Endoscope apparatus, control method of endoscope apparatus, and recording medium

1. An endoscope apparatus comprising:

an insertion portion;

an actuator configured to switch between a first optical path and a second optical path so that only one of a first subject image and a second subject image is imaged on an image forming area where the first subject image and the second subject image are commonly focused, the first subject image being an image of a subject formed by light emitted from a first objective optical system disposed at a distal end of the insertion portion, the second subject image being an image of the subject formed by light emitted from a second objective optical system disposed at the distal end of the insertion portion and having an optical magnification higher than that of the first objective optical system; and

a processor configured to:

receive instruction for zoom magnification;

perform a comparison of the zoom magnification instructed with the optical magnification of the second objective optical system;

control the actuator to switch to one of the first optical path so that the first subject image is formed on the image forming area and the second optical path so that the second subject image is formed on the image forming area, based on a result of the comparison of the zoom magnification with the optical magnification of the second objective optical system;

control an image sensor to acquire one of a first image based on the first subject image formed by the first optical path and a second image based on the second subject image formed by the second optical path; and

apply image processing to the one of the first image and the second image acquired by the image sensor.

2. The endoscope apparatus according to claim 1 ,

wherein the processor is configured to:

control the actuator to switch to the second optical path based on a result of the comparison being that the zoom magnification instructed is equal to or greater than the optical magnification of the second objective optical system; and

control the actuator to switch to the first optical path based on a result of the comparison being that the zoom magnification instructed is lower than the optical magnification of the second objective optical system.

3. The endoscope apparatus according to claim 2 ,

wherein the processor is configured to change parameters of the image processing based on the one of the first optical path and the second optical path being switched.

4. The endoscope apparatus according to claim 1 ,

wherein, in applying the image processing, the processor is configured to perform image processing of electronic zoom for enlarging the one of the first image and the second image acquired by the image sensor.

5. The endoscope apparatus according to claim 4 ,

wherein, in performing the image processing of the electronic zoom, the processor is configured to enlarge the one of the first image and the second image acquired by the image sensor based on the zoom magnification instructed.

6. The endoscope apparatus according to claim 5 ,

wherein, in performing the image processing of the electronic zoom, the processor is configured to change the electronic zoom magnification based on the zoom magnification instructed and the one of the first optical path and the second optical path being switched.

7. The endoscope apparatus according to claim 6 ,

wherein the processor is configured to:

set a magnification acquired by dividing the zoom magnification instructed by the optical magnification of the second objective optical system as the electronic zoom magnification based on a switch to the second optical path; and

set the zoom magnification instructed as the electronic zoom magnification based on a switch to the first optical path.

8. The endoscope apparatus according to claim 4 ,

wherein the processor is configured to set a center position of the second image as a center position of an enlarged image generated by the image processing of the electronic zoom.

9. The endoscope apparatus according to claim 4 ,

wherein the processor is configured to perform image processing of shading correction for correcting shading appearing in the one of the first image and the second image acquired by the image sensor.

10. The endoscope apparatus according to claim 9 ,

wherein, in the image processing of the shading correction, the processor is configured to correct each of shading appearing in the first image and shading appearing in the second image to be a common correction target value.

11. The endoscope apparatus according to claim 10 ,

wherein the processor is configured to switch a gain value for setting the common correction target value based on the one of the first optical path and the second optical path being switched.

12. The endoscope apparatus according to claim 4 ,

wherein the processor is configured to perform image processing of brightness correction for correcting an overall brightness of the one of the first image and the second image acquired by the image sensor.

13. The endoscope apparatus according to claim 12 ,

wherein, in the image processing for the brightness correction, the processor is configured to:

set a first area at a center portion of the one of the first image and the second image and a second area at a peripheral portion of the one of the first image and the second image, based on the zoom magnification; and

correct a brightness of the first area with high weighting and a brightness of the second area with low weighting.

14. The endoscope apparatus according to claim 13 ,

wherein the processor is configured to switch each weighting gain value corresponding to the first area and the second area based on the one of the first optical path and the second optical path being switched and the zoom magnification.

15. The endoscope apparatus according to claim 1 ,

wherein the processor is configured to output an optical path switching drive signal to the actuator when switching between the first optical path and the second optical path, and

wherein the actuator is configured to move a light shield that shields one of the first optical path and the second optical path by a magnetic field generated based on a polarity of a current in the optical path switching drive signal to shield the other of the first optical path and the second optical path.

16. The endoscope apparatus according to claim 1 ,

wherein the insertion portion comprises:

an elongated cord portion; and

an optical adapter detachably attached to a distal end side of the elongated scope portion,

wherein the first objective optical system, the second objective optical system, and the actuator are disposed within the optical adapter, and

wherein the image sensor is disposed on the distal end side of the elongated scope portion.

17. The endoscope apparatus according to claim 1 ,

wherein the processor is configured to control a display to provide notification of a switch to the first optical path and notification of a switch to the second optical path.

18. A control method of an endoscope apparatus, wherein the endoscope apparatus includes:

an insertion portion; and

an actuator configured to switch between a first optical path and a second optical path so that only one of a first subject image and a second subject image is imaged on an image forming area where the first subject image and the second subject image are commonly focused, the first subject image being an image of a subject formed by light emitted from a first objective optical system disposed at a distal end of the insertion portion, the second subject image being an image of the subject formed by light emitted from a second objective optical system disposed at the distal end of the insertion portion and having an optical magnification higher than that of the first objective optical system,

wherein the control method comprises:

receiving instruction for zoom magnification;

performing a comparison of the zoom magnification instructed with the optical magnification of the second objective optical system;

controlling the actuator to switch to one of the first optical path so that the first subject image is formed on the image forming area and the second optical path so that the second subject image is formed on the image forming area, based on a result of the comparison of the zoom magnification with the optical magnification of the second objective optical system;

controlling an image sensor to acquire one of a first image based on the first subject image formed by the first optical path and a second image based on the second subject image formed by the second optical path; and

applying image processing to the one of the first image and the second image acquired by the image sensor.

19. A non-transitory computer-readable recording medium storing a program for controlling an endoscope apparatus, wherein the endoscope apparatus includes:

an insertion portion; and

an actuator configured to switch between a first optical path and a second optical path so that only one of a first subject image and a second subject image is imaged on an image forming area where the first subject image and the second subject image are commonly focused, the first subject image being an image of a subject formed by light emitted from a first objective optical system disposed at a distal end of the insertion portion, the second subject image being an image of the subject formed by light emitted from a second objective optical system disposed at the distal end of the insertion portion and having an optical magnification higher than that of the first objective optical system,

wherein the program causes a computer to execute:

receiving instruction for zoom magnification;

performing a comparison of the zoom magnification instructed with the optical magnification of the second objective optical system;

controlling the actuator to switch to one of the first optical path so that the first subject image is formed on the image forming area and the second optical path so that the second subject image is formed on the image forming area, based on a result of the comparison of the zoom magnification with the optical magnification of the second objective optical system;

controlling an image sensor to acquire one of a first image based on the first subject image formed by the first optical path and a second image based on the second subject image formed by the second optical path; and

applying image processing to the one of the first image and the second image acquired by the image sensor.