JP5570352B2 - Imaging device - Google Patents

Description

  The present invention relates to an image pickup apparatus that receives light emitted from an observed portion by irradiating the observed portion with special light and acquires a special image.

  Conventionally, endoscope systems for observing tissue in a body cavity are widely known, and a normal image is obtained by imaging a portion to be observed in a body cavity by irradiation with white light, and this normal image is displayed on a monitor screen. Electronic endoscope systems have been widely put into practical use.

  Moreover, as an endoscope system as described above, for example, in Patent Document 1, an autofluorescence image emitted from an observed part by irradiation of excitation light is captured together with a normal image to obtain autofluorescence images. There has been proposed a fluorescence endoscope system that displays the above image on a monitor screen.

  In addition, as a fluorescence endoscope system, for example, ICG (Indocyanine Green) is put in the body in advance, and the fluorescence image is acquired by detecting the fluorescence of ICG in the blood vessel by irradiating the observation light with the excitation light. Something to do is also proposed.

JP 2005-304600 A

  Here, since the fluorescence endoscope system as described above detects weak fluorescence, in the imaging system that captures a fluorescent image, the observed part is reflected by irradiation with excitation light or white light reflected from the observed part. An excitation light cut filter for cutting the reflected light is provided, and only a fluorescent image is captured with high sensitivity.

  Therefore, only the fluorescent light emission part can be observed on the fluorescent image, and the periphery of the light emission part cannot be observed.

  However, there are cases in which it is desired to confirm in which part of the organ the light emitting part is located on the fluorescent image.

  In Patent Document 1, when observing a fluorescence image by irradiating excitation light, a part of the excitation light is irradiated to the observed part by lowering the threshold of the excitation light cut filter to the visible light side, and the fluorescence image A method for enabling the periphery of the light emitting portion to be visually recognized is disclosed.

  However, in Patent Document 1, since a part of the excitation light is used as illumination light, the intensity of the reflected light of the excitation light and the intensity of the fluorescence cannot be controlled independently, depending on the intensity of the fluorescence. Has a problem that the intensity of reflected light of excitation light is higher than the intensity of fluorescence and the fluorescent part cannot be observed properly.

  In view of the above problems, the present invention can capture an image capturing device that captures a special image such as the above-described fluorescent image so that the light emitting portion of the special image and its peripheral portion can be clearly distinguished, It is an object of the present invention to provide an image pickup apparatus that can grasp the position of a light emitting part in an observed part.

  An image pickup apparatus of the present invention includes a special light irradiating unit that irradiates a portion to be observed with special light, an image pickup device that receives light emitted from the portion to be observed by irradiation of the special light and picks up a special image, and the light And an imaging unit having a special light cut filter that cuts light in a wavelength band equal to or less than the wavelength of the special light, the wavelength of the special light cut filter and the sensitivity of the image sensor An illumination light irradiating unit for irradiating the observed part with illumination light having a wavelength within the range is provided.

  In the image pickup apparatus of the present invention, the special light irradiation unit and the illumination light irradiation unit can be irradiated with the special light and the illumination light independently of each other.

  In addition, the imaging unit receives a light emitted from the observed part by irradiating only the special light to the observed part and picks up a special image, and by irradiating both the special light and the illumination light. Suppose that the light emitted from the observed part is received and a mixed image is captured, and a reflected image corresponding to only the reflected light from the illumination light irradiated on the observed part is obtained based on the mixed image and the special image. And a composite image acquisition unit that acquires a composite image obtained by combining the special image and the reflection image.

  Further, when the signal intensity of the special image is smaller than a constant multiple of 1 or more than the signal intensity of the reflected image, an illumination light control unit that controls the illumination light irradiation unit to reduce the amount of illumination light can be provided. .

  Further, the illumination light control unit can control the illumination light irradiation unit so as to increase the amount of illumination light when the signal intensity of the special image is greater than one constant multiple of the signal intensity of the reflected image. .

  In addition, a normal light irradiating unit that irradiates the observed part with normal light cut by the special light cut filter, and a normal image that receives reflected light reflected from the observed part by irradiating the observed part with normal light. And a normal image capturing unit for capturing the image.

  In addition, the special light irradiation unit irradiates excitation light as special light to the observation part, and the imaging unit receives fluorescence emitted from the observation part by irradiation of excitation light, and displays a fluorescence image as a special image. It can be taken.

  In addition, the illumination light irradiating unit can irradiate light having substantially the same wavelength as the peak wavelength of the light emitted from the observed portion by irradiating special light as illumination light.

  According to the image pickup apparatus of the present invention, the special light irradiation unit that irradiates the observation target part with the special light, the imaging element that receives the light emitted from the observation target part by the special light irradiation, and picks up the special image, and An imaging device including an imaging unit having a special light cut filter that transmits the light and cuts light in a wavelength band equal to or less than the wavelength of the special light. Since the illumination light irradiating unit for irradiating the observation part with illumination light having a wavelength within the sensitivity range is provided, wavelength characteristics that are not cut by the excitation light cut filter as described above when capturing a special image By irradiating the illumination light, the periphery of the light emitting part of the special image can be imaged, and the position of the light emitting part in the observed part can be grasped.

  In the image pickup apparatus of the present invention, when the special light irradiation unit and the illumination light irradiation unit can irradiate the special light and the illumination light independently of each other, for example, A special image is captured by irradiating the observation unit, and a mixed image is captured by irradiating both special light and illumination light. Based on the mixed image and special image, only reflected light from illumination light is applied. Since the reflected image can be acquired, the special image and the reflected image can be distinguished from each other, that is, the light emitting portion and its peripheral portion by special light irradiation can be clearly distinguished and displayed.

1 is a schematic configuration diagram of a rigid endoscope system using an embodiment of an image pickup apparatus of the present invention. Schematic configuration diagram of body cavity insertion part Schematic configuration diagram of the imaging unit The block diagram which shows schematic structure of an image processing apparatus and a light source device Block diagram showing schematic configuration of image processing unit The figure which shows an example of spectrum S1 of excitation light, spectrum S2 of fluorescence wavelength range illumination light, and emission spectrum S3 of fluorescence of ICG The figure for demonstrating the effect | action which displays a synthesized image The figure for demonstrating the method to control the light quantity of fluorescence wavelength region illumination light so that a fluorescence image may not be buried in a reflected image

  Hereinafter, a rigid endoscope system using an embodiment of an image pickup apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is an external view showing a schematic configuration of a rigid endoscope system 1 of the present embodiment.

  As shown in FIG. 1, the rigid endoscope system 1 of the present embodiment includes a light source device 2 that emits white normal light, excitation light, and fluorescent wavelength region illumination light, and normal light and excitation light emitted from the light source device 2. In addition, the fluorescent wavelength region illumination light described later is guided to irradiate the observed part, and the normal image based on the reflected light reflected from the observed part by normal light irradiation and emitted from the observed part by excitation light irradiation. A rigid mirror imaging device 10 that captures a fluorescence image based on the fluorescence and a mixed image based on the light emitted from the observed portion by irradiation with excitation light and fluorescence wavelength region illumination light, and the rigid mirror imaging device 10. An image processing device 3 that performs predetermined processing on the obtained image signal, and a monitor 4 that displays a normal image, a fluorescence image, and a composite image described later based on a display control signal generated in the image processing device 3. Preparation There.

  As shown in FIG. 1, the rigid endoscope imaging apparatus 10 includes a body cavity insertion unit 30 that is inserted into a body cavity, and an imaging unit 20 that captures a normal image and a fluorescence image of the observed portion guided by the body cavity insertion unit 30. And.

  Moreover, as shown in FIG. 2, the rigid-scope imaging device 10 has the body cavity insertion part 30 and the imaging unit 20 connected detachably. The body cavity insertion portion 30 includes a connection member 30a, an insertion member 30b, a cable connection port 30c, and an irradiation window 30d.

  The connection member 30a is provided on one end side 30X of the body cavity insertion part 30 (insertion member 30b). For example, the connection member 30a is fitted into an opening 20a formed on the imaging unit 20 side, whereby the imaging unit 20 and the body cavity insertion part 30 are connected. Are detachably connected.

  The insertion member 30b is inserted into the body cavity when photographing inside the body cavity, and is formed of a hard material and has, for example, a cylindrical shape with a diameter of about 5 mm. A lens group for forming an image of the observed portion is accommodated inside the insertion member 30b, and the normal image and the fluorescent image of the observed portion incident from the other end 30Y pass through the lens group. The light is emitted to the imaging unit 20 side of the one end side 30X.

  A cable connection port 30c is provided on the side surface of the insertion member 30b, and the optical cable LC is mechanically connected to the cable connection port 30c. Thereby, the light source device 2 and the insertion member 30b are optically connected via the optical cable LC.

  The irradiation window 30d is provided on the other end side 30Y of the body cavity insertion portion 30, and irradiates the observed portion with normal light, excitation light, and fluorescent wavelength region illumination light guided by the optical cable LC. The insertion member 30b accommodates a light guide (not shown) for guiding normal light, excitation light, and fluorescent wavelength region illumination light from the cable connection port 30c to the irradiation window 30d. The observation part is irradiated with normal light, excitation light, and fluorescent wavelength region illumination light guided by a guide.

  FIG. 3 is a diagram illustrating a schematic configuration of the imaging unit 20. The imaging unit 20 captures the fluorescent image and the mixed image of the observed part formed by the lens group in the body cavity insertion unit 30 to generate the fluorescent image signal and the mixed image signal of the observed part. And a second imaging system that captures a normal image of the observed portion imaged by the lens group in the body cavity insertion unit 30 and generates a normal image signal. These imaging systems are divided into two optical axes orthogonal to each other by a dichroic prism 21 having a spectral characteristic that reflects a normal image and transmits a fluorescent image and a mixed image. The mixed image will be described later in detail.

  The first imaging system cuts light having a wavelength equal to or less than the wavelength of the excitation light reflected by the observed portion and transmitted through the dichroic prism 21 and an excitation light cut filter 22 that transmits fluorescent wavelength region illumination light, which will be described later, and a body cavity A first imaging optical system 23 that forms a fluorescent image L4 or a mixed image L5 emitted from the insertion unit 30 and transmitted through the dichroic prism 21 and the excitation light cut filter 22 is imaged by the first imaging optical system 23. And a high-sensitivity imaging device 24 that captures the fluorescent image L4 or the mixed image L5.

  The second imaging system includes a second imaging optical system 25 that forms a normal image L3 emitted from the body cavity insertion unit 30 and reflected by the dichroic prism 21, and a normal image formed by the second imaging optical system 25. An image sensor 26 that captures the image L3 is provided.

  The high-sensitivity imaging element 24 detects light in the wavelength band of the fluorescent image L4 with high sensitivity, converts it into a fluorescent image signal, and outputs it. The high-sensitivity imaging device 24 also detects a mixed image L5 emitted from the observed portion by irradiating the observed portion with excitation light and fluorescent wavelength region illumination light, converts it to a mixed image signal, and outputs it. is there. The high sensitivity image sensor 24 is a monochrome image sensor.

  The image sensor 26 detects light in the wavelength band of the normal image, converts it into a normal image signal, and outputs it. On the image pickup surface of the image pickup element 26, color filters of three primary colors red (R), green (G) and blue (B), or cyan (C), magenta (M) and yellow (Y) are arranged in a Bayer array or a honeycomb. It is provided in an array.

  In addition, the imaging unit 20 includes an imaging control unit 27. The imaging control unit 27 performs CDS / AGC (correlated double sampling / automatic gain control) on the fluorescence image signal and the mixed image signal output from the high-sensitivity imaging device 24 and the normal image signal output from the imaging device 26. Processing and A / D conversion processing are performed and output to the image processing apparatus 3 via the cable 5 (see FIG. 1).

  As shown in FIG. 4, the image processing apparatus 3 includes a normal image input controller 31, a fluorescence image input controller 32, an image processing unit 33, a memory 34, a video output unit 35, an operation unit 36, a TG (timing generator) 37, and a CPU 38. It has.

  The normal image input controller 31 and the fluorescence image input controller 32 include a line buffer having a predetermined capacity, and the normal image input controller 31 receives the normal image signal for each frame output from the imaging control unit 27 of the imaging unit 20. The fluorescent image input controller 32 temporarily stores the fluorescent image signal and the mixed image signal. The normal image signal stored in the normal image input controller 31 and the fluorescent image signal and the mixed image signal stored in the fluorescent image input controller 32 are stored in the memory 34 via the bus.

  The image processing unit 33 receives the normal image signal, the fluorescence image signal, and the mixed image signal for each frame read from the memory 34, performs predetermined image processing on these image signals, and outputs them to the bus. is there. A more specific configuration of the image processing unit 33 is shown in FIG.

  As shown in FIG. 5, the image processing unit 33 includes a normal image processing unit 51, a fluorescence image processing unit 52, a mixed image processing unit 53, and a reflected image acquisition unit 54.

  The normal image processing unit 51 performs predetermined image processing suitable for the normal image on the input normal image signal and outputs the processed image.

  The fluorescence image processing unit 52 performs predetermined image processing suitable for the fluorescence image on the input fluorescence image signal and outputs the processed signal.

  The mixed image processing unit 53 performs predetermined image processing suitable for the mixed image on the input mixed image signal and outputs it.

  The reflected image acquisition unit 54 subtracts the fluorescent image signal output from the fluorescent image processing unit 52 from the mixed image signal output from the mixed image processing unit 53 to acquire and output a reflected image signal.

  Returning to FIG. 4, the video output unit 35 receives the normal image signal, the fluorescence image signal, and the reflected image signal output from the image processing unit 33 via the bus, and performs predetermined processing to generate a display control signal. The display control signal is output to the monitor 4.

  The operation unit 36 receives input by the operator such as various operation instructions and control parameters. The TG 37 outputs a driving pulse signal for driving the high-sensitivity imaging device 24, the imaging device 26 of the imaging unit 20, and the LD driver 45 of the light source device 2 described later. The CPU 36 controls the entire apparatus.

  The light source device 2 includes a normal light source 40 that emits normal light (white light) L1 having a broadband wavelength of about 400 to 700 nm, a condenser lens 42 that collects the normal light L1 emitted from the normal light source 40, and A dichroic mirror 43 that transmits normal light L1 collected by the condensing lens 42, reflects excitation light L2 to be described later, and makes the normal light L1 and excitation light L2 enter the incident end of the optical cable LC is provided. Yes. For example, a xenon lamp is used as the normal light source 40. A diaphragm 41 is provided between the normal light source 40 and the condenser lens 42, and the amount of the diaphragm is controlled based on a control signal from an ALC (Automatic light control) 48.

  The light source device 2 includes a near-infrared LD light source 44 that emits near-infrared light of 750 to 790 nm as excitation light L2, an LD driver 45 that drives the near-infrared LD light source 44, and a near-infrared LD light source 44. The condensing lens 46 that condenses the excitation light L2 emitted from the light source, and reflects the excitation light L2 collected by the condensing lens 46 toward the dichroic mirror 43 and transmits fluorescent wavelength region illumination light described later. A dichroic mirror 47 is provided.

  In addition, as excitation light L2, the wavelength of a narrow band is used rather than the normal light which consists of a broadband wavelength. And as excitation light L2, it is not limited to the light of the said wavelength range, It determines suitably according to the kind of fluorescent pigment | dye, or the kind of biological tissue made to autofluoresce.

  In addition, the light source device 2 includes an illumination light LD light source 49 that emits light having substantially the same wavelength as the fluorescence peak wavelength of ICG as fluorescence wavelength region illumination light L0, an LD driver 50 that drives the illumination light LD light source 49, and illumination. And a mirror 57 that reflects the fluorescence wavelength region illumination light L0 emitted from the light LD light source 49 toward the dichroic mirror 47.

  Here, FIG. 6 shows the spectrum S1 of the excitation light L2 emitted from the near-infrared LD light source 44, the spectrum S2 of the fluorescence wavelength region illumination light L0 emitted from the illumination light LD light source 49, and the fluorescence emission of ICG. Spectrum S3 is shown. As described above, in the present embodiment, light having substantially the same wavelength as the peak wavelength of fluorescence of ICG is used as the fluorescence wavelength region illumination light L0. And this fluorescence wavelength range illumination light L0 is the light which permeate | transmits the excitation light cut filter 22 in the 1st imaging system which images the fluorescence image shown in FIG. 3, and is photoelectrically converted by the high sensitivity image sensor 24 with ICG fluorescence. It is what is done.

  Note that the wavelength of the fluorescent wavelength region illumination light L0 is not limited to this wavelength, and any other wavelength can be used as long as it is light that passes through the excitation light cut filter 22 and has a wavelength within the sensitivity range of the high-sensitivity imaging device 24. Light may be used.

  The light source device 2 is optically connected to the rigid mirror imaging device 10 via the optical cable LC.

  Next, the operation of the rigid endoscope system of this embodiment will be described.

  The rigid endoscope system of this embodiment irradiates the fluorescence image of ICG fluorescence by irradiation of excitation light, the normal image by irradiation of white light, and the excitation light and the fluorescence wavelength region illumination light simultaneously. There are some which display a composite image in which a range other than the fluorescent part can be confirmed together with the fluorescent part. First, the operation of displaying the normal image and the fluorescent image will be described.

  First, the body cavity insertion part 30 is inserted into the body cavity by the operator, and the distal end of the body cavity insertion part 30 is installed in the vicinity of the observed part.

  Then, the normal light L1 emitted from the normal light source 40 of the light source device 2 is incident on the body cavity insertion unit 30 via the condenser lens 42, the dichroic mirror 43, and the optical cable LC, and is irradiated from the irradiation window 30d of the body cavity insertion unit 30. Irradiate the observation part. On the other hand, the excitation light L2 emitted from the near-infrared LD light source 44 of the light source device 2 is incident on the body cavity insertion unit 30 via the condenser lens 46, the mirror 47, the dichroic mirror 43, and the optical cable LC, and the body cavity insertion unit 30 The irradiated portion is irradiated simultaneously with the normal light L1 from the irradiation window 30d.

  Then, a normal image based on the reflected light reflected from the observed portion by the irradiation of the normal light L1 is captured, and a fluorescent image based on the fluorescence emitted from the observed portion by the irradiation of the excitation light L2 is captured. It should be noted that ICG is administered to the observed part in advance, and fluorescence emitted from the ICG is imaged.

  Specifically, when capturing the normal image, the normal image L3 based on the reflected light reflected from the observed portion by the irradiation of the normal light L1 is incident from the distal end 30Y of the insertion member 30b, and the inside of the insertion member 30b. The light is guided by the lens group and emitted toward the imaging unit 20.

  The normal image L3 incident on the imaging unit 20 is reflected by the dichroic prism 21 in the direction perpendicular to the imaging element 26, and is imaged on the imaging surface of the imaging element 26 by the second imaging optical system 25. 26 sequentially captures images at a predetermined frame rate.

  The normal image signal sequentially output from the image sensor 26 is subjected to CDS / AGC (correlated double sampling / automatic gain control) processing and A / D conversion processing in the imaging control unit 27, and then the image is transmitted through the cable 5. The data is sequentially output to the processing device 3.

  The normal image signal input to the image processing device 3 is temporarily stored in the normal image input controller 31 and then stored in the memory 34. The normal image signal for each frame read from the memory 34 is subjected to gradation correction processing and sharpness correction processing in the normal image processing unit 51 of the image processing unit 33, and then sequentially output to the video output unit 35. Is done.

  Then, the video output unit 35 performs a predetermined process on the input normal image signal to generate a display control signal, and sequentially outputs the display control signal for each frame to the monitor 4. The monitor 4 displays a normal image based on the input display control signal.

  On the other hand, when the fluorescent image is picked up, a fluorescent image L4 based on the fluorescence emitted from the observed portion by the irradiation of the excitation light is incident from the tip 30Y of the insertion member 30b and guided by the lens group in the insertion member 30b. And emitted toward the imaging unit 20.

  The fluorescent image L4 incident on the imaging unit 20 passes through the dichroic prism 21 and the excitation light cut filter 22, and is then imaged on the imaging surface of the high-sensitivity imaging element 24 by the first imaging optical system 23, and has high sensitivity. Images are taken at a predetermined frame rate by the image sensor 24.

  The fluorescent image signals sequentially output from the high-sensitivity image sensor 24 are subjected to CDS / AGC (correlated double sampling / automatic gain control) processing and A / D conversion processing in the imaging control unit 27, and then passed through the cable 5. Are sequentially output to the image processing apparatus 3.

  The fluorescence image signal input to the image processing device 3 is temporarily stored in the fluorescence image input controller 32 and then stored in the memory 34. Then, the fluorescence image signal for each frame read from the memory 34 is subjected to predetermined image processing in the fluorescence image processing unit 52 of the image processing unit 33 and then sequentially output to the video output unit 35.

  The video output unit 35 performs a predetermined process on the input fluorescent image signal to generate a display control signal, and sequentially outputs the display control signal for each frame to the monitor 4. The monitor 4 displays a fluorescent image based on the input display control signal.

  In a state where the fluorescent image is displayed as described above, the observer may want to check not only the light emitting portion in the fluorescent image but also the range around the light emitting portion. In such a case, the observer gives an instruction to display a composite image using the operation unit 36, and the composite image is displayed in response to this instruction. Hereinafter, the operation of displaying the composite image will be described.

  When displaying the composite image, specifically, in a state where the fluorescent image is captured as described above, the fluorescent wavelength region illumination light emitted from the illumination light LD light source 49 of the light source device 2 is further provided. L0 is incident on the body cavity insertion section 30 via the mirror 57, the dichroic mirror 47, the dichroic mirror 43, and the optical cable LC, and is irradiated to the observed part from the irradiation window 30d of the body cavity insertion section 30.

  At this time, the excitation light L2 is continuously irradiated, but the fluorescence wavelength region illumination light L0 is irradiated in a pulsed manner with a predetermined interval while the excitation light L2 is being irradiated. That is, the illumination light LD light source 49 is driven by alternately turning it on and off, and the pulsed fluorescence wavelength region illumination light L0 is irradiated accordingly.

  When only the excitation light L2 is irradiated, that is, when the fluorescence wavelength range illumination light L0 is off, the same processing as that in the case of capturing the fluorescent image described above is performed, and the image processing unit After the predetermined image processing is performed in the 33 fluorescence image processing units 52, the image is output to the reflected image acquisition unit 54.

  On the other hand, when both the excitation light L2 and the fluorescence wavelength range illumination light L0 are irradiated on the observed part, the light is emitted from the observed part by both the excitation light L2 and the fluorescence wavelength range illumination light L0. The mixed image L5 based on the incident light enters from the tip 30Y of the insertion member 30b, is guided by the lens group in the insertion member 30b, and is emitted toward the imaging unit 20.

  The mixed image L5 incident on the imaging unit 20 passes through the dichroic prism 21 and the excitation light cut filter 22, and then is imaged on the imaging surface of the high-sensitivity imaging device 24 by the first imaging optical system 23, and has high sensitivity. Images are taken at a predetermined frame rate by the image sensor 24.

  The mixed image signal sequentially output from the high-sensitivity imaging device 24 is subjected to CDS / AGC (correlated double sampling / automatic gain control) processing and A / D conversion processing in the imaging control unit 27, and then the cable 5 Are sequentially output to the image processing apparatus 3.

  The mixed image signal input to the image processing device 3 is temporarily stored in the fluorescence image input controller 32 and then stored in the memory 34. The mixed image signal for each frame read from the memory 34 is subjected to predetermined image processing in the mixed image processing unit 53 of the image processing unit 33 and then output to the reflected image acquisition unit 54.

  Then, in the reflection image acquisition unit 54, as shown in FIG. 7, the fluorescence image signal is subtracted from the input mixed image signal to acquire the reflection image signal. This reflected image signal is an image signal representing a peripheral portion obtained by subtracting only the light emitting portion of the fluorescent image from the mixed image.

  Then, the reflection image signal acquired by the reflection image acquisition unit 54 and the fluorescence image signal output from the fluorescence image processing unit 52 are output to the video output unit 35.

  Then, the video output unit 35 generates a composite image signal by assigning different colors to the input reflected image signal and fluorescent image signal, and performs a predetermined process on the composite image signal. A display control signal is generated, and the display control signal for each frame is sequentially output to the monitor 4. Then, the monitor 4 displays a composite image as shown in FIG. 7 based on the input display control signal.

  In the composite image, the light emitting portion of the fluorescent image and the peripheral portion thereof are displayed in different colors, and the state of the peripheral portion of the fluorescent portion can be observed.

  In addition, when the composite image is displayed by simultaneously irradiating the excitation light L2 and the fluorescence wavelength region illumination light L0 as in the above embodiment, if the amount of the fluorescence wavelength region illumination light L0 is too large, the fluorescence image becomes a reflected image. There is a possibility that it is buried and it is difficult to recognize the fluorescent part in the composite image.

  Therefore, the light amount of the fluorescence wavelength region illumination light may be adjusted based on the reflection image signal and the fluorescence image signal acquired above.

  Specifically, first, a fluorescent partial image signal of only the light emitting portion is extracted from the fluorescent image signal, and a reflected image signal is obtained by subtracting the fluorescent partial image signal from the mixed image signal as shown in FIG. Further, a reflected partial image signal corresponding to the fluorescent partial image signal is extracted from the reflected image signal.

Since the fluorescence image signal maintains a strong signal intensity with respect to the reflected image signal, for example, when the relationship between the fluorescent partial image signal and the reflected partial image signal satisfies the following expression (1), What is necessary is just to make it reduce the light quantity of wavelength range illumination light.
Fluorescent partial image signal−reflected partial image signal × 2 <0 (1)
If the following expression (2) is further satisfied, the amount of fluorescence wavelength region illumination light may be increased.
Fluorescent partial image signal−reflected partial image signal × 2> 0 (2)
By controlling so as to satisfy both the above expressions (1) and (2), the ratio of the signal intensity of the fluorescent image signal and the signal intensity of the reflected image signal can be kept constant.

  In addition, the constant 2 in the above formula (1) and the above formula (2) is not limited to this value, and may be one or more other values.

  Moreover, in the said embodiment, by irradiating excitation light continuously and irradiating fluorescence wavelength range illumination light in a pulse form, by the fluorescence image by irradiation of only excitation light, and irradiation of excitation light and fluorescence wavelength range illumination light A mixed image is acquired, a reflected image is acquired by subtracting a fluorescent image from the mixed image, and a composite image is generated using the reflected image and the fluorescent image. Then, the excitation light and the fluorescence wavelength region illumination light are alternately and repeatedly irradiated to obtain a fluorescence image by irradiation only with the excitation light and a reflection image by irradiation only with the fluorescence wavelength region illumination light. And a composite image may be generated.

  In the above embodiment, the fluorescent wavelength region illumination light is irradiated in a pulsed manner, but this is not limiting, and when the observer wants to observe the composite image, the fluorescent wavelength region illumination light is irradiated at an arbitrary timing. Then, a composite image may be generated in the same manner as in the above embodiment.

  In the above embodiment, the fluorescent image is captured by the first imaging system. However, the present invention is not limited to this, and an image based on the light absorption characteristics of the observed part by irradiating special light to the observed part is captured. You may make it do.

  Moreover, although the said embodiment applies the image acquisition apparatus of this invention to a rigid endoscope system, even if it applies to other endoscope systems which have a flexible endoscope apparatus, for example, it is not restricted to this. Good. Further, the present invention is not limited to an endoscope system, and may be applied to a so-called video camera type medical image capturing apparatus that does not include an insertion portion that is inserted into the body.

DESCRIPTION OF SYMBOLS 1 Rigid endoscope system 2 Light source device 3 Image processing apparatus 4 Monitor 10 Rigid endoscope imaging apparatus 20 Imaging unit 22 Excitation light cut filter 24 High sensitivity imaging element 26 Imaging element 30 Body cavity insertion part 33 Image processing part 35 Video output part 40 Normal light source 49 Illumination light LD light source 50 Driver 51 Normal image processing unit 52 Fluorescent image processing unit 53 Mixed image processing unit 54 Reflected image acquisition unit

Claims (7)

An excitation light irradiating unit that irradiates the observation part with excitation light; an imaging device that receives fluorescence emitted from the observation part by irradiation of the excitation light and captures a fluorescence image; and transmits the fluorescence and the excitation In an image imaging device including an imaging unit having an excitation light cut filter that cuts light in a wavelength band equal to or less than the wavelength of light,
A normal light irradiation unit that irradiates the observed portion with normal light having a wavelength different from that of the excitation light;
Illumination light that irradiates the observed part with illumination light having a wavelength different from that of the excitation light and the normal light and having a wavelength that is transmitted through the excitation light cut filter and within a sensitivity range of the imaging element. An image pickup apparatus comprising: an irradiation unit. An excitation light irradiating unit that irradiates the observation part with excitation light; an imaging device that receives fluorescence emitted from the observation part by irradiation of the excitation light and captures a fluorescence image; and transmits the fluorescence and the excitation In an image imaging device including an imaging unit having an excitation light cut filter that cuts light in a wavelength band equal to or less than the wavelength of light,
An illumination light irradiating unit that irradiates the observed part with illumination light having a wavelength that passes through the excitation light cut filter and within a sensitivity range of the imaging element;
The imaging unit receives fluorescence emitted from the observed part by irradiating the observed part with only the excitation light and captures a fluorescent image, and includes the excitation light and the illumination light. Receives the light emitted from the observed part by both irradiations and captures a mixed image,
Based on the mixed image and the special image, a reflected image acquisition unit that acquires a reflected image according to only reflected light by irradiation of the illumination light to the observed portion;
An image capturing apparatus comprising: a composite image acquisition unit that acquires a composite image obtained by combining the special image and the reflection image . And the excitation light emitter and the illumination light emitter is, independently of each other image capturing apparatus according to claim 1, wherein a is capable irradiating with the illumination light and the excitation light. When the signal intensity of the fluorescent image is smaller than a constant multiple of 1 or more of the signal intensity of the reflected image, an illumination light control unit is provided for controlling the illumination light irradiation unit so as to reduce the amount of illumination light. The image capturing apparatus according to claim 2, wherein The illumination light control unit controls the illumination light irradiation unit to increase the amount of the illumination light when the signal intensity of the fluorescent image is greater than one constant multiple of the signal intensity of the reflected image. The image capturing apparatus according to claim 4, wherein the apparatus is an image capturing apparatus. 2. The illumination light irradiating unit irradiates light having a wavelength substantially the same as a peak wavelength of fluorescence emitted from the observed portion by irradiation of the excitation light as the illumination light. 5. The image pickup device according to any one of 5 to 5 .   The imaging section receives the reflected light and the fluorescence received when the illumination light is applied to the observed part, and the imaging element receives the reflected light generated when the normal light is applied to the observed part. The image capturing apparatus according to claim 1, wherein the image capturing apparatus is provided separately.