JPWO2016059906A1 - Endoscope device and light source device for endoscope - Google Patents

Abstract

The endoscope apparatus receives light from a subject illuminated by illumination light, generates an imaging signal of the subject, and light in first and second wavelength bands for irradiating the subject. And an image signal in which imaging signals generated from the respective return lights from the subject irradiated with light in the first and second wavelength bands are assigned to different colors, respectively. The amount of light of the third wavelength band including the wavelength at which the absorbance of blood in the subject reaches the maximum value or the irradiation time among the light of the first wavelength band, Compared to the light amount of light in the wavelength band other than the third wavelength band, the first light amount adjustment unit to be increased, and the light absorbance of the subject in the second wavelength band of light reaches the maximum value. The amount of light in the fourth wavelength band including the wavelength, or the irradiation time A second light quantity adjusting unit that reduces in comparison with the amount of the fourth other than the wavelength band of light of the light of the second wavelength band, a.

Description

  The present invention relates to an endoscope apparatus that images a living tissue illuminated with light of a plurality of wavelength bands.

In recent years, endoscope apparatuses have been widely used in the medical field and the like. When observing a subject such as a living tissue with an endoscope apparatus, there is a conventional example that improves the clarification and visibility of an observation target.
For example, Japanese Unexamined Patent Application Publication No. 2013-81709 as a first conventional example generates and images a subject according to a light quantity ratio between first illumination light and second illumination light that illuminates the subject. An endoscope apparatus including a concavo-convex-enhanced image generating unit that generates a concavo-convex-enhanced image in which only the concavo-convex on a biological tissue is enhanced by adjusting the color characteristic value of the subject image is disclosed.
Japanese Patent Application Laid-Open No. 2013-99510 as a second conventional example includes an illumination unit that irradiates a subject with illumination light, an image signal acquisition unit that obtains an image signal from reflected light from the subject, Disclosed is an endoscope apparatus comprising: a concavo-convex image generating unit that generates a concavo-convex image in which the visibility of the concavo-convex on a living tissue is relatively improved by suppressing display of blood vessels in a subject based on the image signal. ing.

However, in the first conventional example and the second conventional example, when an image in which the traveling state of a specific blood vessel on the surface layer of a subject is emphasized as an observation target is acquired, It is not disclosed to clearly observe the observation target by suppressing the influence of blood vessels such as the middle layer region.
The present invention has been made in view of the above-described points. An endoscope apparatus that emphasizes an observation target, suppresses the non-observation target, and makes it possible to clearly observe the observation target in distinction from the non-observation target. The purpose is to provide.

  An endoscope apparatus according to an aspect of the present invention receives light from a subject illuminated by illumination light, generates an imaging signal for the subject, and a first for irradiating the subject. A light generation unit that generates, as the illumination light, light in a second wavelength band different from the first wavelength band, and light in the first wavelength band in the imaging device. An imaging signal generated by receiving the irradiated return light from the subject, and an imaging signal generated by receiving the return light from the subject irradiated with the light of the second wavelength band; , And an image signal generator that generates image signals assigned to different colors, and a third wavelength band that includes a wavelength at which the absorbance of blood in the subject has a maximum value among the light in the first wavelength band. The amount of light or the irradiation time is determined by the light in the first wavelength band. Among them, the first light amount adjustment unit to be increased as compared with the light amount of light other than the third wavelength band, and the wavelength at which the absorbance of blood in the subject becomes the maximum value among the light of the second wavelength band. A second light amount adjustment unit that reduces the amount of light in the fourth wavelength band, or the irradiation time, as compared with the amount of light in the second wavelength band other than the fourth wavelength band. .

FIG. 1 is a diagram showing an overall configuration of an endoscope apparatus according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating an emission spectrum of illumination light generated by the light source device. FIG. 3 is a diagram showing an emission spectrum of illumination light generated by the light source device in an enhancement mode for emphasizing superficial blood vessels. FIG. 4 is a flowchart showing the operation content of the first embodiment. FIG. 5 is a diagram illustrating an overall configuration of an endoscope apparatus according to a modified example of the first embodiment. FIG. 6 is a diagram illustrating an emission spectrum of illumination light generated by the light source device according to a modification. FIG. 7 is a diagram showing an emission spectrum of illumination light generated by the light source device in the enhancement mode. FIG. 8 is a diagram showing a configuration of a light generation device provided at the distal end portion of the endoscope according to the second embodiment of the present invention. FIG. 9 is a view showing an emission spectrum of illumination light and the like in the second embodiment. FIG. 10 is a diagram showing an emission spectrum of illumination light in the enhancement mode. FIG. 11 is an explanatory diagram when the exposure time of some illumination light is increased in the enhancement mode.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
As shown in FIG. 1, an endoscope apparatus 1 according to a first embodiment of the present invention includes an endoscope 3 for observing the inside of a patient 2 as a subject, illumination light, and generated illumination light. A light source device 4 that forms a light generation unit that supplies light to an endoscope, and a video processor that forms an image generation unit that performs signal processing on an imaging signal captured by an imaging device of the endoscope 3 and generates an image signal 5 and a monitor 6 that forms a display device that displays an image picked up by the image pickup device as an endoscopic image by inputting an image signal.
The endoscope 3 has an elongated insertion portion 11, an operation portion 12 provided at a proximal end (rear end) of the insertion portion 11, and a cable portion 13 having a proximal end extended from the operation portion 12. The connector 13 a at the end of the cable portion 13 is detachably connected to the light source device 4. One end of a cable 14 is connected to the connector 13a, and the other end of the cable 14 is detachably connected to the video processor 5.

A light guide 15 that transmits illumination light is inserted into the endoscope 3, and the end of the light guide 15 reaches the connector 13a. Illumination light generated by the light source device 4 is incident on the end of the light guide 15 serving as a light incident end, the incident illumination light is transmitted by the light guide 15, and the transmitted illumination light is transmitted to the distal end of the insertion portion 11. The light is further emitted from the distal end surface of the light guide 15 disposed in the illumination window provided in the portion 11a through the illumination lens 16 to the front side, and illuminates the inside of the patient 2.
An observation window is provided adjacent to the illumination window at the distal end portion 11a of the insertion portion 11, and an objective lens 17 for connecting an optical image is disposed in the observation window. A charge coupled device (abbreviated as CCD) 18 is arranged. A color filter 19 that forms a color separation unit that optically separates colors is disposed on the imaging surface of the CCD 18, and the light imaged on the imaging surface of the CCD 18 is red (R), green (G), blue in units of pixels. Color separation is performed in (B).
That is, in the color filter 19, R filters 19R, G filters 19G, and B filters 19B that transmit the R, G, and B wavelength bands, respectively, are arranged in a mosaic pattern on the imaging surface in units of pixels. The transmission characteristics of the R filter 19R, G filter 19G, and B filter 19B are shown in FIGS.

The CCD 18 passes through a signal line inserted through the endoscope 3 and a signal line in the cable 14, and a CCD driver 32 and a correlated double sampling circuit (CDS circuit) constituting the image signal generation circuit 30 in the video processor 5. (Abbreviation) 33. The CCD 18 outputs an imaging signal obtained by photoelectrically converting an optical image formed on the imaging surface when the CCD drive signal generated by the CCD driver 32 is applied, and this imaging signal is input to the CDS circuit 33 to be a signal. The component is converted into an extracted image signal.
The operation unit 12 of the endoscope 3 includes a normal light observation mode (abbreviated as normal mode) in which observation is performed with normal light, and a superficial blood vessel emphasis mode (abbreviated simply as emphasis mode) for generating an image in which the superficial blood vessels are emphasized. There is provided a changeover switch 20a for performing an instruction operation to switch between. The surgeon operates the changeover switch 20a to switch between the normal mode and the enhancement mode so that the endoscopic image in each mode can be observed.

In this embodiment, when the mode is switched by changing the changeover switch 20a, the light source device 4 and the video processor 5 are configured to perform operations corresponding to the respective modes as described below. Further, the endoscope 3 includes an ID generation circuit 20b that generates identification information (abbreviated as ID) unique to each endoscope 3. The ID generated by the ID generation circuit 20b is input to the video processor 5, for example, and used for image processing.
As shown in FIG. 1, the light source device 4 includes an R-light emitting diode (abbreviated as LED) 21R that generates red light (also referred to as R light) in a red wavelength band, and green light (also referred to as G light) in a green wavelength band. G1-LED 21G that generates blue light near the center in the blue wavelength band (also referred to as B1 light), and blue light on the short wavelength side (around 410 nm) in the blue wavelength band. B2-LED 21B2 that generates (also referred to as B2 light). A lens 22 is disposed in front of each of the R-LED 21R, G-LED 21G, B1-LED 21B1, and B2-LED 21B2, and each lens 22 converts the light from each LED into a parallel light flux.

Further, three dichroic mirrors 23a, 23b, and 23c are disposed on the optical path through which the light from each LED travels, and a condensing lens 24 is disposed on the optical path that faces the dichroic mirror 23c. The lens 24 condenses the light transmitted through the dichroic mirror 23 c or reflected by the dichroic mirror 23 c and makes it incident on the light incident end of the light guide 15.
The light source device 4 corresponds to mode switching by the LED drive circuit 25 that drives the R-LED 21R, G-LED 21G, B1-LED 21B1, and B2-LED 21B2, and the LED drive circuit 25 and the changeover switch 20a. And a control circuit 26 that controls the operation of the light source device 4.
FIG. 2 shows spectral intensities of R light, G light, B1 light, and B2 light generated by the R-LED 21R, G-LED 21G, B1-LED 21B1, and B2-LED 21B2, respectively.

In addition, when observing the vicinity of the living body surface, R light is emitted in a wavelength region suitable for observing a blood vessel near the deep layer (referred to as a deep blood vessel), and G light is a blood vessel near the middle layer (referred to as a middle blood vessel). Is emitted in a wavelength region suitable for observing, B1 light is emitted in a wavelength region where blood in the blood vessels near the surface layer (referred to as surface blood vessels) is low in absorption by blood, and B2 light has a peak in absorption by blood in the surface blood vessels. The light is emitted in a high wavelength region (wavelength region where the absorbance is maximum). Note that the wavelength near 540 nm in the G light is a wavelength at which the absorbance of the blood in the middle blood vessel becomes the maximum value.
The R-LED 21R generates R light that becomes broadband light within the transmission wavelength band of the R filter 19R, and the G-LED 21G generates G light that becomes broadband light within the transmission wavelength band of the G filter 19G. .
The B1-LED 21B1 generates B1 light that becomes light in a narrow band within the transmission wavelength band of the B filter 19B. The B2-LED 21B2 generates B2 light as narrowband light on a shorter wavelength side than the B1 light within the transmission wavelength band of the B filter 19B.

The dichroic mirror 23a is configured to selectively transmit R light and selectively reflect G light, and the dichroic mirror 23b selectively reflects B1 light and transmits light in other wavelength regions. The dichroic mirror 23c is set to a characteristic that selectively reflects B2 light and selectively transmits light in other wavelength regions.
Therefore, the R light is selectively transmitted through the dichroic mirror 23 a, further transmitted through the dichroic mirrors 23 b and 23 c, collected by the condenser lens 24, and incident on the light incident end of the light guide 15. The G light is selectively reflected by the dichroic mirror 23a, further passes through the dichroic mirrors 23b and 23c, is collected by the condenser lens 24, and enters the light incident end of the light guide 15. The B1 light is selectively reflected by the dichroic mirror 23b, further passes through the dichroic mirror 23c, is condensed by the condenser lens 24, and enters the light incident end of the light guide 15. The B2 light is selectively reflected by the dichroic mirror 23c, collected by the condenser lens 24, and incident on the light incident end of the light guide 15.

The light source device 4 includes a dimming filter 27 that can be inserted into and removed from the optical path between the G-LED 21G and the dichroic mirror 23a, and a drive that moves the dimming filter 27 to a position on the optical path. A filter insertion / removal device 28 that performs driving to move to a position retracted from the optical path is provided.
The dimming filter 27 exhibits a transmission characteristic as indicated by a dotted line in FIG. In other words, the transmission characteristic is set to reduce (or reduce) light around 540 nm where the absorbance by the blood of the middle layer blood vessel in the transmission band of the G filter 19G becomes the maximum value. By interpolating this dimming filter 27, the G light is transmitted through the transmission characteristics of the dimming filter 27 and becomes G illumination light. The influence of contrast is reduced.
When the normal mode is selected by the changeover switch 20a, the control circuit 26 causes the four R-LEDs 21R, G-LEDs 21G, B1-LEDs 21B1, and B2-LEDs 21B2 to emit light at the same time. Control is performed so that light is emitted with characteristics similar to those shown in FIG.

On the other hand, when the emphasis mode is selected by the changeover switch 20a, the control circuit 26 causes the four R-LEDs 21R, G-LEDs 21G, B1-LEDs 21B1, and B2-LEDs 21B2 to emit light simultaneously. Is controlled so as to emit light with characteristics substantially similar to those shown in FIG. 3, and the dimming filter 27 is controlled to be inserted in the optical path of the G light. As shown in FIG. 3, the control circuit 26 controls the light emission amount of the B1-LED 21B1 by the LED drive circuit 25, for example, by reducing the drive current so that the light emission intensity of the B1 light is sufficiently reduced.
That is, when the enhancement mode is selected, the LED drive circuit 25 emits the light amount of the B2 light including the wavelength with the maximum absorbance in the B transmission wavelength band of the B filter 19B in the wavelength band other than the B2 light. A (first) light amount adjustment unit (or light amount adjustment circuit) 25a that is increased as compared with the light amount of the B1 light is formed. In the example shown in FIG. 3, the light amount of the B2 light is increased by reducing the light amount of the B1 light, but the B1 light is increased by increasing the light amount of the B2 light. The B2 light may be increased as compared to the amount of light, or the amount of B2 light may be increased and the amount of B1 light may be reduced (decreased). Further, a filter for reducing the intensity of B1 light may be disposed on the optical path. For example, a filter that reduces the intensity of the B1 light may be disposed on the optical path between the B1-LED 21B1 and the dichroic mirror 23b.

For example, when the enhancement mode is selected, the LED drive circuit 25 (the light amount adjustment unit 25a) increases the drive current for causing the B2-LED 21B2 to emit light so as to increase the light amount of the B2 light, and reduces the light amount of the B1 light. It may be adjusted so as to reduce the drive current for causing the B1-LED 21B1 to emit light, or the B1 light intensity may be reduced by a filter. Further, when the light amount is adjusted so as to reduce the light amount of B1 light, the case where the light amount of B1 light is reduced to 0 (the drive current is set to 0) may be included. Moreover, the filter 27 for dimming and the filter insertion / removal device 28 are configured to reduce the light amount in the wavelength band of 540 nm to 580 nm at which the absorbance in the G light of the G-LED 21G is maximum in the G transmission wavelength band of the G filter 19G. A (second) light amount adjusting unit (or a light amount adjusting circuit) 29 is formed which is reduced (decreased) by the transmission characteristics of the light reducing filter 27 as compared with the light amount in a wavelength band other than the wavelength band of 540 nm to 580 nm.
When the mode change is performed by the changeover switch 20a, the control circuit 26 sends the mode change information to the control circuit 31 of the video processor 5, and the control circuit 31 also performs control corresponding to the mode change in the video processor 5. Do.

In addition, the video processor 5 receives an imaging signal obtained by receiving the return light from the subject irradiated with the R light, G light, B1 light, and B2 light by the CCD 18 including the R, G, B filters 19R, 19G, and 19B. The image signal generation circuit 30 forms an image signal generation unit that generates image signals assigned to three different colors.
The image signal generation circuit 30 includes a control circuit 31 that controls the operation of the bidet processor 5, a CCD driver 32 that drives the CCD 18, a CDS circuit 33 that performs CDS processing on an imaging signal output from the CCD 18, and a CDS circuit 33. An A / D conversion circuit 34 that performs A / D conversion of the output signal and a brightness detection circuit 35 that detects the brightness of the imaging signal (for example, the average luminance of the imaging signal) from the output signal of the CDS circuit 33.
The brightness signal detected by the brightness detection circuit 35 is input to the dimming circuit 36, and a dimming signal for dimming is generated based on a difference from the reference brightness (target dimming value). The dimming signal of the dimming circuit 36 is input to the LED driving circuit 25 of the light source device 4, and the LED driving circuit 25 emits four LEDs so that the brightness of the generated image becomes the reference brightness. Adjust the light intensity.

When adjusting the amount of light, in the normal mode and the emphasis mode, in the state of the light emission intensity of the four LEDs in each mode (light emission state shown in FIG. 2 or FIG. 3), the relative light emission intensity of the four LEDs. Adjust to maintain the ratio of.
The digital image signal output from the A / D conversion circuit 34 is input to the color separation circuit 37. The color separation circuit 37 is arranged in an array of R, G, B filters 19R, 19G, 19B of the color filter 19 of the CCD 18. In accordance with the color separation, R, G, and B signals are generated. In this case, the control circuit 31 acquires the ID of the endoscope 3 and controls color separation by the color separation circuit 37 according to the acquisition result.
The R, G, B signals output from the color separation circuit 37 are input to variable gain amplifiers 38a, 38b, 38c forming the white balance circuit 38, and the gain is adjusted. In the normal mode, the variable gain amplifiers 38a, 38b, and 38c are controlled by the control circuit 31 so that the signal levels of the R, G, and B signals as image signals generated when the white reference subject is illuminated are equalized. Gain is set.

The output signals of the variable gain amplifiers 38a, 38b, and 38c are stored in the R memory 39a, the G memory 39b, and the B memory 39c for one frame period, and then recalled at the same time for color discrimination and color correction (or color conversion processing). The color is input to the color discrimination / color correction circuit 40 that performs. As will be described later (see FIG. 11), in the enhancement mode, the light amount adjusting unit is changed by changing the irradiation time and the period of the CCD drive signal by setting the two frame periods in the normal mode as one frame period. You may make it give the function similar to 25a.
The color discrimination / color correction circuit 40 operates in the enhancement mode, and is controlled by the control circuit 31 so as to output the input signal through in the normal mode.
In the emphasis mode, the color discrimination / color correction circuit 40 absorbs blue light for the surface blood vessels, so that the synthesized image obtained by synthesizing the R, G, and B channel images displayed on the monitor 6 becomes yellow. End up. Since yellow has low visibility due to human visual characteristics, the color discrimination / color correction circuit 40 detects yellow, and when yellow is detected, corrects or performs color conversion processing to another color. Parameters such as other colors when correcting to other colors and correction levels when correcting colors to other colors are stored in, for example, a memory 31 a provided in the control circuit 31.

  The endoscope apparatus 1 of the present embodiment receives light from a subject illuminated by illumination light, and irradiates the subject with a CCD 18 that forms an imaging element that generates an imaging signal of the subject. A light source device 4 that forms a light generating unit that generates, as the illumination light, light in the first wavelength band and light in a second wavelength band different from the first wavelength band; An imaging signal generated by receiving return light from the subject irradiated with light in the first wavelength band and return light from the subject irradiated with light in the second wavelength band An image signal generation circuit 30 that forms an image signal generation unit that generates an image signal in which imaging signals generated by receiving light are assigned to different colors, and in the subject in the light of the first wavelength band Including the wavelength at which the absorbance of blood reaches its maximum value Forming a first light amount adjustment unit that increases the light amount or the irradiation time of light in the third wavelength band as compared with the light amount of light in the first wavelength band other than the third wavelength band. The amount of light in the fourth wavelength band including the wavelength at which the absorbance of the blood in the subject reaches a maximum value, or the irradiation time of the light in the second wavelength band, or the irradiation time of the second wavelength band. And a light amount adjustment unit 29 that forms a second light amount adjustment unit that reduces the amount of light in a band other than the light in the fourth wavelength band.

The light in the two wavelength bands, that is, the light in the G wavelength band that is transmitted through the G filter 19G and the light in the R wavelength band that is transmitted through the R filter 19R, is set to the enhancement mode as light in the second wavelength band. In this case, the amount of light of two wavelength bands may be adjusted simultaneously.
Next, the operation of this embodiment will be described with reference to FIG. As shown in FIG. 1, the endoscope 3 is connected to the light source device 4 and the video processor 5, and the respective power supplies are turned on to set the operation state. As shown in step S1, in the initial state, the endoscope apparatus 1 is activated in the normal mode. That is, as shown in step S2, the four LEDs of the light source device 4 generate illumination light of R light, G light, B1 light, and B2 light. The light emission intensity in that case is as shown in FIG. 2, for example.
The image signal generation circuit 30 of the video processor 5 operates in the normal mode. In this case, as shown in step S3, the white balance circuit 38 displays a white image on the monitor 6 when the white subject is illuminated with the illumination light of the R light, G light, B1 light, and B2 light. Further, the gains of the amplifiers 38a, 38b, and 38c are adjusted by the control circuit 31. In other words, the white balance circuit 38 is set to the gain for the normal mode corresponding to the operation state for the normal mode.

When the endoscope 3 is inserted into the patient 2 as shown in step S4, the living tissue inside the body is illuminated as shown in step S5, and an image obtained by imaging the illuminated living tissue is usually displayed on the monitor 6. Displayed as a mode image. In this case, the dimming circuit 36 operates so that an image with appropriate brightness is displayed.
When the surgeon desires to grasp the running state of the superficial blood vessels near the superficial layer in the body tissue in the body, the operator operates the changeover switch 20a to switch to the emphasis mode. As shown in step S6, the control circuit 26 monitors switching of the changeover switch 20a (switching to the emphasis mode). If switching to the emphasis mode is not performed, the process returns to step S5. If switching to the emphasis mode is performed, the process proceeds to the next step S7.
In step S7, the LED drive circuit 25 (the light amount adjusting unit 25a) reduces the light amount emitted by the B1-LED 21B1 as shown in FIG. By reducing the amount of light emitted by the B1-LED 21B1, an imaging signal that significantly reflects a change in contrast due to light absorption near 410 nm by blood in the surface blood vessels can be acquired from the transmitted light of the B filter 19B. Become.

That is, since the light reception by the light in the wavelength band other than the vicinity of 410 nm by the blood of the surface blood vessel in the transmission wavelength band of the B filter 19B is reduced, the imaging signal that remarkably reflects the change in contrast due to the light absorption by the blood of the surface blood vessel Will be able to get. As described above, the light amount adjusting unit 25a may reduce the light amount emitted by the B1-LED 21B1 and increase the light amount of the B2 light by the B2-LED 21B2.
In step S8, the control circuit 26 of the light source device 4 controls the filter insertion / removal device 28, and inserts the dimming filter 27 on the optical path of the G-LED 21G. By inserting the dimming filter 27 in the optical path of the G-LED 21G, it is possible to reduce the influence of contrast change due to light absorption at 540 to 580 nm by the blood of the middle blood vessel when illuminated with G light as shown in FIG. .
Further, as shown in step S9, the control circuit 31 switches the gains of the amplifiers 38a, 38b, and 38c of the white balance circuit 38 to gains for the enhancement mode different from those in the normal mode. For example, the gain of the amplifier 38c is made smaller than those of the other two amplifiers 38a and 38b, thereby reducing the influence of the contrast change in absorption by the blood in the deep blood vessels.

Further, as shown in step S10, the control circuit 31 turns on the operation of the color discrimination / color correction circuit 40, and in the enhancement mode, corrects the yellow tone discriminated from the three color signals to red or blue tone. . Visibility can be improved by color correction.
Then, as shown in step S11, an image in the enhancement mode is displayed on the monitor 6.
In the next step S12, the control circuit 26 monitors the switch from the emphasis mode to the normal mode by the changeover switch 20a. If the switch to the normal mode is not performed, the control circuit 26 returns to the process of step S11 and returns to the normal mode. If switching has been performed, the process proceeds to the next step S13.
In step S13, the control circuit 26 controls the filter insertion / removal device so that the dimming filter 27 is retracted from the optical path. In step S14, the LED drive circuit 25 stops the operation of the light amount adjusting unit 25a performed in step S7, and stops the light amount reduction of the B1 light. In step S15, the control circuit 31 switches the gains of the amplifiers 38a, 38b, and 38c of the white balance circuit 38 to gains for the normal mode. Further, in step S16, the control circuit 31 stops the operation of the color discrimination / color correction circuit 40 (OFF), and then returns to the process of step S5.

According to this embodiment that operates in this manner, the observation target (characteristic) is emphasized, the non-observation target (effect on the characteristics of the observation target) is suppressed, and the observation target is clearly distinguished from the non-observation target. Makes it possible to observe. More specifically, emphasis is made so that the running state of the surface blood vessels to be observed can be easily identified, the influence of contrast changes caused by the middle layer blood vessels to be non-observed is suppressed, and the running state of the surface blood vessels is clearly observed. Make it possible.
In the emphasis mode, the color tone is likely to be lowered due to the absorption of blue light by the blood in the surface blood vessels, but color correction or color conversion is performed, so the running state of the surface blood vessels can be changed. It can be observed in a state that is easy to visually recognize.
In the above-described first embodiment, in order to reduce the influence of contrast change due to light absorption near 600 nm by blood of deep blood vessels, in the enhancement mode, as shown by a two-dot chain line in FIG. A filter 27b for dimming that transmits a wavelength band longer than the vicinity of 600 nm may be disposed on the optical path between the R-LED 21R and the dichroic mirror 23a. Note that the transmission characteristics of the light attenuation filter 27b are indicated by a two-dot chain line in FIG. In this way, the influence of contrast change due to selective light absorption by blood in deep blood vessels can be further reduced.

FIG. 5 shows an endoscope apparatus 1B according to a modification of the first embodiment. In this modification, in the first embodiment shown in FIG. 1, G1-LED 21G1 and G2-LED 21G2 are provided instead of G-LED 21G, and LED drive circuit 25 drives G1-LED 21G1 and G2-LED 21G2. It has a configuration. The light emission characteristics in the normal mode of the G1-LED 21G1 and the G2-LED 21G2 are shown in FIG.
The R light in FIG. 5 is selectively transmitted through the dichroic mirror 23d and further selectively transmitted sequentially through the dichroic mirrors 23e, 23b, and 23c. The G1 light is selectively reflected by the dichroic mirror 23d and is selectively transmitted sequentially through the dichroic mirrors 23e, 23b, and 23c. The G2 light is selectively reflected by the dichroic mirror 23e and selectively transmitted through the dichroic mirrors 23b and 23c sequentially.
Further, the endoscope apparatus 1B of FIG. 5 is not provided with the light reduction filter 27 and the filter insertion / removal device 28. Then, the light amount adjustment unit 25a in the LED drive circuit 25 performs light amount adjustment that adjusts so as to reduce the light amount of the G1-LED 21G1 together with the light amount of the B1-LED 21B1 (decrease both driving currents) in the enhancement mode. Do.

In the case of this modification, in the normal mode, five LEDs are caused to emit light as shown in the characteristics shown in FIG. The operation is almost the same as in the first embodiment.
On the other hand, in the enhancement mode, the light amount adjustment unit 25a in the LED drive circuit 25 performs light amount adjustment for reducing the light amount of the G1-LED 21G1 together with the light amount of the B1-LED 21B1, as shown in the characteristic shown in FIG. Do. The effect of this modification is substantially the same as that of the first embodiment.
In the first embodiment, in the enhancement mode, the influence of the change in the control due to the light absorption at 540 to 580 nm is reduced by using the filter 27 for dimming. However, in this modification, the amount of light emitted by the G1-LED 21G1 By reducing the above, substantially the same effect can be obtained.
In the same manner as described in the first embodiment, in the enhancement mode, the light amount adjusting unit 25a reduces the light amount of the G1-LED 21G1 together with the light amount of the B1-LED 21B1, and the B2-LED 21B2. The light amount may be controlled to increase, or the light amount adjustment unit 25a may be controlled to increase the light amount of the B2-LED 21B2. As will be described later, instead of reducing the light amount of the B1-LED 21B1 and the light amount of the G1-LED 21G1, instead of reducing the irradiation time of the B1-LED 21B1 and the G1-LED 21G1, or increasing the light amount of the B2-LED 21B2. Alternatively, the light amount may be adjusted by increasing the irradiation time of the B2-LED 21B2.
In the first embodiment or its modification, two LEDs, one that generates light on the long wavelength side of R light and one that generates light on the short wavelength side of R light, are used instead of the R-LED 19R. It may be used. In this case, when the mode is switched to the enhancement mode, the light amount of the latter short wavelength side (near 600 nm) may be reduced or suppressed.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 8 shows a schematic configuration of a light generation device 61 using a phosphor 62 on the distal end side of the insertion portion 11 of the endoscope 3 in the second embodiment. In the present embodiment, illumination light is generated using the phosphor 62.
In the present embodiment, the light source device includes, for example, only the B2-LED 21B2 or the B1-LED 21B1 and the B2-LED 21B2 in the four LEDs in FIG. First, the former case will be described.
In the case of only the B2-LED 21B2, the B2 light is transmitted by the light guide 15 and becomes excitation light incident on the phosphor 62 from the front end surface of the light guide 15 as shown in FIG. 8, and the phosphor 62 is excited. Fluorescent illumination light is emitted.
The fluorescent illumination light excited by the phosphor 62 passes through the light reducing filter 63 and is then emitted to the outside through the illumination lens 16. The excitation light that has passed through the phosphor 62 is also emitted to the outside as illumination light through the illumination lens 16. The dimming filter 63 is attached to the filter frame 64, and the end of the arm of the filter frame 64 is attached to the rotation shaft of the motor 65. The rotation of the motor 65 is controlled by the control circuit 26.

In the normal mode, the control circuit 26 controls the rotation of the motor 65 so that the dimming filter 63 is out of the optical path between the phosphor 62 and the illumination lens 16 as indicated by the dotted line in FIG. Controls the rotation of the motor 65 so that the dimming filter 63 enters the optical path between the phosphor 62 and the illumination lens 16 as indicated by the solid line.
In the present embodiment, when the B2-LED 21B2 is regarded as the first light source, the B2-LED 21B2 is disposed on the optical path using the B2 light generated by the first light source as excitation light, and is excited by the B2 light. , A phosphor 62 that generates fluorescence including light having a wavelength longer than that of the B2 light and light in the green wavelength band, and a detachable arrangement on the optical path of the fluorescence generated by the phosphor 62, A light reduction filter 63 that forms a reduction unit (or reduction device) that reduces light in the wavelength band.
FIG. 9 shows the spectral intensity of the illumination light emitted from the illumination lens 16 in the normal mode. In the present embodiment, together with B2 light serving as excitation light, the phosphor 62 causes light having an intensity distribution close to that of the B1 light in the first embodiment (fluorescence indicated by B1 ′ in FIG. 9) and a wavelength from green to red. Broadband light (fluorescent illumination light 71) extending over a band is emitted from the illumination lens 16 as illumination light. As will be described later, in the latter case, the B1 ′ portion in FIG. 9 is changed to B1 light.
Further, as shown in FIG. 10, the dimming filter 63 has a characteristic of transmitting B2 light serving as excitation light in the vicinity of 410 nm, attenuates or reduces B1 ′ light having a longer wavelength than B2 light, and further 480 nm. From 540 nm to the green short wavelength band side, and has a characteristic of attenuating light in the green long wavelength band which is longer wavelength side than 540 nm. In other words, the dimming filter 63 reduces the blue long-wavelength light that is longer than the B2 light that is excitation light near 410 nm and the long-wavelength light in green in the enhancement mode. Forming part. In the present embodiment, the dimming filter 63, the filter frame 64, and the motor 65, which are components for inserting the dimming filter 63 into the optical path between the phosphor 62 and the illumination lens 16, constitute the light adjusting unit. To do. Other configurations are the same as those in the first embodiment.

In the normal mode, the present embodiment operates in substantially the same manner as in the first embodiment by the illumination light shown in FIG.
When switched to the emphasis mode, the control circuit 26 sends a drive signal to the motor 65, rotates the motor 65, and changes the filter 63 for dimming with the phosphor 62 as shown by the solid line from the state shown by the dotted line in FIG. It is set in a state of being inserted in the optical path between the illumination lens 16 and the illumination lens 16.
In a state where the dimming filter 63 is inserted in the optical path, the intensity distribution with respect to the wavelength of the illumination light emitted from the illumination lens 16 has characteristics similar to those of the first embodiment.
For this reason, when the emphasis mode is set, the present embodiment has the same effect as the first embodiment.
In the latter case described above, that is, when the light source device has B1-LED 21B1 and B2-LED 21B2, phosphor 62 generates phosphor illumination light 71 in FIG. 9 by B1-LED 21B1 and B2-LED 21B2. B1 ′ in FIGS. 9 and 10 is changed to B1 light by the B1-LED 21B1. In the former case, the phosphor 62 generates the light B2 ′ together with the phosphor illumination light 71, whereas in the latter case, only the fluorescence illumination light 71 is generated and corresponds to the light B2 ′. B2 light is generated by the B2-LED 21B2. In the former case and the latter case, the same effect is obtained.
In the second embodiment, the light generation device 61 using the phosphor 62 is disposed at the distal end portion 11a of the insertion portion 11 of the endoscope 3. However, the illumination light generated by being disposed in the light source device 4 is generated. May be transmitted by the light guide 15.

Further, for example, white light may be generated by exciting the phosphor with an LED or a semiconductor laser that generates B2 light. And, in the enhancement mode, as in the first or second embodiment described above, the wavelength band in which the absorbance of the blood in the surface blood vessel becomes the maximum in the transmission wavelength band of the B filter 19B with respect to white light. In the transmission wavelength band of the G filter 19G, the light quantity in the wavelength band where the absorbance of the blood in the middle layer blood vessel becomes the maximum value is adjusted. You may make it adjust 2nd light quantity so that it may suppress compared with another wavelength band. Further, in the transmission wavelength band of the G filter 19G, there is further provided a light emitting element that emits light other than the wavelength band in which the absorbance of the blood in the middle layer blood vessel is maximum, and other than the wavelength band in which the absorbance of the blood in the middle layer blood vessel is maximum. The amount of light is adjusted so that the intensity of the wavelength band in which the absorbance of the blood in the middle-layer blood vessel reaches the maximum value in the transmission wavelength band of the G filter 19G is relatively lower than the intensity of the other wavelength bands. You may make it do.
In addition to performing the first or second light amount adjustment as described above, the first or second light amount adjustment is performed by adjusting the irradiation time (irradiating illumination light to a living tissue as a subject). You may make it acquire the substantially same effect as performing.
For example, in the first embodiment, when the enhancement mode is set, the light amount of the B1-LED 21B1 is reduced, but instead, the irradiation time by the B2-LED 21B2 may be increased. In other words, the irradiation time by the B2-LED 21B2 when the CCD 18 acquires an image for one frame may be made longer than the irradiation time by the B1-LED 19B1. Alternatively, when the enhancement mode is set, the light amount of the B1-LED 21B1 is reduced, but instead, the irradiation time by the B1-LED 21B1 may be shortened.

In the first embodiment, the four LEDs always emit light in both the normal mode and the emphasis mode. In the emphasis mode, the CCD drive signal (readout) is described as described below. ) In synchronization with the cycle, the emission time of the B2 light may be increased (extended) than the emission time of the B1 light. Note that the light emission time within the period of the CCD drive signal is the irradiation time (when an image for one frame is acquired).
FIG. 11 shows an explanatory diagram in this case. As shown in FIG. 11, when the period of the CCD drive signal is T, the B1-LED 19B1 emits light during a period ½ of the period T, whereas the B2-LED 19B2 always emits light continuously (irradiation time). LED drive circuit 25 (light quantity adjustment unit 25a) is driven so that T becomes T).
That is, the emission time (irradiation time) of B1 light for obtaining an image signal for one frame with B1 light is T / 2, whereas emission of B2 light for obtaining an image signal for one frame with B2 light. For example, the time may be adjusted so that the time T is doubled. In the example shown in FIG. 11, the R-LED 19R and the G-LED 19G always emit light continuously like the B2-LED 19B2.

Note that, in the period T, for example, in the normal mode, all LEDs are continuously lit continuously at a period of T / 2, for example. The CCD drive signal is set to be generated at a period of T / 2.
On the other hand, when the mode is switched to the emphasis mode, the light emission time by the B1-LED 21B1 is intermittent light emission at T / 2. The imaging period for imaging one frame by the CCD 18 with the B1 light of the B1-LED 21B1 is the same as that in the normal mode, whereas an image for one frame by the CCD 18 with the B2 light of the B2-LED 21B2 is acquired. Therefore, the imaging period for performing imaging for the imaging is extended so as to be twice that in the normal mode. Note that when the mode is switched to the enhancement mode, the light emission time may be shortened so that the light emission time by the B1-LED 21B1 is intermittent light emission in a time shorter than T / 2.
Therefore, as shown in FIG. 11, by increasing the emission time of the B2 light with respect to the emission time (irradiation time) of the B1 light, substantially the same effect as in the case of the first embodiment can be obtained. As described above, when the light emission time is varied in the enhancement mode, the period of writing in the R, G, B memories 39a, 39b, 39c is also changed according to the period of the CCD drive signal.
On the other hand, when reading from the R, G, B memories 39a, 39b, 39c, they may be read at the same cycle as in the normal mode. When the light emission time is changed as shown in FIG. 11, the same color signal may be read out twice from the R, G, B memories 39a, 39b, 39c. In the modification of the first embodiment, the light emission time (irradiation time) by the G1-LED 21G1 may be shortened together with the light emission time (irradiation time) by the B1-LED 21B1.
Note that embodiments configured by partially combining the above-described embodiments (including the modified examples) also belong to the present invention.

  This application is filed on the basis of the priority claim of Japanese Patent Application No. 2014-21785 filed in Japan on 16/16/2014, and the above disclosure is included in the present specification, claims and drawings. It shall be quoted.

The present invention relates to an endoscope apparatus and an endoscope light source apparatus that capture an image of a living tissue illuminated with light of a plurality of wavelength bands.

However, in the first conventional example and the second conventional example, when an image in which the traveling state of a specific blood vessel on the surface layer of a subject is emphasized as an observation target is acquired, It is not disclosed to clearly observe the observation target by suppressing the influence of blood vessels such as the middle layer region.
The present invention has been made in view of the above-described points. An endoscope apparatus that emphasizes an observation target, suppresses the non-observation target, and makes it possible to clearly observe the observation target in distinction from the non-observation target. And it aims at providing the light source device for endoscopes .

The endoscope apparatus according to an embodiment of the present invention, generation and light of the first wavelength band, and light in a different second wavelength band from said first wavelength band as the illumination light for irradiating the subject A light generating unit that receives light from the subject illuminated by the illumination light and generates an imaging signal of the subject, and light of the first wavelength band is emitted from the imaging device An imaging signal generated by receiving the return light from the subject, and an imaging signal generated by receiving the return light from the subject irradiated with the light of the second wavelength band; And an image signal generator that generates image signals assigned to different colors, and light in a third wavelength band including a wavelength in which the absorbance of blood in the subject has a maximum value among the light in the first wavelength band The amount of light or the irradiation time of the light in the first wavelength band Compared to the Chi the third other than the wavelength band of the light, first comprises a first light quantity adjusting unit to increase, the wavelength at which the absorbance of the blood in the subject is the maximum value of the light of the second wavelength band And a second light amount adjustment unit that reduces the light amount of the fourth wavelength band or the irradiation time as compared with light of the second wavelength band other than the light of the fourth wavelength band.
An endoscope light source device according to one embodiment of the present invention is an illumination light for irradiating a subject with light in a first wavelength band and light in a second wavelength band different from the first wavelength band. A light generation unit that generates the light amount of the light in the third wavelength band including the wavelength at which the absorbance of the blood in the subject reaches the maximum value among the light in the first wavelength band, or the irradiation time, Compared with light of the first wavelength band other than the light of the third wavelength band, the first light amount adjusting unit to be increased, and of the light of the second wavelength band, blood absorbance in the subject is increased. The second light amount adjustment unit that reduces the light amount in the fourth wavelength band including the maximum wavelength or the irradiation time as compared with the light in the second wavelength band that is not in the fourth wavelength band. And having.

An endoscope apparatus according to an aspect of the present invention includes light in a first wavelength band as illumination light for illuminating a subject, light in a second wavelength band different from the first wavelength band , Receiving a light of a third wavelength band different from the first wavelength band and the second wavelength band, a light generation unit that generates the light, and light from the subject illuminated by the illumination light, and the subject An imaging signal that generates the imaging signal, an imaging signal that is generated by receiving return light from the subject irradiated with light in the first wavelength band in the imaging element, and the second wavelength band An imaging signal that is generated by receiving return light from the subject irradiated with light and a return light from the subject irradiated with light in the third wavelength band are generated and received. image signal for generating a color image signal allocated an imaging signal, to the different colors A generating unit, the first fourth wavelength band of the light amount of light having a wavelength at which the absorbance of the blood in the subject is the maximum value of the wavelength band of light, or, the irradiation time, the first wavelength band compared to the light other than the fourth wavelength band of the light increases, and a fifth containing a wavelength absorbance of the blood in the subject is the maximum value of the light of the second wavelength band The amount of light in the wavelength band or the irradiation time is reduced as compared with light in the second wavelength band other than the light in the fifth wavelength band , and out of the light in the third wavelength band The amount of light in the sixth wavelength band including the wavelength at which the absorbance of blood in the subject reaches the maximum value, or the irradiation time is set to light other than the sixth wavelength band in the light in the third wavelength band. A light amount adjustment unit that reduces the light intensity .
An endoscope light source device according to one embodiment of the present invention includes light in a first wavelength band as illumination light for illuminating a subject, and light in a second wavelength band different from the first wavelength band. A light generating unit that generates light in a third wavelength band different from the first wavelength band and the second wavelength band, and blood absorbance in the subject out of the light in the first wavelength band. Increasing the amount of light in the fourth wavelength band including the maximum wavelength, or the irradiation time, compared to light in the first wavelength band other than the fourth wavelength band , and , the second wavelength band of the fifth wavelength band of the light amount of light having a wavelength at which the absorbance of the blood in the subject is the maximum value of the light or the irradiation time, the light of the second wavelength band of reduced as compared with the fifth other than the wavelength band of light, and light of the third wavelength band Among them, the amount of light in the sixth wavelength band including the wavelength at which the absorbance of blood in the subject reaches the maximum value, or the irradiation time is set as the light in the third wavelength band other than the sixth wavelength band. A light amount adjustment unit that reduces the light intensity compared to

Claims (6)

An image sensor that receives light from a subject illuminated by illumination light and generates an imaging signal of the subject;
A light generation unit that generates, as the illumination light, light in a first wavelength band for irradiating the subject and light in a second wavelength band different from the first wavelength band;
From the imaging signal generated by receiving the return light from the subject irradiated with light in the first wavelength band in the imaging device and the subject irradiated with light in the second wavelength band An imaging signal generated by receiving the return light of the image signal, and an image signal generation unit that generates an image signal assigned to each different color,
Of the light in the first wavelength band, the amount of light in the third wavelength band including the wavelength at which the absorbance of blood in the subject reaches the maximum value, or the irradiation time is determined by the amount of light in the first wavelength band. A first light amount adjusting unit that increases the light amount of light outside the third wavelength band,
Of the light in the second wavelength band, the amount of light in the fourth wavelength band including the wavelength at which the absorbance of blood in the subject reaches the maximum value, or the irradiation time is the first light in the second wavelength band. A second light amount adjustment unit that reduces the light amount of light other than the wavelength band of 4;
An endoscope apparatus characterized by comprising: The light generation unit includes: a first light source that generates light in the third wavelength band in the first wavelength band; and light other than the third wavelength band in the first wavelength band. A second light source that generates light, a third light source that generates light in the fourth wavelength band of the second wavelength band, and the fourth wavelength band of the second wavelength band. A fourth light source that generates light other than
The first light amount adjustment unit performs control to increase the driving current of the first light source or increase the irradiation time than the second light source,
2. The endoscope apparatus according to claim 1, wherein the second light amount adjustment unit performs control to reduce a driving current of the third light source or to shorten an irradiation time as compared with the fourth light source. . In the light generation unit, the first wavelength band is a blue wavelength band, and the second wavelength band is a green wavelength band,
The light generation unit includes a first light source that generates light in the third wavelength band in the blue wavelength band;
A second light source that generates light having a longer wavelength than the third wavelength band of the blue wavelength band;
A phosphor that is provided on an optical path of light of the third wavelength band generated by the first light source, is excited by light of the third wavelength band, and emits fluorescence of at least the green wavelength band;
The fluorescent light and the long-wavelength light transmitted through the phosphor are disposed so as to be disposed on an optical path, and the light amount of the fourth wavelength band and the second light source are generated from the green wavelength band. A reduction unit that reduces the amount of long-wavelength light;
The endoscope apparatus according to claim 1, further comprising: In the light generation unit, the first wavelength band is a blue wavelength band, and the second wavelength band is a green wavelength band,
The light generating unit generates a light of the third wavelength band as excitation light in the blue wavelength band; and
Provided on the optical path of the light of the third wavelength band generated by the first light source, excited by the light of the third wavelength band, and from the third wavelength band of the blue wavelength band A phosphor that emits fluorescence including long wavelength light and green wavelength band light,
Arranged on the optical path of the fluorescence and the excitation light that has passed through the phosphor, the light amount of the fourth wavelength band of the green wavelength band and the wavelength longer than the third wavelength band A reduction unit that reduces the amount of light and light,
The endoscope apparatus according to claim 1, further comprising:   The endoscope according to claim 1, wherein the image signal generation unit performs a color conversion process on a color corresponding to a characteristic in which light in the three wavelength bands is absorbed in the image signal. apparatus. The image pickup device further includes three transmission filters each including light in the first wavelength band and light in the first wavelength band and transmitting light in the wavelength bands of the three primary colors covering the visible region. Equipped with color filters
The light generation unit simultaneously generates light of three wavelength bands so that each of the wavelength bands of the three primary colors includes light of at least one wavelength band;
The image signal generation unit generates three color signals imaged in the wavelength bands of the three primary colors from the image signals transmitted through the three transmission filters and received by the image sensor. The endoscope apparatus according to claim 1.

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