Patent Application
20070285771
Referring now to
As shown in
The insertion section 2 has an extremely thin external dimension which allows insertion into the body cavity of the living body, and includes the image pickup unit 3 and a light guide (light guide optical system) 7 that propagates light from the light source unit 4 to a distal end 2a in the interior thereof.
The light source unit 4 includes an illumination light source 8 that emits illumination light (irradiation light) for illuminating an object to be observed A in the body cavity and acquiring reflected light which is reflected from the object to be observed and returned (illumination light), an excitation light source 9 that emits excitation light to be radiated onto the object to be observed in the body cavity and exciting fluorescent substances existing in the object to be observed for causing the fluorescent light to be generated, and a light source control circuit 10 for controlling the light sources 8 and 9.
The illumination light source 8 is, for example, a combination of a xenon lamp and a band-pass filter, not shown, and the 50% transmission area of the band-pass filter ranges from 430 nm to 460 nm. That is, the illumination light source 8 is adapted to generate illumination light in a wavelength band from 430 nm to 460 nm.
The excitation light source 9 is, for example, a semiconductor laser that emits excitation light having a peak wavelength of 405±5 nm. The excitation light having this wavelength excites a plurality of autofluorescent components shown in
The light source control circuit 10 is adapted to turn on and off the illumination light source 8 and the excitation light source 9 at a predetermined timing according to a timing chart, described later.
As shown in
The variable spectroscopic element 13 is an etalon-type optical filter including two plate-shaped optical members 13a and 13b arranged in parallel at a distance and having reflection films on opposing surfaces thereof and an actuator 13c for varying the distance between the optical members 13a and 13b. The actuator 13c is, for example, a piezoelectric element. The variable spectroscopic element 13 is adapted to be able to vary the wavelength band of light which transmits therethrough by varying the distance between the optical elements 13a and 13b by the operation of the actuator 13c.
More specifically, as shown in
In the first embodiment, the variable spectroscopic element 13 includes the variable pass band in a wavelength band which includes wavelengths belonging to a long wavelength side (for example, from 620 nm to 650 nm), from between two types of fluorescent light (autofluorescent light) outputted by the substances existing originally in the living body being excited by the excitation light. The variable spectroscopic element 13 is adapted to be varied into two states according to control signals supplied from the control unit 5.
The first state of the variable spectroscopic element 13 is a state in which the transmittance in the variable pass band is increased to 50% or more to transmit the autofluorescent light on the long wavelength side. The second state of the variable spectroscopic element 13 is a state in which the transmittance in the variable pass band is decreased to 20% or lower to block the autofluorescent light on the long wavelength side.
In the second state, the variable spectroscopic element 13 may block the autofluorescent light by varying the wavelength band of the variable pass band from the first state.
The fixed pass band of the variable spectroscopic element 13 is arranged, for example, in a range from 430 nm to 560 nm, and is fixed to a transmittance of 60% or more.
The fixed pass band of the variable spectroscopic element 13 is positioned in a wavelength band including wavelengths of the autofluorescent light on the short wavelength side and wavelengths of reflected light of the illumination light. Accordingly, the variable spectroscopic element 13 is adapted to allow the autofluorescent light on the short wavelength side and the reflected light to transmit toward the image pickup element 14 either in the first and second states.
According to the transmittance characteristics of the excitation light cutting filter 12, the OD value is at least 4 (=transmittance 1×10−4 or smaller) in a wavelength band from 395 nm to 415 nm and the transmittance is at least 80% in a wavelength band from 430 nm to 650 nm.
As shown in
The image pickup element control circuit 15 and the variable spectroscopic element control circuit 16 are connected to the light source control circuit 10. Accordingly, the image pickup element control circuit 15 and the variable spectroscopic element control circuit 16 are adapted to drive and control the variable spectroscopic element 13 and the image pickup element 14 synchronously with switching between the illumination light source 8 and the excitation light source 9 by the light source control circuit 10.
Specifically, as shown in a timing chart in
Therefore, the image data stored in the first frame memory 17a is image data acquired by bringing the variable spectroscopic element 13 into the first state and radiating the excitation light, and hence is first fluorescent image data in which two fluorescent components are mixed. The image data stored in the second frame memory 17b is image data acquired by bringing the variable spectroscopic element 13 into the second state and radiating the excitation light, and hence is second fluorescent image data including only the fluorescent components on the short wavelength side. Moreover, the image data stored in the third frame memory 17c is image data acquired by brining the variable spectroscopic element 13 into the first state and radiating the illumination light, and hence is reflected light image data.
The image processing circuit 18 is adapted to, for example, receive the second fluorescent image data from the second frame memory 17b and output the same to a first channel of the display unit 6, receive the first and second fluorescent image data from the first and second frame memories 17a and 17b and output image data acquired by subtracting the second fluorescent image data from the first fluorescent image data to a second channel of the display unit 6, and receive reflected light image data from the third frame memory 17c and output the same to a third channel of the display unit 6.
Operation of the endoscope system 1 according to the first embodiment configured as described thus far will be described below.
In order to pick up an image of the object to be observed A in the body cavity of the living body using the endoscope system 1 according to the first embodiment, the insertion section 2 is inserted into the body cavity to oppose the distal end 2a thereof to the object to be observed A in the body cavity. In this state, the light source unit 4 and the control unit 5 are operated to cause the light source control circuit 10 to be operated to switch the light source between the illumination light source 8 and the excitation light source 9 and activate the same, so that the illumination light and the excitation light are generated, respectively.
The excitation light and the illumination light generated in the light source unit 4 are propagated to the distal end 2a of the insertion section 2 respectively via the light guide 7, and is radiated from the distal end 2a of the insertion section 2 onto the object to be observed A.
When the object to be observed A is irradiated with the excitation light, the fluorescent substances originally existing in the object to be observed A are excided and two types of autofluorescent light are emitted. The autofluorescent light emitted from the object to be observed A is collected by the image pickup optical system 11 of the image pickup unit 3, is transmitted through the excitation light cutting filter 12, and enters the variable spectroscopic element 13.
Since the variable spectroscopic element 13 is maintained in the first state synchronously with the operation of the excitation light source 9 by operation of the variable spectroscopic element control circuit 16, the transmittances for the two autofluorescent components are increased, and both of the incoming two autofluorescent components are transmitted therethrough. Then, the two autofluorescent components transmitted through the variable spectroscopic element 13 enter the image pickup element 14, and first fluorescent image data is acquired. The acquired first fluorescent image data is stored in the first frame memory 17a.
In this case, a part of the excitation light being radiated onto the object to be observed A is reflected from the object to be observed A, and enters the image pickup unit 3 together with the autofluorescent components. However, since the image pickup unit 3 is provided with the excitation light cutting filter 12, the excitation light is blocked and hence is prevented from entering the image pickup element 14.
Subsequently, the variable spectroscopic element 13 is switched to the second state after a predetermined time has elapsed from the operation of the excitation light source 9 by operation of the variable spectroscopic element control circuit 16. Accordingly, the transmittance for the autofluorescent light components on the long wavelength side is lowered, and only the autofluorescent components on the short wavelength side from between the entering two autofluorescent components are transmitted. Then, the autofluorescent components on the short wavelength side transmitted through the variable spectroscopic element 13 enter the image pickup element 14 and the second fluorescent image data is acquired. The acquired second fluorescent image data is stored in the second frame memory 17b.
On the other hand, when the object to be observed A is irradiated with the illumination light, the illumination light is reflected from the surface of the object to be observed A, is collected by the image pickup optical system 11, is transmitted through the excitation light cutting filter 12, and enters the variable spectroscopic element 13. Since the wavelength band of the reflected light of the illumination light is positioned in the fixed pass band of the variable spectroscopic element 13, the entire reflected light entering the variable spectroscopic element 13 transmits through the variable spectroscopic element 13.
Then, the reflected light transmitted through the variable spectroscopic element 13 enters the image pickup element 14, and reflected light image data is acquired. The acquired reflected light image data is stored in the third frame memory 17c.
Subsequently, the image processing circuit 18 reads the first and second fluorescent image data stored in the first and second frame memories 17a and 17b and subtracts the second fluorescent image data from the first fluorescent image data. Accordingly, the image processing circuit 18 generates the fluorescent image data of the autofluorescent components on the long wavelength side, outputs the same to the second channel of the display unit 6, outputs the second fluorescent image data read from the second frame memory 17b as is to the first channel of the display unit 6, and outputs the reflected light image data read from the third frame memory 17c as is to the second channel of the display unit 6 to be displayed on the display unit 6.
In this manner, according to the endoscope system 1 in the first embodiment, an image formed by combining the two types of images, that is, the autofluorescent image and the reflected light image is provided to a user.
In this case, according to the endoscope system 1 in the first embodiment, the state of the variable spectroscopic element 13 is switched synchronously with the switching of the plurality of light sources 8 and 9 in the light source unit 4 and the state of the variable spectroscopic element 13 is switched while radiation of the excitation light from the excitation light source 9 so that the two fluorescent image data and the one reflected light image data are acquired at the same position in a time-sharing manner.
Consequently, the two fluorescent image data and the one reflected light image data are acquired before the relative position or the posture of the image pickup element 14 with respect to the object to be observed A is changed, so that accurate extraction of the fluorescent image on the long wavelength side by arithmetic processing between the fluorescent images is achieved. In the case of displaying the reflected light image and the fluorescent image in a superimposed manner, a clear image display without any misalignment is achieved without performing complicated correcting process. Consequently, complexity of the endoscope system 1 is prevented.
Since the state of the variable spectroscopic element 13 is switched synchronously with switching of the plurality of light sources 8 and 9 in the light source unit 4, images of a plurality of types of fluorescent light or reflected light in different wavelength bands are picked up by the identical image pickup element 14. Therefore, it is not necessary to provide a plurality of image pickup optical systems corresponding to the fluorescent light or reflected light. Consequently, the diameter of the insertion section 2 may be reduced.
According to the endoscope system 1 in the first embodiment, since the variable spectroscopic element 13 which varies the transmittance characteristics only by changing the distance between the plate-shaped optical members 13a and 13b is employed, the extremely compact variable spectroscopic element 13 and image pickup element 14 is arranged at the distal end 2a of the insertion section 2. Therefore, it is not necessary to take the fluorescent light or the reflected light from the object to be observed A out of the body using a fiber bundle.
Since outside light which transmits anatomy exists even in the body cavity of the living body, it is important to reduce noise when observing weak light such as the case of the fluorescent observation. However, in the first embodiment, since light other than light having a wavelength of the object to be observed is always blocked even when the wavelength band to be observed is varied by providing the variable spectroscopic element 13 in the image pickup unit 3, preferred image in which the noise is reduced is acquired.
In addition, in the first embodiment, the illumination light source 8 generates the illumination light in a wavelength band from 430 nm to 460 nm. The wavelength band includes a light-absorbing band of hemoglobin, and hence data such as the structure of blood vessels located relatively near the surface of the living body is acquired by picking up the image of the reflected light therefrom.
In the endoscope system 1 according to the first embodiment, the image pickup optical system 11, the excitation light cutting filter 12, and the variable spectroscopic element 13 are arranged in the image pickup unit 3 from the distal end 2a side of the insertion section 2 in this order. However, the order of arrangement of these components is not limited thereto, and the arbitrary order of arrangement is employed.
Subsequently, referring to
In the description of the second embodiment, parts having common structure as the above described endoscope system 1 according to the first embodiment are represented by the same reference numerals and description thereof is omitted.
The endoscope system 1′ according to the second embodiment picks up an image of one type of agent fluorescence in addition to the endoscope system 1 according to the first embodiment which picks up images of the two types of autofluorescent light and the reflected light.
A light source unit 4′ includes another excitation light source 20 in addition to the excitation light source 9 as shown in
The excitation light source 20 is a semiconductor laser that emits excitation light having a peak wavelength of, for example, 660±5 nm. The excitation light having this wavelength is able to excite the fluorescent agent which generates fluorescent light having a peak near 700 nm.
The variable spectroscopic element 13 includes a transmittance wavelength characteristic having two pass bands, that is, one fixed pass band and one variable pass band, as shown in
In the second embodiment, the variable spectroscopic element 13 is adapted to move the variable pass band to three states according to control signals supplied from the control unit 5′.
That is, the first state of the variable spectroscopic element 13 is a state in which the variable pass band coincides with the wavelength band including the wavelengths belonging to the long wavelength side (for example, from 620 nm to 650 nm), from between two types of fluorescent light (autofluorescent light) emitted by the substances originally existing in the living body being excited by the excitation light. Accordingly, the autofluorescent light on the long wavelength side is transmitted.
The third state of the variable spectroscopic element 13 is a state in which the variable pass band coincides with the wavelength band of the agent fluorescence (for example, from 685 nm to 715 nm) . Accordingly, the agent fluorescent light is transmitted.
The second state of the variable spectroscopic element 13 is a state in which the variable pass band is included in a wavelength band different from the first state and the third state (for example, 565 nm to 595 nm) . Accordingly, the autofluorescent light and the agent fluorescent light on the long wavelength side is blocked.
The fixed pass band of the variable spectroscopic element 13 is arranged in a range, for example, from 430 nm to 560 nm, and is fixed to a transmittance of 60% or more.
The fixed pass band of the variable spectroscopic element 13 is included in a wavelength band including the wavelength of the autofluorescent light on the short wavelength side and the wavelength of the reflected light of the illumination light, so that the autofluorescent light and the reflected light on the short wavelength side are transmitted toward the image pickup element 14 in either of the first and second states.
According to the transmittance characteristics of the excitation light cutting filter 12, the OD value is at least 4 (=transmittance 1×10−4 or smaller) in a wavelength band from 395 nm to 415 nm and the transmittance is at least 80% in a wavelength band from 430 nm to 650 nm.
In addition to the excitation light cutting filter 12, it is preferable to arrange a notch filter having the transmittance characteristics which achieve the OD value of at least 2 (=transmittance 1×10−2 or smaller) in the wavelength band from 570 nm to 590 nm, and a transmittance of 50% or more in a wavelength bands from 430 nm to 560 nm and from 600 nm to 720 nm. In this configuration, the transmittance characteristics on the long wavelength side of the fixed pass band which vary in association with the switching of the variable pass band in the variable spectroscopic element 13 may be collected.
As shown in a timing chart in
After having elapsed a predetermined time from emission of the first excitation light from the excitation light source 9, the variable spectroscopic element control circuit 16 brings the variable spectroscopic element 13 into the second state, and image pickup element control circuit 15 causes the image data outputted from the image pickup element 14 to be outputted to the second frame memory 17b.
When the second excitation light is emitted from the excitation light source 20, the variable spectroscopic element control circuit 16 switches the variable spectroscopic element 13 into the third state, and the image pickup element control circuit 15 causes the image data outputted from the image pickup element 14 to be outputted to the third frame memory 17c.
When the illumination light is emitted from the illumination light source 8, the variable spectroscopic element control circuit 16 switches the variable spectroscopic element 13 into the first state again, and the image pickup element control circuit 15 causes the image data outputted from the image pickup element 14 to be outputted to the fourth frame memory 17d.
When the illumination light is emitted from the illumination light source 8, the variable spectroscopic element control circuit 16 is adapted to switch the variable spectroscopic element 13 into the first state again, and the image pickup element control circuit 15 is adapted to cause the image data outputted from the image pickup element 14 to be outputted to the fourth frame memory 17d.
Therefore, since the image data stored in the first frame memory 17a is image data acquired by bringing the variable spectroscopic element 13 into the first state and radiating the first excitation light, it is mixed autofluorescent image data in which the two autofluorescent components are mixed. Since the image data stored in the second frame memory 17b is image data acquired by bringing the variable spectroscopic element 13 into the second state and radiating the first excitation light, it is short wavelength autofluorescent image data which only includes the autofluorescent components on the short wavelength side. Moreover, since the image data stored in the third frame memory 17c is image data acquired by bringing the variable spectroscopic element 13 into the third state and radiating the second excitation light, it is agent fluorescent image data including only the agent fluorescent light. Since the image data stored in the fourth frame memory 17d is image data acquired by bringing the variable spectroscopic element 13 into the first state and radiating the illumination light, it is reflected light image data.
An observation mode selection circuit 25 is adapted to select the image data to be displayed by input operation of an observer. As described above, the endoscope system 1′ according to the second embodiment acquires four images including the two autofluorescent components, the one agent fluorescent component and the reflected light component. The output channel of the normal display unit 6 includes the first to third channels of red, green, and blue, so that three images are selected from among four images and are displayed in a superimposed manner via the observation mode selection circuit 25.
For example, when superimposed display of the short wavelength autofluorescent image data, the agent fluorescent image data, and the reflected light image data is desired, the image data stored in the second to fourth frame memories 17b to 17b may be outputted as is to the first to third channels of the display unit 6.
When display of the long wavelength autofluorescent image data including only the autofluorescent components on the long wavelength side is desired, the observation mode selection circuit 25 may activate the image processing circuit 18, calculate the long wavelength autofluorescent image data by subtracting the short wavelength autofluorescent image data received from the second frame memory 17b from the mixed autofluorescent image data received from the first frame memory 17a, and output the calculated result to any one of the channels of the display unit 6.
Operation of the endoscope system 1′ according to the second embodiment configured in this manner will be described below.
Here, a case in which the autofluorescent image data, the agent fluorescent image data, and the reflected light image data on the long wavelength side of the object to be observed A in the body cavity of the living body are displayed in a superimposed manner on the display unit 6 will be described using the endoscope system 1′ according to the second embodiment.
In order to observe the object to be observed A using the endoscope system 1′ according to the second embodiment, firstly, fluorescent agent is injected into the body, the insertion section 2 is inserted into the body cavity, and the distal end 2a thereof is opposed to the object to be observed A in the body cavity. In this state, the light source unit 4′ and the control unit 5′ are activated, the illumination light source 8 and the excitation light sources 9 and 20 are switched and activated to generate illumination light and the first and second excitation light respectively.
The first and second excitation light and the illumination light generated by the light source unit 4 are propagated to the distal end 2a of the insertion section 2 via the light guide 7 respectively, and radiated onto the object to be observed A from the distal end 2a of the insertion section 2.
When the object to be observed A is irradiated with the first excitation light, the fluorescent substances originally existing on the object to be observed A is excited and hence two types of autofluorescent light are emitted. The autofluorescent light emitted from the object to be observed A is collected by the image pickup optical system 11 of the image pickup unit 3, is transmitted through the excitation light cutting filter 12, and enters the variable spectroscopic element 13.
The variable spectroscopic element 13 is maintained in the first state synchronously with the operation of the excitation light source 9 by the operation of the variable spectroscopic element control circuit 16. Accordingly, the transmittances for the two autofluorescent components are increased, and both of the entering two autofluorescent light components are transmitted. Then, the two autofluorescent components transmitted though the variable spectroscopic element 13 enters the image pickup element 14, and the mixed autofluorescent image data is acquired. The acquired mixed autofluorescent image data is stored in the first frame memory 17a.
In this case, a part of the excitation light radiated onto the object to be observed A is reflected from the object to be observed A, and enters the image pickup unit 3 together with the autofluorescent component. However, since the excitation light cutting filter 12 is provided in the image pickup unit 3, the excitation light is blocked and is prevented from entering the image pickup element 14.
Subsequently, the variable spectroscopic element 13 is switched into the second state after having elapsed a predetermined time from the operation of the excitation light source 9 by the operation of the variable spectroscopic element control circuit 16. Accordingly, only the autofluorescent component on the short wavelength side from between the two autofluorescent components entering the variable spectroscopic element 13 is transmitted. Then, the autofluorescent component on the short wavelength side transmitted through the variable spectroscopic element 13 enters the image pickup element 14, and the short wavelength autofluorescent image data is acquired. The acquired short wavelength autofluorescent image data is stored in the second frame memory 17b.
When the object to be observed A is irradiated with the second excitation light, the fluorescent agent permeated into the object to be observed A is excited and hence the agent fluorescent light is emitted. The agent fluorescent light is collected by the image pickup optical system 11 of the image pickup unit 3, is transmitted through the excitation light cutting filter 12, and enters the variable spectroscopic element 13.
The variable spectroscopic element 13 is switched to the third state synchronously with the operation of the excitation light source 20 by the operation of the variable spectroscopic element control circuit 16. Accordingly, the transmittances for the agent fluorescent component of the variable spectroscopic element 13 is increased, so that the entering agent fluorescent light is transmitted. Then, the agent fluorescent light transmitted through the variable spectroscopic element 13 enters the image pickup element 14, and the agent fluorescent image data is acquired. The acquired agent fluorescent image data is stored in the third frame memory 17c.
On the other hand, when the object to be observed A is irradiated with the illumination light, the illumination light is reflected from the surface of the object to be observed A, is collected by the image pickup optical system 11, is transmitted through the excitation light cutting filter 12, and enters the variable spectroscopic element 13. Since the wavelength band of the reflected light of the illumination light is included in the fixed pass band of the variable spectroscopic element 13, the entire reflected light entering the variable spectroscopic element 13 is transmitted through the variable spectroscopic element 13.
The reflected light transmitted through the variable spectroscopic element 13 enters the image pickup element 14, and the reflected light image data is acquired. The acquired reflected light image data is stored in the fourth frame memory 17d.
Subsequently, the image processing circuit 18 generates the long wavelength autofluorescent image data by reading out the mixed autofluorescent image data and the short wavelength autofluorescent image data stored in the first and second frame memories 17a and 17b and subtracting the short wavelength autofluorescent image data from the mixed autofluorescent image data. Then, the long wavelength autofluorescent image data, the agent fluorescent image data, and the reflected light image data calculated in this manner are outputted to the first to third channels of the display unit 6 respectively, so that superimposed display is achieved by the display unit 6.
In this manner, according to the endoscope system 1′ in the second embodiment, an image acquired by combining the long wavelength autofluorescent image, the agent fluorescent image, and the reflected light image may be provided to the user.
In this case, according to the endoscope system 1′ in the second embodiment, the state of the variable spectroscopic element 13 is switched synchronously with the switching of the plurality of light sources 8, 9, and 20 in the light source unit 4′, and the state of the variable spectroscopic element 13 is switched during radiation of the first excitation light from the excitation light source 9, so that the two autofluorescent image data, the one agent fluorescent image data, and the one reflected light image data are acquired at the same position in a time-sharing manner.
Consequently, the three fluorescent image data and the one reflected light image data are acquired before the relative position or the posture of the image pickup element 14 with respect to the object to be observed A is changed, and hence the accurate extraction of the autofluorescent image on the long wavelength side by the arithmetic processing among the fluorescent images is achieved. The three fluorescent images and the one reflected light image are displayed in a superimposed manner, so that a clear image display without misalignment may be achieved without performing a complicated correcting process. Consequently, the complexity of the endoscope system 1′ may be prevented.
In the second embodiment, the case of acquiring all the image data has been described. However, when the long wavelength autofluorescent image data is not displayed, the step of acquiring the mixed autofluorescent image data is not necessary. In the second embodiment, the case of operating all the light sources has been described. However, when there is image data which is not selected, the light source control circuit 10 may be adapted to stop the operation of some light sources under the instruction of the observation mode selection circuit 25. In this case, the variable spectroscopic element control circuit 16 and the image pickup element control circuit 15 are also controlled according to a timing chart different from
It is also applicable to generate a standardized image data acquired by standardizing three image data from the acquired four image data by remaining one image data through the selection of the method of observation by the observation mode selection circuit 25 and display these in a superimposed manner. For example, a configuration to output standardized agent fluorescent image data acquired by dividing the agent fluorescent image data by the long wavelength autofluorescent image data from pixel to pixel to the first channel, standardized autofluorescent image data acquired by dividing the short wavelength autofluorescent image data by the long wavelength autofluorescent image data from pixel to pixel to the second channel, and standardized reflected light image data acquired by dividing the reflected light image data by the long wavelength autofluorescent image data from pixel to pixel may be outputted respectively to the third channel.
In this configuration, there is an advantage such that variation of the exposure value in the image pickup element 14 on the basis of the variation of the light amount from the light source or the variation of the distance from the object to be observed A is adjusted. There is also an advantage such that a portion to be inspected such as a diseased tissue is displayed further distinctly by emphasizing the pixels whose light amount is small through the standardization.
Alternatively, it is also possible to adjust the exposure value in the image pickup element 14 by calculating an average value or a maximum value within an entire or part of the range of any image data, returning a feedback of the same to the light source control circuit 10, and adjusting the light amount of each light source.
Referring now to
The endoscope system 1″ according to the third embodiment is different from the endoscope systems 1 and 1′ according to the first and second embodiments which employ the variable spectroscopic element 13 in that a mosaic filter 30 (spectral means) is used.
The mosaic filter 30 is arranged next to the image pickup element 14 on the upstream side as shown in
The respective filter strips 30a to 30c of the mosaic filter 30 have transmittance characteristics as shown in
Therefore, the same effect as the second embodiment is achieved by storing only image information acquired by the pixels corresponding to the filter strips 30a to 30c of the same type in the same frame memories 17a to 17c respectively using the same light sources 8, 9, and 20 as in the endoscope system 1′ and the timing chart according to the second embodiment.
The fluorescent endoscope systems 1, 1′, and 1″ according to the invention are not limited to a scope type having the image pickup element 14 at the distal end of the insertion section 2 which is inserted into the body cavity of the living body, but a capsule type which includes a light source, an image pickup device, and a variable spectroscopic unit provided in one casing, and may be inserted into the body cavity of the living body entirely as the housing can also be applied.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-148040 | May 2006 | JP | national |
