WO2017142096A1 - Endoscope light source device and endoscope system - Google Patents

Endoscope light source device and endoscope system Download PDF

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Publication number
WO2017142096A1
WO2017142096A1 PCT/JP2017/006123 JP2017006123W WO2017142096A1 WO 2017142096 A1 WO2017142096 A1 WO 2017142096A1 JP 2017006123 W JP2017006123 W JP 2017006123W WO 2017142096 A1 WO2017142096 A1 WO 2017142096A1
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Prior art keywords
light
light source
phosphor
wavelength
emitted
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PCT/JP2017/006123
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French (fr)
Japanese (ja)
Inventor
邦彦 尾登
文香 横内
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Hoya株式会社
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Priority to CN201790000597.7U priority Critical patent/CN209091323U/en
Priority to JP2018500243A priority patent/JP6695416B2/en
Publication of WO2017142096A1 publication Critical patent/WO2017142096A1/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
    • A61B1/06—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor with illuminating arrangements
    • A61B1/0655—Control therefor

Definitions

  • the present invention relates to an endoscope light source device and an endoscope system for irradiating a subject with light.
  • Patent Document 1 An endoscope system that can change the spectral intensity characteristics of irradiated light and take a special image is known.
  • Patent Document 1 a pamphlet of International Publication No. 2012/108420 (hereinafter referred to as “Patent Document 1”) describes a specific configuration of a light source device used in this type of endoscope system.
  • the endoscope system described in Patent Document 1 includes a light source device on which two light emitting diodes (LEDs) are mounted and an optical filter.
  • One of the two LEDs is a purple LED that emits light in a purple wavelength band.
  • the other LED is a phosphor LED having a blue LED and a yellow phosphor, and emits pseudo white light by mixing blue LED light and yellow fluorescence.
  • the optical filter is a wavelength selection filter that passes only light in a wavelength band having high absorbance with respect to a specific living tissue, and can be inserted into and extracted from the optical path of light emitted from the phosphor LED.
  • the light source device described in Patent Document 1 when the optical filter is removed from the optical path, the light emitted from the phosphor LED is irradiated to the subject as white light without limiting the wavelength band. .
  • the optical filter when the optical filter is inserted on the optical path, the subject is irradiated with both the irradiation light emitted from the phosphor LED and the wavelength band limited and the irradiation light emitted from the purple LED.
  • the spectral intensity characteristic of the irradiation light and irradiating the subject with only light in a specific wavelength band, it is possible to obtain a captured image in which a specific tissue is emphasized among subjects in the living body.
  • the wavelength band of irradiation light emitted from the white LED is limited by an optical filter, and an unnecessary wavelength band is obtained.
  • the light is cut. Since the cut light is not irradiated to the subject, there is a problem that the light use efficiency of the light source device is low.
  • the present invention has been made in view of the above circumstances, and an object of the present invention is for an endoscope capable of irradiating irradiation light having high intensity only in a specific wavelength band with high light utilization efficiency.
  • a light source device and an endoscope system are provided.
  • An endoscope light source device is excited by a first solid-state light emitting element that emits light of a first wavelength band and light of a first wavelength band, and emits first fluorescence.
  • a first light source unit having a first phosphor that emits, and a phosphor insertion / extraction means that supports the first phosphor so as to be insertable / removable with respect to an optical path of light emitted from the first solid-state light emitting element, Is provided.
  • the first phosphor is inserted into the optical path of the light emitted from the first solid state light emitting device by the phosphor inserting / extracting means, the first wavelength band of light and the first wavelength band are transmitted from the first light source unit.
  • the first phosphor is removed from the optical path of the light emitted from the first solid state light emitting device by the phosphor insertion / extraction means, the light of the first wavelength band is emitted from the first light source unit. Supplied to the endoscope.
  • the subject can be irradiated with normal light having a wide wavelength band in the visible light region by inserting the phosphor into the optical path of the light emitted from the solid state light emitting device. Further, by removing the phosphor from the optical path, it is possible to irradiate the subject with special light whose intensity of light in a wavelength band having high absorbance with respect to a specific biological tissue of the subject is higher than in other wavelength bands.
  • an optical filter such as a wavelength limiting filter when switching the spectral intensity characteristics of the irradiation light, it is possible to suppress light amount loss due to switching of the spectral intensity characteristics.
  • the endoscope light source device includes, for example, a second light source unit that emits light in a wavelength band having a peak wavelength different from the peak wavelength of the first fluorescence wavelength band; First optical path synthesis means for synthesizing the optical path of the light emitted from the first light source unit and the optical path of the light emitted from the second light source unit, and supplying the combined light to the endoscope Are further provided.
  • the second light source unit is excited by the second solid light emitting element and the light emitted from the second solid light emitting element, and emits second fluorescence. And a phosphor.
  • the peak wavelength of the second fluorescence wavelength band is different from the peak wavelength of the first wavelength band and the peak wavelength of the first fluorescence wavelength band.
  • the endoscope light source device is different from the peak wavelength of light emitted from the first light source unit and the peak wavelength of light emitted from the second light source unit, for example.
  • a third light source unit that emits light in a third wavelength band having a peak wavelength, an optical path of light synthesized by the first optical path synthesis unit, and an optical path of light emitted from the third light source unit
  • a second optical path synthesizing unit that synthesizes and supplies the combined optical path to the endoscope.
  • the first light source unit is excited by, for example, light in the first wavelength band emitted from the first solid state light emitting device, and is different from the peak wavelength of the first fluorescence.
  • a third phosphor that emits third fluorescence having a peak wavelength is further included.
  • the first phosphor is inserted into the optical path of the light emitted from the first solid-state light emitting element by the phosphor insertion / extraction means, the light in the first wavelength band from the first light source unit, the first Fluorescence and third fluorescence are emitted along the same optical path and supplied to the endoscope.
  • the first wavelength band and the third fluorescence are the same from the first light source unit. And are supplied to the endoscope.
  • the first light source unit is excited by, for example, light in the first wavelength band emitted from the first solid-state light emitting element, and the first fluorescence peak wavelength and the third wavelength.
  • a fourth phosphor that emits a fourth fluorescence having a peak wavelength different from the peak wavelength of the fluorescence.
  • the phosphor insertion / extraction means supports the first phosphor and the fourth phosphor so that they can be individually inserted into and removed from the optical path of the light emitted from the first solid state light emitting device.
  • the endoscope light source device may further include a turret that rotates in synchronization with a predetermined imaging cycle.
  • phosphors having different light emission characteristics are arranged in the circumferential direction on the turret.
  • an endoscope system includes the above-described endoscope light source device and an endoscope.
  • an endoscope light source device and an endoscope system capable of irradiating irradiation light having high intensity only in a specific wavelength band with high light utilization efficiency are provided.
  • FIG. 1 is a block diagram illustrating a configuration of an electronic endoscope system according to a first embodiment of the present invention. It is a block diagram of the light source device for endoscopes concerning a 1st embodiment of the present invention. It is a block diagram of the light source device for endoscopes concerning a 1st embodiment of the present invention. It is a figure which shows the spectral intensity distribution of the irradiation light inject
  • FIG. 1 is a block diagram showing a configuration of an electronic endoscope system 1 including an endoscope light source device 201 according to the first embodiment of the present invention.
  • the electronic endoscope system 1 is a system specialized for medical use, and includes an electronic scope 100, a processor 200, and a monitor 300.
  • the processor 200 includes a system controller 21 and a timing controller 22.
  • the system controller 21 executes various programs stored in the memory 23 and controls the entire electronic endoscope system 1 in an integrated manner.
  • the system controller 21 is connected to the operation panel 24.
  • the system controller 21 changes each operation of the electronic endoscope system 1 and parameters for each operation in accordance with an instruction from the operator input to the operation panel 24.
  • the input instruction by the operator includes, for example, an instruction to switch the observation mode of the electronic endoscope system 1.
  • the observation mode includes a normal observation mode and a special observation mode. Details of each observation mode will be described later.
  • the timing controller 22 outputs a clock pulse for adjusting the operation timing of each unit to each circuit in the electronic endoscope system 1.
  • the processor 200 includes a light source device 201.
  • FIG. 2 is a block diagram of the light source device 201 according to the first embodiment of the present invention.
  • the light source device 201 includes a first light source unit 111 and a second light source unit 112.
  • the first and second light source units 111 and 112 are individually controlled to emit light by the first and second light source drive circuits 141 and 142, respectively.
  • the light source device 201 is provided in the processor 200.
  • the light source device 201 is separate from the processor 200 (more precisely, a part constituting the image processing device). It may be a device.
  • the first light source unit 111 includes a purple light emitting diode (LED: Light Emitting Diode) 111a that emits light in a purple wavelength band (for example, a wavelength of 395 to 435 nm) and a blue phosphor 111b.
  • the blue phosphor 111b is excited by the purple LED light emitted from the purple LED 111a and emits fluorescence in a blue wavelength band (for example, a wavelength of 430 to 550 nm).
  • the blue phosphor 111b is supported by the phosphor insertion / extraction mechanism 151 so that it can be inserted into and removed from the optical path. Specifically, the blue phosphor 111b is inserted into or removed from the optical path of the purple LED light emitted from the purple LED 111a according to the observation mode. As shown by a solid line in FIG. 2, when the blue phosphor 111b is inserted on the optical path of the purple LED light, the blue phosphor 111b emits blue fluorescence. Thereby, both the purple LED light and the blue fluorescence are emitted from the light source unit 111. Further, as shown by the dotted line in FIG. 2, when the blue phosphor 111b is removed from the optical path of the purple LED light, the blue phosphor 111b is not excited and does not emit fluorescence. Therefore, only the purple LED light is emitted from the light source unit 111.
  • the second light source unit 112 includes a blue LED 112a that emits light in a blue wavelength band (for example, a wavelength of 420 to 480 nm), and a yellow phosphor 112b.
  • the yellow phosphor 112b is excited by the blue LED light emitted from the blue LED 112a, and emits fluorescence in a yellow wavelength band (for example, a wavelength is 420 to 700 nm).
  • the yellow phosphor 112b is attached on the light emitting surface of the blue LED 112a, and unlike the blue phosphor 111b, it cannot be inserted into and removed from the optical path of the blue LED light.
  • Collimating lenses 121 and 122 are arranged in front of the light source units 111 and 112 in the light emission direction, respectively.
  • the light emitted from the first light source unit 111 is converted into parallel light by the collimator lens 121 and is incident on the dichroic mirror 131.
  • the light emitted from the second light source unit 112 is converted into parallel light by the collimator lens 122 and is incident on the dichroic mirror 131.
  • the dichroic mirror 131 combines the optical path of the light emitted from the first light source unit 111 and the optical path of the light emitted from the second light source unit 112.
  • the dichroic mirror 131 has a cutoff wavelength in the vicinity of a wavelength of 520 nm, transmits light having a wavelength shorter than the cutoff wavelength, and reflects light having a wavelength longer than the cutoff wavelength. Yes. Therefore, the purple LED light and the blue fluorescence emitted from the first light source unit 111 are transmitted through the dichroic mirror 131. Further, the yellow fluorescence emitted from the second light source unit 112 is reflected by the dichroic mirror 131. Thereby, the optical path of the light emitted from the first light source unit 111 and the light emitted from the second light source unit 112 is combined. The light whose optical path is synthesized by the dichroic mirror 131 is emitted from the light source device 201 as the irradiation light L.
  • FIG. 3 is a block diagram conceptually showing only the light source units 111 and 112 and the dichroic mirror 131 in the light source device 201. Since the blue phosphor 111b is separate from the purple LED 111a, the blue phosphor 111b and the purple LED 111a are shown in separate blocks in FIG. On the other hand, since the yellow phosphor 112b is attached to the light emitting surface of the blue LED 112a and is integrally formed with the blue LED 112a, the yellow phosphor 112b and the blue LED 112a are shown as one block in FIG. Yes.
  • the dichroic mirror 131 synthesizes optical paths of light having different wavelengths. Therefore, in FIG. 3, the dichroic mirror 131 is indicated by an addition symbol “+”. In FIG. 3, the collimating lenses 121 and 122 arranged in front of the light source units 111 and 112 are omitted.
  • each arrow indicates an optical path of light.
  • the purple LED light emitted from the purple LED 111a of the first light source unit 111 and the blue fluorescence emitted from the blue phosphor 111b are emitted in the same optical path.
  • the blue LED light emitted from the blue LED of the second light source unit 112 and the yellow fluorescence emitted from the yellow phosphor are emitted in the same optical path.
  • the optical path of the light emitted from the first light source unit and the optical path of the light emitted from the second light source unit are combined by the dichroic mirror 131.
  • the light whose optical path is synthesized by the dichroic mirror 131 is emitted as the irradiation light L from the light source device 201.
  • the irradiation light L emitted from the light source device 201 is condensed on the incident end face of the LCB (Light Carrying Bundle) 11 by the condenser lens 25 and enters the LCB 11.
  • LCB Light Carrying Bundle
  • the irradiation light L incident on the LCB 11 propagates in the LCB 11.
  • the irradiation light L propagating through the LCB 11 is emitted from the emission end surface of the LCB 11 disposed at the tip of the electronic scope 100 and is irradiated onto the subject via the light distribution lens 12.
  • the return light from the subject irradiated with the irradiation light L from the light distribution lens 12 forms an optical image on the light receiving surface of the solid-state imaging device 14 via the objective lens 13.
  • the solid-state imaging device 14 is a single-plate color CCD (Charge Coupled Device) image sensor having a Bayer pixel arrangement.
  • the solid-state imaging device 14 accumulates an optical image formed by each pixel on the light receiving surface as a charge corresponding to the amount of light, and generates R (Red), G (Green), and B (Blue) image signals. Output.
  • the solid-state imaging device 14 is not limited to a CCD image sensor, and may be replaced with a CMOS (Complementary Metal Oxide Semiconductor) image sensor or other types of imaging devices.
  • the solid-state image sensor 14 may also be one having a complementary color filter mounted thereon.
  • a driver signal processing circuit 15 is provided in the connection part of the electronic scope 100.
  • An image signal of a subject irradiated with light from the light distribution lens 12 is input to the driver signal processing circuit 15 from the solid-state imaging device 14 at a frame period.
  • the frame period is, for example, 1/30 seconds.
  • the driver signal processing circuit 15 performs a predetermined process on the image signal input from the solid-state imaging device 14 and outputs the processed image signal to the upstream signal processing circuit 26 of the processor 200.
  • the driver signal processing circuit 15 also accesses the memory 16 and reads the unique information of the electronic scope 100.
  • the unique information of the electronic scope 100 recorded in the memory 16 includes, for example, the number and sensitivity of the solid-state imaging device 14, an operable frame rate, a model number, and the like.
  • the driver signal processing circuit 15 outputs the unique information read from the memory 16 to the system controller 21.
  • the system controller 21 performs various calculations based on the unique information of the electronic scope 100 and generates a control signal.
  • the system controller 21 uses the generated control signal to control the operation and timing of various circuits in the processor 200 so that processing suitable for the electronic scope 100 connected to the processor 200 is performed.
  • the timing controller 22 supplies clock pulses to the driver signal processing circuit 15 according to the timing control by the system controller 21.
  • the driver signal processing circuit 15 drives and controls the solid-state imaging device 14 at a timing synchronized with the frame rate of the video processed on the processor 200 side in accordance with the clock pulse supplied from the timing controller 22.
  • the pre-stage signal processing circuit 26 performs predetermined signal processing such as demosaic processing, matrix calculation, and Y / C separation on the image signal input from the driver signal processing circuit 15 in one frame period, and outputs it to the image memory 27. To do.
  • the image memory 27 buffers the image signal input from the upstream signal processing circuit 26 and outputs it to the downstream signal processing circuit 28 according to the timing control by the timing controller 22.
  • the post-stage signal processing circuit 28 processes the image signal input from the image memory 27 to generate screen data for monitor display, and converts the generated screen data for monitor display into a predetermined video format signal.
  • the converted video format signal is output to the monitor 300. Thereby, the image of the subject is displayed on the display screen of the monitor 300.
  • the electronic endoscope system 1 of the present embodiment has a plurality of observation modes including a normal observation mode and a special observation mode.
  • Each observation mode is switched manually or automatically depending on the subject to be observed. For example, when it is desired to observe the subject illuminated with normal light, the observation mode is switched to the normal observation mode.
  • the normal light is, for example, white light or pseudo white light.
  • White light has a flat spectral intensity distribution in the visible light band.
  • the pseudo-white light has a spectral intensity distribution that is not flat, and light in a plurality of wavelength bands is mixed. For example, when it is desired to obtain a captured image in which a specific living tissue is emphasized by illuminating the subject with special light, the observation mode is switched to the special observation mode.
  • the special light is, for example, narrow band light having a sharp peak at a specific wavelength, and light having high absorbance with respect to a specific living tissue.
  • light of a specific wavelength for example, light having a high absorbance of 415 nm (for example, 415 ⁇ 5 nm) with respect to the surface blood vessel, and light having a high absorbance of 550 nm (for example, 550 ⁇ 5 nm) for the blood vessel in the middle layer deeper than the surface layer.
  • Light and light in the vicinity of 650 nm (for example, 650 ⁇ 5 nm) having a high absorbance with respect to deep blood vessels deeper than the middle layer can be mentioned. Note that the longer the wavelength, the deeper the depth of penetration into the living tissue.
  • the layer region that reaches deeper becomes deeper in the order of narrowband light near 415 nm, 550 nm, and 650 nm.
  • the biological tissue emphasized in the special observation mode is a surface blood vessel will be mainly described.
  • ⁇ Blood containing hemoglobin flows in the surface blood vessels. It is known that hemoglobin has absorbance peaks near wavelengths of 415 nm and 550 nm. Therefore, by irradiating the subject with special light suitable for emphasizing the superficial blood vessels (specifically, light having a higher intensity near the wavelength of 415 nm where the absorbance of hemoglobin is peak than other wavelength bands). A captured image in which the superficial blood vessels are emphasized can be obtained. Special light having a high intensity near the wavelength of 550 nm has a relatively high absorbance even for the surface blood vessels. In other words, special light having a high intensity in the vicinity of a wavelength of 550 nm also contributes to highlighting of the surface blood vessels.
  • the brightness of the photographed image is maintained while maintaining the state where the surface blood vessels are emphasized. Can be brightened.
  • narrowband light special light
  • normal observation mode blood vessels in each layer such as the surface layer, middle layer, and deep layer
  • Narrow band observation suitable for clearly grasping the state can be performed.
  • FIG. 4 shows the spectral intensity distribution of the irradiation light L emitted from the light source device 201 in each observation mode.
  • 4A shows the spectral intensity distribution of the irradiation light L (normal light) in the normal observation mode
  • FIG. 4B shows the spectral intensity distribution of the irradiation light L (special light) in the special observation mode.
  • the horizontal axis of the spectral intensity distribution shown in FIG. 4 indicates the wavelength (nm), and the vertical axis indicates the intensity of the irradiation light L. Note that the vertical axis is standardized so that the maximum intensity value is 1.
  • the first light source unit 111 and the second light source unit 112 are driven to emit light after the blue phosphor 111b is inserted in the optical path.
  • the spectral intensity distribution D111 of light emitted from the first light source unit 111 has intensity peaks at wavelengths of about 415 nm and about 470 nm.
  • a wavelength having the highest intensity among the specific wavelengths is referred to as a peak wavelength.
  • the wavelength having the highest intensity is called the peak wavelength.
  • These two wavelengths are the peak wavelength of the light emitted from the purple LED 111a and the peak wavelength of the spectral intensity distribution of the fluorescence emitted from the blue phosphor 111b.
  • the spectral intensity distribution D112 of light emitted from the second light source unit 112 has peaks at a wavelength of about 450 nm and a wavelength of about 600 nm. These two wavelengths are a peak wavelength of light emitted from the blue LED 112a and a peak wavelength of fluorescence emitted from the yellow phosphor 112b, respectively.
  • spectral intensity distribution D111 shown to Fig.4 (a) has substantially the same peak intensity of purple LED light and blue fluorescence
  • this invention is not limited to this.
  • the ratio of the intensity of the purple LED light emitted from the first light source unit 111 to the intensity of blue fluorescence can be freely changed by changing the type and amount of use of the blue phosphor 111b.
  • the spectral intensity distribution D112 shown in FIG. 4A has a larger ratio of the intensity of yellow fluorescence than that of the blue LED light, but the present invention is not limited to this.
  • the ratio between the blue LED light emitted from the second light source unit 112 and the yellow fluorescence can be freely changed by changing the type and amount of use of the yellow phosphor 112b.
  • the spectral intensity distributions D111 and D112 shown in FIG. 4A have the maximum intensity values set to 1, but the present invention is not limited to this.
  • the intensity ratio of the light emitted from the light source units 111 and 112 can be arbitrarily set according to the subject to be observed, the photographing mode, and the operator's preference.
  • the cutoff wavelength ⁇ 131 of the dichroic mirror 131 is indicated by a dotted line.
  • the dichroic mirror 131 has a cutoff wavelength ⁇ 131 of about 520 nm, transmits light in a wavelength band shorter than the cutoff wavelength ⁇ 131, and reflects light in a wavelength band longer than the cutoff wavelength ⁇ 131. Therefore, in the spectral intensity distribution D111 shown in FIG. 4A, light in the wavelength band indicated by the solid line passes through the dichroic mirror 131, and light in the wavelength band indicated by the broken line is reflected by the dichroic mirror 131. Also, in the spectral intensity distribution D112 shown in FIG.
  • light in a wavelength band equal to or greater than the cutoff wavelength ⁇ 131 indicated by the solid line is reflected by the dichroic mirror 131, and is shorter than the cutoff wavelength ⁇ 131 indicated by the short dotted line.
  • Light in the wavelength band passes through the dichroic mirror 131.
  • the optical paths of the light emitted from the light source units 111 and 112 are synthesized by the dichroic mirror 131, and the light source device 201 emits light having a wide wavelength band from the ultraviolet region (part of the near ultraviolet) to the red region.
  • Light L (normal light) is emitted.
  • the spectral intensity distribution of the irradiation light L (normal light) is the sum of the areas indicated by the solid lines in the spectral intensity distributions D111 and D112 shown in FIG.
  • the first light source unit 111 and the second light source unit 112 are driven to emit light after the blue phosphor 111b is removed from the optical path.
  • the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained.
  • the light emitted from the second light source unit 112 includes light having a wavelength near 550 nm, which is another peak of the absorbance of hemoglobin. Therefore, by driving the second light source unit 112 to emit light together with the first light source unit 111, the brightness of the photographed image can be increased while maintaining the state where the surface blood vessels are emphasized.
  • the blue phosphor 111b is inserted into and removed from the optical path without using an optical filter that transmits only light in a specific wavelength band, so that the irradiation light L is changed between normal light and special light. Switching with. Therefore, it is possible to prevent light in a wavelength band that is not used for observing the subject by the optical filter from being cut and the light use efficiency of the first light source unit from being lowered.
  • the irradiation is performed unless the optical filter has ideal characteristics.
  • the light L is also mixed with blue fluorescence. Since the blue fluorescence is unnecessary light for obtaining a photographed image in which the superficial blood vessels are emphasized, the effect of superficial blood vessels is reduced by mixing the blue light with the irradiation light L. On the other hand, in this embodiment, since the blue fluorescence can be completely suppressed without using an optical filter, it is possible to prevent the enhancement effect of the surface blood vessels from being reduced.
  • the light paths of the light emitted from the light source units 111 and 112 are combined by the dichroic mirror 131. At this time, since the wavelength bands of the light emitted from the light source units 111 and 112 are different from each other, the loss of the light amount can be minimized when the optical paths in the dichroic mirror 131 are combined.
  • the special observation mode when using an optical filter that substantially transmits only light in a specific wavelength band as in the prior art, it is necessary to waste light other than the specific wavelength band.
  • the light utilization efficiency of the device is low.
  • light that is not used as irradiation light L by combining optical paths in the dichroic mirror 131 (light in a region indicated by a broken line in FIG. 4) Is smaller in amount of light than the light used as the irradiation light L (the light in the region indicated by the solid line in FIG. 4). Therefore, in the light source device 201 of the present embodiment, it is not necessary to wastefully emit light in a wavelength band that is not irradiated on the subject, and the light use efficiency can be increased as compared with the related art.
  • the distance from the distal end portion of the electronic scope 100 to the subject is typically far, Strength is lowered.
  • the light source device 201 of the present embodiment does not use an optical filter in the special observation mode and has high light use efficiency, it is possible to increase the intensity of irradiation light irradiated on the subject. Therefore, a bright captured image can be obtained even when observing a site such as the stomach.
  • the peak intensities of the spectral intensity distributions D111 and D112 are all set to 1, but the present invention is not limited to this. It is not limited to.
  • the second light source unit 112 may be driven to emit light so that the drive current is smaller and the intensity is lower than that in the normal observation mode.
  • the intensity around the wavelength of 415 nm, which is the peak of hemoglobin absorbance is relatively higher than the intensity of other wavelength bands (that is, becomes narrowband light), and a captured image in which the surface blood vessels are more emphasized is obtained. Can do.
  • an endoscope light source device according to a second embodiment of the present invention will be described.
  • the light source device according to the second embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
  • FIG. 5 is a block diagram conceptually showing only the light source unit and the dichroic mirror in the light source device 202 according to the second embodiment.
  • the light source device 202 includes a first light source unit 211, a second light source unit 212, and a first dichroic mirror 231.
  • the light source units 211 and 212 are individually controlled to emit light by a first light source drive circuit and a second light source drive circuit (not shown).
  • the first light source unit 211 has a purple LED 211a that emits light in a purple wavelength band (for example, a wavelength of 395 to 435 nm) and a blue phosphor 211b.
  • the blue phosphor 211b is excited by the purple LED light emitted from the purple LED 211a and emits fluorescence in a blue wavelength band (for example, a wavelength of 430 to 550 nm).
  • the blue phosphor 211b is supported by an unillustrated phosphor insertion / extraction mechanism so that the blue phosphor 211b can be inserted into and removed from the optical path of the purple LED light emitted from the purple LED 211a. Since the blue phosphor 211b is separate from the purple LED 211a, the blue phosphor 211b and the purple LED 211a are shown as separate blocks in FIG.
  • the second light source unit 212 includes a blue LED, a green phosphor, and a red phosphor that emit light in a blue wavelength band (for example, a wavelength of 420 to 480 nm).
  • the green phosphor is excited by blue LED light emitted from the blue LED, and emits fluorescence in a green wavelength band (for example, a wavelength of 510 to 630 nm).
  • the red phosphor is excited by the blue LED light emitted from the blue LED and emits fluorescence in the red wavelength band (for example, the wavelength is 550 to 750 nm).
  • the green phosphor and the red phosphor may be arranged side by side along the emission direction of blue LED light, or may be arranged side by side in a direction perpendicular to the emission direction of blue LED light.
  • the green phosphor and the red phosphor may be prepared as a single phosphor by mixing the materials.
  • a collimating lens (not shown) is arranged in front of the light source units 211 and 212 in the emission direction.
  • the light emitted from the first light source unit 211 is converted into parallel light by the collimator lens and is incident on the dichroic mirror 231.
  • the light emitted from the second light source unit 212 is converted into parallel light by the collimator lens and is incident on the dichroic mirror 231.
  • the dichroic mirror 231 combines the optical path of the light emitted from the first light source unit 211 and the optical path of the light emitted from the second light source unit 212.
  • the light whose optical path is synthesized by the dichroic mirror 231 is emitted from the light source device 202 as irradiation light L.
  • FIG. 6 is a view similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 202 in each observation mode.
  • both the first light source unit 211 and the second light source unit 212 are driven to emit light after the blue phosphor 211b is inserted in the optical path.
  • the spectral intensity distribution D211 of light emitted from the first light source unit 211 has peaks at a wavelength of about 415 nm and a wavelength of about 470 nm. These two wavelengths are a peak wavelength of light emitted from the purple LED 211a and a peak wavelength of fluorescence emitted from the blue phosphor 211b, respectively.
  • the spectral intensity distribution D212 of light emitted from the second light source unit 212 has peaks at wavelengths of about 450 nm, about 550 nm, and about 650 nm. These three wavelengths are respectively the peak wavelengths of blue LED light, fluorescence emitted by the green phosphor, and fluorescence emitted by the red phosphor.
  • the cutoff wavelength ⁇ 231 of the dichroic mirror 231 is indicated by a dotted line.
  • the dichroic mirror 231 has a cutoff wavelength ⁇ 231 of about 510 nm, transmits light in a wavelength band shorter than the cutoff wavelength ⁇ 231, and reflects light in a wavelength band longer than the cutoff wavelength ⁇ 231. Therefore, in the spectral intensity distribution D211 shown in FIG. 4A, light in the wavelength band indicated by the solid line passes through the dichroic mirror 231 and light in the wavelength band indicated by the broken line is reflected by the dichroic mirror 231. Also, in the spectral intensity distribution D212 shown in FIG. 4A, light in the wavelength band indicated by the solid line is reflected by the dichroic mirror 231 and light in the wavelength band indicated by the broken line passes through the dichroic mirror 231.
  • the optical path of the light emitted from each of the light source units 211 and 212 is synthesized by the dichroic mirror 231, and the light source device 202 emits light having a wide wavelength band from the ultraviolet region (part of near ultraviolet) to the red region.
  • Light L normal light
  • the spectral intensity distribution of the irradiation light L (normal light) is the sum of the areas indicated by the solid lines in the spectral intensity distributions D211 and D212 shown in FIG.
  • both the first light source unit 211 and the second light source unit 212 are driven to emit light after the blue phosphor 211b is removed from the optical path. .
  • the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained.
  • the second light source unit 212 has two phosphors, a green phosphor and a red phosphor. Therefore, the spectral intensity distribution of the irradiation light L (normal light) when the electronic endoscope system 1 is in the normal observation mode is more visible than when the second light source unit 212 has one phosphor. It approaches flat in the area. Thereby, in the normal observation mode, the subject can be illuminated with the irradiation light L (normal light) close to natural white light.
  • the light source device according to the third embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
  • FIG. 7 is a block diagram conceptually showing only the light source unit and the dichroic mirror in the light source device 203 according to the third embodiment.
  • the light source device 203 includes a first light source unit 311, a second light source unit 312, a third light source unit 313, a first dichroic mirror 331, and a second dichroic mirror 332.
  • the light source units 311 to 313 are individually controlled to emit light by first to third light source driving circuits (not shown).
  • the light source device 203 has a configuration in which a third light source unit 313 and a second dichroic mirror 332 are added to the light source device 201 according to the first embodiment.
  • the characteristics of the first light source unit 311, the second light source unit 312, and the dichroic mirror 331 are the characteristics of the first light source unit 111, the second light source unit 112, and the dichroic mirror 131 of the first embodiment, respectively.
  • the third light source unit 313 is a red LED that emits light in a red wavelength band (for example, a wavelength of 620 to 680 nm).
  • the cut-off wavelength ⁇ 332 of the dichroic mirror 332 is 630 nm.
  • the dichroic mirror 332 transmits light in a wavelength band shorter than the cutoff wavelength and reflects light in a wavelength band equal to or greater than the cutoff wavelength.
  • FIG. 8 is a diagram similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 203 in each observation mode.
  • the first to third light source units 311 to 313 are driven to emit light after the blue phosphor 311b is inserted in the optical path.
  • the spectral intensity distribution of the irradiation light L in the third embodiment is obtained by adding the spectral intensity distribution D313 of the red LED 313 to the irradiation light L in the first embodiment.
  • the light source device 203 of the third embodiment has a dichroic mirror 332 unlike the first embodiment, of the light emitted from the second light source unit 312, the light source device 203 of the dichroic mirror 332.
  • the optical path of light having a wavelength longer than the cutoff wavelength ⁇ 332 (630 nm) is not synthesized by the dichroic mirror 332 and is not emitted as the irradiation light L.
  • the optical path of light having a wavelength shorter than the cutoff wavelength ⁇ 332 is not synthesized by the dichroic mirror 332 and is not emitted as the irradiation light L.
  • the light source device 203 of the third embodiment has a red LED 313. Therefore, the spectral intensity distribution of the irradiation light L (normal light) in the case where the electronic endoscope system 1 is in the normal observation mode is closer to flat in the visible region than in the configuration without the red LED 313. Thereby, in the normal observation mode, the subject can be illuminated with the irradiation light L (normal light) close to natural white light.
  • the first phosphor unit 311 and the second light source unit 312 are driven to emit light after the blue phosphor 211b is removed from the optical path, and the third light source unit 312 is driven to emit light.
  • the light source unit 313 is not driven to emit light.
  • the light source device 203 of the third embodiment has three light source units 311 to 313 having different wavelength bands and capable of individually controlling light emission. Therefore, the spectral intensity distribution of the irradiation light L can be finely controlled by selecting a light source unit to be driven for light emission from among the three light source units 311 to 313 and individually controlling the drive current during the light emission drive.
  • an endoscope light source device according to a fourth embodiment of the present invention will be described.
  • the light source device according to the fourth embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
  • FIG. 9 is a block diagram conceptually showing only the light source unit and the dichroic mirror in the light source device 204 according to the fourth embodiment.
  • the light source device 204 includes a first light source unit 411, a second light source unit 412, a third light source unit 413, a first dichroic mirror 431, and a second dichroic mirror 432.
  • the light source units 411 to 413 are individually controlled to emit light by first to third light source driving circuits (not shown).
  • the light source device 204 according to the fourth embodiment is obtained by replacing the second light source unit 312 in the light source device 203 according to the third embodiment with an LED having no phosphor. .
  • the second light source unit 412 is a green LED that emits light in a green wavelength band (for example, a wavelength of 520 to 580 nm).
  • the characteristics of the first and third light source units 411 and 413 and the first and second dichroic mirrors 431 and 432 are the same as those of the first and third light source units 311 and 313 and the first and second light source units 311 and 313 of the third embodiment.
  • the characteristics of the second dichroic mirrors 331 and 332 need not be the same.
  • FIG. 10 is a view similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 204 in each observation mode.
  • the first to third light source units 311 to 313 are driven to emit light after the blue phosphor 411b is inserted in the optical path.
  • the spectral intensity distribution D411 of light emitted from the first light source unit 411 has peaks at a wavelength of about 415 nm and a wavelength of about 470 nm. These two wavelengths are a peak wavelength of light emitted from the purple LED 411a and a peak wavelength of fluorescence emitted from the blue phosphor 411b, respectively.
  • the spectral intensity distribution D412 of the light emitted from the second light source unit 412 has an intensity distribution with a peak wavelength of about 550 nm.
  • the spectral intensity distribution D413 of light emitted from the third light source unit 413 has an intensity distribution with a peak wavelength of about 640 nm.
  • the cutoff wavelengths ⁇ 431 and ⁇ 432 of the dichroic mirrors 431 and 432 are indicated by dotted lines. Cutoff wavelengths ⁇ 431 and ⁇ 432 are 510 nm and 590 nm, respectively. Any of the dichroic mirrors 431 and 432 transmits light having a wavelength band shorter than the cutoff wavelength, and reflects light having a wavelength band equal to or greater than the cutoff wavelength.
  • the dichroic mirrors 431 and 432 the optical paths of the light emitted from the light source units 411 to 413 are combined and emitted as irradiation light L (normal light). By irradiating the subject with the irradiation light L (normal light), a normal color photographed image can be obtained.
  • the first light source unit 411 and the second light source unit 412 are driven to emit light after the blue phosphor 411b is removed from the optical path, and the third The light source unit 413 is not driven to emit light.
  • the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained. Obtainable.
  • an endoscope light source device according to a fifth embodiment of the present invention will be described.
  • the light source device according to the fifth embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
  • FIG. 11 is a block diagram conceptually showing only the light source unit and the dichroic mirror in the light source device 205 according to the fifth embodiment.
  • the light source device 205 includes a first light source unit 511, a second light source unit 512, and a first dichroic mirror 531.
  • the light source units 511 and 512 are individually controlled to emit light by first and second light source driving circuits (not shown).
  • the first light source unit 511 includes a phosphor LED 511a and a blue phosphor 511b.
  • the phosphor LED 511a has a purple LED that emits light in a purple wavelength band (for example, a wavelength of 395 to 435 nm), and a green phosphor attached on the light emitting surface of the purple LED.
  • the green phosphor is excited by the purple LED light emitted from the purple LED, and emits fluorescence in the green wavelength band (for example, the wavelength is 510 to 630 nm).
  • the blue phosphor 511b is excited by the violet LED light emitted from the violet LED, and emits fluorescence in a blue wavelength band (for example, the wavelength is 430 to 550 nm).
  • the blue phosphor 511b is supported by an unillustrated phosphor insertion / extraction mechanism so as to be insertable / removable with respect to the optical path of the light emitted from the phosphor LED 511a.
  • the second light source unit 512 is a red LED that emits light in a red wavelength band (for example, a wavelength of 620 to 680 nm).
  • the dichroic mirror 531 combines the optical path of the light emitted from the first light source unit 511 and the optical path of the light emitted from the second light source unit 512.
  • the light whose optical path is synthesized by the dichroic mirror 531 is emitted from the light source device 205 as irradiation light L.
  • FIG. 12 is a view similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 205 in each observation mode.
  • the first and second light source units 511 and 512 are driven to emit light after the blue phosphor 511b is inserted in the optical path.
  • the spectral intensity distribution D511 of light emitted from the first light source unit 511 has peaks at wavelengths of about 415 nm, about 470 nm, and about 550 nm. These three wavelengths are respectively the peak wavelengths of the purple LED light emitted from the purple LED, the fluorescence emitted from the blue phosphor 511b, and the fluorescence emitted from the green phosphor.
  • the spectral intensity distribution D512 of light emitted from the second light source unit 512 has an intensity distribution with a wavelength of about 650 nm as a peak wavelength.
  • the cutoff wavelength ⁇ 531 of the dichroic mirror 531 is indicated by a dotted line.
  • the cutoff wavelength ⁇ 531 is 620 nm.
  • the dichroic mirror 531 transmits light in a wavelength band shorter than the cutoff wavelength, and reflects light in a wavelength band equal to or greater than the cutoff wavelength.
  • the optical paths of the light emitted from the first light source unit 511 and the second light source unit 512 are combined and emitted as irradiation light L.
  • irradiation light L normal light
  • the blue phosphor 511b is removed from the optical path, and only the first light source unit 511 is driven to emit light, and the second light source unit 512 emits light. Not driven.
  • the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained. Obtainable.
  • the green phosphor of the first light source unit 511 is mounted on the light emitting surface of the purple LED, but the present invention is not limited to this.
  • the green phosphor of the first light source unit 511 may be disposed so as to be insertable / removable on the optical path of the light emitted from the purple LED.
  • the spectral intensity characteristic of the irradiation light L irradiated to the subject can be changed by inserting or removing the green phosphor on the optical path.
  • FIG. 13 is a block diagram conceptually showing only the light source unit and the dichroic mirror in the light source device 206 according to the sixth embodiment.
  • the light source device 206 includes a first light source unit 611, a second light source unit 612, and a first dichroic mirror 631.
  • the light source units 611 and 612 are individually controlled to emit light by first and second light source driving circuits (not shown).
  • the first light source unit 611 has a phosphor LED 611a and a red phosphor 611b.
  • the phosphor LED 611a includes a blue LED that emits light in a blue wavelength band (for example, a wavelength of 430 to 490 nm), and a green phosphor attached on the light emitting surface of the blue LED.
  • the green phosphor is excited by blue LED light emitted from the blue LED, and emits fluorescence in a green wavelength band (for example, a wavelength of 510 to 630 nm).
  • the red phosphor 611b is excited by the blue LED light emitted from the blue LED, and emits fluorescence in the red wavelength band (for example, the wavelength is 550 to 750 nm).
  • the red phosphor 611b is supported by an unillustrated phosphor insertion / extraction mechanism so as to be insertable / removable with respect to the optical path of light emitted from the phosphor LED 611a.
  • the second light source unit 612 is a purple LED that emits light in a purple wavelength band (for example, a wavelength of 395 to 435 nm).
  • the dichroic mirror 631 combines the optical path of the light emitted from the first light source unit 611 and the optical path of the light emitted from the second light source unit 612.
  • the light whose optical path is synthesized by the dichroic mirror 631 is emitted from the light source device 206 as irradiation light L.
  • FIG. 14 is a view similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 206 in each observation mode.
  • the first and second light source units 611 and 612 are driven to emit light after the red phosphor 611b is inserted in the optical path.
  • the spectral intensity distribution D611 of light emitted from the first light source unit 611 has peaks at wavelengths of about 460 nm, about 550 nm, and about 650 nm. These three wavelengths are the peaks of the spectral intensity distribution of the blue LED light emitted from the phosphor LED 611a, the green fluorescence, and the fluorescence emitted by the red phosphor 611b, respectively.
  • the spectral intensity distribution D612 of light emitted from the second light source unit 612 has an intensity distribution having a peak at about 415 nm.
  • the cutoff wavelength ⁇ 631 of the dichroic mirror 631 is indicated by a dotted line.
  • the cutoff wavelength ⁇ 631 is 440 nm.
  • the dichroic mirror 631 transmits light having a wavelength band shorter than the cutoff wavelength, and reflects light having a wavelength band equal to or greater than the cutoff wavelength.
  • the optical paths of the light emitted from the first light source unit 611 and the second light source unit 612 are combined and emitted as the irradiation light L.
  • the irradiation light L normal light
  • the first and second light source units 611 and 612 are driven to emit light after the red phosphor 611b is removed from the optical path.
  • the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained.
  • an endoscope light source device according to a seventh embodiment of the present invention will be described.
  • the light source device according to the seventh embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
  • FIG. 15 is a block diagram conceptually showing only the light source unit in the light source device 207 according to the seventh embodiment.
  • the light source device 207 includes a light source unit 711.
  • the light source unit 711 is controlled to emit light by a light source driving circuit (not shown).
  • the light source unit 711 includes a phosphor LED 711a, a blue phosphor 711b, and a red phosphor 711c.
  • the phosphor LED 711a includes a purple LED that emits light in a purple wavelength band (for example, a wavelength of 395 to 435 nm) and a green phosphor that is attached on the light emitting surface of the purple LED. This green phosphor is excited by the purple LED light emitted from the purple LED, and emits fluorescence in the green wavelength band (for example, the wavelength is 510 to 630 nm).
  • the blue phosphor 711b is excited by the purple LED light emitted from the purple LED, and emits fluorescence in a blue wavelength band (for example, a wavelength of 430 to 550 nm).
  • the red phosphor 711c is excited by the purple LED light emitted from the purple LED, and emits fluorescence in the red wavelength band (for example, the wavelength is 550 to 750 nm).
  • the blue phosphor 711b and the red phosphor 711c are individually inserted into or removed from the optical path of light emitted from the phosphor LED 711a by a phosphor insertion / extraction mechanism (not shown).
  • FIG. 16 is a view similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 207 in each observation mode.
  • the light source unit 711 is driven to emit light after the blue phosphor 711b and the red phosphor 711c are inserted in the optical path.
  • the spectral intensity distribution D711 of light emitted from the light source unit 711 has peaks at wavelengths of about 415 nm, about 470 nm, about 550 nm, and about 650 nm. These four wavelengths are the peak wavelengths of the purple LED light emitted from the phosphor LED 711a, the fluorescence emitted from the blue phosphor 711b, the fluorescence emitted from the green phosphor of the phosphor LED 711a, and the fluorescence emitted from the red phosphor 711c.
  • the light emitted from the light source unit 711 is irradiated to the subject as irradiation light L (normal light). Thereby, a normal color photographed image can be obtained.
  • the light source unit 711 is driven to emit light after the blue phosphor 711b and the red phosphor 711c are removed from the optical path.
  • the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained.
  • the configuration of the light source device 207 can be simplified.
  • the light source unit 711 has three phosphors of red, blue, and green.
  • the phosphor has a wider wavelength band than the light emitted from the LED. Therefore, the spectral intensity distribution of the irradiation light L (normal light) when the electronic endoscope system 1 is in the normal observation mode is more visible than when the light source unit 711 has one or two phosphors. It approaches flat in the area. Accordingly, the subject can be illuminated with the irradiation light L (normal light) close to natural white light.
  • Embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention.
  • the embodiment of the present invention also includes contents appropriately combined with embodiments or the like clearly shown in the specification or obvious embodiments.
  • an LED is assumed as the solid state light emitting device.
  • the present invention is not limited to this, and it is also possible to employ LD (Laser Diode) as a solid state light emitting device.
  • FIG. 17 shows the spectral intensity distribution of the irradiation light L emitted from the light source device 204 in the modification of the fourth embodiment.
  • there are four observation modes normal observation mode, first special observation mode, second special observation mode, and third special observation mode.
  • FIG. 17A shows the spectral intensity distribution of the irradiation light L (normal light) in the normal observation mode
  • FIG. 17B shows the spectral intensity distribution of the irradiation light L (special light) in the first special observation mode
  • FIG. 17C shows the spectral intensity distribution of the irradiation light L (special light) in the second special observation mode
  • FIG. 17D shows the irradiation light L (special light) in the third special observation mode.
  • the spectral intensity distribution is shown.
  • the horizontal axis of the spectral intensity distribution shown in FIG. 17 indicates the wavelength (nm), and the vertical axis indicates the intensity of the irradiation light L. Note that the vertical axis is standardized so that the maximum intensity value is 1.
  • the first light source unit 411 is driven to emit light
  • the second light source unit 412 and the third light source unit 412 are driven.
  • the light source unit 413 is not driven to emit light.
  • the ratio of light in the vicinity of the wavelength of 415 nm, which is the absorption peak of hemoglobin, of the irradiation light L (special light) is relatively high (that is, narrowband light having a peak only in the vicinity of the wavelength of 415 nm).
  • a captured image in which the surface blood vessels are emphasized can be obtained.
  • the second light source unit 412 is driven to emit light, and the first light source unit 411 and the third light source unit 411b are driven.
  • the light source unit 413 is not driven to emit light.
  • the ratio of light in the vicinity of the wavelength of 550 nm, which is the absorption peak of hemoglobin, of the irradiation light L (special light) is relatively high (that is, the light is narrowband having a peak only in the vicinity of the wavelength of 550 nm).
  • a captured image in which the middle layer blood vessel is emphasized can be obtained.
  • the third light source unit 413 is driven to emit light, and the first light source unit 411 and the second light source unit 411 are driven.
  • the light source unit 412 is not driven to emit light.
  • the ratio of light in the vicinity of the wavelength of 650 nm, which is the peak of the absorbance of hemoglobin, in the irradiated light L (special light) is relatively high (that is, narrowband light having a peak only in the vicinity of the wavelength of 650 nm).
  • a captured image in which deep blood vessels are emphasized can be obtained.
  • the present modification it is possible to obtain a photographed image that mainly emphasizes the surface blood vessels in the first special observation mode, and obtain a photographed image that mainly emphasizes the middle-layer blood vessels in the second special observation mode.
  • the third special observation mode it is possible to obtain a photographed image mainly emphasizing deep blood vessels.
  • the first to third special observation modes are switched to obtain a desired layer area (surface layer in the first special observation mode, middle layer in the second special observation mode, and deep layer in the third special observation mode. ) Can be observed with emphasis on blood vessels.
  • the blue phosphor 711b and the red phosphor 711c are inserted on the optical path in the normal observation mode, and the blue phosphor 711b and the red phosphor 711c are removed from the optical path in the special observation mode. Therefore, in the seventh embodiment, the blue phosphor 711b and the red phosphor 711c perform the same insertion / extraction operation (linked movement) according to the observation mode. On the other hand, in the modification of the seventh embodiment, the blue phosphor 711b and the red phosphor 711c do not perform the same insertion / extraction operation according to the observation mode, but perform another insertion / extraction operation.
  • two special observation modes are further added.
  • the blue phosphor 711b is removed from the optical path, and the phosphor LED 711a and the red phosphor 711c are driven to emit light.
  • the red phosphor 711c is removed from the optical path, and the phosphor LED 711a and the blue phosphor 711b are driven to emit light.
  • a plurality of phosphors (blue phosphor 711b, red phosphor 711c) excited by light emitted from phosphor LED 711a are arranged side by side on the optical path of phosphor LED 711a, and each fluorescence
  • the body performs another insertion / extraction operation according to the observation mode (the red phosphor 711c is removed when the blue phosphor 711b is inserted, and the blue phosphor 711b is removed when the red phosphor 711c is inserted).
  • a configuration in which a narrow-band observation image in which a blood vessel is emphasized using special light (narrow-band light) is generated and displayed is employed.
  • a configuration is adopted in which biological information (specifically, oxygen saturation) of a subject is quantitatively analyzed and imaged based on a plurality of images taken with light having different wavelength ranges. Also good.
  • FIG. 18 shows a block diagram of a light source device 208 according to another embodiment. Another embodiment will be described based on the first embodiment for convenience. As shown in FIG. 18, the light source device 208 is different from the light source device 201 according to the first embodiment in that the second light source unit 112 is replaced with the second light source unit 112 ′ and the rotary turret 400 and the filter are rotated. The mechanism 430 is added.
  • FIG. 19 is a block diagram conceptually showing only a light source unit, a dichroic mirror, and a rotary turret in a light source device 208 according to another embodiment.
  • the second light source unit 112 ' has a blue LED 112a and does not have a yellow phosphor 112b.
  • FIG. 20 is a diagram showing a configuration of the rotary turret 400.
  • a motor shaft 432 of a DC motor constituting the filter rotation mechanism 430 is press-fitted into the bearing hole formed at the center of the rotary turret 400.
  • the rotary turret 400 is supported by a filter rotating mechanism 430 so as to be rotatable around a motor shaft 432.
  • the filter rotation mechanism 430 since a well-known structure is employ
  • the rotary turret 400 has four openings arranged in the circumferential direction. Different phosphors are embedded in the respective openings. Specifically, a yellow phosphor 112b ', a first oxygen saturation observation phosphor Fs1, a second oxygen saturation observation phosphor Fs2, and a narrow band observation phosphor Fs3 are embedded.
  • the oxygen saturation distribution image in the oxygen saturation observation mode is displayed. Is possible.
  • FIG. 21 shows an absorption spectrum of hemoglobin near 550 nm.
  • Hemoglobin has a strong absorption band called a Q band derived from porphyrin near 550 nm.
  • the absorption spectrum of hemoglobin varies depending on the oxygen saturation (the ratio of oxygenated hemoglobin in the total hemoglobin).
  • the solid line waveform in FIG. 21 shows an absorption spectrum when the oxygen saturation is 100% (that is, oxygenated hemoglobin HbO), and the long broken line waveform is when the oxygen saturation is 0% (that is, reduction).
  • the absorption spectrum of hemoglobin Hb is shown.
  • the short dashed line shows the absorption spectrum of hemoglobin (a mixture of oxygenated hemoglobin and reduced hemoglobin) at intermediate oxygen saturation (10, 20, 30,... 90%).
  • oxygenated hemoglobin and reduced hemoglobin have different peak wavelengths. Specifically, oxygenated hemoglobin has an absorption peak P1 near a wavelength of 542 nm and an absorption peak P3 near a wavelength of 578 nm. On the other hand, reduced hemoglobin has an absorption peak P2 near 558 nm.
  • FIG. 21 is a two-component absorption spectrum in which the sum of the concentrations of the components (oxygenated hemoglobin and deoxyhemoglobin) is constant. Therefore, the absorption is constant regardless of the concentration of each component (that is, oxygen saturation). Iso-absorption points E1, E2, E3, E4 appear.
  • wavelength region sandwiched between the equal absorption points E1 and E2 is referred to as “wavelength region R1”
  • the wavelength region sandwiched between the equal absorption points E2 and E3 is referred to as “wavelength region R2”
  • wavelength region R3 A wavelength region sandwiched between the absorption points E3 and E4 is referred to as a “wavelength region R3”.
  • a wavelength region sandwiched between the isosbestic points E1 and E4 (that is, a combination of the wavelength regions R1, R2, and R3) is referred to as a “wavelength region R0”.
  • the wavelength range R0 is 528 nm to 584 nm.
  • the wavelength range R2 is 546 nm to 570 nm.
  • the absorption monotonously increases or decreases with respect to the oxygen saturation between adjacent isosbestic points. Further, between adjacent isosbestic points, the absorption of hemoglobin changes almost linearly with respect to the oxygen saturation.
  • the absorption A R1, A R3 of hemoglobin in the wavelength range R1, R3 is linearly and monotonously increases with respect to the concentration of oxygenated hemoglobin (oxygen saturation)
  • the oxygen saturation can be calculated from the value of the index X.
  • the first oxygen saturation observation phosphor Fs1 is a phosphor excited by light emitted from the blue LED 112a and emits fluorescence in the 550 nm band. As shown in FIG. 21, the first oxygen saturation observation phosphor Fs1 emits fluorescence in the wavelength region (that is, wavelength region R0) from the isosbestic points E1 to E4, and the fluorescence in other wavelength regions. Does not emit.
  • the second oxygen saturation observation phosphor Fs2 is a phosphor excited by light emitted from the blue LED 112a, and emits fluorescence in a wavelength region from the isoabsorption points E2 to E3 (that is, the wavelength region R2). , Does not emit fluorescence in other wavelength regions.
  • the yellow phosphor 112b ' is a phosphor excited by light emitted from the blue LED 112a and emits the same fluorescence as the yellow phosphor 112b.
  • the narrow-band observation phosphor Fs3 emits fluorescence in a 650 nm band (630 to 650 nm) having high absorbance with respect to a specific biological tissue (mainly deep blood vessels) and does not emit fluorescence in other wavelength regions.
  • another color LED such as a purple LED or a green LED
  • the first oxygen saturation observation phosphor Fs1 emits fluorescence in the wavelength region R0 by the light emitted from the other color LEDs.
  • the second phosphor Ss for observing the degree of oxygen saturation Fs2 emits fluorescence in the wavelength region R2 by the light emitted from the other color LED.
  • the yellow phosphor 112b 'emits the same fluorescence as the yellow phosphor 112b by the light emitted from the other color LEDs.
  • the rotary turret 400 includes a plurality of phosphors having different emission characteristics (the yellow phosphor 112b ′, the first oxygen saturation observation phosphor Fs1, the second oxygen saturation observation phosphor). Fs2, narrowband observation phosphor Fs3) are arranged.
  • the blue phosphor 111b is inserted in the optical path, the first light source unit 111 and the second light source unit 112 ′ are driven to emit light, and the yellow phosphor 112b ′ is irradiated with the irradiation light L.
  • the rotary turret 400 stops in a state where it is located on the optical path. Therefore, in the normal observation mode, the irradiation light L (normal light) having the same spectral characteristics (see FIG. 4A) as in the first embodiment is emitted. By irradiating the subject with the irradiation light L (normal light), a normal color photographed image can be obtained.
  • the first light source unit 111 and the second light source unit 112 ′ are driven to emit light, and the yellow phosphor 112b ′ is irradiated with the irradiation light L.
  • the rotary turret 400 stops in a state where it is located on the optical path. Therefore, even in the special observation mode, the irradiation light L (normal light) having the same spectral characteristics (see FIG. 4B) as in the first embodiment is emitted.
  • the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiated light L (special light) is relatively high (that is, narrow-band light), and imaging in which mainly the surface blood vessels are emphasized An image can be obtained.
  • the first light source unit 111 and the second light source unit 112 ′ are driven to emit light, and the yellow phosphor 112b ′ and the first phosphor
  • Each of the phosphors for oxygen saturation observation Fs1, the second oxygen saturation observation phosphor Fs2, and the narrowband observation phosphor Fs3 is synchronized with the frame rate on the optical path of the irradiation light L (synchronized with the imaging period). ),
  • the rotary turret 400 is rotationally driven by the filter rotating mechanism 430 at a period of one rotation in four frames.
  • the first light source unit 111 may not be driven to emit light.
  • a through hole 402 is formed in the rotary turret 400.
  • the system controller 21 detects and adjusts the rotational phase of the rotary turret 400 based on the detection timing of the through hole 402 by the photo interrupter 434 constituting the filter rotating mechanism 430. Thereby, the rotary turret 400 is rotationally driven at a constant speed (a period of one rotation in four frames) during the oxygen saturation observation mode.
  • the subject corresponds to each phosphor of the yellow phosphor 112b ′, the first oxygen saturation observation phosphor Fs1, the second oxygen saturation observation phosphor Fs2, and the narrow band observation phosphor Fs3.
  • the irradiated light L fluorescence
  • the post-stage signal processing circuit 28 includes each of the yellow phosphor 112b ′, the first oxygen saturation observation phosphor Fs1, the second oxygen saturation observation phosphor Fs2, and the narrow band observation phosphor Fs3.
  • Image signals corresponding to the irradiation light L through the body are sequentially input.
  • the post-stage signal processing circuit 28 uses the above equation (1) to output the image signal corresponding to the first oxygen saturation observation phosphor Fs1 input from the image memory 27 and the second oxygen saturation observation phosphor.
  • An index X is calculated from the image signal corresponding to Fs2.
  • a non-volatile memory (not shown) provided in the post-stage signal processing circuit 28 stores a numerical table showing a quantitative relationship between the oxygen saturation of hemoglobin and the value of the index X, which are experimentally acquired in advance.
  • the post-stage signal processing circuit 28 refers to this numerical table and obtains the oxygen saturation SatO 2 (x, y) corresponding to the value of the index X calculated using the above equation (1).
  • the post-stage signal processing circuit 28 uses the data obtained by multiplying the acquired oxygen saturation SatO 2 (x, y) by a predetermined constant as the pixel value of each pixel (x, y) (oxygen saturation distribution image data). ) Is generated.
  • the post-stage signal processing circuit 28 generates narrowband observation image data using an image signal corresponding to the narrowband observation phosphor Fs3 input from the image memory 27.
  • the post-stage signal processing circuit 28 converts the oxygen saturation distribution image data into a predetermined video format signal.
  • the converted video format signal is output to the monitor 300. Thereby, the oxygen saturation distribution image is displayed on the display screen of the monitor 300.
  • an oxygen saturation distribution image can be obtained without using a dimming means such as an optical filter. For this reason, the light use efficiency is higher than that in the case where the light reducing means is used.
  • the post-stage signal processing circuit 28 may convert the narrowband observation image data into a predetermined video format signal in addition to the oxygen saturation distribution image data.
  • a narrow-band observation image is displayed on the display screen of the monitor 300 in addition to the oxygen saturation distribution image.

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Abstract

This endoscope light source device is constituted by: a first light source unit provided with a first solid state light-emitting element that projects light within a first wavelength band and a first fluorescent body that is excited by the light in the first wavelength band and emits first fluorescent light; and a fluorescent body inserting/removing means supporting the first fluorescent body such that the first fluorescent body can be inserted and removed with respect to the light path of the light projected from the first solid state light-emitting element. When the first fluorescent body is inserted into the light path by the fluorescent body inserting/removing means, the light in the first wavelength band and the first fluorescent light are supplied to the endoscope projected on the same light path. Additionally, when the first fluorescent body is removed from the light path, the light in the first wavelength band is projected and supplied to the endoscope.

Description

内視鏡用光源装置及び内視鏡システムEndoscope light source device and endoscope system
　本発明は、被写体に光を照射する内視鏡用光源装置及び内視鏡システムに関する。 The present invention relates to an endoscope light source device and an endoscope system for irradiating a subject with light.
　照射光の分光強度特性を変化させ、特殊な画像を撮影することが可能な内視鏡システムが知られている。例えば国際公開第２０１２／１０８４２０号パンフレット（以下、「特許文献１」と記す。）に、この種の内視鏡システムに使用される光源装置の具体的構成が記載されている。 An endoscope system that can change the spectral intensity characteristics of irradiated light and take a special image is known. For example, a pamphlet of International Publication No. 2012/108420 (hereinafter referred to as “Patent Document 1”) describes a specific configuration of a light source device used in this type of endoscope system.
　特許文献１に記載の内視鏡システムは、２つの発光ダイオード（ＬＥＤ：Light Emitting Diode）と光学フィルタが搭載された光源装置を備えている。２つのＬＥＤの内、一方は紫色の波長帯域の光を射出する紫色ＬＥＤである。また、他方のＬＥＤは、青色ＬＥＤと黄色の蛍光体を有する蛍光体ＬＥＤであり、青色のＬＥＤ光と黄色の蛍光を混色することにより、擬似的な白色光を射出する。光学フィルタは、特定の生体組織に対して高い吸光度を有する波長帯域の光のみを通過させる波長選択フィルタであり、蛍光体ＬＥＤから射出される光の光路上に挿抜可能である。 The endoscope system described in Patent Document 1 includes a light source device on which two light emitting diodes (LEDs) are mounted and an optical filter. One of the two LEDs is a purple LED that emits light in a purple wavelength band. The other LED is a phosphor LED having a blue LED and a yellow phosphor, and emits pseudo white light by mixing blue LED light and yellow fluorescence. The optical filter is a wavelength selection filter that passes only light in a wavelength band having high absorbance with respect to a specific living tissue, and can be inserted into and extracted from the optical path of light emitted from the phosphor LED.
　特許文献１に記載の光源装置では、光学フィルタが光路上から抜去されているときは、蛍光体ＬＥＤから射出された光が、波長帯域が制限されることなく、白色光として被写体に照射される。一方、光学フィルタが光路上に挿入されているときは、蛍光体ＬＥＤから射出され波長帯域が制限された照射光と、紫色ＬＥＤから射出された照射光の両方が被写体に照射される。このように、照射光の分光強度特性を変化させ、特定の波長帯域の光のみを被写体に照射することにより、生体内の被写体のうち、特定の組織を強調した撮影画像を得ることができる。 In the light source device described in Patent Document 1, when the optical filter is removed from the optical path, the light emitted from the phosphor LED is irradiated to the subject as white light without limiting the wavelength band. . On the other hand, when the optical filter is inserted on the optical path, the subject is irradiated with both the irradiation light emitted from the phosphor LED and the wavelength band limited and the irradiation light emitted from the purple LED. Thus, by changing the spectral intensity characteristic of the irradiation light and irradiating the subject with only light in a specific wavelength band, it is possible to obtain a captured image in which a specific tissue is emphasized among subjects in the living body.
　特許文献１に記載の光源装置では、特定の波長帯域にのみ高い強度を有する照射光を得るために、光学フィルタによって白色ＬＥＤから射出される照射光の波長帯域を制限し、不要な波長帯域の光をカットしている。このカットされた光は被写体には照射されないため、光源装置の光利用効率が低いという問題がある。 In the light source device described in Patent Document 1, in order to obtain irradiation light having high intensity only in a specific wavelength band, the wavelength band of irradiation light emitted from the white LED is limited by an optical filter, and an unnecessary wavelength band is obtained. The light is cut. Since the cut light is not irradiated to the subject, there is a problem that the light use efficiency of the light source device is low.
　本発明は上記の事情に鑑みてなされたものであり、その目的とするところは、特定の波長帯域にのみ高い強度を有する照射光を高い光利用効率で照射することが可能な内視鏡用光源装置及び内視鏡システムを提供することである。 The present invention has been made in view of the above circumstances, and an object of the present invention is for an endoscope capable of irradiating irradiation light having high intensity only in a specific wavelength band with high light utilization efficiency. A light source device and an endoscope system are provided.
　本発明の一実施形態に係る内視鏡用光源装置は、第１の波長帯域の光を射出する第１の固体発光素子と、第１の波長帯域の光によって励起され、第１の蛍光を発する第１の蛍光体と、を有する第１の光源ユニットと、第１の蛍光体を第１の固体発光素子から射出される光の光路に対して挿抜可能に支持する蛍光体挿抜手段と、を備える。この構成において、蛍光体挿抜手段により第１の蛍光体が第１の固体発光素子から射出される光の光路に挿入されると、第１の光源ユニットから第１の波長帯域の光と第１の蛍光とが同一の光路で射出されて内視鏡に供給される。また、蛍光体挿抜手段により第１の蛍光体が第１の固体発光素子から射出される光の光路から抜去されると、第１の光源ユニットから第１の波長帯域の光が射出されて内視鏡に供給される。 An endoscope light source device according to an embodiment of the present invention is excited by a first solid-state light emitting element that emits light of a first wavelength band and light of a first wavelength band, and emits first fluorescence. A first light source unit having a first phosphor that emits, and a phosphor insertion / extraction means that supports the first phosphor so as to be insertable / removable with respect to an optical path of light emitted from the first solid-state light emitting element, Is provided. In this configuration, when the first phosphor is inserted into the optical path of the light emitted from the first solid state light emitting device by the phosphor inserting / extracting means, the first wavelength band of light and the first wavelength band are transmitted from the first light source unit. Are emitted in the same optical path and supplied to the endoscope. Further, when the first phosphor is removed from the optical path of the light emitted from the first solid state light emitting device by the phosphor insertion / extraction means, the light of the first wavelength band is emitted from the first light source unit. Supplied to the endoscope.
　このような構成によれば、蛍光体を、固体発光素子から射出される光の光路に挿入することにより、可視光領域内に広い波長帯域を有する通常光を被写体に照射することができる。また、蛍光体を光路から抜去することにより、被写体の特定の生体組織に対する吸光度の高い波長帯域の光の強度が、他の波長帯域に比べて高い特殊光を被写体に照射することができる。また、照射光の分光強度特性の切り替えを行う際に、波長制限フィルタ等の光学フィルタを用いる必要が無いため、分光強度特性の切り替えに伴う光量損失を抑えることができる。 According to such a configuration, the subject can be irradiated with normal light having a wide wavelength band in the visible light region by inserting the phosphor into the optical path of the light emitted from the solid state light emitting device. Further, by removing the phosphor from the optical path, it is possible to irradiate the subject with special light whose intensity of light in a wavelength band having high absorbance with respect to a specific biological tissue of the subject is higher than in other wavelength bands. In addition, since it is not necessary to use an optical filter such as a wavelength limiting filter when switching the spectral intensity characteristics of the irradiation light, it is possible to suppress light amount loss due to switching of the spectral intensity characteristics.
　また、本発明の一実施形態において、内視鏡用光源装置は、例えば、第１の蛍光の波長帯域のピーク波長とは異なるピーク波長をもつ波長帯域の光を射出する第２の光源ユニットと、第１の光源ユニットから射出される光の光路と第２の光源ユニットから射出される光の光路とを合成し、光路を合成した光を内視鏡に供給する第１の光路合成手段と、を更に備える。 In one embodiment of the present invention, the endoscope light source device includes, for example, a second light source unit that emits light in a wavelength band having a peak wavelength different from the peak wavelength of the first fluorescence wavelength band; First optical path synthesis means for synthesizing the optical path of the light emitted from the first light source unit and the optical path of the light emitted from the second light source unit, and supplying the combined light to the endoscope Are further provided.
　また、本発明の一実施形態において、第２の光源ユニットは、例えば、第２の固体発光素子と、第２の固体発光素子から射出された光によって励起され、第２の蛍光を発する第２の蛍光体と、を有する。この構成において、第２の蛍光の波長帯域のピーク波長は、第１の波長帯域のピーク波長及び第１の蛍光の波長帯域のピーク波長とは異なる。 In one embodiment of the present invention, for example, the second light source unit is excited by the second solid light emitting element and the light emitted from the second solid light emitting element, and emits second fluorescence. And a phosphor. In this configuration, the peak wavelength of the second fluorescence wavelength band is different from the peak wavelength of the first wavelength band and the peak wavelength of the first fluorescence wavelength band.
　また、本発明の一実施形態において、内視鏡用光源装置は、例えば、第１の光源ユニットから射出される光のピーク波長及び第２の光源ユニットから射出される光のピーク波長とは異なるピーク波長をもつ第３の波長帯域の光を射出する第３の光源ユニットと、第１の光路合成手段によって合成された光の光路と、第３の光源ユニットから射出された光の光路とを合成し、光路を合成した光を内視鏡に供給する第２の光路合成手段と、を更に備える。 In one embodiment of the present invention, the endoscope light source device is different from the peak wavelength of light emitted from the first light source unit and the peak wavelength of light emitted from the second light source unit, for example. A third light source unit that emits light in a third wavelength band having a peak wavelength, an optical path of light synthesized by the first optical path synthesis unit, and an optical path of light emitted from the third light source unit A second optical path synthesizing unit that synthesizes and supplies the combined optical path to the endoscope.
　また、本発明の一実施形態において、第１の光源ユニットは、例えば、第１の固体発光素子から射出された第１の波長帯域の光によって励起され、第１の蛍光のピーク波長とは異なるピーク波長をもつ第３の蛍光を発する第３の蛍光体を更に有する。この場合、蛍光体挿抜手段により第１の蛍光体が第１の固体発光素子から射出される光の光路に挿入されると、第１の光源ユニットから第１の波長帯域の光、第１の蛍光、第３の蛍光が同一の光路で射出されて内視鏡に供給される。また、蛍光体挿抜手段により第１の蛍光体が第１の固体発光素子から射出される光の光路から抜去されると、第１の光源ユニットから第１の波長帯域及び第３の蛍光が同一の光路で射出されて内視鏡に供給される。 In one embodiment of the present invention, the first light source unit is excited by, for example, light in the first wavelength band emitted from the first solid state light emitting device, and is different from the peak wavelength of the first fluorescence. A third phosphor that emits third fluorescence having a peak wavelength is further included. In this case, when the first phosphor is inserted into the optical path of the light emitted from the first solid-state light emitting element by the phosphor insertion / extraction means, the light in the first wavelength band from the first light source unit, the first Fluorescence and third fluorescence are emitted along the same optical path and supplied to the endoscope. Further, when the first phosphor is removed from the optical path of the light emitted from the first solid state light emitting device by the phosphor insertion / extraction means, the first wavelength band and the third fluorescence are the same from the first light source unit. And are supplied to the endoscope.
　また、本発明の一実施形態において、第１の光源ユニットは、例えば、第１の固体発光素子から射出された第１の波長帯域の光によって励起され、第１の蛍光のピーク波長及び第３の蛍光のピーク波長とは異なるピーク波長をもつ第４の蛍光を発する第４の蛍光体を更に備える。この場合、蛍光体挿抜手段は、第１の蛍光体及び第４の蛍光体を、第１の固体発光素子から射出される光の光路に対して個別に挿抜可能に支持する。 In one embodiment of the present invention, the first light source unit is excited by, for example, light in the first wavelength band emitted from the first solid-state light emitting element, and the first fluorescence peak wavelength and the third wavelength. And a fourth phosphor that emits a fourth fluorescence having a peak wavelength different from the peak wavelength of the fluorescence. In this case, the phosphor insertion / extraction means supports the first phosphor and the fourth phosphor so that they can be individually inserted into and removed from the optical path of the light emitted from the first solid state light emitting device.
　また、本発明の一実施形態に係る内視鏡用光源装置は、所定の撮像周期と同期して回転するターレットを更に備える構成としてもよい。この場合、ターレットには、夫々異なる発光特性を持つ蛍光体が周方向に並べて配置されている。ターレットが回転することによって照射光の光路に各蛍光体が順に挿入されると、該照射光が、順次、該光路上に挿入された蛍光体に応じた光となって内視鏡に供給される。 The endoscope light source device according to an embodiment of the present invention may further include a turret that rotates in synchronization with a predetermined imaging cycle. In this case, phosphors having different light emission characteristics are arranged in the circumferential direction on the turret. When each phosphor is sequentially inserted into the optical path of the irradiation light by rotating the turret, the irradiation light is sequentially supplied to the endoscope as light corresponding to the phosphor inserted on the optical path. The
　また、本発明に一実施形態に係る内視鏡システムは、上記の内視鏡用光源装置と内視鏡とを備える。 In addition, an endoscope system according to an embodiment of the present invention includes the above-described endoscope light source device and an endoscope.
　本発明の一実施形態によれば、特定の波長帯域にのみ高い強度を有する照射光を高い光利用効率で照射することが可能な内視鏡用光源装置及び内視鏡システムが提供される。 According to an embodiment of the present invention, an endoscope light source device and an endoscope system capable of irradiating irradiation light having high intensity only in a specific wavelength band with high light utilization efficiency are provided.
本発明の第１の実施形態に係る電子内視鏡システムの構成を示すブロック図である。1 is a block diagram illustrating a configuration of an electronic endoscope system according to a first embodiment of the present invention. 本発明の第１の実施形態に係る内視鏡用光源装置のブロック図である。It is a block diagram of the light source device for endoscopes concerning a 1st embodiment of the present invention. 本発明の第１の実施形態に係る内視鏡用光源装置のブロック図である。It is a block diagram of the light source device for endoscopes concerning a 1st embodiment of the present invention. 本発明の第１の実施形態に係る内視鏡用光源装置から射出される照射光の分光強度分布を示す図である。It is a figure which shows the spectral intensity distribution of the irradiation light inject | emitted from the light source device for endoscopes which concerns on the 1st Embodiment of this invention. 本発明の第２の実施形態に係る内視鏡用光源装置のブロック図である。It is a block diagram of the light source device for endoscopes which concerns on the 2nd Embodiment of this invention. 本発明の第２の実施形態に係る内視鏡用光源装置から射出される照射光の分光強度分布を示す図である。It is a figure which shows the spectral intensity distribution of the irradiated light inject | emitted from the light source device for endoscopes which concerns on the 2nd Embodiment of this invention. 本発明の第３の実施形態に係る内視鏡用光源装置のブロック図である。It is a block diagram of the light source device for endoscopes which concerns on the 3rd Embodiment of this invention. 本発明の第３の実施形態に係る内視鏡用光源装置から射出される照射光の分光強度分布を示す図である。It is a figure which shows the spectral intensity distribution of the irradiation light inject | emitted from the light source device for endoscopes which concerns on the 3rd Embodiment of this invention. 本発明の第４の実施形態に係る内視鏡用光源装置のブロック図である。It is a block diagram of the light source device for endoscopes which concerns on the 4th Embodiment of this invention. 本発明の第４の実施形態に係る内視鏡用光源装置から射出される照射光の分光強度分布を示す図である。It is a figure which shows the spectral intensity distribution of the irradiated light inject | emitted from the light source device for endoscopes which concerns on the 4th Embodiment of this invention. 本発明の第５の実施形態に係る内視鏡用光源装置のブロック図である。It is a block diagram of the light source device for endoscopes which concerns on the 5th Embodiment of this invention. 本発明の第５の実施形態に係る内視鏡用光源装置から射出される照射光の分光強度分布を示す図である。It is a figure which shows the spectral intensity distribution of the irradiated light inject | emitted from the light source device for endoscopes which concerns on the 5th Embodiment of this invention. 本発明の第６の実施形態に係る内視鏡用光源装置のブロック図である。It is a block diagram of the light source device for endoscopes which concerns on the 6th Embodiment of this invention. 本発明の第６の実施形態に係る内視鏡用光源装置から射出される照射光の分光強度分布を示す図である。It is a figure which shows the spectral intensity distribution of the irradiated light inject | emitted from the light source device for endoscopes which concerns on the 6th Embodiment of this invention. 本発明の第７の実施形態に係る内視鏡用光源装置のブロック図である。It is a block diagram of the light source device for endoscopes which concerns on the 7th Embodiment of this invention. 本発明の第７の実施形態に係る内視鏡用光源装置から射出される照射光の分光強度分布を示す図である。It is a figure which shows the spectral intensity distribution of the irradiated light inject | emitted from the light source device for endoscopes which concerns on the 7th Embodiment of this invention. 本発明の第４の実施形態の変形例に係る内視鏡用光源装置から射出される照射光の分光強度分布を示す図である。It is a figure which shows the spectral intensity distribution of the irradiated light inject | emitted from the light source device for endoscopes which concerns on the modification of the 4th Embodiment of this invention. 本発明の別の実施形態に係る内視鏡用光源装置のブロック図である。It is a block diagram of the light source device for endoscopes concerning another embodiment of the present invention. 本発明の別の実施形態に係る内視鏡用光源装置のブロック図である。It is a block diagram of the light source device for endoscopes concerning another embodiment of the present invention. 本発明の別の実施形態に係る内視鏡用光源装置に備えられる回転式ターレットの構成を示す図である。It is a figure which shows the structure of the rotary turret with which the light source device for endoscopes concerning another embodiment of this invention is equipped. ５５０ｎｍ付近を拡大したヘモグロビンの吸収スペクトルである。It is an absorption spectrum of hemoglobin in which the vicinity of 550 nm is enlarged.
　以下、本発明の実施形態について図面を参照しながら説明する。なお、以下においては、本発明の一実施形態として内視鏡用光源装置を備える電子内視鏡システムを例に取り説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, an electronic endoscope system including an endoscope light source device will be described as an embodiment of the present invention.
（第１の実施形態）
　図１は、本発明の第１の実施形態に係る内視鏡用光源装置２０１を備えた電子内視鏡システム１の構成を示すブロック図である。図１に示されるように、電子内視鏡システム１は、医療用に特化されたシステムであり、電子スコープ１００、プロセッサ２００及びモニタ３００を備えている。 (First embodiment)
FIG. 1 is a block diagram showing a configuration of an electronic endoscope system 1 including an endoscope light source device 201 according to the first embodiment of the present invention. As shown in FIG. 1, the electronic endoscope system 1 is a system specialized for medical use, and includes an electronic scope 100, a processor 200, and a monitor 300.
　プロセッサ２００は、システムコントローラ２１及びタイミングコントローラ２２を備えている。システムコントローラ２１は、メモリ２３に記憶された各種プログラムを実行し、電子内視鏡システム１全体を統合的に制御する。また、システムコントローラ２１は、操作パネル２４に接続されている。システムコントローラ２１は、操作パネル２４に入力される術者からの指示に応じて、電子内視鏡システム１の各動作及び各動作のためのパラメータを変更する。術者による入力指示には、例えば電子内視鏡システム１の観察モードの切替指示がある。観察モードには、通常観察モード、特殊観察モードがある。各観察モードについての詳細は後述する。タイミングコントローラ２２は、各部の動作のタイミングを調整するクロックパルスを電子内視鏡システム１内の各回路に出力する。 The processor 200 includes a system controller 21 and a timing controller 22. The system controller 21 executes various programs stored in the memory 23 and controls the entire electronic endoscope system 1 in an integrated manner. The system controller 21 is connected to the operation panel 24. The system controller 21 changes each operation of the electronic endoscope system 1 and parameters for each operation in accordance with an instruction from the operator input to the operation panel 24. The input instruction by the operator includes, for example, an instruction to switch the observation mode of the electronic endoscope system 1. The observation mode includes a normal observation mode and a special observation mode. Details of each observation mode will be described later. The timing controller 22 outputs a clock pulse for adjusting the operation timing of each unit to each circuit in the electronic endoscope system 1.
　プロセッサ２００は、光源装置２０１を備えている。図２に、本発明の第１の実施形態に係る光源装置２０１のブロック図を示す。光源装置２０１は、第１の光源ユニット１１１及び第２の光源ユニット１１２を備えている。第１、第２の光源ユニット１１１、１１２はそれぞれ、第１、第２光源駆動回路１４１、１４２によって個別に発光制御される。 The processor 200 includes a light source device 201. FIG. 2 is a block diagram of the light source device 201 according to the first embodiment of the present invention. The light source device 201 includes a first light source unit 111 and a second light source unit 112. The first and second light source units 111 and 112 are individually controlled to emit light by the first and second light source drive circuits 141 and 142, respectively.
　本実施形態では、光源装置２０１がプロセッサ２００内に備えられているが、別の実施形態では、光源装置２０１は、プロセッサ２００（より正確には、画像処理装置を構成する部分）と別体の装置であってもよい。 In this embodiment, the light source device 201 is provided in the processor 200. However, in another embodiment, the light source device 201 is separate from the processor 200 (more precisely, a part constituting the image processing device). It may be a device.
　第１の光源ユニット１１１は、紫色の波長帯域（例えば、波長が３９５～４３５ｎｍ）の光を射出する紫色発光ダイオード（ＬＥＤ：Light Emitting Diode）１１１ａと、青色蛍光体１１１ｂとを有している。青色蛍光体１１１ｂは、紫色ＬＥＤ１１１ａから射出された紫色ＬＥＤ光によって励起され、青色の波長帯域（例えば、波長４３０～５５０ｎｍ）の蛍光を発する。 The first light source unit 111 includes a purple light emitting diode (LED: Light Emitting Diode) 111a that emits light in a purple wavelength band (for example, a wavelength of 395 to 435 nm) and a blue phosphor 111b. The blue phosphor 111b is excited by the purple LED light emitted from the purple LED 111a and emits fluorescence in a blue wavelength band (for example, a wavelength of 430 to 550 nm).
　青色蛍光体１１１ｂは、蛍光体挿抜機構１５１により、光路上に挿抜可能に支持されている。詳しくは、青色蛍光体１１１ｂは、観察モードに応じて、紫色ＬＥＤ１１１ａから射出された紫色ＬＥＤ光の光路に挿入又は抜去される。図２に実線で示すように、青色蛍光体１１１ｂが紫色ＬＥＤ光の光路上に挿入されている場合、青色蛍光体１１１ｂは青色の蛍光を発する。これにより、光源ユニット１１１からは、紫色ＬＥＤ光と青色の蛍光の両方が射出される。また、図２に点線で示すように、青色蛍光体１１１ｂが紫色ＬＥＤ光の光路から抜去されている場合、青色蛍光体１１１ｂは励起されず、蛍光を発しない。そのため、光源ユニット１１１からは、紫色ＬＥＤ光のみが射出される。 The blue phosphor 111b is supported by the phosphor insertion / extraction mechanism 151 so that it can be inserted into and removed from the optical path. Specifically, the blue phosphor 111b is inserted into or removed from the optical path of the purple LED light emitted from the purple LED 111a according to the observation mode. As shown by a solid line in FIG. 2, when the blue phosphor 111b is inserted on the optical path of the purple LED light, the blue phosphor 111b emits blue fluorescence. Thereby, both the purple LED light and the blue fluorescence are emitted from the light source unit 111. Further, as shown by the dotted line in FIG. 2, when the blue phosphor 111b is removed from the optical path of the purple LED light, the blue phosphor 111b is not excited and does not emit fluorescence. Therefore, only the purple LED light is emitted from the light source unit 111.
　第２の光源ユニット１１２は、青色の波長帯域（例えば、波長が４２０～４８０ｎｍ）の光を射出する青色ＬＥＤ１１２ａと、黄色蛍光体１１２ｂとを有している。黄色蛍光体１１２ｂは、青色ＬＥＤ１１２ａから射出された青色ＬＥＤ光によって励起され、黄色の波長帯域（例えば、波長が４２０～７００ｎｍ）の蛍光を発する。黄色蛍光体１１２ｂは青色ＬＥＤ１１２ａの発光面上に取り付けられており、青色蛍光体１１１ｂとは異なり、青色ＬＥＤ光の光路上に挿抜可能ではない。 The second light source unit 112 includes a blue LED 112a that emits light in a blue wavelength band (for example, a wavelength of 420 to 480 nm), and a yellow phosphor 112b. The yellow phosphor 112b is excited by the blue LED light emitted from the blue LED 112a, and emits fluorescence in a yellow wavelength band (for example, a wavelength is 420 to 700 nm). The yellow phosphor 112b is attached on the light emitting surface of the blue LED 112a, and unlike the blue phosphor 111b, it cannot be inserted into and removed from the optical path of the blue LED light.
　各光源ユニット１１１、１１２の光の射出方向の前方にはそれぞれ、コリメートレンズ１２１、１２２が配置されている。第１の光源ユニット１１１から射出された光は、コリメートレンズ１２１によって平行光に変換され、ダイクロイックミラー１３１に入射される。また、第２の光源ユニット１１２から射出された光は、コリメートレンズ１２２によって平行光に変換され、ダイクロイックミラー１３１に入射される。ダイクロイックミラー１３１は、第１の光源ユニット１１１から射出された光の光路と、第２の光源ユニット１１２から射出された光の光路とを合成する。詳しくは、ダイクロイックミラー１３１は、波長５２０ｎｍ付近にカットオフ波長を有しており、カットオフ波長よりも短い波長の光を透過させ、カットオフ波長以上の波長の光を反射する特性を有している。そのため、第１の光源ユニット１１１から射出された紫色ＬＥＤ光や青色の蛍光はダイクロイックミラー１３１を透過する。また、第２の光源ユニット１１２から射出された黄色の蛍光はダイクロイックミラー１３１で反射される。これにより、第１の光源ユニット１１１から射出された光と第２の光源ユニット１１２から射出された光の光路が合成される。ダイクロイックミラー１３１によって光路が合成された光は、光源装置２０１から照射光Ｌとして射出される。 Collimating lenses 121 and 122 are arranged in front of the light source units 111 and 112 in the light emission direction, respectively. The light emitted from the first light source unit 111 is converted into parallel light by the collimator lens 121 and is incident on the dichroic mirror 131. The light emitted from the second light source unit 112 is converted into parallel light by the collimator lens 122 and is incident on the dichroic mirror 131. The dichroic mirror 131 combines the optical path of the light emitted from the first light source unit 111 and the optical path of the light emitted from the second light source unit 112. Specifically, the dichroic mirror 131 has a cutoff wavelength in the vicinity of a wavelength of 520 nm, transmits light having a wavelength shorter than the cutoff wavelength, and reflects light having a wavelength longer than the cutoff wavelength. Yes. Therefore, the purple LED light and the blue fluorescence emitted from the first light source unit 111 are transmitted through the dichroic mirror 131. Further, the yellow fluorescence emitted from the second light source unit 112 is reflected by the dichroic mirror 131. Thereby, the optical path of the light emitted from the first light source unit 111 and the light emitted from the second light source unit 112 is combined. The light whose optical path is synthesized by the dichroic mirror 131 is emitted from the light source device 201 as the irradiation light L.
　図３は、光源装置２０１のうち、各光源ユニット１１１、１１２及びダイクロイックミラー１３１のみを概念的に示したブロック図である。青色蛍光体１１１ｂは、紫色ＬＥＤ１１１ａとは別体であるため、図３において、青色蛍光体１１１ｂと紫色ＬＥＤ１１１ａは、別々のブロックで示されている。一方、黄色蛍光体１１２ｂは、青色ＬＥＤ１１２ａの発光面に取り付けられており、青色ＬＥＤ１１２ａと一体に構成されているため、図３において、黄色蛍光体１１２ｂと青色ＬＥＤ１１２ａは、一つのブロックで示されている。 FIG. 3 is a block diagram conceptually showing only the light source units 111 and 112 and the dichroic mirror 131 in the light source device 201. Since the blue phosphor 111b is separate from the purple LED 111a, the blue phosphor 111b and the purple LED 111a are shown in separate blocks in FIG. On the other hand, since the yellow phosphor 112b is attached to the light emitting surface of the blue LED 112a and is integrally formed with the blue LED 112a, the yellow phosphor 112b and the blue LED 112a are shown as one block in FIG. Yes.
　また、ダイクロイックミラー１３１は、波長の異なる光の光路を合成するものである。そのため、図３において、ダイクロイックミラー１３１は、加算記号「＋」で示されている。また、図３において、各光源ユニット１１１、１１２の前方に配置されたコリメートレンズ１２１、１２２は省略されている。 Further, the dichroic mirror 131 synthesizes optical paths of light having different wavelengths. Therefore, in FIG. 3, the dichroic mirror 131 is indicated by an addition symbol “+”. In FIG. 3, the collimating lenses 121 and 122 arranged in front of the light source units 111 and 112 are omitted.
　図３において、各矢印は光の光路を示している。図３に示す例では、第１の光源ユニット１１１の紫色ＬＥＤ１１１ａから射出された紫色ＬＥＤ光と、青色蛍光体１１１ｂが発した青色の蛍光が同一の光路で射出される。また、第２の光源ユニット１１２の青色ＬＥＤから射出された青色ＬＥＤ光と、黄色蛍光体が発した黄色の蛍光が同一の光路で射出される。第１の光源ユニットから射出された光の光路と第２の光源ユニットから射出された光の光路は、ダイクロイックミラー１３１で合成される。ダイクロイックミラー１３１で光路が合成された光は、光源装置２０１から、照射光Ｌとして射出される。 In FIG. 3, each arrow indicates an optical path of light. In the example shown in FIG. 3, the purple LED light emitted from the purple LED 111a of the first light source unit 111 and the blue fluorescence emitted from the blue phosphor 111b are emitted in the same optical path. Further, the blue LED light emitted from the blue LED of the second light source unit 112 and the yellow fluorescence emitted from the yellow phosphor are emitted in the same optical path. The optical path of the light emitted from the first light source unit and the optical path of the light emitted from the second light source unit are combined by the dichroic mirror 131. The light whose optical path is synthesized by the dichroic mirror 131 is emitted as the irradiation light L from the light source device 201.
　図１に示すように、光源装置２０１から射出された照射光Ｌは、集光レンズ２５によりＬＣＢ（Light Carrying Bundle）１１の入射端面に集光されてＬＣＢ１１内に入射される。 As shown in FIG. 1, the irradiation light L emitted from the light source device 201 is condensed on the incident end face of the LCB (Light Carrying Bundle) 11 by the condenser lens 25 and enters the LCB 11.
　ＬＣＢ１１内に入射された照射光Ｌは、ＬＣＢ１１内を伝播する。ＬＣＢ１１内を伝播した照射光Ｌは、電子スコープ１００の先端に配置されたＬＣＢ１１の射出端面から射出され、配光レンズ１２を介して被写体に照射される。配光レンズ１２からの照射光Ｌによって照射された被写体からの戻り光は、対物レンズ１３を介して固体撮像素子１４の受光面上で光学像を結ぶ。 The irradiation light L incident on the LCB 11 propagates in the LCB 11. The irradiation light L propagating through the LCB 11 is emitted from the emission end surface of the LCB 11 disposed at the tip of the electronic scope 100 and is irradiated onto the subject via the light distribution lens 12. The return light from the subject irradiated with the irradiation light L from the light distribution lens 12 forms an optical image on the light receiving surface of the solid-state imaging device 14 via the objective lens 13.
　固体撮像素子１４は、ベイヤ型画素配置を有する単板式カラーＣＣＤ（Charge Coupled Device）イメージセンサである。固体撮像素子１４は、受光面上の各画素で結像した光学像を光量に応じた電荷として蓄積して、Ｒ（Red）、Ｇ（Green）、Ｂ（Blue）の画像信号を生成して出力する。なお、固体撮像素子１４は、ＣＣＤイメージセンサに限らず、ＣＭＯＳ（Complementary Metal Oxide Semiconductor）イメージセンサやその他の種類の撮像装置に置き換えられてもよい。固体撮像素子１４はまた、補色系フィルタを搭載したものであってもよい。 The solid-state imaging device 14 is a single-plate color CCD (Charge Coupled Device) image sensor having a Bayer pixel arrangement. The solid-state imaging device 14 accumulates an optical image formed by each pixel on the light receiving surface as a charge corresponding to the amount of light, and generates R (Red), G (Green), and B (Blue) image signals. Output. The solid-state imaging device 14 is not limited to a CCD image sensor, and may be replaced with a CMOS (Complementary Metal Oxide Semiconductor) image sensor or other types of imaging devices. The solid-state image sensor 14 may also be one having a complementary color filter mounted thereon.
　電子スコープ１００の接続部内には、ドライバ信号処理回路１５が備えられている。ドライバ信号処理回路１５には、配光レンズ１２からの光によって照射された被写体の画像信号がフレーム周期で固体撮像素子１４から入力される。フレーム周期は、例えば、１／３０秒である。ドライバ信号処理回路１５は、固体撮像素子１４から入力される画像信号に対して所定の処理を施してプロセッサ２００の前段信号処理回路２６に出力する。 In the connection part of the electronic scope 100, a driver signal processing circuit 15 is provided. An image signal of a subject irradiated with light from the light distribution lens 12 is input to the driver signal processing circuit 15 from the solid-state imaging device 14 at a frame period. The frame period is, for example, 1/30 seconds. The driver signal processing circuit 15 performs a predetermined process on the image signal input from the solid-state imaging device 14 and outputs the processed image signal to the upstream signal processing circuit 26 of the processor 200.
　ドライバ信号処理回路１５はまた、メモリ１６にアクセスして電子スコープ１００の固有情報を読み出す。メモリ１６に記録される電子スコープ１００の固有情報には、例えば、固体撮像素子１４の画素数や感度、動作可能なフレームレート、型番等が含まれる。ドライバ信号処理回路１５は、メモリ１６から読み出された固有情報をシステムコントローラ２１に出力する。 The driver signal processing circuit 15 also accesses the memory 16 and reads the unique information of the electronic scope 100. The unique information of the electronic scope 100 recorded in the memory 16 includes, for example, the number and sensitivity of the solid-state imaging device 14, an operable frame rate, a model number, and the like. The driver signal processing circuit 15 outputs the unique information read from the memory 16 to the system controller 21.
　システムコントローラ２１は、電子スコープ１００の固有情報に基づいて各種演算を行い、制御信号を生成する。システムコントローラ２１は、生成された制御信号を用いて、プロセッサ２００に接続されている電子スコープ１００に適した処理がなされるようにプロセッサ２００内の各種回路の動作やタイミングを制御する。 The system controller 21 performs various calculations based on the unique information of the electronic scope 100 and generates a control signal. The system controller 21 uses the generated control signal to control the operation and timing of various circuits in the processor 200 so that processing suitable for the electronic scope 100 connected to the processor 200 is performed.
　タイミングコントローラ２２は、システムコントローラ２１によるタイミング制御に従って、ドライバ信号処理回路１５にクロックパルスを供給する。ドライバ信号処理回路１５は、タイミングコントローラ２２から供給されるクロックパルスに従って、固体撮像素子１４をプロセッサ２００側で処理される映像のフレームレートに同期したタイミングで駆動制御する。 The timing controller 22 supplies clock pulses to the driver signal processing circuit 15 according to the timing control by the system controller 21. The driver signal processing circuit 15 drives and controls the solid-state imaging device 14 at a timing synchronized with the frame rate of the video processed on the processor 200 side in accordance with the clock pulse supplied from the timing controller 22.
　前段信号処理回路２６は、ドライバ信号処理回路１５から１フレーム周期で入力される画像信号に対してデモザイク処理、マトリックス演算、Ｙ／Ｃ分離等の所定の信号処理を施して、画像メモリ２７に出力する。 The pre-stage signal processing circuit 26 performs predetermined signal processing such as demosaic processing, matrix calculation, and Y / C separation on the image signal input from the driver signal processing circuit 15 in one frame period, and outputs it to the image memory 27. To do.
　画像メモリ２７は、前段信号処理回路２６から入力される画像信号をバッファし、タイミングコントローラ２２によるタイミング制御に従い、後段信号処理回路２８に出力する。 The image memory 27 buffers the image signal input from the upstream signal processing circuit 26 and outputs it to the downstream signal processing circuit 28 according to the timing control by the timing controller 22.
　後段信号処理回路２８は、画像メモリ２７から入力される画像信号を処理してモニタ表示用の画面データを生成し、生成されたモニタ表示用の画面データを所定のビデオフォーマット信号に変換する。変換されたビデオフォーマット信号は、モニタ３００に出力される。これにより、被写体の画像がモニタ３００の表示画面に表示される。 The post-stage signal processing circuit 28 processes the image signal input from the image memory 27 to generate screen data for monitor display, and converts the generated screen data for monitor display into a predetermined video format signal. The converted video format signal is output to the monitor 300. Thereby, the image of the subject is displayed on the display screen of the monitor 300.
　本実施形態の電子内視鏡システム１は、通常観察モードと特殊観察モードを含む複数の観察モードを有している。各観察モードは、観察する被写体によって手動又は自動で切り替えられる。例えば、被写体を通常光で照明して観察したい場合は、観察モードが通常観察モードに切り替えられる。なお、通常光は、例えば、白色光や擬似白色光である。白色光は可視光帯域においてフラットな分光強度分布を有する。擬似白色光は、分光強度分布はフラットではなく、複数の波長帯域の光が混色されている。また、例えば、被写体を特殊光で照明することによって特定の生体組織が強調された撮影画像を得たい場合は、観察モードが特殊観察モードに切り替えられる。 The electronic endoscope system 1 of the present embodiment has a plurality of observation modes including a normal observation mode and a special observation mode. Each observation mode is switched manually or automatically depending on the subject to be observed. For example, when it is desired to observe the subject illuminated with normal light, the observation mode is switched to the normal observation mode. The normal light is, for example, white light or pseudo white light. White light has a flat spectral intensity distribution in the visible light band. The pseudo-white light has a spectral intensity distribution that is not flat, and light in a plurality of wavelength bands is mixed. For example, when it is desired to obtain a captured image in which a specific living tissue is emphasized by illuminating the subject with special light, the observation mode is switched to the special observation mode.
　なお、特殊光は、例えば、鮮鋭なピークを特定波長に持つ狭帯域光であって、特定の生体組織に対して吸光度の高い光である。特定波長の光には、例えば、表層血管に対して吸光度の高い４１５ｎｍ付近（例えば４１５±５ｎｍ）の光、表層よりも深い中層の血管に対して吸光度の高い５５０ｎｍ付近（例えば５５０±５ｎｍ）の光、中層よりも深い深層の血管に対して吸光度の高い６５０ｎｍ付近（例えば６５０±５ｎｍ）の光が挙げられる。なお、波長の長い光ほど生体組織への深達度が深くなる。そのため、４１５ｎｍ付近、５５０ｎｍ付近、６５０ｎｍ付近の狭帯域光の順に、深達する層域が深くなっている。以下では、特殊観察モードで強調される生体組織が、表層血管である場合について主に説明する。 Note that the special light is, for example, narrow band light having a sharp peak at a specific wavelength, and light having high absorbance with respect to a specific living tissue. For light of a specific wavelength, for example, light having a high absorbance of 415 nm (for example, 415 ± 5 nm) with respect to the surface blood vessel, and light having a high absorbance of 550 nm (for example, 550 ± 5 nm) for the blood vessel in the middle layer deeper than the surface layer. Light and light in the vicinity of 650 nm (for example, 650 ± 5 nm) having a high absorbance with respect to deep blood vessels deeper than the middle layer can be mentioned. Note that the longer the wavelength, the deeper the depth of penetration into the living tissue. For this reason, the layer region that reaches deeper becomes deeper in the order of narrowband light near 415 nm, 550 nm, and 650 nm. Hereinafter, a case where the biological tissue emphasized in the special observation mode is a surface blood vessel will be mainly described.
　表層血管内にはヘモグロビンを含む血液が流れている。ヘモグロビンは、波長４１５ｎｍ付近と５５０ｎｍ付近に吸光度のピークを有することが知られている。そのため、被写体に対して表層血管を強調するのに適した特殊光（具体的には、他の波長帯域よりもヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の強度が高い光）を照射することにより、表層血管が強調された撮影画像を得ることができる。波長５５０ｎｍ付近の強度が高い特殊光は、表層血管に対しても比較的高い吸光度を持っている。言い換えると、波長５５０ｎｍ付近の強度が高い特殊光も表層血管の強調表示に寄与する。そのため、波長４１５ｎｍ付近の光と共に、ヘモグロビンの吸光度のもう一つのピークとなる波長５５０ｎｍ付近の強度が高い特殊光を照射することにより、表層血管が強調された状態を維持しつつ、撮影画像の輝度を明るくすることができる。 血液 Blood containing hemoglobin flows in the surface blood vessels. It is known that hemoglobin has absorbance peaks near wavelengths of 415 nm and 550 nm. Therefore, by irradiating the subject with special light suitable for emphasizing the superficial blood vessels (specifically, light having a higher intensity near the wavelength of 415 nm where the absorbance of hemoglobin is peak than other wavelength bands). A captured image in which the superficial blood vessels are emphasized can be obtained. Special light having a high intensity near the wavelength of 550 nm has a relatively high absorbance even for the surface blood vessels. In other words, special light having a high intensity in the vicinity of a wavelength of 550 nm also contributes to highlighting of the surface blood vessels. Therefore, by irradiating special light having a high intensity near the wavelength of 550 nm, which is another peak of the absorbance of hemoglobin, together with light near the wavelength of 415 nm, the brightness of the photographed image is maintained while maintaining the state where the surface blood vessels are emphasized. Can be brightened.
　すなわち、特殊観察モードでは、特定波長にピークを持つ狭帯域光（特殊光）を用いることにより、通常観察モードでは観察することが難しい血管（表層や中層、深層等の各層域の血管）の走行状態を明瞭に把握するのに適した狭帯域観察を行うことができる。狭帯域観察を行うことにより、癌等の病変の早期発見に有用な情報が得られる。 That is, in special observation mode, by using narrowband light (special light) having a peak at a specific wavelength, blood vessels that are difficult to observe in normal observation mode (blood vessels in each layer such as the surface layer, middle layer, and deep layer) travel. Narrow band observation suitable for clearly grasping the state can be performed. By performing narrow band observation, information useful for early detection of lesions such as cancer can be obtained.
　図４は、各観察モードにおいて、光源装置２０１から射出される照射光Ｌの分光強度分布を示している。図４（ａ）は、通常観察モードにおける照射光Ｌ（通常光）の分光強度分布を示し、図４（ｂ）は、特殊観察モードにおける照射光Ｌ（特殊光）の分光強度分布を示している。図４に示される分光強度分布の横軸は波長（ｎｍ）を示し、縦軸は照射光Ｌの強度を示している。なお、縦軸は、強度の最大値が１となるように規格化されている。 FIG. 4 shows the spectral intensity distribution of the irradiation light L emitted from the light source device 201 in each observation mode. 4A shows the spectral intensity distribution of the irradiation light L (normal light) in the normal observation mode, and FIG. 4B shows the spectral intensity distribution of the irradiation light L (special light) in the special observation mode. Yes. The horizontal axis of the spectral intensity distribution shown in FIG. 4 indicates the wavelength (nm), and the vertical axis indicates the intensity of the irradiation light L. Note that the vertical axis is standardized so that the maximum intensity value is 1.
　電子内視鏡システム１が通常観察モードである場合、青色蛍光体１１１ｂが光路上に挿入された上で、第１の光源ユニット１１１及び第２の光源ユニット１１２が発光駆動される。 When the electronic endoscope system 1 is in the normal observation mode, the first light source unit 111 and the second light source unit 112 are driven to emit light after the blue phosphor 111b is inserted in the optical path.
　第１の光源ユニット１１１から射出される光の分光強度分布Ｄ１１１は、波長約４１５ｎｍと約４７０ｎｍに強度のピークを有している。なお本願において、この特定の波長のうち最も強度が高い波長をピーク波長と称する。例えば、強度のピークが２つ以上あった場合には、そのうち最も高い強度を持つ波長をピーク波長という。この２つの波長はそれぞれ、紫色ＬＥＤ１１１ａから射出される光のピーク波長と、青色蛍光体１１１ｂが発する蛍光の分光強度分布のピーク波長である。 The spectral intensity distribution D111 of light emitted from the first light source unit 111 has intensity peaks at wavelengths of about 415 nm and about 470 nm. In the present application, a wavelength having the highest intensity among the specific wavelengths is referred to as a peak wavelength. For example, when there are two or more intensity peaks, the wavelength having the highest intensity is called the peak wavelength. These two wavelengths are the peak wavelength of the light emitted from the purple LED 111a and the peak wavelength of the spectral intensity distribution of the fluorescence emitted from the blue phosphor 111b.
　第２の光源ユニット１１２から射出される光の分光強度分布Ｄ１１２は、波長約４５０ｎｍと波長約６００ｎｍにピークを有している。この２つの波長はそれぞれ、青色ＬＥＤ１１２ａから射出される光のピーク波長と、黄色蛍光体１１２ｂが発する蛍光のピーク波長である。 The spectral intensity distribution D112 of light emitted from the second light source unit 112 has peaks at a wavelength of about 450 nm and a wavelength of about 600 nm. These two wavelengths are a peak wavelength of light emitted from the blue LED 112a and a peak wavelength of fluorescence emitted from the yellow phosphor 112b, respectively.
　なお、図４（ａ）に示す分光強度分布Ｄ１１１は、紫色ＬＥＤ光と青色の蛍光のピーク強度が略同じであるが、本発明はこれに限定されない。第１の光源ユニット１１１から射出される紫色ＬＥＤ光と青色の蛍光の強度の比率は、青色蛍光体１１１ｂの種類や使用量を変更することによって自由に変更することができる。また、図４（ａ）に示す分光強度分布Ｄ１１２は、青色ＬＥＤ光と比較して黄色の蛍光の強度の比率が大きいが、本発明はこれに限定されない。第２の光源ユニット１１２から射出される青色ＬＥＤ光と黄色の蛍光の比率は、黄色蛍光体１１２ｂの種類や使用量を変更することによって自由に変更することができる。 In addition, although spectral intensity distribution D111 shown to Fig.4 (a) has substantially the same peak intensity of purple LED light and blue fluorescence, this invention is not limited to this. The ratio of the intensity of the purple LED light emitted from the first light source unit 111 to the intensity of blue fluorescence can be freely changed by changing the type and amount of use of the blue phosphor 111b. Further, the spectral intensity distribution D112 shown in FIG. 4A has a larger ratio of the intensity of yellow fluorescence than that of the blue LED light, but the present invention is not limited to this. The ratio between the blue LED light emitted from the second light source unit 112 and the yellow fluorescence can be freely changed by changing the type and amount of use of the yellow phosphor 112b.
　また、図４（ａ）に示す分光強度分布Ｄ１１１、Ｄ１１２は、強度の最大値が１に揃えられているが、本発明はこれに限定されない。各光源ユニット１１１、１１２から射出される光の強度比は、観察する被写体や撮影モード、術者の好みに応じて任意に設定することができる。 Further, the spectral intensity distributions D111 and D112 shown in FIG. 4A have the maximum intensity values set to 1, but the present invention is not limited to this. The intensity ratio of the light emitted from the light source units 111 and 112 can be arbitrarily set according to the subject to be observed, the photographing mode, and the operator's preference.
　また、図４（ａ）には、ダイクロイックミラー１３１のカットオフ波長λ１３１が点線で示されている。ダイクロイックミラー１３１は、カットオフ波長λ１３１が約５２０ｎｍであり、カットオフ波長λ１３１よりも短い波長帯域の光を透過させ、カットオフ波長λ１３１以上の波長帯域の光を反射する。そのため、図４（ａ）に示される分光強度分布Ｄ１１１のうち、実線で示される波長帯域の光がダイクロイックミラー１３１を透過し、破線で示される波長帯域の光がダイクロイックミラー１３１で反射される。また、図４（ａ）に示される分光強度分布Ｄ１１２のうち、実線で示されるカットオフ波長λ１３１以上の波長帯域の光がダイクロイックミラー１３１で反射され、短い点線で示されるカットオフ波長λ１３１よりも波長帯域の光がダイクロイックミラー１３１を透過する。 In FIG. 4A, the cutoff wavelength λ 131 of the dichroic mirror 131 is indicated by a dotted line. The dichroic mirror 131 has a cutoff wavelength λ131 of about 520 nm, transmits light in a wavelength band shorter than the cutoff wavelength λ131, and reflects light in a wavelength band longer than the cutoff wavelength λ131. Therefore, in the spectral intensity distribution D111 shown in FIG. 4A, light in the wavelength band indicated by the solid line passes through the dichroic mirror 131, and light in the wavelength band indicated by the broken line is reflected by the dichroic mirror 131. Also, in the spectral intensity distribution D112 shown in FIG. 4A, light in a wavelength band equal to or greater than the cutoff wavelength λ131 indicated by the solid line is reflected by the dichroic mirror 131, and is shorter than the cutoff wavelength λ131 indicated by the short dotted line. Light in the wavelength band passes through the dichroic mirror 131.
　これにより、ダイクロイックミラー１３１で、各光源ユニット１１１、１１２から射出された光の光路が合成され、光源装置２０１からは、紫外領域（近紫外の一部）から赤色領域にかけて広い波長帯域を有する照射光Ｌ（通常光）が射出される。この照射光Ｌ（通常光）の分光強度分布は、図４（ａ）に示す分光強度分布Ｄ１１１、Ｄ１１２のうち、実線で示される領域を足し合わせたものになる。照射光Ｌ（通常光）を被写体に照射することにより、通常のカラー撮影画像を得ることができる。 As a result, the optical paths of the light emitted from the light source units 111 and 112 are synthesized by the dichroic mirror 131, and the light source device 201 emits light having a wide wavelength band from the ultraviolet region (part of the near ultraviolet) to the red region. Light L (normal light) is emitted. The spectral intensity distribution of the irradiation light L (normal light) is the sum of the areas indicated by the solid lines in the spectral intensity distributions D111 and D112 shown in FIG. By irradiating the subject with the irradiation light L (normal light), a normal color photographed image can be obtained.
　また、電子内視鏡システム１が特殊観察モードである場合、青色蛍光体１１１ｂが光路上から抜去された上で、第１の光源ユニット１１１及び第２の光源ユニット１１２が発光駆動される。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の光の比率が相対的に高くなり（すなわち狭帯域光となり）、表層血管が強調された撮影画像を得ることができる。また、第２の光源ユニット１１２から射出される光は、ヘモグロビンの吸光度のもう一つのピークとなる波長５５０ｎｍ付近の光を含んでいる。そのため、第１の光源ユニット１１１と共に、第２の光源ユニット１１２を発光駆動することにより、表層血管が強調された状態を維持しつつ、撮影画像の輝度を上げることができる。 Further, when the electronic endoscope system 1 is in the special observation mode, the first light source unit 111 and the second light source unit 112 are driven to emit light after the blue phosphor 111b is removed from the optical path. As a result, the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained. Obtainable. The light emitted from the second light source unit 112 includes light having a wavelength near 550 nm, which is another peak of the absorbance of hemoglobin. Therefore, by driving the second light source unit 112 to emit light together with the first light source unit 111, the brightness of the photographed image can be increased while maintaining the state where the surface blood vessels are emphasized.
　また、本実施形態では、特定の波長帯域の光のみを透過させる光学フィルタを使用することなく、青色蛍光体１１１ｂを光路上に挿抜することによって、照射光Ｌを通常光と特殊光との間で切り替えている。そのため、光学フィルタによって被写体の観察に使用されない波長帯域の光がカットされ、第１の光源ユニットの光利用効率が低下してしまうことを防止できる。 In the present embodiment, the blue phosphor 111b is inserted into and removed from the optical path without using an optical filter that transmits only light in a specific wavelength band, so that the irradiation light L is changed between normal light and special light. Switching with. Therefore, it is possible to prevent light in a wavelength band that is not used for observing the subject by the optical filter from being cut and the light use efficiency of the first light source unit from being lowered.
　更に、仮に、第１の光源ユニットから射出された紫色ＬＥＤ光及び青色の蛍光から、光学フィルタを用いて紫色ＬＥＤ光を抽出する場合、光学フィルタが理想的な特性を有していない限り、照射光Ｌには青色の蛍光も混ざってしまう。青色の蛍光は表層血管の強調した撮影画像を得るのに不要な光であるため、照射光Ｌに青色の蛍光が混ざることにより、表層血管の強調効果が低減する。これに対し、本実施形態では、光学フィルタを用いることなく、青色の蛍光を完全に抑えることができるため、表層血管の強調効果が低減してしまうことを防止することができる。 Furthermore, if the purple LED light is extracted from the purple LED light and blue fluorescence emitted from the first light source unit using the optical filter, the irradiation is performed unless the optical filter has ideal characteristics. The light L is also mixed with blue fluorescence. Since the blue fluorescence is unnecessary light for obtaining a photographed image in which the superficial blood vessels are emphasized, the effect of superficial blood vessels is reduced by mixing the blue light with the irradiation light L. On the other hand, in this embodiment, since the blue fluorescence can be completely suppressed without using an optical filter, it is possible to prevent the enhancement effect of the surface blood vessels from being reduced.
　また、各光源ユニット１１１、１１２から射出された光は、ダイクロイックミラー１３１によってその光路が合成される。このとき、各光源ユニット１１１、１１２から射出される光の波長帯域は互いに異なるため、ダイクロイックミラー１３１での光路の合成時において、光量の損失を最小限に抑えることができる。 Further, the light paths of the light emitted from the light source units 111 and 112 are combined by the dichroic mirror 131. At this time, since the wavelength bands of the light emitted from the light source units 111 and 112 are different from each other, the loss of the light amount can be minimized when the optical paths in the dichroic mirror 131 are combined.
　例えば、特殊観察モードにおいて、従来技術のように、実質的に特定の波長帯域の光のみを透過させる光学フィルタを使用する場合、特定の波長帯域以外の光を無駄に発光させる必要があり、光源装置の光利用効率が低い。これに対し、本発明の第１の実施形態では、図４に示されるように、ダイクロイックミラー１３１における光路の合成により照射光Ｌとして使用されない光（図４で破線で示された領域の光）は、照射光Ｌとして使用される光（図４で実線で示された領域の光）に比べて、その光量が小さい。そのため、本実施形態の光源装置２０１では、被写体に照射されない波長帯域の光を無駄に発光させる必要がなく、従来技術に比べて光利用効率を高くすることができる。 For example, in the special observation mode, when using an optical filter that substantially transmits only light in a specific wavelength band as in the prior art, it is necessary to waste light other than the specific wavelength band. The light utilization efficiency of the device is low. On the other hand, in the first embodiment of the present invention, as shown in FIG. 4, light that is not used as irradiation light L by combining optical paths in the dichroic mirror 131 (light in a region indicated by a broken line in FIG. 4) Is smaller in amount of light than the light used as the irradiation light L (the light in the region indicated by the solid line in FIG. 4). Therefore, in the light source device 201 of the present embodiment, it is not necessary to wastefully emit light in a wavelength band that is not irradiated on the subject, and the light use efficiency can be increased as compared with the related art.
　また、比較的広い空間を持つ部位（例えば胃）を観察する場合、典型的には、電子スコープ１００の先端部から被写体（例えば胃壁）までの距離が遠いため、被写体に照射される照射光の強度が低くなる。明るい撮影画像を得るためには、高い強度の照射光で被写体を照明する必要がある。本実施形態の光源装置２０１は、特殊観察モードにおいて光学フィルタを使用せず、高い光利用効率を有しているため、被写体に照射される照射光の強度を高くすることができる。そのため、胃などの部位を観察する場合にも、明るい撮影画像を得ることができる。 Further, when observing a part having a relatively large space (for example, the stomach), since the distance from the distal end portion of the electronic scope 100 to the subject (for example, the stomach wall) is typically far, Strength is lowered. In order to obtain a bright photographed image, it is necessary to illuminate the subject with high intensity irradiation light. Since the light source device 201 of the present embodiment does not use an optical filter in the special observation mode and has high light use efficiency, it is possible to increase the intensity of irradiation light irradiated on the subject. Therefore, a bright captured image can be obtained even when observing a site such as the stomach.
　なお、電子内視鏡システム１が特殊観察モードである場合、図４（ｂ）に示すように、分光強度分布Ｄ１１１とＤ１１２のピーク強度はいずれも１に揃えられているが、本発明はこれに限定されない。例えば、特殊観察モードでは、第２の光源ユニット１１２は、通常観察モード時よりも、駆動電流を小さくし、強度が低くなるように発光駆動されてもよい。これにより、ヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の強度が、他の波長帯域の強度よりも相対的に高くなり（すなわち狭帯域光となり）、より表層血管が強調された撮影画像を得ることができる。 Note that when the electronic endoscope system 1 is in the special observation mode, as shown in FIG. 4B, the peak intensities of the spectral intensity distributions D111 and D112 are all set to 1, but the present invention is not limited to this. It is not limited to. For example, in the special observation mode, the second light source unit 112 may be driven to emit light so that the drive current is smaller and the intensity is lower than that in the normal observation mode. As a result, the intensity around the wavelength of 415 nm, which is the peak of hemoglobin absorbance, is relatively higher than the intensity of other wavelength bands (that is, becomes narrowband light), and a captured image in which the surface blood vessels are more emphasized is obtained. Can do.
　なお、本実施形態において用いられる蛍光体には下記のものが例示として挙げられる。大分類として、酸化物系蛍光体と窒化物系蛍光体が挙げられる。 In addition, the following are mentioned as an example for the fluorescent substance used in this embodiment. As a broad classification, oxide phosphors and nitride phosphors can be mentioned.
《酸化物系蛍光体》
〈黄色蛍光体〉
・Ｙ３Ａｌ５Ｏ１２（イットリウムアルミニウム酸化物）を母体結晶とする黄色蛍光体
〈緑色蛍光体〉
・Ｃａ３Ｓｃ２Ｓｉ３Ｏ１２（カルシウムスカンジウムケイ素酸化物）を母体結晶としてＣｅを付活させた緑色蛍光体
・ＣａＳｃ２Ｏ４（カルシウムスカンジウム酸化物）を母体結晶としてＣｅを付活させた緑色蛍光体 <Oxide-based phosphor>
<Yellow phosphor>
・ Yellow phosphor (green phosphor) having Y 3 Al 5 O 12 (yttrium aluminum oxide) as a base crystal
・ Green phosphor with activated Ca 3 Sc 2 Si 3 O 12 (calcium scandium silicon oxide) as a base crystal ・ Ce activated with CaSc 2 O 4 (calcium scandium oxide) as a base crystal Green phosphor
《窒化物系蛍光体》
〈赤色蛍光体〉
・母体結晶としてＥｕを付活させたカルシウムアルミニウムケイ素窒化物（ＣａＡｌＳｉＮ３）にケイ素酸窒化物（Ｓｉ２Ｎ２Ｏ）を固溶させた赤色蛍光体
〈その他の蛍光体〉
・母体となるセラミックス結晶に希土類元素等の発光を担う金属イオンを微量添加したサイアロン蛍光体、α型窒化ケイ素（Ｓｉ３Ｎ４）結晶の固溶体であるα－サイアロン蛍光体、窒化カルシウムアルミニウムケイ素（ＣａＡｌＳｉＮ３）蛍光体など <Nitride phosphor>
<Red phosphor>
・ Red phosphor in which silicon oxynitride (Si 2 N 2 O) is dissolved in calcium aluminum silicon nitride (CaAlSiN 3 ) activated with Eu as a base crystal <other phosphors>
・ Sialon phosphors with a small amount of metal ions responsible for light emission such as rare earth elements added to the base ceramic crystal, α-sialon phosphors that are solid solutions of α-type silicon nitride (Si 3 N 4 ) crystals, calcium aluminum silicon nitride ( CaAlSiN 3 ) phosphor etc.
（第２の実施形態）
　次に、本発明の第２の実施形態にかかる内視鏡用光源装置について説明する。第２の実施形態にかかる光源装置も、第１の実施形態にかかる光源装置２０１と同様に、電子内視鏡システム１において使用される。 (Second Embodiment)
Next, an endoscope light source device according to a second embodiment of the present invention will be described. The light source device according to the second embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
　図５は、第２の実施形態に係る光源装置２０２のうち、光源ユニットおよびダイクロイックミラーのみを概念的に示したブロック図である。光源装置２０２は、第１の光源ユニット２１１、第２の光源ユニット２１２、第１のダイクロイックミラー２３１を備えている。各光源ユニット２１１、２１２はそれぞれ、図示省略された第１光源駆動回路、第２光源駆動回路によって個別に発光制御される。 FIG. 5 is a block diagram conceptually showing only the light source unit and the dichroic mirror in the light source device 202 according to the second embodiment. The light source device 202 includes a first light source unit 211, a second light source unit 212, and a first dichroic mirror 231. The light source units 211 and 212 are individually controlled to emit light by a first light source drive circuit and a second light source drive circuit (not shown).
　図５に示すように、第１の光源ユニット２１１は、紫色の波長帯域（例えば、波長が３９５～４３５ｎｍ）の光を射出する紫色ＬＥＤ２１１ａと、青色蛍光体２１１ｂとを有している。青色蛍光体２１１ｂは、紫色ＬＥＤ２１１ａから射出された紫色ＬＥＤ光によって励起され、青色の波長帯域（例えば、波長４３０～５５０ｎｍ）の蛍光を発する。青色蛍光体２１１ｂは、不図示の蛍光体挿抜機構により、紫色ＬＥＤ２１１ａから射出された紫色ＬＥＤ光の光路に対して挿抜可能に支持されている。なお、青色蛍光体２１１ｂは、紫色ＬＥＤ２１１ａとは別体であるため、図５において、青色蛍光体２１１ｂと紫色ＬＥＤ２１１ａは、別々のブロックで示されている。 As shown in FIG. 5, the first light source unit 211 has a purple LED 211a that emits light in a purple wavelength band (for example, a wavelength of 395 to 435 nm) and a blue phosphor 211b. The blue phosphor 211b is excited by the purple LED light emitted from the purple LED 211a and emits fluorescence in a blue wavelength band (for example, a wavelength of 430 to 550 nm). The blue phosphor 211b is supported by an unillustrated phosphor insertion / extraction mechanism so that the blue phosphor 211b can be inserted into and removed from the optical path of the purple LED light emitted from the purple LED 211a. Since the blue phosphor 211b is separate from the purple LED 211a, the blue phosphor 211b and the purple LED 211a are shown as separate blocks in FIG.
　また、図５に示すように、第２の光源ユニット２１２は、青色の波長帯域（例えば、波長が４２０～４８０ｎｍ）の光を射出する青色ＬＥＤ、緑色蛍光体、赤色蛍光体を有している。緑色蛍光体は、青色ＬＥＤから射出された青色ＬＥＤ光によって励起され、緑色の波長帯域（例えば、波長が５１０～６３０ｎｍ）の蛍光を発する。赤色蛍光体は、青色ＬＥＤから射出された青色ＬＥＤ光によって励起され、赤色の波長帯域（例えば、波長が５５０～７５０ｎｍ）の蛍光を発する。なお、緑色蛍光体と赤色蛍光体は、青色ＬＥＤ光の射出方向に沿って並べて配置されていてもよく、青色ＬＥＤ光の射出方向と垂直な方向に並べて配置されていてもよい。また、緑色蛍光体と赤色蛍光体は、その材料が混ぜ合わせられ、一つの蛍光体として作成されたものであってもよい。 Further, as shown in FIG. 5, the second light source unit 212 includes a blue LED, a green phosphor, and a red phosphor that emit light in a blue wavelength band (for example, a wavelength of 420 to 480 nm). . The green phosphor is excited by blue LED light emitted from the blue LED, and emits fluorescence in a green wavelength band (for example, a wavelength of 510 to 630 nm). The red phosphor is excited by the blue LED light emitted from the blue LED and emits fluorescence in the red wavelength band (for example, the wavelength is 550 to 750 nm). The green phosphor and the red phosphor may be arranged side by side along the emission direction of blue LED light, or may be arranged side by side in a direction perpendicular to the emission direction of blue LED light. The green phosphor and the red phosphor may be prepared as a single phosphor by mixing the materials.
　各光源ユニット２１１、２１２の射出方向の前方にはそれぞれ、図示省略されたコリメートレンズが配置されている。第１の光源ユニット２１１から射出された光は、コリメートレンズによって平行光に変換され、ダイクロイックミラー２３１に入射される。また、第２の光源ユニット２１２から射出された光は、コリメートレンズによって平行光に変換され、ダイクロイックミラー２３１に入射される。ダイクロイックミラー２３１は、第１の光源ユニット２１１から射出された光の光路と第２の光源ユニット２１２から射出された光の光路を合成する。ダイクロイックミラー２３１で光路が合成された光は、照射光Ｌとして光源装置２０２から射出される。 A collimating lens (not shown) is arranged in front of the light source units 211 and 212 in the emission direction. The light emitted from the first light source unit 211 is converted into parallel light by the collimator lens and is incident on the dichroic mirror 231. The light emitted from the second light source unit 212 is converted into parallel light by the collimator lens and is incident on the dichroic mirror 231. The dichroic mirror 231 combines the optical path of the light emitted from the first light source unit 211 and the optical path of the light emitted from the second light source unit 212. The light whose optical path is synthesized by the dichroic mirror 231 is emitted from the light source device 202 as irradiation light L.
　図６は、図４と同様の図であり、各観察モードにおいて、光源装置２０２から射出される照射光Ｌの分光強度分布を示している。 FIG. 6 is a view similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 202 in each observation mode.
　電子内視鏡システム１が通常観察モードである場合、青色蛍光体２１１ｂが光路上に挿入された上で、第１の光源ユニット２１１と第２の光源ユニット２１２の両方が発光駆動される。 When the electronic endoscope system 1 is in the normal observation mode, both the first light source unit 211 and the second light source unit 212 are driven to emit light after the blue phosphor 211b is inserted in the optical path.
　第１の光源ユニット２１１から射出される光の分光強度分布Ｄ２１１は、波長約４１５ｎｍと波長約４７０ｎｍにピークを有している。この２つの波長はそれぞれ、紫色ＬＥＤ２１１ａから射出される光のピーク波長と、青色蛍光体２１１ｂが発する蛍光のピーク波長である。 The spectral intensity distribution D211 of light emitted from the first light source unit 211 has peaks at a wavelength of about 415 nm and a wavelength of about 470 nm. These two wavelengths are a peak wavelength of light emitted from the purple LED 211a and a peak wavelength of fluorescence emitted from the blue phosphor 211b, respectively.
　第２の光源ユニット２１２から射出される光の分光強度分布Ｄ２１２は、波長約４５０ｎｍ、約５５０ｎｍ、約６５０ｎｍにピークを有している。この３つの波長はそれぞれ、青色ＬＥＤ光、緑色蛍光体が発する蛍光、赤色蛍光体が発する蛍光のピーク波長である。 The spectral intensity distribution D212 of light emitted from the second light source unit 212 has peaks at wavelengths of about 450 nm, about 550 nm, and about 650 nm. These three wavelengths are respectively the peak wavelengths of blue LED light, fluorescence emitted by the green phosphor, and fluorescence emitted by the red phosphor.
　また、図６（ａ）には、ダイクロイックミラー２３１のカットオフ波長λ２３１が点線で示されている。ダイクロイックミラー２３１は、カットオフ波長λ２３１が約５１０ｎｍであり、カットオフ波長λ２３１よりも短い波長帯域の光を透過させ、カットオフ波長λ２３１以上の波長帯域の光を反射する。そのため、図４（ａ）に示される分光強度分布Ｄ２１１のうち、実線で示される波長帯域の光がダイクロイックミラー２３１を透過し、破線で示される波長帯域の光がダイクロイックミラー２３１で反射される。また、図４（ａ）に示される分光強度分布Ｄ２１２のうち、実線で示される波長帯域の光がダイクロイックミラー２３１で反射され、破線で示される波長帯域の光がダイクロイックミラー２３１を透過する。 In FIG. 6A, the cutoff wavelength λ231 of the dichroic mirror 231 is indicated by a dotted line. The dichroic mirror 231 has a cutoff wavelength λ231 of about 510 nm, transmits light in a wavelength band shorter than the cutoff wavelength λ231, and reflects light in a wavelength band longer than the cutoff wavelength λ231. Therefore, in the spectral intensity distribution D211 shown in FIG. 4A, light in the wavelength band indicated by the solid line passes through the dichroic mirror 231 and light in the wavelength band indicated by the broken line is reflected by the dichroic mirror 231. Also, in the spectral intensity distribution D212 shown in FIG. 4A, light in the wavelength band indicated by the solid line is reflected by the dichroic mirror 231 and light in the wavelength band indicated by the broken line passes through the dichroic mirror 231.
　これにより、ダイクロイックミラー２３１で、各光源ユニット２１１、２１２から射出された光の光路が合成され、光源装置２０２からは、紫外領域（近紫外の一部）から赤色領域にかけて広い波長帯域を有する照射光Ｌ（通常光）が射出される。この照射光Ｌ（通常光）の分光強度分布は、図６（ａ）に示す分光強度分布Ｄ２１１、Ｄ２１２のうち、実線で示される領域を足し合わせたものになる。この照射光Ｌ（通常光）を被写体に照射することにより、通常のカラー撮影画像を得ることができる。 Thereby, the optical path of the light emitted from each of the light source units 211 and 212 is synthesized by the dichroic mirror 231, and the light source device 202 emits light having a wide wavelength band from the ultraviolet region (part of near ultraviolet) to the red region. Light L (normal light) is emitted. The spectral intensity distribution of the irradiation light L (normal light) is the sum of the areas indicated by the solid lines in the spectral intensity distributions D211 and D212 shown in FIG. By irradiating the subject with the irradiation light L (normal light), a normal color photographed image can be obtained.
　また、電子内視鏡システム１が特殊観察モードである場合、青色蛍光体２１１ｂが光路上から抜去された上で、第１の光源ユニット２１１と第２の光源ユニット２１２の両方が発光駆動される。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の光の比率が相対的に高くなり（すなわち狭帯域光となり）、表層血管が強調された撮影画像を得ることができる。 Further, when the electronic endoscope system 1 is in the special observation mode, both the first light source unit 211 and the second light source unit 212 are driven to emit light after the blue phosphor 211b is removed from the optical path. . As a result, the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained. Obtainable.
　また、第２の光源ユニット２１２は、緑色蛍光体と赤色蛍光体の２つの蛍光体を有している。そのため、電子内視鏡システム１が通常観察モードである場合の照射光Ｌ（通常光）の分光強度分布は、第２の光源ユニット２１２が１つの蛍光体を有している場合よりも、可視領域においてフラットに近づく。これにより、通常観察モードにおいて、自然の白色光に近い照射光Ｌ（通常光）で被写体を照明することができる。 The second light source unit 212 has two phosphors, a green phosphor and a red phosphor. Therefore, the spectral intensity distribution of the irradiation light L (normal light) when the electronic endoscope system 1 is in the normal observation mode is more visible than when the second light source unit 212 has one phosphor. It approaches flat in the area. Thereby, in the normal observation mode, the subject can be illuminated with the irradiation light L (normal light) close to natural white light.
（第３の実施形態）
　次に、本発明の第３の実施形態にかかる内視鏡用光源装置について説明する。第３の実施形態にかかる光源装置も、第１の実施形態にかかる光源装置２０１と同様に、電子内視鏡システム１において使用される。 (Third embodiment)
Next, an endoscope light source device according to a third embodiment of the present invention will be described. The light source device according to the third embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
　図７は、第３の実施形態に係る光源装置２０３のうち、光源ユニットおよびダイクロイックミラーのみを概念的に示したブロック図である。光源装置２０３は、第１の光源ユニット３１１、第２の光源ユニット３１２、第３の光源ユニット３１３、第１のダイクロイックミラー３３１、第２のダイクロイックミラー３３２を備えている。各光源ユニット３１１～３１３はそれぞれ、図示省略された第１～第３光源駆動回路によって個別に発光制御される。 FIG. 7 is a block diagram conceptually showing only the light source unit and the dichroic mirror in the light source device 203 according to the third embodiment. The light source device 203 includes a first light source unit 311, a second light source unit 312, a third light source unit 313, a first dichroic mirror 331, and a second dichroic mirror 332. The light source units 311 to 313 are individually controlled to emit light by first to third light source driving circuits (not shown).
　図７に示すように、第３の実施形態に係る光源装置２０３は、第１の実施形態に係る光源装置２０１に、第３の光源ユニット３１３及び第２のダイクロイックミラー３３２を追加した構成である。また、第１の光源ユニット３１１、第２の光源ユニット３１２、ダイクロイックミラー３３１の特性はそれぞれ、第１の実施形態の第１の光源ユニット１１１、第２の光源ユニット１１２、ダイクロイックミラー１３１の特性と同じである。第３の光源ユニット３１３は、赤色の波長帯域（例えば、波長が６２０～６８０ｎｍ）の光を射出する赤色ＬＥＤである。ダイクロイックミラー３３２のカットオフ波長λ３３２は６３０ｎｍである。ダイクロイックミラー３３２は、カットオフ波長よりも短い波長帯域の光を透過させ、カットオフ波長以上の波長帯域の光を反射する。 As illustrated in FIG. 7, the light source device 203 according to the third embodiment has a configuration in which a third light source unit 313 and a second dichroic mirror 332 are added to the light source device 201 according to the first embodiment. . The characteristics of the first light source unit 311, the second light source unit 312, and the dichroic mirror 331 are the characteristics of the first light source unit 111, the second light source unit 112, and the dichroic mirror 131 of the first embodiment, respectively. The same. The third light source unit 313 is a red LED that emits light in a red wavelength band (for example, a wavelength of 620 to 680 nm). The cut-off wavelength λ332 of the dichroic mirror 332 is 630 nm. The dichroic mirror 332 transmits light in a wavelength band shorter than the cutoff wavelength and reflects light in a wavelength band equal to or greater than the cutoff wavelength.
　図８は、図４と同様の図であり、各観察モードにおいて、光源装置２０３から射出される照射光Ｌの分光強度分布を示している。 FIG. 8 is a diagram similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 203 in each observation mode.
　電子内視鏡システム１が通常観察モードである場合、青色蛍光体３１１ｂが光路上に挿入された上で、第１～第３光源ユニット３１１～３１３が発光駆動される。図８（ａ）に示すように、第３の実施形態における照射光Ｌの分光強度分布は、第１の実施形態における照射光Ｌに、赤色ＬＥＤ３１３の分光強度分布Ｄ３１３を追加したものになる。ただし、第３の実施形態の光源装置２０３は、第１の実施形態とは異なり、ダイクロイックミラー３３２を有しているため、第２の光源ユニット３１２から射出された光のうち、ダイクロイックミラー３３２のカットオフ波長λ３３２（６３０ｎｍ）以上の波長の光の光路は、ダイクロイックミラー３３２で合成されず、照射光Ｌとして射出されない。また、第３の光源ユニット３１３から射出された光のうち、カットオフ波長λ３３２よりも波長の短い光の光路は、ダイクロイックミラー３３２で合成されず、照射光Ｌとして射出されない。 When the electronic endoscope system 1 is in the normal observation mode, the first to third light source units 311 to 313 are driven to emit light after the blue phosphor 311b is inserted in the optical path. As shown in FIG. 8A, the spectral intensity distribution of the irradiation light L in the third embodiment is obtained by adding the spectral intensity distribution D313 of the red LED 313 to the irradiation light L in the first embodiment. However, since the light source device 203 of the third embodiment has a dichroic mirror 332 unlike the first embodiment, of the light emitted from the second light source unit 312, the light source device 203 of the dichroic mirror 332. The optical path of light having a wavelength longer than the cutoff wavelength λ332 (630 nm) is not synthesized by the dichroic mirror 332 and is not emitted as the irradiation light L. Of the light emitted from the third light source unit 313, the optical path of light having a wavelength shorter than the cutoff wavelength λ332 is not synthesized by the dichroic mirror 332 and is not emitted as the irradiation light L.
　第３の実施形態の光源装置２０３は、赤色ＬＥＤ３１３を有している。そのため、電子内視鏡システム１が通常観察モードである場合の照射光Ｌ（通常光）の分光強度分布は、赤色ＬＥＤ３１３を有していない構成に比べて、可視領域においてフラットに近づく。これにより、通常観察モードにおいて、自然の白色光に近い照射光Ｌ（通常光）で被写体を照明することができる。 The light source device 203 of the third embodiment has a red LED 313. Therefore, the spectral intensity distribution of the irradiation light L (normal light) in the case where the electronic endoscope system 1 is in the normal observation mode is closer to flat in the visible region than in the configuration without the red LED 313. Thereby, in the normal observation mode, the subject can be illuminated with the irradiation light L (normal light) close to natural white light.
　また、電子内視鏡システム１が特殊観察モードである場合、青色蛍光体２１１ｂが光路上から抜去された上で、第１の光源ユニット３１１及び第２の光源ユニット３１２が発光駆動され、第３の光源ユニット３１３は発光駆動されない。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の光の比率が相対的に高くなり（すなわち狭帯域光となり）、表層血管が強調された撮影画像を得ることができる。 When the electronic endoscope system 1 is in the special observation mode, the first phosphor unit 311 and the second light source unit 312 are driven to emit light after the blue phosphor 211b is removed from the optical path, and the third light source unit 312 is driven to emit light. The light source unit 313 is not driven to emit light. As a result, the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained. Obtainable.
　また、第３の実施形態の光源装置２０３は、波長帯域が異なり、それぞれ個別に発光制御可能な３つの光源ユニット３１１～３１３を有している。そのため、３つの光源ユニット３１１～３１３の中から発光駆動させる光源ユニットを選択し、発光駆動時の駆動電流を個別に制御することにより、照射光Ｌの分光強度分布を細かく制御することができる。 In addition, the light source device 203 of the third embodiment has three light source units 311 to 313 having different wavelength bands and capable of individually controlling light emission. Therefore, the spectral intensity distribution of the irradiation light L can be finely controlled by selecting a light source unit to be driven for light emission from among the three light source units 311 to 313 and individually controlling the drive current during the light emission drive.
（第４の実施形態）
　次に、本発明の第４の実施形態にかかる内視鏡用光源装置について説明する。第４の実施形態にかかる光源装置も、第１の実施形態にかかる光源装置２０１と同様に、電子内視鏡システム１において使用される。 (Fourth embodiment)
Next, an endoscope light source device according to a fourth embodiment of the present invention will be described. The light source device according to the fourth embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
　図９は、第４の実施形態に係る光源装置２０４のうち、光源ユニットおよびダイクロイックミラーのみを概念的に示したブロック図である。光源装置２０４は、第１の光源ユニット４１１、第２の光源ユニット４１２、第３の光源ユニット４１３、第１のダイクロイックミラー４３１、第２のダイクロイックミラー４３２を備えている。各光源ユニット４１１～４１３はそれぞれ、図示省略された第１～第３光源駆動回路によって個別に発光制御される。 FIG. 9 is a block diagram conceptually showing only the light source unit and the dichroic mirror in the light source device 204 according to the fourth embodiment. The light source device 204 includes a first light source unit 411, a second light source unit 412, a third light source unit 413, a first dichroic mirror 431, and a second dichroic mirror 432. The light source units 411 to 413 are individually controlled to emit light by first to third light source driving circuits (not shown).
　図９に示すように、第４の実施形態に係る光源装置２０４は、第３の実施形態に係る光源装置２０３における第２の光源ユニット３１２を、蛍光体を有しないＬＥＤに置き換えたものである。第２の光源ユニット４１２は、緑色の波長帯域（例えば、波長が５２０～５８０ｎｍ）の光を射出する緑色ＬＥＤである。なお、第１、第３の光源ユニット４１１、４１３及び第１、第２のダイクロイックミラー４３１、４３２の特性は、第３の実施形態の第１、第３の光源ユニット３１１、３１３及び第１、第２のダイクロイックミラー３３１、３３２の特性と同じである必要はない。 As shown in FIG. 9, the light source device 204 according to the fourth embodiment is obtained by replacing the second light source unit 312 in the light source device 203 according to the third embodiment with an LED having no phosphor. . The second light source unit 412 is a green LED that emits light in a green wavelength band (for example, a wavelength of 520 to 580 nm). The characteristics of the first and third light source units 411 and 413 and the first and second dichroic mirrors 431 and 432 are the same as those of the first and third light source units 311 and 313 and the first and second light source units 311 and 313 of the third embodiment. The characteristics of the second dichroic mirrors 331 and 332 need not be the same.
　図１０は、図４と同様の図であり、各観察モードにおいて、光源装置２０４から射出される照射光Ｌの分光強度分布を示している。 FIG. 10 is a view similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 204 in each observation mode.
　電子内視鏡システム１が通常観察モードである場合、青色蛍光体４１１ｂが光路上に挿入された上で、第１～第３の光源ユニット３１１～３１３が発光駆動される。 When the electronic endoscope system 1 is in the normal observation mode, the first to third light source units 311 to 313 are driven to emit light after the blue phosphor 411b is inserted in the optical path.
　第１の光源ユニット４１１から射出される光の分光強度分布Ｄ４１１は、波長約４１５ｎｍと波長約４７０ｎｍにピークを有している。この２つの波長はそれぞれ、紫色ＬＥＤ４１１ａから射出される光のピーク波長と、青色蛍光体４１１ｂが発する蛍光のピーク波長である。第２の光源ユニット４１２から射出される光の分光強度分布Ｄ４１２は、約５５０ｎｍをピーク波長とする強度分布を有している。第３の光源ユニット４１３から射出される光の分光強度分布Ｄ４１３は、約６４０ｎｍをピーク波長とする強度分布を有している。 The spectral intensity distribution D411 of light emitted from the first light source unit 411 has peaks at a wavelength of about 415 nm and a wavelength of about 470 nm. These two wavelengths are a peak wavelength of light emitted from the purple LED 411a and a peak wavelength of fluorescence emitted from the blue phosphor 411b, respectively. The spectral intensity distribution D412 of the light emitted from the second light source unit 412 has an intensity distribution with a peak wavelength of about 550 nm. The spectral intensity distribution D413 of light emitted from the third light source unit 413 has an intensity distribution with a peak wavelength of about 640 nm.
　また、図１０（ａ）には、各ダイクロイックミラー４３１、４３２のカットオフ波長λ４３１、λ４３２が点線で示されている。カットオフ波長λ４３１、λ４３２はそれぞれ、５１０ｎｍ、５９０ｎｍである。何れのダイクロイックミラー４３１、４３２も、カットオフ波長よりも短い波長帯域の光を透過させ、カットオフ波長以上の波長帯域の光を反射する。このダイクロイックミラー４３１、４３２により、各光源ユニット４１１～４１３から射出された光の光路が合成され、照射光Ｌ（通常光）として射出される。この照射光Ｌ（通常光）を被写体に照射することにより、通常のカラー撮影画像を得ることができる。 In FIG. 10A, the cutoff wavelengths λ431 and λ432 of the dichroic mirrors 431 and 432 are indicated by dotted lines. Cutoff wavelengths λ431 and λ432 are 510 nm and 590 nm, respectively. Any of the dichroic mirrors 431 and 432 transmits light having a wavelength band shorter than the cutoff wavelength, and reflects light having a wavelength band equal to or greater than the cutoff wavelength. By the dichroic mirrors 431 and 432, the optical paths of the light emitted from the light source units 411 to 413 are combined and emitted as irradiation light L (normal light). By irradiating the subject with the irradiation light L (normal light), a normal color photographed image can be obtained.
　また、電子内視鏡システム１が特殊観察モードである場合、青色蛍光体４１１ｂが光路上から抜去された上で、第１の光源ユニット４１１と第２の光源ユニット４１２が発光駆動され、第３の光源ユニット４１３は発光駆動されない。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の光の比率が相対的に高くなり（すなわち狭帯域光となり）、表層血管が強調された撮影画像を得ることができる。 Further, when the electronic endoscope system 1 is in the special observation mode, the first light source unit 411 and the second light source unit 412 are driven to emit light after the blue phosphor 411b is removed from the optical path, and the third The light source unit 413 is not driven to emit light. As a result, the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained. Obtainable.
（第５の実施形態）
　次に、本発明の第５の実施形態にかかる内視鏡用光源装置について説明する。第５の実施形態にかかる光源装置も、第１の実施形態にかかる光源装置２０１と同様に、電子内視鏡システム１において使用される。 (Fifth embodiment)
Next, an endoscope light source device according to a fifth embodiment of the present invention will be described. The light source device according to the fifth embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
　図１１は、第５の実施形態に係る光源装置２０５のうち、光源ユニットおよびダイクロイックミラーのみを概念的に示したブロック図である。光源装置２０５は、第１の光源ユニット５１１、第２の光源ユニット５１２、第１のダイクロイックミラー５３１を備えている。各光源ユニット５１１、５１２はそれぞれ、図示省略された第１、第２光源駆動回路によって個別に発光制御される。 FIG. 11 is a block diagram conceptually showing only the light source unit and the dichroic mirror in the light source device 205 according to the fifth embodiment. The light source device 205 includes a first light source unit 511, a second light source unit 512, and a first dichroic mirror 531. The light source units 511 and 512 are individually controlled to emit light by first and second light source driving circuits (not shown).
　図１１に示すように、第１の光源ユニット５１１は、蛍光体ＬＥＤ５１１ａと青色蛍光体５１１ｂとを有している。蛍光体ＬＥＤ５１１ａは、紫色の波長帯域（例えば、波長が３９５～４３５ｎｍ）の光を射出する紫色ＬＥＤと、この紫色ＬＥＤの発光面上に取り付けられた緑色蛍光体とを有している。緑色蛍光体は、紫色ＬＥＤから射出された紫色ＬＥＤ光によって励起され、緑色の波長帯域（例えば、波長が５１０～６３０ｎｍ）の蛍光を発する。青色蛍光体５１１ｂは、紫色ＬＥＤから射出された紫色ＬＥＤ光によって励起され、青色の波長帯域（例えば、波長が４３０～５５０ｎｍ）の蛍光を発する。青色蛍光体５１１ｂは、不図示の蛍光体挿抜機構により、蛍光体ＬＥＤ５１１ａから射出される光の光路に対して挿抜可能に支持されている。 As shown in FIG. 11, the first light source unit 511 includes a phosphor LED 511a and a blue phosphor 511b. The phosphor LED 511a has a purple LED that emits light in a purple wavelength band (for example, a wavelength of 395 to 435 nm), and a green phosphor attached on the light emitting surface of the purple LED. The green phosphor is excited by the purple LED light emitted from the purple LED, and emits fluorescence in the green wavelength band (for example, the wavelength is 510 to 630 nm). The blue phosphor 511b is excited by the violet LED light emitted from the violet LED, and emits fluorescence in a blue wavelength band (for example, the wavelength is 430 to 550 nm). The blue phosphor 511b is supported by an unillustrated phosphor insertion / extraction mechanism so as to be insertable / removable with respect to the optical path of the light emitted from the phosphor LED 511a.
　また、図１１に示すように、第２の光源ユニット５１２は、赤色の波長帯域（例えば、波長が６２０～６８０ｎｍ）の光を射出する赤色ＬＥＤである。ダイクロイックミラー５３１は、第１の光源ユニット５１１から射出された光の光路と第２の光源ユニット５１２から射出された光の光路とを合成する。ダイクロイックミラー５３１で光路が合成された光は、照射光Ｌとして光源装置２０５から射出される。 Further, as shown in FIG. 11, the second light source unit 512 is a red LED that emits light in a red wavelength band (for example, a wavelength of 620 to 680 nm). The dichroic mirror 531 combines the optical path of the light emitted from the first light source unit 511 and the optical path of the light emitted from the second light source unit 512. The light whose optical path is synthesized by the dichroic mirror 531 is emitted from the light source device 205 as irradiation light L.
　図１２は、図４と同様の図であり、各観察モードにおいて、光源装置２０５から射出される照射光Ｌの分光強度分布を示している。 FIG. 12 is a view similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 205 in each observation mode.
　電子内視鏡システム１が通常観察モードである場合、青色蛍光体５１１ｂが光路上に挿入された上で、第１、第２の光源ユニット５１１、５１２が発光駆動される。 When the electronic endoscope system 1 is in the normal observation mode, the first and second light source units 511 and 512 are driven to emit light after the blue phosphor 511b is inserted in the optical path.
　第１の光源ユニット５１１から射出される光の分光強度分布Ｄ５１１は、波長約４１５ｎｍ、約４７０ｎｍ、約５５０ｎｍにピークを有している。この３つの波長はそれぞれ、紫色ＬＥＤから射出される紫色ＬＥＤ光、青色蛍光体５１１ｂが発する蛍光、緑色蛍光体が発する蛍光のピーク波長である。第２の光源ユニット５１２から射出される光の分光強度分布Ｄ５１２は、波長約６５０ｎｍをピーク波長とする強度分布を有している。 The spectral intensity distribution D511 of light emitted from the first light source unit 511 has peaks at wavelengths of about 415 nm, about 470 nm, and about 550 nm. These three wavelengths are respectively the peak wavelengths of the purple LED light emitted from the purple LED, the fluorescence emitted from the blue phosphor 511b, and the fluorescence emitted from the green phosphor. The spectral intensity distribution D512 of light emitted from the second light source unit 512 has an intensity distribution with a wavelength of about 650 nm as a peak wavelength.
　また、図１２（ａ）には、ダイクロイックミラー５３１のカットオフ波長λ５３１が点線で示されている。カットオフ波長λ５３１は６２０ｎｍである。ダイクロイックミラー５３１は、カットオフ波長よりも短い波長帯域の光を透過させ、カットオフ波長以上の波長帯域の光を反射する。このダイクロイックミラー５３１により、第１の光源ユニット５１１及び第２の光源ユニット５１２から射出された光の光路が合成され、照射光Ｌとして射出される。この照射光Ｌ（通常光）を被写体に照射することにより、通常のカラー撮影画像を得ることができる。 In FIG. 12A, the cutoff wavelength λ 531 of the dichroic mirror 531 is indicated by a dotted line. The cutoff wavelength λ531 is 620 nm. The dichroic mirror 531 transmits light in a wavelength band shorter than the cutoff wavelength, and reflects light in a wavelength band equal to or greater than the cutoff wavelength. By this dichroic mirror 531, the optical paths of the light emitted from the first light source unit 511 and the second light source unit 512 are combined and emitted as irradiation light L. By irradiating the subject with the irradiation light L (normal light), a normal color photographed image can be obtained.
　また、電子内視鏡システム１が特殊観察モードである場合、青色蛍光体５１１ｂが光路上から抜去された上で、第１の光源ユニット５１１のみが発光駆動され、第２の光源ユニット５１２は発光駆動されない。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の光の比率が相対的に高くなり（すなわち狭帯域光となり）、表層血管が強調された撮影画像を得ることができる。 When the electronic endoscope system 1 is in the special observation mode, the blue phosphor 511b is removed from the optical path, and only the first light source unit 511 is driven to emit light, and the second light source unit 512 emits light. Not driven. As a result, the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained. Obtainable.
　なお、第５の実施形態では、第１の光源ユニット５１１の緑色蛍光体は、紫色ＬＥＤの発光面上に取り付けられているが、本発明はこれに限定されない。例えば、第１の光源ユニット５１１の緑色蛍光体は、紫色ＬＥＤから射出される光の光路上に挿抜可能に配置されていてもよい。この場合、電子内視鏡システム１が特殊観察モードであるとき、緑色蛍光体を光路上に挿入又は抜去することにより、被写体に照射する照射光Ｌの分光強度特性を変更することができる。 In the fifth embodiment, the green phosphor of the first light source unit 511 is mounted on the light emitting surface of the purple LED, but the present invention is not limited to this. For example, the green phosphor of the first light source unit 511 may be disposed so as to be insertable / removable on the optical path of the light emitted from the purple LED. In this case, when the electronic endoscope system 1 is in the special observation mode, the spectral intensity characteristic of the irradiation light L irradiated to the subject can be changed by inserting or removing the green phosphor on the optical path.
（第６の実施形態）
　次に、本発明の第６の実施形態にかかる内視鏡用光源装置について説明する。第６の実施形態にかかる光源装置も、第１の実施形態にかかる光源装置２０１と同様に、電子内視鏡システム１において使用される。 (Sixth embodiment)
Next, an endoscope light source device according to a sixth embodiment of the present invention will be described. The light source device according to the sixth embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
　図１３は、第６の実施形態に係る光源装置２０６のうち、光源ユニットおよびダイクロイックミラーのみを概念的に示したブロック図である。光源装置２０６は、第１の光源ユニット６１１、第２の光源ユニット６１２、第１のダイクロイックミラー６３１を備えている。各光源ユニット６１１、６１２はそれぞれ、図示省略された第１、第２光源駆動回路によって個別に発光制御される。 FIG. 13 is a block diagram conceptually showing only the light source unit and the dichroic mirror in the light source device 206 according to the sixth embodiment. The light source device 206 includes a first light source unit 611, a second light source unit 612, and a first dichroic mirror 631. The light source units 611 and 612 are individually controlled to emit light by first and second light source driving circuits (not shown).
　図１３に示すように、第１の光源ユニット６１１は、蛍光体ＬＥＤ６１１ａと赤色蛍光体６１１ｂとを有している。蛍光体ＬＥＤ６１１ａは、青色の波長帯域（例えば、波長が４３０～４９０ｎｍ）の光を射出する青色ＬＥＤと、この青色ＬＥＤの発光面上に取り付けられた緑色蛍光体とを有している。緑色蛍光体は、青色ＬＥＤから射出された青色ＬＥＤ光によって励起され、緑色の波長帯域（例えば、波長が５１０～６３０ｎｍ）の蛍光を発する。赤色蛍光体６１１ｂは、青色ＬＥＤから射出された青色ＬＥＤ光によって励起され、赤色の波長帯域（例えば、波長が５５０～７５０ｎｍ）の蛍光を発する。赤色蛍光体６１１ｂは、不図示の蛍光体挿抜機構により、蛍光体ＬＥＤ６１１ａから射出される光の光路に対して挿抜可能に支持されている。 As shown in FIG. 13, the first light source unit 611 has a phosphor LED 611a and a red phosphor 611b. The phosphor LED 611a includes a blue LED that emits light in a blue wavelength band (for example, a wavelength of 430 to 490 nm), and a green phosphor attached on the light emitting surface of the blue LED. The green phosphor is excited by blue LED light emitted from the blue LED, and emits fluorescence in a green wavelength band (for example, a wavelength of 510 to 630 nm). The red phosphor 611b is excited by the blue LED light emitted from the blue LED, and emits fluorescence in the red wavelength band (for example, the wavelength is 550 to 750 nm). The red phosphor 611b is supported by an unillustrated phosphor insertion / extraction mechanism so as to be insertable / removable with respect to the optical path of light emitted from the phosphor LED 611a.
　また、図１３に示すように、第２の光源ユニット６１２は、紫色の波長帯域（例えば、波長が３９５～４３５ｎｍ）の光を射出する紫色ＬＥＤである。ダイクロイックミラー６３１は、第１の光源ユニット６１１から射出された光の光路と第２の光源ユニット６１２から射出された光の光路とを合成する。ダイクロイックミラー６３１で光路が合成された光は、照射光Ｌとして光源装置２０６から射出される。 As shown in FIG. 13, the second light source unit 612 is a purple LED that emits light in a purple wavelength band (for example, a wavelength of 395 to 435 nm). The dichroic mirror 631 combines the optical path of the light emitted from the first light source unit 611 and the optical path of the light emitted from the second light source unit 612. The light whose optical path is synthesized by the dichroic mirror 631 is emitted from the light source device 206 as irradiation light L.
　図１４は、図４と同様の図であり、各観察モードにおいて、光源装置２０６から射出される照射光Ｌの分光強度分布を示している。 FIG. 14 is a view similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 206 in each observation mode.
　電子内視鏡システム１が通常観察モードである場合、赤色蛍光体６１１ｂが光路上に挿入された上で、第１、第２の光源ユニット６１１、６１２が発光駆動される。 When the electronic endoscope system 1 is in the normal observation mode, the first and second light source units 611 and 612 are driven to emit light after the red phosphor 611b is inserted in the optical path.
　第１の光源ユニット６１１から射出される光の分光強度分布Ｄ６１１は、波長約４６０ｎｍ、約５５０ｎｍ、約６５０ｎｍにピークを有している。この３つの波長はそれぞれ、蛍光体ＬＥＤ６１１ａから射出される青色ＬＥＤ光と緑色の蛍光、赤色蛍光体６１１ｂが発する蛍光の分光強度分布のピークである。第２の光源ユニット６１２から射出される光の分光強度分布Ｄ６１２は、約４１５ｎｍをピークとする強度分布を有している。 The spectral intensity distribution D611 of light emitted from the first light source unit 611 has peaks at wavelengths of about 460 nm, about 550 nm, and about 650 nm. These three wavelengths are the peaks of the spectral intensity distribution of the blue LED light emitted from the phosphor LED 611a, the green fluorescence, and the fluorescence emitted by the red phosphor 611b, respectively. The spectral intensity distribution D612 of light emitted from the second light source unit 612 has an intensity distribution having a peak at about 415 nm.
　また、図１４（ａ）には、ダイクロイックミラー６３１のカットオフ波長λ６３１が点線で示されている。カットオフ波長λ６３１は４４０ｎｍである。ダイクロイックミラー６３１は、カットオフ波長よりも短い波長帯域の光を透過させ、カットオフ波長以上の波長帯域の光を反射する。このダイクロイックミラー６３１により、第１の光源ユニット６１１及び第２の光源ユニット６１２から射出された光の光路が合成され、照射光Ｌとして射出される。この照射光Ｌ（通常光）を被写体に照射することにより、通常のカラー撮影画像を得ることができる。 Further, in FIG. 14A, the cutoff wavelength λ631 of the dichroic mirror 631 is indicated by a dotted line. The cutoff wavelength λ631 is 440 nm. The dichroic mirror 631 transmits light having a wavelength band shorter than the cutoff wavelength, and reflects light having a wavelength band equal to or greater than the cutoff wavelength. By the dichroic mirror 631, the optical paths of the light emitted from the first light source unit 611 and the second light source unit 612 are combined and emitted as the irradiation light L. By irradiating the subject with the irradiation light L (normal light), a normal color photographed image can be obtained.
　また、電子内視鏡システム１が特殊観察モードである場合、赤色蛍光体６１１ｂが光路上から抜去された上で、第１及び第２の光源ユニット６１１、６１２が発光駆動される。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の光の比率が相対的に高くなり（すなわち狭帯域光となり）、表層血管が強調された撮影画像を得ることができる。 Further, when the electronic endoscope system 1 is in the special observation mode, the first and second light source units 611 and 612 are driven to emit light after the red phosphor 611b is removed from the optical path. As a result, the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained. Obtainable.
（第７の実施形態）
　次に、本発明の第７の実施形態にかかる内視鏡用光源装置について説明する。第７の実施形態にかかる光源装置も、第１の実施形態にかかる光源装置２０１と同様に、電子内視鏡システム１において使用される。 (Seventh embodiment)
Next, an endoscope light source device according to a seventh embodiment of the present invention will be described. The light source device according to the seventh embodiment is also used in the electronic endoscope system 1 in the same manner as the light source device 201 according to the first embodiment.
　図１５は、第７の実施形態に係る光源装置２０７のうち、光源ユニットのみを概念的に示したブロック図である。光源装置２０７は、光源ユニット７１１を備えている。光源ユニット７１１は、図示省略された光源駆動回路によって発光制御される。 FIG. 15 is a block diagram conceptually showing only the light source unit in the light source device 207 according to the seventh embodiment. The light source device 207 includes a light source unit 711. The light source unit 711 is controlled to emit light by a light source driving circuit (not shown).
　図１５に示すように、光源ユニット７１１は、蛍光体ＬＥＤ７１１ａ、青色蛍光体７１１ｂ、赤色蛍光体７１１ｃを有している。蛍光体ＬＥＤ７１１ａは、紫色の波長帯域（例えば、波長が３９５～４３５ｎｍ）の光を射出する紫色ＬＥＤと、紫色ＬＥＤの発光面上に取り付けられた緑色蛍光体とを有している。この緑色蛍光体は、紫色ＬＥＤから射出された紫色ＬＥＤ光によって励起され、緑色の波長帯域（例えば、波長が５１０～６３０ｎｍ）の蛍光を発する。 As shown in FIG. 15, the light source unit 711 includes a phosphor LED 711a, a blue phosphor 711b, and a red phosphor 711c. The phosphor LED 711a includes a purple LED that emits light in a purple wavelength band (for example, a wavelength of 395 to 435 nm) and a green phosphor that is attached on the light emitting surface of the purple LED. This green phosphor is excited by the purple LED light emitted from the purple LED, and emits fluorescence in the green wavelength band (for example, the wavelength is 510 to 630 nm).
　青色蛍光体７１１ｂは、紫色ＬＥＤから射出された紫色ＬＥＤ光によって励起され、青色の波長帯域（例えば、波長が４３０～５５０ｎｍ）の蛍光を発する。赤色蛍光体７１１ｃは、紫色ＬＥＤから射出された紫色ＬＥＤ光によって励起され、赤色の波長帯域（例えば、波長が５５０～７５０ｎｍ）の蛍光を発する。青色蛍光体７１１ｂ及び赤色蛍光体７１１ｃは、不図示の蛍光体挿抜機構により、蛍光体ＬＥＤ７１１ａから射出される光の光路に個別に挿入又は抜去される。 The blue phosphor 711b is excited by the purple LED light emitted from the purple LED, and emits fluorescence in a blue wavelength band (for example, a wavelength of 430 to 550 nm). The red phosphor 711c is excited by the purple LED light emitted from the purple LED, and emits fluorescence in the red wavelength band (for example, the wavelength is 550 to 750 nm). The blue phosphor 711b and the red phosphor 711c are individually inserted into or removed from the optical path of light emitted from the phosphor LED 711a by a phosphor insertion / extraction mechanism (not shown).
　図１６は、図４と同様の図であり、各観察モードにおいて、光源装置２０７から射出される照射光Ｌの分光強度分布を示している。 FIG. 16 is a view similar to FIG. 4 and shows the spectral intensity distribution of the irradiation light L emitted from the light source device 207 in each observation mode.
　電子内視鏡システム１が通常観察モードである場合、青色蛍光体７１１ｂ及び赤色蛍光体７１１ｃが光路上に挿入された上で、光源ユニット７１１が発光駆動される。 When the electronic endoscope system 1 is in the normal observation mode, the light source unit 711 is driven to emit light after the blue phosphor 711b and the red phosphor 711c are inserted in the optical path.
　光源ユニット７１１から射出される光の分光強度分布Ｄ７１１は、波長約４１５ｎｍ、約４７０ｎｍ、約５５０ｎｍ、約６５０ｎｍにピークを有している。この４つの波長はそれぞれ、蛍光体ＬＥＤ７１１ａから射出される紫色ＬＥＤ光、青色蛍光体７１１ｂが発する蛍光、蛍光体ＬＥＤ７１１ａの緑色蛍光体が発する蛍光、赤色蛍光体７１１ｃが発する蛍光のピーク波長である。光源ユニット７１１から射出された光は、照射光Ｌ（通常光）として被写体に照射される。これにより、通常のカラー撮影画像を得ることができる。 The spectral intensity distribution D711 of light emitted from the light source unit 711 has peaks at wavelengths of about 415 nm, about 470 nm, about 550 nm, and about 650 nm. These four wavelengths are the peak wavelengths of the purple LED light emitted from the phosphor LED 711a, the fluorescence emitted from the blue phosphor 711b, the fluorescence emitted from the green phosphor of the phosphor LED 711a, and the fluorescence emitted from the red phosphor 711c. The light emitted from the light source unit 711 is irradiated to the subject as irradiation light L (normal light). Thereby, a normal color photographed image can be obtained.
　また、電子内視鏡システム１が特殊観察モードである場合、青色蛍光体７１１ｂ及び赤色蛍光体７１１ｃが光路上から抜去された上で、光源ユニット７１１が発光駆動される。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の光の比率が相対的に高くなり（すなわち狭帯域光となり）、表層血管が強調された撮影画像を得ることができる。 When the electronic endoscope system 1 is in the special observation mode, the light source unit 711 is driven to emit light after the blue phosphor 711b and the red phosphor 711c are removed from the optical path. As a result, the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiation light L (special light) is relatively high (that is, narrow-band light), and a captured image in which the surface blood vessels are emphasized is obtained. Obtainable.
　また、第７の実施形態の光源装置２０７は、光源ユニットの数が１つのみであるため、光源装置２０７の構成を簡素にすることができる。また、光源ユニット７１１は、赤色、青色、緑色の３つの蛍光体を有している。蛍光体は、ＬＥＤから射出される光に比べて、広い波長帯域を有している。そのため、電子内視鏡システム１が通常観察モードである場合の照射光Ｌ（通常光）の分光強度分布は、光源ユニット７１１が１つ又は２つの蛍光体を有している場合よりも、可視領域においてフラットに近づく。これにより、自然の白色光に近い照射光Ｌ（通常光）で被写体を照明することができる。 Moreover, since the light source device 207 of the seventh embodiment has only one light source unit, the configuration of the light source device 207 can be simplified. The light source unit 711 has three phosphors of red, blue, and green. The phosphor has a wider wavelength band than the light emitted from the LED. Therefore, the spectral intensity distribution of the irradiation light L (normal light) when the electronic endoscope system 1 is in the normal observation mode is more visible than when the light source unit 711 has one or two phosphors. It approaches flat in the area. Accordingly, the subject can be illuminated with the irradiation light L (normal light) close to natural white light.
　以上が本発明の例示的な実施形態の説明である。本発明の実施形態は、上記に説明したものに限定されず、本発明の技術的思想の範囲において様々な変形が可能である。例えば明細書中に例示的に明示される実施形態等又は自明な実施形態等を適宜組み合わせた内容も本発明の実施形態に含まれる。例えば、上記各実施形態では、固体発光素子としてＬＥＤを想定している。本発明はこれに限定するものではなく、ＬＤ（Laser Diode）を固体発光素子として採用することも可能である。 This completes the description of the exemplary embodiment of the present invention. Embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiment of the present invention also includes contents appropriately combined with embodiments or the like clearly shown in the specification or obvious embodiments. For example, in each of the above embodiments, an LED is assumed as the solid state light emitting device. The present invention is not limited to this, and it is also possible to employ LD (Laser Diode) as a solid state light emitting device.
　図１７は、第４の実施形態の変形例において、光源装置２０４から射出される照射光Ｌの分光強度分布を示している。本変形例では、４つの観察モード（通常観察モード、第１特殊観察モード、第２特殊観察モード、第３特殊観察モード）がある。図１７（ａ）は、通常観察モードにおける照射光Ｌ（通常光）の分光強度分布を示し、図１７（ｂ）は、第１特殊観察モードにおける照射光Ｌ（特殊光）の分光強度分布を示し、図１７（ｃ）は、第２特殊観察モードにおける照射光Ｌ（特殊光）の分光強度分布を示し、図１７（ｄ）は、第３特殊観察モードにおける照射光Ｌ（特殊光）の分光強度分布を示している。図１７に示される分光強度分布の横軸は波長（ｎｍ）を示し、縦軸は照射光Ｌの強度を示している。なお、縦軸は、強度の最大値が１となるように規格化されている。 FIG. 17 shows the spectral intensity distribution of the irradiation light L emitted from the light source device 204 in the modification of the fourth embodiment. In this modification, there are four observation modes (normal observation mode, first special observation mode, second special observation mode, and third special observation mode). FIG. 17A shows the spectral intensity distribution of the irradiation light L (normal light) in the normal observation mode, and FIG. 17B shows the spectral intensity distribution of the irradiation light L (special light) in the first special observation mode. FIG. 17C shows the spectral intensity distribution of the irradiation light L (special light) in the second special observation mode, and FIG. 17D shows the irradiation light L (special light) in the third special observation mode. The spectral intensity distribution is shown. The horizontal axis of the spectral intensity distribution shown in FIG. 17 indicates the wavelength (nm), and the vertical axis indicates the intensity of the irradiation light L. Note that the vertical axis is standardized so that the maximum intensity value is 1.
　通常観察モード時の動作は、図９及び図１０を用いて説明した第４の実施形態と同じである。そのため、通常観察モード時は、図１０（ａ）と同じ分光特性を持つ照射光Ｌ（通常光）が射出される。この照射光Ｌ（通常光）を被写体に照射することにより、通常のカラー撮影画像を得ることができる。 The operation in the normal observation mode is the same as that of the fourth embodiment described with reference to FIGS. Therefore, in the normal observation mode, irradiation light L (normal light) having the same spectral characteristics as in FIG. By irradiating the subject with the irradiation light L (normal light), a normal color photographed image can be obtained.
　電子内視鏡システム１が第１特殊観察モードである場合、青色蛍光体４１１ｂが光路上から抜去された上で、第１の光源ユニット４１１が発光駆動され、第２の光源ユニット４１２及び第３の光源ユニット４１３が発光駆動されない。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の光の比率が相対的に高くなり（すなわち波長４１５ｎｍ付近のみにピークを持つ狭帯域光となり）、主に表層血管が強調された撮影画像を得ることができる。 When the electronic endoscope system 1 is in the first special observation mode, after the blue phosphor 411b is removed from the optical path, the first light source unit 411 is driven to emit light, and the second light source unit 412 and the third light source unit 412 are driven. The light source unit 413 is not driven to emit light. As a result, the ratio of light in the vicinity of the wavelength of 415 nm, which is the absorption peak of hemoglobin, of the irradiation light L (special light) is relatively high (that is, narrowband light having a peak only in the vicinity of the wavelength of 415 nm). A captured image in which the surface blood vessels are emphasized can be obtained.
　電子内視鏡システム１が第２特殊観察モードである場合、青色蛍光体４１１ｂが光路上から抜去された上で、第２の光源ユニット４１２が発光駆動され、第１の光源ユニット４１１及び第３の光源ユニット４１３が発光駆動されない。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長５５０ｎｍ付近の光の比率が相対的に高くなり（すなわち波長５５０ｎｍ付近のみにピークを持つ狭帯域光となり）、主に中層血管が強調された撮影画像を得ることができる。 When the electronic endoscope system 1 is in the second special observation mode, after the blue phosphor 411b is removed from the optical path, the second light source unit 412 is driven to emit light, and the first light source unit 411 and the third light source unit 411b are driven. The light source unit 413 is not driven to emit light. As a result, the ratio of light in the vicinity of the wavelength of 550 nm, which is the absorption peak of hemoglobin, of the irradiation light L (special light) is relatively high (that is, the light is narrowband having a peak only in the vicinity of the wavelength of 550 nm). A captured image in which the middle layer blood vessel is emphasized can be obtained.
　電子内視鏡システム１が第３特殊観察モードである場合、青色蛍光体４１１ｂが光路上から抜去された上で、第３の光源ユニット４１３が発光駆動され、第１の光源ユニット４１１及び第２の光源ユニット４１２が発光駆動されない。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長６５０ｎｍ付近の光の比率が相対的に高くなり（すなわち波長６５０ｎｍ付近のみにピークを持つ狭帯域光となり）、主に深層血管が強調された撮影画像を得ることができる。 When the electronic endoscope system 1 is in the third special observation mode, after the blue phosphor 411b is removed from the optical path, the third light source unit 413 is driven to emit light, and the first light source unit 411 and the second light source unit 411 are driven. The light source unit 412 is not driven to emit light. As a result, the ratio of light in the vicinity of the wavelength of 650 nm, which is the peak of the absorbance of hemoglobin, in the irradiated light L (special light) is relatively high (that is, narrowband light having a peak only in the vicinity of the wavelength of 650 nm). A captured image in which deep blood vessels are emphasized can be obtained.
　このように、本変形例では、第１特殊観察モードにおいて、主に表層血管を強調した撮影画像を得ることができ、第２特殊観察モードにおいて、主に中層血管を強調した撮影画像を得ることができ、第３特殊観察モードにおいて、主に深層血管を強調した撮影画像を得ることができる。すなわち、本変形例では、第１～第３の各特殊観察モードを切り替えることにより、所望の層域（第１特殊観察モードでは表層、第２特殊観察モードでは中層、第３特殊観察モードでは深層）の血管を重点的に強調した画像を観察することができる。 As described above, in the present modification, it is possible to obtain a photographed image that mainly emphasizes the surface blood vessels in the first special observation mode, and obtain a photographed image that mainly emphasizes the middle-layer blood vessels in the second special observation mode. In the third special observation mode, it is possible to obtain a photographed image mainly emphasizing deep blood vessels. In other words, in the present modification, the first to third special observation modes are switched to obtain a desired layer area (surface layer in the first special observation mode, middle layer in the second special observation mode, and deep layer in the third special observation mode. ) Can be observed with emphasis on blood vessels.
　第７の実施形態では、通常観察モード時には青色蛍光体７１１ｂ及び赤色蛍光体７１１ｃが光路上に挿入され、特殊観察モード時には青色蛍光体７１１ｂ及び赤色蛍光体７１１ｃが光路から抜去される。従って、第７の実施形態では、青色蛍光体７１１ｂ及び赤色蛍光体７１１ｃが観察モードに応じて同じ挿抜動作（リンクした動き）を行っている。これに対し、第７の実施形態の変形例では、青色蛍光体７１１ｂ及び赤色蛍光体７１１ｃが観察モードに応じて同じ挿抜動作を行わず、別の挿抜動作を行う。 In the seventh embodiment, the blue phosphor 711b and the red phosphor 711c are inserted on the optical path in the normal observation mode, and the blue phosphor 711b and the red phosphor 711c are removed from the optical path in the special observation mode. Therefore, in the seventh embodiment, the blue phosphor 711b and the red phosphor 711c perform the same insertion / extraction operation (linked movement) according to the observation mode. On the other hand, in the modification of the seventh embodiment, the blue phosphor 711b and the red phosphor 711c do not perform the same insertion / extraction operation according to the observation mode, but perform another insertion / extraction operation.
　具体的には、第７の実施形態の変形例では、更に２つの特殊観察モード（第１及び第２特殊観察モード）が追加される。第１特殊観察モード時には、青色蛍光体７１１ｂが光路上から抜去された上で、蛍光体ＬＥＤ７１１ａ及び赤色蛍光体７１１ｃが発光駆動される。一方、第２特殊観察モード時には、赤色蛍光体７１１ｃが光路上から抜去された上で、蛍光体ＬＥＤ７１１ａ及び青色蛍光体７１１ｂが発光駆動される。すなわち、本変形例では、蛍光体ＬＥＤ７１１ａより射出される光によって励起される複数の蛍光体（青色蛍光体７１１ｂ、赤色蛍光体７１１ｃ）が蛍光体ＬＥＤ７１１ａの光路上に並べて配置されており、各蛍光体が観察モードに応じて別の挿抜動作（青色蛍光体７１１ｂの挿入時には赤色蛍光体７１１ｃが抜去され、赤色蛍光体７１１ｃの挿入時には青色蛍光体７１１ｂが抜去される。）を行う。 Specifically, in the modified example of the seventh embodiment, two special observation modes (first and second special observation modes) are further added. In the first special observation mode, the blue phosphor 711b is removed from the optical path, and the phosphor LED 711a and the red phosphor 711c are driven to emit light. On the other hand, in the second special observation mode, the red phosphor 711c is removed from the optical path, and the phosphor LED 711a and the blue phosphor 711b are driven to emit light. That is, in this modification, a plurality of phosphors (blue phosphor 711b, red phosphor 711c) excited by light emitted from phosphor LED 711a are arranged side by side on the optical path of phosphor LED 711a, and each fluorescence The body performs another insertion / extraction operation according to the observation mode (the red phosphor 711c is removed when the blue phosphor 711b is inserted, and the blue phosphor 711b is removed when the red phosphor 711c is inserted).
　上記の実施形態に係る電子内視鏡システムでは、特殊光（狭帯域光）を用いて血管を強調した狭帯域観察画像を生成して表示する構成が採用されているが、別の実施形態に係る電子内視鏡システムでは、波長域の異なる光で撮像した複数の画像に基づいて被写体の生体情報（具体的には酸素飽和度）を定量的に分析して画像化する構成が採用されてもよい。 In the electronic endoscope system according to the above-described embodiment, a configuration in which a narrow-band observation image in which a blood vessel is emphasized using special light (narrow-band light) is generated and displayed is employed. In such an electronic endoscope system, a configuration is adopted in which biological information (specifically, oxygen saturation) of a subject is quantitatively analyzed and imaged based on a plurality of images taken with light having different wavelength ranges. Also good.
　図１８に、別の実施形態に係る光源装置２０８のブロック図を示す。別の実施形態については、便宜上、第１の実施形態をベースに説明する。図１８に示されるように、光源装置２０８は、第１の実施形態に係る光源装置２０１に対し、第２の光源ユニット１１２を第２の光源ユニット１１２’に代えると共に回転式ターレット４００及びフィルタ回転機構４３０を追加した構成となっている。 FIG. 18 shows a block diagram of a light source device 208 according to another embodiment. Another embodiment will be described based on the first embodiment for convenience. As shown in FIG. 18, the light source device 208 is different from the light source device 201 according to the first embodiment in that the second light source unit 112 is replaced with the second light source unit 112 ′ and the rotary turret 400 and the filter are rotated. The mechanism 430 is added.
　図１９は、別の実施形態に係る光源装置２０８のうち、光源ユニット、ダイクロイックミラー及び回転式ターレットのみを概念的に示したブロック図である。第２の光源ユニット１１２’は、青色ＬＥＤ１１２ａを有しており、黄色蛍光体１１２ｂを有していない。 FIG. 19 is a block diagram conceptually showing only a light source unit, a dichroic mirror, and a rotary turret in a light source device 208 according to another embodiment. The second light source unit 112 'has a blue LED 112a and does not have a yellow phosphor 112b.
　図２０は、回転式ターレット４００の構成を示す図である。図２０に示されるように、回転式ターレット４００の中心に形成された軸受孔には、フィルタ回転機構４３０を構成するＤＣモータのモータ軸４３２が圧入されている。回転式ターレット４００は、フィルタ回転機構４３０により、モータ軸４３２周りに回転動作可能に軸支されている。なお、フィルタ回転機構４３０には周知の構成が採用されるため、フィルタ回転機構４３０に関する、ここでの詳細な説明は省略する。 FIG. 20 is a diagram showing a configuration of the rotary turret 400. As shown in FIG. 20, a motor shaft 432 of a DC motor constituting the filter rotation mechanism 430 is press-fitted into the bearing hole formed at the center of the rotary turret 400. The rotary turret 400 is supported by a filter rotating mechanism 430 so as to be rotatable around a motor shaft 432. In addition, since a well-known structure is employ | adopted for the filter rotation mechanism 430, the detailed description here regarding the filter rotation mechanism 430 is abbreviate | omitted.
　回転式ターレット４００には、４つの開口が周方向に並べて形成されている。各開口には、夫々異なる蛍光体が埋設されている。具体的には、黄色蛍光体１１２ｂ’、第１の酸素飽和度観察用蛍光体Ｆｓ１、第２の酸素飽和度観察用蛍光体Ｆｓ２、狭帯域観察用蛍光体Ｆｓ３が埋設されている。別の実施形態では、回転式ターレット４００を用いることにより、通常観察モードによる通常観察画像及び特殊観察モードによる狭帯域観察画像に加えて、酸素飽和度観察モードによる酸素飽和度分布画像を表示することが可能となっている。 The rotary turret 400 has four openings arranged in the circumferential direction. Different phosphors are embedded in the respective openings. Specifically, a yellow phosphor 112b ', a first oxygen saturation observation phosphor Fs1, a second oxygen saturation observation phosphor Fs2, and a narrow band observation phosphor Fs3 are embedded. In another embodiment, by using the rotary turret 400, in addition to the normal observation image in the normal observation mode and the narrow band observation image in the special observation mode, the oxygen saturation distribution image in the oxygen saturation observation mode is displayed. Is possible.
　ここで、ヘモグロビンの分光特性と、本実施形態における酸素飽和度の計算原理について説明する。 Here, the spectral characteristics of hemoglobin and the calculation principle of oxygen saturation in this embodiment will be described.
　図２１に、５５０ｎｍ付近のヘモグロビンの吸収スペクトルを示す。ヘモグロビンは、５５０ｎｍ付近にポルフィリンに由来するＱ帯と呼ばれる強い吸収帯を有している。ヘモグロビンの吸収スペクトルは、酸素飽和度（全ヘモグロビンのうち酸素化ヘモグロビンが占める割合）に応じて変化する。図２１における実線の波形は、酸素飽和度が１００％の場合の（すなわち、酸素化ヘモグロビンHbOの）吸収スペクトルを示し、長破線の波形は、酸素飽和度が０％の場合の（すなわち、還元ヘモグロビンHbの）吸収スペクトルを示す。また、短破線は、その中間の酸素飽和度（１０、２０、３０、・・・９０％）におけるヘモグロビン（酸素化ヘモグロビンと還元ヘモグロビンの混合物）の吸収スペクトルを示す。 FIG. 21 shows an absorption spectrum of hemoglobin near 550 nm. Hemoglobin has a strong absorption band called a Q band derived from porphyrin near 550 nm. The absorption spectrum of hemoglobin varies depending on the oxygen saturation (the ratio of oxygenated hemoglobin in the total hemoglobin). The solid line waveform in FIG. 21 shows an absorption spectrum when the oxygen saturation is 100% (that is, oxygenated hemoglobin HbO), and the long broken line waveform is when the oxygen saturation is 0% (that is, reduction). The absorption spectrum of hemoglobin Hb is shown. The short dashed line shows the absorption spectrum of hemoglobin (a mixture of oxygenated hemoglobin and reduced hemoglobin) at intermediate oxygen saturation (10, 20, 30,... 90%).
　図２１に示されるように、Ｑ帯において、酸素化ヘモグロビンと還元ヘモグロビンは互いに異なるピーク波長を有している。具体的には、酸素化ヘモグロビンは、波長５４２ｎｍ付近に吸収ピークＰ１を有しており、波長５７８ｎｍ付近に吸収ピークＰ３を有している。一方、還元ヘモグロビンは、５５８ｎｍ付近に吸収ピークＰ２を有している。図２１は、各成分（酸素化ヘモグロビン、還元ヘモグロビン）の濃度の和が一定となる２成分系の吸収スペクトルであるため、各成分の濃度（すなわち酸素飽和度）によらず吸収が一定となる等吸収点Ｅ１、Ｅ２、Ｅ３、Ｅ４が現れる。 As shown in FIG. 21, in the Q band, oxygenated hemoglobin and reduced hemoglobin have different peak wavelengths. Specifically, oxygenated hemoglobin has an absorption peak P1 near a wavelength of 542 nm and an absorption peak P3 near a wavelength of 578 nm. On the other hand, reduced hemoglobin has an absorption peak P2 near 558 nm. FIG. 21 is a two-component absorption spectrum in which the sum of the concentrations of the components (oxygenated hemoglobin and deoxyhemoglobin) is constant. Therefore, the absorption is constant regardless of the concentration of each component (that is, oxygen saturation). Iso-absorption points E1, E2, E3, E4 appear.
　以下の説明では、等吸収点Ｅ１とＥ２とで挟まれた波長領域を「波長域Ｒ１」と記し、等吸収点Ｅ２とＥ３とで挟まれた波長領域を「波長域Ｒ２」と記し、等吸収点Ｅ３とＥ４とで挟まれた波長領域を「波長域Ｒ３」と記す。また、等吸収点Ｅ１とＥ４とで挟まれた波長領域（すなわち波長域Ｒ１、Ｒ２及びＲ３を合わせたもの）を「波長域Ｒ０」と記す。 In the following description, the wavelength region sandwiched between the equal absorption points E1 and E2 is referred to as “wavelength region R1”, the wavelength region sandwiched between the equal absorption points E2 and E3 is referred to as “wavelength region R2”, and so on. A wavelength region sandwiched between the absorption points E3 and E4 is referred to as a “wavelength region R3”. A wavelength region sandwiched between the isosbestic points E1 and E4 (that is, a combination of the wavelength regions R1, R2, and R3) is referred to as a “wavelength region R0”.
　なお、波長域Ｒ０は、５２８ｎｍ～５８４ｎｍである。波長域Ｒ２は、５４６ｎｍ～５７０ｎｍである。 The wavelength range R0 is 528 nm to 584 nm. The wavelength range R2 is 546 nm to 570 nm.
　図２１に示されるように、隣接する等吸収点間では、酸素飽和度に対して吸収が単調に増加又は減少する。また、隣接する等吸収点間では、ヘモグロビンの吸収は、酸素飽和度に対してほぼ線形的に変化する。 21. As shown in FIG. 21, the absorption monotonously increases or decreases with respect to the oxygen saturation between adjacent isosbestic points. Further, between adjacent isosbestic points, the absorption of hemoglobin changes almost linearly with respect to the oxygen saturation.
　具体的には、波長域Ｒ１、Ｒ３におけるヘモグロビンの吸収ＡＲ１、ＡＲ３は酸素化ヘモグロビンの濃度（酸素飽和度）に対して線形的に単調増加し、波長域Ｒ２におけるヘモグロビンの吸収ＡＲ２は還元ヘモグロビンの濃度（１－酸素飽和度）に対して線形的に単調増加する。従って、次式（１）により定義される指標Ｘは、酸素化ヘモグロビンの濃度（酸素飽和度）に対して線形的に単調増加する。
（式１）
Ｘ＝（ＡＲ１＋ＡＲ３）－ＡＲ２ Specifically, the absorption A R1, A R3 of hemoglobin in the wavelength range R1, R3 is linearly and monotonously increases with respect to the concentration of oxygenated hemoglobin (oxygen saturation), absorption A R2 of hemoglobin in the wavelength range R2 is It increases monotonically linearly with the concentration of reduced hemoglobin (1-oxygen saturation). Therefore, the index X defined by the following equation (1) increases linearly and monotonously with respect to the oxygenated hemoglobin concentration (oxygen saturation).
(Formula 1)
X = (A R1 + A R3 ) −A R2
　従って、予め実験的に酸素飽和度と指標Ｘとの定量的な関係を取得すれば、指標Ｘの値から酸素飽和度を計算することができる。 Therefore, if a quantitative relationship between the oxygen saturation and the index X is experimentally obtained in advance, the oxygen saturation can be calculated from the value of the index X.
　第１の酸素飽和度観察用蛍光体Ｆｓ１は、青色ＬＥＤ１１２ａより射出される光によって励起される蛍光体であり、５５０ｎｍ帯の蛍光を発する。図２１に示されるように、第１の酸素飽和度観察用蛍光体Ｆｓ１は、等吸収点Ｅ１からＥ４までの波長域（すなわち、波長域Ｒ０）の蛍光を発し、それ以外の波長領域の蛍光を発しない。第２の酸素飽和度観察用蛍光体Ｆｓ２は、青色ＬＥＤ１１２ａより射出される光によって励起される蛍光体であり、等吸収点Ｅ２からＥ３までの波長域（すなわち、波長域Ｒ２）の蛍光を発し、それ以外の波長領域の蛍光を発しない。 The first oxygen saturation observation phosphor Fs1 is a phosphor excited by light emitted from the blue LED 112a and emits fluorescence in the 550 nm band. As shown in FIG. 21, the first oxygen saturation observation phosphor Fs1 emits fluorescence in the wavelength region (that is, wavelength region R0) from the isosbestic points E1 to E4, and the fluorescence in other wavelength regions. Does not emit. The second oxygen saturation observation phosphor Fs2 is a phosphor excited by light emitted from the blue LED 112a, and emits fluorescence in a wavelength region from the isoabsorption points E2 to E3 (that is, the wavelength region R2). , Does not emit fluorescence in other wavelength regions.
　黄色蛍光体１１２ｂ’は、青色ＬＥＤ１１２ａより射出される光によって励起される蛍光体であり、黄色蛍光体１１２ｂと同じ蛍光を発する。狭帯域観察用蛍光体Ｆｓ３は、特定の生体組織（主に深層血管）に対して吸光度の高い６５０ｎｍ帯（６３０～６５０ｎｍ）の蛍光を発し、それ以外の波長領域の蛍光を発しない。 The yellow phosphor 112b 'is a phosphor excited by light emitted from the blue LED 112a and emits the same fluorescence as the yellow phosphor 112b. The narrow-band observation phosphor Fs3 emits fluorescence in a 650 nm band (630 to 650 nm) having high absorbance with respect to a specific biological tissue (mainly deep blood vessels) and does not emit fluorescence in other wavelength regions.
　なお、別の実施形態では、青色ＬＥＤ１１２ａに代えて、他色のＬＥＤ（紫色ＬＥＤや緑色ＬＥＤ等）が備えられてもよい。この場合、第１の酸素飽和度観察用蛍光体Ｆｓ１は、上記の他色のＬＥＤより射出される光によって波長域Ｒ０の蛍光を発する。第２の酸素飽和度観察用蛍光体Ｆｓ２は、上記の他色のＬＥＤより射出される光によって波長域Ｒ２の蛍光を発する。黄色蛍光体１１２ｂ’は、上記の他色のＬＥＤより射出される光によって黄色蛍光体１１２ｂと同じ蛍光を発する。 In another embodiment, instead of the blue LED 112a, another color LED (such as a purple LED or a green LED) may be provided. In this case, the first oxygen saturation observation phosphor Fs1 emits fluorescence in the wavelength region R0 by the light emitted from the other color LEDs. The second phosphor Ss for observing the degree of oxygen saturation Fs2 emits fluorescence in the wavelength region R2 by the light emitted from the other color LED. The yellow phosphor 112b 'emits the same fluorescence as the yellow phosphor 112b by the light emitted from the other color LEDs.
　このように、回転式ターレット４００には、夫々異なる発光特性を持つ蛍光体が複数（黄色蛍光体１１２ｂ’、第１の酸素飽和度観察用蛍光体Ｆｓ１、第２の酸素飽和度観察用蛍光体Ｆｓ２、狭帯域観察用蛍光体Ｆｓ３）配置されている。 As described above, the rotary turret 400 includes a plurality of phosphors having different emission characteristics (the yellow phosphor 112b ′, the first oxygen saturation observation phosphor Fs1, the second oxygen saturation observation phosphor). Fs2, narrowband observation phosphor Fs3) are arranged.
　通常観察モード時は、青色蛍光体１１１ｂが光路上に挿入された上で、第１の光源ユニット１１１及び第２の光源ユニット１１２’が発光駆動されると共に、黄色蛍光体１１２ｂ’が照射光Ｌの光路上に位置する状態で回転式ターレット４００が停止する。そのため、通常観察モード時は、第１の実施形態と同じ分光特性（図４（ａ）参照）を持つ照射光Ｌ（通常光）が射出される。この照射光Ｌ（通常光）を被写体に照射することにより、通常のカラー撮影画像を得ることができる。 In the normal observation mode, the blue phosphor 111b is inserted in the optical path, the first light source unit 111 and the second light source unit 112 ′ are driven to emit light, and the yellow phosphor 112b ′ is irradiated with the irradiation light L. The rotary turret 400 stops in a state where it is located on the optical path. Therefore, in the normal observation mode, the irradiation light L (normal light) having the same spectral characteristics (see FIG. 4A) as in the first embodiment is emitted. By irradiating the subject with the irradiation light L (normal light), a normal color photographed image can be obtained.
　特殊観察モード時は、青色蛍光体１１１ｂが光路から抜去された上で、第１の光源ユニット１１１及び第２の光源ユニット１１２’が発光駆動されると共に、黄色蛍光体１１２ｂ’が照射光Ｌの光路上に位置する状態で回転式ターレット４００が停止する。そのため、特殊観察モード時も、第１の実施形態と同じ分光特性（図４（ｂ）参照）を持つ照射光Ｌ（通常光）が射出される。これにより、照射光Ｌ（特殊光）のうち、ヘモグロビンの吸光度のピークとなる波長４１５ｎｍ付近の光の比率が相対的に高くなり（すなわち狭帯域光となり）、主に表層血管が強調された撮影画像を得ることができる。 In the special observation mode, after the blue phosphor 111b is removed from the optical path, the first light source unit 111 and the second light source unit 112 ′ are driven to emit light, and the yellow phosphor 112b ′ is irradiated with the irradiation light L. The rotary turret 400 stops in a state where it is located on the optical path. Therefore, even in the special observation mode, the irradiation light L (normal light) having the same spectral characteristics (see FIG. 4B) as in the first embodiment is emitted. As a result, the ratio of light in the vicinity of a wavelength of 415 nm, which is the peak of the absorbance of hemoglobin, in the irradiated light L (special light) is relatively high (that is, narrow-band light), and imaging in which mainly the surface blood vessels are emphasized An image can be obtained.
　酸素飽和度観察モード時は、青色蛍光体１１１ｂが光路から抜去された上で、第１の光源ユニット１１１及び第２の光源ユニット１１２’が発光駆動されると共に、黄色蛍光体１１２ｂ’、第１の酸素飽和度観察用蛍光体Ｆｓ１、第２の酸素飽和度観察用蛍光体Ｆｓ２、狭帯域観察用蛍光体Ｆｓ３の各蛍光体が照射光Ｌの光路上にフレームレートと同期（撮像周期と同期）したタイミングで順次挿入されるように、フィルタ回転機構４３０により、４フレームで一回転する周期で回転式ターレット４００が回転駆動される。なお、酸素飽和度観察モード時において、第１の光源ユニット１１１は発光駆動されなくてもよい。 In the oxygen saturation observation mode, after the blue phosphor 111b is removed from the optical path, the first light source unit 111 and the second light source unit 112 ′ are driven to emit light, and the yellow phosphor 112b ′ and the first phosphor Each of the phosphors for oxygen saturation observation Fs1, the second oxygen saturation observation phosphor Fs2, and the narrowband observation phosphor Fs3 is synchronized with the frame rate on the optical path of the irradiation light L (synchronized with the imaging period). ), The rotary turret 400 is rotationally driven by the filter rotating mechanism 430 at a period of one rotation in four frames. In the oxygen saturation observation mode, the first light source unit 111 may not be driven to emit light.
　回転式ターレット４００には、貫通孔４０２が形成されている。システムコントローラ２１は、フィルタ回転機構４３０を構成するフォトインタラプタ４３４による貫通孔４０２の検出タイミングに基づいて回転式ターレット４００の回転位相を検知して調整する。これにより、回転式ターレット４００は、酸素飽和度観察モード中、一定速度（４フレームで一回転する周期）で回転駆動する。 A through hole 402 is formed in the rotary turret 400. The system controller 21 detects and adjusts the rotational phase of the rotary turret 400 based on the detection timing of the through hole 402 by the photo interrupter 434 constituting the filter rotating mechanism 430. Thereby, the rotary turret 400 is rotationally driven at a constant speed (a period of one rotation in four frames) during the oxygen saturation observation mode.
　これにより、被写体には、黄色蛍光体１１２ｂ’、第１の酸素飽和度観察用蛍光体Ｆｓ１、第２の酸素飽和度観察用蛍光体Ｆｓ２、狭帯域観察用蛍光体Ｆｓ３の各蛍光体に応じた照射光Ｌ（蛍光）が順次照射される。そのため、後段信号処理回路２８には、黄色蛍光体１１２ｂ’、第１の酸素飽和度観察用蛍光体Ｆｓ１、第２の酸素飽和度観察用蛍光体Ｆｓ２、狭帯域観察用蛍光体Ｆｓ３の各蛍光体を介した照射光Ｌに対応する画像信号が順次入力される。 Accordingly, the subject corresponds to each phosphor of the yellow phosphor 112b ′, the first oxygen saturation observation phosphor Fs1, the second oxygen saturation observation phosphor Fs2, and the narrow band observation phosphor Fs3. The irradiated light L (fluorescence) is sequentially irradiated. Therefore, the post-stage signal processing circuit 28 includes each of the yellow phosphor 112b ′, the first oxygen saturation observation phosphor Fs1, the second oxygen saturation observation phosphor Fs2, and the narrow band observation phosphor Fs3. Image signals corresponding to the irradiation light L through the body are sequentially input.
　後段信号処理回路２８は、上記式（１）を用いて、画像メモリ２７より入力される第１の酸素飽和度観察用蛍光体Ｆｓ１に対応する画像信号及び第２の酸素飽和度観察用蛍光体Ｆｓ２に対応する画像信号から指標Ｘを計算する。 The post-stage signal processing circuit 28 uses the above equation (1) to output the image signal corresponding to the first oxygen saturation observation phosphor Fs1 input from the image memory 27 and the second oxygen saturation observation phosphor. An index X is calculated from the image signal corresponding to Fs2.
　後段信号処理回路２８が備える不揮発性メモリ（不図示）には、予め実験的に取得されたヘモグロビンの酸素飽和度と指標Ｘの値との定量的関係を示す数値表が記憶されている。後段信号処理回路２８は、この数値表を参照して、上記式（１）を用いて算出された指標Ｘの値に対応する酸素飽和度ＳａｔＯ２（ｘ，ｙ）を取得する。後段信号処理回路２８は、取得された酸素飽和度ＳａｔＯ２（ｘ，ｙ）に所定の定数を乗じた値を各画素（ｘ，ｙ）の画素値とする画像データ（酸素飽和度分布画像データ）を生成する。 A non-volatile memory (not shown) provided in the post-stage signal processing circuit 28 stores a numerical table showing a quantitative relationship between the oxygen saturation of hemoglobin and the value of the index X, which are experimentally acquired in advance. The post-stage signal processing circuit 28 refers to this numerical table and obtains the oxygen saturation SatO 2 (x, y) corresponding to the value of the index X calculated using the above equation (1). The post-stage signal processing circuit 28 uses the data obtained by multiplying the acquired oxygen saturation SatO 2 (x, y) by a predetermined constant as the pixel value of each pixel (x, y) (oxygen saturation distribution image data). ) Is generated.
　また、後段信号処理回路２８は、画像メモリ２７より入力される狭帯域観察用蛍光体Ｆｓ３に対応する画像信号を用いて狭帯域観察画像データを生成する。 The post-stage signal processing circuit 28 generates narrowband observation image data using an image signal corresponding to the narrowband observation phosphor Fs3 input from the image memory 27.
　後段信号処理回路２８は、酸素飽和度分布画像データを所定のビデオフォーマット信号に変換する。変換されたビデオフォーマット信号は、モニタ３００に出力される。これにより、酸素飽和度分布画像がモニタ３００の表示画面に表示される。 The post-stage signal processing circuit 28 converts the oxygen saturation distribution image data into a predetermined video format signal. The converted video format signal is output to the monitor 300. Thereby, the oxygen saturation distribution image is displayed on the display screen of the monitor 300.
　別の実施形態では、光学フィルタ等の減光手段を用いることなく、酸素飽和度分布画像が得られる。そのため、光利用効率が減光手段を用いる場合と比べて高い。 In another embodiment, an oxygen saturation distribution image can be obtained without using a dimming means such as an optical filter. For this reason, the light use efficiency is higher than that in the case where the light reducing means is used.
　後段信号処理回路２８は、酸素飽和度分布画像データに加えて狭帯域観察画像データを所定のビデオフォーマット信号に変換してもよい。この場合、酸素飽和度分布画像に加えて狭帯域観察画像がモニタ３００の表示画面に表示される。 The post-stage signal processing circuit 28 may convert the narrowband observation image data into a predetermined video format signal in addition to the oxygen saturation distribution image data. In this case, a narrow-band observation image is displayed on the display screen of the monitor 300 in addition to the oxygen saturation distribution image.
　なお、酸素飽和度を定量的に分析して画像化する技術については、例えば国際公開第２０１４／１９２７８１号パンフレットに、より具体的な例示が開示されている。 Note that more specific examples of the technique for quantitatively analyzing and imaging oxygen saturation are disclosed in, for example, International Publication No. 2014/192781.

Claims (8)

  1. 　第１の波長帯域の光を射出する第１の固体発光素子と、該第１の波長帯域の光によって励起され、第１の蛍光を発する第１の蛍光体と、を有する第１の光源ユニットと、
    　前記第１の蛍光体を前記第１の固体発光素子から射出される光の光路に対して挿抜可能に支持する蛍光体挿抜手段と、
    を備え、
    　前記蛍光体挿抜手段により前記第１の蛍光体が前記第１の固体発光素子から射出される光の光路に挿入されると、前記第１の光源ユニットから該第１の波長帯域の光と前記第１の蛍光とが同一の光路で射出されて内視鏡に供給され、
    　前記蛍光体挿抜手段により前記第１の蛍光体が前記第１の固体発光素子から射出される光の光路から抜去されると、前記第１の光源ユニットから該第１の波長帯域の光が射出されて前記内視鏡に供給される、
    内視鏡用光源装置。     A first light source unit comprising: a first solid-state light emitting element that emits light of a first wavelength band; and a first phosphor that is excited by light of the first wavelength band and emits first fluorescence. When,
    Phosphor inserting / extracting means for supporting the first phosphor so as to be insertable / removable with respect to an optical path of light emitted from the first solid state light emitting device;
    With
    When the first phosphor is inserted into the optical path of the light emitted from the first solid state light emitting device by the phosphor insertion / extraction means, the light of the first wavelength band and the light from the first light source unit The first fluorescence is emitted in the same optical path and supplied to the endoscope;
    When the first phosphor is removed from the optical path of the light emitted from the first solid state light emitting device by the phosphor inserting / extracting means, the light in the first wavelength band is emitted from the first light source unit. Being supplied to the endoscope,
    Endoscope light source device.
  2. 　前記第１の蛍光の波長帯域のピーク波長とは異なるピーク波長をもつ波長帯域の光を射出する第２の光源ユニットと、
    　前記第１の光源ユニットから射出される光の光路と前記第２の光源ユニットから射出される光の光路とを合成し、光路を合成した光を前記内視鏡に供給する第１の光路合成手段と、
    を更に備える、
    請求項１に記載の内視鏡用光源装置。     A second light source unit that emits light in a wavelength band having a peak wavelength different from a peak wavelength of the wavelength band of the first fluorescence;
    A first optical path synthesis that combines an optical path of light emitted from the first light source unit and an optical path of light emitted from the second light source unit, and supplies the combined light to the endoscope. Means,
    Further comprising
    The endoscope light source device according to claim 1.
  3. 　前記第２の光源ユニットは、
    　　第２の固体発光素子と、該第２の固体発光素子から射出された光によって励起され、第２の蛍光を発する第２の蛍光体と、を有し、
    　前記第２の蛍光の波長帯域のピーク波長は、
    　　前記第１の波長帯域のピーク波長及び前記第１の蛍光の波長帯域のピーク波長とは異なる、
    請求項２に記載の内視鏡用光源装置。     The second light source unit is
    A second solid state light emitting device, and a second phosphor that is excited by light emitted from the second solid state light emitting device and emits second fluorescence,
    The peak wavelength of the wavelength band of the second fluorescence is
    The peak wavelength of the first wavelength band is different from the peak wavelength of the wavelength band of the first fluorescence.
    The endoscope light source device according to claim 2.
  4. 　前記第１の光源ユニットから射出される光のピーク波長及び前記第２の光源ユニットから射出される光のピーク波長とは異なるピーク波長をもつ第３の波長帯域の光を射出する第３の光源ユニットと、
    　前記第１の光路合成手段によって合成された光の光路と、前記第３の光源ユニットから射出された光の光路とを合成し、光路を合成した光を前記内視鏡に供給する第２の光路合成手段と、
    を更に備える、
    請求項２又は請求項３に記載の内視鏡用光源装置。     A third light source that emits light in a third wavelength band having a peak wavelength different from the peak wavelength of the light emitted from the first light source unit and the peak wavelength of the light emitted from the second light source unit. Unit,
    A second optical path combining the optical path of the light combined by the first optical path combining means and the optical path of the light emitted from the third light source unit, and supplying the combined light to the endoscope; Optical path synthesis means;
    Further comprising
    The endoscope light source device according to claim 2 or 3.
  5. 　前記第１の光源ユニットは、
    　　前記第１の固体発光素子から射出された前記第１の波長帯域の光によって励起され、前記第１の蛍光のピーク波長とは異なるピーク波長をもつ第３の蛍光を発する第３の蛍光体を更に有し、
    　前記蛍光体挿抜手段により前記第１の蛍光体が前記第１の固体発光素子から射出される光の光路に挿入されると、前記第１の光源ユニットから該第１の波長帯域の光、前記第１の蛍光、前記第３の蛍光が同一の光路で射出されて内視鏡に供給され、
    　前記蛍光体挿抜手段により前記第１の蛍光体が前記第１の固体発光素子から射出される光の光路から抜去されると、前記第１の光源ユニットから該第１の波長帯域及び前記第３の蛍光が同一の光路で射出されて前記内視鏡に供給される、
    請求項１から請求項４の何れか一項に記載の内視鏡用光源装置。     The first light source unit is
    A third phosphor that emits a third fluorescence having a peak wavelength different from the peak wavelength of the first fluorescence, excited by light in the first wavelength band emitted from the first solid-state light emitting element; In addition,
    When the first phosphor is inserted into the optical path of the light emitted from the first solid state light emitting device by the phosphor insertion / extraction means, the light of the first wavelength band from the first light source unit, The first fluorescence and the third fluorescence are emitted in the same optical path and supplied to the endoscope;
    When the first phosphor is removed from the optical path of the light emitted from the first solid state light emitting device by the phosphor insertion / extraction means, the first wavelength band and the third wavelength are extracted from the first light source unit. Are emitted in the same optical path and supplied to the endoscope.
    The light source device for endoscopes according to any one of claims 1 to 4.
  6. 　前記第１の光源ユニットは、
    　　前記第１の固体発光素子から射出された前記第１の波長帯域の光によって励起され、前記第１の蛍光のピーク波長及び前記第３の蛍光のピーク波長とは異なるピーク波長をもつ第４の蛍光を発する第４の蛍光体を更に備え、
    　前記蛍光体挿抜手段は、
    　　前記第１の蛍光体及び前記第４の蛍光体を、前記第１の固体発光素子から射出される光の光路に対して個別に挿抜可能に支持する、
    請求項５に記載の内視鏡用光源装置。     The first light source unit is
    A fourth wavelength which is excited by the light in the first wavelength band emitted from the first solid state light emitting device and has a peak wavelength different from the peak wavelength of the first fluorescence and the peak wavelength of the third fluorescence. A fourth phosphor that emits fluorescence;
    The phosphor insertion / extraction means includes
    The first phosphor and the fourth phosphor are supported so as to be individually insertable / removable with respect to an optical path of light emitted from the first solid state light emitting device,
    The light source device for an endoscope according to claim 5.
  7. 　所定の撮像周期と同期して回転するターレット
    を更に備え、
    　前記ターレットには、夫々異なる発光特性を持つ蛍光体が周方向に並べて配置されており、
    　前記ターレットが回転することによって前記照射光の光路に各蛍光体が順に挿入されると、該照射光が、順次、該光路上に挿入された蛍光体に応じた光となって前記内視鏡に供給される、
    請求項１から請求項６の何れか一項に記載の内視鏡用光源装置。     A turret that rotates in synchronization with a predetermined imaging cycle;
    In the turret, phosphors having different emission characteristics are arranged side by side in the circumferential direction,
    When each phosphor is sequentially inserted into the optical path of the irradiation light by rotating the turret, the irradiation light sequentially becomes light corresponding to the phosphor inserted on the optical path. Supplied to the
    The light source device for endoscopes according to any one of claims 1 to 6.
  8. 　請求項１から請求項７の何れか一項に記載の内視鏡用光源装置と、
    　内視鏡と、
    を備える、
    内視鏡システム。     The endoscope light source device according to any one of claims 1 to 7,
    An endoscope,
    Comprising
    Endoscope system.
PCT/JP2017/006123 2016-02-19 2017-02-20 Endoscope light source device and endoscope system WO2017142096A1 (en)

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