JP6736550B2 - Endoscope system and control method for endoscope system - Google Patents

Description

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

For example, Patent Document 1 discloses an endoscope having an elongated insertion portion. The insertion portion contains a light guide that transmits the light emitted from the light source, and an illumination optical system that is disposed in front of the emission end portion of the light guide and has 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 surface of the light guide and inclined with respect to the emission end surface.

In a thin endoscope having a wide viewing angle, even when a light guide having a small NA such as a quartz light guide is used, 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. Therefore, if the illumination area of the illumination light is set narrower in advance corresponding to the narrow viewing angle, when the viewing angle becomes wider according to observation, the attention area, which is the area of interest for observation, is larger than the illumination area. Also becomes larger, and the attention area includes the illumination area. In this case, there is a possibility that the illumination light may not be sufficiently distributed to the illumination scheduled region that is inside the attention region and outside the illumination region and is a region where the illumination light is scheduled to be illuminated.
On the contrary, if the illumination area of the illumination light is set wide in advance corresponding to a wide viewing angle, the illumination area becomes larger than the attention area and the illumination area becomes Include a region. In this case, the area existing inside the illumination area and outside the attention area and illuminated with the illumination light is an area where the illumination light is wastefully illuminated.
Therefore, the illumination light cannot be sufficiently distributed according to the viewing angle, and the illumination light is wasted.
It is desired to sufficiently distribute the illumination light without being affected by the viewing angle and to suppress the waste of the illumination light.

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

One aspect of an endoscope system of the present invention is an endoscope system, which is an illumination unit that illuminates a subject with illumination light, and an imaging unit that captures the subject based on the illumination light reflected from the subject. A region of interest illuminated by the illumination light on the basis of the captured image of the subject captured by the image capturing unit, and a region of interest determining unit that determines a region of interest in the captured image. An illumination area specifying unit that specifies a certain illumination area, and a target area setting unit that sets a target area illuminated by the illumination light, based on the inclusion relationship between the determined attention area and the specified illumination area. And an adjusting mechanism that adjusts the optical characteristic of the illumination light so that the illumination region is approximated to the region of interest based on the set information about the target region.

One aspect of a control method of an endoscope system of the present invention is a control method of an endoscope system, wherein a control unit of the endoscope system controls an illumination unit to emit illumination light to emit the illumination light. An illumination step of illuminating a subject with light, an imaging step of controlling an image capturing unit to capture an image of the subject based on the illumination light reflected from the object, and an illumination area specifying unit to control the illumination light. A specific step of specifying an illumination area, which is an area illuminated by the light source, based on the captured image of the captured subject, and controlling the attention area determination unit to determine the focus in the captured image based on the captured image. By controlling the determination step of determining the area and the target area setting unit, the target area illuminated by the illumination light is set based on the determined inclusion relationship between the attention area and the identified illumination area. A setting step and an adjusting step of controlling an adjusting mechanism to adjust the optical characteristic of the illumination light so as to approximate the illumination area to the attention area based on the set information about the target area are performed. ..

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

FIG. 1A is a schematic diagram of an endoscope system according to a first embodiment of the present invention. FIG. 1B is a diagram showing a configuration of the illumination unit and the adjustment mechanism. FIG. 1C is a front view of the distal end portion of the insertion portion. FIG. 2A is a diagram showing that the 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 showing that the planned illumination area shown in FIG. 2A is illuminated with illumination light. FIG. 2C is a diagram showing that the planned illumination 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 showing that the illumination planned area shown in FIG. 2C is illuminated with illumination light. FIG. 3A is a diagram illustrating the principle of adjusting the light distribution. FIG. 3B is a diagram illustrating the principle of adjusting the light distribution. FIG. 4 is a flowchart showing the operation of adjusting the light distribution in the first embodiment. FIG. 5 is a flowchart showing the operation of adjusting the light distribution in the modification of the first embodiment. FIG. 6A is a diagram showing 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 showing a state in which the relative distance between the illumination unit and the optical element of the light distribution adjustment illumination unit is shortened and the illumination light is emitted with a wide light distribution. FIG. 6C is a diagram showing a state in which the relative distance between the illumination unit and the optical element of the light distribution adjustment illumination unit becomes long and the 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 the operation of adjusting the light distribution in the second embodiment. FIG. 7A is a diagram showing a configuration of an illumination unit and an adjustment mechanism according to the third embodiment of the present invention. FIG. 7B is a diagram showing the illuminating section tilted by the adjusting mechanism. FIG. 7C is a diagram showing a positional relationship between the attention area, the illumination area, and the planned illumination area before the illumination section is inclined. FIG. 7D is a diagram showing a positional relationship among the attention area, the illumination area, and the planned illumination area after the illumination unit is tilted. FIG. 7E is a flowchart showing the operation of adjusting the light distribution in the third embodiment. FIG. 8A is a schematic diagram of an endoscope system according to the fourth embodiment of the present invention. FIG. 8B is a diagram showing a positional relationship among the attention area, the illumination area, and the illumination planned area before the light amount is adjusted. FIG. 8C is a diagram showing a positional relationship between the attention area, the illumination area, and the illumination scheduled area in the state after the light amount is adjusted. FIG. 8D is a flowchart showing the operation of adjusting the light distribution in the fourth embodiment. FIG. 9 is a flowchart showing the 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. In addition, in some of the drawings, some of the members are not shown for the sake of clarity.

[First Embodiment]
[Constitution]
The first embodiment will be described with reference to FIGS. 1A, 1B, 1C, 2A, 2B, 2C, 2D, 3A, 3B, and 4.
As shown in FIG. 1A, the endoscope system 10 includes an illumination unit 20 that illuminates the subject 13 with the illumination light IL from the distal end 11 of the insertion portion provided in the endoscope (not shown), and the reflection reflected from the subject 13. The 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 image capturing 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 controller 23 that controls the light source 21, a plurality of light guide members 25 that guide the primary light, and a light source 21. And a demultiplexing unit 27 that demultiplexes the primary light emitted from the optical system 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 the illumination light IL, The optical elements 31 are arranged in the same number as the illumination units 29 and are paired with the illumination units 29, and the optical elements 31 transmit the illumination light IL emitted from the illumination units 29.

[Light source 21]
The light source 21 has, for example, a laser diode that emits blue laser light. The central 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 the housing provided outside the endoscope or may be provided inside the endoscope.

[Light source control unit 23]
The light source control unit 23 supplies the light source 21 with electric power necessary for driving the light source 21. The light source controller 23 supplies the light source 21 with power equal to or higher than a predetermined threshold power and proportional to the light amount of the illumination light IL, or supplies power according to the drive interval of the light source 21 to the light source 21. The light source control unit 23 supplies electric power by operating a first operation unit (not shown). The first operation section is operated by the operator to instruct to turn on or off the emission of the illumination light IL. When the light source 21 is provided inside the housing, the light source controller 23 and the first operation unit are provided inside the housing. 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 on 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 has, for example, an optical fiber. The core diameter of the optical fiber is, for example, 50 μm and the numerical aperture FNA is 0.2, and the optical fiber is a multimode optical fiber. When the light source 21 is provided inside the housing, the light guide member 25 is provided inside the housing and inside the endoscope. When the light source 21 is provided inside the endoscope, the light guide member 25 is provided inside the endoscope.

[Demultiplexing unit 27]
As shown in FIG. 1A, the demultiplexing unit 27 demultiplexes the primary light according to the number of illumination units 29. In the present embodiment, for example, two illumination units 29 are provided, so 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 this 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 portion, the demultiplexing portion 27 may be provided inside the housing portion or inside the endoscope. For example, when the light source 21 is provided inside the endoscope, the demultiplexing unit 27 is provided inside the endoscope.

[Illumination unit 29]
As shown in FIG. 1A, the illumination unit 29 is fixed inside the distal end portion 11 of the insertion unit by, for example, an adhesive. When the illuminating unit 29 receives the primary light guided by the light guide member 25, the illuminating 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 that of the primary light and emits the illumination light IL. In this way, 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 it does not change 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 emission end face of the light guide member 25 and the light conversion member 29a in the traveling direction of the primary light, and the traveling direction of the primary light. At the light emitting end face of the light guide member 25 and the transmissive member 29b optically connected to the light converting 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. It further has a member 29d.

[Light conversion member 29a]
As shown in FIG. 1B, the light conversion member 29a is provided in front of the transmissive member 29b in the traveling direction of the primary light, and is optically connected to the transmissive member 29b. The light conversion member 29a has a truncated cone shape. The truncated cone expands in diameter in 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 transmissive member 29b, and the base end surface of the light conversion member 29a directly contacts the front end surface of the transmissive 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 in the traveling direction of the primary light.

The light conversion member 29a emits the primary light that has entered the light conversion member 29a as illumination light IL toward the front, which is the subject 13 side, and the rear, which is 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 primary light and converts the primary light into converted light having a wavelength longer than the wavelength of the primary light. The phosphor is, for example, powder represented by YAG:Ce. The phosphor has a function of absorbing the primary light in the blue wavelength range and converting the wavelength of the primary light into yellow fluorescence which is the illumination light IL. Further, since the yellow fluorescent light is emitted without directivity, the fluorescent substance also has a diffusion function. The encapsulating member collectively contains the phosphors in a state where the powdery phosphors are dispersed in the encapsulating 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 distribution angle of the primary light without changing the wavelength of the primary light. The diffusing member emits the diffused light as the illumination light IL. The diffusing member is fine particles 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 diffusing members in a state where the diffusing members are dispersed in each other.

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 for the primary light and the illumination light IL.

The refractive index of the diffusing member is different from the refractive index of the sealing member. For example, the refractive index of the diffusing member is higher than that of the sealing member, and is preferably 1.5 or more. As a result, the diffusing 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 converting member 29a is 0.1 mm. 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 transmissive member 29b has a property of transmitting the primary light and the illumination light IL. The transmissive member 29b is formed of glass having high transmissivity or silicone resin having high transmissivity. The transparent member 29b has a truncated cone shape. The truncated cone expands in diameter in the traveling direction of the primary light.

[Reflecting member 29c]
The reflection member 29c specularly or diffusely reflects the primary light and the incident light incident on the reflection member 29c. The reflecting member 29c may be scattered and reflected. The incident light is the illumination light IL emitted rearward from the light conversion member 29a. The reflection member 29c is a thin film of a 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 transmissive 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 columnar shape. For example, the second hole 29f has a truncated cone shape. The truncated cone expands in diameter in the traveling direction of the primary light. A reflection 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 portion 29e and the light conversion member 29a and the transmissive member 29b are engaged with the second hole portion 29f, the holding member 29d is connected to the light guide member 25 and the light conversion member 29a. The transparent member 29b is held. As a result, the light guide member 25 is optically connected to the transmissive member 29b, the transmissive member 29b is optically connected to the light conversion member 29a, and the reflective member 29c is provided on the side surface of the light conversion member 29a and the side surface of the transmissive member 29b. Optically connected to. When the holding member 29d holds the light converting member 29a, the front end surface of the light converting member 29a is provided on the same plane as the front end surface of the holding member 29d.

The taper angle of the second hole 29f, the light converting member 29a, and the transmitting 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 this embodiment, for example, the taper angle is 25 degrees. As a result, the illumination light IL that is non-directional fluorescence and the illumination light IL that is 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 for one illuminating section 29, and the optical element 31 is arranged in front of the illuminating section 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 inside the distal end portion 11 of the insertion portion by an adjusting mechanism 70 described later. Each optical element 31 can be moved in the axial direction of the optical element 31 by the adjusting mechanism 70 at the same time, and moves toward or 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 adjusting mechanism 70.

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

The imaging unit 41 has, for example, a CCD or 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 FIGS. 1A, 1B, and 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 with the imaging unit 41 as the center. The illumination units 29 may be provided asymmetrically so that the observation is optimally performed.

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

[Representative value extractor]
As shown in FIG. 1A, the endoscope system 10 extracts a representative value indicating a state of pixel values of a captured image 301 (see FIGS. 2A, 2B, 2C, and 2D) captured by the image capturing unit 40. It further has a section (hereinafter referred to as an extraction section 61). In the present embodiment, the extraction unit 61 extracts a contrast value, which is an example of a representative value. The extraction unit 61 starts extraction after the imaging unit 40 starts the imaging operation, for example.

The extraction unit 61 receives the captured image 301 including the pixel value information of the blue pixel, the green pixel, and the red pixel from the imaging unit 40. The extraction unit 61 divides the captured image 301 into a plurality of areas. The extraction unit 61 extracts a high frequency component of a pixel with a bandpass filter for each of the divided areas. The extraction unit 61 integrates the extracted high frequency components to extract a contrast value for each region. In this way, the extraction unit 61 divides the captured image 301 into a plurality of areas and extracts the contrast value for each of the divided areas.

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

[Attention area determination unit]
As shown in FIG. 1A, the endoscope system 10 has an attention area 201 (FIGS. 2A, 2B, 2C, It further includes an attention area determination unit (hereinafter, referred to as determination unit 63) that determines 2D reference).

The determining unit 63 calculates whether the contrast value extracted by the extracting unit 61 is higher than a predetermined value. The determination unit 63 determines the area having the contrast value calculated as higher than the predetermined value as the attention area 201. For example, when the subject 13 is a tumor, on the surface of the site where blood vessels are present in the tumor, the unevenness present on this surface is more finely present than the site where the tumor is not present. The contrast value becomes large in the region where the unevenness exists, and becomes small in the region where the unevenness does not exist. The predetermined value is set based on the maximum contrast value on the captured image 301. Thereby, the determination unit 63 can stably determine the attention area 201. The predetermined value may be set by accumulating 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 and concave portions are present, at least a part of this portion is determined as the attention area 201.

The determination 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 portion having a high contrast value is separated into a plurality of discontinuous areas, the determining unit 63 may determine one area including all the portions having 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 is set to have the smallest area while the attention area 201 includes all the portions having high contrast values.

The determination unit 63 may determine the attention area 201 so that the edge of the captured image 301 is excluded from the attention area 201. When both ends are dark, the determining unit 63 may perform the processing in which the contrast value shows the original value.

[Illumination area specification part]
As shown in FIG. 1A, the endoscope system 10 is an illumination device that identifies 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 specifying unit 65 specifies an area having a brightness equal to or higher than a predetermined brightness in the captured image 301 as the illumination area 203. The identifying unit 65 calculates the brightest pixel value (hereinafter, the brightest pixel value) in the captured image 301. The identifying unit 65 calculates, from within the captured image 301, a pixel value (hereinafter, referred to as a predetermined pixel value) having a brightness of a predetermined ratio of the brightness of the brightest pixel value. The identifying unit 65 identifies an area having a predetermined pixel value as the illumination area 203. The illumination area 203 is an area having a brightness value equal to or higher than a predetermined brightness value corresponding to the brightness required for observation in the captured image 301. The identifying unit 65 may identify 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 an illumination region 203a, the illumination region 203 corresponding to the other illumination unit 29 is referred to as an illumination region 203b, and the illumination region 203a, 203b is collectively referred to as an illumination area 203.

The specifying unit 65 may specify, as the illumination area 203, an area having a brightness that allows the image pickup unit 40 to output a signal characteristic desired by the image pickup unit 40.

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

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 planned illumination area 205 is, for example, inside the attention area 201 and the illumination area 203. Is an area outside of. The planned illumination area 205 is an area that needs to be illuminated but is not actually illuminated. In this case, the scheduled illumination area 205 is the logical difference between the attention area 201 and the illumination area 203. Therefore, the setting unit 67 sets the area calculated by subtracting the illumination area 203 from the attention area 201 as the planned illumination area 205.
As shown in FIG. 2C, 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 planned illumination area 205 is the attention area 201. Therefore, the setting unit 67 sets the attention area 201 as the planned illumination area 205.
The processes in the extracting unit 61, the determining 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 equipped with an electronic circuit such as an ASIC (Application Specific Integrated Circuit). Alternatively, a general-purpose processor such as a CPU (Central Processing Unit) may load various programs to execute the processing.

[Adjustment mechanism 70 and control unit 80]
As shown in FIG. 1A, in the endoscope system 10, the 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, the light source controller 23, and the adjustment mechanism. And a control unit 80 that controls the entire endoscope system 10 including 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. Then, the image pickup unit 40 is driven.

The adjustment mechanism 70 adjusts the optical characteristics of the illumination light IL so that the area of the planned illumination region 205 satisfies a predetermined standard.
As illustrated 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 the area of the scheduled illumination area 205 and calculates the area. The adjusting mechanism 70 adjusts the light distribution based on the result.
In this case, for example, the control unit 80 controls the optical characteristic of the illumination light IL via the adjustment mechanism 70 so that the area of the planned illumination area 205 shown in FIG. 2A is equal to or smaller 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 planned illumination area 205 is almost eliminated as shown in FIG. 2B. Almost elimination of the planned illumination area 205 indicates that the area not illuminated with the illumination light IL is almost eliminated. The illumination light IL illuminates the entire attention area 201 by setting the predetermined ratio to be higher.
In order to eliminate the planned illumination area 205 as shown in FIG. 2B, the control unit 80 controls the adjusting mechanism 70, and the adjusting mechanism 70 adjusts the light distribution in the optical characteristic of the illumination light IL by the control. By this adjustment, the illumination area 203 is enlarged so as to approximate the area of interest 201. When the illumination area 203 expands and the area of the planned 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 the hill-climbing control using the area as an evaluation value so that the area of the planned illumination area 205 becomes the smallest.

Note that, 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 controls the attention area 201, which is the illumination scheduled area 205. The area is calculated, and the adjusting mechanism 70 adjusts the light distribution based on the calculation result.
In this case, the control unit 80 sets the illumination light IL via the adjustment mechanism 70 so that the area of the area 207 (see FIG. 2C) that is equal to or larger than the attention area 201 and equal to or smaller than the illumination area 203 is equal to or smaller than a predetermined ratio of the area of the attention area 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 region 207 is almost eliminated as shown in FIG. 2D. The almost elimination of the region 207 indicates that the useless illumination light IL is almost eliminated. By setting the predetermined ratio to be higher, 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 area of interest 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 drive force output from the drive source 71, and a drive force 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 on the adjusting 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 adjusting member 75 holds the optical element 31 so that the optical element 31 is arranged 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 about the axis of the ball screw due to the driving force, the adjusting member 75 moves along the axial direction of the optical element 31 due to the rotation of the ball screw. The optical element 31 held by the adjusting member 75 moves in association with the adjusting member 75 with respect to the illumination unit 29 along the axial direction of the optical element 31. As a result, the relative distance between the illumination unit 29 and the optical element 31 is adjusted, and the adjustment of this relative distance adjusts the light distribution, which is the optical characteristic of the illumination light IL. Then, the illumination area 203 is enlarged or reduced so as to be close to the attention area 201, the planned illumination area 205 is eliminated with the enlargement, and the area 207 is eliminated with the reduction. As a result, the planned illumination area 205 illuminates the illumination light IL. To be 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 refers to the central axis of the primary light emitted from the tip surface of the light guide member 25 connected to the transmissive member 29b.

As shown in FIG. 1B, the illumination unit 29 is fixed, the adjusting member 75 holds the optical element 31, and the adjusting member 75 moves, whereby the optical element 31 moves. Then, 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 adjusting member 75 may hold the illuminating unit 29, and the illuminating unit 29 may move with respect to the optical element 31 by moving the adjusting member 75. 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 the adjustment member 75 may move so that at least one of the illumination unit 29 and the optical element 31 moves with respect to the other. .. Thereby, the relative distance may be adjusted.
In this way, the adjustment mechanism 70 adjusts the relative distance between the illumination unit 29 and the optical element 31 to adjust the optical characteristics of the illumination light IL. 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 capturing an image. In the present embodiment, the one adjustment mechanism 70 works together with all the illumination units 29 to simultaneously adjust the optical characteristics of the illumination light IL emitted from all the illumination units 20.

[Action]
[Illumination 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 travels to the illumination unit 29. In the illumination unit 29, the primary light passes through the transmissive member 29b and irradiates the light conversion member 29a.

When the light conversion member 29a has 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 called converted light. The remaining part of the primary light is diffused by the diffusing particles. This light is called diffused light. It is preferable that the light distribution characteristics of the converted light and the light distribution characteristics 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 the 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 from the optical element 31 toward the outside and illuminates 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 image capturing 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 of adjusting light distribution, which is an optical characteristic]
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 the point light source located 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 the focal length F of the optical element 31.
The distance from the center of the optical element 31 to the emission end face of the illumination section 29 is defined as the distance L1.
The 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 the 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.

When L1<F, the distance L2 is calculated by the following formula (2) for the focal length F, the distance L1, and the distance L2.
1/L1 + 1/L2 = 1/F... Formula (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.

As described above, when the distance L1 is shorter than the focal length F, when the ball screw in the adjusting mechanism 70 rotates in the first direction around the axis of the ball screw by the driving force, the adjusting member 75 moves along the axial direction of the optical element 31. And moves in a direction away from the illumination unit 29. Then, the optical element 31 held by the adjusting member 75 moves along the axial direction of the optical element 31 with respect to the illuminating unit 29 in conjunction with the adjusting member 75, and separates from the illuminating unit 29. As a result, 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 expanded, and the illumination area 203 is expanded as shown in FIG. 2B. Then, the illumination area 203 is enlarged so as to be close to the attention area 201, and the planned illumination area 205 is eliminated with the expansion, and as a result, the planned illumination area 205 is illuminated with the illumination light IL.

Further, when the distance L1 is longer than the focal length F, when the ball screw in the adjusting mechanism 70 rotates about the axis of the ball screw in the second direction opposite to the first direction due to the driving force, the adjusting member 75 causes the optical element to move. It moves in a direction approaching the illumination unit 29 along the axial direction of 31. The optical element 31 held by the adjusting member 75 moves in the axial direction of the optical element 31 with respect to the illuminating unit 29 in association with the adjusting member 75, and approaches the illuminating unit 29. As a result, 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 increased. Therefore, the light distribution angle of the illumination light IL is narrowed, the illumination region 203 is reduced, and the region 207 is narrowed, as shown in FIG. 2D. Then, the illumination area 203 is reduced so as to be close to the attention area 201, and unnecessary illumination light IL is eliminated in accordance with the reduction, and as a result, the attention area 201, which is the planned illumination area 205, is illuminated with the illumination light IL.

[Adjustment of light distribution, which is an optical characteristic]
Adjustment of light distribution 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 the 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 captures an image of the subject 13 illuminated with the illumination light IL according to 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 image capturing 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 determination unit 63 determines the attention area 201 based on the contrast value extracted by the extraction unit 61 (Step 5).

The setting unit 67 sets the planned 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 about the planned illumination area 205 to the control unit 80.

The control unit 80 controls the adjustment mechanism 70 based on this information. Then, the adjusting mechanism 70 adjusts the relative distance between the optical element 31 and the illumination unit 29 based on the control of the control unit 80 (Step 7). As a result, the planned illumination area 205 is illuminated with the illumination light IL (Step 8).

In Steps 5 and 6, as shown in FIG. 2A, for example, when the attention area 201 is larger than the illumination area 203 and the attention area 201 includes the illumination area 203, the planned illumination area 205 is, for example, the attention area. An area inside 201 and outside the illumination area 203. Then, the illumination area 203 needs to be enlarged so as to approximate the area of interest 201. For this reason, as described above, in Step 7, the optical element 31 is adjusted so as to be separated from the illumination unit 29, and the relative distance L1 is long and the distance L2 is short. As a result, the light distribution angle of the illumination light IL is widened, and the illumination area 203 is enlarged so as to approximate the attention area 201 as shown in FIG. 2B, and the planned illumination area 205 is eliminated along with the enlargement. As a result, in Step 8, the planned illumination area 205 is illuminated with the illumination light IL. When the illumination area 203 expands and the area of the planned illumination 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, for example, as shown in FIG. 2C, 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 planned illumination area 205 is the attention area 201. .. Then, it is necessary to reduce the illumination area 203 so as to approximate the area of interest 201. Therefore, as described above, in Step 7, the optical element 31 approaches the illumination unit 29, the relative distance L1 is adjusted to be short, and the distance L2 is adjusted to be long. As a result, the light distribution angle of the illumination light IL is narrowed, 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 be close to the attention area 201, and useless illumination light IL is eliminated in accordance with the reduction. As a result, in Step 8, the attention area 201, which is the planned illumination 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 ends. When the endoscope system 10 observes another subject 13, the operations of Step 1 to Step 8 are repeated in this order. Note that, during observation, the operations of Step 2 to Step 8 may always be repeatedly performed in this order.

[effect]
In the present 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. As a result, in the present embodiment, the illumination light IL can be sufficiently distributed without being affected by the viewing angle, and waste of the illumination light IL can be suppressed.

In the present embodiment, the attention area 201 is determined based on the contrast value. For example, when the subject 13 is a tumor, the contrast value is large in the area where the blood vessel exists in the tumor and where the unevenness exists. Therefore, the convex and concave portions can be illuminated with the illumination light IL reliably and without waste.

[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 area 201 based on the area designated by the designation 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 the subject 13 that is particularly noticeable from the image displayed on the display unit 50. When the designating unit 120 is a mouse, the designating unit 120 designates, from the image displayed on the display unit 50, the starting point at the tip of the mouse arrow and the ending point diagonal to the starting point. The designation unit 120 designates a region formed by the start point and the end point. The determination unit 63 determines this designated area as the attention area 201. Alternatively, the designating unit 120 designates the starting point with the tip of the arrow of the mouse, and designates a region having an arbitrary radius with the starting point as the center point. The determination unit 63 determines this designated area as the attention area 201. When the designating unit 120 is a keyboard, the designating unit 120 designates the rectangular area by designating the XY coordinates of the diagonal points of the rectangle from the image displayed on the display unit 50, or the XY coordinates of the center point. This specifies a circular area. The determination unit 63 determines this area as the attention area 201.

In this modified example, after Steps 1, 2, and 3 are performed in order, 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 area designated by the designation unit 120 as the attention area 201 (Step 12). Next, Steps 6, 7, and 8 are carried out in order.

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

[Second Embodiment]
Hereinafter, with reference to FIG. 6A, FIG. 6B, FIG. 6C, FIG. 6D, and FIG. 6E, only the points different from the first embodiment will be described. It should be noted that at least one illumination unit 29 may be arranged. In the first embodiment, the light emitted from the illumination unit 29 is defined as the illumination light IL, but in the present embodiment, the light emitted from the illumination unit 29 is the secondary light SL (FIGS. 6B and 6C). And), 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 shown in FIG. 6A, the illumination unit 20 receives the secondary light SL emitted from the illumination unit 29, adjusts the light distribution characteristic of the received secondary light SL, and has the adjusted light distribution characteristic. The light distribution adjustment illumination unit 90 that emits the light IL to the outside is further included. The light distribution characteristic of the secondary light SL emitted from the illumination unit 29 is fixed. The light distribution adjustment lighting units 90 are arranged in the same number as the lighting units 29 and in pairs with the lighting units 29.

As shown in FIGS. 6B and 6C, the light distribution adjustment illumination unit 90 is movable by the adjustment mechanism 70 along the optical axis direction of the primary light with respect to the illumination unit 29. The optical axis of the primary light refers to the central axis of the primary light emitted from the tip surface of the light guide member 25 connected to the transmissive member 29b. The light distribution adjustment illumination unit 90 changes the adjustment amount of the light distribution characteristic according to the movement amount.

As shown in FIG. 6A, the light distribution adjusting illumination unit 90 includes a hollow member 91 in which the illumination unit 29 is arranged, an optical element 93 provided in the hollow member 91, and a reflecting 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 portion 91a and a second hole portion 91b. The first hole 91a is provided coaxially with the second hole 91b and communicates with the second hole 91b. For example, the first hole portion 91a has a columnar shape. For example, the second hole 91b has a truncated cone shape. The truncated cone expands in diameter in the traveling direction of the primary light. The illumination unit 29 is inserted into the first hole portion 91a and the second hole portion 91b. The first hole portion 91 a and the second hole portion 91 b are larger than the lighting unit 29. The hollow member 91 is connected to the adjusting 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 adjustment illumination unit 90 is transmitted. The optical element 93 is formed of, for example, glass having high transmittance. The optical element 93 has, for example, a cylindrical shape. The optical element 93 is fixed to the distal end surface of the hollow member 91 by adhesion so as to be arranged in front of the illumination unit 29, and covers the second hole 91b.

[Reflecting 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 reflecting member 95 specularly or diffusely reflects the incident light that has entered the reflecting member 95. The reflection member 95 may be scattered and reflected. This incident light is the secondary light SL including fluorescence and diffused light. The reflecting member 95 is a thin film of metal 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, in the adjustment member 75, the illumination section 29 is inserted into the first hole section 91a and the second hole section 91b, the optical element 93 is arranged in front of the illumination section 29, and the light distribution adjustment illumination unit 90 is provided. Holds the light distribution adjusting illumination unit 90 so that the light is arranged coaxially with the optical axis of the primary light.

As shown in FIGS. 6B and 6C, when the ball screw rotates about the axis of the ball screw by the driving force, the adjusting member 75 moves along the optical axis direction of the primary light due to the rotation of the ball screw. Then, the light distribution adjusting illumination unit 90 held by the adjusting member 75 moves in association with the adjusting member 75 along the optical axis direction of the primary light with respect to the illumination unit 29. 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 to the attention area 201, the planned illumination area 205 is eliminated with the enlargement, or the area 207 is eliminated with the reduction, and as a result, the planned illumination area 205 changes 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, whereby the light distribution adjustment illumination unit 90 moves. Then, 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 illumination unit 29 may move with respect to the light distribution adjustment illumination unit 90 as the adjustment member 75 moves. .. 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 the adjustment member 75 moves to cause at least one of the illumination unit 29 and the light distribution adjustment illumination unit 90 to the other. You may move. Thereby, the relative distance may be adjusted.
In this way, the adjustment mechanism 70 adjusts the relative distance between the illumination unit 29 and the light distribution adjustment illumination unit 90 to adjust the optical characteristics of the illumination light IL. 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, which are an example of representative values, for each of the divided areas. The color coordinate value is extracted from the color pixel values forming the pixel. The conversion from the color pixel value to the color coordinate value is calculated, for example, based on the following equation (2).

The RGB color system expresses a color based on a mixed amount of 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 of the RGB color system showing a negative value is the formula (1) shown below.

The equations (2) and (3) shown below are the equations for converting from the XYZ color system to the xy equation degree coordinates of two-dimensional coordinates.

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

[Determination unit 63]
In the present embodiment, the determining unit 63 calculates whether or not the color coordinate value falls within a predetermined range of the color coordinate value, and focuses on the area 209 (see FIG. 6D) having the color coordinate value within the predetermined range. The area 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 the region 209 having color coordinate values characteristically present in the tumor as the predetermined color coordinate range. .. The determination unit 63 sets the area 209 as the attention area 201 where the tumor exists. The predetermined color coordinate range may be set according to the part of the subject 13. The information on the color coordinate range corresponding to the target site may be stored and read as table data in a recording unit (not shown). The determination unit 63 may determine the range 211 including the color existing in a region other than the tumor in the subject 13.

The determining unit 63 may determine, as the attention area 201, an area in which the value of the red pixel is equal to or larger than a predetermined value among the RGB values of the captured image 301. The determining 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 pixel are equal to or more than a predetermined value among the RGB values of the captured image 301.

[Action]
[Illumination operation and imaging operation]
When the first operation unit is operated, 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 travels to the illumination unit 29. The primary light emitted from the light guide member 25 and incident on the illumination unit 29 has a narrow light distribution angle, and the primary light has 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 transmissive member 29b and irradiates the light conversion member 29a.

Part of the primary light is diffused by the diffusing particles. This light is referred to as primary diffused light that is the secondary light SL. The primary diffused light has a diffusion angle different from that of 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 the wavelength of the primary light. This light is referred to as converted light which is the secondary light SL. The converted light is emitted inside the light conversion member 29a without directivity.

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 primary diffused light and the converted light traveling in the opposite directions are reflected by the reflecting member 29c and travel in front of the light converting member 29a. The primary diffused light and the converted light are repeatedly diffused by the diffusing particles and reflected by the reflecting member 29c. Then, as shown in FIGS. 6B and 6C, the primary diffused light and the converted light are emitted from the illumination unit 29 toward the light distribution adjustment illumination unit 90 in a state having a wide light distribution angle as the secondary light SL. .. 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 in the optical element 93 by the relationship described later. In the adjusted state, as shown in FIGS. 6B and 6C, the illumination light IL is emitted from the optical element 31 toward 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. The imaging unit 40 is driven when the second operation unit is operated. The image capturing 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, which is an optical characteristic]
Adjustment of light distribution will be described with reference to FIG. 6E.
Similar to the first embodiment, Steps 1, 2, and 3 are sequentially performed. Next, the extraction unit 61 extracts the color coordinate value and outputs the color coordinate value to the determination unit 63 (Step 21). Then, the determining unit 63 determines the attention area 201 based on the color coordinate values extracted by the extracting unit 61 (Step 22). Step 6 is implemented as in the first embodiment. In Step 6, the setting unit 67 outputs information about the planned illumination area 205 to the control unit 80.

The control unit 80 controls the adjustment mechanism 70 based on this information. Then, the adjustment mechanism 70 adjusts the relative distance between the optical element 93 and the illumination unit 29 based on the control of the control unit 80 (Step 23). Then, Step 8 is executed.

In Steps 22 and 6, for example, when the attention area 201 is larger than the illumination area 203 and the attention area 201 includes the illumination area 203, the planned illumination area 205 is, for example, inside the attention area 201 and in the illumination area 203. Is an area outside of. In this case, the illumination area 203 needs to be enlarged so as to approximate the attention area 201. Therefore, 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 adjusting illumination unit 90 held by the adjusting member 75 moves in association with the adjusting member 75 along the optical axis direction of the primary light with respect to the illumination unit 29. 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 becomes short.

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. Therefore, 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 a wide angle close to the light distribution angle of the secondary light SL, and the light distribution half-value angle of the illumination light IL. Is 120 degrees, for example. 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 be close to the attention area 201, and the planned illumination area 205 is eliminated along with the enlargement. As a result, in Step 8, the planned illumination 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 scheduled illumination 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. Therefore, 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 adjusting illumination unit 90 held by the adjusting member 75 moves in association with the adjusting member 75 along the optical axis direction of the primary light with respect to the illumination unit 29. 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 becomes long.

As shown in FIG. 6C, when the relative distance is long, in the secondary light SL emitted from the illumination unit 29, the component of the secondary light SL formed at a large angle with the optical axis is reflected by the reflecting member 95. It advances and is reflected toward the optical element 93 by the reflecting member 95 so that the angle formed with the optical axis becomes small. Therefore, the amount of adjustment of the light distribution adjustment illumination unit 90 with respect to the secondary light SL is large, and the light distribution angle of the illumination light IL becomes a narrow angle distribution. Therefore, the illumination light IL is emitted from the light distribution adjustment illumination unit 90 as a narrow light distribution. Therefore, the illumination area 203 is reduced so as to be close to the attention area 201, and the unnecessary illumination light IL is eliminated in accordance with the reduction. As a result, in Step 8, the attention area 201, which is the planned illumination 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 values. Therefore, a specific portion, for example, the periphery of the 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 this embodiment, the light distribution characteristic according to 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 the present embodiment, the light amount ratio of the primary light in the illumination regions 203a and 203b is constant, and the illumination region 203 is expanded or reduced according to the light amount of the illumination light IL, not the light distribution adjustment, and the illumination of the illumination region 203 is increased. The position is adjusted by the mechanical structure.

[Constitution]
As shown in FIG. 7A, the endoscope system 10 is elastically deformable by being fixed to the fixing portion 101 while holding the fixing portion 101 fixed to the inner wall of the distal end portion 11 of the insertion portion and the illumination portion 29. And an elastic holding portion 103. One elastic holding unit 103 holds one illuminating 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 hollow portion of the elastic holding portion 103 is engaged with the tip portion of the illumination unit 29. A part of the elastic holding portion 103 is fixed to the fixed portion 101. The fixed portion 101 is arranged outside the elastic holding portion 103.

In this 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 unit 29 is arranged on a concentric circle.

As shown in FIG. 7A and FIG. 7B, the adjustment mechanism 70 includes the inclined portions 110 that are arranged in the same number as the illumination portions 29 and in pairs with the illumination portions 29 and that incline the illumination portions 29 with respect to the central axis of the tip portion 11. Have. In the present embodiment, the adjusting mechanism 70 adjusts the direction, which is the optical characteristic of the illumination light IL, by tilting. The inclined portion 110 is a supply source 111 that supplies an electric current, an electromagnet 113 that is a drive source that is driven by the electric current supplied from the supply source 111, and an acting portion that acts by a magnetic force that is a drive force generated by the electromagnet 113. And a magnetic material 115.

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

The electromagnet 113 is arranged 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 arranged on the elastic holding portion 103 on the opposite side of the fixed portion 101 with the illumination portion 29 interposed therebetween. The magnetic body 115 is arranged laterally of the illumination unit 29 and inside the elastic holding unit 103. When the illuminating section 29 is symmetrically arranged about the image capturing section 41, the magnetic body 115 is disposed between the illuminating section 29 and the image capturing section 41.

As shown in FIGS. 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, which is an optical characteristic]
Adjustment of light distribution will be described with reference to FIG. 7E.
Similar to the first embodiment, Steps 1, 2, and 3 are sequentially performed. Next, the determination unit 63 determines the entire display image 303 as the attention area 201 (Step 31). Step 6 is implemented as in the first embodiment. In Step 6, the setting unit 67 outputs information about 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 light amount of the primary light output from the light source 21 based on the control of the control unit 80 (information regarding the planned illumination area 205). As a result, 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 have to be defined in advance and may be adjusted depending on the situation.

The illumination unit 29 is inclined by the adjustment mechanism 70 with respect to the axial direction of the optical element 31 (Step 33). Specifically, in the adjusting mechanism 70, the supply source 111 supplies a current to the electromagnet 113. When the electromagnet 113 exerts a magnetic force on the magnetic body 115 (the magnetic body 115 is pulled toward the electromagnet 113 or separated from the electromagnet 113), the elastic holding portion 103 holding the illumination unit 29 is fixed to the fixing portion 101 as shown in FIG. 7B. The illuminating section 29 is rotated (curved) about the center of the illuminating section 29 and is inclined with respect to the axial direction of the optical element 31. This changes the emission direction of the illumination light IL. As shown in FIG. 7B, for example, when the electromagnet 113 draws the magnetic body 115, the illumination unit 29 is tilted 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 moves away from the central axis of the imaging unit 41. The tilt angle increases in proportion to the current value.

As the illuminating unit 29 tilts, the illuminating area 203 moves according to the tilt, as shown in FIGS. 7C and 7D. When the electromagnet 113 draws the magnetic substance 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 separate from each other. As a result, the attention area 201, which 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 deviate from the illumination scheduled area 205. For this reason, the illumination area 203 moves so that the area of the planned illumination area 205 is equal to or smaller 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 the display image 303. Therefore, the entire captured image 301 can be illuminated with the illumination light IL.

Since the illumination unit 29 is inclined and the illumination light IL is illuminated on the planned illumination region 205, the illumination light IL can be easily illuminated on a desired portion to be observed.

Since the two or more illuminating units 29 are arranged, it is possible to illuminate the desired region to be observed with the plurality of illumination light IL, and the desired region to be observed can be observed in a bright state.

[Fourth Embodiment]
Hereinafter, with reference to FIGS. 8A, 8B, 8C, and 8D, only points different from the first embodiment will be described. It should be noted that at least one illumination unit 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 adjusting mechanism 70 adjusts the optical characteristic of the illumination light IL by adjusting the light amount ratio of the primary light output from each light source 21.

When the light amount of the primary light is adjusted, the light amount of the 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 central portion of the illumination area 203 is bright and the peripheral portion 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 a part of the illumination area 203b as shown in FIG. 8B. In the captured image 301, the central portion 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 the portion included in the illumination area 203b, the illumination area 203a becomes unnecessary. Therefore, as shown in FIG. 8C, the illumination area 203a is reduced by reducing the light amount of the primary light emitted from the first illumination unit 29. If necessary, the light amount of the primary light emitted from the second illuminating unit 29 is reduced, so that the illumination area 203b of the second illuminating unit 29 is reduced.

[Adjustment of light distribution, which is an optical characteristic]
Adjustment of light distribution will be described with reference to FIG. 8D.
Similar to the first embodiment, Steps 1, 2, 3, 4, 5, 6 are sequentially executed. In Step 6, the setting unit 67 outputs information about 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 light amount of the primary light output from the light source 21 based on the control of the control unit 80 (information regarding the planned illumination area 205). As a result, 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, which is the planned illumination area 205, is illuminated with the illumination light IL (Step 8).

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

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

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

Next, as shown in FIG. 9, the designation unit 120 designates one 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 shown in FIG. 9, the determination unit 63 determines the attention area 201 based on the designated value designated by the designation 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 shown in FIG. The extraction unit 61 extracts the contrast value and outputs the contrast value to the determination unit 63. The determining unit 63 determines the attention area 201 based on the contrast value extracted by the extracting unit 61.
For example, when the designation unit 120 designates a color coordinate value, the designation unit 120 outputs the designation result to the extraction unit 61 as shown in FIG. The extraction unit 61 extracts the color coordinate value and outputs the contrast value to the determination unit 63. The determining unit 63 determines the attention area 201 based on the color coordinate values extracted by the extracting 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 shown 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, as in the first embodiment, Steps 6, 7, and 8 are sequentially performed.

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

[Other]
In the first embodiment, the determining unit 63 determines the attention area 201 based on the contrast value extracted by the extracting 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 determining 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 determining 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 determining unit 63 and the adjusting mechanism 70 in each embodiment does not have to be limited to the above, and can be changed as appropriate.

The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements within a range not departing from the gist of the invention in an implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments.

Claims (17)

An illumination unit that illuminates the subject with illumination light,
An imaging unit for imaging the subject based on the illumination light reflected from the subject;
An attention area determination unit that determines an attention area in the captured image based on the captured image of the subject captured by the imaging unit;
Based on the captured image, an illumination area identifying unit that identifies an illumination area that is an area illuminated by the illumination light,
Based on the inclusion relationship between the determined attention area and the identified illumination area, a target area setting unit that sets a target area illuminated by the illumination light,
An adjustment mechanism that adjusts the optical characteristics of the illumination light so as to approximate the illumination area to the attention area based on the information about the set target area,
An endoscope system comprising: The endoscope system according to claim 1, wherein the adjustment mechanism adjusts the light distribution of the illumination light so that the illumination light is illuminated on the set target area. The captured image is divided into a plurality of regions, further comprising an extraction unit for extracting 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 an area having the contrast value calculated to be higher than the predetermined value as the attention area. The described endoscope system. The captured image is divided into a plurality of regions, further comprising an extraction unit for extracting 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 within the predetermined range as the attention area. The endoscope system according to claim 2. Further comprising a display unit for displaying the captured image,
The endoscope system according to claim 2, wherein the attention area determination unit determines the display image displayed by the display unit as the attention area. The target area setting unit,
In the state where the attention area is larger than the illumination area and the attention area includes the illumination area, the area calculated by subtracting the illumination area from the attention area is set as the target area,
In a state in which the illumination area is larger than the attention area and the illumination area includes the attention area, the attention area is set as the target area,
The endoscope system according to claim 2, wherein the adjustment mechanism adjusts the light distribution of the illumination light so that the area of the target region satisfies a predetermined reference. The endoscope system according to claim 6, wherein the illumination area identifying unit identifies an area having a brightness equal to or higher than a predetermined brightness in the captured image as the illumination area. The illumination unit includes a plurality of illumination units that illuminate the subject with the illumination light, a plurality of illumination units that are arranged in pairs with the plurality of illumination units, and the illumination emitted from the plurality of illumination units. Having a plurality of optical elements through which light passes,
The adjustment mechanism adjusts the relative distances between the plurality of illumination units and the plurality of optical elements in conjunction with each other to adjust the sizes of the plurality of illumination regions of the illumination light emitted from the plurality of illumination units. The endoscope system according to claim 7, wherein the light distribution of the illumination light is adjusted by adjusting. The lighting unit is
A plurality of illumination units that emit the illumination light,
A light distribution adjustment for receiving the illumination light emitted from the plurality of illumination units, adjusting the light distribution characteristic of the received illumination light, and illuminating the subject with the illumination light having the adjusted light distribution characteristic. A lighting unit,
Have
The adjustment mechanism adjusts a relative distance between the plurality of illumination units and the light distribution adjustment illumination unit to adjust sizes of a plurality of illumination regions of the illumination light emitted from the plurality of illumination units. The endoscope system according to claim 7, wherein the light distribution of the illumination light is adjusted thereby. The illumination unit includes a plurality of illumination units that illuminate the subject with the illumination light,
The adjustment mechanism includes an inclined portion that is arranged in pairs with the plurality of illumination portions in the same number as the plurality of illumination portions, and that inclines the plurality of illumination portions.
The adjustment mechanism adjusts the light distribution of the illumination light by inclining the plurality of illumination units and adjusting the position of the illumination area of the illumination light emitted from each of the illumination units along a straight line. The endoscope system according to claim 7. The lighting unit is
A plurality of light sources that emit primary light,
A plurality of illuminating 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 having the converted optical characteristics to the subject as the illumination light. ,
Have
The adjustment mechanism independently adjusts a light amount of the primary light emitted from each of the plurality of light sources, and independently adjusts a size of an illumination area of the illumination light emitted from each of the illumination units. The endoscope system according to claim 7, wherein the light distribution of the illumination light is adjusted by. 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 with the converted optical characteristics as the illumination light to the subject.
The endoscope system according to claim 2, further comprising: 13. The endoscope system according to claim 12, wherein the adjusting mechanism adjusts the light distributions of all the illumination units simultaneously by interlocking with all the illumination units. The endoscope system according to claim 12, wherein the lighting unit has two or more lighting units, and the lighting units of the lighting unit are symmetrically provided with respect to 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 designating unit for designating any one of the contrast value, the color coordinate value, and the display image of the display unit used for determining the attention area;
Further comprising,
The attention area determination unit determines the attention area based on the designated value designated by the designation unit,
When the designation unit designates the contrast value, the attention area determination 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. Determine the area as the area of interest,
When the designation unit designates the color coordinate value, the attention area determination unit calculates whether or not the color coordinate value falls within a predetermined range of the color coordinate value, and the region of interest falls within the predetermined range. An area having color coordinate values is determined as the attention area,
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. The endoscope system according to claim 12, wherein the attention area determination unit determines the attention area based on the area designated by the designation unit from the display image displayed on the display unit. A method of controlling an endoscope system, wherein the control unit of the endoscope system comprises:
An illumination step of controlling an illumination unit to emit illumination light and illuminate the subject with the illumination light, and an imaging step of controlling an imaging unit to image the subject based on the illumination light reflected from the subject When,
An identifying step of controlling an illumination area identifying unit to identify an illumination area, which is an area illuminated by the illumination light, based on a captured image of the captured subject.
A step of controlling the attention area determining unit to determine an attention area in the captured image based on the captured image;
Controlling the target area setting unit, based on the inclusion relationship between the determined attention area and the identified illumination area, a setting step of setting a target area illuminated by the illumination light,
And an adjusting step of adjusting an optical characteristic of the illumination light so as to approximate the illumination area to the attention area based on the set information about the target area. Control method.

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