JP2016059389A - Endoscope system and endoscopic image display method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope system capable of providing an observer with highly visible images in multiple modes having different depths of field.SOLUTION: An endoscope system comprises an endoscope 2 and a processor device 3 to display image data captured by the endoscope 2 onto a monitor 5. The endoscope 2 includes a movable lens 22 movable in a direction of an optical axis by an actuator 23, an optical system 21 to change a depth of field with a movement of the movable lens 22, and a controller 25. The controller 25 causes the actuator 23 to repeatedly move the movable lens 22 to multiple lens positions P1 to P2 corresponding to multiple modes having depths of field different from each other and an imager 24 to sequentially capture images at the lens positions P1 to P2. The processor device 3 evaluates focusing of each mode on the basis of the image data of the mode and displays the image data of one mode with the relatively highest evaluation onto the monitor 5 in movie.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an endoscope system and an endoscope image display method.

  An endoscope system is known in which images of a plurality of modes having different imaging magnifications and depths of field are captured and these images are displayed simultaneously or alternately (for example, see Patent Documents 1 to 3). .

  An endoscope used in the endoscope system described in Patent Document 1 includes a first optical system and a first image sensor for normal observation, and a second optical for magnification observation at a higher magnification than normal observation. The system and the second image sensor are provided, and the normal observation image and the enlarged observation image are acquired simultaneously. The captured normal observation image and enlarged observation image are simultaneously displayed on the monitor.

  An endoscope used in the endoscope system described in Patent Document 2 includes a first optical system for normal observation, a second optical system for magnified observation, a first optical system, and a second optical system. And an image pickup device for picking up images through each of the image pickup device, and simultaneously picking up a normal observation image and an enlarged observation image. The captured normal observation image and enlarged observation image are simultaneously displayed on the monitor.

  The endoscope used in the endoscope system described in Patent Document 3 includes one optical system including a movable lens that can move along the optical axis, and one imaging element, and moves the movable lens. By changing the focal length, it is possible to perform close-up observation close to the subject, and the position of the movable lens can be switched alternately between the focus position on the near point side and the focus position on the far point side. Images of multiple modes with different depths of field are captured alternately. Images in a plurality of modes with different depths of field are alternately displayed on the monitor in synchronization with the imaging of each image, and the blurred portions are mutually complemented and recognized by the afterimage effect due to human visual characteristics.

JP 2010-154957 A JP 2006-122129 A Japanese Patent Laid-Open No. 10-225438

  In the endoscope systems described in Patent Documents 1 and 2, a plurality of optical systems and image sensors are provided to simultaneously capture a normal observation image and a magnified observation image, which hinders the diameter reduction of the endoscope. There is a possibility of causing. In addition, since the captured normal observation image and enlarged observation image are displayed on the monitor at the same time, the display size of each image is reduced, and there is a possibility that the movement of the line of sight between the images becomes a burden on the observer. .

  In the endoscope system described in Patent Document 3, a single optical system and an image sensor are sufficient for alternately capturing images of a plurality of modes with different depths of field, thereby reducing the diameter of the endoscope. It is advantageous. However, if the magnifications of the plurality of alternately displayed images are slightly different due to the change in the angle of view accompanying the change in the focal length, there is a possibility that the observer may feel uncomfortable.

  The present invention has been made in view of the above circumstances, and is an endoscope capable of capturing images of a plurality of modes with different depths of field and presenting the captured images of the plurality of modes to an observer with high visibility. It is an object to provide a system and an endoscopic image display method.

  An endoscope system according to an aspect of the present invention includes an endoscope having an image sensor, and a processor device that displays on a monitor image data acquired by the image sensor of the endoscope. The endoscope includes at least one movable lens that is moved in an optical axis direction by an actuator, and an optical that changes a focal length and changes a depth of field by moving the movable lens. A system and a control unit, wherein the control unit causes the actuator to repeatedly move the movable lens to each of a plurality of lens positions corresponding to a plurality of modes having different depths of field. The image at the lens position is sequentially picked up by the image sensor, and the processor device performs matching for each mode based on the image data of each mode acquired by the endoscope. Evaluate the conditions, relatively evaluated to video displayed on the monitor image data of the highest one mode.

  The endoscope image display method according to one aspect of the present invention is based on image data of each mode based on image data of each mode acquired by an endoscope that sequentially captures images of a plurality of modes having different depths of field. The in-focus state is evaluated, and the image data of one mode having the highest evaluation is displayed as a moving image on the monitor.

  According to the present invention, there is provided an endoscope system and an endoscope image display method capable of capturing images of a plurality of modes with different depths of field and presenting the captured images of the plurality of modes to an observer with high visibility. Can be provided.

It is a figure showing composition of an example of an endoscope system for explaining an embodiment of the present invention. It is a figure which shows the functional block of the endoscope system of FIG. It is a figure which shows the detailed functional block of the processor apparatus of the endoscope system of FIG. It is a figure which shows the structure of an example of the imaging optical system of the endoscope system of FIG. It is a figure which shows the structure of an example of the imaging device of the endoscope system of FIG. It is a figure which shows the structure of an example of the imaging device of the endoscope system of FIG. The main part of the imaging device of FIG. It is a figure which shows the structure of the modification of the imaging device of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows an exemplary configuration of an endoscope system for explaining an embodiment of the present invention, and FIGS. 2 and 3 show functional blocks of the endoscope system of FIG.

  The endoscope system 1 includes an endoscope 2, a processor device 3, a light source device 4, and a monitor 5.

  The endoscope 2 includes an insertion unit 10 that is inserted into a subject, an operation unit 11 that is connected to the insertion unit 10, and a universal cord 12 that extends from the operation unit 11. The endoscope 2 is connected to the processor device 3 and the light source device 4 via the universal cord 12.

  The light source device 4 includes, for example, a light source 40 such as a halogen lamp, a xenon lamp, or a light-emitting diode, and illumination light generated by the light source 40 is generated inside the universal cord 12, the operation unit 11, and the insertion unit 10 of the endoscope 2. The light guide 41 inserted through the light guide 41 is guided to the distal end portion 13 of the insertion portion 10 and irradiated from the distal end surface of the light guide 41 toward the subject.

  The distal end portion 13 of the insertion portion 10 of the endoscope 2 is provided with an imaging device 20 that captures an image of the subject illuminated by the illumination light.

  The imaging device 20 includes an imaging optical system 21 including a movable lens 22 that is moved in the optical axis direction, an actuator 23 that moves the movable lens 22, a CCD (Charge Coupled Device) image sensor, and a CMOS (Complementary Metal Oxide Semiconductor) image. An image sensor 24 such as a sensor and an endoscope control unit 25 are included.

  The imaging optical system 21 is configured to change the focal length according to the movement of the movable lens 22 in the optical axis direction, thereby changing the depth of field, and to perform close-up observation close to the subject. In this example, two positions, that is, the first position P1 on the near point side and the second position P2 on the far point side are set as positions of the movable lens 22, but three or more positions are set. May be.

  The endoscope control unit 25 causes the actuator 23 to repeatedly move the movable lens 22 to each of the first position P1 and the second position P2. Then, the control unit 25 displays the first mode image when the movable lens 22 is disposed at the first position P1 and the second mode image when the movable lens 22 is disposed at the second position P2. The image sensor 24 is sequentially imaged.

  The processor device 3 includes an image processing unit 30 to which the first mode image data and the second mode image data output from the imaging device 20 are input, and a processor control unit that performs overall control of the image processing unit 30 and the imaging device 20. 31. The image processing unit 30 includes a correction unit 32, an input selector unit 33, frame memories 34 and 35, an evaluation value calculation unit 36, and an output selector unit 37.

  The processor control unit 31 acquires from the endoscope control unit 25 whether the imaging timing and the image data acquired at that timing is the image data of the first mode or the image data of the second mode. .

  The correction unit 32 performs various correction processes such as white balance correction on the first mode image data and the second mode image data input to the image processing unit 30.

  The input selector unit 33 selects one of the frame memories 34 and 35 under the control of the processor control unit 31, stores the first mode image data in the frame memory 34, and stores the second mode in the frame memory 35. The image data is stored.

  The evaluation value calculation unit 36 calculates an evaluation value for evaluating the in-focus state for each mode based on the first mode image data stored in the frame memory 34 and the second mode image data stored in the frame memory 35. To calculate.

  The output selector unit 37 selects one of the frame memories 34 and 35 under the control of the processor control unit 31, and outputs the image data stored in the selected frame memory to the monitor 5.

  The processor control unit 31 evaluates the in-focus state for each mode based on the evaluation value for each mode calculated by the evaluation value calculation unit 36, and the evaluation is relatively high among the first mode and the second mode. Specify one mode. In addition, when the evaluation value of 1st mode and 2nd mode is equal, it sets beforehand so that any one mode may be prioritized.

  As the evaluation value, the contrast value of the image data can be used, and it can be considered that the subject is in focus as the contrast value is large, and the evaluation of the in-focus state is high.

  Then, the processor control unit 31 controls the output selector unit 37 so that the frame memory storing the image data of one mode in which the evaluation of the in-focus state is high among the frame memories 34 and 35 is selected.

  In the endoscope system 1 configured as described above, one of the images in the first mode and the image in the second mode that is in focus is displayed on the monitor 5, and the endoscope 2. The image displayed on the monitor 5 is automatically switched to the first mode image or the second mode image according to the distance between the distal end portion 13 of the insertion portion 10 and the subject.

  For example, the first mode when the movable lens 22 is arranged at the first position P1 on the near point side when the distal end portion 13 of the insertion portion 10 of the endoscope 2 is gradually approached to the subject for the close observation. When the movable lens 22 is disposed at the second position P2 on the far point side, the image in the second mode is gradually out of focus, and the predetermined distance between the tip 13 and the subject is gradually increased. The image displayed on the monitor 5 automatically switches from the second mode image to the first mode image.

  As described above, the endoscope system 1 does not require a switching operation of the position of the movable lens 22 in the transition from the normal observation to the close observation and the transition from the close observation to the normal observation, thereby improving convenience. Can do.

  In the endoscope system 1, one of the first mode image and the second mode image that is in focus can be automatically displayed on the monitor 5 and presented to the observer. Therefore, the visibility can be improved as compared with the case where the image in the first mode and the image in the second mode are displayed on the monitor 5 simultaneously or alternately.

  Here, as shown in FIG. 4, the depth of field of the imaging optical system 21 in the first mode and the depth of field of the imaging optical system 21 in the second mode partially overlap. It is preferable. According to this, an image that is always in focus can be presented to the observer.

  The acquisition frequency of the image data in the first mode and the acquisition frequency of the image data in the second mode can be set in consideration of the image display rate on the monitor 5.

  For example, if the display rate of the image on the monitor 5 is 30 fps, the first mode image and the second mode image are alternately captured at 60 fps, and the first mode image data acquisition frequency and the second mode are obtained. The acquisition frequency of the image data can be set to 30 fps.

  Further, in the endoscope control unit 25, the evaluation result of the evaluation value for each mode by the processor control unit 31 is acquired. Based on the acquired evaluation result, the acquisition frequency of the first mode image data and the image data of the second mode You may make it change the acquisition frequency of each.

  For example, when the image display rate on the monitor 5 is 30 fps, the evaluation value is relatively highest, the acquisition frequency of the image data of the mode output to the monitor 5 is 30 fps, and the image data of other modes Can be obtained at a frequency of less than 30 fps.

  As described above, the image data acquisition rate in the mode with the relatively highest evaluation value is increased, and the image data acquisition frequency in the other modes is decreased, thereby suppressing the image capturing rate of the image capturing apparatus 20 to be low. Therefore, for example, it is possible to use an image pickup device whose operation speed is relatively low, and to secure an exposure time for each image pickup.

  Next, the configuration of the imaging device 20 that sequentially captures the first mode image and the second mode image will be described.

  FIG. 5 is a diagram illustrating a configuration of an example of the imaging device 20.

  As described above, the imaging apparatus of the example illustrated in FIG. 5 includes the imaging optical system 21 including the movable lens 22 and the imaging element 24 that images a subject through the imaging optical system 21.

  The movable lens 22 is a lens that switches a focal length, and is configured by at least one lens. The movable lens 22 is held by a movable lens holding member 50 that is movable in the optical axis direction of the imaging optical system 21.

  A prism 51 is provided behind the movable lens 22. The prism 51 causes the light incident on the imaging optical system 21 to be bent by approximately 90 degrees and enter the imaging element 24. The imaging element 24 may be disposed on the optical axis J1 behind the movable lens 22 by omitting the prism 51.

  In the image pickup apparatus shown in FIG. 5, a linear actuator is used as the actuator 23 (see FIG. 2). In the example shown in the figure, a shape memory alloy (Shape Memory) that contracts when heated and expands when cooled. Alloys) wire 52 is used. The SMA wire 52 extends parallel to the optical axis J1 of the imaging optical system.

  The distal end portion of the SMA wire 52 is fixed to the movable lens holding member 50, and the proximal end portion of the SMA wire 52 is inserted through the insulating tube 53. A coil spring 54 is interposed between the movable lens holding member 50 and the insulating tube 53. The coil spring 54 urges the movable lens holding member 50 toward the subject in the extending direction of the SMA wire 52.

  A cable 55 for applying a current to the SMA wire 52 is connected to the proximal end portion of the SMA wire 52, and a GND cable (not shown) is connected to the distal end portion of the SMA wire 52.

  When a current flows through the SMA wire 52 via the cable 55 and the GND cable, the SMA wire 52 generates heat and contracts, and the movable lens holding member 50 is pulled to the image side by the SMA wire 52 and provided in the housing 57. It abuts against the stopper portion 58. Thereby, the movable lens 22 is disposed at the first position P1.

  When the application of current to the SMA wire 52 is stopped, the SMA wire 52 is naturally cooled and expanded, and the movable lens holding member 50 is urged toward the subject side by the coil spring 54 and provided in the housing 57. Abuts against the stopper portion 59. Thereby, the movable lens 22 is disposed at the second position P2.

  In the imaging apparatus configured as described above, application and stop of the current to the SMA wire 52 are repeatedly performed, whereby the movable lens 22 is repeatedly moved to each of the first position P1 and the second position P2. Is called. The first mode image when the movable lens 22 is disposed at the first position P1 and the second mode image when the movable lens 22 is disposed at the second position P2 are alternately or arbitrarily. The image is taken in a repeated cycle.

  In addition, as a linear actuator, the linear actuator using the electromagnetic coil as described in Unexamined-Japanese-Patent No. 10-225438 can also be used, for example.

  FIG. 6 is a diagram illustrating the configuration of another example of the imaging device 20.

  The image pickup apparatus shown in FIG. 6 uses a rotary actuator as the actuator 23 (see FIG. 2). In the example shown, the image pickup apparatus is juxtaposed with the image pickup optical system 21 and parallel to the optical axis J1 of the image pickup optical system 21. The shaft member 60 is configured to be rotatable about a rotating shaft J2, and the driving unit 61 includes a motor that rotates the shaft member 60.

  An object-side end (tip portion) 60 </ b> A of the shaft member 60 is rotatably supported by a tip-side support portion 62 fixed to the housing 57. An end portion (rear end portion) 60B on the image side of the shaft member 60 is rotatably supported by a housing 57 and a rear end side support portion 63 fixed to the housing 57.

  A movable lens holding member 50 is fitted to the distal end portion 60A of the shaft member 60 so as to be movable along the rotation axis J2.

  A rotating shaft 64 is fixed to the rear end portion 60B of the shaft member 60. The rotation shaft 64 is connected to the drive unit 61, and the shaft member 60 receives the rotation driving force of the drive unit 61 and is rotated about the rotation axis J2. In addition, the drive part 61 may be provided in the operation part 11 (refer FIG. 1), and the rotation shaft 64 is connected with the drive part 61 via the wire in that case.

  The shaft member 60 rotated about the rotation axis J2 is provided with a cam portion 65 for moving the movable lens 22 along the optical axis J1 parallel to the rotation axis J2. A pin (follower) 66 that contacts the cam portion 65 is fixed to the movable lens holding member 50.

  A coil spring 67 is interposed between the distal end side support portion 62 that supports the distal end portion 60A of the shaft member 60 and the movable lens holding member 50 that is fitted to the distal end portion 60A of the shaft member 60. The coil spring 67 urges the pin 66 fixed to the movable lens holding member 50 from the distal end side of the shaft member 60 toward the cam portion 65 along the rotation axis J2.

  FIG. 7A and FIG. 7B show the configuration of the shaft member 60.

  The diameter of the front end portion 60A of the shaft member 60 is smaller than the diameter of the rear end portion 60B, and the cam portion 65 is provided at a step between the front end portion 60A and the rear end portion 60B.

  The cam portion 65 includes a first cam surface 65a and a second cam surface 65b, and a third cam surface 65c disposed between one end of the first cam surface 65a and the second cam surface 65b. The first cam surface 65a to the third cam surface 65c are connected and formed to extend in the circumferential direction around the rotation axis J2.

  The first cam surface 65a and the second cam surface 65b are flat surfaces whose positions on the rotation axis J2 are constant in the circumferential direction, and the positions of the first cam surface 65a and the second cam surface 65b on the rotation axis J2 are set. Are different from each other. The third cam surface 65c is a slope whose position on the rotation axis J2 continuously changes in the circumferential direction.

  The cam portion 65 further includes stopper surfaces 65e and 65f with which the pin 66 can contact in the circumferential direction. The stopper surface 65e is provided at the end opposite to one end in the circumferential direction of the first cam surface 65a connected to the third cam surface 65c. The stopper surface 65f is provided at the end opposite to one end in the circumferential direction of the second cam surface 65b connected to the third cam surface 65c.

  The shaft member 60 is rotationally driven in the forward direction by the drive unit 61. As the shaft member 60 rotates, the pin 66 slides on the cam unit 65 and is stopped against the stopper surface 65 e of the cam unit 65. It arrange | positions at the 1st cam surface 65a. Thereby, the movable lens 22 is disposed at the first position P1.

  Further, the shaft member 60 is rotationally driven in the reverse direction by the driving portion 61, and the pin 66 slides on the cam portion 65 along with the rotation of the shaft member 60 and is stopped against the stopper surface 65 f of the cam portion 65. The second cam surface 65b is disposed. Thereby, the movable lens 22 is disposed at the second position P2.

  In the imaging apparatus configured as described above, the drive unit 61 repeatedly performs the rotation drive in the forward direction and the rotation drive in the reverse direction of the shaft member 60, whereby each of the first position P1 and the second position P2 is performed. The movement of the movable lens 22 is repeatedly performed. The first mode image when the movable lens 22 is disposed at the first position P1 and the second mode image when the movable lens 22 is disposed at the second position P2 are alternately or arbitrarily. The image is taken in a repeated cycle.

  The above-described configuration of the cam portion 65 is an example. For example, in the middle of the third cam surface 65c, the position on the rotation axis J2 is constant in the circumferential direction, and the first cam surface 65a and the second cam surface 65b are A different flat surface may be further provided, and the cam unit 65 may be configured so that the focal length of the imaging device can be switched to three or more stages. In this case, the pin 66 is disposed on the flat surface provided in the middle of the third cam surface 65c by the rotation control of the shaft member 60 by the drive unit 61 without depending on the stopper. Since the position on the rotation axis J2 is constant in the circumferential direction, the positional accuracy of the movable lens 22 can be maintained even if a slight error occurs in the rotation of the shaft member 60.

  FIG. 8 is a diagram illustrating a configuration of a modification of the imaging apparatus illustrated in FIG.

  In the example of the imaging apparatus shown in FIG. 8, the rotation axis J <b> 2 is disposed between the opposite ends of the first cam surface 65 a and the second cam surface 65 b on which the third cam surface 65 c is disposed. A fourth cam surface 65d, which is an inclined surface whose position continuously changes in the circumferential direction, is further provided, and the cam portion 65 is configured in a loop shape that circulates around the rotation axis J2.

  In the imaging apparatus configured as described above, the shaft member 60 is rotationally driven in one direction by the drive unit 61, and the pin 66 slides on the cam unit 65 along with the rotation of the shaft member 60, and the first cam surface 65a. And the second cam surface 65b is alternately and repeatedly disposed. When the pin 66 is on the first cam surface 65a, the movable lens 22 is disposed at the first position P1, and when the pin 66 is on the second cam surface 65b, the movable lens 22 is disposed at the second position P2. The first mode image when the movable lens 22 is disposed at the first position P1 and the second mode image when the movable lens 22 is disposed at the second position P2 are alternately or arbitrarily. The image is taken in a repeated cycle.

  In this example, the movable lens 22 can be repeatedly and alternately arranged at the first position P1 and the second position P2 by rotational driving in one direction of the shaft member 60, and the SMA wire 52 is arranged in the imaging apparatus shown in FIG. The apparatus configuration can be simplified as compared with the case where the shaft member 60 is repeatedly expanded and contracted, or the shaft member 60 is repeatedly rotated in the forward and reverse directions in the imaging apparatus shown in FIG.

  In this example, the movable lens 22 is positioned without depending on the contact of the movable lens holding member 50 or the pin 66, and the deformation or loss of the movable lens holding member 50 or the pin 66 due to the impact caused by the contact is suppressed. The operational reliability and durability of the imaging device can be improved.

  Three or more flat surfaces whose positions on the rotation axis J2 are constant in the circumferential direction are provided, and two flat surfaces adjacent in the circumferential direction are inclined surfaces whose positions on the rotation axis J2 continuously change in the circumferential direction. The focal lengths of the imaging devices may be switched between three or more stages so as to be connected to each other.

  As described above, the endoscope system disclosed in this specification includes an endoscope having an image sensor and a processor device that displays image data acquired by the image sensor of the endoscope on a monitor. An endoscope system comprising: at least one movable lens that is moved in an optical axis direction by an actuator; and the focal length is changed by moving the movable lens; An optical system for changing the depth of field; and a control unit, wherein the control unit moves the movable lens to each of a plurality of lens positions corresponding to a plurality of modes having different depths of field. The actuator is repeatedly performed, and the image at each lens position is sequentially picked up by the image sensor. The processor device is an image of each mode acquired by the endoscope. It evaluates the focus state of each mode based on chromatography data, relatively evaluated to video displayed on the monitor image data of the highest one mode.

  In addition, in the endoscope system disclosed in this specification, the depth of field of the optical system partially overlaps in two modes in which the position of the movable lens is adjacent among the plurality of modes. .

  In addition, in the endoscope system disclosed in this specification, the processor device calculates a contrast value of the image data as an evaluation index of a focused state, and image data in a mode in which the contrast value is relatively maximum. On the monitor.

  In the endoscope system disclosed in this specification, the control unit of the endoscope changes the acquisition frequency of image data in each mode based on the evaluation by the processor device.

  Further, in the endoscope system disclosed in this specification, the endoscope is rotated by the actuator about a rotation axis parallel to the optical axis of the optical system, and circulates around the rotation axis. A shaft member having a cam portion; and a movable lens holding member having a follower sliding on the cam portion and moved back and forth along the shaft member as the shaft member rotates.

  Further, the endoscopic image display method disclosed in this specification is based on the image data of each mode based on the image data of each mode acquired by an endoscope that sequentially captures images of a plurality of modes having different depths of field. The in-focus state is evaluated, and the image data of one mode having the highest evaluation is displayed as a moving image on the monitor.

  The endoscopic image display method disclosed in the present specification calculates the contrast value of the image data as an evaluation index of the in-focus state, and uses the image data of the mode having the relatively maximum contrast value as a monitor. Display a movie.

DESCRIPTION OF SYMBOLS 1 Endoscope system 2 Endoscope 3 Processor apparatus 5 Monitor 20 Imaging device 21 Imaging optical system 22 Movable lens 23 Actuator 24 Imaging element 25 Endoscope control part 30 Image processing part 31 Processor control part 36 Evaluation value calculation part 50 Movable Lens holding member 52 SMA wire 60 Shaft member 61 Drive portion 65 Cam portion 66 Pin (follower)

Claims (7)

An endoscope system comprising: an endoscope having an image sensor; and a processor device that displays on a monitor image data acquired by the image sensor of the endoscope,
The endoscope includes at least one movable lens that is moved in an optical axis direction by an actuator, an optical system that changes a focal length and changes a depth of field by moving the movable lens, and a control And comprising
The control unit causes the actuator to repeatedly move the movable lens to each of a plurality of lens positions corresponding to a plurality of modes having different depths of field, and causes the image sensor to display an image at each lens position. Image sequentially,
The processor device evaluates the in-focus state for each mode based on the image data of each mode acquired by the endoscope, and causes the monitor to display a moving image of the image data of one mode having the highest evaluation. Endoscope system.   The endoscope system according to claim 1, wherein the depth of field of the optical system in two modes in which the position of the movable lens is adjacent among the plurality of modes partially overlaps.   The internal processing according to claim 1, wherein the processor device calculates a contrast value of the image data as an evaluation index of a focused state, and causes the monitor to display a moving image of the image data in a mode having a relatively maximum contrast value. Mirror system.   The endoscope system according to any one of claims 1 to 3, wherein the control unit of the endoscope changes an acquisition frequency of image data in each mode based on the evaluation by the processor device. . The endoscope is
A shaft member having a cam portion that is rotationally driven by the actuator around a rotation axis parallel to the optical axis of the optical system and circulates around the rotation axis;
A movable lens holding member that has a follower sliding on the cam portion and is moved back and forth along the shaft member as the shaft member rotates;
The endoscope system according to any one of claims 1 to 4, further comprising:   The focus state for each mode is evaluated based on the image data of each mode acquired by an endoscope that sequentially captures images of a plurality of modes with different depths of field, and the one with the highest evaluation Endoscopic image display method for displaying mode image data on monitor.   The endoscopic image display method according to claim 6, wherein a contrast value of the image data is calculated as an evaluation index of a focused state, and the image data in a mode having a relatively maximum contrast value is displayed as a moving image on a monitor.

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