WO2016189629A1

WO2016189629A1 - Endoscope system and method for controlling endoscope system

Info

Publication number: WO2016189629A1
Application number: PCT/JP2015/064958
Authority: WO
Inventors: 田中　良典; 真博西尾
Original assignee: オリンパス株式会社
Priority date: 2015-05-25
Filing date: 2015-05-25
Publication date: 2016-12-01
Also published as: JPWO2016189629A1; JP6736550B2

Abstract

This endoscope system (10) includes: an illumination unit (20); an imaging unit (40); a determination unit (63) that determines a region of interest (201) which is a region of interest for observation on the basis of a captured image of a subject imaged by the imaging unit (40); and a specification unit (65) that specifies an illuminated region (203) which is a region illuminated by an illumination light on the basis of the captured image. The endoscope system (10) further includes: a setting unit (67) that sets a predetermined illumination region (205) which is region to be illuminated with the illumination light on the basis of the region of interest (201) and the illuminated region (203); and an adjustment mechanism (70) that adjusts the optical properties of the illumination light so that the predetermined illumination region (205) will be illuminated with the illumination light.

Description

Endoscope system and control method of endoscope system

The present invention relates to an endoscope system and an endoscope system control method.

For example, Patent Document 1 discloses an endoscope having an elongated insertion portion. The insertion unit includes a light guide that transmits light emitted from the light source, and an illumination optical system that is disposed in front of the light emission end of the light guide and includes an illumination lens group. The illumination lens group has at least one optical element. The optical element has an inclined surface facing the emission end face of the light guide and inclined with respect to the emission end face.

Even in the case where a light guide having a small NA such as a quartz light guide is used in a thin endoscope having a wide viewing angle, the periphery of the field of view is sufficiently illuminated by the optical element.

JP-A-8-286125

In the endoscope, the illumination area of the illumination light is fixed in advance. For this reason, if the illumination area of the illumination light is set to be narrow in advance corresponding to a narrow viewing angle, when the viewing angle becomes wide according to the observation, the attention area that is the area of interest for observation is more than the illumination area. The attention area includes the illumination area. In this case, there is a possibility that the illumination light cannot be sufficiently distributed to the planned illumination area that exists inside the attention area and outside the illumination area and is planned to be illuminated with illumination light.
On the other hand, if the illumination area of the illumination light is set to be wide in advance corresponding to a wide viewing angle, when the viewing angle becomes narrow according to observation, the illumination area becomes larger than the attention area, and the illumination area is focused. Contains the area. In this case, the region that exists inside the illumination region and outside the region of interest and is illuminated with illumination light is a region where illumination light is illuminated wastefully.
For this reason, the illumination light cannot be sufficiently distributed according to the viewing angle, and the illumination light is wasted.
It is desired that illumination light can be sufficiently distributed without being affected by the viewing angle, and that waste of illumination light is suppressed.

The present invention has been made in view of these circumstances, and an object thereof is to provide an endoscope system and an endoscope system control method that can suppress the waste of illumination light regardless of the viewing angle.

One aspect of the endoscope system of the present invention is an imaging unit that illuminates a subject with illumination light, an imaging unit that images the subject based on the illumination light reflected from the subject, and an image taken by the imaging unit. An attention area determination unit that determines an attention area that is an area of interest for observation based on a captured image of the subject and an illumination area that is illuminated by the illumination light are identified based on the captured image An illumination area specifying unit, an illumination scheduled area setting unit for setting an illumination scheduled area that is an area where illumination of the illumination light is scheduled based on the attention area and the illumination area, and the illumination scheduled area is the An adjustment mechanism for adjusting the optical characteristics of the illumination light so that the illumination light is illuminated.

One aspect of the control method of the endoscope system according to the present invention includes an illumination step of emitting illumination light from an illumination unit to illuminate the subject with the illumination light, and the subject on the basis of the illumination light reflected from the subject. An imaging step of imaging by the imaging unit, a specifying step of specifying an illumination region, which is a region illuminated by the illumination light, by an illumination region specifying unit based on a captured image of the subject imaged by the imaging unit, Based on the captured image, a determination step of determining an attention area that is an area of interest for observation by an attention area determination unit, and illumination of the illumination light is scheduled based on the attention area and the illumination area. A setting step of setting a planned illumination area, which is a target area, by the planned illumination area setting unit; and an optical mechanism for adjusting the optical characteristics of the illumination light so that the planned illumination area is illuminated with the illumination light. It includes an adjustment step of adjusting me.

According to the present invention, it is possible to provide an endoscope system and an endoscope system control method capable of suppressing the waste of illumination light regardless of the viewing angle.

FIG. 1A is a schematic diagram of an endoscope system according to the first embodiment of the present invention. FIG. 1B is a diagram illustrating a configuration of an illumination unit and an adjustment mechanism. FIG. 1C is a front view of the distal end portion of the insertion portion. FIG. 2A is a diagram illustrating that a planned illumination area is set in a state where the attention area is larger than the illumination area and the attention area includes the illumination area. FIG. 2B is a diagram illustrating that illumination light is illuminated on the planned illumination area illustrated in FIG. 2A. FIG. 2C is a diagram illustrating that the illumination planned area is set in a state where the illumination area is larger than the attention area and the illumination area includes the attention area. FIG. 2D is a diagram illustrating that the illumination light is illuminated on the planned illumination area illustrated in FIG. 2C. FIG. 3A is a diagram for explaining the principle of adjusting the light distribution. FIG. 3B is a diagram for explaining the principle of adjusting the light distribution. FIG. 4 is a flowchart illustrating an operation of adjusting the light distribution in the first embodiment. FIG. 5 is a flowchart showing an operation for adjusting the light distribution in the modification of the first embodiment. FIG. 6A is a diagram illustrating a configuration of an illumination unit, an adjustment mechanism, and a light distribution adjustment illumination unit according to the second embodiment of the present invention. FIG. 6B is a diagram illustrating a state in which the relative distance between the illumination unit and the optical element of the light distribution adjusting illumination unit is shortened, and illumination light is emitted with wide light distribution. FIG. 6C is a diagram illustrating a state in which the relative distance between the illumination unit and the optical element of the light distribution adjusting illumination unit is increased, and illumination light is emitted with a narrow light distribution. FIG. 6D is a diagram illustrating a region of interest according to the second embodiment. FIG. 6E is a flowchart showing an operation of adjusting the light distribution in the second embodiment. FIG. 7A is a diagram illustrating a configuration of an illumination unit and an adjustment mechanism according to the third embodiment of the present invention. FIG. 7B is a diagram illustrating the illumination unit inclined by the adjustment mechanism. FIG. 7C is a diagram illustrating a positional relationship among a region of interest, an illumination region, and a planned illumination region in a state before the illumination unit is tilted. FIG. 7D is a diagram illustrating a positional relationship among a region of interest, an illumination region, and a planned illumination region in a state after the illumination unit is tilted. FIG. 7E is a flowchart illustrating an operation of adjusting the light distribution in the third embodiment. FIG. 8A is a schematic view of an endoscope system according to the fourth embodiment of the present invention. FIG. 8B is a diagram illustrating a positional relationship among a region of interest, an illumination region, and an illumination scheduled region before the light amount is adjusted. FIG. 8C is a diagram illustrating a positional relationship among the attention area, the illumination area, and the illumination scheduled area in a state after the light amount is adjusted. FIG. 8D is a flowchart illustrating an operation of adjusting the light distribution in the fourth embodiment. FIG. 9 is a flowchart showing an operation of adjusting the light distribution in the fifth embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in some drawings, illustration of some of the members is omitted for clarity of illustration.

[First Embodiment]
[Constitution]
The first embodiment will be described with reference to FIGS. 1A, 1B, 1C, 2A, 2B, 2C, 2D, 3A, 3B, and 4. FIG.
As shown in FIG. 1A, an endoscope system 10 includes an illumination unit 20 that illuminates a subject 13 with illumination light IL from a distal end portion 11 of an insertion portion that is provided in an endoscope (not shown), and a reflection that is reflected from the subject 13. An imaging unit 40 that images the subject 13 based on the illumination light IL that is the light RL. The endoscope system 10 includes a display unit 50 that displays a captured image 301 (see FIGS. 2A, 2B, 2C, and 2D) captured by the imaging unit 40.

[Lighting unit 20]
As shown in FIG. 1A, the illumination unit 20 includes a light source 21 that emits primary light, a light source control unit 23 that controls the light source 21, a plurality of light guide members 25 that guide primary light, and a light source 21. And a demultiplexing unit 27 that demultiplexes the primary light emitted from the light into a plurality of primary lights. The illumination unit 20 converts the optical characteristics of the primary light guided by the light guide member 25, and illuminates the subject 13 with the primary light having the converted optical characteristics as illumination light IL, and It has the same number of the illumination units 29 and is arranged in pairs with the illumination units 29, and has an optical element 31 through which the illumination light IL emitted from the illumination unit 29 is transmitted.

[Light source 21]
The light source 21 includes, for example, a laser diode that emits blue laser light. The center wavelength of the laser light is, for example, 445 nm. The light source 21 may emit light of other colors. The light source 21 may be provided inside a housing part provided outside the endoscope, or may be provided inside the endoscope.

[Light source control unit 23]
The light source control unit 23 supplies power necessary for the light source 21 to drive to the light source 21. The light source control unit 23 supplies power to the light source 21 that is equal to or greater than a predetermined threshold power and is proportional to the amount of illumination light IL, or supplies power to the light source 21 according to the driving interval of the light source 21. The light source control unit 23 supplies power when a first operation unit (not shown) is operated. The first operation unit is operated to instruct the operator to turn on or off the emission of the illumination light IL. When the light source 21 is provided inside the housing unit, the light source control unit 23 and the first operation unit are provided inside the housing unit. When the light source 21 is provided inside the endoscope, the light source control unit 23 is provided inside the endoscope. The first operation unit is provided in the endoscope.

[Light guide member 25]
As shown in FIG. 1A, the light guide member 25 is provided between the light source 21 and the demultiplexing unit 27 and guides the primary light emitted from the light source 21 to the demultiplexing unit 27. The light guide member 25 is further provided between the demultiplexing unit 27 and the illumination unit 29, and guides the primary light demultiplexed by the demultiplexing unit 27 to the illumination unit 29. Such a light guide member 25 includes, for example, an optical fiber. The core diameter of the optical fiber is, for example, 50 μm and the numerical aperture FNA = 0.2, and the optical fiber is a multimode optical fiber. When the light source 21 is provided inside the casing, the light guide member 25 is provided inside the casing and inside the endoscope. When the light source 21 is provided inside the endoscope, the light guide member 25 is provided inside the endoscope.

[Demultiplexer 27]
As illustrated in FIG. 1A, the demultiplexing unit 27 demultiplexes the primary light in accordance with the number of illumination units 29. In the present embodiment, for example, since two illumination units 29 are provided, the demultiplexing unit 27 demultiplexes the primary light into two. The demultiplexing unit 27 demultiplexes the primary light at a desired ratio, for example. In the present embodiment, the ratio is, for example, 50:50. The ratio need not be uniform.
When only one illumination unit 29 is provided, the demultiplexing unit 27 is omitted, and the light source 21 is connected to the illumination unit 29 via the light guide member 25.

Although not shown, the demultiplexing unit 27 is optically connected to the light guide member 25 by an optical connector (not shown). For example, when the light source 21 is provided inside the housing unit, the demultiplexing unit 27 may be provided inside the housing unit or may be provided inside the endoscope. For example, when the light source 21 is provided inside the endoscope, the demultiplexing unit 27 is provided inside the endoscope.

[Lighting unit 29]
As shown in FIG. 1A, the illumination unit 29 is fixed to the inside of the distal end portion 11 of the insertion portion by, for example, an adhesive. When the illumination unit 29 receives the primary light guided by the light guide member 25, the illumination unit 29 functions as a light conversion unit that converts the optical characteristics of the primary light to a desired value. For example, the illumination unit 29 generates illumination light IL having a light distribution characteristic different from the primary light, and emits the illumination light IL. Thus, the illumination unit 29 functions as a light distribution conversion unit that converts the light distribution of the primary light. The light distribution characteristic of the illumination light IL has a property that does not vary depending on the amount of primary light.

As shown in FIG. 1B, the illumination unit 29 is interposed between the light conversion member 29a and the light emitting member 29a and the light conversion member 29a in the traveling direction of the primary light, and the traveling direction of the primary light. The light transmission member 29b is optically connected to the light output end face of the light guide member 25 and the light conversion member 29a. The illumination unit 29 holds the reflection member 29c provided on the side of the light conversion member 29a and the transmission member 29b, the tip of the light guide member 25, the light conversion member 29a, the transmission member 29b, and the reflection member 29c. And a member 29d.

[Light conversion member 29a]
As shown in FIG. 1B, the light conversion member 29a is provided in front of the transmission member 29b in the traveling direction of the primary light, and is optically connected to the transmission member 29b. The light conversion member 29a has a truncated cone shape. The truncated cone expands in diameter according to the traveling direction of the primary light. The shape of the base end surface of the light conversion member 29a is substantially the same as the shape of the front end surface of the transmission member 29b, and the base end surface of the light conversion member 29a is in direct contact with the front end surface of the transmission member 29b. The shape in which the light conversion member 29a and the transmission member 29b are combined is a truncated cone shape. The truncated cone expands in diameter according to the traveling direction of the primary light.

The light conversion member 29a emits primary light incident on the light conversion member 29a as illumination light IL toward the front on the subject 13 side and the rear on the light guide member 25 side.

The light conversion member 29a includes at least one of a phosphor (not shown) and a diffusion member (not shown), and a sealing member (not shown) that seals at least one of the phosphor and the diffusion member.

The phosphor is a wavelength conversion member that absorbs the primary light and converts the primary light into converted light having a wavelength longer than that of the primary light. The phosphor is, for example, a powder represented by YAG: Ce. The phosphor has a function of absorbing the primary light in the blue wavelength region and converting the wavelength of the primary light into yellow fluorescence that is the illumination light IL. Further, since yellow fluorescence is emitted without directivity, the phosphor also has a diffusion function. The sealing member collectively includes the phosphors in a state where the powdery phosphors are dispersed in the sealing member.

The diffusing member has a function of converting the primary light incident on the diffusing member into diffused light with a reduced coherence by expanding the light distribution angle of the primary light without changing the wavelength of the primary light. The diffusing member emits diffused light as illumination light IL. The diffusion member is a fine particle formed of a metal or a metal compound. Such a diffusing member is, for example, alumina or titanium oxide. The sealing member collectively includes the diffusion member in a state where the diffusion members are dispersed in the sealing member.

The sealing member is formed of a member that transmits the primary light and the illumination light IL. Such a sealing member is, for example, a transparent silicone resin or a transparent epoxy resin. The sealing member has a high transmittance with respect to the primary light and the illumination light IL.

The refractive index of the diffusion member is different from the refractive index of the sealing member. For example, the refractive index of the diffusing member is higher than the refractive index of the sealing member, and is preferably 1.5 or more. Thereby, the diffusion member can improve the diffusibility of the primary light. The light distribution angle of the light conversion member 29a is controlled by, for example, the concentration of the diffusion member with respect to the sealing member, the thickness of the light conversion member 29a, and the like. For example, when the refractive index of the diffusing member is 1.7 and the refractive index of the sealing member is 1.4, the volume concentration of the diffusing member with respect to the sealing member is 20%, and the thickness of the light conversion member 29a is 0.1 mm. It becomes. Thereby, the primary light is sufficiently diffused as diffused light (illumination light IL), and the light distribution angle of the illumination light IL is sufficiently widened.

[Transparent member 29b]
The transmitting member 29b has a property of transmitting the primary light and the illumination light IL. The transmissive member 29b is formed of glass having a high transmittance or a silicone resin having a high transmittance. The transmission member 29b has a truncated cone shape. The truncated cone expands in diameter according to the traveling direction of the primary light.

[Reflection member 29c]
The reflection member 29c regularly reflects or diffusely reflects the primary light and the incident light incident on the reflection member 29c. The reflection member 29c may be scattered and reflected. The incident light is illumination light IL emitted backward from the light conversion member 29a. The reflecting member 29c is a thin film of metal such as silver or aluminum.

[Holding member 29d]
As shown in FIG. 1B, the holding member 29d has a first hole 29e with which the light guide member 25 is engaged, and a second hole 29f with which the light conversion member 29a and the transmission member 29b are engaged. The first hole 29e is provided coaxially with the second hole 29f, and communicates with the second hole 29f. For example, the first hole 29e has a cylindrical shape. For example, the second hole 29f has a truncated cone shape. The truncated cone expands in diameter according to the traveling direction of the primary light. A reflective member 29c is provided on the inner peripheral surface of the second hole 29f.

When the light guide member 25 is engaged with the first hole 29e and the light conversion member 29a and the transmission member 29b are engaged with the second hole 29f, the holding member 29d is connected to the light guide member 25 and the light conversion member 29a. The transmission member 29b is held. Thereby, the light guide member 25 is optically connected to the transmission member 29b, the transmission member 29b is optically connected to the light conversion member 29a, and the reflection member 29c is connected to the side surface of the light conversion member 29a and the side surface of the transmission member 29b. To be optically connected. When the holding member 29d holds the light conversion member 29a, the tip surface of the light conversion member 29a is provided on the same plane as the tip surface of the holding member 29d.

The taper angle of the second hole 29f, the light conversion member 29a, and the transmission member 29b is set to, for example, approximately 10 degrees to approximately 60 degrees with respect to the longitudinal axis of the holding member 29d. In the present embodiment, for example, the taper angle is 25 degrees. Accordingly, the illumination light IL that is non-directional fluorescence and the illumination light IL that is diffused diffused light are efficiently emitted from the illumination unit 29.

[Optical element 31]
As shown in FIGS. 1A and 1B, one optical element 31 is arranged with respect to one illumination unit 29, and the optical element 31 is arranged in front of the illumination unit 29. The optical element 31 is a lens through which the illumination light IL emitted from the illumination unit 29 is transmitted. Each optical element 31 is held by an adjustment mechanism 70 described later in the distal end portion 11 of the insertion portion. Each optical element 31 can be simultaneously moved in the axial direction of the optical element 31 by the adjusting mechanism 70, and approaches or moves away from the illumination unit 29 by the movement. That is, the relative distance between the optical element 31 and the illumination unit 29 can be adjusted by the adjustment mechanism 70.

[Imaging unit 40]
As illustrated in FIG. 1A, the imaging unit 40 generates a captured image 301 by performing image processing on the reflected light RL captured by the imaging unit 41 and an imaging unit 41 that captures the reflected light RL reflected from the subject 13. And an image processing unit (not shown). The imaging unit 40 starts an imaging operation when a second operation unit (not shown) is operated. The second operation unit is disposed in the operation unit of the endoscope.

The imaging unit 41 includes, for example, a CCD or a CMOS. The imaging unit 41 has a color filter for each pixel, and has a color pixel group. As shown in FIGS. 1A and 1B, an optical element 43 that transmits the reflected light RL is provided in front of the imaging unit 41. The reflected light RL passes through the optical element 43 and enters the imaging unit 42. The optical element 43 has substantially the same configuration as the optical element 31. Unlike the optical element 31, the optical element 43 is fixed inside the distal end portion 11 of the insertion portion.

As shown in FIG. 1A, FIG. 1B, and FIG. 1C, the imaging unit 41 is provided between the two illumination units 29 and is fixed inside the distal end portion 11 of the insertion unit. In other words, the illumination units 29 are provided symmetrically with respect to each other about the imaging unit 41. The illumination units 29 may be provided asymmetrically so that the observation is optimally performed.

The image processing unit may be provided inside a casing unit provided outside the endoscope, or may be provided inside the endoscope.

[Representative value extraction unit]
As shown in FIG. 1A, the endoscope system 10 extracts a representative value that extracts a representative value indicating a state of a pixel value of a captured image 301 (see FIGS. 2A, 2B, 2C, and 2D) captured by the imaging unit 40. (Hereinafter referred to as the extraction unit 61). In the present embodiment, the extraction unit 61 extracts a contrast value that is an example of a representative value. For example, the extraction unit 61 starts extraction after the imaging unit 40 starts an imaging operation.

The extraction unit 61 receives a captured image 301 including pixel value information of blue pixels, green pixels, and red pixels from the imaging unit 40. The extraction unit 61 divides the captured image 301 into a plurality of regions. The extraction unit 61 extracts a high-frequency component of the pixel for each divided area using a bandpass filter. The extraction unit 61 integrates the extracted high frequency components and extracts a contrast value for each region. As described above, the extraction unit 61 divides the captured image 301 into a plurality of regions, and extracts a contrast value for each of the divided regions.

For example, the extraction unit 61 may extract a contrast value based on any one of the color pixel values.
For example, the extraction unit 61 extracts a contrast value based on a value obtained by adding the color pixel values.
For example, the extraction unit 61 may extract a contrast value based on the luminance value.
The luminance value is calculated based on, for example, the following formula (1).
Luminance value = 0.299 × red pixel value + 0.587 × green pixel value + 0.114 × blue pixel value Equation (1).

[Attention area determination unit]
As shown in FIG. 1A, the endoscope system 10 includes a region of interest 201 (FIGS. 2A, 2B, 2C, and 2C) that is a region of interest for observation based on the captured image 301 of the subject 13 captured by the imaging unit 40. It further includes an attention area determination unit (hereinafter referred to as a determination unit 63) that determines (see 2D).

The determining unit 63 calculates whether or not the contrast value extracted by the extracting unit 61 is higher than a predetermined value. The determination unit 63 determines an area having a contrast value calculated to be higher than the predetermined value as the attention area 201. For example, when the subject 13 is a tumor, the convex and concave portions present on the surface of the portion where blood vessels are present in the tumor are present more finely than the portion where the tumor is not present. The contrast value is large at the portion where the convex / concave portion exists, and the contrast value is small at the portion where the convex / concave portion does not exist. The predetermined value is set based on the maximum contrast value on the captured image 301. Thereby, the determination part 63 can determine the attention area | region 201 stably. The predetermined value may be set by integrating a value of a predetermined ratio with respect to the maximum value. The value of the predetermined ratio may be set according to the subject 13. As described above, since the contrast value is large in the portion where the convex / concave portion exists, at least a part of this portion is determined as the attention area 201.

The determining unit 63 may determine the logical sum of the attention areas 201 corresponding to the respective color pixels as the final attention area 201.

When the part with a high contrast value is separated into a plurality of discontinuous areas, the determination unit 63 may determine one area including all the parts with a high contrast value as the attention area 201. The determination unit 63 may determine the attention area 201 so that the attention area 201 includes all the portions having high contrast values and the attention area 201 is set to the minimum area.

The determination unit 63 may determine the attention area 201 such that the end of the captured image 301 is excluded from the attention area 201. When both ends are dark, the determination unit 63 may perform a process in which the contrast value indicates the original value.

[Lighting area identification part]
As illustrated in FIG. 1A, the endoscope system 10 is configured to identify an illumination area 203 (see FIGS. 2A, 2B, 2C, and 2D) that is an area illuminated by the illumination light IL based on the captured image 301. An area specifying unit (hereinafter referred to as specifying unit 65) is further included.

The identifying unit 65 identifies an area having a brightness equal to or higher than a predetermined brightness in the captured image 301 as the illumination area 203. The specifying unit 65 calculates the brightest pixel value (hereinafter, the brightest pixel value) in the captured image 301. The specifying unit 65 calculates a pixel value (hereinafter, referred to as a predetermined pixel value) having a predetermined percentage of the brightness of the brightest pixel value from the captured image 301. The specifying unit 65 specifies an area having a predetermined pixel value as the illumination area 203. The illumination area 203 is an area having a luminance value equal to or higher than a predetermined luminance value corresponding to the brightness necessary for observation in the captured image 301. The specifying unit 65 may specify the illumination area 203 for each illumination unit 29, for example. In the following, as shown in FIG. 2A, the illumination region 203 corresponding to one illumination unit 29 is referred to as illumination region 203a, the illumination region 203 corresponding to the other illumination unit 29 is referred to as illumination region 203b, and illumination regions 203a, 203b is collectively referred to as an illumination area 203.

The identifying unit 65 may identify an area having brightness such that the imaging unit 40 can output signal characteristics desirable for the imaging unit 40 as the illumination area 203.

[Scheduled illumination area setting section]
As shown in FIG. 1A, the endoscope system 10 is based on a region of interest 201 and an illumination region 203, and is a planned illumination region 205 (FIGS. 2A, 2B, 2C, 2D) further includes a scheduled illumination area setting unit (hereinafter referred to as a setting unit 67).

As shown in FIG. 2A, in a state where the attention area 201 is larger than the illumination area 203 and the attention area 201 includes the illumination area 203, the illumination scheduled area 205 is, for example, inside the attention area 201 and the illumination area 203. Is an external area. The planned illumination area 205 is an area that needs to be illuminated but is not actually illuminated. In this case, the planned illumination area 205 is a logical difference between the attention area 201 and the illumination area 203. Therefore, the setting unit 67 sets an area calculated by subtracting the illumination area 203 from the attention area 201 as the scheduled illumination area 205.
As illustrated in FIG. 2C, the illumination planned area 205 is the attention area 201 in a state where the illumination area 203 is larger than the attention area 201 and the illumination area 203 includes the attention area 201. Therefore, the setting unit 67 sets the attention area 201 as the scheduled illumination area 205.
The processing in the extraction unit 61, the determination unit 63, the specifying unit 65, and the setting unit 67 may be executed by a processor including a hardware configuration. For example, the processing may be executed by a processor including an electronic circuit such as an ASIC (Application Specific Integrated Circuit). Alternatively, the processing may be executed by a general-purpose processor such as a CPU (Central Processing Unit) reading various programs.

[Adjustment mechanism 70 and control unit 80]
As shown in FIG. 1A, the endoscope system 10 includes an adjustment mechanism 70 that adjusts the optical characteristics of the illumination light IL so that the planned illumination area 205 is illuminated with the illumination light IL, a light source control unit 23, and an adjustment mechanism. And a control unit 80 for controlling the entire endoscope system 10 including the control unit 70. The control of the control unit 80 with respect to the adjustment mechanism 70 and the operation of the adjustment mechanism 70 include a state in which the first operation unit is operated, the illumination unit 29 is driven, and the illumination light IL is emitted, and the second operation unit is operated. In the state where the imaging unit 40 is driven.

The adjusting mechanism 70 adjusts the optical characteristics of the illumination light IL so that the area of the illumination scheduled area 205 satisfies a predetermined standard.
As shown in FIG. 2A, for example, in a state where the attention area 201 is larger than the illumination area 203 and the attention area 201 includes the illumination area 203, the control unit 80 calculates and calculates the area of the scheduled illumination area 205. Based on the result, the adjusting mechanism 70 adjusts the light distribution.
In this case, for example, the control unit 80 controls the optical characteristics of the illumination light IL via the adjustment mechanism 70 so that the area of the planned illumination area 205 illustrated in FIG. 2A is equal to or less than a predetermined ratio of the area of the attention area 201. . The predetermined ratio is, for example, 10%, and is a ratio at which it can be determined that the illumination scheduled area 205 has been substantially eliminated as shown in FIG. 2B. Substantially elimination of the scheduled illumination area 205 indicates that the area not illuminated with the illumination light IL is substantially eliminated. By setting the predetermined ratio to be high, the illumination light IL is illuminated up to the entire region of interest 201.
As shown in FIG. 2B, in order to eliminate the planned illumination area 205, the control unit 80 controls the adjustment mechanism 70, and the adjustment mechanism 70 adjusts the light distribution in the optical characteristics of the illumination light IL by the control. By this adjustment, the illumination area 203 is enlarged so as to approximate the attention area 201. When the illumination area 203 is enlarged and the area of the scheduled illumination area 205 becomes 10% or less of the area of the attention area 201, the control unit 80 stops the light distribution adjustment of the adjustment mechanism 70. The control unit 80 may perform hill climbing control using the area as an evaluation value so that the area of the planned illumination area 205 is minimized.

As shown in FIG. 2C, for example, in a state where the illumination area 203 is larger than the attention area 201 and the illumination area 203 includes the attention area 201, the control unit 80 sets the attention area 201, which is the scheduled illumination area 205. The area is calculated, and the adjustment mechanism 70 adjusts the light distribution based on the calculation result.
In this case, the control unit 80 causes the illumination light IL to pass through the adjustment mechanism 70 so that the area of the region 207 (see FIG. 2C) between the attention region 201 and the illumination region 203 is equal to or less than a predetermined ratio of the area of the attention region 201. Control the optical properties of The predetermined ratio is, for example, 10%, and is a ratio at which it can be determined that the area 207 is almost eliminated as shown in FIG. 2D. The almost elimination of the area 207 indicates that the unnecessary illumination light IL is almost eliminated. By setting the predetermined ratio to be high, the illumination light IL is focused on the entire attention area 201 and illuminated.
In order to eliminate the region 207 as shown in FIG. 2D, the control unit 80 controls the adjustment mechanism 70, and the adjustment mechanism 70 adjusts the light distribution in the optical characteristics of the illumination light IL by the control. By this adjustment, the illumination area 203 is reduced so as to approximate the attention area 201. When the illumination area 203 is reduced and the area of the area 207 becomes 10% or less of the area of the attention area 201, the control unit 80 stops the light distribution adjustment of the adjustment mechanism 70.

As shown in FIG. 1B, the adjustment mechanism 70 includes a drive source 71 controlled by the control unit 80, a transmission unit 73 that transmits the driving force output from the drive source 71, and a driving force that is transmitted from the transmission unit 73. The adjusting member 75 for adjusting the relative distance between the illumination unit 29 and the optical element 31 is provided.
The drive source 71 has a micromotor.
The transmission part 73 has a ball screw. The ball screw is screwed into the adjustment member 75.

The adjusting member 75 holds the optical element 31 so that the optical element 31 is arranged corresponding to the illumination unit 29. Specifically, the adjustment member 75 holds the optical element 31 so that the optical element 31 is disposed in front of the illumination unit 29. One adjusting member 75 holds all the optical elements 31. The adjustment member 75 has an imaging hole 75a provided in front of the optical element 43 so that the imaging of the imaging unit 41 is not blocked.

When the ball screw rotates around the axis of the ball screw by the driving force, the adjustment member 75 moves along the axial direction of the optical element 31 by the rotation of the ball screw. The optical element 31 held by the adjustment member 75 moves along the axial direction of the optical element 31 with respect to the illumination unit 29 in conjunction with the adjustment member 75. Thereby, the relative distance between the illumination part 29 and the optical element 31 is adjusted, and the light distribution which is the optical characteristic of the illumination light IL is adjusted by adjusting the relative distance. Then, the illumination area 203 is enlarged or reduced so as to approximate the attention area 201, the illumination scheduled area 205 is canceled along with the enlargement, and the area 207 is eliminated along with the reduction. As a result, the illumination scheduled area 205 illuminates the illumination light IL. Is done. The axial direction of the optical element 31 coincides with the longitudinal axis direction of the insertion portion and coincides with the optical axis direction of the primary light. The optical axis of the primary light indicates the central axis of the primary light emitted from the distal end surface of the light guide member 25 connected to the transmission member 29b.

1B, the illumination unit 29 is fixed, the adjustment member 75 holds the optical element 31, and the adjustment member 75 moves, so that the optical element 31 moves. The relative distance is adjusted, but the adjustment of the relative distance need not be limited to this.
For example, the optical element 31 may be fixed, the adjustment member 75 may hold the illumination unit 29, and the adjustment unit 75 may move to move the illumination unit 29 relative to the optical element 31. Thereby, the relative distance may be adjusted.
Alternatively, the adjustment member 75 may hold at least one of the illumination unit 29 and the optical element 31, and when the adjustment member 75 moves, at least one of the illumination unit 29 and the optical element 31 may move relative to the other. . Thereby, the relative distance may be adjusted.
As described above, the adjustment mechanism 70 adjusts the optical distance of the illumination light IL by adjusting the relative distance between the illumination unit 29 and the optical element 31. The relative distance is adjusted stepwise or continuously. The adjustment mechanism 70 adjusts the optical characteristics of the illumination light IL in a state where the illumination unit 20 is illuminating and the imaging unit 40 is imaging. In the present embodiment, one adjustment mechanism 70 adjusts the optical characteristics of the illumination light IL emitted from all the illumination units 20 simultaneously in conjunction with all the illumination units 29.

[Action]
[Lighting operation and imaging operation]
When the first operation unit is operated to instruct to turn on the emission of the illumination light IL, the light source control unit 23 controls the light source 21 to emit the primary light. The primary light emitted from the light source 21 passes through the light guide member 25, the demultiplexing unit 27, and the light guide member 25 and proceeds to the illumination unit 29. In the illumination unit 29, the primary light passes through the transmission member 29b and irradiates the light conversion member 29a.

When the light conversion member 29a includes a phosphor, a diffusion member, and a sealing member, a part of the primary light is absorbed by the phosphor and converted into light having a wavelength longer than the wavelength of the primary light. This light is referred to as converted light. The remaining part of the primary light is diffused by the diffusing particles. This light is called diffuse light. It is preferable that the light distribution characteristic of the converted light and the light distribution characteristic of the diffused light are substantially equal to each other.

As shown in FIG. 1A, the converted light and the diffused light are incident on the optical element 31 as illumination light IL. The light distribution of the illumination light IL is adjusted by the principle of adjusting the light distribution described later in the optical element 31. In the adjusted state, the illumination light IL is emitted outward from the optical element 31 to illuminate the subject 13.

When the second operation unit is operated to instruct the start of the imaging operation, the imaging unit 40 is driven. As shown in FIG. 1A, the illumination light IL is reflected and diffused by the subject 13, and the reflected light RL enters the imaging unit 41. The imaging unit 41 captures the reflected light RL, the image processing unit generates a captured image 301 based on the reflected light RL, and the display unit 50 displays the captured image 301.

[Principle for adjusting light distribution, which is an optical property]
This adjustment is performed based on the relative distance between the illumination unit 29 and the optical element 31 and the focal length of the optical element 31. It is assumed that the illumination light IL emitted from the illumination unit 29 is emitted from a point light source that exists at the center of the emission opening of the illumination unit 29.

As shown in FIGS. 3A and 3B, the distance from the center of the optical element 31 to the focal point of the optical element 31 is defined as a focal length F of the optical element 31.
A distance from the center of the optical element 31 to the emission end face of the illumination unit 29 is a distance L1.
A distance from the center of the optical element 31 to the reference position of the light distribution angle of the illumination light IL is defined as a distance L2. In this case, the reference position of the light distribution angle is located on the light guide member 25 side with respect to the position of the optical element 31.

In the case of L1 <F, the distance L2 is calculated by the following formula (2) in the focal length F, the distance L1, and the distance L2.
1 / L1 + 1 / L2 = 1 / F Equation (2)
The illumination light IL spreads through the optical element 31 starting from the reference position of the light distribution angle calculated by the distance L2.

When the distance L1 is shorter than the focal length F as described above, when the ball screw is rotated in the first direction around the axis of the ball screw by the driving force in the adjustment mechanism 70, the adjustment member 75 is along the axial direction of the optical element 31. To move away from the illumination unit 29. The optical element 31 held by the adjustment member 75 moves along the axial direction of the optical element 31 with respect to the illumination unit 29 in conjunction with the adjustment member 75, and moves away from the illumination unit 29. Thereby, the distance L1, which is the relative distance between the illumination unit 29 and the optical element 31, is adjusted to be long, and the distance L2 is shortened. Therefore, the light distribution angle of the illumination light IL is widened, and the illumination area 203 is enlarged as shown in FIG. 2B. Then, the illumination area 203 is enlarged so as to approximate the attention area 201, and the illumination planned area 205 is canceled along with the enlargement. As a result, the illumination scheduled area 205 is illuminated with the illumination light IL.

When the distance L1 is longer than the focal length F, the adjusting member 75 rotates the optical element in the second direction opposite to the first direction around the axis of the ball screw by the driving force in the adjusting mechanism 70. It moves in the direction approaching the illumination unit 29 along the axial direction of 31. The optical element 31 held by the adjustment member 75 moves along the axial direction of the optical element 31 with respect to the illumination unit 29 in conjunction with the adjustment member 75, and approaches the illumination unit 29. Thereby, the distance L1, which is the relative distance between the illumination unit 29 and the optical element 31, is adjusted to be short, and the distance L2 is lengthened. Therefore, the light distribution angle of the illumination light IL is narrowed, and the illumination area 203 is reduced and the area 207 is narrowed as shown in FIG. 2D. Then, the illumination area 203 is reduced so as to approximate the attention area 201, and unnecessary illumination light IL is eliminated along with the reduction. As a result, the attention area 201 that is the planned illumination area 205 is illuminated with the illumination light IL.

[Adjustment of light distribution as optical characteristics]
The light distribution adjustment will be described with reference to FIG.
The illumination unit 29 is driven according to the operation of the first operation unit, and the illumination unit 29 emits illumination light IL and illuminates the subject 13 with the illumination light IL (Step 1).
In a state where the illumination light IL is emitted, the imaging unit 40 images the subject 13 illuminated with the illumination light IL in accordance with the operation of the second operation unit (Step 2).

The identifying unit 65 identifies the illumination area 203 from the captured image 301 captured by the imaging unit 40 (Step 3).

The extraction unit 61 extracts the contrast value and outputs the contrast value to the determination unit 63 (Step 4).

The determining unit 63 determines the attention area 201 based on the contrast value extracted by the extracting unit 61 (Step 5).

The setting unit 67 sets the scheduled illumination area 205 based on the attention area 201 and the illumination area 203 (Step 6). In Step 6, the setting unit 67 outputs information related to the planned illumination area 205 to the control unit 80.

The control unit 80 controls the adjustment mechanism 70 based on this information. And the adjustment mechanism 70 adjusts the relative distance between the optical element 31 and the illumination part 29 based on control of the control part 80 (Step7). Thereby, the illumination planned area 205 is illuminated with the illumination light IL (Step 8).

In Steps 5 and 6, as shown in FIG. 2A, for example, in a state where the attention area 201 is larger than the illumination area 203 and the attention area 201 includes the illumination area 203, the illumination scheduled area 205 is, for example, This is an area inside 201 and outside the illumination area 203. And it is necessary to expand so that the illumination area | region 203 may approximate the attention area 201. FIG. For this reason, as described above, in Step 7, the optical element 31 is adjusted so that the distance L1 as the relative distance is long and the distance L2 is short, away from the illumination unit 29. Thereby, the light distribution angle of the illumination light IL is widened, and as shown in FIG. 2B, the illumination area 203 is enlarged so as to approximate the attention area 201, and the planned illumination area 205 is eliminated along with the enlargement. As a result, in Step 8, the illumination planned area 205 is illuminated with the illumination light IL. When the illumination area 203 is enlarged and the area of the illumination scheduled area 205 becomes 10% or less of the area of the attention area 201, the control unit 80 stops the adjustment.

In Steps 5 and 6, as shown in FIG. 2C, for example, when the illumination area 203 is larger than the attention area 201 and the illumination area 203 includes the attention area 201, the planned illumination area 205 is the attention area 201. . Then, it is necessary to reduce the illumination area 203 so as to approximate the attention area 201. For this reason, as described above, in Step 7, the optical element 31 is adjusted so as to approach the illuminating unit 29, the relative distance L1 is short, and the distance L2 is long. Thereby, the light distribution angle of the illumination light IL is narrowed, and as shown in FIG. 2D, the illumination area 203 is reduced and the area 207 is narrowed. Then, the illumination area 203 is reduced to approximate the attention area 201, and unnecessary illumination light IL is eliminated along with the reduction. As a result, in Step 8, the attention area 201 which is the illumination scheduled area 205 is illuminated with the illumination light IL. When the area of the area 207 becomes 10% or less of the area of the attention area 201, the adjustment mechanism 70 stops the adjustment.

After step 8, the light distribution adjustment is completed. When the endoscope system 10 observes another subject 13, the operations of Step 1 to Step 8 are repeated in this order. Note that the operations of Step 2 to Step 8 may be repeatedly performed in this order at the time of observation.

[effect]
In this embodiment, the illumination area 203 is enlarged to the attention area 201 as shown in FIGS. 2A and 2B, or the illumination area 203 is reduced to the attention area 201 as shown in FIGS. 2C and 2D. Thereby, in this embodiment, the illumination light IL can be sufficiently distributed without being influenced by the viewing angle, and the waste of the illumination light IL can be suppressed.

In this embodiment, the attention area 201 is determined based on the contrast value. For example, when the subject 13 is a tumor, the contrast value becomes large at the site where the convex and concave portions exist on the surface of the site where the blood vessel exists in the tumor. For this reason, it is possible to illuminate the illumination light IL reliably and without waste to the convex and concave portions.

[Modification]
In the first embodiment, the determination unit 63 determines the attention area 201 based on the contrast value extracted by the extraction unit 61. However, the determination of the attention area 201 need not be limited to this.

As shown in FIGS. 1A and 5, the determination unit 63 determines the attention region 201 based on the region specified by the specification unit 120 from the image displayed on the display unit 50. In this case, the designation unit 120 is an input unit that is input to the endoscope system 10 by the operator. The designation unit 120 is, for example, a mouse or a keyboard. The designation unit 120 designates a region of particular interest of the subject 13 from the image displayed on the display unit 50. When the designation unit 120 is a mouse, the designation unit 120 designates, from the image displayed on the display unit 50, the start point and the end point diagonal to the start point at the tip of the mouse arrow. The designation unit 120 designates an area formed by the start point and the end point. The determination unit 63 determines the designated area as the attention area 201. Alternatively, the designation unit 120 designates a start point at the tip of the mouse arrow, and designates an area having an arbitrary radius with the start point as a center point. The determination unit 63 determines the designated area as the attention area 201. When the designation unit 120 is a keyboard, the designation unit 120 designates a rectangular region or an XY coordinate of the center point by designating the XY coordinates of the diagonal points of the rectangle from the image displayed on the display unit 50. Specify a circular area. The determination unit 63 determines this area as the attention area 201.

In the present modification, after Steps 1, 2, and 3 are sequentially performed, the designation unit 120 designates an area from the image displayed on the display unit 50 (Step 11). Next, the determination unit 63 determines the region specified by the specifying unit 120 as the attention region 201 (Step 12). Next, Steps 6, 7, and 8 are sequentially performed.

In this modification, the attention area 201 can be manually designated by the designation unit 120.

[Second Embodiment]
Hereinafter, only points different from the first embodiment will be described with reference to FIGS. 6A, 6B, 6C, 6D, and 6E. One or more illumination units 29 may be arranged. In the first embodiment, the light emitted from the illumination unit 29 is defined as the illumination light IL. However, in this embodiment, the light emitted from the illumination unit 29 is the secondary light SL (FIGS. 6B and 6C). And the light emitted from the light distribution adjustment illumination unit 90 is defined as illumination light IL (see FIGS. 6B and 6C).

[Constitution]
[Light distribution adjustment lighting unit 90]
As illustrated in FIG. 6A, the illumination unit 20 receives the secondary light SL emitted from the illumination unit 29, adjusts the light distribution characteristics of the received secondary light SL, and has the adjusted light distribution characteristics. It further includes a light distribution adjusting illumination unit 90 that emits the light IL to the outside. The light distribution characteristic of the secondary light SL emitted from the illumination unit 29 is fixed. The light distribution adjusting illumination units 90 are arranged in the same number as the illumination units 29 and in pairs with the illumination units 29.

As shown in FIGS. 6B and 6C, the light distribution adjustment illumination unit 90 can be moved along the optical axis direction of the primary light with respect to the illumination unit 29 by the adjustment mechanism 70. The optical axis of the primary light indicates the central axis of the primary light emitted from the distal end surface of the light guide member 25 connected to the transmission member 29b. The light distribution adjustment lighting unit 90 varies the adjustment amount of the light distribution characteristic according to the movement amount.

As shown in FIG. 6A, the light distribution adjustment illumination unit 90 includes a hollow member 91 in which the illumination unit 29 is disposed, an optical element 93 provided in the hollow member 91, and a reflection member 95 provided in the hollow member 91. Have

[Hollow member 91]
As shown in FIG. 6A, the hollow member 91 has a first hole 91a and a second hole 91b. The first hole portion 91a is provided coaxially with the second hole portion 91b and communicates with the second hole portion 91b. For example, the first hole portion 91a has a cylindrical shape. For example, the second hole portion 91b has a truncated cone shape. The truncated cone expands in diameter according to the traveling direction of the primary light. The illumination unit 29 is inserted into the first hole 91a and the second hole 91b. The first hole 91 a and the second hole 91 b are larger than the illumination unit 29. The hollow member 91 is connected to the adjustment member 75.

[Optical element 93]
As shown in FIG. 6A, the optical element 93 is a transmissive member through which the secondary light SL having the light distribution characteristic adjusted by the light distribution adjusting illumination unit 90 is transmitted. The optical element 93 is made of, for example, glass having a high transmittance. The optical element 93 has a cylindrical shape, for example. The optical element 93 is fixed to the distal end surface of the hollow member 91 by adhesion so that the optical element 93 is disposed in front of the illumination unit 29, and covers the second hole 91b.

[Reflection member 95]
As shown in FIG. 6A, the reflecting member 95 is provided on the inner peripheral surface of the second hole portion 91b. The reflection member 95 regularly reflects or diffusely reflects incident light incident on the reflection member 95. The reflection member 95 may be scattered and reflected. The incident light is secondary light SL including fluorescence and diffused light. The reflecting member 95 is a metal thin film such as silver or aluminum. The reflection member 95 is plated on the inner peripheral surface.

[Adjustment mechanism 70]
As shown in FIG. 6A, in the adjustment mechanism 70, the adjustment member 75 directly holds the light distribution adjustment illumination unit 90 and holds the optical element 93 via the hollow member 91.

As shown in FIG. 6A, the adjustment member 75 includes an illumination unit 29 inserted into the first hole 91a and the second hole 91b, an optical element 93 disposed in front of the illumination unit 29, and a light distribution adjustment illumination unit 90. Is held on the same axis as the optical axis of the primary light.

As shown in FIGS. 6B and 6C, when the ball screw is rotated around the axis of the ball screw by the driving force, the adjustment member 75 moves along the optical axis direction of the primary light by the rotation of the ball screw. The light distribution adjustment illumination unit 90 held by the adjustment member 75 moves along the optical axis direction of the primary light with respect to the illumination unit 29 in conjunction with the adjustment member 75. Thereby, the relative distance between the illumination unit 29 and the optical element 93 is adjusted, and the optical characteristic of the illumination light IL is adjusted by adjusting the relative distance. Then, the illumination area 203 is enlarged or reduced so as to approximate the attention area 201, and the illumination scheduled area 205 is canceled along with the enlargement, or the area 207 is eliminated along with the reduction, and as a result, the illumination scheduled area 205 receives the illumination light IL. Illuminated.

The illumination unit 29 is fixed, the adjustment member 75 holds the light distribution adjustment illumination unit 90, and the adjustment member 75 moves, so that the light distribution adjustment illumination unit 90 moves. The relative distance is adjusted, but the adjustment of the relative distance need not be limited to this.
For example, the light distribution adjustment illumination unit 90 may be fixed, the adjustment member 75 may hold the illumination unit 29, and the adjustment member 75 may move to move the illumination unit 29 relative to the light distribution adjustment illumination unit 90. . Thereby, the relative distance may be adjusted.
Alternatively, the adjustment member 75 holds at least one of the illumination unit 29 and the light distribution adjustment illumination unit 90, and when the adjustment member 75 moves, at least one of the illumination unit 29 and the light distribution adjustment illumination unit 90 is opposed to the other. You may move. Thereby, the relative distance may be adjusted.
As described above, the adjustment mechanism 70 adjusts the optical characteristic of the illumination light IL by adjusting the relative distance between the illumination unit 29 and the light distribution adjustment illumination unit 90. The relative distance is adjusted stepwise or continuously.

[Extractor 61]
In the present embodiment, the extraction unit 61 divides the captured image 301 into a plurality of areas, and extracts color coordinate values that are examples of representative values for each of the divided areas. The color coordinate value is extracted from the color pixel values constituting the pixel. The conversion from the color pixel value to the color coordinate value is calculated based on the following formula (2), for example.

The RGB color system represents a color based on the mixing amount of the three primary colors of R (700.0 nm), G (546.1 nm), and B (435.8 nm). The conversion formula to the XYZ color system which corrects the defect indicating the negative value of the RGB color system is the following formula (1).

Expressions (2) and (3) shown below are converted from the XYZ color system to the two-dimensional coordinate xy expression coordinates.

* RGB of the pixel value of the captured image is extracted, converted by these formulas, and converted to formula coordinates.

[Determining unit 63]
In the present embodiment, the determination unit 63 calculates whether or not the color coordinate value falls within a predetermined range of the color coordinate value, and pays attention to an area 209 (see FIG. 6D) having the color coordinate value that falls within the predetermined range. The region 201 is determined.

As shown in FIG. 6D, for example, when the subject 13 has a lesion such as a tumor, the determination unit 63 determines an area 209 having a color coordinate value characteristically present in the tumor as a predetermined color coordinate range. . The determination unit 63 sets the region 209 as the attention region 201 where the tumor exists. The predetermined color coordinate range may be set according to the part of the subject 13. Information on the color coordinate range corresponding to the target part may be stored and read as table data in a recording unit (not shown). The determination unit 63 may determine a range 211 that includes a color existing in a region other than the tumor in the subject 13.

The determining unit 63 may determine, for example, an area in which the red pixel value is equal to or greater than a predetermined value among the RGB values of the captured image 301 as the attention area 201. The determination unit 63 may determine, as the attention area 201, an area in which the values of a plurality of color pixels such as blue and green other than the red pixels are equal to or greater than a predetermined value among the RGB values of the captured image 301.

[Action]
[Lighting operation and imaging operation]
When the first operation unit is operated, the light source control unit 23 controls the light source 21 to emit primary light. The primary light emitted from the light source 21 passes through the light guide member 25, the demultiplexing unit 27, and the light guide member 25 and proceeds to the illumination unit 29. The light distribution angle of the primary light emitted from the light guide member 25 and entering the illumination unit 29 is narrow, and the primary light is a narrow light distribution. The light distribution half-value angle of the primary light is, for example, 15 degrees. In the illumination unit 29, the primary light passes through the transmission member 29b and irradiates the light conversion member 29a.

A part of the primary light is diffused by the diffusing particles. This light is referred to as primary diffused light that is secondary light SL. The primary diffused light has a different diffusion angle from the primary light incident on the illumination unit 29.

The remaining part of the primary light is absorbed by the phosphor and converted into light having a wavelength longer than that of the primary light. This light is referred to as converted light that is the secondary light SL. The converted light is emitted without directivity inside the light conversion member 29a.

As shown in FIGS. 6B and 6C, a part of the primary diffused light and the converted light travels in the direction opposite to the primary light incident on the illumination unit 29 inside the light conversion member 29a. To do. The first-order diffused light and converted light traveling in the opposite directions are reflected by the reflecting member 29c and travel forward of the light converting member 29a. The primary diffused light and the converted light are repeatedly performed by diffusing the diffusing particles and reflecting the reflecting member 29c. 6B and 6C, the primary diffused light and the converted light are emitted as the secondary light SL from the illumination unit 29 toward the light distribution adjusting illumination unit 90 in a state having a wide light distribution angle. . The light distribution half-value angle of the secondary light SL is, for example, around 125 degrees. The light distribution characteristic of the secondary light SL is symmetrical with respect to the optical axis.

The secondary light SL is incident on the optical element 93. The light distribution of the illumination light IL is adjusted by the relationship described later in the optical element 93. In the adjusted state, as shown in FIGS. 6B and 6C, the illumination light IL is emitted from the optical element 31 to the outside and illuminates the subject 13.

The illumination light IL is reflected and diffused by the subject 13, and the reflected light RL enters the imaging unit 41. When the second operation unit is operated, the imaging unit 40 is driven. The imaging unit 41 captures the reflected light RL, the image processing unit generates a captured image 301 based on the reflected light RL, and the display unit 50 displays the captured image 301.

[Adjustment of light distribution as optical characteristics]
The adjustment of light distribution will be described with reference to FIG. 6E.
As in the first embodiment, Steps 1, 2, and 3 are performed in order. Next, the extraction unit 61 extracts a color coordinate value and outputs the color coordinate value to the determination unit 63 (Step 21). Then, the determination unit 63 determines the region of interest 201 based on the color coordinate values extracted by the extraction unit 61 (Step 22). Step 6 is performed as in the first embodiment. In Step 6, the setting unit 67 outputs information related to the planned illumination area 205 to the control unit 80.

The control unit 80 controls the adjustment mechanism 70 based on this information. And the adjustment mechanism 70 adjusts the relative distance between the optical element 93 and the illumination part 29 based on control of the control part 80 (Step23). Then, Step 8 is performed.

In Steps 22 and 6, for example, in a state where the attention area 201 is larger than the illumination area 203 and the attention area 201 includes the illumination area 203, the illumination scheduled area 205 includes, for example, the inside of the attention area 201 and the illumination area 203. Is an external area. In this case, the illumination area 203 needs to be enlarged to approximate the attention area 201. For this reason, in Step 23, the ball screw of the adjusting mechanism 70 rotates in the second direction around the axis of the ball screw by the driving force, and the adjusting member 75 moves along the optical axis direction of the primary light. The light distribution adjustment illumination unit 90 held by the adjustment member 75 moves along the optical axis direction of the primary light with respect to the illumination unit 29 in conjunction with the adjustment member 75. As shown in FIG. 6B, the optical element 93 approaches the illumination unit 29, and the relative distance between the illumination unit 29 and the optical element 93 is shortened.

As shown in FIG. 6B, when the relative distance is short, most of the secondary light SL emitted from the illumination unit 29 passes through the optical element 93 and is emitted to the outside as illumination light IL. In this case, most of the secondary light SL emitted from the illumination unit 29 does not travel to the reflecting member 95 and is not reflected by the reflecting member 95. For this reason, the adjustment amount of the light distribution adjusting illumination unit 90 with respect to the secondary light SL is small, the light distribution angle of the illumination light IL is close to the light distribution angle of the secondary light SL, and the light distribution half-value angle of the illumination light IL. Is, for example, 120 degrees. Therefore, the illumination light IL is emitted from the light distribution adjustment illumination unit 90 as a wide light distribution. Then, the illumination area 203 is enlarged so as to approximate the attention area 201, and the planned illumination area 205 is eliminated along with the enlargement. As a result, in Step 8, the illumination planned area 205 is illuminated with the illumination light IL.

In Steps 22 and 6, for example, when the illumination area 203 is larger than the attention area 201 and the illumination area 203 includes the attention area 201, the illumination scheduled area 205 is the attention area 201. In this case, the illumination area 203 needs to be reduced so as to approximate the attention area 201. For this reason, in Step 23, the ball screw of the adjusting mechanism 70 rotates in the first direction around the axis of the ball screw by the driving force, and the adjusting member 75 moves along the optical axis direction of the primary light. The light distribution adjustment illumination unit 90 held by the adjustment member 75 moves along the optical axis direction of the primary light with respect to the illumination unit 29 in conjunction with the adjustment member 75. As shown in FIG. 6C, the optical element 93 is separated from the illumination unit 29, and the relative distance between the illumination unit 29 and the optical element 93 is increased.

As shown in FIG. 6C, when the relative distance is long, the component of the secondary light SL having a large angle formed with the optical axis in the secondary light SL emitted from the illumination unit 29 is reflected on the reflecting member 95. It travels and is reflected toward the optical element 93 by the reflecting member 95 so that the angle formed with the optical axis becomes small. For this reason, the adjustment amount of the light distribution adjusting illumination unit 90 with respect to the secondary light SL is large, and the light distribution angle of the illumination light IL is narrow. Therefore, the illumination light IL is emitted from the light distribution adjustment illumination unit 90 as a narrow light distribution. For this reason, the illumination area 203 is reduced so as to approximate the attention area 201, and unnecessary illumination light IL is eliminated along with the reduction. As a result, in Step 8, the attention area 201 which is the illumination scheduled area 205 is illuminated with the illumination light IL.

[effect]
In the present embodiment, the attention area 201 is determined based on the color coordinate value. For this reason, a specific part, for example, the periphery of a blood vessel can be easily determined as the attention area 201, and the illumination light IL can be illuminated without waste.

In the present embodiment, the light distribution of the illumination light IL applied to the planned illumination area 205 can be adjusted by the light distribution adjustment illumination unit 90 and the adjustment mechanism 70. In the present embodiment, the light distribution characteristic associated with the relative distance can be adjusted stepwise or continuously.

[Third Embodiment]
Hereinafter, only points different from the first embodiment will be described with reference to FIGS. 7A, 7B, 7C, 7D, and 7E. In the first and second embodiments, the illumination area 203 is enlarged or reduced by light distribution adjustment so that the illumination area 203 substantially matches the attention area 201. However, in this embodiment, the light quantity ratio of the primary light in the illumination areas 203a and 203b is constant, and the illumination area 203 is enlarged or reduced according to the light quantity of the illumination light IL, not the light distribution adjustment, and the illumination area 203 is illuminated. The position is adjusted by the mechanical structure.

[Constitution]
As shown in FIG. 7A, the endoscope system 10 is fixed to the fixing portion 101 while holding the illumination portion 29 and the fixing portion 101 fixed to the inner wall of the distal end portion 11 of the insertion portion, and is elastically deformable. And an elastic holding portion 103. One elastic holding unit 103 holds one illumination unit 29 so that the illumination light IL is not blocked by the elastic holding unit 103. For example, the elastic holding portion 103 has, for example, a ring shape, and the distal end portion of the illumination unit 29 engages with the hollow portion of the elastic holding portion 103. A part of the elastic holding part 103 is fixed to the fixing part 101. The fixing part 101 is disposed outside the elastic holding part 103.

In the present embodiment, one or more illumination units 29 are arranged. For example, it is preferable that two or more illumination units 29 are arranged. In this case, the illumination units 29 are arranged symmetrically with respect to each other with the imaging unit 41 as the center. The illumination part 29 is arrange | positioned on a concentric circle.

As shown in FIG. 7A and FIG. 7B, the adjustment mechanism 70 is arranged in the same number as the illumination unit 29 and in pairs with the illumination unit 29, and includes an inclined unit 110 that inclines the illumination unit 29 with respect to the central axis of the distal end portion 11. Have. In the present embodiment, the adjustment mechanism 70 adjusts the direction that is the optical characteristic of the illumination light IL by tilting. The inclined portion 110 is a working source that operates by a supply source 111 that supplies a current, an electromagnet 113 that is a drive source driven by the current supplied from the supply source 111, and a magnetic force that is a driving force generated by the electromagnet 113. Magnetic body 115.

The supply source 111 is controlled by the control unit 80.

The electromagnet 113 is disposed behind the magnetic body 115. The electromagnet 113 is arranged at a desired distance from the magnetic body 115 so that the magnetic force can act on the magnetic body 115.

The magnetic body 115 is disposed on the opposite side of the fixing unit 101 with the illumination unit 29 interposed therebetween in the elastic holding unit 103. The magnetic body 115 is disposed beside the illumination unit 29 and inside the elastic holding unit 103. When the illumination unit 29 is arranged symmetrically around the imaging unit 41, the magnetic body 115 is arranged between the illumination unit 29 and the imaging unit 41.

7C and 7D, the determination unit 63 determines the entire display image 303 displayed by the display unit 50 as the attention area 201.

[Adjustment of light distribution as optical characteristics]
The light distribution adjustment will be described with reference to FIG. 7E.
As in the first embodiment, Steps 1, 2, and 3 are performed in order. Next, the determination unit 63 determines the entire display image 303 as the attention area 201 (Step 31). Step 6 is performed as in the first embodiment. In Step 6, the setting unit 67 outputs information related to the planned illumination area 205 to the control unit 80. The control unit 80 controls the light source control unit 23 and the adjustment mechanism 70 based on this information.

The light source control unit 23 controls the amount of primary light output from the light source 21 based on the control of the control unit 80 (information on the planned illumination area 205). Thereby, the size of the illumination area 203 is adjusted according to the planned illumination area 205, and is enlarged or reduced as desired (Step 32). The size of the illumination area 203 does not need to be defined in advance, and may be adjusted according to the situation.

The illumination unit 29 is inclined with respect to the axial direction of the optical element 31 by the adjusting mechanism 70 (Step 33). Specifically, in the adjustment mechanism 70, the supply source 111 supplies current to the electromagnet 113. When the electromagnet 113 causes a magnetic force to act on the magnetic body 115 (the magnetic body 115 is attracted to or separated from the electromagnet 113), as shown in FIG. The illumination unit 29 is tilted with respect to the axial direction of the optical element 31. As a result, the emission direction of the illumination light IL changes. As shown in FIG. 7B, for example, when the electromagnet 113 attracts the magnetic body 115, the illumination unit 29 is inclined so that the optical axis of the illumination unit 29 approaches the central axis of the imaging unit 41. When the electromagnet 113 separates the magnetic body 115, the illumination unit 29 is tilted so that the optical axis of the illumination unit 29 is separated from the central axis of the imaging unit 41. The inclination angle increases in proportion to the current value.

As the illumination unit 29 is tilted, the illumination region 203 moves according to the tilt, as shown in FIGS. 7C and 7D. When the electromagnet 113 attracts the magnetic body 115, the illumination areas 203a and 203b approach each other. When the electromagnet 113 separates the magnetic body 115, the illumination areas 203a and 203b are separated from each other. As a result, the attention area 201 that is the planned illumination area 205 is illuminated with the illumination light IL (Step 8).

When the illumination area 203 substantially coincides with the attention area 201, it is necessary that the illumination area 203 does not protrude from the planned illumination area 205. For this reason, the illumination area 203 moves so that the area of the planned illumination area 205 is equal to or less than a predetermined ratio (for example, 10%) of the area of the attention area 201.

[effect]
In the present embodiment, the attention area 201 is a display image 303. For this reason, the illumination light IL can be illuminated on the entire captured image 301.

Since the illumination unit 29 is tilted and the illumination light IL is illuminated on the planned illumination area 205, the illumination light IL can be easily illuminated at a desired site to be observed.

Since two or more illumination units 29 are arranged, it is possible to illuminate a desired part to be observed with a plurality of illumination lights IL, and to observe a desired part to be observed in a bright state.

[Fourth Embodiment]
Hereinafter, only points different from the first embodiment will be described with reference to FIGS. 8A, 8B, 8C, and 8D. One or more illumination units 29 may be arranged.

[Constitution]
As shown in FIG. 8A, the adjustment mechanism 70 also serves as the light source control unit 23. In this case, the adjustment mechanism 70 adjusts the optical characteristics of the illumination light IL by adjusting the light quantity ratio of the primary light output from each light source 21.

When the amount of primary light is adjusted, the amount of primary light increases or decreases. As a result, the illumination area 203 expands or contracts around the optical axis of the illumination light IL.

For example, in the illumination area 203, the center of the illumination area 203 is bright and the periphery of the illumination area 203 is dark. When the illumination areas 203a and 203b have the same size and the illumination areas 203a and 203b have the same light amount, a part of the illumination area 203a overlaps with a part of the illumination area 203b as shown in FIG. 8B. In the captured image 301, the center of the captured image 301 is bright and the periphery of the captured image 301 is dark.

As shown in FIG. 8B, for example, when the attention area 201 exists only in a portion included in the illumination area 203b, the illumination area 203a is not necessary. For this reason, as shown to FIG. 8C, the illumination area | region 203a shrinks because the light quantity of the primary light radiate | emitted from the 1st illumination part 29 reduces. If necessary, the amount of primary light emitted from the second illumination unit 29 is reduced, so that the illumination region 203b of the second illumination unit 29 is reduced.

[Adjustment of light distribution as optical characteristics]
The adjustment of light distribution will be described with reference to FIG. 8D.
As in the first embodiment, Steps 1, 2, 3, 4, 5, and 6 are sequentially performed. In Step 6, the setting unit 67 outputs information related to the planned illumination area 205 to the control unit 80. The control unit 80 controls the light source control unit 23 based on this information. The light source control unit 23 controls the amount of primary light output from the light source 21 based on the control of the control unit 80 (information on the planned illumination area 205). Thereby, the size of the illumination area 203 is adjusted according to the planned illumination area 205, and is enlarged or reduced as desired (Step 32). As a result, the attention area 201 that is the planned illumination area 205 is illuminated with the illumination light IL (Step 8).

[effect]
In the present embodiment, the illumination area 203a (illumination light IL) that does not need to be illuminated can be cut according to the attention area 201, so that power consumption can be reduced.

[Fifth Embodiment]
Hereinafter, with reference to FIG. 1 and FIG. 9, only a different point from 1st Embodiment is described. In the embodiment described above, the determination unit 63 determines the attention area 201 based on any one of the contrast value, the color coordinate value, and the display image 303 of the display unit 50, which are specified values specified in advance. The specific method is not limited to the above. For example, the configurations shown in the first, second, and third embodiments may be combined, and any one of the contrast value, the color coordinate value, and the display image 303 of the display unit 50 that are representative values may be designated.

In this case, as shown in FIG. 9, Steps 1, 2, and 3 are sequentially performed as in the first embodiment.

Next, as illustrated in FIG. 9, the designation unit 120 designates any one of the designated values of the contrast value, the color coordinate value, and the display image 303 of the display unit 50 used for determining the attention area 201 ( Step 51).

As illustrated in FIG. 9, the determination unit 63 determines the attention area 201 based on the specified value specified by the specifying unit 120 (Step 52).
For example, when the designation unit 120 designates the contrast value, the designation unit 120 outputs the designation result to the extraction unit 61 as illustrated in FIG. The extraction unit 61 extracts a contrast value and outputs the contrast value to the determination unit 63. The determination unit 63 determines the attention area 201 based on the contrast value extracted by the extraction unit 61.
For example, when the designation unit 120 designates the color coordinate value, the designation unit 120 outputs the designation result to the extraction unit 61 as illustrated in FIG. The extraction unit 61 extracts the color coordinate value and outputs the contrast value to the determination unit 63. The determination unit 63 determines the attention area 201 based on the color coordinate values extracted by the extraction unit 61.
For example, when the designation unit 120 designates the display image 303 of the display unit 50, the designation unit 120 outputs the designation result to the determination unit 63 as illustrated in FIG. The determination unit 63 determines the entire display image 303 displayed by the display unit 50 as the attention area 201.

Then, as shown in FIG. 9, Steps 6, 7, and 8 are sequentially performed as in the first embodiment.

In the present embodiment, the designation unit 120 can perform appropriate light distribution adjustment according to the subject 13.

[Others]
In the first embodiment, the determination unit 63 determines the attention area 201 based on the contrast value extracted by the extraction unit 61. The adjustment mechanism 70 adjusts the relative distance between the illumination unit 29 and the optical element 31.
In the second embodiment, the determination unit 63 determines the attention area 201 based on the color coordinate values. The adjustment mechanism 70 adjusts the relative distance between the illumination unit 29 and the light distribution adjustment illumination unit 90.
In the third embodiment, the determination unit 63 determines the display image 303 as the attention area 201. The adjustment mechanism 70 tilts the illumination unit 29 to adjust the emission direction of the illumination light IL.
The combination of the determination unit 63 and the adjustment mechanism 70 in each embodiment is not limited to the above, and can be changed as appropriate.

The present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment.

Claims

An illumination unit that illuminates the subject with illumination light;
An imaging unit that images the subject based on the illumination light reflected from the subject;
An attention area determination unit that determines an attention area that is an area of interest for observation based on a captured image of the subject imaged by the imaging unit;
An illumination area identifying unit that identifies an illumination area, which is an area illuminated by the illumination light, based on the captured image;
Based on the region of interest and the illumination region, a planned illumination region setting unit that sets a planned illumination region that is a region where illumination of the illumination light is planned,
An adjustment mechanism that adjusts optical characteristics of the illumination light so that the illumination planned area is illuminated with the illumination light;
An endoscope system comprising:
Further comprising an extraction unit that divides the captured image into a plurality of regions and extracts a contrast value for each of the divided regions;
The attention area determination unit calculates whether or not the contrast value is higher than a predetermined value, and determines, as the attention area, an area having the contrast value calculated to be higher than the predetermined value. The endoscope system described.
Further comprising an extraction unit that divides the captured image into a plurality of regions and extracts color coordinate values for each of the divided regions;
The attention area determination unit calculates whether or not the color coordinate value falls within a predetermined range of the color coordinate value, and determines an area having the color coordinate value that falls within the predetermined range as the attention area. The endoscope system according to claim 1.
A display unit for displaying the captured image;
The endoscope system according to claim 1, wherein the attention area determination unit determines a display image displayed by the display unit as the attention area.
The illumination scheduled area setting unit is
In the state where the attention area is larger than the illumination area and the attention area includes the illumination area, an area calculated by subtracting the illumination area from the attention area is set as the illumination scheduled area,
In the state where the illumination area is larger than the attention area and the illumination area includes the attention area, the attention area is set as the illumination scheduled area,
The endoscope system according to claim 1, wherein the adjustment mechanism adjusts the optical characteristics of the illumination light so that an area of the illumination scheduled area satisfies a predetermined criterion.
The endoscope system according to claim 5, wherein the illumination area specifying unit specifies an area having a brightness equal to or higher than a predetermined brightness in the captured image as the illumination area.
The illumination unit is arranged in one or more illumination units that illuminate the subject with the illumination light, and the same number as the illumination units and in pairs with the illumination unit, and an optical through which the illumination light emitted from the illumination unit passes. Having an element,
The endoscope system according to claim 6, wherein the adjustment mechanism adjusts the optical characteristic of the illumination light by adjusting a relative distance between the illumination unit and the optical element.
The lighting unit is:
One or more illumination units that emit the illumination light;
A light distribution adjustment illumination unit that receives the illumination light emitted from the illumination unit, adjusts the light distribution characteristic of the received illumination light, and illuminates the subject with the illumination light having the adjusted light distribution characteristic When,
Have
The endoscope system according to claim 6, wherein the adjustment mechanism adjusts the optical characteristic of the illumination light by adjusting a relative distance between the illumination unit and the light distribution adjustment illumination unit.
The illumination unit has one or more illumination units that irradiate the subject with the illumination light,
The adjustment mechanism is arranged in the same number as the illumination unit and in pairs with the illumination unit, and has an inclined unit that inclines the illumination unit,
The endoscope system according to claim 6, wherein the adjustment mechanism adjusts the optical characteristic of the illumination light by tilting.
The lighting unit is:
A plurality of light sources that emit primary light;
A plurality of illumination units arranged in the same number as the light sources and paired with the light sources, converting the optical characteristics of the primary light, and emitting the primary light converted the optical characteristics as the illumination light to the subject When,
Have
The endoscope system according to claim 6, wherein the adjustment mechanism adjusts the optical characteristic of the illumination light by adjusting a light amount ratio of the primary light emitted from each light source.
The lighting unit is:
A light source that emits primary light;
A light guide member for guiding the primary light;
One or more illumination units that convert the optical characteristics of the primary light guided by the light guide member, and emit the primary light having the converted optical characteristics as the illumination light to the subject;
The endoscope system according to claim 1, comprising:
The endoscope system according to claim 11, wherein the adjustment mechanism adjusts the optical characteristics of all the illumination units simultaneously in conjunction with all the illumination units.
The endoscope system according to claim 11, wherein the illumination units of the illumination unit are provided symmetrically about the imaging unit of the imaging unit.
An extraction unit that divides the captured image into a plurality of regions and extracts a contrast value or a color coordinate value for each of the divided regions;
A display unit for displaying the captured image;
A designation unit that designates any one of the contrast value, the color coordinate value, and the display image of the display unit that are used for determining the region of interest;
Further comprising
The attention area determination unit determines the attention area based on the designated value designated by the designation unit,
When the specifying unit specifies the contrast value, the attention area determining unit calculates whether or not the contrast value is higher than a predetermined value, and has the contrast value calculated to be higher than the predetermined value. Determining a region as the region of interest;
When the designation unit designates the color coordinate value, the attention area determination unit calculates whether the color coordinate value falls within a predetermined range of the color coordinate value, and enters the predetermined range. Determining a region having a color coordinate value as the region of interest;
The endoscope system according to claim 1, wherein, when the designation unit designates the display image, the attention area determination unit determines the display image as the attention area.
12. The endoscope system according to claim 11, wherein the attention area determination unit determines the attention area based on an area designated by a designation section from a display image displayed on a display section.
An illumination step of emitting illumination light from the illumination unit and illuminating the illumination light on a subject;
An imaging step of imaging the subject by an imaging unit based on the illumination light reflected from the subject;
A specifying step of specifying an illumination area, which is an area illuminated by the illumination light, by an illumination area specifying unit based on a captured image of the subject imaged by the imaging unit;
A determination step of determining a region of interest, which is a region of interest for observation based on the captured image, by a region of interest determination unit;
Based on the attention area and the illumination area, a setting step of setting an illumination scheduled area that is an area where illumination of the illumination light is scheduled by an illumination scheduled area setting unit;
An adjustment step of adjusting an optical characteristic of the illumination light by an adjustment mechanism so that the illumination scheduled area is illuminated with the illumination light;
An endoscopic system control method comprising: