阅读说明：本技术 内窥镜系统 (Endoscope system ) 是由 岩根弘亮 于 2020-02-17 设计创作，主要内容包括：本发明提供一种内窥镜系统,当将多个光进行切换来照明时,能够根据被摄体的变化来控制各光的照明光的光量。设定光量调整部(57)进行如下步骤中的至少任一个：调整在从第1照明光切换到第2照明光的第1切换定时T1设定的第2照明光的光量的步骤；调整在从第2照明光切换到第1照明光的第2切换定时T2设定的第1照明光的光量的步骤。(The invention provides an endoscope system, which can control the light quantity of illumination light of each light according to the change of an object when a plurality of lights are switched to illuminate. The setting light amount adjustment unit (57) performs at least one of the following steps: a step of adjusting the light quantity of the 2 nd illumination light set at a 1 st switching timing T1 at which the 1 st illumination light is switched to the 2 nd illumination light; and adjusting the light quantity of the 1 st illumination light set at a 2 nd switching timing T2 at which the 2 nd illumination light is switched to the 1 st illumination light.)

1. An endoscope system comprising:

a light source section that emits 1 st illumination light and 2 nd illumination light having an emission spectrum different from the 1 st illumination light;

a 1 st processor; and

a (2) a processor for processing the data,

the 1 st processor performs the following processing:

when control is performed to automatically switch and emit the 1 st illumination light and the 2 nd illumination light, a light emission period K (N) during which the 1 st illumination light is emitted and a light emission period L (N) during which the 2 nd illumination light is emitted are set to light emission periods of at least 1 frame or more, respectively,

the 2 nd processor performs the following processing:

acquiring a 1 st image signal group and a 2 nd image signal group, the 1 st image signal group including a 1 st image signal obtained by imaging a subject illuminated by the 1 st illumination light during a light emission period K (N) of the 1 st illumination light, the 2 nd image signal group including a 2 nd image signal obtained by imaging a subject illuminated by the 2 nd illumination light during a light emission period L (N) of the 2 nd illumination light,

calculating a 1 st luminance D1 of the subject from the 1 st image signal and a 2 nd luminance D2 of the subject from the 2 nd image signal,

setting the light quantity of the 1 st illumination light or the 2 nd illumination light according to the 1 st brightness or the 2 nd brightness,

at least one of the step of adjusting the light quantity of the 2 nd illumination light set at the 1 st switching timing of switching from the 1 st illumination light to the 2 nd illumination light and the step of adjusting the light quantity of the 1 st illumination light set at the 2 nd switching timing of switching from the 2 nd illumination light to the 1 st illumination light is performed.

2. The endoscopic system of claim 1,

the 2 nd processor performs at least any one of the following steps: a step of adjusting the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) using information on the 1 st switching timing T1 of the light emission period L (N) before the light emission period L (N), or a step of adjusting the light quantity of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) before the light emission period K (N) using information on the 2 nd switching timing T2 of the light emission period K (N) before the light emission period K (N).

3. The endoscopic system of claim 2,

let N be 4, and carry out the following processing: when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (4) is adjusted, the target luminance is divided by the 2 nd luminance D2(2) of the 1 st switching timing T1 as the information on the 1 st switching timing T1 of the light emission period L (2)^*And the obtained adjustment coefficient X (2) is multiplied by the light quantity of the 2 nd illumination light.

4. The endoscopic system of claim 1,

the 2 nd processor performs at least any one of the following steps: a step of adjusting the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) using information on the 1 st switching timing T1 of a plurality of light emission periods L (N-P) before the light emission period L (N), or a step of adjusting the light quantity of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) before the light emission period K (N) using information on the 2 nd switching timing T2 of the light emission period K (N).

5. The endoscopic system of claim 4,

the 2 nd luminance D2 of the 1 st switching timing T1 includes a plurality of 2 nd luminances D2(N-P) indicating each of the 2 nd luminances of the 1 st switching timing T1 of a plurality of light emitting periods L (N-P),

the 2 nd processor performs the following processing: when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) is adjusted, a specific adjustment coefficient X, which is obtained by dividing the target luminance by a value obtained by multiplying and adding the plurality of 2 nd luminances D2(N-P) by weighting coefficients, is multiplied by the light quantity of the 2 nd illumination light as information on the 1 st switching timing T1 of the plurality of light emission periods L (N-P).

6. The endoscopic system of claim 1,

the 2 nd processor performs at least any one of the following steps: a step of adjusting the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period l (N) using information on the 2 nd switching timing T2 of the light emission period K (N-1) before the light emission period l (N), or a step of adjusting the light quantity of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) before the light emission period K (N) using information on the 1 st switching timing T1 of the light emission period K (N) before the light emission period K (N).

7. The endoscopic system of claim 6,

let N be 4, and carry out the following processing: when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (4) is adjusted, as information on the 2 nd switching timing T2 of the light emission period K (3), the light quantity of the 2 nd illumination light is multiplied by an adjustment coefficient Y (3), the adjustment coefficient Y (3) passing through the 1 st luminance D1(3) at the 2 nd switching timing in the light emission period K (3)^*Divided by the target brightness.

8. The endoscopic system of claim 1,

the 2 nd processor performs at least any one of the following steps: a step of adjusting the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) using information on the 2 nd switching timing T2 of the light emission periods K (N-Q) and the 1 st switching timing T1 of the light emission periods L (N-P) before the light emission period L (N), or a step of adjusting the light quantity of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) using information on the 1 st switching timing T1 of the light emission periods L (N-Q) and the 2 nd switching timing T2 of the light emission periods K (N-P) before the light emission period K (N).

9. The endoscopic system of claim 8,

let N be 6, and the 2 nd processor performs the following: when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 in the light emission period L (6) is adjusted, the 1 st luminance D1(5) based on the 2 nd switching timing T2 in the light emission period K (5)^*And 2 nd brightness D2(4) at 1 st switching timing T1 in the light-emitting period L (4)^*And multiplying a predetermined specific adjustment coefficient Y of the target brightness V by the light quantity of the 2 nd illumination light.

10. The endoscopic system of any of claims 1 to 9,

the 1 st luminance or the 2 nd luminance is obtained from an average of pixel values other than blood vessels or lesions in the 1 st image signal or the 2 nd image signal.

11. The endoscopic system of any of claims 1 to 10,

the 1 st luminance or the 2 nd luminance is obtained from an average of pixel values of the 1 st image signal or the 2 nd image signal except for an abnormal pixel including at least one of a dark portion and a halo, or an average of pixel values of the 1 st image signal group or the 2 nd image signal group except for the 1 st image signal or the 2 nd image signal including the abnormal pixel.

12. The endoscopic system of any of claims 1 to 11,

the 2 nd processor adjusts the light quantity of the 2 nd illumination light or the light quantity of the 1 st illumination light only when the 1 st luminance or the 2 nd luminance is within a predetermined target luminance range.

Technical Field

The present invention relates to an endoscope system that switches and displays a plurality of images.

Background

In recent years, endoscope systems including a light source device, an endoscope, and a processor device are widely used in the medical field. In an endoscope system, illumination light is irradiated from an endoscope to an observation target, and an image of the observation target is displayed on a display based on RGB image signals obtained by imaging the observation target illuminated with the illumination light by an imaging element of the endoscope.

In recent years, for diagnostic purposes, a plurality of illumination lights having different wavelength regions are illuminated on an observation target. For example, patent document 1 describes that oxygen saturation in a blood vessel included in an observation target is obtained by alternately illuminating 2 blue narrow-band lights of NB1 light having a peak wavelength of 422nm and NB2 light having a peak wavelength of 460 to 470 nm. Further, patent document 2 describes that light having a peak in a B1 region (1B region: 390nm to 440nm) and light having a peak in a B2 region (2B region: 440nm to 490nm) are illuminated on an observation target, and image information of superficial blood vessels is obtained by imaging an imaging element including B pixels having sensitivity to both the light in a B1 region and the light in a B2 region. Further, in patent document 3, desired tissue information of a living tissue is acquired in a clearer state suitable for diagnosis by using violet light having a central wavelength of 405nm, blue laser beam having a central wavelength of 445nm, and excitation light by which excitation light emission is performed by the blue laser beam.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication (Kokai) No. 2015-

Patent document 2: international publication No. 2016/080130

Patent document 3: japanese patent laid-open publication No. 2017-185258

Disclosure of Invention

Technical problem to be solved by the invention

In recent years, in the field of endoscope, diagnosis has been performed focusing on living body information other than the background mucosa, for example, blood vessels having different depths, glandular structures having different depths, and the like. In such diagnosis, it is necessary to display a plurality of pieces of information other than the background mucous membrane to the user so that the user can grasp them. As a method of representing such a plurality of pieces of information, there is considered a method of illuminating a plurality of wavelengths of light having different invasion depths into living tissue by automatically and periodically switching and displaying a plurality of images obtained by the illumination by switching. For example, in order to obtain information on a superficial layer such as a superficial blood vessel and information on a deep layer such as a deep blood vessel, short-wavelength light having an invasion depth in the superficial layer and medium-wavelength light having an invasion depth in the deep layer are switched and illuminated, and a superficial layer image obtained by illumination with the short-wavelength light and a deep layer image obtained by illumination with the medium-wavelength light are switched and displayed. Since the difference between the surface image and the deep image is displayed by performing such switching display, different pieces of living body information can be displayed separately. Therefore, different living body information of the surface layer information and the deep layer information can be grasped.

As described above, when the light of each wavelength is switched to illuminate, it is necessary to appropriately control the light amount of the light of each wavelength in accordance with the brightness of the subject. However, when the standard object and the spectral reflectance are different from each other due to a change in the object such as a difference in an observation site, a personal difference, presence or absence of a disease such as inflammation, presence or absence of pigment scattering, or the like, and the luminance, color tone, or the like of each image captured with light of a plurality of wavelengths are greatly different from each other, when the difference between the target luminance and the luminance is large when light of each wavelength is switched, the light amount of light of each wavelength does not correspond to the luminance of the object.

An object of the present invention is to provide an endoscope system capable of controlling the light quantity of illumination light of each light in accordance with a change in an object when a plurality of lights are switched to be illuminated.

Means for solving the technical problem

An endoscope system of the present invention includes: a light source section that emits 1 st illumination light and 2 nd illumination light having an emission spectrum different from that of the 1 st illumination light; a 1 st processor; and the 2 nd processor, the 1 st processor carries on the following treatment: when control is performed to automatically switch and emit the 1 st illumination light and the 2 nd illumination light, a light emission period K (N) during which the 1 st illumination light is emitted and a light emission period L (N) during which the 2 nd illumination light is emitted are set to light emission periods of at least 1 frame or more, respectively, and the 2 nd processor performs the following processing: acquiring a 1 st image signal group and a 2 nd image signal group, the 1 st image signal group including a 1 st image signal obtained by photographing a subject illuminated by the 1 st illumination light during a light emission period K (N) of the 1 st illumination light, the 2 nd image signal group includes a 2 nd image signal obtained by photographing an object illuminated by the 2 nd illumination light during a light emission period L (N) of the 2 nd illumination light, calculates a 1 st luminance D1 of the subject from the 1 st image signal, and calculates a 2 nd luminance D2 of the subject from the 2 nd image signal, the light quantity of the 1 st illumination light or the 2 nd illumination light is set according to the 1 st brightness or the 2 nd brightness, and at least one of the step of adjusting the light quantity of the 2 nd illumination light set at the 1 st switching timing for switching from the 1 st illumination light to the 2 nd illumination light and the step of adjusting the light quantity of the 1 st illumination light set at the 2 nd switching timing for switching from the 2 nd illumination light to the 1 st illumination light is performed.

Preferably, the 2 nd processor performs at least any one of the following steps: a step of adjusting the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) using the information on the 1 st switching timing T1 of the light emission period L (N-2) before the light emission period L (N), or a step of adjusting the light quantity of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) before the light emission period K (N) using the information on the 2 nd switching timing T2 of the light emission period K (N-2).

Preferably, N is 4, and the following processing is performed: when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (4) is adjusted, as information on the 1 st switching timing T1 of the light emission period L (2), the target luminance is divided by the 2 nd luminance D2(2) of the 1 st switching timing T1^*And the obtained adjustment coefficient X (2) is multiplied by the light quantity of the 2 nd illumination light.

Preferably, the 2 nd processor performs at least one of the step of adjusting the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) using the information on the 1 st switching timing T1 of the plurality of light emission periods L (N-P) preceding the light emission period L (N), and the step of adjusting the light quantity of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) preceding the light emission period K (N) using the information on the 2 nd switching timing T2 of the light emission period K (N-P).

Preferably, the 2 nd luminance D2 of the 1 st switching timing T1 includes a plurality of 2 nd luminances D2(N-P) indicating each of the 2 nd luminances of the 1 st switching timing T1 of the plurality of light emitting periods L (N-P), and the 2 nd processor performs the following processing: when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) is adjusted, as information on the 1 st switching timing T1 of the plurality of light emission periods L (N-P), a specific adjustment coefficient X, in which the target luminance is a value obtained by multiplying and adding the plurality of 2 nd luminances D2(N-P) by weighting coefficients, respectively, is multiplied by the light quantity of the 2 nd illumination light.

Preferably, the 2 nd processor performs at least any one of the following steps: a step of adjusting the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) using the information on the 2 nd switching timing T1 of the light emission period K (N-1) before the light emission period L (N), or a step of adjusting the light quantity of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) before the light emission period K (N) using the information on the 1 st switching timing T1 of the light emission period L (N-1).

Preferably, N is 4, and the following processing is performed: when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (4) is adjusted, the 1 st luminance D1(3) at the 2 nd switching timing in the light emission period K (3) is set as the information on the 2 nd switching timing T2 of the light emission period K (3)^*An adjustment coefficient Y (3) obtained by dividing the target luminance is multiplied by the light quantity of the 2 nd illumination light.

Preferably, the 2 nd processor performs at least any one of the following steps: a step of adjusting the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) using the information on the 2 nd switching timing T2 of the plurality of light emission periods K (N-Q) and the 1 st switching timing T1 of the plurality of light emission periods L (N-P) before the light emission period L (N), or a step of adjusting the light quantity of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) using the information on the 1 st switching timing T1 of the plurality of light emission periods L (N-Q) and the 2 nd switching timing T2 of the plurality of light emission periods K (N-P) before the light emission period K (N).

Preferably, let N be 6 and the 2 nd processor performsThe following treatment is carried out: when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (6) is adjusted, the 1 st luminance D1(5) according to the 2 nd switching timing T2 in the light emission period K (5)^*And 2 nd brightness D2(4) at 1 st switching timing T1 in the light-emitting period L (4)^*And multiplying the preset target brightness V by a specific adjustment coefficient Y with the light quantity of the 2 nd illumination light.

Preferably, the 1 st luminance or the 2 nd luminance is obtained from an average of pixel values other than blood vessels or lesions in the 1 st image signal or the 2 nd image signal. Preferably, the 1 st luminance or the 2 nd luminance is obtained from an average of pixel values of the 1 st image signal or the 2 nd image signal except for the abnormal pixels including at least one of the dark portion and the halo, or an average of pixel values of the 1 st image signal group or the 2 nd image signal group except for the 1 st image signal or the 2 nd image signal including the abnormal pixels. The 2 nd processor preferably performs the adjustment of the light quantity of the 2 nd illumination light or the adjustment of the light quantity of the 1 st illumination light only when the 1 st luminance or the 2 nd luminance is within a range of a predetermined target luminance range.

Effects of the invention

According to the present invention, when a plurality of lights are switched to illuminate, the light amount of illumination light of each light can be controlled in accordance with a change in an object.

Drawings

Fig. 1 is an external view of an endoscope system according to embodiment 1.

Fig. 2 is a block diagram showing functions of the endoscope system according to embodiment 1.

Fig. 3 is a graph showing emission spectra of violet light V, blue light B, green light G, and red light R.

Fig. 4 is a graph showing the emission spectrum of the 1 st illumination light including violet light V, blue light B, green light G, and red light R.

Fig. 5 is a graph showing the emission spectrum of the 2 nd illumination light including violet light V, blue light B, green light G, and red light R.

Fig. 6 is an explanatory view showing a light emission period of the 1 st illumination light and a light emission period of the 2 nd illumination light.

Fig. 7 is an explanatory diagram showing a light emission period setting menu.

Fig. 8 shows spectral transmittances of the B filter, the G filter, and the R filter provided in the image sensor.

Fig. 9 is an explanatory diagram for explaining acquisition of the 1 st image signal group and the 2 nd image signal group by time series.

Fig. 10 is a block diagram showing the functions of the DSP.

Fig. 11 is a block diagram showing the function of the special image processing section.

Fig. 12 is an image diagram showing the 1 st special observed image.

Fig. 13 is an explanatory diagram showing the violet and blue light images and the green and red light images obtained when the 1 st illumination light is illuminated.

Fig. 14 is an image diagram showing the 2 nd special observation image.

Fig. 15 is an explanatory diagram showing a violet light image and green and red light images obtained when the 2 nd illumination light is illuminated.

FIG. 16 is a graph showing a 2 nd luminance D2(2) for adjusting the light quantity of the 2 nd illumination light^*The light emission period and the luminance of (1).

Fig. 17 is an explanatory diagram showing a relationship between luminance and light amount when an object is a standard.

Fig. 18 is an explanatory diagram showing a relationship between luminance and light amount when the object is not a standard time.

Fig. 19 is an explanatory diagram of a relationship between luminance and light amount when adjustment of the light amount is performed when the subject is not standard.

FIG. 20 is a view showing a display for adjusting the 2 nd luminance D2(2) of the 2 nd illumination light^*And 2 nd brightness D2(4)^*The light emission period and the luminance of (1).

FIG. 21 shows a display for adjusting the 1 st luminance D1(3) of the 2 nd illumination light^*The light emission period and the luminance of (1).

FIG. 22 shows a graph showing a 2 nd luminance D2(3) for adjusting the light quantity of the 2 nd illumination light^*And brightness D1(5)^*The light emission period and the luminance of (1).

Detailed Description

[ embodiment 1 ]

As shown in fig. 1, the endoscope system 10 according to embodiment 1 includes an endoscope 12, a light source device 14, a processor device 16, a display 18 (display unit), and a user interface 19. Endoscope 12 is optically connected to light source device 14 and electrically connected to processor device 16. The endoscope 12 includes an insertion portion 12a to be inserted into the subject, an operation portion 12b provided at a proximal end portion of the insertion portion 12a, and a bending portion 12c and a distal end portion 12d provided at a distal end side of the insertion portion 12 a. By operating the corner piece knob 12e of the operating portion 12b, the bending portion 12c performs a bending operation. The distal end portion 12d is oriented in a desired direction in accordance with the bending operation. The user interface 19 includes a mouse and the like in addition to the illustrated keyboard.

The operation unit 12b is provided with a mode switching SW13a and a still image acquisition command unit 13b in addition to the bending knob 12 e. The mode switching SW13a is used for switching operation of the normal light observation mode, the 1 st special light observation mode, the 2 nd special light observation mode, and the multi-observation mode. The normal light observation mode is a mode in which a normal image is displayed on the display 18. The 1 st special light observation mode is a mode in which a 1 st special observation image in which surface layer information of surface layer blood vessels and the like is emphasized is displayed on the display 18. The 2 nd special light observation mode is a mode in which a 2 nd special observation image in which deep layer information of a deep blood vessel and the like is emphasized is displayed on the display 18. The multi-view mode is a mode in which the 1 st special observation image (hereinafter, referred to as the 1 st image) and the 2 nd special observation image (hereinafter, referred to as the 2 nd image) are automatically switched and displayed on the display 18. In addition, in order to switch the mode, a foot switch or the like may be used in addition to the mode switching SW13 a.

The processor device 16 is electrically connected to the display 18 and the user interface 19. The display 18 outputs display image information and the like. The user interface 19 functions as a UI (user interface) for receiving input operations such as function setting. The processor device 16 may be connected to an external recording unit (not shown) for recording image information and the like.

As shown in fig. 2, the light source device 14 includes a light source unit 20, a light source control unit 21, an optical path coupling unit 23, and a light emission period setting unit 24. The light source section 20 includes a V-LED (violet light Emitting Diode) 20a, a B-LED (blue light Emitting Diode) 20B, a G-LED (green light Emitting Diode) 20c, and an R-LED (red light Emitting Diode) 20 d. In the light source device 14, programs related to various controls are assembled in a program memory (not shown). The light source control unit 21 including the 1 st processor realizes the function of the light source control unit 21 by executing a program incorporated in a program memory. Specifically, the light source control unit 21 functions to control the driving of the LEDs 20a to 20 d. The light path coupling section 23 couples light paths of the four colors of light emitted from the four color LEDs 20a to 20 d. The light coupled by the optical path coupling portion 23 is irradiated into the subject via the light guide 41 and the illumination lens 45 penetrating the insertion portion 12 a. In addition, an LD (Laser Diode) may be used instead of the LED. The light emission period setting unit 24 sets each light emission period of the plurality of illumination lights.

As shown in FIG. 3, the V-LED20a generates violet light V with a central wavelength of 405 + -10 nm and a wavelength range of 380-420 nm. The B-LED20B generates blue light B with a central wavelength of 460 + -10 nm and a wavelength range of 420-500 nm. The G-LED20c generates green light G with a wavelength range of 480-600 nm. The R-LED20d generates red light R with a central wavelength of 620-630 nm and a wavelength of 600-650 nm.

The light source controller 21 controls the V-LED20a, the B-LED20B, the G-LED20c, and the R-LED20 d. In the normal light observation mode, the light source controller 21 controls the LEDs 20a to 20d so as to emit normal light having a light intensity ratio of Vc: Bc: Gc: Rc among the violet light V, blue light B, green light G, and red light R.

In the 1 st special light observation mode, the light source control unit 21 controls the LEDs 20a to 20d so as to emit 1 st illumination light in which the light intensity ratio among the violet light V, blue light B, green light G, and red light R becomes Vs 1: Bs 1: Gs 1: Rs 1. The light intensity ratio Vs 1: Bs 1: Gs 1: Rs1 corresponds to the light quantity condition of the 1 st illumination light. The 1 st illumination light preferably emphasizes superficial blood vessels. Therefore, the 1 st illumination light is preferably such that the light intensity of the violet light V is greater than the light intensity of the blue light B. For example, as shown in fig. 4, the ratio of the light intensity Vs1 of the violet light V to the light intensity Bs1 of the blue light B is set to "4: 1".

In addition, in the present specification, the light intensity ratio includes a case where the ratio of at least 1 semiconductor light source is 0 (zero). Therefore, the case where any one or 2 or more semiconductor light sources are not lit is included. For example, as in the case where the light intensity ratio between the violet light V, blue light B, green light G, and red light R is 1: 0, only 1 of the semiconductor light sources is turned on, and the other 3 are not turned on.

In the 2 nd special light observation mode, the light source control unit 21 controls the LEDs 20a to 20d so as to emit the 2 nd illumination light in which the light intensity ratio of the violet light V, blue light B, green light G, and red light R becomes Vs2, Bs2, Gs2, Rs 2. The light intensity ratio Vs 2: Bs 2: Gs 2: Rs2 corresponds to the light quantity condition of the 2 nd illumination light. The 2 nd illumination light preferably emphasizes deep blood vessels. Therefore, the 2 nd illumination light is preferably such that the light intensity of the blue light B is greater than the light intensity of the violet light V. For example, as shown in fig. 5, it is preferable to set the ratio of the light intensity Vs2 of the violet light V to the light intensity Bs2 of the blue light B to "1: 3".

When the multi-observation mode is set, the light source control section 21 performs control of emitting the 1 st illumination light and the 2 nd illumination light in the light emission period k (n) and the light emission period l (n), respectively, and automatically switching to emit the 1 st illumination light and the 2 nd illumination light. The light-emitting period K (N) and the light-emitting period L (N) each have a light-emitting period of at least 1 frame or more. In addition, N is a natural number, and the larger N becomes, the more advanced the time is represented.

More specifically, for example, as shown in fig. 6, when the light emission period K (n) is 4 frames and the light emission period K (n) is 4 frames, the light source control unit 21 continuously emits the 1 st illumination light of 4 frames in the light emission period K (1), and then continuously emits the 2 nd illumination light of 4 frames in the light emission period L (2). Then, this light emission pattern is repeated.

The "frame" is a unit for controlling the image sensor 48 (see fig. 2) for capturing an observation target, and for example, the "1 frame" is a period including at least an exposure period during which the image sensor 48 is exposed to light from the observation target and a reading period during which an image signal is read. In the present embodiment, the light emission period k (n) or the light emission period l (n) is defined in correspondence with a "frame" which is a unit of imaging.

The light emission period k (n) and the light emission period l (n) can be appropriately changed by the light emission period setting unit 24 connected to the light source control unit 21. When the operation of changing the light emission period is received by the operation of the user interface 19, the light emission period setting unit 24 displays a light emission period setting menu shown in fig. 7 on the display 18. The light emission period k (n) can be changed, for example, between 2 frames and 10 frames. Each light emission period is assigned to the slide bar 26 a.

When the light emission period k (n) is changed, the slider 27a is engaged with the position on the slide bar 26a indicating the light emission period desired to be changed by operating the user interface 19, and the light emission period k (n) is changed. As for the light emission period k (n), the light emission period l (n) is also changed by operating the user interface 19 to move the slider 27b to a position indicating a light emission period desired to be changed on the slide bar 26b (for example, a light emission period of 2 to 10 frames is allocated).

As shown in fig. 2, the light guide 41 is built in the endoscope 12 and a universal cord (a cord connecting the endoscope 12, the light source device 14, and the processor device 16), and transmits the light coupled by the optical path coupling portion 23 to the distal end portion 12d of the endoscope 12. Further, a multimode optical fiber can be used as the light guide 41. For example, an optical fiber cable having a core diameter of 105 μm, a cladding diameter of 125 μm, and a small diameter of 0.3 to 0.5mm including a protective layer serving as a sheath can be used.

An illumination optical system 30a and an imaging optical system 30b are provided at the distal end portion 12d of the endoscope 12. The illumination optical system 30a has an illumination lens 45, and light from the light guide 41 is irradiated to the observation target via this illumination lens 45. The imaging optical system 30b includes an objective lens 46 and an imaging sensor 48. The reflected light from the observation target enters the image sensor 48 via the objective lens 46. Thereby, a reflected image of the observation target is formed on the imaging sensor 48.

The image sensor 48 is a color image sensor, and captures a reflected image of the subject to output an image signal. The image sensor 48 is preferably a CCD (charge coupled device) image sensor, a CMOS (complementary metal-oxide semiconductor) image sensor, or the like. The image sensor 48 used in the present invention is a so-called RGB image sensor including R pixels provided with R filters, G pixels provided with G filters, and B pixels provided with B filters, which is a color image sensor for obtaining RGB image signals of three colors of R (red), G (green), and B (blue).

As shown in fig. 8, the B filter 48B transmits light on the short wavelength side among light in the violet band, light in the blue band, and light in the green band. The G filter 48G transmits light of the green band, light of the blue band on the long wavelength side, and light of the red band on the short wavelength side. The R filter 48R transmits light in the red band and light on the short-wavelength side of the green band. Therefore, in the imaging sensor 48, the B pixel has sensitivity to the violet light V and the blue light B, the G pixel has sensitivity to the blue light B, the green light G, and the red light R, and the R pixel has sensitivity to the green light G and the red light R.

Instead of the RGB color image sensor, the image sensor 48 may be a so-called complementary color image sensor including complementary color filters of C (cyan), M (magenta), Y (yellow), and G (green). When a complementary color image sensor is used, image signals of four colors of CMYG are output, and therefore, it is necessary to convert the image signals of four colors of CMYG into image signals of three colors of RGB by complementary color-primary color conversion. The image sensor 48 may be a monochrome image sensor provided with no color filter. In this case, the light source control section 21 needs to turn on the blue light B, the green light G, and the red light R in time division, and adds a synchronization process to the processing of the image pickup signal.

As shown in fig. 2, an image signal output from the image pickup sensor 48 is sent to a CDS/AGC circuit 50. The CDS/AGC circuit 50 performs Correlated Double Sampling (CDS) (correlated Double sampling) or Automatic Gain Control (AGC) (auto Gain control) on an image signal as an analog signal. The image signal having passed through the CDS/AGC circuit 50 is converted into a Digital image signal by an a/D converter (a/D (Analog/Digital) converter) 51. The digital image signal subjected to the a/D conversion is input to the processor device 16.

In the processor device 16, programs related to various processes and controls are assembled in a program memory (not shown). The Processor device 16 realizes the functions of the image acquisition unit 52, the DSP (Digital Signal Processor) 54, the noise removal unit 58, the Signal switching unit 60, the normal observation image processing unit 62, the special observation image processing unit 63, the display control unit 64, the still image storage unit 65, and the still image storage control unit 66 by executing a program incorporated in a program memory by a central control unit (not shown) in the Processor device 16 including the 2 nd Processor. The functions of the luminance calculation section 55, the light amount setting section 56, and the set light amount adjustment section 57, which will be described later, included in the DSP54 are also realized in accordance with the execution of the program.

The image acquisition unit 52 acquires an observation image obtained by imaging an observation target in the endoscope 12. Specifically, as an observation image, a digital color image signal from the endoscope 12 is input to the image acquisition section 52. The color image signal is composed of a red signal output from the R pixel of the image sensor 48, a green signal output from the G pixel of the image sensor 48, and a blue signal output from the B pixel of the image sensor 48.

As shown in fig. 9, the image acquiring unit 52 acquires the 1 st image signal group during the light emission period k (n). The 1 st image signal group includes a plurality of 1 st image signals SP1 obtained by capturing an object illuminated with the 1 st illumination light in the light emission period k (n). The image acquiring unit 52 acquires the 2 nd image signal group during the light emission period l (n). The 2 nd image signal group includes a plurality of 2 nd image signals SP2 obtained by capturing an object illuminated with the 2 nd illumination light in the light emission period l (n). In the present embodiment, when the multi-observation mode is set, the light source control section 21 emits the 1 st illumination light and the 2 nd illumination light in the light emission period k (n) and the light emission period l (n), respectively, and performs control of automatically switching the 1 st illumination light and the 2 nd illumination light to emit them, so that the image acquisition section 52 periodically acquires images in the order of the 1 st image signal group and the 2 nd image signal group with the elapse of time.

Since the light-emission period k (n) and the light-emission period l (n) each have a light-emission period of at least 1 frame or more, the 1 st image signal group and the 2 nd image signal group include at least 1 or more of the 1 st image signal SP1 and the 2 nd image signal SP2, respectively. In this embodiment, the light-emission period k (n) and the light-emission period l (n) are both 4-frame light-emission periods. Therefore, the 1 st image signal group including the 41 st image signals SP1 is acquired in the light emission period k (n), and the 2 nd image signal group including the 42 nd image signals SP2 is acquired in the light emission period l (n).

The DSP56 performs various signal processes such as a defect correction process, an offset process, a white balance process, a linear matrix process, a gamma conversion process, and a demosaic process on the received image signal. As shown in fig. 10, the DSP54 includes a luminance calculation unit 55, a light amount setting unit 56, and a set light amount adjustment unit 57. Information on the light quantities of the normal light and the 1 st illumination light or the 2 nd illumination light obtained by the light quantity setting section 55 or the set light quantity adjusting section 56 is sent to the light source control section 21. The light source control section 21 controls the control of the light amounts of the normal light and the 1 st illumination light or the 2 nd illumination light based on the information on the light amount from the light amount setting section 55 or the set light amount adjusting section 56. The details of the luminance calculating section 55, the light amount setting section 56, and the set light amount adjusting section 57 will be described later.

In the defect correction processing, the signals of the defective pixels of the image sensor 48 are corrected. In the offset processing, a dark current component is removed from the image signal subjected to the defect correction processing, and an accurate zero level is set. The 1 st image signal is multiplied by a 1 st gain coefficient, and the 2 nd image signal is multiplied by a 2 nd gain coefficient to perform white balance processing in which the signal level is adjusted by multiplying the image signal after the offset processing by a gain. The image signal after the white balance processing is subjected to linear matrix processing for improving color reproducibility. Then, the brightness or chroma is adjusted by gamma conversion processing. The image signal after the linear matrix processing is subjected to demosaicing processing (also referred to as isotropic processing or synchronization processing), and a signal of a missing color in each pixel is generated by interpolation. By this demosaicing process, all pixels become to have signals of respective colors.

The denoising unit 58 removes noise from the image signal by performing denoising processing (for example, moving average method, median filtering method, or the like) on the image signal subjected to the gamma correction processing by the DSP 56. The noise-removed image signal is sent to the signal switching section 60.

When the normal light observation mode is set by the mode switching SW13a, the signal switching unit 60 transmits an image signal for normal light obtained by illumination and imaging of normal light to the normal observation image processing unit 62. As shown in fig. 11, the special observation image processing section 63 includes a 1 st special observation image processing section 67, a 2 nd special observation image processing section 68, and a detection section 69. When the 1 st special light observation mode is set, the 1 st image signal obtained by the illumination and imaging of the 1 st illumination light is sent to the 1 st special observation image processing section 67. The 1 st image signal includes a 1 st red signal output from the R pixel of the image sensor, a 1 st green signal output from the G pixel of the image sensor 48, and a 1 st blue signal output from the B pixel of the image sensor 48. When the 2 nd special light observation mode is set, the 2 nd image signal obtained by the illumination and imaging of the 2 nd illumination light is sent to the 2 nd special observation image processing section 63. The 2 nd image signal includes a 2 nd red signal output from the R pixel of the image sensor, a 2 nd green signal output from the G pixel of the image sensor 48, and a 2 nd blue signal output from the B pixel of the image sensor 48. Also, in the case where the multi-observation mode is set, the 1 st image signal obtained by the illumination and photographing of the 1 st illumination light is sent to the 1 st special observation image processing section 67, and the 2 nd image signal obtained by the illumination and photographing of the 2 nd illumination light is sent to the 2 nd special observation image processing section 63.

The ordinary observation image processing section 62 performs image processing for an ordinary image on the RGB image signals obtained in the ordinary light observation mode. The image processing for the normal image includes structure emphasis processing for the normal image and the like. The normal observation image processing section 62 is provided with a parameter for a normal image to be multiplied by the RGB image signal to perform image processing for the normal image. The RGB image signals subjected to the image processing for the normal image are input as a normal image from the normal observation image processing section 62 to the display control section 64.

The 1 st special observation image processing unit 67 generates a 1 st image on the basis of the 1 st image signal, the 1 st image being subjected to image processing such as saturation enhancement processing, hue enhancement processing, and structure enhancement processing. In image 1, many superficial blood vessels are contained and the color of the background mucosa is also correctly reproduced. The 1 st special observation image processing section 67 is provided with a 1 st image parameter for multiplying the 1 st image signal to perform the image processing of the 1 st image. The 1 st special observation image processing unit 67 does not perform the superficial blood vessel enhancement processing for enhancing superficial blood vessels, but may perform the superficial blood vessel enhancement processing depending on the processing load.

As shown in fig. 12, an image showing the background mucosa BM and the superficial blood vessels VS1 in the observation target is displayed by the 1 st image. The 1 st image is obtained from the 1 st illumination light including violet light, blue light, green light, and red light. As shown in fig. 13, when the 1 st illumination light illuminates the observation target, the 1 st illumination light 1 illuminates the superficial layer where the violet light V and the blue light B enter the superficial blood vessels VS 1. Therefore, the violet light image VP obtained from the reflected light of the violet light V and the blue light B includes an image of the superficial blood vessels VS 1. Here, since the light intensity of the violet light V is stronger than that of the blue light B, the violet image VP is used. In the 1 st illumination light, the green light G and the red light R enter the background mucosa BM located deeper than the superficial blood vessel VS1 and the deep blood vessel VS2 (blood vessels located deeper than the superficial blood vessel VS 1). Therefore, the green and red light image GRP obtained from the reflected light of the green light G and the red light R includes an image of the background adhesive film BM. As described above, since the 1 st image is an image in which the violet light image VP and the green and red light images GRP are combined, the background mucosa BM and the superficial blood vessels VS1 are displayed.

The 2 nd special observation image processing unit 68 generates the 2 nd image on the basis of the 2 nd image signal, which has been subjected to image processing such as saturation enhancement processing, hue enhancement processing, and structure enhancement processing. In image 2, many deep blood vessels are contained and the color of the background mucosa is also correctly reproduced. The 2 nd special observation image processing section 68 is provided with a 2 nd image parameter for multiplying the 2 nd image signal to perform the image processing of the 2 nd image. In addition, the 2 nd special observation image processing unit 68 does not perform the superficial blood vessel enhancement processing for enhancing the deep blood vessels, but may perform the deep blood vessel enhancement processing depending on the processing load.

As shown in fig. 14, an image showing the background mucosa BM and the deep blood vessel VS2 in the observation target is displayed by the 2 nd image. The 2 nd image is obtained from the 2 nd illumination light including violet light, blue light, green light, and red light. As shown in fig. 15, when the 1 st illumination light illuminates the observation target, the 2 nd illumination light is such that the violet light V and the blue light B enter deep layers where the deep blood vessels VS2 are distributed. Therefore, the blue light image BP obtained from the reflected lights of the violet light V and the blue light B includes an image of the deep blood vessel VS 2. Here, the blue light image BP is used because the light intensity of the blue light B is stronger than the light intensity of the violet light V. In addition, the green light G and the red light R in the 2 nd illumination light reach the background mucosa BM located deeper than the superficial blood vessel VS1 and the deep blood vessel VS2 (blood vessels located deeper than the superficial blood vessel VS 1). Therefore, the green and red light image GRP obtained from the reflected light of the green light G and the red light R includes an image of the background adhesive film BM. As described above, since the 2 nd image is an image in which the blue light image BP and the green and red light images GRP are combined, the images of the background mucosa BM and the deep blood vessels VS2 are displayed.

As described above, in the present embodiment, it is preferable that the 1 st special observation image is generated from the 1 st image signal, and the 2 nd special observation image is generated from the 2 nd image signal, wherein the 1 st special observation image emphasizes the superficial blood vessels, and the 2 nd special observation image emphasizes the middle-deep blood vessels located at a position deeper than the superficial blood vessels.

The detector 69 detects a blood vessel or a lesion from the normal image, the 1 st image, and the 2 nd image. As described above, since the 1 st image is an image showing the superficial blood vessels VS1 and the 2 nd image is an image showing the deep blood vessels VS2, these blood vessels can be detected by image processing. In addition to the 1 st image and the 2 nd image, a blood vessel or a lesion can be detected by these image processing using a normal observation image. The detection unit 69 detects an abnormal portion in the 1 st image or the 2 nd image as an abnormal image signal. The detection result of the blood vessel or the lesion is sent to the white balance unit 55 or the light source control unit 21.

The display control unit 64 performs control for displaying the normal image, the 1 st image, and/or the 2 nd image input from the normal observation image processing unit 62 or the special observation image processing unit 63 as an image that can be displayed on the display 18. Images corresponding to the respective observation modes are displayed under control by the display control unit 64. In the case of the normal observation mode, a normal image is displayed on the display 18. In the 1 st special light observation mode, the 1 st image (see fig. 12) is displayed on the display 18. In the 2 nd special light observation mode, the 2 nd image (see fig. 14) is displayed on the display 18.

In the multi-observation mode, the 1 st and 2 nd color images are displayed on the display 18 in a manner switched in accordance with the light emission period of the 1 st illumination light and the light emission period of the 2 nd illumination light. That is, when the light emission period k (n) is 4 frames and the light emission period l (n) is 4 frames, the 1 st display observation image is displayed continuously for 4 frames and the 2 nd display observation image is displayed continuously for 4 frames.

As described above, in the multi-view mode, the 2 types of images 1 and 2 can be automatically switched and displayed without the operation of the mode switching SW13a by the user. In this manner, by automatically switching the display, the same observation target is displayed in the 1 st image and the 2 nd image as long as the observation target does not move or the distal end portion 12d of the endoscope 12 does not move. However, in the 1 st image and the 2 nd image, even if the observation target is the same, the observation target is different in state depending on the spectral information because the spectral information is different. That is, in the 1 st image, the visibility of the superficial blood vessels is improved, while in the 2 nd image, the visibility of the deep blood vessels is improved. Therefore, by switching between displaying the 1 st image and the 2 nd image, visibility of a plurality of blood vessels having different depths can be improved.

As shown in fig. 2, the still image saving control unit 66 performs control to save the image obtained at the timing of the still image acquisition command in the still image saving unit 65 as a still image, in accordance with the command from the still image acquisition command unit 13 b. In the case of the normal observation mode, the normal image obtained at the timing of the still image acquisition command is stored as a still image in the still image storage unit 65. In the 1 st special light observation mode, the 1 st special observation image obtained at the timing of the still image acquisition command is stored as a still image in the still image storage unit 65. In the case of the 2 nd special light observation mode, the 2 nd special observation image obtained at the timing of the still image acquisition command is stored as a still image in the still image storage unit 65. In the multi-view mode, 1 set of observation images for display of the 1 st and 2 nd special observation images obtained at the timing of the still image acquisition command is stored in the still image storage unit 65.

The details of the luminance calculating section 55, the light amount setting section 56, and the set light amount adjusting section 57 will be described below. In the case of the normal light observation mode, the luminance calculating section 55 calculates the luminance of the subject from the image signal obtained in the normal light observation mode. The light amount setting unit 56 sets the light amount of the normal light based on the calculated brightness of the subject. The light source control section 21 controls the light amount of the normal light based on the light amount of the normal light set by the light amount setting section 56.

In the 1 st special light observation mode, the luminance calculating section 55 calculates the 1 st luminance D1 of the object from the 1 st image signal. The light quantity setting unit 56 sets the light quantity of the 1 st illumination light according to the 1 st luminance D1. The light source control unit 21 controls the light amount of the 1 st illumination light based on the light amount of the 1 st illumination light set by the light amount setting unit 56. In the case of the 2 nd special light observation mode, the luminance calculating section 55 calculates the 2 nd luminance D2 of the object from the 2 nd image signal. The light quantity setting unit 56 sets the light quantity of the 2 nd illumination light according to the 2 nd brightness D2. The light source control unit 21 controls the light amount of the 2 nd illumination light based on the light amount of the 2 nd illumination light set by the light amount setting unit 56.

The luminance calculating unit 55 may calculate the 1 st luminance D1 or the 2 nd luminance D2 using the pixel values of the entire pixels of the 1 st image signal or the 2 nd image signal, or may calculate the 1 st luminance D1 or the 2 nd luminance D2 from the average of the pixel values of the 1 st image signal or the 2 nd image signal excluding blood vessels or lesions. The 1 st luminance D1 or the 2 nd luminance D2 may be obtained from an average of pixel values of the 1 st image signal or the 2 nd image signal excluding the abnormal pixels including any one of the dark portion and the halo. Further, the 1 st luminance D1 or the 2 nd luminance D2 may be found from an average value of pixel values of normal image signals other than the 1 st image signal or the 2 nd image signal including the abnormal pixel in the 1 st image signal group or the 2 nd image signal group.

In the multi-observation mode, as shown in fig. 16, when the 1 st illumination light is emitted in the light emission period K (1) and the light emission period K (3) of the 1 st illumination light, the 1 st luminances D1(1) and D2(3) are calculated from the 1 st image signal, and the light quantity of the 1 st illumination light is set based on the 1 st luminances (1) and D2(3), as in the 1 st special light observation mode. When the 2 nd illumination light is emitted in the light emission period L (2) and the light emission period L (4) of the 2 nd illumination light, the 2 nd luminances D2(2) and D2(4) are calculated from the 2 nd image signal in the same manner as in the 2 nd special light observation mode, and the light quantity of the 2 nd illumination light is set based on the 2 nd luminances D2(2) and D2 (4).

On the other hand, the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 for switching from the 1 st illumination light to the 2 nd illumination light is adjusted by the set light quantity adjusting section 57. Similarly, the light quantity of the 1 st illumination light set at the 2 nd switching timing T2 at which the 2 nd illumination light is switched to the 1 st illumination light is adjusted by the set light quantity adjusting section 57.

In embodiment 1, the light amount of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) is adjusted using the information on the 1 st switching timing T1 of the light emission period L (N-2) before the light emission period L (N), or the light amount of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) before the light emission period K (N) is adjusted using the information on the 2 nd switching timing T2 of the light emission period K (N-2) before the light emission period K (N).

Specifically, the set light amount adjusting section 57 adjusts the light amount of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (4) using the information on the 1 st switching timing T1 of the light emission period L (2) before the light emission period L (4), or adjusts the light amount of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (3) using the information on the 2 nd switching timing T2 of the light emission period K (1) before the light emission period K (3).

The light emission period K (N) of the 1 st illumination light and the light emission period L (N +1) of the 2 nd illumination light both include the 1 st switching timing T1, and correspond to both the light emission timing of the last frame of the light emission period K (3) and the light emission timing of the first frame of the light emission period L (4), for example, in the case of fig. 16. The light emission period L (N) of the 2 nd illumination light and the light emission period K (N +1) of the 1 st illumination light both include the 2 nd switching timing T2, and correspond to both the light emission timing of the last frame of the light emission period L (2) and the light emission timing of the first frame of the light emission period K (3), for example, in the case of fig. 16.

For example, when the light quantity of the 2 nd illumination light set by the light quantity setting section 56 at the 1 st switching timing T1 is adjusted in the light emission period L (4) of the 2 nd illumination light, the 2 nd luminance D2(2) at the 1 st switching timing T1 in the light emission period L (2) before the light emission period L (4) is determined^*And a preset target brightness V, and adjusting the light quantity by using an adjustment coefficient X (2).

The adjustment coefficient X (2) is preferably the target luminance V divided by the 2 nd luminance D2(2)^*And obtain (adjustment factor X (2) ═ V/D2(2)^*). That is, when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (4) is set as the light quantity H2(4), the light quantity H2(4) of the 2 nd illumination light with the adjusted light quantity is obtained by multiplying the adjustment coefficient X (2) by the light quantity H2(4)^*(H2(4)^*X (2) × H2 (4)). The light quantity of the 2 nd illumination light with the adjusted light quantity H2(4)^*Is sent to the light source control part 21, and the light source control part 21 is based onThe light quantity of the 2 nd illumination light with the adjusted light quantity H2(4)^*The light quantity of the 2 nd illumination light is controlled.

As described above, by adjusting the light amounts of the 2 illumination lights using the adjustment coefficient X, even when the subject is not standardized, such as when there is an individual difference or a disease such as inflammation, which is a difference in observation site, it is possible to perform appropriate light amount control according to the luminance of the subject. For example, as shown in fig. 17, when the subject is the standard, the light quantity of the 2 nd illumination light is increased to the light quantity value Hs by AE (Auto Exposure) control by the light source control section 21 as switching from the 1 st illumination light to the 2 nd illumination light, and the luminance can be made substantially the same in the light emission period K (1) of the 1 st illumination light and the light emission period L (2) of the 2 nd illumination light.

On the other hand, when the subject is not the standard, for example, when the reflectance of the subject with respect to green light is high, as shown in fig. 18, when the light quantity of the 2 nd illumination light is increased to the light quantity value Hs by AE (Auto Exposure) control by the light source control section 21 as switching from the 1 st illumination light to the 2 nd illumination light, the luminance is changed at the 1 st switching timing T1 at which the light emission period K (1) is switched to the light emission period L (2) as shown in the present embodiment unless the light quantity adjustment of the 2 nd illumination light using the information (adjustment coefficient X (2)) related to the 1 st switching timing T1 is performed. This may be caused by the high reflectance of the green band of the subject, unlike the standard subject. However, in the light emission period L (2), after the first frame, the luminance converges to an appropriate luminance by AE control. Further, the luminance may vary at the 2 nd switching timing T2 when switching from the light emission period L (2) to the light emission period K (3) as described above.

Therefore, in the case where the subject is not the standard, in order to suppress the variation in the light quantity at the 1 st switching timing T1 or the 2 nd switching timing T2, as shown in fig. 19, the light quantity of the 2 nd illumination light is adjusted using the information (adjustment coefficient X (2)) on the 1 st switching timing T1 during the light emission period L (4). Then, the light quantity H2(4) is adjusted according to the light quantity^*By illuminating the 2 nd illumination light, the light emission period K (3) and the light emission period can be set to be shorter while suppressing the variation in the light quantity at the 1 st switching timing T1The luminance in the period L (4) is substantially the same.

Further, the light amount of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) may be adjusted using the information on the 1 st switching timing T1 of the plurality of light emission periods L (N-P) before the light emission period L (N), or the light amount of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) before the light emission period K (N) may be adjusted using the information on the 2 nd switching timing T2 of the light emission period K (N-P) before the light emission period K (N). In addition, P is set to an even number smaller than N.

For example, as shown in FIG. 20, when the light quantity of the 2 nd illumination light set by the light quantity setting section 56 at the 1 st switching timing T1 in the light emission period L (6) of the 2 nd illumination light is adjusted, the 2 nd luminance D2(4) at the 1 st switching timing T1 according to the light emission period L (4) before the light emission period L (6) is used^*And 2 nd luminance D2(2) at 1 st switching timing T1 in the light-emitting period L (2)^*And adjusting the target brightness V by using a specific adjustment coefficient X. Here, the specific adjustment coefficient X is preferably obtained by dividing the target luminance V by the pair 2 nd luminance D2(4)^*And 2 nd brightness D2(2)^*Each of the values is obtained by multiplying a weighting coefficient by the sum (specific adjustment coefficient X ═ V/(α 1 × D2 (4))^*+α2×D2(2)^*). However, α 1 and α 2 are weighting coefficients, and α 1+ α 2 is 1.

When the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (6) is set as the light quantity H2(6), the light quantity H2(6) of the 2 nd illumination light with the adjusted light quantity is obtained by multiplying the light quantity H2(6) by a specific adjustment coefficient X^*(H2(6)^*X × H26). The light quantity of the 2 nd illumination light with the adjusted light quantity H2(6)^*Is sent to the light source control part 21, and the light source control part 21 adjusts the light quantity according to the light quantity H2(6) of the 2 nd illumination light^*The light quantity of the 2 nd illumination light is controlled.

Further, the light quantity H2(N) obtained by adjusting the light quantity H2(N) of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) is obtained^*In this case, the following generalized formula A) can be used.

Formula A)

H2(N)^*Becoming (target brightness)

X (2 nd luminance D2(N-2) + α 2 at 1 st switching timing T1 of α 1/(emission period L (N-2))/(2 nd luminance D2(N-4) + … … + α N at 1 st switching timing T1 of emission period L (N-4))/(2 nd luminance D2(N-N) at 1 st switching timing T1 of emission period L (N-N))

Wherein α 1+ α 2+ … … α n is 1. And N is an even number less than N.

[ 2 nd embodiment ]

In embodiment 2, the light amount of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) is adjusted using the information on the 2 nd switching timing T2 of the light emission period K (N-1) before the light emission period L (N) or the light amount of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) before the light emission period K (N) is adjusted using the information on the 1 st switching timing T1 of the light emission period L (N-1) before the light emission period K (N).

For example, as shown in FIG. 20, when the light quantity of the 2 nd illumination light set by the light quantity setting section 56 is adjusted at the 1 st switching timing T1 of the light emission period L (4) of the 2 nd illumination light, the 1 st luminance D1(3) at the 2 nd switching timing T2 in the light emission period K (3) before the light emission period L (4)^*And a preset target brightness V, and adjusting the light quantity by using an adjustment coefficient Y (3). Here, the adjustment coefficient Y (3) is preferably obtained by dividing the target luminance V by 1 luminance D1(3)^*And obtain (adjustment coefficient Y (3) ═ V/D1(3)^*)。

That is, when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (4) is set as the light quantity H2(4), the light quantity H2(4) of the 2 nd illumination light with the adjusted light quantity is obtained by multiplying the adjustment coefficient Y (3) by the light quantity H2(4)^*(H2(4)^*Y (3) × H2 (4)). The light quantity of the 2 nd illumination light with the adjusted light quantity H2(4)^*Is sent to the light source control part 21, and the light source control part 21 adjusts the light quantity according to the light quantity H2(4) of the 2 nd illumination light^*The light quantity of the 2 nd illumination light is controlled.

The 2 nd processor may adjust the light amount of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) using the information on the 2 nd switching timing T2 of the plurality of light emission periods K (N-Q) and the 1 st switching timing T1 of the plurality of light emission periods L (N-P) before the light emission period L (N), or may adjust the light amount of the 1 st illumination light set at the 2 nd switching timing T2 of the light emission period K (N) using the information on the 1 st switching timing T1 of the plurality of light emission periods L (N-Q) and the 2 nd switching timing T2 of the plurality of light emission periods K (N-P) before the light emission period K (N). In addition, P is an even number smaller than N, and Q is an odd number smaller than N.

For example, as shown in FIG. 22, when the light quantity of the 2 nd illumination light set by the light quantity setting section 56 is adjusted at the 1 st switching timing T1 in the light emission period L (6) of the 2 nd illumination light, the 1 st luminance D1(5) at the 2 nd switching timing T2 in the light emission period K (5) before the light emission period L (6) is used^*And 2 nd brightness D2(4) at 1 st switching timing T1 in the light-emitting period L (4)^*And adjusting the light quantity by using a preset target brightness V and a specific adjusting coefficient Y.

Here, the specific adjustment coefficient Y is preferably to be adjusted to the 1 st luminance D1(5)^*A value obtained by dividing a value obtained by multiplying the target luminance V by the weighting coefficient beta, and a value obtained by multiplying the target luminance V by the 2 nd luminance D2(4)^*The values multiplied by the weighting coefficient α and the target luminance V are added (specific adjustment coefficient Y ═ β × D1(5)^*/V+α×D2(4)^*X V). Where α and β are weighting coefficients, and α + β is 1.

Further, when the light quantity of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (6) is set as the light quantity H2(6), the light quantity H2(6) of the 2 nd illumination light with the adjusted light quantity is obtained by multiplying the light quantity H2(6) by the specific adjustment coefficient Y^*(H2(6)^*Y × H26). The light quantity of the 2 nd illumination light with the adjusted light quantity H2(6)^*Is sent to the light source control part 21, and the light source control part 21 adjusts the light quantity according to the light quantity H2(6) of the 2 nd illumination light^*The light quantity of the 2 nd illumination light is controlled.

Further, the light quantity H2(N) obtained by adjusting the light quantity H2(N) of the 2 nd illumination light set at the 1 st switching timing T1 of the light emission period L (N) is obtained^*In this case, the following generalized formula B) can be used.

Formula B)

H2(N)^*＝

1/(target brightness)

(β 1/(1 st luminance D1(N-1) + β 2 at the 2 nd switching timing T2 in the emission period K (N-1))/(1 st luminance D1(N-3) + … … + β N at the 2 nd switching timing T2 in the emission period K (N-3))/(2 nd luminance D2(N-m) at the 1 st switching timing T1 in the emission period (N-m))

+ (target Brightness)

X (2 luminance D2(N-2) + α 2 at 1 st switching timing T1 in α 1/(emission period L (N-2))/(2 luminance D2(N-4) + … … + α N at 1 st switching timing T1 in emission period L (N-4))/(2 luminance D2(N-N) at 1 st switching timing T1 in emission period (N-N))

Wherein α 1+ α 2+ … … α n is 1, and β 1+ β 2+ … … + β n is 1. N is an even number smaller than N, and m is an odd number smaller than N.

In the above-described embodiments 1 and 2, the light quantity of the 2 nd illumination light at the 1 st switching timing T1 is always adjusted and the light quantity of the 1 st illumination light at the 2 nd switching timing T2 is adjusted in the multi-observation mode, but only when the 1 st luminance D1 or the 2 nd luminance is within the predetermined target luminance range, the light quantity of the 2 nd illumination light at the 1 st switching timing T1 may be adjusted and the light quantity of the 1 st illumination light at the 2 nd switching timing T2 may be adjusted.

For example, as shown in fig. 16, it is preferable that the 2 nd luminance D2(2) is adjusted when the light quantity of the 2 nd illumination light set by the light quantity setting section 56 at the 1 st switching timing T1 in the light emission period L (4) of the 2 nd illumination light^*In the range of the target luminance, the light quantity of the 2 nd illumination light at the 1 st switching timing T1 is not adjusted, and when the 2 nd luminance D2(2)^*When the range of the target luminance is out, the light quantity of the 2 nd illumination light at the 1 st switching timing T1 is adjusted.

In the above-described embodiment, the hardware configuration of the processing unit (processing unit) included in the processor device 16, such as the image acquisition unit 52, the DSP54, the noise removal unit 58, the normal observation image processing unit 62, the special observation image processing unit 63, the display control unit 64, the still image storage unit 65, and the still image storage control unit 66, is various processors (processors) as shown below. The various processors include a CPU (central Processing Unit), which is a general-purpose processor that executes software (program) and functions as various Processing units, a Programmable Logic Device (PLD), such as an FPGA (field programmable gate array), which can be manufactured with a circuit configuration changed, a GPU (graphic Processing Unit), a processor having a circuit configuration designed specifically for executing various processes, a dedicated electric circuit, and the like.

One processing unit may be constituted by one of these various processors, or may be constituted by a combination of two or more processors of the same kind or different kinds (for example, a plurality of FPGAs, a combination of a CPU and an FPGA, and a combination of a CPU and a GPU). Further, the plurality of processing units may be configured by one processor. As an example in which a plurality of processing units are configured by one processor, the 1 st embodiment is a system in which one processor is configured by a combination of one or more CPUs and software, as typified by a computer such as a client or a server, and functions as a plurality of processing units. The 2 nd System uses a processor in which the functions of the entire System including a plurality of processing units are realized by one IC (Integrated Circuit) Chip, as represented by a System On Chip (SoC) or the like. In this manner, the various processing units are configured using one or more of the various processors as a hardware configuration.

More specifically, the hardware configuration of these various processors is an electric circuit (circuit) in a system in which circuit elements such as semiconductor elements are combined.

The present invention can be applied to a processor device incorporated in a capsule endoscope system or various medical image processing devices, in addition to the processor device incorporated in the endoscope system according to embodiment 1 or 2.

Description of the symbols

10-endoscope system, 12-endoscope, 12 a-insertion section, 12B-operation section, 12 c-bending section, 12 d-tip section, 12 e-angle knob, 13 a-mode switching SW, 13B-still image acquisition command section, 14-Light source device, 16-processor device, 18-display, 19-user interface, 20-Light source section, 20a-V-LED (Violet Light Emitting Diode), 20B-B-LED (Blue Light Emitting Diode: Blue Light Emitting Diode), 20c-G-LED (Green Light Emitting Diode: Green Light Emitting Diode), 20d-R-LED (Red Light Emitting Diode: Red Light Emitting Diode), 21-Light source control section, 23-optical path combining section, 24-light emission period setting section, 26 a-slide bar, 26B-slide bar, 27 a-slide block, 27B-slide block, 30 a-illumination optical system, 30B-image pickup optical system, 41-light guide, 45-illumination lens, 46-objective lens, 48-image pickup sensor, 48B-B filter, 48G-G filter, 48R-R filter, 50-CDS/AGC circuit, 52-image acquisition section, 54-DSP (Digital Signal Processor), 55-brightness calculation section, 56-light quantity setting section, 57-set light quantity adjusting section, 58-noise removal section, 60-Signal switching section, 62-ordinary observation image processing section, 63-special observation image processing section, 64-display control section, 65-still image storage section, 66-still image storage control section, 67-1 st special observation image processing section, 68-2 nd special observation image processing section, 69-detection section, SP 1-1 st special observation image (1 st image), SP 2-2 nd special observation image (2 nd image), VP-purple light image, GRP-green and red light image, VS 1-superficial blood vessel, VS 2-medial blood vessel, BM-background mucosa.