JP7447249B2 - Test chart, inspection system, and inspection method - Google Patents

Description

The present invention relates to a test chart, an inspection system, and an inspection method used for inspection regarding measurement markers for measuring the size of an object.

BACKGROUND ART In an endoscope system that includes a light source device, an endoscope, and a processor device, information such as the distance to a subject or the size of the subject is acquired. For example, in Patent Document 1, a subject is irradiated with illumination light and measurement light, and a beam irradiation area such as a spot light is caused to appear on the subject by irradiation with beam light. A measurement marker for measuring the size of the object is displayed on the object image in correspondence with the position of the spotlight.

International Publication No. 2018/051680

Since the measurement marker is used to measure the size of a lesion, it is necessary for the measurement marker to accurately display the size of the subject on the subject image. However, the position of the emitting part that emits the measurement light may vary due to differences between endoscopes, and due to such variations in the position of the emitting part, it is difficult for the measurement marker to accurately display the size of the subject. There are things I can't do. Therefore, before using an endoscope that uses a measurement marker, it has been required to perform a check to confirm whether the display of the measurement marker is appropriate.

SUMMARY OF THE INVENTION An object of the present invention is to provide a test chart, an inspection system, and an inspection method that can perform a confirmation inspection to determine whether a measurement marker for measuring the size of an object is properly displayed.

The present invention provides a test chart used for inspection regarding a measurement marker for measuring the size of an object, which includes a chart body provided with an inspection area portion having an inspection area of a specific shape and an inspection reference position; In the inspection image obtained by imaging the chart body irradiated with the measurement light with an endoscope, the inspection area section is configured to adjust the inspection image based on the irradiation position when the irradiation position of the measurement light is aligned with the inspection reference position. It is used to confirm whether the displayed measurement marker is within the inspection area.

The chart body is provided with multiple inspection areas corresponding to the size of the measurement marker, and the confirmation inspection of each inspection area is divided into multiple inspection areas by changing the distance between the measurement light emission position and the chart body. It is preferable that this is done. Preferably, the chart body has a confirmation inspection auxiliary part for assisting confirmation inspection. The specific shape is circular, the plurality of inspection areas are provided concentrically around the inspection reference position, and the confirmation inspection auxiliary part has a plurality of inspection areas that extend radially from the inspection reference position and intersect with the inspection area. radial lines are preferable. Preferably, the angular intervals of the radial lines are equal angular intervals. Preferably, the radial lines are symmetrical.

The test chart is provided with a plurality of inspection areas corresponding to the size of the measurement marker, and the confirmation inspection of each inspection area is carried out by keeping the distance between the measurement light emission position and the chart body constant. Preferably, this is done twice. Preferably, the specific shape is circular, and the plurality of inspection areas share one specific point in each inspection area as an inspection reference position.

Preferably, the plurality of inspection areas have different saturations. It is preferable that the hue of the measurement light when the chart body is irradiated is the same as the hue of the measurement light when the subject is irradiated. It is preferable that the inspection area and the area other than the inspection area of the chart body have the same hue.

It is preferable that the width of the inspection area has an error range corresponding to the size of the measurement marker. It is preferable that the width of the inspection area increases as the size of the measurement marker increases. It is preferable to have a chart identifier that can identify the type of the chart body.

The inspection system of the present invention displays a test image obtained by imaging a test chart having a chart body provided with an inspection reference position and the chart body irradiated with measurement light from an endoscope using an endoscope. It includes a display, a moving mechanism section that holds the endoscope in a state where the distal end of the endoscope faces the test chart, and movably holds the test chart, and the moving mechanism section is configured to move the measurement light. By changing at least either the distance between the emission position and the chart body or the measurement light irradiation position on the chart body, the measurement light irradiation position is aligned with the inspection reference position in the inspection image.

The chart body has an inspection area section having an inspection area of a specific shape, and the inspection area section determines the irradiation position of the measurement light in an inspection image obtained by imaging the chart body irradiated with the measurement light with an endoscope. It is preferable to use the measurement marker to confirm whether or not the measurement marker displayed on the inspection image based on the irradiation position is within the inspection area when the inspection reference position is aligned with the inspection reference position.

The test chart has multiple inspection areas corresponding to the size of the measurement marker, and the moving mechanism changes the distance between the measurement light emission position and the chart body for each confirmation inspection of each inspection area. Preferably, the display displays a measurement marker corresponding to the distance each time the distance is changed, thereby dividing each inspection area into a plurality of confirmation inspections.

The test chart is provided with multiple inspection areas corresponding to the size of the measurement marker, the moving mechanism maintains a constant distance between the measurement light emission position and the chart body, and the display has multiple inspection areas that correspond to the size of the measurement marker. It is preferable to display all the measurement markers corresponding to the inspection area to perform a confirmation inspection on all the inspection areas at one time.

Preferably, the measurement light is spot light. Preferably, the measurement light is a line-shaped measurement light. Preferably, the measurement light is patterned measurement light. Preferably, the measurement light is three-dimensional plane light.

The present invention provides an inspection method using a test chart having a chart body provided with an inspection reference position, including a step of imaging the chart body irradiated with measurement light from an endoscope to obtain an inspection image. , displaying the inspection image on a display, and changing at least one of the distance between the measurement light emission position and the chart body, or the measurement light irradiation position on the chart body. and adjusting the irradiation position to the inspection reference position.

According to the present invention, it is possible to perform a confirmation test to determine whether a measurement marker for measuring the size of a subject is displayed appropriately.

FIG. 1 is an external view of an endoscope system. FIG. 3 is a plan view showing the distal end of the endoscope. FIG. 2 is a block diagram showing the functions of the endoscope system. (A) is an explanatory diagram showing a subject image with the digital zoom function OFF, and (B) is an explanatory diagram showing a subject image with the digital zoom function ON. FIG. 3 is a block diagram showing a beam light emitting section. FIG. 3 is an explanatory diagram showing a spot SP formed on a subject by measurement light. FIG. 3 is an explanatory diagram showing the relationship between the distal end of the endoscope and a near end Px, near the center Py, and a far end Pz within the observation distance range Rx. FIG. 2 is a block diagram showing the functions of a signal processing section. FIG. 7 is an image diagram showing a spot and a first measurement marker when the observation distance is the near end Px. FIG. 7 is an image diagram showing a spot and a first measurement marker when the observation distance is near the center Py. It is an image diagram showing the spot and the first measurement marker when the observation distance is the far end Pz. FIG. 3 is an explanatory diagram showing first measurement markers of a cross shape, a scaled cross shape, a distorted cross shape, a circle and a cross shape, and a measurement point group type. FIG. 3 is an image diagram showing three concentric markers each having the same color. FIG. 3 is an image diagram showing three concentric markers of different colors. FIG. 7 is an image diagram showing markers in the shape of distorted concentric circles. FIG. 3 is an explanatory diagram showing a light emission pattern in which spot light is intermittently irradiated. It is an image diagram showing intersecting lines and scales. FIG. 3 is an explanatory diagram showing a light emission pattern in which line-shaped measurement light is intermittently irradiated. It is an explanatory view showing striped pattern light ZPL. FIG. 3 is an explanatory diagram showing a light emission pattern of striped pattern light ZPL of phase X, phase Y, and phase Z. It is an explanatory view showing measurement light LPL of a lattice pattern. FIG. 3 is an explanatory diagram showing a light emission pattern in which measurement light in a grid pattern is intermittently irradiated. FIG. 3 is an explanatory diagram showing a three-dimensional plane light TPL. FIG. 3 is an explanatory diagram showing a light emission pattern in which three-dimensional plane light is intermittently irradiated. FIG. 2 is a block diagram showing the functions of the inspection system. FIG. 7 is a plan view showing a test chart used when performing confirmation tests on a plurality of measurement markers in a plurality of times. FIG. 3 is an image diagram showing an inspection image in which measurement markers are displayed based on the irradiation position of measurement light. FIG. 3 is a front view showing the moving mechanism section. It is an image figure which shows the test|inspection image when the measurement marker Mp is in the test|inspection area. It is an image diagram showing an inspection image when a part of the measurement marker Mp protrudes from the inspection area. It is an image figure which shows the test|inspection image when the measurement marker Mq is in the test|inspection area. It is an image figure which shows the test|inspection image when the measurement marker Mr is in the test|inspection area. It is a top view which shows the test chart used when performing the confirmation test|inspection of several measurement markers at once. FIG. 7 is an image diagram showing an inspection image when all measurement markers Mp, Mq, and Mr are in the corresponding inspection area when a confirmation inspection of a plurality of measurement markers is performed at one time. FIG. 7 is an image diagram showing an inspection image when one measurement marker Mp protrudes from a corresponding inspection area when a confirmation inspection of a plurality of measurement markers is performed at one time. FIG. 2 is a plan view showing a test chart provided with a diamond-shaped test area. FIG. 2 is a plan view showing a test chart provided with a rectangular inspection area. It is a sectional view showing the layered structure of the chart body of the test chart. FIG. 7 is a plan view showing a test chart when linear measurement light is used. FIG. 3 is a plan view showing a test chart when patterned measurement light is used. 3 is a flowchart showing a series of steps in a calibration mode.

As shown in FIG. 1, the endoscope system 10 includes an endoscope 12, a light source device 14, a processor device 16, a display 18, and a user interface 20. The endoscope 12 includes an insertion section 12a that is inserted into a subject, an operation section 12b provided at the proximal end of the insertion section 12a, and a universal cable 12c. The universal cable 12c includes a light guide 28 (see FIG. 3) that guides illumination light emitted by the light source device 14, a control line that transmits control signals used to control the endoscope 12, and a control line that transmits an image of an observation target. This is a cable that integrates a signal line for transmitting the image signal obtained by the process, a power line for supplying power to each part of the endoscope 12, and the like. A connector 29 connected to the light source device 14 is provided at the tip of the universal cable 12c.

The light source device 14 generates illumination light using, for example, a semiconductor light source such as an LED (Light Emitting Diode) or an LD (Laser Diode), a xenon lamp, a halogen lamp, or the like. When the connector 29 is connected to the light source device 14, illumination light enters the light guide 28 (see FIG. 3) of the connector 29, and is irradiated onto the observation target from the tip of the insertion portion 12a.

Further, the light source device 14 is electrically connected to the processor device 16, and the connector 29 of the endoscope 12 is connected to the processor device 16 via the light source device 14. Transmission and reception of control signals, image signals, and the like between the light source device 14 and the connector 29 is wireless communication. Therefore, the light source device 14 transmits control signals and the like wirelessly transmitted and received with the connector 29 to the processor device 16. Furthermore, the light source device 14 supplies power for driving the endoscope 12 to the connector 29, and this power is also supplied wirelessly.

The processor device 16 controls the amount and timing of illumination light emitted by the light source device 14, and each part of the endoscope 12, and creates an endoscope image using an image signal obtained by imaging an observation target irradiated with the illumination light. generate. Processor device 16 is also electrically connected to display 18 and user interface 20 . The display 18 displays the endoscopic image generated by the processor device 16, information regarding the endoscopic image, and the like. The user interface 20 has a function of accepting input operations such as function settings.

The endoscope 12 has a normal observation mode, a special light observation mode, a length measurement mode, and a calibration mode. It is switched by switch 13a. The normal observation mode is a mode in which the observation target is illuminated with illumination light. The special light observation mode is a mode in which the observation target is illuminated with special light different from illumination light. In the length measurement mode, the observation target is illuminated with illumination light and measurement light, and measurement markers used to measure the size of the observation target are displayed on the subject image obtained by imaging the observation target. The calibration mode is a mode for checking whether the display of measurement markers is appropriate using a test chart. Details of the calibration mode will be described later. Note that the illumination light is light that is used to provide brightness to the entire observation object and to observe the entire observation object. Special light is light used to emphasize a specific region of the observation target, such as a surface blood vessel. The measurement light is light used to display measurement markers.

Further, the operation unit 12b of the endoscope 12 is provided with a freeze switch 13b for operating a still image acquisition instruction for instructing the acquisition of a still image of a subject image. When the user operates the freeze switch 13b, the screen of the display 18 freezes and an alert sound (for example, "beep") indicating that a still image is to be acquired is emitted. Then, still images of the subject image obtained before and after the operation timing of the freeze switch 13b are stored in the still image storage section 42 (see FIG. 3) in the processor device 16. Note that the still image storage section 42 is a storage section such as a hard disk, a USB (Universal Serial Bus) memory, or a nonvolatile memory. If the processor device 16 is connectable to a network, instead of or in addition to the still image storage unit 42, the still image of the subject image is stored in a still image storage server (not shown) connected to the network. It's okay. In addition, if the still image storage section 42 is a non-volatile memory, after the still image is temporarily stored in the still image storage section 42, the still image is stored in a USB memory, a CF (Compact Flash) card, an image storage server on a network, etc. may be transferred.

Note that the still image acquisition instruction may be issued using an operating device other than the freeze switch 13b. For example, a foot pedal may be connected to the processor device 16, and the still image acquisition instruction may be issued when the user operates the foot pedal (not shown) with his/her foot. Mode switching may be performed using a foot pedal. Further, a gesture recognition unit (not shown) that recognizes a user's gesture is connected to the processor device 16, and when the gesture recognition unit recognizes a specific gesture performed by the user, it issues a still image acquisition instruction. You can also do this. Mode switching may also be performed using the gesture recognition unit.

In addition, a line-of-sight input unit (not shown) provided near the display 18 is connected to the processor device 16, and the line-of-sight input unit recognizes that the user's line of sight has entered a predetermined area of the display 18 for a certain period of time or more. In this case, a still image acquisition instruction may be issued. Further, a voice recognition section (not shown) may be connected to the processor device 16, and when the voice recognition section recognizes a specific voice uttered by the user, a still image acquisition instruction may be issued. The mode switching may also be performed using the voice recognition section. Further, an operation panel (not shown) such as a touch panel may be connected to the processor device 16, and a still image acquisition instruction may be issued when the user performs a specific operation on the operation panel. Mode switching may also be performed using an operation panel.

As shown in FIG. 2, the distal end 12d of the endoscope 12 is approximately circular, and includes an imaging optical system 21 that receives light from a subject and an illumination optical system that irradiates illumination light to the subject. 22, a beam light emitting unit 23 that emits measurement light to the subject, an opening 24 for protruding the treatment tool toward the subject, and an air/water supply nozzle 25 for supplying air and water. It is provided.

The optical axis Ax of the imaging optical system 21 extends in a direction perpendicular to the plane of the paper. The first vertical direction D1 is perpendicular to the optical axis Ax, and the second horizontal direction D2 is perpendicular to the optical axis Ax and the first direction D1. The imaging optical system 21 and the beam light emitting section 23 are provided at different positions on the tip portion 12d, and are arranged along the first direction D1.

As shown in FIG. 3, the light source device 14 includes a light source section 26 and a light source control section 27. The light source section 26 generates illumination light or special light for illuminating a subject. Illumination light or special light emitted from the light source section 26 is incident on the light guide 28, passes through the illumination lens 22a, and is irradiated onto the subject. The light source unit 26 may be a light source for illumination light, such as a white light source that emits white light, or a plurality of light sources that include a white light source and a light source that emits light of other colors (for example, a blue light source that emits blue light). is used. Further, as the light source section 26, a light source that emits broadband light including blue narrowband light for emphasizing surface information such as superficial blood vessels is used as a special light source. The light source control section 27 is connected to the system control section 41 of the processor device 16. Note that the illumination light may be white mixed color light that is a combination of blue light, green light, and red light. In this case, it is preferable to optically design the illumination optical system 22 so that the irradiation range of the green light is larger than the irradiation range of the red light.

The light source control section 27 controls the light source section 26 based on instructions from the system control section 41. The system control section 41 not only instructs the light source control section 27 regarding light source control, but also controls the light source 23a of the beam light emitting section 23 (see FIG. 5). In the case of the normal observation mode, the system control unit 41 performs control to turn on the illumination light and turn off the measurement light. In the special light observation mode, control is performed to turn on the special light and turn off the measurement light. In the case of length measurement mode, the system control unit 41 performs control to turn on the illumination light and turn on the measurement light. In the case of calibration mode, the system control unit 41 controls to turn off the illumination light and turn on the measurement light.

The illumination optical system 22 has an illumination lens 22a, and light from the light guide 28 is irradiated onto the observation target via the illumination lens 22a. The imaging optical system 21 includes an objective lens 21a, a zoom lens 21b, and an image sensor 32. Reflected light from the observation target enters the image sensor 32 via the objective lens 21a and the zoom lens 21b. As a result, a reflected image of the observation target is formed on the image sensor 32.

The zoom lens 21b has an optical zoom function of enlarging or reducing a subject by moving between a telephoto end and a wide end. The optical zoom function can be turned on and off using the zoom operation section 13c (see Fig. 1) provided on the operation section 12b of the endoscope. By operating 13c, the subject is enlarged or reduced at a specific enlargement rate.

The image sensor 32 is a color image sensor that captures a reflected image of the subject and outputs an image signal. The image sensor 32 is preferably a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, or the like. The image sensor 32 used in the present invention is a color image sensor for obtaining a red image, a green image, and a red image in three colors: R (red), G (green), and B (blue). The red image is an image output from a red pixel provided with a red color filter in the image sensor 32. The green image is an image output from a green pixel provided with a green color filter in the image sensor 32. The blue image is an image output from a blue pixel provided with a blue color filter in the image sensor 32. The imaging device 32 is controlled by an imaging control section 33.

The image signal output from the image sensor 32 is transmitted to the CDS/AGC circuit 34. The CDS/AGC circuit 34 performs correlated double sampling (CDS) and automatic gain control (AGC) on the image signal, which is an analog signal. The image signal that has passed through the CDS/AGC circuit 34 is converted into a digital image signal by an A/D converter (A/D (Analog/Digital) converter) 35. The A/D converted digital image signal is input to a communication I/F (Interface) 37 of the light source device 14 via a communication I/F (Interface) 36 .

The processor device 16 includes a receiving section 38 connected to a communication I/F (Interface) 37 of the light source device 14, a signal processing section 39, a display control section 40, and a system control section 41. The communication I/F receives the image signal transmitted from the communication I/F 37 and transmits it to the signal processing unit 39 . The signal processing section 39 has a built-in memory that temporarily stores the image signal received from the receiving section 38, and processes the image signal group, which is a collection of image signals stored in the memory, to generate a subject image. Note that the receiving section 38 may directly send control signals related to the light source control section 27 to the system control section 41. Furthermore, in the processor device 16, the processing units related to the length measurement mode (for example, the first signal processing unit 50 and the second signal processing unit 52) are provided with a length measurement processor (not shown) that is separate from the processor device 16. (No) may be provided. In this case, the length measurement processor and the processor device 16 are kept in a state where they can communicate with each other so that images or various information can be sent and received.

In the signal processing unit 39, when the normal observation mode is set, the blue image of the subject image is displayed on the B channel of the display 18, the green image of the subject image is displayed on the G channel of the display 18, and the red image of the subject image is displayed on the G channel of the display 18. A color object image is displayed on the display 18 by performing signal assignment processing to assign each signal to the R channel of the display 18. In the length measurement mode, the same signal assignment processing as in the normal observation mode is performed. On the other hand, in the signal processing unit 39, when the special light observation mode is set, the red image of the subject image is not used for display on the display 18, and the blue image of the subject image is displayed on the B channel and G of the display 18. By assigning the green image of the subject image to the R channel of the display 18, a pseudo-color subject image is displayed on the display 18.

As a zoom function, when the digital zoom function is set to ON by the user interface 20, the signal processing unit 39 enlarges or reduces the subject at a specific magnification by cutting out a part of the subject image and enlarging or reducing it. to shrink. FIG. 4(A) shows a subject image with the digital zoom function OFF, and FIG. 4(B) shows an image of the subject with the digital zoom function ON, which is a cropped and enlarged image of the center part of the subject image in FIG. 4(A). The image is shown. Note that when the digital zoom function is OFF, the subject is not enlarged or reduced by cutting out the subject image.

Note that when the signal processing unit 39 is set to the length measurement mode, the signal processing unit 39 performs structure enhancement processing on the subject image to emphasize structures such as blood vessels, and distinguishes between normal parts and diseased parts of the observation target. Color difference enhancement processing that expands the color difference may also be performed.

The display control unit 40 displays the subject image generated by the signal processing unit 39 on the display 18. The system control unit 41 controls the imaging device 32 via the imaging control unit 33 provided in the endoscope 12. The imaging control unit 33 also controls the CDS/AGC 34 and the A/D 35 in accordance with the control of the imaging device 32.

As shown in FIG. 5, the beam light emitting section 23 emits measurement light obliquely with respect to the optical axis Ax of the imaging optical system 21. The beam light emitting section 23 includes a light source 23a, a diffractive optical element DOE23b (Diffractive Optical Element), a prism 23c, and a light emitting section 23d. The light source 23a emits colored light (specifically visible light) that can be detected by the pixels of the image sensor 32, and is a light emitting element such as a laser light source LD (Laser Diode) or an LED (Light Emitting Diode). , and a condensing lens that condenses the light emitted from the light emitting element. Note that the light source 23a is provided on a scope electric board (not shown). The scope electric board is provided at the distal end portion 12d of the endoscope, receives power from the light source device 14 or the processor device 16, and supplies power to the light source 23a.

In this embodiment, the wavelength of the light emitted by the light source 23a is, for example, red (beam light color) laser light with a wavelength of 600 nm or more and 660 nm or less, but light in other wavelength bands, for example, 495 nm or more and 570 nm or less. green light may also be used. The light source 23a is controlled by the system control section 41 and emits light based on instructions from the system control section 41. The DOE 23b converts the light emitted from the light source into measurement light for obtaining measurement information. Note that the light intensity of the measurement light is adjusted based on the viewpoint of protecting the human body, eyes, and internal organs, and the light intensity may be adjusted to a level that sufficiently causes overexposure (pixel saturation) in the observation range of the endoscope 12. preferable.

The prism 23c is an optical member for changing the traveling direction of the measurement light after conversion by the DOE 23b. The prism 23c changes the traveling direction of the measurement light so that it intersects the field of view of the imaging optical system 21 including the objective lens 21a. Details of the traveling direction of the measurement light will also be described later. The measurement light Lm emitted from the prism 23c passes through an emitting section 23d formed of an optical member and is irradiated onto the subject.

By irradiating the subject with the measurement light, a spot SP is formed as a beam irradiation area on the subject, as shown in FIG. The position of this spot SP is characterized by the irradiation position detection section 58 (see FIG. 8), and a measurement marker representing the size of the subject is set according to the position of the spot SP. The set measurement marker is displayed on the subject image. Note that, as described later, the measurement marker includes multiple types such as a first measurement marker and a second measurement marker, and it is difficult to determine which type of measurement marker to display on the subject image. can be selected according to the user's instructions. For example, the user interface 20 is used for the user's instructions.

In addition, instead of configuring the emission part 23d with an optical member, it may be a measurement auxiliary slit formed in the distal end part 12d of the endoscope. Further, when the emission section 23d is formed of an optical member, it is preferable to apply an anti-reflection coating (AR (Anti-Reflection) coat) (anti-reflection section). The reason for providing the anti-reflection coating in this way is that when the measurement light is reflected without passing through the emission part 23d and the proportion of the measurement light irradiated to the subject decreases, the irradiation position detection part 58, which will be described later, This is because it becomes difficult to recognize the position of the spot SP formed on the subject.

Note that the beam light emitting section 23 may be of any type as long as it can emit the measurement light toward the field of view of the imaging optical system 21. For example, the light source 23a may be provided in a light source device, and the light emitted from the light source 23a may be guided to the DOE 23b by an optical fiber. Moreover, by installing the light source 23a and the DOE 23b obliquely with respect to the optical axis Ax of the imaging optical system 21 without using the prism 23c, the measurement light Lm is emitted in a direction that crosses the field of view of the imaging optical system 21. It is also possible to have a configuration in which the

Regarding the traveling direction of the measurement light, the measurement light is emitted in a state where the optical axis Lm of the measurement light intersects the optical axis Ax of the imaging optical system 21, as shown in FIG. Assuming that observation is possible in the observation distance range Rx, at the near end Px, near the center Py, and far end Pz of the range Rx, the measurement light Lm in the imaging range (indicated by arrows Qx, Qy, and Qz) at each point It can be seen that the positions of the spots SP formed on the subject (the points where the arrows Qx, Qy, and Qz intersect with the optical axis Ax) are different. Note that the photographing angle of view of the imaging optical system 21 is expressed within the area sandwiched by the two solid lines 101a, and the measurement is performed in the central area (the area sandwiched between the two dotted lines 101b) with less aberration among this photographing angle of view. I have to.

As described above, by emitting the measurement light Lm in a state where the optical axis Lm of the measurement light intersects the optical axis Ax, it is possible to measure the size of the object from the movement of the spot position in response to changes in the observation distance. can. Then, by capturing an image of the subject illuminated with the measurement light using the image sensor 32, a subject image including the spot SP is obtained. In the subject image, the position of the spot SP varies depending on the relationship between the optical axis Ax of the imaging optical system 21 and the optical axis Lm of the measurement light Lm, and the observation distance. For example, the number of pixels indicating a distance of 5 mm increases, and the longer the observation distance, the fewer pixels there are.

As shown in FIG. 8, the signal processing unit 39 of the processor device 16 controls whether or not the length measurement mode can be executed, and detects the position of the spot SP in the subject image in a state where the length measurement mode is permitted to be executed. and a second signal processing section 52 that sets a measurement marker according to the position of the spot SP. Note that when the normal observation mode is set, a subject image of a subject illuminated by illumination light is input to the signal processing unit 39. When the special light observation mode is set, a subject image of a subject illuminated by special light is input. When set to length measurement mode, a subject image of a subject illuminated by illumination light and measurement light is input. When set to calibration mode, an inspection image of a chart on which a calibration pattern is formed is input, but the illumination light at that time changes depending on the progress of the calibration, such as measurement light and illumination. The light can be switched arbitrarily.

The first signal processing section 50 includes an irradiation position detection section 58 that detects the irradiation position of the spot SP from the subject image or the inspection image. The irradiation position detection unit 58 detects the irradiation position of the spot SP from the subject image in a state where execution of the length measurement mode is permitted. Specifically, the irradiation position detection unit 58 calculates the coordinates of the spot SP from the subject image in real time, and determines the irradiation position of the spot SP from the calculated coordinates. In order for the irradiation position detection unit 58 to detect the irradiation position of the spot SP, it is absolutely necessary that the subject image includes a beam color light image based on the color of the measurement light. As a method for detecting the irradiation position, it is preferable to obtain the coordinates of the center of gravity of the spot SP in the subject image.

The second signal processing unit 52 sets a first measurement marker as a measurement marker for measuring the size of the subject based on the irradiation position of the spot SP, and displays the first measurement marker on the display 18. Set the marker display position to be displayed. The second signal processing unit 52 refers to a marker table 62 that stores measurement marker images whose display modes differ depending on the irradiation position of the spot SP and the marker display position in association with the irradiation position of the spot, and determines the irradiation position. Set the measurement marker image corresponding to.

The measurement marker image differs in size or shape, for example, depending on the irradiation position of the spot SP and the marker display position. The display of the measurement marker image will be described later. Furthermore, the saved contents of the marker table 62 are maintained even when the power of the processor device 16 is turned off. Note that the marker table 62 stores measurement marker images and irradiation positions in association with each other; It may be stored in association with the marker image.

When displaying the measurement image in which the measurement marker is superimposed on the subject image on the display 18, the display control unit 40 controls the measurement marker so that the display mode differs depending on the irradiation position of the spot SP and the marker display position. conduct. Specifically, the display control unit 40 displays on the display 18 a measurement image on which the first measurement marker is superimposed, centering on the spot SP. As the first measurement marker, for example, a circular measurement marker is used. In this case, as shown in FIG. 9, when the observation distance is close to the near end Px, the actual size is 5 mm (horizontal and vertical direction of the subject image) to match the center of the spot SP1 formed on the subject's tumor tm1. A marker M1 indicating the direction) is displayed. Note that when the measurement marker is displayed on the display 18, the observation distance may also be displayed on the display 18.

Since the marker display position of the marker M1 is located at the periphery of the subject image that is affected by distortion caused by the imaging optical system 21, the marker M1 has an elliptical shape in accordance with the effects of distortion and the like. Since the marker M1 described above almost coincides with the range of the tumor tm1, the tumor tm1 can be measured to be approximately 5 mm. Note that for the subject image, only the first measurement marker may be displayed without displaying the spot.

In addition, as shown in Fig. 10, when the observation distance is close to the center Py, the actual size is 5 mm (horizontal and vertical directions of the subject image) to match the center of the spot SP2 formed on the subject's tumor tm2. The marker M2 shown is displayed. The marker display position of the marker M2 is located at the center of the subject image, which is not easily affected by distortion due to the imaging optical system 21, so the marker M2 has a circular shape without being affected by distortion etc. .

Further, as shown in FIG. 11, a marker M3 indicating an actual size of 5 mm (in the horizontal and vertical directions of the subject image) is displayed in alignment with the center of the spot SP3 formed on the tumor tm3 of the subject. Since the marker display position of the marker M3 is located at the periphery of the subject image that is affected by distortion caused by the imaging optical system 21, the marker M1 has an elliptical shape in accordance with the effects of distortion and the like. As shown in FIGS. 9 to 11 above, as the observation distance increases, the size of the first measurement marker corresponding to the same actual size of 5 mm becomes smaller. Further, depending on the marker display position, the shape of the first measurement marker also differs depending on the influence of distortion caused by the imaging optical system 21.

In addition, in FIGS. 9 to 11, the center of the spot SP and the center of the marker are shown aligned, but if there is no problem with measurement accuracy, the first measurement marker may be placed at a position away from the spot SP. may be displayed. However, in this case as well, it is preferable to display the first measurement marker near the spot. Further, instead of displaying the first measurement marker in a deformed manner, the distortion aberration of the subject image may be corrected and the first measurement marker in an undeformed state may be displayed on the corrected subject image. .

In addition, in FIGS. 9 to 11, the first measurement marker corresponding to the actual size of the subject is 5 mm, but the actual size of the subject can be set to any value (for example, 2 mm) depending on the observation target and observation purpose. , 3mm, 10mm, etc.). Further, in FIGS. 9 to 11, the first measurement marker has a substantially circular shape, but as shown in FIG. 12, it may have a cross shape in which a vertical line and a horizontal line intersect. Moreover, it may be a cross shape with a scale in which a scale Mx is attached to at least one of the vertical line and the horizontal line of the cross shape. Further, the first measurement marker may be in the shape of a distorted cross with at least one of vertical lines and horizontal lines inclined. Further, the first measurement marker may be a circle or a cross, which is a combination of a cross and a circle. Alternatively, the first measurement marker may be of a measurement point cloud type that combines a plurality of measurement points EP corresponding to the actual size from the spot. Further, the number of first measurement markers may be one or more, and the color of the first measurement markers may be changed depending on the actual size.

As the first measurement marker, as shown in FIG. 13, three concentric markers M4A, M4B, and M4C (diameters of 2 mm, 5 mm, and 10 mm, respectively) with different sizes were placed on the tumor tm4. It may be displayed on the subject image centering on the spot SP4 formed in . These three concentric markers display a plurality of markers, which saves the effort of switching, and also enables measurement even when the object has a nonlinear shape. Note that when displaying multiple concentric markers around a spot, instead of specifying the size and color for each marker, you can prepare multiple combinations of conditions in advance and select from among the combinations. You can also do this.

In Figure 13, all three concentric markers are displayed in the same color (black), but when multiple concentric markers are displayed, they can also be displayed as multiple colored concentric markers with different colors depending on the marker. good. As shown in FIG. 14, the marker M5A is indicated by a dotted line representing red, the marker M5B is indicated by a solid line representing blue, and the marker M5C is indicated by a dashed line representing white. By changing the color of the marker in this way, identifiability is improved and measurement can be easily performed.

Further, as the first measurement marker, in addition to a plurality of concentric markers, as shown in FIG. 15, a plurality of distorted concentric markers in which each concentric circle is distorted may be used. In this case, distorted concentric markers M6A, M6B, and M6C are displayed on the subject image centered on the spot SP5 formed on the tumor tm5.

In addition, in the length measurement mode, the illumination light and spot light (measurement light) are constantly illuminated on the subject, but as shown in Figure 16, while the illumination light is always on and illuminated on the subject, the spot light The spotlight may be intermittently irradiated onto the subject by repeating turning on and turning off (or dimming) the light every frame (or every few frames). In this case, the position of the spotlight is detected and the display setting of the measurement marker is performed in the frame in which the spotlight is turned on. Preferably, the measurement marker for which display settings have been made is displayed in a superimposed manner on an image obtained in a frame in which only illumination light is irradiated.

Note that although the measurement light is the light that is formed as a spot when irradiated onto the subject, other light may be used. For example, linear measurement light may be used that, when irradiated onto the subject, forms an intersecting line 80 on the subject, as shown in FIG. By irradiating the object with the linear measurement light, an intersecting line 80, which is a linear irradiation area, is formed on the object. In this case, as the measurement marker, a second measurement marker is generated, which is composed of the intersection line 80 and a scale 82 on the intersection line 80 that is an index of the size of the subject (for example, polyp P). When using linear measurement light, the irradiation position detection unit 58 detects the position of the intersecting line 80 (the irradiation position of the measurement light). The lower the intersection line 80 is located, the closer the observation distance is, and the higher the intersection line 80 is located, the farther the observation distance is. Therefore, the lower the intersection line 80 is located, the larger the interval between the scales 82 becomes, and the higher the intersection line 80 is located, the smaller the interval between the scales 82 becomes.

When using a line-shaped measurement light as the measurement light, the illumination light and the line-shaped measurement light may be constantly irradiated onto the subject during length measurement mode, and as shown in FIG. While constantly illuminating the subject, the line-shaped measurement light is intermittently illuminated on the subject by repeating turning on and off (or dimming) every frame (or every few frames). You may. In this case, in the frame in which the linear measurement light is turned on, the position of the linear measurement light is detected and the display setting of the measurement marker is performed. Preferably, the measurement marker for which display settings have been made is displayed in a superimposed manner on an image obtained in a frame in which only illumination light is irradiated.

As for the measurement light, striped pattern light ZPL that forms a striped pattern of light on the subject as shown in FIG. 19 when irradiated onto the subject may be used (for example, (Refer to Publication No. 2016-198304). The striped pattern light ZPL is obtained by irradiating a variable transmittance liquid crystal shutter (not shown) with a specific laser beam. It is formed from two different patterns of vertical stripes that do not transmit (non-transparent areas) and that are periodically repeated in the horizontal direction. When using striped pattern light as measurement light, the period of the striped pattern light changes depending on the distance to the subject, so the period or phase of the striped pattern light is shifted using a liquid crystal shutter and irradiated multiple times. The three-dimensional shape of an object is measured based on a plurality of images obtained by shifting the period or phase.

For example, a striped pattern light of phase X, a striped pattern light of phase Y, and a striped pattern light of phase Z are alternately irradiated onto the subject. The striped pattern light of phases X, Y, and Z has the vertical striped pattern shifted in phase by 120° (2π/3). In this case, the three-dimensional shape of the subject is measured using three types of images obtained based on each striped pattern of light. For example, as shown in FIG. 20, the striped pattern light of phase X, the striped pattern light of phase Y, and the striped pattern light of phase Z are switched in units of one frame (or in units of several frames). It is preferable to irradiate the subject. Note that it is preferable that the illumination light is always irradiated onto the subject.

Regarding the measurement light, measurement light LPL with a grid pattern that is formed as a grid pattern as shown in FIG. 21 when irradiated onto the subject may be used (for example, Japanese Patent Application Laid-Open No. 2017-217215 (see publication). In this case, since the three-dimensional shape of the subject is measured based on the deformed state of the grid pattern when the subject is irradiated with the measurement light LPL in the grid pattern, it is required to accurately detect the grid pattern. Therefore, the measurement light LPL of the grid pattern is not completely grid-shaped, but is slightly deformed from the grid pattern, such as by making it wavy, so as to improve the detection accuracy of the grid pattern. Further, the grid pattern is provided with an S code indicating that the end points of the left and right horizontal line segments are continuous. When detecting a grid pattern, not only the pattern but also the S code is detected to improve pattern detection accuracy. Note that the grid pattern may be a pattern in which vertical lines and horizontal lines are regularly arranged, or a pattern in which a plurality of spots are arranged vertically and horizontally in a grid pattern.

When using the measurement light LPL with a grid pattern as the measurement light, the illumination light and the measurement light LPL with the grid pattern may be constantly irradiated onto the subject during the length measurement mode, or as shown in FIG. While the illumination light is constantly irradiated onto the subject, the grid pattern measurement light LPL is repeatedly turned on and off (or dimmed) every frame (or every few frames). LPL may be intermittently irradiated onto the subject. In this case, the three-dimensional shape is measured based on the grid pattern measurement light LPL in a frame in which the grid pattern measurement light LPL is turned on. Preferably, the measurement results of the three-dimensional shape are displayed superimposed on the image obtained in the frame in which only the illumination light is irradiated.

Note that as for the measurement light, as shown in FIG. 23, three-dimensional planar light TPL represented by mesh lines on the subject image may be used (for example, see Japanese Patent Publication No. 2017-508529). In this case, the tip 12d is moved so that the three-dimensional plane light TPL matches the object to be measured. Then, when the three-dimensional plane light TPL intersects the object to be measured, the distance of the intersection curve CC between the three-dimensional parallel light TPL and the subject is calculated by processing based on manual operation of a user interface or the like or by automatic processing.

When using the three-dimensional plane light TPL as the measurement light, the illumination light and the three-dimensional plane light TPL may be constantly irradiated onto the subject during the length measurement mode, and as shown in FIG. While the subject is always illuminated, the three-dimensional plane light TPL is intermittently illuminated on the subject by repeating turning on and off (or dimming) every frame (or every few frames). You may.

The details of the calibration mode will be explained. In addition to the endoscope system 10, the calibration mode is executed in cooperation with the inspection system 100 connected to the processor device 16 of the endoscope system 10. When the mode changeover switch 13a is operated to switch to the calibration mode, the endoscope 12 emits measurement light. In the calibration mode, measurement light is irradiated onto the test chart (see FIG. 26) to perform a confirmation test to determine whether or not the display of measurement markers is appropriate.

As shown in FIG. 25, the inspection system 100 includes a test chart 102, a display 18, and a moving mechanism section 104. Note that the display 18 shares the display used in the endoscope system 10, but a separate display for accuracy inspection may be provided.

As shown in FIG. 26, the test chart 102 has a chart body 105, and the chart body 105 includes an inspection area section 106 having an inspection area of a specific shape, and a reference for adjusting the irradiation position of measurement light during accuracy inspection. An inspection reference position 108 is provided. As shown in FIG. 27, the display 18 displays an inspection image obtained by imaging the chart body 105 irradiated with measurement light (for example, spot light SP) from the endoscope 12. Furthermore, in addition to the inspection area section 106 and the inspection reference position 108, a measurement marker M corresponding to the irradiation position of the measurement light is displayed on the inspection image.

As shown in FIG. 28, the moving mechanism section 104 holds the endoscope 12 in a state where the distal end 12d of the endoscope 12 faces the test chart 102, and also holds the test chart 102 movably. Specifically, the moving mechanism section 104 includes a base 109, an endoscope holding section 110 that is attached to the base 109 and holds the endoscope 12, and a moving mechanism section 104 that is attached to the base 109 and moves the test chart 102. It includes a chart holding section 112 that can hold the chart, and a movement amount adjusting section 114 that moves the chart holding section 112 in the vertical direction V or the horizontal direction W. Note that the movement amount adjustment unit 114 may be adjusted manually by the user or automatically. Calibration of the scale or position reference may be possible so that the distance between the test chart 102 and the distal end portion 12d of the endoscope can be accurately grasped. In order to accurately align the endoscope 12 with the test chart 102, the endoscope holder 110 and/or the angle fine adjustment mechanism is installed to make the optical axis Ax of the imaging optical system perpendicular to the test chart 102. Alternatively, it is preferable to have it on the base 109 or the moving mechanism section 104.

As described above, the movement mechanism section 104 operates the movement amount adjustment section 114 to move the chart holding section 112 in the vertical direction V or the horizontal direction W, thereby adjusting the emission position of the measurement light and the chart body 105. At least either the distance or the irradiation position of the measurement light on the chart body 105 can be changed. By moving the chart body 105 in the vertical direction W or the horizontal direction W via the chart holder 112, the irradiation position of the measurement light can be aligned with the test reference position in the test image.

The details of the test chart 102 will be explained. The inspection area section 106 provided in the test chart 102 is configured such that when the irradiation position of the measurement light is aligned with the inspection reference position in the inspection image, the measurement marker displayed on the inspection image based on the irradiation position has a specific shape. Used for confirmation inspection to see if it is within the inspection area. In this embodiment, in the test chart 102 in which the chart body 105 is provided with a plurality of inspection areas corresponding to the sizes of measurement markers, the confirmation inspection of each inspection area is performed based on the emission position of the measurement light and the chart body 105. The distance between the measurement light emission position and the chart body 105 is maintained constant for the test chart 102 (see FIG. 26), which is carried out in multiple sections by changing the distance between the two, and for the confirmation inspection of each inspection area. A test chart 120 (see FIG. 33) in which the test is performed once will be described.

As shown in FIG. 26, the test chart 102 includes three circular inspection areas 106a, 106b, and 106c as specific-shaped inspection areas. These circular inspection areas 106a to 106c are provided concentrically with the inspection reference position 108 as the center. The inspection areas 106a to 106c are point symmetrical with respect to the inspection reference position 108. The inspection areas 106a, 106b, and 106c are used for confirmation inspection of a 5 mm measurement marker, a 10 mm measurement marker, and a 20 mm measurement marker, respectively.

The width of the inspection area has an error range corresponding to the size of the measurement marker. Specifically, the width of the inspection area increases as the size of the measurement marker increases. In the case of the inspection area portion 106, the width Wp of the inspection area 106a<the width Wq of the inspection area 106b<the width Wr of the inspection area 106. This is because as the size of the measurement marker increases, it becomes more susceptible to the effects of misalignment of the chart body 105 in the chart holder 112 (see FIG. 28), making it difficult to perform accurate measurement marker confirmation inspection. It's for a reason. For example, if ±10% of the measurement marker is allowed as an error range for the width of the inspection area, the width of the inspection area 106a is designed to be 0.5 mm, and the width of the inspection area 106c is designed to be 2.0 mm.

When performing a confirmation inspection of a 5 mm measurement marker, the chart holding section 112 is moved in the vertical direction V by operating the movement amount adjustment section 114 to adjust the distance between the measurement light emission position and the chart body 105. is set to distance L1 (see FIG. 28). Then, the user moves the chart holder 112 in the left-right direction W while checking the inspection image displayed on the display 18 to align the irradiation position of the measurement light with the inspection reference position 108 .

As shown in FIG. 29, in the inspection image, if the measurement marker Mp is inside the inspection area 106a, the user determines that the 5 mm measurement marker Mp is properly displayed. On the other hand, as shown in FIG. 30, in the inspection image, when even a part of the measurement marker Mp does not enter the inspection area 106a, such as when the measurement marker M partially protrudes from the inspection area 106a, , the user determines that the 5 mm measurement marker Mp is not displayed properly.

Note that the inspection to confirm whether the measurement marker Mp is within the inspection area may be performed visually by the user or automatically using image processing (other measurement markers Mq, Mr. The same applies to In this case, it is preferable to provide the chart body 105 with a chart identifier 103 (for example, a QR code (registered trademark)) that can identify the type of the chart body. The type of the chart body 105 is read from the chart identifier 103 using a scanner or the like, and a measurement marker confirmation test is automatically performed based on the type of the chart body 105.

The type of the chart body 105a includes the number of times the confirmation test is performed (multiple times (in the case of the test chart 102) or once (in the case of the test chart 120)), the size of the test area provided in the test area section, etc. included. When the measurement marker confirmation test is automatically performed, the automatic judgment result of the confirmation test may be stored in the judgment result storage memory of the processor device 16. Further, in addition to the chart identifier 103, the chart body 105 is provided with a serial number or characters indicating the type of the chart body, in case the user performs a visual inspection.

When performing a confirmation inspection of the 10 mm measurement marker Mq, the chart holding section 112 is moved in the vertical direction V by operating the movement amount adjusting section 114 to adjust the distance between the measurement light emission position and the chart body 105. The distance is set to distance L2 (>distance L1) (see FIG. 28). Then, while checking the inspection image displayed on the display 18, the user moves the chart holder 112 in the left-right direction W to align the measurement light irradiation position with the inspection reference position 108. Then, as shown in FIG. 31, in the inspection image, it is determined whether the 10 mm measurement marker Mq is properly displayed depending on whether the measurement marker Mq is inside the inspection area 106a.

When performing a confirmation inspection of the 20 mm measurement marker Mr, the chart holding section 112 is moved in the vertical direction V by operating the movement amount adjustment section 114 to adjust the distance between the measurement light emission position and the chart body 105. The distance is set to distance L3 (>distance L1, L2) (see FIG. 28). Then, the user moves the chart holder 112 in the left-right direction W while checking the inspection image displayed on the display 18 to align the irradiation position of the measurement light with the inspection reference position 108 . Then, as shown in FIG. 32, in the inspection image, it is determined whether the 20 mm measurement marker Mr is properly displayed depending on whether the measurement marker Mr is within the inspection area 106a.

Further, the test chart 102 is provided with a confirmation test assisting section 111 for assisting the confirmation test (see FIG. 26). The confirmation inspection auxiliary section 111 when using the test chart 102 is eight radial lines extending radially from the inspection reference position 108 and intersecting each of the inspection areas 106a to 106c. These eight radial lines are line symmetrical and have equal angular spacing of 45 degrees. When performing a confirmation inspection, it may be difficult to visually confirm whether the measurement marker M is included in the entire inspection area. At certain points, it is possible to check whether the measurement marker M is within the inspection area. For example, if the measurement marker Mp is within the inspection area at all eight locations of the intersection CA, the user determines that the measurement marker Mp is properly displayed. On the other hand, if the measurement marker M is out of the inspection area at even one location in the intersection area CA, the user determines that the measurement marker Mp is not properly displayed.

As shown in FIG. 33, the test chart 120 includes three circular inspection areas 106a, 106b, and 106c as specific-shaped inspection areas. These three circular inspection areas 106a to 106c share one specific point. In the test chart 120, one specific point is set as the inspection reference position 108. The inspection areas 106a to 106c are symmetrical with respect to a line 108a passing through the inspection reference position 108. The inspection area 106a is used for confirmation inspection of the 5 mm measurement marker Mp, as described above. Furthermore, the inspection area 106b is used for confirmation inspection of the 10 mm measurement marker Mq, as described above. Further, the inspection area 106c is used for confirmation inspection of the 20 mm measurement marker Mr, similarly to the above.

By using the test chart 120, it is possible to perform a confirmation test on all the test areas 106a to 106c at one time. When performing a confirmation test using the test chart 120, the chart holding section 112 is moved in the vertical direction V by operating the movement amount adjusting section 114 to adjust the distance between the measurement light emission position and the chart body 105. Set to a specific distance (see FIG. 28). In addition, in the case of a confirmation inspection using the test chart 120, the display control unit 40 displays all measurement markers Mp, Mq, and Mr of 5 mm, 10 mm, and 20 mm on the inspection image based on the irradiation position of the measurement light. Do it like this. Then, the user moves the chart holder 112 in the left-right direction W while checking the inspection image displayed on the display 18 to align the irradiation position of the measurement light with the inspection reference position 108 .

As shown in FIG. 34, in the inspection image, when all the measurement markers Mp, Mq, and Mr displayed based on the irradiation position of the measurement light are inside the inspection areas 106a, 106b, and 106c, The user determines that the measurement markers Mp, Mq, and Mr of 5 mm, 10 mm, and 20 mm are displayed appropriately. On the other hand, as shown in FIG. 35, when the measurement marker Mp is in the inspection area 106a, while the measurement markers Mq and Mr are in the inspection areas 106b and 106c, the user can While it is determined that the measurement marker Mp is not displayed properly, it is determined that the measurement markers Mq and Mr of 10 mm and 20 mm are displayed properly.

Note that the inspection to confirm whether the measurement markers Mp, Mq, and Mr are within the inspection area may be performed visually by the user or may be performed automatically using image processing. In this case, in order to facilitate automatic detection of each of the inspection areas 106a, 106b, and 106c, it is preferable to maintain the hue of the inspection areas 106a, 106b, and 106c while varying the saturation. For example, it is preferable that the saturation of the inspection area 106a>the saturation of the inspection area 106b>the saturation of the inspection area 106c.

Regarding the test chart 120, when the measurement marker of the test object is circular, in addition to setting the specific shape of the test area to circular test areas 106a, 106b, and 106c, as shown in FIG. When the measurement marker is diamond-shaped, the specific-shaped inspection areas are set as diamond-shaped inspection areas 122a, 122b, and 122c in accordance with the shape of the measurement marker. The inspection areas 122a, 122b, and 122c are used for confirmation inspection of measurement markers of 5 mm, 10 mm, and 20 mm, respectively. Further, as shown in FIG. 37, when the measurement marker to be inspected is rectangular, the inspection areas of the specific shape are set as rectangular inspection areas 124a, 124b, and 124c in accordance with the shape of the measurement marker. The inspection areas 124a, 124b, and 124c are used for confirmation inspection of measurement markers of 5 mm, 10 mm, and 20 mm, respectively.

Regarding the test chart 102 and the test chart 120, the hue of the measurement light when irradiated on the chart body 105 is the same as the hue of the measurement light when irradiated on the actual subject (human body such as esophagus, stomach, large intestine, etc.). It is preferable to set the hue of the chart body 105 so that Here, the term "the hues are the same" includes not only cases in which the respective hues completely match, but also cases in which the difference in hue between each other (difference in hue value) is within a certain range. Note that the inspection area and the areas other than the inspection area of the chart body 105 have the same hue for the above reason (to have the same hue as the measurement light on the subject), but the inspection area and the other areas have the same hue. The color saturation is different to make it easier to identify.

As described above, in order to set the hue of the chart body 105, in the test chart 102, as shown in FIG. An inspection area section 106 is provided. The inspection area portion 106 is preferably printed using toner or offset printing ink using a laser printer or the like. Then, the inspection area portion 106 is covered with the tracing paper 105c. Here, it is preferable that the PSF plate 105a has high reflectance and some light scattering. On the other hand, the tracing paper 105c preferably has an average reflectance and light scattering rate of mucous membranes of subjects such as the esophagus, stomach, and large intestine. As described above, by configuring the test chart 102, the hue of the measurement light when irradiating the chart body 105 is the same as the hue of the measurement light when irradiating the actual subject (human body such as esophagus, stomach, large intestine, etc.). becomes the same as Therefore, even when the test chart 102 is irradiated with the measurement light, the reflectance of the test chart 102 is the same as the reflectance of the subject, so the irradiation position detection unit 58 of the processor device 16 detects the measurement light ( Spot light) can be reliably detected.

Note that when spot light is used as the measurement light, a test chart 102 and a test chart 120 (see FIGS. 26 and 33) for spot light are used in which the inspection reference position corresponds to the spot light. When a line-shaped measurement light is used as the light, as shown in FIG. 39, a line test chart 130 in which the inspection reference position 128 corresponds to the line-shaped measurement light is used to perform a confirmation inspection of the measurement marker. It is preferable to do this. In addition, when using a patterned measurement light as the measurement light, as shown in FIG. It is preferable to conduct a confirmation test of the marker, and another method is to use a test chart with a tolerance range according to the shape of the marker (arbitrary depending on the design purpose) generated from the patterned measurement light. It is possible. That is, the test chart 102 of this embodiment can be applied mutatis mutandis as long as it is possible to generate and display a horizontal line-shaped or approximately elliptical marker from a pattern of measurement light.

Next, a series of steps in the calibration mode will be explained along the flowchart of FIG. 41. In the inspection system 100, the test chart 102 is placed on the chart holder 112, and the endoscope 12 is attached to the endoscope holder 110 with the distal end 12d of the endoscope and the test chart 102 facing each other. Then, by operating the mode changeover switch 13a, the mode is switched to calibration. As a result, measurement light is emitted from the endoscope 12 toward the test chart 102 .

The endoscope 12 obtains an inspection image by capturing an image of the chart body 105 irradiated with measurement light. The test image is displayed on the display 18. In the inspection image, a measurement marker is displayed in accordance with the irradiation position of the measurement light. The user checks the inspection image and operates the movement amount adjustment unit 114 so that the measurement light irradiation position matches the inspection reference position 108, and adjusts the distance between the measurement light emission position and the chart body 105, or , at least one of the measurement light irradiation positions on the chart body 105 is changed. Then, when the irradiation position of the illumination light matches the inspection reference position, the user performs a confirmation inspection to see whether the measurement marker is properly displayed.

Regarding the confirmation inspection when using the test chart 102, first, move the chart body 105 in the vertical direction V or the horizontal direction W by operating the movement amount adjusting section 114 so that the 5 mm measurement marker Mp enters the inspection area 106a. move it. Then, when the irradiation position of the measurement light is aligned with the inspection reference position 108, if the measurement marker Mp is inside the inspection area 106a in the inspection image, the measurement marker Mp is properly displayed. It is determined that there is. If the measurement marker Mp is not within the inspection area 106a, it is determined that the measurement marker Mp is not properly displayed.

Next, the chart body 105 is moved in the vertical direction V or the horizontal direction W so that the 10 mm measurement marker Mq enters the inspection area 106b. Then, when the measurement light irradiation position is aligned with the inspection reference position 108, it is determined whether the measurement marker Mq is inside the inspection area 106a in the inspection image, as in the case of the 5 mm measurement marker Mp. to decide. Next, after the confirmation test regarding the test marker Mq is completed, the chart body 105 is moved in the vertical direction V or the horizontal direction W so that the 20 mm measurement marker Mr enters the test region 106c. Then, when the measurement light irradiation position is aligned with the inspection reference position 108, it is determined whether the measurement marker Mr is inside the inspection area 106c in the inspection image, as in the case of the 5 mm measurement marker Mp. to decide. With the above steps, the confirmation test using the test chart 102 at a specific distance is completed. The process up to this point can be repeated at one or more preset distances between the endoscope and the chart, and it is possible to determine whether the product is acceptable or not based on the criteria.

In the above embodiment, the receiving section 38, the signal processing section 39, the display control section 40, the system control section 41, the still image storage section 42, the first signal processing section 50, the second signal processing section 52, the mode control section 56, the irradiation The hardware structure of a processing unit that executes various processes, such as the position detection unit 58 and the marker table 62, is the following various processors. Various types of processors include CPUs (Central Processing Units) and FPGAs (Field Programmable Gate Arrays), which are general-purpose processors that execute software (programs) and function as various processing units.The circuit configuration is changed after manufacturing. These include a programmable logic device (PLD), which is a capable processor, and a dedicated electric circuit, which is a processor having a circuit configuration specially designed to execute various types of processing.

One processing unit may be composed of one of these various types of processors, or may be composed of a combination of two or more processors of the same type or different types (for example, multiple FPGAs or a combination of a CPU and FPGA). may be done. Further, the plurality of processing units may be configured with one processor. As an example of configuring multiple processing units with one processor, first, as typified by computers such as clients and servers, one processor is configured with a combination of one or more CPUs and software, There is a form in which this processor functions as a plurality of processing units. Second, there are processors that use a single IC (Integrated Circuit) chip to implement the functions of an entire system including multiple processing units, as typified by System On Chip (SoC). be. In this way, various processing units are configured using one or more of the various processors described above as a hardware structure.

Furthermore, the hardware structure of these various processors is, more specifically, an electric circuit (circuitry) in the form of a combination of circuit elements such as semiconductor elements. Further, the hardware structure of the storage unit is a storage device such as an HDD (hard disc drive) or an SSD (solid state drive).

Note that the measurement light and the measurement light irradiation are preferably as follows. Preferably, the measurement light is spot light. Preferably, the measurement light is a line-shaped measurement light. Preferably, the measurement light has a grid pattern. Preferably, the measurement light is three-dimensional plane light. It is preferable to intermittently irradiate the subject with measurement light. Preferably, the measurement light is striped pattern light. It is preferable that a plurality of striped pattern lights having different phases or periods are switched and irradiated to the subject.

10 Endoscope system 12 Endoscope 12a Insertion section 12b Operation section 12c Curved section 12d Tip section 13a Mode changeover switch 13b Freeze switch 13c Zoom operation section 14 Light source device 16 Processor device 18 Display 20 User interface 21 Imaging optical system 21a Objective lens 21b Zoom lens 22 Illumination optical system 22a Illumination lens 23 Beam light emitting section 23a Light source 23b DOE
23c Prism 23d Emission section 24 Opening 25 Air/water supply nozzle 26 Light source section 27 Light source control section 28 Light guide 29 Connector 32 Image sensor 33 Image control section 34 CDS/AGC circuit 35 A/D converter 36 Communication I/F
37 Communication I/F
38 Receiving section 39 Signal processing section 40 Display control section 41 System control section 42 Still image storage section 50 First signal processing section 52 Second signal processing section 56 Mode control section 58 Irradiation position detection section 62 Marker table 80 Intersection line 82 Scale 100 Inspection system 101a Solid line 101b Dotted line 102 Test chart 103 Chart identifier 104 Moving mechanism section 105 Chart body 105a PSF board 105b Adhesive sheet 105c Tracing paper 106 Inspection area sections 106a, 106b, 106c Inspection area 108 Inspection reference position 108a Line 109 Base 110 Endoscope holding section 111 Confirmation inspection auxiliary section 112 Chart holding section 114 Movement amount adjustment section 120 Test charts 122a, 122b, 122c Inspection areas 124a, 124b, 124c Inspection area 128 Inspection reference position 130 Test chart 132 Inspection reference position 134 Test Charts M1, M2, M3 Cross-shaped markers tm1, tm2, tm3, tm4, tm5 Tumor SP Spots SP1, SP2, SP3, SP4, SP5 Spots M4A, M4B, M4C, M5A, M5B, M5C Concentric markers M6A, M6B , M6C Distorted concentric marker P Polyp

Claims (23)

In the test chart used for inspection regarding measurement markers for measuring the size of the subject,
It has a chart body provided with an inspection area portion having an inspection area of a specific shape and an inspection reference position,
The inspection area section is
In an inspection image obtained by imaging the chart body irradiated with measurement light with an endoscope, when the irradiation position of the measurement light is aligned with the inspection reference position, the inspection image is adjusted based on the irradiation position. A test chart used for a confirmation test to determine whether the displayed measurement marker is within the test area. The chart body is provided with a plurality of inspection areas corresponding to the size of the measurement marker,
2. The test chart according to claim 1, wherein the confirmation test for each test area is performed in a plurality of parts by changing the distance between the emission position of the measurement light and the chart body. 3. The test chart according to claim 2, wherein the chart body has a confirmation inspection auxiliary part for assisting the confirmation inspection. the specific shape is circular;
The plurality of inspection areas are provided concentrically around the inspection reference position,
4. The test chart according to claim 3, wherein the confirmation inspection auxiliary part is a plurality of radial lines extending radially from the inspection reference position and intersecting the inspection area. 5. The test chart according to claim 4, wherein the angular intervals of the radial lines are equal angular intervals. 5. The test chart according to claim 4, wherein the radial lines are symmetrical. The test chart is provided with a plurality of inspection areas corresponding to the size of the measurement marker,
2. The test chart according to claim 1, wherein the confirmation test for each test area is performed once while maintaining a constant distance between the emission position of the measurement light and the chart body. the specific shape is circular;
8. The test chart according to claim 7, wherein the plurality of inspection areas share one specific point in each inspection area as the inspection reference position. 9. The test chart according to claim 7, wherein the plurality of test areas have different saturations. 10. The test chart according to claim 1, wherein the hue of the measurement light applied to the chart body is the same as the hue of the measurement light applied to the subject. 11. The test chart according to claim 1, wherein the inspection area and the area other than the inspection area of the chart body have the same hue. 12. The test chart according to claim 1, wherein the width of the inspection area has an error range corresponding to the size of the measurement marker. 13. The test chart according to claim 12, wherein the width of the inspection area increases as the size of the measurement marker increases. The test chart according to any one of claims 1 to 13, further comprising a chart identifier that can identify the type of the chart body. a test chart having a chart body provided with an inspection reference position;
a display that displays an inspection image obtained by imaging the chart body irradiated with measurement light from the endoscope with the endoscope;
a moving mechanism section that holds the endoscope in a state where the distal end of the endoscope faces the test chart, and movably holds the test chart;
Equipped with
The moving mechanism section changes at least one of the distance between the emission position of the measurement light and the chart body, or the irradiation position of the measurement light on the chart body, thereby changing the measurement light in the inspection image. An inspection system that aligns an irradiation position with the inspection reference position. The chart body has an inspection area portion having an inspection area of a specific shape,
The inspection area section is
In an inspection image obtained by imaging the chart body irradiated with the measurement light with the endoscope, when the irradiation position of the measurement light is aligned with the inspection reference position, the inspection is performed based on the irradiation position. 16. The inspection system according to claim 15, wherein the inspection system is used to confirm whether a measurement marker displayed on an image is within the inspection area. The test chart is provided with a plurality of inspection areas corresponding to the size of the measurement marker,
The moving mechanism unit changes the distance between the emission position of the measurement light and the chart body for each confirmation inspection of each inspection area,
17. The inspection system according to claim 16, wherein each time the distance is changed, the display displays a measurement marker corresponding to the distance, thereby performing a confirmation inspection of each inspection area in a plurality of parts. The test chart is provided with a plurality of inspection areas corresponding to the size of the measurement marker,
The moving mechanism section maintains a constant distance between the emission position of the measurement light and the chart body,
17. The inspection system according to claim 16, wherein the display performs a confirmation inspection of all inspection areas at one time by displaying all measurement markers corresponding to the plurality of inspection areas. The inspection system according to any one of claims 15 to 18, wherein the measurement light is a spot light. The inspection system according to any one of claims 15 to 18, wherein the measurement light is a line-shaped measurement light. The inspection system according to any one of claims 15 to 18, wherein the measurement light is patterned measurement light. The inspection system according to any one of claims 15 to 18, wherein the measurement light is a three-dimensional plane light. In an inspection method for inspecting a measurement marker for measuring the size of a subject using a test chart having an inspection area portion having an inspection area of a specific shape and a chart body having an inspection reference position,
obtaining an inspection image by imaging the chart body irradiated with measurement light from the endoscope with the endoscope;
Displaying the inspection image on a display;
By changing at least either the distance between the emission position of the measurement light and the chart body or the irradiation position of the measurement light on the chart body, the irradiation position of the measurement light can be adjusted in the inspection image in the inspection image. a step of aligning with the reference position ;
In the inspection image, when the irradiation position of the measurement light is aligned with the inspection reference position, checking whether the measurement marker displayed on the inspection image is within the inspection area based on the irradiation position. An inspection method comprising the step of performing an inspection .

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