JP2009297290A - Endoscope apparatus and image processing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endoscope apparatus permitting observation by selectively applying white light and the light in a specific narrow visible wavelength range by simple structure while narrowing the diameter of an insertion part of an endoscope and suppressing the heat generation of LED elements disposed at the distal end of the insertion part of the endoscope; and to provide an image processing method permitting more accurate spectrum diagnosis based on the image information from the endoscope apparatus. <P>SOLUTION: The endoscope apparatus comprises a first illumination optical system 61 and a second illumination optical system 61 comprising light emitting elements 71 and 73 disposed at the distal end of the insertion part 13 of the endoscope to emit light in the specific visible wavelength range. The first illumination optical system 61 comprises: a first light source 33 for emitting laser light; an optical fiber 21 for transmitting the incident laser light on the incident light side to the distal end of the insertion part of the endoscope; and a wavelength changing member 45 disposed on the light emission side of the optical fiber 21 and including at least one fluorescent material excited to emit light by the laser light. The first illumination optical system 61 mixes the laser light with the excited emission light from the wavelength changing member 45 to emit white light from the distal end of the insertion part 13 of the endoscope. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an endoscope apparatus and an image processing method thereof.

An endoscope apparatus that has been widely used conventionally guides illumination light from a lamp in a light source device by a light guide provided along an endoscope insertion portion, and the illumination light guided by the light guide. Is emitted from the illumination window at the tip of the endoscope insertion portion to illuminate the region to be inspected. On the other hand, some which used the LED element instead of the lamp | ramp as a light source are proposed (for example, patent document 1, 2).
In the light source device of Patent Document 1, LED elements are arranged at or near the operation portion of the endoscope, and light is output from the distal end of the endoscope insertion portion through a light guide that is an optical fiber bundle. Further, in the light source device described in Patent Document 2, an LED element is disposed at the tip of the endoscope insertion portion, and emits light only at the time of flash photography, and usually emits light from a xenon light source supplied through a light guide. I am doing so.
In addition to the LED element, there is one that performs illumination with laser light. The light source device of Patent Document 3 is configured to irradiate white illumination light by guiding blue laser light to the distal end of the endoscope insertion portion by an optical fiber and exciting and emitting a phosphor disposed at the distal end of the optical fiber.

By the way, in the endoscopic diagnosis, there is a technique called spectroscopic diagnosis using an image illuminated with light of a specific wavelength band in addition to the observation with the white illumination light described above. In that case, light of a specific narrow wavelength band is used as illumination light. In spectroscopic diagnosis, for example, neovascularization that occurs in the mucosa layer or submucosa can be clearly observed, and it is possible to describe the fine structure of the mucosal surface that cannot be obtained with normal observation images. This is useful for early detection. Illumination light in a specific wavelength band used for spectroscopic diagnosis has stronger scattering characteristics as the wavelength is shorter, so information from a relatively shallow layer can be obtained at a short wavelength and information from a relatively deep layer can be obtained at a long wavelength. . Therefore, in the case of observing the surface fine structure by limiting the depth of light to the surface layer, it is important to narrow the band of the illumination light in order to improve the contrast of the captured image.
JP-A-5-146403 JP 2002-219102 A JP 2005-205195 A

By the way, when diagnosing the upper gastrointestinal tract using an endoscope, a nasal endoscope that is less burdensome for a patient is being used instead of a conventional oral endoscope. However, in a configuration using a general lamp and a light guide, or as disclosed in Patent Document 1, an LED element is arranged in an operation part of an endoscope, and light emitted from the LED element is transmitted from the operation part to the endoscope tip part. In the configuration in which light is guided through, there is a limit to reducing the diameter of the endoscope insertion portion. That is, when the light source is a general lamp, it is difficult to reduce the illumination light to a small size. When the LED is an LED, the area of the light source is small compared to a general lamp, but high brightness is obtained. Since the area of the light emitting surface increases, the diameter cannot be reduced. In addition, there is a loss of light when light emitted from the light source is introduced into the light guide, which is disadvantageous in that light transmission efficiency (utilization efficiency) is reduced.
Moreover, when an LED element is disposed at the tip of the endoscope insertion portion as in Patent Document 2, a light guide is not necessary. However, in order to obtain a predetermined amount of light for white illumination, the heat generated from the LED element is very large to generate electrical light from blue and to generate phosphor light from blue. However, it has been difficult to sufficiently dissipate heat in a compact configuration. In particular, a transnasal endoscope has a thin endoscope insertion portion, and it is difficult to ensure the thickness of the light guide. Therefore, in order to secure a sufficient amount of illumination, the amount of light per unit area may be increased, but this is not preferable because heat generation increases. For this reason, the LED element arranged at the tip of the endoscope insertion part is used in combination with the illumination light supplied from the light source device through the light guide to emit light with low brightness, or only for strobe shooting that is temporarily lit. Usage conditions were limited, such as use.
Furthermore, as disclosed in Patent Document 3, heat generated by converting electric energy into blue excitation by guiding laser light through a thin optical fiber is not the tip but external, and the tip excites the phosphor from the blue excitation light. Although only the heat generated by the light emission can be achieved, the diameter of the endoscope insertion portion can be reduced, but when the laser light is converted into white light by the phosphor, a desired light emission wavelength width can be obtained, particularly light emission with a narrow wavelength width. It was difficult to get. Further, when laser light is directly used as illumination light, noise may be superimposed on a captured image due to speckle (interference) or flicker may easily occur in a moving image because of its high coherency.

  The present invention has been made in view of such a situation. The diameter of the endoscope insertion portion is reduced, and the generation of the LED element disposed at the distal end of the endoscope insertion portion is suppressed, while white light is specified. Endoscope device capable of selectively irradiating and observing light with a narrow visible wavelength band with a simple configuration, and more accurate spectroscopic diagnosis based on image information from this endoscope device An object of the present invention is to provide an image processing method.

The present invention has the following configuration.
(1) A first light source that emits laser light, an optical fiber that transmits the laser light to the light incident side and transmits it to the distal end of the endoscope insertion portion, and is arranged on the light emitting side of the optical fiber and is excited by the laser light A wavelength conversion member including at least one type of fluorescent material that emits light, and the laser light and excitation light emitted from the wavelength conversion member are mixed to emit white light from the distal end of the endoscope insertion portion. A first illumination optical system;
A second illumination optical system provided with a light emitting element disposed at the distal end of the endoscope insertion portion and emitting light in a specific visible wavelength band;
An endoscope apparatus comprising:

According to this endoscope apparatus, the laser light from the first light source is guided by the optical fiber, irradiated to the wavelength conversion member disposed at the output end of the optical fiber, and the wavelength conversion member is excited to emit light. White light is generated by the laser light from one light source and the excitation light, and an optical system for white light illumination is obtained. In addition, by providing the second illumination optical system having a light emitting element that emits light in a specific visible wavelength band, white light illumination and illumination with light in a specific visible wavelength band are selectively emitted with a simple configuration. Can be made.
Since white illumination light is generated using laser light, high-luminance light is obtained, and the diameter of the endoscope insertion portion is reduced in order to guide the light through the optical fiber.

(2) The endoscope apparatus according to (1),
An endoscope apparatus in which the light emitting element of the second illumination optical system is an LED element.

  According to this endoscope apparatus, light with high efficiency and high luminance can be obtained. Moreover, by using together with the laser light of the first illumination optical system, the light quantity of the LED element from the distal end of the endoscope insertion portion can be suppressed, thereby reducing the size of the distal end of the endoscope insertion portion and suppressing heat generation. Figured.

(3) The endoscope apparatus according to (1) or (2),
An endoscope apparatus in which the second illumination optical system includes a plurality of light emitting elements that emit light at different center wavelengths.

  According to this endoscope apparatus, by providing a plurality of light emitting elements, various illumination lights can be emitted according to the observation purpose.

(4) The endoscope apparatus according to any one of (1) to (3),
An endoscope apparatus in which the second illumination optical system includes a light emitting element that emits at least green light.

  According to this endoscope apparatus, it is possible to generate an emphasized image in spectroscopic diagnosis by emitting green light.

(5) The endoscope apparatus according to any one of (1) to (4),
An endoscope apparatus in which the second illumination optical system includes a light emitting element that emits at least blue light.

  According to this endoscope apparatus, it is possible to generate an enhanced image in spectroscopic diagnosis by emitting blue light.

(6) The endoscope apparatus according to any one of (1) to (5),
An endoscope apparatus in which the second illumination optical system includes a light emitting element that emits at least red light or infrared light.

  According to this endoscope apparatus, by emitting red light or infrared light, it is possible to perform so-called infrared light observation in which a medicine that easily absorbs infrared light is observed in a state of being intravenously injected.

(7) The endoscope apparatus according to any one of (1) to (6),
An imaging means including an imaging element that receives light from a site to be observed through an observation window provided at a distal end of the endoscope insertion unit and outputs an imaging signal;
Illumination light control means for switching and illuminating white light by the first illumination optical system and light of a specific visible wavelength band by the second illumination optical system;
An endoscopic apparatus comprising:

  According to this endoscope apparatus, the diameter of the endoscope insertion portion can be reduced, and the emitted light can be selectively controlled to emit white light and light in a specific visible wavelength band. Can be easily performed.

(8) The endoscope apparatus according to (7),
A first memory for storing an imaging signal imaged under illumination light of white light by the first illumination optical system;
A second memory for storing an imaging signal imaged under illumination light including light of the specific visible wavelength band by the second illumination optical system;
Picked-up image display means for displaying the picked-up image signals stored in the first memory and the second memory in different display areas;
An endoscopic apparatus comprising:

  According to this endoscope apparatus, the imaging signals are stored in different memories corresponding to the types of illumination light, and the imaging signals of each memory are displayed in different display areas. A lower observation image and an observation image under illumination light with light in a specific visible wavelength band can be displayed separately. Thereby, diagnosis can be performed while comparing a normal observation image with an image observed at a specific wavelength.

(9) The endoscope apparatus according to (8),
The endoscope apparatus characterized in that the illumination light control means alternately switches the illumination of the white light and the illumination including the light in the specific visible wavelength band for each imaging frame by the imaging element.

  According to this endoscope, by alternately capturing a captured image under illumination of white light and a captured image under illumination including light in a specific visible wavelength band, both images can be acquired substantially simultaneously. Two types of image information can be displayed simultaneously in real time.

(10) The endoscope apparatus according to any one of (7) to (9),
The image sensor includes a color filter for detecting a specific detection color component;
The half width of the peak of the emission spectrum curve of the specific visible wavelength band emitted by the light emitting element is narrower than the half width of the peak of the spectral sensitivity curve of the wavelength band of the color filter for detecting the specific detection color. Endoscopic device.

  According to this endoscope apparatus, the half-value width of the emission peak of a specific visible wavelength band emitted by the light-emitting element is made narrower than the half-value width of the detection wavelength band peak of the color filter, so that the light emitted from the light-emitting element can be used. Are detected within the peak of one wavelength band and do not affect the other wavelength bands. Therefore, there is no influence of color mixing or the like. In addition, it becomes easy to adjust the depth of light to a region intended for observation, information from the layer to be observed can be acquired with certainty, and the contrast of the captured image can be increased.

(11) Using the endoscope device according to any one of (7) to (10), a frame image configured by including a plurality of detection color screens each detecting light having a different specific wavelength band, An image processing method for an endoscopic device that irradiates light from a plurality of types of light sources in different conditions in synchronization with imaging timing of each frame image while imaging multiple times,
An observation image when the subject is illuminated with the first light source is a first frame image, an observation image when the subject is illuminated with the second light source is a second frame image, and the first frame image and the second frame Frame images are taken repeatedly,
The luminance information of the specific detection color screen of the first frame image and the luminance information of the specific detection screen of the second frame image are combined to analyze the observation image by the light of the specific wavelength component from the light source device. An image processing method for an endoscopic device, characterized in that the image processing is obtained automatically.

  According to the image processing method of the endoscope apparatus, an observation image by light of a desired wavelength component can be selectively extracted by combining information on each detection color screen of the first frame image and the second frame image. Can do. That is, an observation image with light of a specific wavelength component that cannot be obtained directly from a frame image obtained by one imaging can be analytically obtained by using frame images around the time axis.

(12) The image processing method for an endoscope apparatus according to (11),
The image processing method for an endoscope apparatus, wherein the observation image with light of the specific wavelength component includes at least an observation image with outgoing light having a narrow wavelength bandwidth.

  According to the image processing method of this endoscope apparatus, an observation image based on a light component in a narrow wavelength band is analytically obtained. For example, when observing a blood vessel or a gland duct structure, the light penetration depth is narrow. The image with higher contrast can be obtained.

(13) The image processing method for an endoscope apparatus according to (11),
An image processing method for an endoscope, wherein the observation image with light of the specific wavelength component includes at least an observation image with outgoing light having a wide wavelength bandwidth.

  According to the image processing method of the endoscope apparatus, an observation image using a light component having a wide wavelength bandwidth can be analytically obtained, and an image under white illumination with higher color rendering can be obtained.

(14) The image processing method for an endoscope apparatus according to any one of (11) to (13),
An image processing method for an endoscope apparatus, wherein a pseudo color image is generated by converting an observation image with light having a specific wavelength component into a specific color tone.

  According to the image processing method of the endoscope apparatus, it is possible to highlight the capillaries and gland duct structures on the tissue surface, facilitate confirmation of the observation target, and improve diagnosis accuracy.

  According to the endoscope apparatus of the present invention, the diameter of the endoscope insertion portion is reduced, and the white light and a specific narrow visible wavelength band are suppressed while suppressing the heat generation of the LED element disposed at the distal end of the endoscope insertion portion. Can be selectively irradiated with a simple structure and observed. Further, according to the image processing method of the endoscope apparatus, it is possible to perform spectroscopic diagnosis with higher accuracy based on the image information from the endoscope apparatus.

Hereinafter, preferred embodiments of a light source device, an endoscope device using the same, and an image processing method will be described in detail with reference to the drawings.
FIG. 1 shows a conceptual configuration diagram of the endoscope apparatus of the present embodiment.
The endoscope apparatus 100 according to the present embodiment mainly includes an endoscope 10, a light source device 20, an image processing device 30, and a monitor 40.
The endoscope 10 includes a main body operation unit 11 and an endoscope insertion unit 13 that is connected to the main body operation unit 11 and is inserted into a subject (body cavity). An imaging element 15 and an imaging lens 17 that are imaging optical systems are disposed at the distal end portion of the endoscope insertion portion 13, and an illumination optical member 19 of an illumination optical system is connected to the imaging optical system in the vicinity thereof. An optical fiber 21 is disposed. The optical fiber 21 is connected to a light source device 20, which will be described in detail later, and an imaging signal from the imaging element 15 is input to the image processing device 30.

  The image sensor 15 is an image sensor such as a CCD (charge coupled device) or a CMOS (Complementary Metal-Oxide Semiconductor), and the image signal is processed by the image signal processor 27 based on a command from the controller 29. The image is converted into the image and subjected to appropriate image processing. The control unit 29 projects the image data output from the imaging signal processing unit 27 on a monitor 40 that is a captured image display unit, or connects to a network such as a LAN (not shown) to distribute information including the image data. The control unit 29 is connected to a first memory 51 and a second memory 52 for storing imaging signals. The first memory 51 and the second memory 52 will be described later.

Next, a configuration example of the illumination optical system will be described.
FIG. 2 is a schematic cross-sectional configuration diagram of the illumination optical system at the distal end of the endoscope insertion portion of the endoscope apparatus shown in FIG.
The illumination optical system includes a white light illumination system 61 for emitting white light and a special color light illumination system 63 for emitting special color light such as green light and blue light. The white light illumination system 61 includes a blue laser light source (first light source) 33 having a central wavelength of 445 nm and a condensing lens 41 that condenses the laser light from the blue laser light source 33 in the excitation light source unit 65, and an endoscope. The illumination optical member 19 disposed at the distal end of the insertion portion 13 includes a wavelength conversion member 45 that converts laser light into visible light. The excitation light source unit 65 and the illumination optical member 19 are connected by an optical fiber 21.

The blue laser light source 33 emits blue laser light while controlling the amount of emitted light based on a command from the white light driving unit 67, and the emitted light irradiates the wavelength conversion member 45 of the endoscope insertion unit 13 through the optical fiber 21. Is done.
The wavelength conversion member 45 absorbs a part of the laser light from the blue laser light source 33 and emits a plurality of types of phosphors (for example, YAG phosphors, BAM (BaMgAl ₁₀ O ₃₇ ), etc.) that emit light in green to yellow. Including phosphors). Thereby, the laser light from the blue laser light source 33 and the green to yellow excitation light converted from the laser light are combined to generate white light.

  As the blue laser light source 33, a broad area type InGaN laser diode can be used. Further, the optical fiber 21 is inserted into an opening hole 13a formed in the distal end hard portion (metal block) of the endoscope insertion portion 13, and the optical axis is aligned with a fixing jig 75 inserted into the opening hole 13a. Fixed. The fixing jig 75 fixes the wavelength conversion member 45 to the light emission side of the optical fiber 21, and receives the light emitted from the optical fiber 21 and emits the light emitted by the wavelength conversion member 45 to the front of the optical path. At this time, the blue laser light that passes through the wavelength conversion member 45 without wavelength conversion is diffused by the phosphor in the wavelength conversion member 45, and the laser beam having high straightness is 60 ° to 70 ° with respect to the optical axis. It is emitted as diffused light having a diffusion angle.

On the other hand, the spotlight illumination system 63 uses an LED (Light Emitting Diode) element as a light source, and includes a blue light emitting LED element 71 and a green light emitting LED element 73 connected to the spotlight driving unit 69. Composed.
The blue light-emitting LED element 71 and the green light-emitting LED element 73 are disposed in the housing seats 13b and 13c that are formed in the hard tip portion and have side walls as reflection surfaces, and in the vicinity of the housing seats 13b and 13c, an electrode pad 77A , 77B are arranged and connected to the N-type electrode and the P-type electrode of each LED element by wire bonding. Further, the LED elements 71 and 73, the electrode pads 77A and 77B, and the gold wire are molded with a transparent resin, and the molded transparent resins 79A and 79B function as lenses. In addition, although it described as blue LED and green LED, since green LED has low luminous efficiency, for example, you may mix the fluorescent substance, dye, or pigment etc. which emit green in transparent resin using 405 nm purple LED. . Similarly, a 375 nm ultraviolet LED and a phosphor emitting blue-violet light may be mixed in the resin and sealed.

The spot color light driving unit 69 controls the blue light emitting LED element 71 and the green light emitting LED 73 individually, and is controlled by the control unit 29 (FIG. 1) together with the white light driving unit 67. The white light driving unit 67, the spot color light driving unit 69, and the control unit 29 function as illumination light control means for switching illumination light.
With the above configuration, the blue laser light emitted from the optical fiber 21 from the blue laser light source 33 is irradiated to the wavelength conversion member 45, and the wavelength conversion member 45 absorbs a part of the blue laser light, and the blue laser light. Longer than that of light (green to yellow light).

  FIG. 3 is a graph showing the spectral distribution of light after the blue laser light has been wavelength-converted by the wavelength conversion member 45. The blue laser light from the blue laser light source 33 is represented by a bright line having a central wavelength of 445 nm, and the light emission intensity is increased in a wavelength band of approximately 450 nm to 700 nm by light emitted from the wavelength conversion member 45 by this laser light. White light is formed by the light of this wavelength band and the blue laser light.

  FIG. 4 shows emission spectra of the blue light-emitting LED element 71 and the green light-emitting LED element 73 of the spot color light illumination system 63. The emission spectrum by the blue light emitting LED element 71 is light in a narrow wavelength band with a half width of about 450 to 480 nm, and the emission spectrum by the green light emitting LED element 73 is light in a narrow wavelength band of about 520 to 560 nm at a half width. is there.

  The blue, green, and other wavelengths of light emitted from the wavelength conversion member 45 are emitted at the same time, but when detecting the observation light of the illumination light by each light component, For example, by detecting only the green light component with the image sensor 15, the green light component and other light components can be easily separated. Also, the blue light component can be similarly separated. Therefore, the problem of color mixing does not occur in the subsequent signal processing.

Next, a usage example of the endoscope apparatus 100 in which the light source device 20 having the above-described configuration is incorporated in the endoscope 10 will be described.
As shown in FIG. 1, in the endoscope apparatus 100, the endoscope insertion portion 13 is inserted into a body cavity, and white illumination light is emitted from the distal end of the endoscope insertion portion 13 through the illumination optical member 19. Further, the illumination light of the special color light is emitted from the LED elements 71 and 73. The white light and the special color light are switched, and only one of them is emitted. Then, the reflected light applied to the subject with the emitted light is imaged by the imaging element 15 through the imaging lens 17. The imaging signal obtained by imaging is subjected to appropriate image processing by the imaging signal processing unit 27 and output to the monitor 40. Alternatively, it is stored in a recording medium.

  At the time of imaging using such an imaging device 15, at the time of a normal endoscope diagnosis in which irradiation is performed with white illumination light in a body cavity, the control unit 29 uses a white light driving unit 67 shown in FIG. The output of the laser light from the blue laser light source 33 is turned on, and the outputs of the blue light emitting LED element 71 and the green light emitting LED element 73 are turned off by the special color light driving unit 69. In this case, the subject is irradiated with white illumination light generated by the laser light from the blue laser light source 33 and the excitation light emitted from the wavelength conversion member 45. When performing spectroscopic diagnosis by the endoscope apparatus 100, the control unit 29 turns on the outputs of the blue light emitting LED element 71 and the green light emitting LED element 73 by the spot color light driving unit 69 and the white light driving unit 67. The output of the blue laser light source 33 is turned off. In this case, the subject is irradiated with blue light and green light in a narrow wavelength band by the blue light emitting LED element 71 and the green light emitting LED element 73. Then, the reflected light from the subject irradiated with the green light and the blue light simultaneously is imaged by the imaging element 15, and the imaging signal processing unit 27 generates a pseudo color image for spectral diagnosis. For example, the pseudo color image is generated by converting the green detection signal (the reflected light component of the narrow-band green light) from the image sensor 15 into a red color tone and the blue detection signal into a blue and green color tone. According to this pseudo color image, the surface fine structure (capillary blood vessel, mucous membrane fine structure, etc.) of the surface layer of the subject can be clearly observed.

Here, a specific control example when performing spectral diagnosis will be described.
FIG. 5 is an explanatory diagram conceptually showing a plurality of frame images (a) obtained in time series by imaging with an imaging optical system and a state (b) in which these frame images are rearranged and displayed. Here, control is performed to separately display an observation image under illumination light with white light and an observation image under illumination light with light in a specific visible wavelength band (green, blue) on the monitor 40, respectively.
As shown in FIG. 5A, the control unit 29 controls the emitted light from the light source device 20 to emit blue laser light having a central wavelength of 445 nm and irradiate the subject with white light in the first frame. To do. The imaging element 15 images a subject illuminated with white light, and stores the imaging signal in the first memory 51 (see FIG. 1).

  Next, the control unit 29 controls the emitted light from the light source device 20, and in the second frame, the subject emits green light and blue light in a narrow wavelength band by the blue light emitting LED element 71 and the green light emitting LED element 73, respectively. Irradiate. The imaging element 15 images the subject illuminated with green light and blue light, and stores the imaging signal in the second memory 53.

  Thereafter, similarly, the third frame (odd frame) repeats the processing of illumination / imaging / image signal storage in the same manner as the first frame in the third frame (odd frame) and the second frame in the fourth frame (even frame). . That is, the illumination of white light and the illumination including light in a specific visible wavelength band are alternately switched for each imaging frame of the imaging device 15. Then, as shown in FIG. 5B, the illumination image by the white light is accumulated in the first memory 51, and the narrowband diagnostic image by the green light and the blue light is accumulated in the second memory 53. . As shown in FIG. 6, the image information stored in the first memory 51 and the second memory 53 is displayed in different display areas 55 and 57 on the monitor 40 as shown in FIG. To do. The size of each display area is the same in the illustrated example, but it can be set arbitrarily, such as displaying either one larger than the other or displaying the other image smaller in either image display area. Can do.

  Thus, by alternately capturing a captured image under illumination of white light and a captured image under illumination including light in a specific visible wavelength band, both images can be acquired substantially simultaneously. The image information can be displayed simultaneously in real time. Further, by displaying the captured images side by side, the observation position and the properties of the part can be grasped at the same time, and the diagnostic accuracy by the spectroscopic diagnosis can be further enhanced.

In addition to the combination of blue light emitted by a blue light emitting LED element and green light emitted by a green light emitting LED element as described above, when imaging is performed by irradiating light in a specific visible wavelength band and performing spectroscopic diagnosis, Various combinations of light components are possible.
For example, instead of the blue light emitted from the blue light emitting LED element 71, a pseudo color image can be generated by using the blue laser light emitted from the blue laser light source 33 for white illumination as the narrow band spot color light. The pseudo color image thus obtained may be an image useful for spectroscopic diagnosis because the wavelength band of the emitted light is narrower for the laser than the LED element.

In order to perform such a combination of light components, an image calculation process across frame images with different imaging timings is performed on a plurality of frame images captured in time series by imaging with an imaging optical system.
That is, as described with reference to FIG. 5, a frame image having a plurality of detection color screens (screens of three primary colors of blue, green, and red) that detect different specific wavelength band lights is displayed a plurality of times. On the other hand, light from a plurality of types of light sources is irradiated under different conditions in synchronization with the imaging timing of each frame image. When the observation image when the subject is illuminated with the first light source is the first frame image, and the observation image when the subject is illuminated with the second light source is the second frame image, the first frame image and the second frame image And the luminance information of the specific detection color screen of the first frame image and the luminance information of the specific detection screen of the second frame image are combined to analyze the observation image by the light of the specific wavelength component. Ask for.

FIG. 7 shows main light components included in the screen of a specific detection color for each frame image captured in the same manner as in FIG. Here, an example in which the phosphor of the wavelength conversion member 45 is a YAG phosphor will be described.
The first frame, which is an imaging signal obtained by irradiating with blue laser light having a central wavelength of 445 nm, is illuminated by blue laser light having a central wavelength of 445 nm from the blue laser light source 33 on the blue detection light screen B1. In the green detection light screen G1, the observation light under the illumination light by the green light fluorescence by the YAG phosphor of the wavelength conversion member 45 is included in the green detection light screen G1, and in the red detection light screen R1, the wavelength conversion member Observation light under illumination light by red fluorescence by 45 YAG phosphors is included.

  Further, the second frame, which is an imaging signal obtained by causing the blue light emitting LED element 71 and the green light emitting LED element 73 to emit light next, is under illumination light by the blue light emitting LED element 71 in the blue detection light screen B2. In the green detection light screen G2, the observation light under the illumination light by the green light emitting LED element 73 is included.

  Here, considering an observation image using white light, the white light used for illumination has a color tone different from the actual appearance when the wavelength component in a specific narrow range becomes strong. Therefore, ideally, it is desirable to illuminate with light having a spectrum with a relatively flat visible wavelength band. However, since the white illumination according to the present configuration uses the blue laser light as a bright line for white illumination, the spectrum of the illumination light can be flattened by replacing it with the light emitted by the blue light emitting LED 71 having a wider wavelength width than the laser light. . That is, in white illumination, color rendering can be improved by using blue light having a relatively wide wavelength bandwidth by the LED elements in the second frame, rather than illumination light in which laser light that is a bright line component is mixed. Therefore, as an observation light image by white light, without using the first frame as it is, by combining G1, R1 of the first frame and B2 of the second frame, an observation light image by white light with better color rendering can be obtained. Obtainable.

  Further, as the observation light image by the narrow band illumination light, the observation light by the blue laser light obtained in B1 and the observation light by the narrow band light by the light emission of the green light emitting LED element 73 obtained by G2 are combined, and this is used for enhancement processing. It can be used as an image. In this case, since the wavelength width of the blue light is narrowed, the tissue surface layer portion to be observed can be limited to a shallower region on the surface side.

  As described above, it is possible to easily provide image information convenient for diagnosis by using each detection light screen of each frame obtained by imaging in an appropriate combination. In addition, it is possible to easily obtain an image in which the blue light that is difficult to reach the deep part of the mucosa clearly shows the capillaries in the surface layer of the tissue, and the green light that reaches the inside of the tissue clearly shows the deep blood vessels. it can.

  Further, the configuration may be such that the white illumination light and the light with a specific narrow visible wavelength band can be switched by a simple hand operation by a switch 12 or the like provided in the main body operation unit 11 of the endoscope 10. In this case, the illumination light can be manually switched at an arbitrary timing, and usability can be improved.

As described above, according to the endoscope apparatus 100 of the present embodiment, by using laser light as the white light source of the illumination optical system, light can be guided by the optical fiber, and high-intensity light is suppressed from being diffused and highly efficient. Can be propagated. Further, since the white light guide path can be formed of an optical fiber, it is easy to reduce the diameter of the endoscope insertion portion without requiring a conventional light guide (optical fiber bundle). That is, in order to guide light necessary for the light guide to the distal end of the endoscope insertion portion 13, the diameter of the light guide is required to be at least about 1 mm or more. However, in the configuration of this embodiment using a single optical fiber, the outer skin is used. The outer diameter including the protective material can be as small as about 0.3 mm. In addition, since the LED element illuminates by directly converting energy into a necessary wavelength band, light with high efficiency and high illuminance can be obtained, and light in a narrow wavelength band is obtained by a xenon lamp generally used in endoscopes. Compared to the case of filtering out, it is possible to realize the same brightness with about 1/20 of the power consumption. Furthermore, since exhaust heat can be reduced, the cooling fan and the like can be reduced in size and noise.
Since phosphor excitation light is used as illumination light, there is no noise superposition due to speckle (interference), which is likely to occur when laser light is used directly as illumination light, and flickering in moving images does not occur.

  Further, according to the configuration of the endoscope apparatus 100 of the present embodiment, the heat capacity is reduced as the diameter of the endoscope insertion portion 13 is reduced, and heat from the LED elements 71 and 73 is feared. White illumination light that requires a large amount of light is supplied using laser light, and special color illumination light required for spectroscopic diagnosis is supplied using LED elements 71 and 73. Therefore, the LED element is always lit at high output. Compared with the case where it does, calorific value can be suppressed.

  In addition, light emitted from the LED elements 71 and 73 is collected by a lens formed of the transparent resins 79A and 79B, and is emitted toward a desired irradiation position. Therefore, as shown in FIG. 8 showing the relationship between the observation region and the spot color light irradiation region, the entire region of the observation region 81 by the image sensor 15 is not illuminated by the LED elements 71 and 73, and a part of the observation region 81 is spot light. It can be an illumination area 83. By selectively irradiating the spot light illumination area 83 to a narrow area, the amount of light emitted from the LED elements 71 and 73 can be reduced, and the amount of heat generated can be suppressed.

Next, a modification of the endoscope apparatus 100 having the above configuration will be described.
<Modification 1>
FIG. 9 shows another cross-sectional configuration diagram of the endoscope insertion portion.
The housing seats for the LED elements 71 and 73 formed in the endoscope insertion portion 13 of the endoscope apparatus 100 described above are provided with the LED elements 71 and 73, respectively. It can also be arranged in the storage seat 13d. In this case, the plurality of LED elements 71, 73 can be molded together with the transparent resin 79C, the manufacturing process is simplified, and each LED element 71, 73 shares one condensing lens. Irradiation unevenness of the light is suppressed.

<Modification 2>
FIG. 10 shows a configuration diagram of another optical system of the light source device.
The LED elements in this case are blue light emitting LED elements 71 and 73 (one of which is arranged in parallel in the direction perpendicular to the paper surface) and an infrared (780 nm) light emitting LED element 76. These LED elements 71, 73, 74 are arranged in the same accommodation seat 13e and molded with a transparent resin 79D. The blue light-emitting LED element 71, the green light-emitting LED element 73, and the infrared light-emitting LED element 74 are all connected to the spot color light driving unit 69, and their light emission states are controlled.

  FIG. 11 shows emission spectra of the blue light emitting LED element 71, the green light emitting LED element 73, and the infrared light emitting LED element 74 in this case. According to this configuration, since infrared light can be emitted in addition to blue light to green light used for spectroscopic diagnosis, for example, diagnosis by infrared light observation is possible. Infrared light observation means deep blood vessels and thickening in the deep mucosa that are difficult to see by the human eye by irradiating with infrared light after intravenous injection of ICG (Indocyanine Green), which easily absorbs infrared light. Is a technology for highlighting. Blood flow information can also be displayed.

In each of the endoscope apparatuses described above, light in a narrow wavelength band used for spectroscopic diagnosis or the like, that is, light emitted from the blue light emitting LED element 71, the green light emitting LED element 73, etc., has a half band width of 40 nm or less. It is preferably set. This is due to the following reason.
An image sensor such as a CCD or CMOS has a color filter, for example, R (red), G (green), and B (blue) primary colors (in addition, there are combinations such as cyan, magenta, and yellow as complementary colors). ) Is generated as the specific detection color. The light intensity detection of each detection color detects the light intensity within a sensitive wavelength band of a certain wavelength width, but in reality the wavelengths of each detection color are close to each other, and some of the sensitive wavelength bands are mutually It overlaps. However, when there are many overlapping areas, color mixing occurs, and thus the overlapping areas are usually narrowed.

  The sensitive wavelength band is designed to be, for example, 100 nm or less for B, 80 nm or less for G, and 100 nm or less for R to prevent color mixing with G (in this specification, this is called a substantially sensitive wavelength band). To do). Therefore, in order to detect each detected color without the influence of color mixing in the image sensor, the wavelength band of light emission of the LED element may be set to a wavelength width narrower than this substantially sensitive wavelength band. In other words, the wavelength at which the half width of the peak of the emission spectrum curve in the specific visible wavelength band emitted by the LED element detects the specific detection color component (detection color for detecting the emission color of the LED element) of the color filter. The wavelength width is narrower than the half width of the peak of the spectral sensitivity curve in the band. Thereby, the emitted light in a specific wavelength band is not detected across a plurality of sensitive wavelength bands. In some cases, the center of the spectrum is shifted from the center of the color filter in accordance with the subject to be observed. In this case, it is necessary to narrow the width of the wavelength band of the emitted light.

  For this reason, the width of the wavelength band of the emitted light of each LED element 71, 73 is set to 60 nm or less, preferably 40 nm or less, and more preferably 20 nm or less. Moreover, it is preferable that it is 10 nm or more from a viewpoint of light intensity.

  In addition to the reason for the detection of the light intensity of the image sensor, the reason for narrowing the band is that it is necessary to narrow the band when performing diagnosis with a narrow band imaging (NBI). It is done. When illumination light is irradiated onto a living tissue, the light propagates diffusely. When the absorption and scattering characteristics are strong, the light is observed as reflected light without being propagated deep inside the living tissue. The absorption / scattering characteristics have a strong wavelength dependence, and the shorter the wavelength, the stronger the scattering characteristics, and the penetration depth of light into the living tissue is determined by the wavelength of the irradiated light. In particular, for observation of the fine structure of the mucosal surface, which is important for the diagnosis of early lesions, information from within the shallow layer from the surface is important. In this case, the wavelength band of the emitted light of the LED element is desired. It is possible to selectively extract information from the observation target layer by narrowing the band with the wavelength of.

As described above, according to the endoscope apparatus of each embodiment, the diameter of the white light formed including the laser light and the excitation light emitted from the phosphor and the light of a specific narrow visible wavelength band is reduced. However, it can selectively irradiate with a simple configuration.
Note that the light source device and the endoscope device using the light source device are not limited to the above-described embodiments, and can be appropriately modified and improved.

It is a notional block diagram of the endoscope apparatus of the present invention. FIG. 2 is a schematic cross-sectional configuration diagram of an illumination optical system at a distal end of an endoscope insertion portion of the endoscope apparatus illustrated in FIG. 1. It is a graph which shows the spectrum distribution of the light after blue laser light is wavelength-converted by the wavelength conversion member. It is the emission spectrum of the blue light emitting LED element of a special color illumination system, and a green light emitting LED element. It is explanatory drawing which shows notionally the several frame image (a) imaged by the imaging optical system and obtained in time series, and a mode (b) which arranges and displays these frame images. It is explanatory drawing which shows typically a mode that the imaging signal preserve | saved at the 1st memory and the 2nd memory was each displayed on the different display area on a monitor. It is explanatory drawing which shows the main light components contained in the screen of a specific detection color with respect to each frame image imaged similarly to FIG. It is explanatory drawing which shows the relationship between an observation area | region and a spot color light irradiation area | region. It is a block diagram which shows the other cross section of an endoscope insertion part. It is a block diagram which shows the other optical system of a light source device. It is an emission spectrum of a blue light emitting LED element, a green light emitting LED element, and an infrared light emitting LED element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Endoscope 11 Main body operation part 13 Insertion part 15 Image pick-up element 19 Optical member for illumination 20 Light source device 21 Optical fiber 27 Imaging signal processing part 29 Control part 30 Image processing apparatus 33 Blue laser light source 45 Wavelength conversion member 51 1st memory 53 Second memory 55, 57 Display area 61 White light illumination system 63 Special color light illumination system 65 Excitation light source unit 67 White light drive unit 69 Special color light drive unit 71 Blue light emitting LED element 73 Green light emitting LED element 74 Infrared light emitting LED element 79A 79B Transparent resin 81 Observation area 83 Spot light irradiation area 100 Endoscope device

Claims (14)

A first light source that emits laser light; an optical fiber that is incident on the light incident side to transmit the laser light to the distal end of the endoscope insertion portion; and is disposed at the light emitting side of the optical fiber and emits excitation light by the laser light. A wavelength conversion member including one type of fluorescent material, and mixing the laser light and excitation light emitted from the wavelength conversion member to emit white light from the distal end of the endoscope insertion portion Illumination optics,
A second illumination optical system provided with a light emitting element disposed at the distal end of the endoscope insertion portion and emitting light in a specific visible wavelength band;
An endoscope apparatus comprising: The endoscope apparatus according to claim 1,
An endoscope apparatus in which the light emitting element of the second illumination optical system is an LED element. The endoscope apparatus according to claim 1 or 2,
An endoscope apparatus in which the second illumination optical system includes a plurality of light emitting elements that emit light at different center wavelengths. The endoscope apparatus according to any one of claims 1 to 3,
An endoscope apparatus in which the second illumination optical system includes a light emitting element that emits at least green light. The endoscope apparatus according to any one of claims 1 to 4,
An endoscope apparatus in which the second illumination optical system includes a light emitting element that emits at least blue light. The endoscope apparatus according to any one of claims 1 to 5,
An endoscope apparatus in which the second illumination optical system includes a light emitting element that emits at least red light or infrared light. The endoscope apparatus according to any one of claims 1 to 6,
An imaging means including an imaging element that receives light from a site to be observed through an observation window provided at a distal end of the endoscope insertion unit and outputs an imaging signal;
Illumination light control means for switching and illuminating white light by the first illumination optical system and light of a specific visible wavelength band by the second illumination optical system;
An endoscopic apparatus comprising: The endoscope apparatus according to claim 7,
A first memory for storing an imaging signal imaged under illumination light of white light by the first illumination optical system;
A second memory for storing an imaging signal imaged under illumination light including light of the specific visible wavelength band by the second illumination optical system;
Picked-up image display means for displaying the picked-up image signals stored in the first memory and the second memory in different display areas;
An endoscopic apparatus comprising: The endoscope apparatus according to claim 8, wherein
The endoscope apparatus characterized in that the illumination light control means alternately switches the illumination of the white light and the illumination including the light in the specific visible wavelength band for each imaging frame by the imaging element. The endoscope apparatus according to any one of claims 7 to 9,
The image sensor includes a color filter for detecting a specific detection color component;
The half width of the peak of the emission spectrum curve of the specific visible wavelength band emitted by the light emitting element is narrower than the half width of the peak of the spectral sensitivity curve of the wavelength band of the color filter for detecting the specific detection color. Endoscopic device. Using the endoscope apparatus according to any one of claims 7 to 10, a frame image having a plurality of detection color screens each detecting a different specific wavelength band light is provided a plurality of times. An image processing method for an endoscope apparatus that irradiates light from a plurality of types of light sources under different conditions in synchronization with imaging timing of each frame image,
An observation image when the subject is illuminated with the first light source is a first frame image, an observation image when the subject is illuminated with the second light source is a second frame image, and the first frame image and the second frame Frame images are taken repeatedly,
The luminance information of the specific detection color screen of the first frame image and the luminance information of the specific detection screen of the second frame image are combined to analyze the observation image by the light of the specific wavelength component from the light source device. An image processing method for an endoscopic device, characterized in that the image processing is obtained automatically. An image processing method for an endoscope apparatus according to claim 11,
The image processing method for an endoscope apparatus, wherein the observation image with light of the specific wavelength component includes at least an observation image with outgoing light having a narrow wavelength bandwidth. An image processing method for an endoscope apparatus according to claim 11,
An image processing method for an endoscope, wherein the observation image with light of the specific wavelength component includes at least an observation image with outgoing light having a wide wavelength bandwidth. An image processing method for an endoscope apparatus according to any one of claims 11 to 13,
An image processing method for an endoscope apparatus, wherein a pseudo color image is generated by converting an observation image with light having a specific wavelength component into a specific color tone.

Images