the rotary color filter 24 retreats, after the period T.sub.6, the control circuit 46 will release the inhibition of writing into the respective frame memories 43R, 43G and 43B. In this case, the illuminating light will be a white light and therefore the picture image in the monitor 6 will be a black and white moving picture which is a picture image different from the normal observing picture image.
When the confirmation of the tip position with the body outside transmitted light ends, the body outside light observing switch 47 will be switched on. By the fall of this on-signal, the rotary color filter 24 will begin to move to insert the color transmitting filters 23R, 23G and 23B into the light path and will end the insertion into the light path after the moving period T.sub.3. Further, by the fall of this on-signal, the one-shot circuit 48 will again deliver pulses of an output pulse width T.sub.6. While these pulses are being input, the control circuit 46 will inhibit writing into the respective frame memories 43R, 43G and 43B to make the picture image in the monitor 6 a black and white still picture image. After the moving period T.sub.3, the rotary color filter 24 will begin to rotate and will sequentially emit the illluminating light separated into the respective color lights of R (red), G (green) and B (blue). After the period T.sub.6, the control circuit 46 will release the inhibition of writing into the respective frame memories 43R, 43G and 43B and a color moving picture which is an ordinary observing picture image will be displayed in the monitor 6.
According to this embodiment, only in the periods (T.sub.1 and T.sub.3) when the rotary color filter 24 moves, the picture image will be made a still picture image. Therefore, even at the time of the body outside observation, though a black and white picture image, a moving picture will be able to be displayed in the monitor 6, the movement of the insertable part 7 will be able to be sighted and the operation will be safe. At the time of the movement of the rotary color filter, an ugly picture image will be able to be prevented from being output.
In the timing chart view in FIG. 22, by the on-signal of the body outside observing switch 47, the filter moving motor 31 will start driving and the color transmitting filters 23R, 23G and 23B of the rotary color filter will move out of the light path. After the moving period T.sub.1, the color transmitting filters 23R, 23G and 23B will be retreated out of the light path. When this on-signal is input into the flash circuit 49, pulses of such pulse width T.sub.5 as in FIG. 22(d) will be output to the control circuit 46 for a fixed pause period T.sub.7 and the light amount of the light source lamp 22 will be increased synchronously with these pulses. During this pulse width T.sub.5, the control circuit 46 will inhibit writing into the respective frame memories 43R, 43G and 43B and the picture image in the monitor 6 will be made a still picture image which is a picture image different from the ordinary observing picture image and, during the pause period T.sub.7, the inhibition of writing into the respective frame memories 43R, 43G and 43B will be released. In case the writing-in inhibition is released, the illuminating light will be a white light and therefore the picture image in the monitor 6 will be a black and white moving picture which is a picture image different from the ordinary observing picture image. The flash circuit 49 will keep on delivering pulses until the on-signal is input from the body outside observing switch 47.
By the way, during the pause period T.sub.7, the light source lamp 73 will output a light amount adapted to the normal color observation within the body but, during the pulse period T.sub.5, it will output a light amount larger than the light amount adapted to the color observation. This larger light amount goes out of the body through the inner wall of the body cavity to be able to confirm the position of the tip part 11.
When the confirmation of the tip position with the body outside transmitted light ends, the body outside observing switch 47 will be switched on. By this on-signal, the rotary color filter 24 will begin to move to insert the color transmitting filters 23R, 23G and 23B into the light path and will end the insertion after the moving periot T.sub.3. Further, by on-signal, the flash circuit 49 will stop the output of the next pulses and the control circuit 46 will release the inhibition of writing into the respective frame memories 43R, 43G and 43B. After the moving period T.sub.3 the rotary color filter 24 will start the rotation and will sequentially emit the illuminating light separated into respective color lights of R (red), G (green) and B (blue) to display a color moving picture which is an ordinary observing picture image in the monitor 6. By the way, the flash period T.sub.5 may be made longer than the moving period T.sub.1 so that a still picture image may be made in the moving period T.sub.1. Further, while the pulses are being input into the control circuuit 46, the picture image in the monitor 6 may be made a still picture image.
According to this embodiment, only during the flash period T.sub.5, the picture image in the monitor 6 will be made a still picture image which is a picture image different from the normal observing picture image and therefore, in both periods when the rotary color filter 24 moves and at the time of the body outside light observation, a moving picture will be able to be observed, the safety will be higher and such ugly picture image as will be made really white by flashing will be able to be prevented.
In the case of confirming the position of the tip part 11, when the body outside light observing switch 47 is pushed, the on-signal from this switch 47 will be input into the flash circuit 49 and switch 104. When the on-signal is input, the flash circuit 49 will output to the light source lamp 73 pulses of such pulse width T.sub.5 as in FIG. 24(c) for a fixed pause period T.sub.7 to intermittently light the light source lamp 73. By the way, the light source lamp 73 will output a light amount adapted to the normal body interior color observation in the pause period T.sub.7 but will output a light amount larger than the light amount adapted to the color observation in the pulse period T.sub.5. This larger light amount can go out of the body through the inner wall of the body cavity and can be used to confirm the position of the tip part 11. The flash circuit 49 will keep on delivering pulses until the on-signal is input from the body outside light observing switch 47.
On the other hand, in the special light rotary color filter 131 for the special picture images, filters 134a, 134b and 134c transmitting the lights in the narrrow bands with such wavelengths λ.sub.11, λ.sub.12 and λ.sub.13 as are shown in FIG. 29 as centers are arranged in the peripheral direction as shown in FIG. 27.
The separated illuminating lights of the wavelength bands λ.sub.11, λ.sub.12 and λ.sub.13 are radiated onto the inner wall 20 of the body cavity through the light guide 29. The returning lights from the inner wall 20 of the body cavity have such data of the object as can not be obtained with the visible lights R, G and B and form an image on the solid state imaging device 34 through the objective lens system 33 the same as the visible lights. Thereafter, the same signal processing as with the visible lights is made. For example, the picture image data based on the wavelength λ.sub.11 are written into the frame memory 43R, the picture image data based on the wavelength λ.sub.12 are written into the frame memory 43G and the picture image data based on the wavelength λ.sub.13 are written into the frame memory 43B, respectively.
Then, the picture image data are simultaneously read out of the respective frame memories and are displayed in the monitor 6. In the picture image data output from the respective frame memories 43, red (R) corresponds to the wavelength λ.sub.11, green (G) corresponds to the wavelength λ.sub.12 and blue (B) corresponds to the wavelength λ.sub.13, respectively. The display in the monitor 6 becomes a quasi-color moving picture as a normal observing picture image.
On the other hand, a lamp 143 emitting lights in a wide band from ultraviolet rays to infrared rays is provided within the control apparatus 4 and may be a general xenon lamp or strobe lamp which emits a large amount of not only a visible light but also ultraviolet rays and infrared rays. This lamp 143 is fed by a power source part 144 with an electric power. A rotary filter 147 rotated and driven by a motor 146 is arranged in front of the above mentioned lamp 143 and has two concentrically sectioned parts as shown in FIG. 31. On the outer peripheral part side of the rotary filter 147, visible light observing filters 133a, 133b and 133c transmitting the lights of the wavelength regions of red (R), green (G) and blue (B) are arranged in the peripheral direction and, on the inner peripheral part side, special light observing filters 134a, 134b and 134c transmitting the lights of the narrow bands with the wavelengths λ.sub.11, λ.sub.12 and λ.sub.13 as centers are arranged in the peripheral direction. A fan-shaped light intercepting part 148 having a black and white filter 149 is provided in the outer peripheral edge part of the rotary filter 147.
By the way, the transmitting characteristics of the above mentioned filters 134a, 134b and 134c are shown in FIG. 28. The wavelengths λ.sub.11, λ.sub.12 and λ.sub.13 are set as shown in FIG. 29. That is to say, a set of such wavelength groups for special picture images as of λ.sub.11, λ.sub.12 and λ.sub.13 is a combination of such wavelength at which the light absorbing degree of the blood varies with the variation of the oxygen saturation degree (mentiond also as SO.sub.2) of hemoglobin as, for example, λ.sub.12, and such wavelengths which are near that wavelength and at which the light absorbing degree of the blood varies little with the variation of the SO.sub.2 as, for example, λ.sub.11 and λ.sub.13 as shown in FIG. 32.
By the way, in FIG. 32, in order to show the variation of the light absorbing degree of the blood with the variation of the SO.sub.2, the spectral light absorption characteristics of oxyhemoglobin and deoxyhemoglobin are shown.
As shown in FIG. 32, in 300 to 1000 nm., as wavelength groups for special picture images, there can be set not only the above mentioned λ.sub.11, λ.sub.12 and λ.sub.13 in 300 to 400 nm. but also λ.sub.21, λ.sub.22 and λ.sub.23 near 400 nm., λ.sub.31, λ.sub.32 and λ.sub.33 in 400 to 500 nm., λ.sub.41, λ.sub.42 and λ.sub.43 in 500 to 600 and λ.sub.51, λ.sub.52 and λ.sub.53 in 450 to 850. The transmitted wavelengths of the filters 134a, 134b and 134c of the above mentioned rotary filter 147 are not limited to the above mentioned λ.sub.11, λ.sub.12 and λ.sub.13 but any wavelength group can be selected from among the above described five wavelength groups.
On the other hand, when a signal for observing another special light other than the visible light is input from the above mentioned switching circuit 152, the filter switching apparatus 153 will interpose the special light observing filters 134a, 134b and 134c in the illuminating light path. Then, the light emitted from the above mentioned lamp 13 will be divided in time series into the lights of the wavelength groups (λ.sub.11, λ.sub.12 and λ.sub.13) of the above mentioned rotary filter 147. These lights are transmitted to the tip part 11 through the light guide 29 and are radiated onto the object. The returning lights from the object by these illuminating lights are made to form an image on the solid state imaging device 34 by the objective lens system 33 and the object image is imaged by this solid state imaging device 34. Thereafter, the same as in the visible light, the lights are processed to be signals and a quasi-color picture image by the wavelength groups (λ.sub.11, λ.sub.12 and λ.sub.13) is displayed in the monitor 6. With this picture image, the variation of the SO.sub.2 and hemoglobin amounts can be observed.
When a special light picture image is selected, the R, G and B signals from the above mentioned video processor 6 will be processed and a picture image showing the SO.sub.2 and hemoglobin amounts will be able to be obtained.
On the other hand, in the light source part, a rotary filter 162a has three concentrically sectioned parts as shown in FIG. 34. In the outermost peripheral part, visible light observing filters 163a, 163b and 163c transmitting respectively the lights of the wavelength regions of red (R), green (G) and blue (B) are arranged in the peripheral direction, in the central part, special light observing filters 164a, 164b and 164c transmitting respectively the lights of the narrow bands with the wavelengths λ.sub.11, λ.sub.12 and λ.sub.13 as centers are arranged in the peripheral direction and, in the innermost peripheral part, special light observing filters 166a, 166b and 166c transmitting respectively the lights of the narrow bands with the wavelengths λ.sub.21, λ.sub.22 and λ.sub.23 as centers are arranged in the peripheral direction.
By the way, the wavelengths λ.sub.11, λ.sub.12, λ.sub.13, λ.sub.21, λ.sub.22 and λ.sub.23 transmitted respectively by the above mentioned filters 164a, 164b, 164c, 166a, 166b and 166c are the same as the wavelengths described in the tenth embodiment.
In the above mentioned special light observing rotary filter 182, filters 182a, 182b and 182c transmitting the lights of the narrow bands having wavelengths λ.sub.1, λ.sub.2 and λ.sub.3 as centers as shown in FIG. 37 are arranged in the peripheral direction.
By the way, the combination of the above mentioned wavelengths λ.sub.1, λ.sub.2 and λ.sub.3 may be any of five wavelength groups of such λ.sub.11, λ.sub.12 and λ.sub.13 as in FIG. 32. However, the combination of the transmitted wavelength ranges of the respective filters is different between the rotary filter 131 and rotary filter 182.
On the other hand, the position of the tip part 11 of the endoscope 2 is confirmed in the case that the rotary filter 182 is in the illuminating light path. That is to say, the light of the wavelength λ.sub.3 obtained by the filter 182a comes out of the body through the inner wall of the body cavity. Outside the body, the infrared ray camera 176 is in the position of obtaining the light transmitted from within the body and photographs this image. The photographed image is transmitted to the camera control unit 177 and the position of the tip part 11 is displayed in the monitor 178. The picture image displayed in the monitor 178 is a black and white moving picture based on the light of the wavelength λ.sub.3 and different from the normal observing picture image.
By the way the control apparatus 4 applies a clock to the timing generator 179 which outputs by this clock to the camera control unit 177 a timing signal synchronized with the rotary filtler 182. The camera control unit 177 controls the shutter not illustrated of the infrared ray camera 176 to receive the light with the filter 182a only in case the light of the wavelength λ.sub.3 is radiated so that the transmitted light from within the body may be received at a favorable S/N ratio.