JP2002065602A - Light optical system and enscopic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illuminating optical system conforming with an illuminating range of an R light and an excitation light and an endoscopic system equipped with this illuminating optical system. SOLUTION: Parallel light beam emitted from a white light source 21 is converted into the R light through an R filter of a wheel W after transmitting a dichroic mirror 24. A harvesting lens C allows this R light to enter a basic edge of a light guide 12 in the range of an α angle. The parallel light beam emitted from an excitation light source 22 is smaller in its diameter than that of the parallel light beam emitted from the white light source 21. Thus, the harvesting lens C allows the excitation light reflected from the dichroic mirror 24 to enter the basic edge of the light guide 12 in the range of a β angle (β<α). Since the wave length of the excitation light is shoter than the R light, the range γof an angle of the excitation light emitted from the light guide 12 is equal to that of the R light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination optical system for illuminating a subject with a plurality of types of light, and an endoscope apparatus provided with the illumination optical system.

[0002]

2. Description of the Related Art FIG. 14 is a block diagram of a conventional endoscope apparatus. This endoscope device includes an endoscope 70 and an external device 8.
0 is provided. The endoscope 70 has an objective lens 71 provided at the distal end thereof. The endoscope 70 has a light guide 72 made of a fiber bundle.
have. The light guide 72 has its distal end face facing a cover glass (not shown) provided at the distal end of the endoscope 70. And this light guide 72
Is drawn through the endoscope 70, and its proximal end is drawn into the external device 80.

Further, the endoscope 70 has an ultraviolet cut filter 73 and a CCD 74. When the distal end of the endoscope 1 is arranged to face the subject, the imaging surface of the CCD 74 is arranged near the position where the objective lens 71 forms an image of the subject. The ultraviolet cut filter 73 is inserted in the optical path between the objective lens 71 and the CCD 74.

[0004] The external device 80 includes a white light source 81 that emits white light as a parallel light beam, and an excitation light source 82 that emits a parallel light beam containing components in the ultraviolet band. The diameter of the parallel light flux emitted from the white light source 81 and the diameter of the parallel light flux emitted from the excitation light source 82 are equal to each other. On the optical path of the white light emitted from the white light source 81, an infrared cut filter 83, a first shutter 84, and a dichroic mirror 85 are sequentially arranged.

[0005] The infrared cut filter 83 includes a white light source 81.
Of the white light emitted from the infrared band, and transmits the visible band. The first shutter 84 blocks or allows white light transmitted through the infrared cut filter 83 to pass therethrough. The dichroic mirror 85 transmits a visible band component of the incident light and reflects an ultraviolet band component. Therefore, white light in the visible band that has passed through the first shutter 84 passes through the dichroic mirror 85.

The excitation light source 82 is disposed so that the emitted light is orthogonal to the optical path of the white light passing through the dichroic mirror 85 on the reflection surface of the dichroic mirror 85. On an optical path between the excitation light source 82 and the dichroic mirror 85, an excitation light filter 86 and a second shutter 87 are arranged in this order from the excitation light source 82 side. The excitation light filter 86 transmits only the component of the band used as the excitation light among the light emitted from the excitation light source 82. The excitation light is ultraviolet light that excites autofluorescence of a living body.

[0007] The second shutter 87 is provided with an excitation light filter 8.
Excitation light transmitted through 6 is blocked or passed. The excitation light passing through the second shutter 87 is reflected by the dichroic mirror 85. The optical path of the excitation light reflected by the dichroic mirror 85 is the same as the optical path of the white light transmitted through the dichroic mirror 85,
Match.

On the optical path after the dichroic mirror 85, a wheel 88 and a condenser lens C are arranged in this order. The wheel 88 is formed in a disk shape, and has four openings (not shown) formed in a ring-shaped portion along the outer periphery thereof. Each of these openings has a B filter that transmits only blue light (B light), a G filter that transmits only green light (G light), an R filter that transmits only red light (R light), and a transmission of excitation light. The transparent members to be used are each loaded. The wheel 88 is driven by a motor to rotate, and its B filter, G filter, and R filter are rotated.
The filter and the transparent member are repeatedly inserted into the optical path in order.

The B filter, G
While the filter or the R filter is inserted in the optical path, the first shutter 84 allows white light to pass, and the second shutter 87 blocks excitation light.
For this reason, only white light enters the dichroic mirror 85. Then, this white light is
Filter, G filter, and R filter sequentially
The light is converted into B light, G light, and R light, and travels to the condenser lens C.

On the other hand, while the transparent member of the wheel 88 is inserted in the optical path, the first shutter 84 blocks white light and the second shutter 87 allows excitation light to pass. . For this reason, only the excitation light enters the dichroic mirror 85. Then, the excitation light passes through the transparent member of the wheel 88 and is condensed by the condenser lens C.
Go to

The condenser lens C is an achromatic lens having a positive power. Then, the condenser lens C converges the incident light on the base end surface of the light guide 72.
Therefore, the B light, the G light, the R light
Light and excitation light sequentially and repeatedly enter. The incident light is
The light is guided by the light guide 72 and emitted from the front end surface. Therefore, when the distal end of the endoscope 1 is disposed to face the subject, the subject is repeatedly irradiated with the B light, the G light, the R light, and the excitation light in order.

When the subject is irradiated with B light, G light, or R light, the objective lens 71
An image of the subject is formed by the B light, the G light, or the R light in the vicinity of the imaging surface 74. These images are converted into image signals by the CCD 74. That is, the image of the subject by the B light, the image by the G light, and the image by the R light are respectively a B image signal,
It is converted into an image signal and an R image signal, respectively.

On the other hand, when the subject is irradiated with the excitation light, the subject emits autofluorescence.
For this reason, the auto-fluorescence emitted from the subject and the excitation light reflected on the subject surface enter the objective lens 71. This objective lens 71 is a CCD
An object image is formed in the vicinity of the imaging plane 74. However, since an ultraviolet cut filter 73 is inserted in the optical path between the objective lens 71 and the CCD 74, an image of the subject only with the autofluorescence is formed near the imaging surface of the CCD 74. The CCD 74 captures an image of the subject by autofluorescence,
It is converted into an image signal (F image signal).

Further, the external device 80 includes an image processing unit 91
have. The image processing section 91 is connected to the CCD 74 via a signal line. The image processing unit 91 sequentially and repeatedly acquires the B image signal, the G image signal, the R image signal, and the F image signal output from the CCD 74.

The image processing section 91 synthesizes color image data (normal image data) of the subject based on the acquired B image signal, G image signal, and R image signal. Further, the image processing section 91 generates fluorescent image data of the subject based on the F image signal.

Further, the image processing section 91 extracts a component corresponding to the R image signal from the normal image data and creates reference image data which is monochrome image data. Then, the image processing unit 91 extracts the specific image data by subtracting the reference image data from the fluorescent image data. The specific image data includes only information corresponding to a portion of the subject where autofluorescence is weak. Note that the intensity of the autofluorescence at the lesion portion in the living tissue is smaller than the intensity of the autofluorescence at the normal portion. Therefore, the specific image data includes information corresponding to the lesion part.

Further, the image processing section 91 superimposes the specific image data on the normal image data,
Generate diagnostic image data. The diagnostic image data is set such that, when displayed on the screen as a diagnostic image, a portion corresponding to the specific image data is displayed in a predetermined color such as blue.

[0018]

As described above, in the diagnostic image data, the information corresponding to the lesion is:
It is included in the specific image data. Therefore, in order to obtain diagnostic image data in which the position and shape of the lesion portion are accurately indicated, the position and shape of the lesion portion in the specific image data must be accurate.

Therefore, if the R image signal and the F image signal used for generating the specific image data do not correspond to each other correctly, an accurate specific image and diagnostic image cannot be obtained. For example, as shown below, if the illumination range of the R light emitted from the light guide and the illumination range of the excitation light are different from each other, an accurate specific image and diagnostic image can be obtained in a portion where these two illumination ranges do not overlap each other. Images cannot be obtained.

In the endoscope apparatus shown in FIG.
The light beam diameter of the parallel light beam (visible light) emitted from 1 and the light beam diameter of the parallel light beam (excitation light) emitted from the excitation light source 82 are equal to each other. Therefore, the condenser lens C
R incident on the light guide 72 while being converged by
The angle range of the light (B light, G light) and the angle range of the excitation light are equal to each other. That is, both the R light and the excitation light enter the light guide 72 within the range of the predetermined angle α.

Then, the R light guided by the light guide 72 is emitted from the front end surface within the range of the angle γ.
On the other hand, the excitation light guided by the light guide 72 is emitted from the distal end surface within the range of the angle δ. Since the wavelength of the excitation light is shorter than the wavelength of the R light, δ> γ. Therefore, the illumination range of the excitation light on the subject is
It becomes wider than the illumination range of the R light. Therefore, the conventional endoscope apparatus has a problem that an accurate diagnostic image cannot be obtained in a portion where the illumination range of the excitation light and the illumination range of the R light do not overlap.

It is therefore an object of the present invention to provide an illumination optical system that emits the illumination light so that the illumination ranges of a plurality of illumination lights having different wavelengths from each other are equal, and an endoscope apparatus including the illumination optical system. It is an object of the present invention.

[0023]

SUMMARY OF THE INVENTION An illumination optical system and an endoscope apparatus according to the present invention employ the following configuration to solve the above-mentioned problems.

That is, a light guide that has a fiber bundle and emits a light beam incident on the base end side from the distal end side, a first light source unit that emits a light beam in a predetermined first wavelength band, A second light source unit that emits a light beam in a second wavelength band shorter than the band, and one of the light beams emitted from both light source units is emitted toward the base end side of the light guide. An illumination optical system comprising: a switching mechanism; and a condensing lens that is inserted and disposed in an optical path between the light guide and the switching mechanism, and that converges light emitted from the switching mechanism to a base end side of the light guide. Wherein the first light emitted from the front end side of the light guide is
The light of the second wavelength band is diffused so that the range of the angle at which the light of the wavelength band is diffused and the range of the angle at which the light of the second wavelength band emitted from the front end of the light guide is diffused are equal to each other. A light flux adjusting unit that adjusts a range of angles at which the light in the light guide is incident is relatively smaller than a range of angles at which light in the first wavelength band enters the light guide. I do.

With this configuration, the angle range when the light of the second wavelength band enters the light guide is relatively smaller than the angle range when the light of the first wavelength band enters the light guide. Become smaller. For this reason, the angle range in which the light of the first wavelength band emitted from the front end of the light guide is diffused, and the second angle emitted from the front end of the light guide.
The range of angles at which light in the wavelength band is diffused becomes equal to each other. Therefore, the illumination range by the light of the first wavelength band and the illumination range by the light of the second wavelength band coincide with each other.

Each light source unit may emit a parallel light beam having a different diameter from each other. In this case, the larger the diameter of the parallel light beam incident on the condenser lens, the larger the range of angles when the light is emitted from the condenser lens and enters the light guide.

Further, a light beam adjusting unit for adjusting the diameter of the parallel light beam emitted from each light source unit may be provided. The light beam adjusting unit may be a light collecting optical system and a diverging optical system that adjust the diameter of the light beam, or may be a stop.

Note that a convergent light may be emitted from the light source instead of emitting a parallel light beam. In this case, the emitted convergent light is converted into a parallel light beam having a predetermined diameter by the diverging optical system. Further, instead of emitting a parallel light beam, divergent light may be emitted from the light source unit. In this case, the emitted divergent light is converted into a parallel light beam having a predetermined diameter by the condensing optical system.

Further, the first light source unit may emit visible light, and the second light source unit may emit excitation light that is ultraviolet light in a predetermined band for exciting autofluorescence of a living body. This illumination optical system is used for an endoscope apparatus for fluorescence observation.

This endoscope apparatus converges the illumination optical system and components other than the excitation light of the light from the surface of the object illuminated by the illumination optical system to form an image of the surface of the object. An objective optical system to be formed, an image pickup element that captures an image of the surface of the object formed by the objective optical system and converts the image into an image signal, and controls a switching mechanism in the illumination optical system to control the visible light and the excitation light. Light is alternately and repeatedly incident on the light guide, and normal image data is generated based on a portion of the image signal acquired by the image sensor corresponding to a period during which visible light is incident on the light guide. To generate fluorescence image data based on a portion corresponding to a period during which excitation light is incident on the light guide, obtain reference image data from the normal image data, and obtain The irradiation image data by subtracting from the fluorescence image data, extracts the specific image data,
A processor that generates diagnostic image data for displaying a moving image by superimposing the extracted specific image data on the normal image data.

With such a configuration, the illumination range of the subject is identical between the case using the visible light and the case using the excitation light, so that the reference image data and the fluorescence image data match exactly with each other. I have. Therefore, accurate specific image data and diagnostic images can be obtained.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An endoscope apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 1 is a structural view of an endoscope apparatus according to the present embodiment. As shown in FIG. 1, the endoscope device includes an endoscope 1 and an external device 2.

First, the endoscope 1 will be described. Although not shown in FIG. 1, the endoscope 1 has a flexible tubular insertion portion to be inserted into a living body, and an operation portion integrally connected to a base end side of the insertion portion. , And a flexible light guide tube for connecting the operation unit to the external device 2.

The distal end of the insertion portion of the endoscope 1 is sealed by a not-shown distal end made of a hard member. In addition, a bending mechanism (not shown) is incorporated in a predetermined region near the distal end of the insertion portion, and the region can be bent. The operation unit is provided with a dial for performing a bending operation of the bending mechanism and various operation switches.

The distal end of the endoscope 1 has at least 3
Two openings are opened, and two of the three openings are sealed by a cover glass (not shown), which is a transparent member having a parallel plate shape, and an objective lens (objective optical system) 11, respectively. . The other openings are used as forceps holes.

Further, the endoscope 1 has a light guide 12. The light guide 12 is a fiber bundle formed by bundling a number of optical fibers. The light guide 12 has its distal end face opposed to the cover glass, is drawn through the insertion section, the operation section, and the light guide flexible tube, and its base end is drawn into the external device 2.

Further, the endoscope 1 includes an excitation light cut filter 13 and a CCD (charge-coupl
ed device) 14. The imaging surface of the CCD 14 is arranged at a position where the objective lens 11 connects the subject image in a state where the distal end of the endoscope 1 is opposed to the subject. The excitation light cut filter 13
Is inserted and arranged in the optical path between the objective lens 11 and the CCD 14.

Next, the external device 2 will be described. FIG.
As shown in FIG. 2, the external device 2 includes a white light source 21 and an excitation light source 22. This white light source 21
It has a first lamp 211 for emitting white light and a first reflector 212. This first reflector 21
2, the inner surface (reflection surface) is formed as a paraboloid of revolution. Note that the lamp 211 is
At the focal point of the paraboloid of revolution.
The light emitted from the lamp 211 is reflected by the reflector 212 and emitted as a parallel light beam.

On the other hand, the excitation light source 22 includes a second lamp 221 for emitting light including ultraviolet light and a second reflector 2.
22. This second reflector 222
The inner surface (reflection surface) is formed as a paraboloid of revolution. Note that the second lamp 221 is connected to the reflector 22.
2 at the focal point of the paraboloid of revolution. The light emitted from the lamp 221 is reflected by the reflector 222 and emitted as a parallel light beam.

The diameter of the first reflector 212 is larger than the diameter of the second reflector 222. For this reason, the diameter of the parallel light beam emitted from the white light source 21 is larger than the diameter of the parallel light beam emitted from the excitation light source 22.

Further, the external device 2 includes the white light source 21
An infrared cut filter 23, a first shutter S1, and a dichroic mirror 24, which are respectively disposed on the optical path of the parallel light flux emitted from the optical system.

The infrared cut filter 23 is used for the white light source 21.
Of the white light emitted from the infrared band, and transmits the visible band. The first shutter S1 is connected to a first shutter driving mechanism S1a. The first shutter driving mechanism S1a drives the first shutter S1 to block or pass white light transmitted through the infrared cut filter 23. The dichroic mirror 24 transmits a visible band component of the incident light and reflects an ultraviolet band component. Therefore, white light in the visible band that has passed through the first shutter S1 passes through the dichroic mirror 24.

The excitation light source 22 is arranged so that the emitted light is orthogonal to the optical path of the white light passing through the dichroic mirror 24 on the reflection surface of the dichroic mirror 24. On the optical path between the excitation light source 22 and the dichroic mirror 24, an excitation light filter 25 and a second shutter S2 are arranged in this order from the excitation light source 22 side. The excitation light filter 25 transmits only the component of the band used as the excitation light among the light emitted from the excitation light source 22. The excitation light is ultraviolet light that excites autofluorescence of a living body.

The second shutter S2 is connected to a second shutter driving mechanism S2a. The second shutter drive mechanism S2a blocks or passes the excitation light transmitted through the excitation light filter 25 by driving the second shutter S2. The excitation light that has passed through the second shutter S2 is reflected by the dichroic mirror 24. The optical path of the excitation light reflected by the dichroic mirror 24 matches the optical path of the white light transmitted through the dichroic mirror 24. Each shutter S1, S2
The shutter driving mechanisms S1a and S2a and the dichroic mirror 24 correspond to a switching mechanism.

On the optical path after the dichroic mirror 24, a wheel W and a condenser lens C are arranged in this order. The wheel W is formed in a disk shape, and four openings (not shown) are opened in a ring-shaped portion along the outer periphery thereof. Each of these openings has a B filter that transmits only blue light (B light), a G filter that transmits only green light (G light), an R filter that transmits only red light (R light), and a transmission of excitation light. The transparent members to be used are each loaded. This wheel W is connected to a motor M. By rotating the wheel W, the motor M sequentially and repeatedly inserts the B filter, the G filter, the R filter, and the transparent member into the optical path.

During the period when the B, G, or R filter of the wheel W is inserted in the optical path, the first shutter S1 allows white light to pass, and the second shutter S2 activates the second shutter S2. Excitation light is blocked. For this reason, only white light enters the dichroic mirror 24. Then, the white light is sequentially transmitted to the B filter by the B filter, the G filter, and the R filter of the wheel W.
The light is converted into light, G light, and R light, and travels to the condenser lens C.

On the other hand, during the period when the transparent member of the wheel W is inserted into the optical path, the first shutter S1 blocks white light and the second shutter S2 allows excitation light to pass. . For this reason, dichroic mirror 2
4, only the excitation light is incident. Then, the excitation light passes through the transparent member of the wheel W and travels to the condenser lens C.

The condenser lens C converges the incident light on the base end surface of the light guide 12. Therefore, the B light, the G light, the R light, and the excitation light sequentially and repeatedly enter the light guide 12. The incident light is reflected by the light guide 12.
And emitted from the endoscope distal end toward the subject. Therefore, the subject is sequentially and repeatedly irradiated with the B light, the G light, the R light, and the excitation light.

The visible light (B light, G light, and R light) transmitted through the dichroic mirror 24 is converged by the condenser lens C and has a predetermined angle α within the opening angle of the light guide 12 due to the R light. Within the range of the light guide 12. On the other hand, since the light beam diameter of the excitation light reflected by the dichroic mirror 24 is smaller than the light beam diameter of the visible light, it is incident on the light guide 12 within a predetermined angle β smaller than the angle α.

The R light guided by the light guide 12 is emitted from the light guide 12 while diffusing within a range of a predetermined angle γ. On the other hand, this light guide 12
Is also emitted from the light guide 12 while diffusing within the range of the angle γ.

Assuming that the excitation light also enters the light guide 12 within the range of the angle α in the same manner as the R light, the excitation light has a wavelength shorter than that of the R light and thus spreads more than the angle γ. The light is emitted from the lever light guide 12. However, in practice, the angle range in which the excitation light is incident on the light guide 12 is set smaller than the angle range in which the R light is incident on the light guide 12, so that both the excitation light and the R light have the angle γ. The light is emitted from the light guide 12 within the range.

When B light, G light, or R light is emitted from the light guide 12 to the subject, the objective lens 11 of the endoscope 1 is positioned near the imaging surface of the CCD 14.
An image is formed by the B light, the G light, or the R light of the subject. These images are converted by the CCD 14 into image signals. That is, the image of the subject using the B light, the image using the G light, and the image using the R light are converted into a B image signal, a G image signal, and an R image signal, respectively.

On the other hand, when the excitation light is emitted from the light guide 12 to the subject, the subject emits autofluorescence (green light band). Therefore, the auto-fluorescence emitted from the subject and the excitation light reflected on the subject surface enter the objective lens 11. The excitation light cut filter 13 blocks components of the band of the excitation light in the convergent light emitted from the objective lens, and transmits the autofluorescence. The auto-fluorescence transmitted through this excitation light cut filter 13
An object image is formed in the vicinity of the imaging surface 14. This CCD 14
Converts an image of the subject by autofluorescence into an image signal (F image signal).

Further, the external device 2 has a control unit 27 and an image processing unit 28 connected to each other. In addition,
The control unit 27 and the image processing unit 28 correspond to a processor. The control unit 27 controls each shutter driving mechanism S1a,
S2a and the motor M, respectively. Then, the controller 27 controls the motor M to rotate the wheel W at a constant speed. The image processing unit 28 is connected to the CCD 14, and acquires and processes an image signal output from the CCD 14.

FIG. 2 is a schematic block diagram showing the configuration of the image processing section 28. As shown in FIG. 2, the image processing unit 28 includes an amplifier 281, an A / D converter 282,
Normal image memory 283 and fluorescent image memory 284
Is provided.

The amplifier 281 amplifies the B image signal, the G image signal, and the R image signal transmitted from the CCD 14 at a predetermined normal amplification factor. The amplified signal is A / D
The data is A / D-converted by the converter 282 and stored in the normal image memory 283 as normal image data. This normal image data is stored in the normal image memory 283 as color image data corresponding to a predetermined number of pixels.

On the other hand, the amplifier 281 amplifies the F image signal transmitted from the CCD 14 at a predetermined fluorescence amplification factor. The amplified signal is A / D converted by the A / D converter 282 and stored in the fluorescent image memory 284 as fluorescent image data. Since the F image signal is weaker than the other image signals, the fluorescence amplification factor is set to be larger than the normal amplification factor. The fluorescent image data is stored in the fluorescent image memory 284 as monochrome image data corresponding to a predetermined number of pixels.

Further, the image processing section 28 includes an image comparator 285, an image mixing circuit 286, and a D / A converter 28.
7 and an encoder 288. The image comparator 285 is connected to the normal image memory 283 and the fluorescent image memory 284, respectively. Then, the image comparator 285 extracts, from the normal image data in the normal image memory 283, a portion corresponding to the R image signal in the normal image data as reference image data. This reference image data is extracted as monochrome image data corresponding to a predetermined number of pixels.

Further, the image comparator 285 obtains the fluorescent image data in the fluorescent image memory 284 and subtracts the reference image data from the fluorescent image data to obtain
Generate specific image data. This specific image data includes
Only the information corresponding to the part that is likely to be a lesion (weak autofluorescence) in the subject is included.

The image mixing circuit 286 has the normal image memory 2
83 and the image comparator 285, respectively.
The image mixing circuit 286 is provided in the normal image memory 2
The normal image data in 83 and the specific image data generated in the image comparator 285 are acquired. further,
The image mixing circuit 286 generates and outputs diagnostic image data by superimposing the specific image data on the normal image data as a predetermined color (for example, blue).

The D / A converter 287 is connected to the image mixing circuit 286. The D / A converter 287 outputs a diagnostic image signal by performing D / A conversion on the diagnostic image data output from the image mixing circuit 286.

The encoder 288 is connected to the D / A converter 287 and to a display device D such as a television monitor or a personal computer. The encoder 288 has a D / A
The diagnostic image signal output from the converter 287 is obtained, and a signal for displaying a screen (a synchronization signal or the like) on the display device D is added to the diagnostic image signal and output. The display device D displays a moving image of the signal output from the encoder 288 as a diagnostic image. The display device D may display a normal image based on the normal image data as a moving image in a state where the normal image is aligned with the diagnostic image.

FIG. 3 is a schematic diagram of a normal image represented by normal image data stored in the normal image memory 283. FIG. 4 is a schematic diagram of a fluorescent image indicated by the fluorescent image data stored in the fluorescent image memory 284.
In these normal images and fluorescent images, the lumen Ta is shown dark because it is shaded, and the tube wall Tb is shown bright. Further, the fluorescent image of FIG. 4 shows a lesion portion Tc having weak autofluorescence on the tube wall Tb.

The reference image data extracted from the normal image data is data composed of the components of the R image signal in the normal image data. Therefore, FIG. 3 is also a schematic diagram of a reference image indicated by the reference image data. However, in practice, the normal image data is color image data, whereas the reference image data is monochrome image data.

FIG. 5 is a schematic diagram of a specific image indicated by specific image data output from the image comparator 285. This specific image (FIG. 5) is obtained by subtracting the reference image (FIG. 3) from the fluorescent image (FIG. 4).
As shown in FIG. 5, the specific image includes a lesion portion T
c, but not the healthy part of the tube wall Tb and the lumen Ta.

FIG. 6 is a schematic diagram of a diagnostic image represented by diagnostic image data output from the image mixing circuit 286. This diagnostic image (FIG. 6) is a normal image (FIG. 3)
Then, the specific image (FIG. 5) is obtained by superimposing. In this diagnostic image, the lesion portion Tc is colored blue or the like. For this reason, the surgeon observes the diagnostic image displayed on the screen of the display device D,
The position and shape of the lesion part Tc can be accurately recognized.

As described above, in the endoscope apparatus of the present embodiment, the diameter of the light beam emitted from the white light source 21 and the diameter of the light beam emitted from the excitation light source 22 are emitted from the light guide 12. The divergence angle of the R light and the divergence angle of the excitation light are set to be equal to each other. Therefore, the illumination range of the R light and the illumination range of the excitation light on the subject are equal to each other. Therefore, the reference image based on the R image signal and the fluorescent image based on the F image signal are subject images illuminated in the same illumination range. Therefore, since the noise derived from the difference in the illumination range is not mixed into the specific image data, an accurate diagnostic image can be obtained.

<Second Embodiment> FIG. 7 is a configuration diagram of an illumination optical system in the endoscope apparatus of the present embodiment. The endoscope apparatus according to the present embodiment is different from the endoscope apparatus according to the first embodiment in that an excitation light source 31 according to the present embodiment and a light flux adjusting unit 32 are provided instead of the excitation light source 22. Features.

The excitation light source 31 includes a second lamp 311, which emits light including ultraviolet light, and a second reflector 31.
Two. The second reflector 312 is formed in the same shape as the first reflector 212. The second lamp 311 is arranged at the focal point on the paraboloid of revolution of the reflector 312. The light emitted from the lamp 311 is reflected by the reflector 312 and emitted as a parallel light beam. For this reason, the diameter of the parallel light beam emitted from the excitation light source 31 is equal to the diameter of the parallel light beam emitted from the white light source 21.
Match.

The luminous flux adjusting unit 32 includes a positive lens 321 and a negative lens 322 arranged on the optical path between the excitation light source 31 and the excitation light filter 25 in order from the side close to the excitation light source 32.
have. The positive lens 321 and the negative lens 32
Numerals 2 are arranged so that their focal positions coincide with each other, and constitute an afocal optical system. The positive lens 321 corresponds to a diverging optical system, and the negative lens 322 corresponds to a converging optical system.

Then, the parallel light beam emitted from the excitation light source 31 is converged by the positive lens 321. The convergent light emitted from the positive lens 321 enters the negative lens 322, and is converted into a parallel light beam by the negative lens 322. Note that the diameter of the parallel light flux emitted from the negative lens 322 is larger than the diameter of the parallel light flux emitted from the excitation light source 31.
It is getting smaller.

The excitation light filter 25 includes the negative lens 32
Only the excitation light component of the parallel light flux emitted from 2 is transmitted. When the excitation light emitted from the excitation light filter 25 passes through the second shutter S2, it is reflected by the dichroic mirror 24 and travels toward the wheel W. The excitation light incident on the wheel W passes through the transparent member and travels to the condenser lens C.

The beam diameter of the excitation light incident on the condenser lens C is smaller than the beam diameter of the R light (G light, B light). For this reason, the angle range of the excitation light incident on the light guide 12 is smaller than the angle range of the R light. That is, the R light is
The excitation light is incident on the light guide 12 within the range of the angle α, while the excitation light is incident on the light guide 12 within the range of the angle β (α> β). Note that these α and β are the first
This is the same as in the embodiment. Therefore, the light guide 1
The range of the angle (γ) of the R light emitted from the light guide 2 coincides with the range of the angle (γ) of the excitation light emitted from the light guide 12.

FIG. 8 is an explanatory diagram of the light beam adjusting unit 32.
In the above description, the positive lens 321 and the negative lens 322 of the light flux adjusting unit 32 are set so as to form an afocal optical system. However, the positive lens 321 and the negative lens 322 may be able to approach or separate from each other. When the two lenses 321 and 322 come close to each other, the diameter of the light beam emitted from the negative lens 322 increases. On the other hand, when the lenses 321 and 322 are separated from each other, the diameter of the light beam emitted from the negative lens 322 becomes smaller.

FIG. 8A shows the light beam adjusting unit 32 in the state shown in FIG. When the two lenses 321 and 322 approach each other from the state shown in FIG. 8A, the state shown in FIG. In the case of FIG. 8B, the diameter of the light beam emitted from the light beam adjusting unit 32 is larger than in the case of FIG. 8A.
As the diameter of the emitted light beam increases, the range of the angle of incidence on the light guide 12 also increases. That is, θa <θb.

On the contrary, from the state shown in FIG.
When the two lenses 321 and 322 separate from each other, the state shown in FIG. In the case of FIG. 8 (c), the diameter of the light beam emitted from the light beam adjusting unit 32 is smaller than in the case of FIG. 8 (a). As the diameter of the emitted light beam decreases, the range of the angle of incidence on the light guide 12 also decreases. That is, θa> θc.

Therefore, the designer or the user adjusts the distance between the two lenses 321 and 322 in the light beam adjusting unit 32 to change the angle range of the excitation light emitted from the light guide 12 from the light guide 12. R injected
It can match the range of the angle of light.

When the user removes the endoscope 1 from the external device 2 and attaches another endoscope,
By changing the setting of the light flux adjusting unit 32 in accordance with the characteristics of the light guide of the new endoscope, the angle range of the excitation light emitted from the light guide is changed to the angle of the R light emitted from the light guide. Can be matched with range.

The light beam adjusting section 32 of the second embodiment has the positive lens 321 and the negative lens 322 as described above. The negative lens 322 of the light flux adjusting unit 32 may be a negative lens group including a plurality of lenses. With this configuration, the negative lens group is replaced with the positive lens 321.
And the relative distance between the plurality of lenses in the negative lens group changes, so that the light beam emitted from the light beam adjusting unit 32 changes its diameter while maintaining a parallel light beam. It can also be adjusted.

<Third Embodiment> An endoscope apparatus according to the present embodiment has the same structure as the endoscope apparatus according to the second embodiment.
A feature is that an excitation light source 41 according to the present embodiment and a light beam adjusting lens 42 as a light beam adjustment unit are provided instead of the excitation light source 31 and the light beam adjustment unit 32. FIG.
FIG. 3 is an explanatory diagram of the excitation light source 41 and the light beam adjusting lens 42.

The excitation light source 41 has a lamp 411 for emitting light including ultraviolet light and a reflector 412. The reflector 412 is a concave mirror, and its inner surface (reflection surface) is formed as an elliptical surface. When the ellipsoid is bisected perpendicular to the major axis direction, the ellipsoid has a surface shape of one of the divided ellipsoids.
Match. Note that the lamp 411 is disposed at a position (one focal point) closer to the reflector 412 among a pair of focal points of an ellipsoid corresponding to the elliptical surface of the reflector 412.

The light beam adjusting lens 42 is a negative lens (diverging optical system), and is arranged so that its rear focal point coincides with the other focal point of the ellipsoid corresponding to the reflecting surface of the reflector 412. The divergent light emitted from the lamp 411 is reflected by the reflector 412 toward the other focal point, and is emitted as convergent light. This convergent light is converted by the light flux adjusting lens 42 into parallel light. The diameter of the parallel light beam emitted from the light beam adjusting lens 42 is equal to the light beam adjusting unit 32 (FIG. 7) in the second embodiment.
And the diameter of the parallel luminous flux emitted from.

<Fourth Embodiment> An endoscope apparatus according to the present embodiment has the same structure as the endoscope apparatus according to the second embodiment.
The present embodiment is characterized in that an excitation light source 51 and a light flux adjustment unit 52 according to the present embodiment are provided instead of the excitation light source 31 and the light flux adjustment unit 32. FIG. 10 shows these excitation light sources 5.
FIG. 3 is an explanatory diagram of a light flux adjusting unit 52;

The excitation light source 51 has a lamp 511 for emitting light including ultraviolet light and a reflector 512. The reflector 512 is a concave mirror whose inner surface (reflection surface) is formed as a spherical surface. The lamp 511 is arranged at the center of the spherical surface of the reflector 512.

The light beam adjusting section 52 has a positive lens 521 and a negative lens 522. The positive lens 521 and the negative lens 522 are arranged such that their optical axes coincide with the optical axis of the reflector 512. The positive lens 52
1 is disposed on the front side of the negative lens 522. The positive lens 521 and the negative lens 522 are converging optical systems having a total positive power.

The divergent light emitted from the lamp 511 is reflected by the reflector 512 toward the lamp 511. The divergent light diverging through the position of the lamp 511 is converged by the positive lens 521 and travels to the negative lens 522. The negative lens 522 converts the incident convergent light into parallel light and emits it. The diameter of the parallel light beam emitted from the negative lens 522 matches the diameter of the parallel light beam emitted from the light beam adjusting unit 32 (FIG. 7) in the second embodiment.

<Fifth Embodiment> An endoscope apparatus according to the present embodiment has the same structure as the endoscope apparatus according to the second embodiment.
It is characterized in that an excitation light source 61 according to the present embodiment and a light beam adjusting lens 62 as a light beam adjustment unit are provided instead of the excitation light source 31 and the light beam adjustment unit 32. FIG.
FIG. 4 is an explanatory diagram of the excitation light source 61 and the light beam adjusting lens 62.

The excitation light source 61 has a lamp 611 that emits light including ultraviolet light, and a reflector 612. The reflector 612 is a concave mirror whose inner surface (reflection surface) is formed as a spherical surface. Note that the lamp 611 is disposed at the center of the spherical surface of the reflector 612.

The light beam adjusting lens 62 is a positive lens (converging optical system), and is disposed with its front focal point coincident with the position of the lamp 611. Then, the divergent light emitted from the lamp 611 is reflected by the reflector 612 toward the lamp 611. The divergent light that has diverged after passing through the position of the lamp 611 is converted by the light flux adjusting lens 62 into parallel light. The diameter of the parallel light beam emitted from the light beam adjusting lens 62 is equal to the diameter of the parallel light beam emitted from the light beam adjusting unit 32 (FIG. 7) in the second embodiment.
Match.

<Modification> The endoscope apparatus according to this modification is
The configuration of the endoscope apparatus of each of the above embodiments is characterized in that the light guide 12 includes a light distribution lens 15. In the above embodiments, the illumination light emitted from the light guide 12 is transmitted through the cover glass (not shown) and emitted toward the subject. Instead of the cover glass, the end of the endoscope according to this modification is
The light distribution lens 15 shown in FIG.

The light distribution lens 15 is a lens having a negative power, and is provided at the distal end of the endoscope 1. The front end face of the light guide 12 faces the light distribution lens 15. The divergent light emitted from the distal end surface of the light guide 12 is further diffused by the light distribution lens 15 to irradiate the subject.

If the range of the angle at which the excitation light (UV) is incident on the base end face of the light guide 12 and the range of the angle at which the R light is incident are equal to each other, the light is emitted from the front end face of the light guide 12. The range of the angle of the excitation light is larger than the range of the angle of the R light.

When the light distribution lens 15 is formed by a single negative lens, its chromatic aberration of magnification must be considered. In this case, since the excitation light has a shorter wavelength than the R light, it is diffused by the light distribution lens 15 with a stronger power than the R light. For this reason, the designer needs to set the light beam diameter of the excitation light incident on the condenser lens C (FIGS. 1 and 7) smaller than in each of the above-described embodiments. With this setting, the angle range of the excitation light incident on the base end face of the light guide 12 is further narrowed, and the light distribution lens 15
The illumination range by the excitation light and the illumination range by the R light coincide with each other.

Further, as shown in FIG. 13, the second condenser lens 16 may be arranged to face the base end face of the light guide 12. When the second condenser lens 16 is formed of a positive single lens, its chromatic aberration of magnification must be considered. In this case, since the excitation light has a shorter wavelength than the R light, the second condenser lens 16
Converges with a stronger power than the R light.

If the excitation light and the R light enter the second condenser lens 16 in the same angle range, the light guide 12
The angle range of the excitation light incident on the base end surface is larger than the angle range of the R light. For this reason, the designer needs to set the diameter of the luminous flux of the excitation light incident on the condenser lens C (FIGS. 1 and 7) even smaller. When set like this,
Illumination range by the excitation light emitted from the light distribution lens 15,
And the illumination range by the R light coincide with each other.

[0097]

According to the illumination optical system of the present invention configured as described above, the range of the angle at which the light of the first wavelength band is diffused from the tip of the light guide depends on the light of the second wavelength band from the tip of the light guide. It matches the range of the diverging angle. For this reason, the illumination range by the light of the first wavelength band and the illumination range by the second wavelength band coincide with each other. According to the endoscope apparatus of the present invention, the visible light and the excitation light of the illumination optical system are changed. Since the illumination ranges coincide with each other, an accurate diagnostic image can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an endoscope apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic block diagram illustrating a configuration of an image processing unit.

FIG. 3 is a schematic diagram of a normal image and a reference image.

FIG. 4 is a schematic diagram of a fluorescent image.

FIG. 5 is a schematic diagram of a specific image.

FIG. 6 is a schematic diagram of a diagnostic image.

FIG. 7 is a configuration diagram of an endoscope apparatus according to a second embodiment of the present invention.

FIG. 8 is an explanatory diagram of a light beam adjusting unit according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram of an illumination optical system according to a third embodiment of the present invention.

FIG. 10 is an explanatory diagram of an illumination optical system according to a fourth embodiment of the present invention.

FIG. 11 is an explanatory diagram of an illumination optical system according to a fifth embodiment of the present invention.

FIG. 12 is an explanatory diagram of a modification including a light distribution lens.

FIG. 13 is an explanatory view of a modification including a second condenser lens.

FIG. 14 is a configuration diagram of a conventional endoscope device.

[Explanation of symbols]

 Reference Signs List 1 endoscope 11 objective lens 12 light guide 13 ultraviolet cut filter 14 CCD 2 external device 21 white light source 22 excitation light source 24 dichroic mirror 27 control unit 28 image processing unit 32 light flux adjustment unit 42 light flux adjustment lens 52 light flux adjustment unit 62 light flux adjustment Lens S1 First shutter S2 Second shutter C Condensing lens D Display

Claims (8)

[Claims] 1. A light guide having a fiber bundle and emitting a light beam incident on a proximal end thereof from the distal end side, a first light source unit emitting a light beam of a predetermined first wavelength band, and the first wavelength. A second light source unit that emits a light beam in a second wavelength band shorter than the band, and one of the light beams emitted from both light source units is emitted toward the base end side of the light guide. A switching mechanism, and inserted and arranged in an optical path between the light guide and the switching mechanism;
A converging lens for converging the light emitted from the switching mechanism to the base end of the light guide, wherein the light of the first wavelength band emitted from the front end of the light guide is diffused. The light of the second wavelength band is incident on the light guide such that the range of the angle of the light guide and the range of the angle of diffusion of the light of the second wavelength band emitted from the front end side of the light guide are equal to each other. When the angle range of the first
An illumination optical system, comprising: a light flux adjusting unit that adjusts a light in a wavelength band to be relatively smaller than an angle range when the light enters the light guide. 2. The light beam adjusting section adjusts a light beam of a second wavelength band incident on the condenser lens to be smaller than a light beam of a first wavelength band incident on the condenser lens. The illumination optical system according to claim 1, wherein: 3. Each of the light source units emits a parallel light beam, and the light beam adjusting unit includes a condensing optical system disposed on an optical path between one of the light source units and the switching mechanism. 3. A divergence optical system, wherein a diameter of an incident parallel light beam is enlarged or reduced and emitted.
Illumination optical system as described. 4. One of the two light source units emits convergent light; the other of the two light source units emits a parallel light beam; A diverging optical system disposed on an optical path between one of the switching mechanisms and emitting the converging light as a parallel light beam having a diameter different from that of the parallel light beam emitted from the other of the two light source units; The illumination optical system according to claim 1, wherein: 5. One of the two light source units emits divergent light, the other of the two light source units emits a parallel light beam, and the light beam adjusting unit includes: A convergence optical system disposed on the optical path between one of the switching mechanisms and emitting the incident divergent light as a parallel light beam having a diameter different from the diameter of the parallel light beam emitted from the other of the two light source units; The illumination optical system according to claim 1, wherein: 6. The first light source unit emits visible light, and the second light source unit emits excitation light that is ultraviolet light in a predetermined band for exciting autofluorescence of a living body. The illumination optical system according to claim 1. 7. An illumination optical system according to claim 6, further comprising: converging components other than excitation light of light from the surface of the object illuminated by the illumination optical system to form an image of the surface of the object. An objective optical system, an imaging element that captures an image of the surface of the subject formed by the objective optical system and converts the image into an image signal, and controls a switching mechanism in the illumination optical system to control the visible light and the excitation light. Are alternately and repeatedly incident on the light guide, and normal image data is generated based on a portion of the image signal acquired by the imaging device corresponding to a period during which visible light is incident on the light guide. Generate and generate fluorescence image data based on the portion corresponding to the period during which the excitation light is incident on the light guide,
By acquiring reference image data from the normal image data, by subtracting the acquired reference image data from the fluorescent image data, specific image data is extracted, and the extracted specific image data is superimposed on the normal image data. And a processor for generating diagnostic image data for displaying a moving image. 8. The endoscope apparatus according to claim 7, further comprising a display device for displaying a moving image of the image data generated by said processor.