Patent Application
20160374545
1. Field of the Invention
The present invention relates to an endoscope system, and more particularly to an endoscope system that radiates illuminating light in at least two directions and acquires a subject image from the at least two directions.
2. Description of the Related Art
Endoscopes are widely used in the medical field and industrial field. An endoscope includes illumination means and observation means on a distal end side of an insertion portion, and can be inserted into a subject to observe and inspect the inside of the subject.
In recent years, endoscopes that can observe two or more directions have been proposed. For example, as disclosed in Japanese Patent No. 4782900, an endoscope has been proposed which, in addition to a front field of view that takes the side to the front of the insertion portion as an observation field of view, also has a lateral field of view that takes the lateral face side of the insertion portion as an observation field of view. By using this kind of endoscope, the person performing the inspection can simultaneously observe two directions, i.e. the front direction and the lateral direction.
An endoscope system according to one aspect of the present invention includes: an insertion portion to be inserted inside a subject; an illuminating light emitting portion configured to emit a first illuminating light toward a front region inside the subject which includes a front direction of the insertion portion that is approximately parallel to a longitudinal direction of the insertion portion, and to emit a second illuminating light toward a lateral region in which at least one part is different from the front region inside the subject and which includes a lateral direction of the insertion portion that intersects with the longitudinal direction of the insertion portion; a first subject image acquisition portion which is provided in the insertion portion and is configured to acquire a first subject image from the front region; a second subject image acquisition portion which is provided in the insertion portion and is configured to acquire a second subject image from the lateral region; an image generation portion configured to generate a front observation image based on the first subject image and generate a lateral observation image based on the second subject image; a brightness comparison portion configured to compare a brightness of the front observation image and a brightness of the lateral observation image; a light amount adjustment portion configured to adjust an amount of the second illuminating light; and a drive portion configured to drive the light amount adjustment portion so that the lateral observation image becomes approximately a same brightness as the front observation image, based on a result of comparing the brightnesses obtained by the brightness comparison portion.
Hereunder, embodiments of the present invention are described with reference to the drawings.
The endoscope 2 includes an insertion portion 6 to be inserted into a subject, and an unshown operation portion, and is connected by unshown cables to the light source apparatus 3 and the processor 4. An illuminating window 7 and an observation window 8 for front observation, and two illuminating windows 9 and an observation window 10 for lateral observation are provided in a distal end portion 6a of the insertion portion 6 of the endoscope 2.
The distal end portion 6a of the insertion portion 6 has a distal end rigid member 11, and the illuminating window 7 is provided in a distal end face of the distal end rigid member 11. A distal end face of a light guide for front illumination 12 is arranged at the rear side of the illuminating window 7. The observation window 8 is provided in the distal end face of the distal end rigid member 11. An objective optical system 13 is arranged on the rear side of the observation window 8. An image pickup unit 14 is arranged on the rear side of the objective optical system 13. Note that a cover 11a is attached to the distal end portion of the distal end rigid member 11. Further, the insertion portion 6 is covered with an outer covering 11b.
Hence, illuminating light for the front is emitted from the illuminating window 7, and reflected light from the subject as an observation site inside the subject is incident on the observation window 8.
Two illuminating windows 9 are arranged in a side face of the distal end rigid member 11. A distal end face of a light guide for lateral illumination 16 is arranged to the rear of each illuminating window 9 through a mirror 15 whose reflective surface is a curved surface.
Hence, the illuminating window 7 and the plurality of illuminating windows 9 constitute an illuminating light emitting portion configured to emit, inside the subject, a first illuminating light in the front direction as a first direction and a second illuminating light in the lateral direction as a second direction that includes a direction that is different to the first direction.
The observation window 10 is arranged in the side face of the distal end rigid member 11. The objective optical system 13 is arranged on the rear side of the observation window 10. The objective optical system 13 is configured so as to direct reflected light from the front that passed through the observation window 8 and reflected light from the side that passed through the observation window 10 to the image pickup unit 14. In
That is, the observation window 8 constitutes a subject image acquisition portion that is provided in the insertion portion 6 and is configured to acquire an image from the front as a first direction, and the observation window 10 constitutes a subject image acquisition portion that is provided in the insertion portion 6 and is configured to acquire an image from the side as a second direction. The observation window 10 is disposed to the proximal end side of the insertion portion 6 with respect to the observation window 8.
More specifically, an image from the front as the first direction is a subject image from a front-view direction (first direction) that includes the front of the insertion portion 6 that is approximately parallel to the longitudinal direction of the insertion portion 6, that is, a subject image of a first region, and an image from the side as a second direction is a subject image from a side-view direction (second direction) that includes the sides of the insertion portion 6 that is a direction that intersects with the longitudinal direction of the insertion portion 6, that is, a subject image of a second region of the subject. Further, the observation window 8 is a front subject image acquisition portion configured to acquire a subject image of a first region inside the subject that includes the front of the insertion portion 6, and the observation window 10 is a lateral subject image acquisition portion configured to acquire a subject image of a second region inside the subject that includes the sides of the insertion portion 6.
The observation window 8 that is a subject image acquisition portion is disposed facing the direction in which the insertion portion 6 is to be inserted in the distal end portion 6a of the insertion portion 6. The observation window 10 that is a subject image acquisition portion is disposed facing an outer diameter direction of the insertion portion 6 in the distal end portion 6a of the insertion portion 6. The image pickup unit 14 that is an image pickup portion is disposed so as to photoelectrically convert a subject image from the observation window 8 and a subject image from the observation window 10 with the same image pickup surface, and is electrically connected to an image generation portion 40 of the processor 4 that is an image processing portion.
Hence, illuminating light for the front is emitted from the illuminating window 7 and reflected light from the subject passes through the observation window 8 and is incident on the image pickup unit 14, and illuminating light for the sides is emitted from the two illuminating windows 9 and reflected light from the subject passes through the observation window 10 and is incident on the image pickup unit 14. An image pickup device 14a of the image pickup unit 14 photoelectrically converts an optical image of the subject, and outputs an image pickup signal to the processor 4.
Returning to
An endoscopic image 21 displayed on a display screen 5a of the display apparatus 5 is an approximately rectangular image that has two regions 22 and 23. A circular region 22 at a center part is a region that displays a front observation image. The front observation image corresponds to a first image that corresponds to a subject image of a first region of the subject.
A C-shaped region 23 around the region 22 at the center part of the endoscopic image 21 is a region that displays a lateral observation image. The lateral observation image corresponds to a second image that corresponds to a subject image of a second region of the subject.
That is, the front observation image is displayed on the display screen 5a of the display apparatus 5 so as to be a substantially circular shape, and the lateral observation image is displayed on the display screen 5a of the display apparatus 5 so as to be an annular shape that surrounds at least part of the circumference of the front observation image. Hence, a wide-angle endoscopic image is displayed on the display apparatus 5.
Although this kind of image is realized by using a double reflection optical system that causes return light to be reflected twice with a side-view mirror lens, a configuration may also be adopted in which return light from a subject is reflected once by a single reflection optical system, and the reflected light is subjected to image processing by the processor 4 to align the orientations of a side-view field of view image and a direct-view field of view image.
Note that boundary regions of the first subject image and the second subject image may overlap or not overlap. In the case of a state in which the aforementioned boundary regions are overlapping, overlapping subject images may be acquired with the first subject image acquisition portion and the second subject image acquisition portion.
The light source apparatus 3 includes a light adjustment portion 31, a drive portion 32 that drives the light adjustment portion 31, and a light source 33.
The light adjustment portion 31 includes two polarization filters 31a and 31b and a diaphragm 31c. The configurations of the two polarization filters 31a and 31b are described later. The diaphragm 31c regulates an amount of light from the light source 33 based on a diaphragm control signal from a control portion 42.
In the light adjustment portion 31, the amount of light from the light source 33 is adjusted by the diaphragm 31c, and the two polarization filters 31a and 31b adjust the light amount so that the brightness of respective images displayed in the regions 22 and 23 becomes appropriate.
The two polarization filters 31a and 31b constitute a light amount adjustment portion configured to adjust a light amount of at least one of the first illuminating light that is emitted to the front and the second illuminating light that is emitted to the sides in order to adjust the brightness of the lateral observation image with respect to the front observation image. The plurality of polarization filters as an example of a light amount adjustment portion have, for example, respective portions that are disposed substantially collinearly so as to lie along the optical axis of the illuminating light.
Light emitted from the light adjustment portion 31 is condensed at a proximal end portion 34a of the light guide 34 by an unshown light condensing apparatus. The light emitted from the light adjustment portion 31 passes through the light guide 34 and is emitted from a distal end portion 34b of the light guide 34.
The light guide 34 includes the light guide for front illumination 12 and the light guide for lateral illumination 16 that are described above.
The incident surface 62 has two regions 63 and 64 that are light-receiving regions. An optical fiber group having end portions in the first region 63 is the light guide for front illumination 12. An optical fiber group having end portions in the second region 64 is the light guide for lateral illumination 16.
That is, the incident surface 62 of the proximal end portion 34a of the light guide 34 constitutes a light-receiving portion configured to receive illuminating light for illuminating the inside of the subject that is supplied from the light source 33, at the region 63 and the region 64 which are at a central part and a peripheral part, respectively, in the cross-sectional direction of the light guide 34. Further, the light guide 34 constitutes a light-guiding portion configured to guide light into the insertion portion 6 and emit illuminating light that is received at the region 63 at the central part in a first direction that is the front direction, and emit illuminating light that is received at the region 64 at the peripheral part in a second direction that is the lateral direction.
In
Note that a partition film may be provided so that light does not leak between the light guide for front illumination 12 and the light guide for lateral illumination 16.
Returning to
The light source 33 has a lamp that emits white light.
The processor 4 includes a photometry portion 41 and the control portion 42. The photometry portion 41 is a processing portion configured to calculate the respective brightnesses of the two regions 22 and 23 of the endoscopic image 21 that is described above, based on image data for an endoscopic image that is generated in the processor 4. The photometry portion 41 calculates the brightness of the region 22 and the brightness of the region 23, and outputs the calculated values to the control portion 42. The brightness of the respective regions is the average value of the luminance of all pixels inside the respective regions.
The respective configurations of the two polarization filters 31a and 31b of the light adjustment portion 31 will now be described.
The area R1 is circular, and the area R2 is a circular ring-shaped region around the area R1. In the case illustrated in
Rotating of the polarization filter 31b is performed by the drive portion 32 under control of the control portion 42.
The polarization filter 31a and polarization filter 31b are disposed on the same axis as the diaphragm 31c. The amount of light from the light source 33 is adjusted by the diaphragm 31c. Light that passed through the diaphragm 31c is transmitted through the polarization filter 31b and is incident on the polarization filter 31a, and light transmitted through the polarization filter 31a is incident on the incident surface 62 of the proximal end portion 34a of the light guide 34.
The light adjustment portion 31 is disposed with respect to the light guide 34 so that light emitted from the area R1 is transmitted through the polarization filter 31a and is incident on the first region 63 of the incident surface 62, and light emitted from the area R2 is transmitted through the polarization filter 31a and is incident on the second region 64 of the incident surface 62.
In this case, the outer diameters of the polarization filters 31a and 31b and the outer diameter of the incident surface 62 of the light guide 34 are equal, and the outer diameter of the area R1 of the polarization filter 31b and the outer diameter of the first region 63 of the incident surface 62 are equal.
The distribution ratio between the light amount that passes through the area R1 and is incident on the first region 63 of the light guide 34 and the light amount that passes through the area R2 and is incident on the second region 64 of the light guide 34 can be changed by rotating the polarization filter 31b within a range from 0 degrees to 90 degrees. That is, the two light amounts of the illumination for a front observation image and the illumination for a lateral observation image can be balanced by rotating the polarization filter 31b within a range from 0 degrees to 90 degrees relative to the polarization filter 31a. Further, the overall amount of illuminating light can be controlled by controlling the diaphragm 31c.
In this case, the rotational angle θ of the polarization filter 31b relative to the polarization filter 31a when the direction of the slits in the polarization filter 31a and the direction of the slits in the area R1 of the polarization filter 31b are parallel is taken as 0 degrees.
When the rotational angle is 0 degrees, as indicated by diagonal lines in
In the case illustrated in
When the rotational angle θ is 90 degrees, as indicated by diagonal lines in
When the rotational angle θ of the polarization filter 31b is changed within the range from 0 to 90 degrees, the distribution state between the light amounts incident on the first region 63 and the second region 64 of the light guide 34 changes.
When the rotational angle θ of the polarization filter 31b changes from 0 degrees toward 90 degrees, the light amount VL incident on the first region 63 of the light guide 34 gradually decreases as shown by a solid line ALc, and the light amount VL incident on the second region 64 of the light guide 34 gradually increases as shown by an alternate long and short dashed line ALs.
When the rotational angle θ of the polarization filter 31b is 0 degrees, as shown in
When the rotational angle θ of the polarization filter 31b is 45 degrees, the light amount VL that is incident on the first region 63 and the light amount VL that is incident on the second region 64 are each 0.5 (that is, 50% transmission).
Thus, by changing the rotational angle θ of the polarization filter 31b within the range from 0 to 90 degrees, the distribution between the two light amounts VL that are incident on the first region 63 and the second region 64 of the light guide 34 can be changed.
Next, operations of the processor 4 are described.
As described above, the photometry portion 41 calculates the brightness of the region 22 that displays the front observation image and the brightness of the region 23 that displays the lateral observation image in an endoscopic image, and outputs the calculated brightness values to the control portion 42. The control portion 42 compares a brightness La of the region 22 that displays the front observation image and a brightness Lb of the region 23 that displays the lateral observation image, and drives the drive portion 32 to rotate the polarization filter 31b so that the brightness La and the brightness Lb become equal. The overall brightness of the endoscopic image 21 is adjusted by the control portion 42 controlling the diaphragm 31c. That is, the control portion 42 controls the drive portion 32 so that the drive portion 32 drives the light adjustment portion 31 so that the brightnesses of the two images as photometry results from the photometry portion 41 become the same.
Hence, the control portion 42 constitutes a brightness comparison portion configured to compare the brightness of a first image that is a front observation image and a second image that is a lateral observation image.
The control portion 42, for example, compares the brightnesses La and Lb while monitoring the brightnesses, and when the brightness La is greater than the brightness Lb, drives the drive portion 32 in a range in which the rotational angle θ is from 45 degrees to 90 degrees, and when the brightness La is less than the brightness Lb, drives the drive portion 32 in a range in which the rotational angle θ is from 0 degrees to 45 degrees, so as to thus make the brightnesses La and Lb become equal. That is, rotational control of the polarization filter 31b is performed by feedback control so that the brightnesses La and Lb become equal.
In addition, even when the brightnesses La and Lb are equal, when the brightnesses are not a predetermined appropriate brightness L0, the brightness of the region 22 and the brightness of the region 23 in the endoscopic image can be controlled to become equal and the endoscopic image can be controlled to an appropriate brightness by controlling the diaphragm 31c.
In the conventional apparatus, as denoted by reference character F1, when only a side face of the distal end portion 6a is too close to a surface T of in-vivo tissue of the subject, as denoted by reference character G1, only the region 23 that displays a lateral observation image in the endoscopic image 21 is bright.
In contrast, according to the present embodiment that is described above, even when only the side face of the distal end portion 6a is too close to the surface T of in-vivo tissue of the subject as denoted by reference character F1, rotation of the polarization filter 31b of the light adjustment portion 31 is controlled and the distribution of the light amount that is incident on the first region 63 and the second region 64 of the light guide 34 is changed. As a result, as denoted by reference character G2, the brightness of the region 22 that displays the front observation image and the brightness of the region 23 that displays the lateral observation image in the endoscopic image 21 can be made equal.
According to the conventional apparatus, as denoted by reference character F2, when only the distal end face of the distal end portion 6a is too close to the surface T of in-vivo tissue of the subject, as denoted by reference character G3, only the region 22 that displays a front observation image in the endoscopic image 21 is bright.
In contrast, according to the present embodiment that is described above, even when only the distal end face of the distal end portion 6a is too close to the surface T of in-vivo tissue of the subject as denoted by reference character F2, rotation of the polarization filter 31b of the light adjustment portion 31 is controlled and the distribution of the light amount that is incident on the first region 63 and the second region 64 of the light guide 34 is changed. As a result, as denoted by reference character G4, the brightness of the region 22 that displays the front observation image and the brightness of the region 23 that displays the lateral observation image in the endoscopic image 21 can be made equal.
As described above, according to the endoscope apparatus of the present embodiment, each observation image that is obtained by an endoscope that is capable of observing in two directions can be made an appropriate brightness.
Although in the endoscope system of the first embodiment a single image pickup device picks up a subject image from both a front field of view and a lateral field of view, in the endoscope system of the present embodiment a plurality of, for example, three, image pickup devices are used, and the endoscope system is configured so that one image pickup device picks up a subject image of a front field of view, and two image pickup devices pick up subject images of two lateral fields of view, respectively, which are mutually different.
As shown in
An image pickup unit 14a for the first lateral field of view is arranged on the rear side of the observation window 10a inside the distal end portion 6a, and an image pickup unit 14b for the second lateral field of view is arranged on the rear side of the observation window 10b inside the distal end portion 6a. An image pickup unit 14c for the front field of view is arranged on the rear side of the observation window 8 for the front field of view. The observation windows 10a and 10b are disposed at substantially equal angles in the circumferential direction of the insertion portion 6.
The three image pickup units 14a, 14b and 14c each have an image pickup device and are controlled by the processor 4, and output image pickup signals to the processor 4.
That is, the observation window 8 constitutes a subject image acquisition portion which is disposed in the distal end portion 6a of the insertion portion 6 so as to face the direction in which the insertion portion 6 is to be inserted and which is configured to acquire an image from the front as a first direction, and the observation windows 10a and 10b constitute subject image acquisition portions disposed in a side face portion of the insertion portion 6 so as to face the outer diameter direction of the insertion portion 6 and which are configured to acquire images from the lateral direction as a second direction. The image pickup unit 14c is an image pickup portion configured to photoelectrically convert an image from the observation window 8. The image pickup units 14a and 14b are image pickup portions configured to photoelectrically convert two images from the observation windows 10a and 10b.
More specifically, an image from the front as the first direction is a subject image in a front-view direction (first direction), that is, a first region of the subject, that includes the front of the insertion portion 6 that is substantially parallel to the longitudinal direction of the insertion portion 6, and an image from the lateral direction as the second direction is a subject image in a side-view direction (second direction), that is, a second region of the subject, that includes the lateral direction of the insertion portion 6 that is a direction intersecting with the longitudinal direction of the insertion portion 6. Further, the observation window 8 is a front subject image acquisition portion configured to acquire a subject image of a first region inside the subject that includes the front of the insertion portion 6, and the observation windows 10a and 10b are lateral subject image acquisition portions configured to acquire a subject image of the second region inside the subject that includes the lateral direction of the insertion portion 6.
The observation window 8 that is a subject image acquisition portion is disposed in the distal end portion 6a of the insertion portion 6 so as to face the direction in which the insertion portion 6 is to be inserted, and the observation windows 10a and 10b that are subject image acquisition portions are disposed facing the outer diameter direction of the insertion portion 6 in the side face portion of the insertion portion 6. The image pickup units 14a and 14b that are image pickup portions are disposed so as to photoelectrically convert a subject image from the observation windows 10a and 10b, respectively, with an image pickup surface, and are electrically connected to the image generation portion 40 of the processor 4 that is an image processing portion. The image pickup unit 14c that is an image pickup portion is disposed so as to photoelectrically convert a subject image from the observation window 8 with an image pickup surface, and is electrically connected to the image generation portion 40 of the processor 4 that is an image processing portion.
Hence, illuminating light for the front is emitted from the illuminating window 7, and reflected light from the subject passes through the observation window 8 and is incident on the image pickup unit 14c, and illuminating light for the sides is emitted from the two illuminating windows 9a and 9b, and reflected light from the subject passes through the observation windows 10a and 10b and is incident on the image pickup units 14a and 14b. Each of the image pickup units 14a, 14b and 14c photoelectrically converts an optical image of the subject, and outputs an image pickup signal to the processor 4.
A processing circuit such as the image generation portion 40 in the processor 4 generates three endoscopic images based on three image pickup signals from the three image pickup units 14a, 14b and 14c, and outputs the endoscopic images to the display apparatus 5.
As shown in
As shown in
The processor 4 is an image processing portion configured to generate an image signal that includes a front observation image and two lateral observation images. The display apparatus 5 constitutes a display portion which is configured to receive the input of an image signal from the processor 4 and to display an endoscopic image including a front observation image and two lateral observation images so that the two lateral observation images are displayed adjacent to the front observation image. In this case, a configuration is adopted in which the processor 4 displays the two lateral observation images on the display apparatus 5 so as to sandwich the front observation image therebetween. Further, although in the present embodiment the display apparatus 5 displays a plurality of images, the present invention is not limited thereto.
For example,
The light adjustment portion 31A includes three polarization filters 31a, 81a and 81b as a light amount adjustment portion, and the diaphragm 31c. The configuration of the three polarization filters 31a, 81a and 81b is described later. The polarization filters 81a and 81b are rotationally controlled by the control portion 42.
The amount of light from the light source 33 is adjusted by the diaphragm 31c at the light adjustment portion 31A, and the balance of the light amount is adjusted by the three polarization filters 31a, 81a and 81b so that the brightnesses of the respective images displayed in the regions 71, 72 and 73 are appropriate. Light emitted from the light adjustment portion 31A is condensed in the proximal end portion 34a of the light guide 34A by an unshown light condensing apparatus. The light that is emitted from the light adjustment portion 31A passes through the light guide 34A, and is emitted from the distal end portion 34b of the light guide 34A.
The light guide 34A includes the light guide for front illumination 12, a first light guide for lateral illumination 16a and a second light guide for lateral illumination 16b.
The incident surface 62A has three regions 91, 92 and 93 that are light-receiving regions. An optical fiber group having end portions in the first region 91 is the second light guide for lateral illumination 16b. An optical fiber group having end portions in the second region 92 is the first light guide for lateral illumination 16a. An optical fiber group having end portions in the third region 93 is the light guide for front illumination 12.
In
Note that a partition film may be provided between the light guide for front illumination 12 and the light guide for lateral illumination 16a so that light does not leak, and may also be provided between the light guide for lateral illumination 16a and the light guide for lateral illumination 16b so that light does not leak therebetween.
The respective configurations of the two polarization filters 81a and 81b of the light adjustment portion 31A will now be described. As shown in
Rotating of the polarization filter 81a is performed by the drive portion 32 under control of the control portion 42.
Rotating of the polarization filter 81b is performed by the drive portion 32 under control of the control portion 42. Hence, the control portion 42 performs rotational control of the polarization filters 81a and 81b individually.
The polarization filters 31a, 81a and 81b are disposed on the same axis as the diaphragm 31c. The amount of light from the light source 33 is adjusted by the diaphragm 31c. Light that passed through the diaphragm 31c is transmitted through the polarization filter 81b and is incident on the polarization filter 81a, and light that is transmitted through the polarization filter 81a is incident on the polarization filter 31a and is then incident on the incident surface 62A of the proximal end portion 34a of the light guide 34.
As shown in
In addition, the outer diameter of the area R3 of the polarization filter 81a, the outer diameter of the area R6 of the polarization filter 81b, and the outer diameter of the region 92 of the incident surface 62A of the light guide 34 are equal. The outer diameter of the area R5 of the polarization filter 81b and the outer diameter of the region 91 of the incident surface 62A are equal.
The respective polarization filters 31a, 81a and 81b are disposed relative to the incident surface 62A of the light guide 34A so that light emitted from the area R4 of the polarization filter 81a passes through the polarization filter 31a and is incident on the third region 93 of the incident surface 62A.
The respective polarization filters 31a, 81a and 81b are disposed relative to the incident surface 62A of the light guide 34A so that light emitted from the area R6 of the polarization filter 81b passes through the area R3 of the polarization filter 81a and further passes through the polarization filter 31a and is incident on the second region 92 of the incident surface 62A.
The respective polarization filters 31a, 81a and 81b are disposed relative to the incident surface 62A of the light guide 34A so that light emitted from the area R5 of the polarization filter 81b passes through the area R3 of the polarization filter 81a and further passes through the polarization filter 31a and is incident on the first region 91 of the incident surface 62A.
By rotating the polarization filter 81a within a range from 0 degrees to 90 degrees relative to the polarization filter 31a, the illumination for a front observation image and the entire light amount of illumination for lateral observation images can be balanced.
In addition, the illumination for a front observation image and the entire light amount of illumination for a lateral observation image are balanced, the illumination for a first lateral observation image and the illumination for a second lateral observation image can be balanced by rotating the polarization filter 81b within a range from 0 degrees to 90 degrees relative to the polarization filter 81a.
In this case, the rotational angle θ1 of the polarization filter 81a with respect to the polarization filter 31a when the direction of the slits in the polarization filter 31a and the direction of the slits in the area R4 of the polarization filter 81a are parallel is taken as 0 degrees.
When the rotational angle θ1 of the polarization filter 81a with respect to the polarization filter 31a changes from 0 degrees toward 90 degrees, the light amount VL incident on the region 93 of the light guide 34 gradually decreases as shown by a solid line ALc, and the light amount VL incident on the two regions 91 and 92 of the light guide 34 gradually increases as shown by an alternate long and short dashed line ALs.
When the rotational angle θ1 of the polarization filter 81a is 0 degrees, as shown in
When the rotational angle θ1 of the polarization filter 81a is 45 degrees, the light amount VL incident on the region 93 and the light amount VL incident on the regions 91 and 92 are each 0.5 (that is, 50% transmission).
Thus, by changing the rotational angle θ1 of the polarization filter 81a within the range from 0 to 90 degrees, the distribution between the light amount incident on the region 93 and the light amount incident on the two regions 91 and 92 of the light guide 34 can be changed.
In this case, the rotational angle θ2 of the polarization filter 81b with respect to the polarization filter 81a when the direction of the slits in the area R3 of the polarization filter 81a and the direction of the slits in the area R6 of the polarization filter 81b are parallel is taken as 0 degrees.
When the rotational angle θ2 of the polarization filter 81b with respect to the polarization filter 81a changes from 0 degrees toward 90 degrees, the light amount VL incident on the region 92 of the light guide 34 gradually decreases as shown by an alternate long and short dashed line ALsb, and the light amount VL incident on the region 91 the light guide 34 gradually increases as shown by, a solid line ALsa.
When the rotational angle θ2 of the polarization filter 81b with respect to the polarization filter 81a is 0 degrees, as shown in
When the rotational angle θ2 of the polarization filter 81b is 45 degrees, the light amount incident on the region 92 and the light amount incident on the region 91 are each 0.5 (that is, 50% transmission).
Thus, by changing the rotational angle θ2 of the polarization filter 81b within the range from 0 to 90 degrees, the distribution between the light amount incident on the region 92 and the light amount incident on the region 91 of the light guide 34 can be changed.
Next, operations of the processor 4 are described.
As described above, the photometry portion 41A calculates brightnesses La1, La21, La22 of the respective images of the regions 71, 72 and 73 in an endoscopic image, and outputs the calculated brightness values to the control portion 42. The brightnesses of the respective regions are average values of the luminance of all pixels within the respective regions. The control portion 42 as a brightness comparison portion drives the drive portion 32 to rotate the polarization filter 81a so that the brightness La1 of the image of the region 72 that displays a front observation image and a brightness La2 (average value of the brightnesses La21 and La22) of the two images of the region 71 that displays a first lateral observation image and the region 73 that displays a second lateral observation image becomes equal.
Rotational control of the polarization filter 81a is performed by feedback control that, for example, while monitoring the brightnesses La1 and La2, drives the drive portion 32 within a range in which the rotational angle θ1 is from 45 degrees to 90 degrees when the brightness La1 is greater than the brightness La2, and drives the drive portion 32 within a range in which the rotational angle θ1 is from 0 degrees to 45 degrees when the brightness La1 is less than the brightness La2, so that the brightnesses La1 and La2 thus become equal.
In addition, after the brightnesses La1 and La2 become equal, the control portion 42 drives the drive portion 32 to rotate the polarization filter 81b so that the brightness La21 of the image of the region 71 and the brightness La22 of the image of the region 73 become equal.
Rotational control of the polarization filter 81b is performed by feedback control that, for example, while monitoring the brightnesses La21 and La22, drives the drive portion 32 within a range in which the rotational angle θ2 is from 0 degrees to 45 degrees when the brightness La21 is greater than the brightness La22, and drives the drive portion 32 within a range in which the rotational angle θ2 is from 45 degrees to 90 degrees when the brightness La21 is less than the brightness La22, so that the brightnesses La21 and La22 thus become equal.
As described in the foregoing, according to the endoscope apparatus of the present embodiment, each observation image obtained by an endoscope that is capable of observing in three directions can be made an appropriate brightness.
A modification of the configuration of the three polarization filters in the endoscope apparatus that is capable of observing in three directions of the second embodiment will now be described.
Although in the above described second embodiment, slits are provided over the entire region of each polarization filter, in the present modification a region in which slits are not formed at one part is provided in one polarization filter.
In this case, the rotational angle θ3 of the polarization filter 81a1 with respect to the polarization filter 31a when the direction of the slits in the area R4 of the polarization filter 31a and the direction of the slits in the area R4 of the polarization filter 81a1 are parallel is taken as 0 degrees.
When the rotational angle θ3 of the polarization filter 81a1 with respect to the polarization filter 31a changes from 0 degrees toward 90 degrees, the light amount VL incident on the region 93 of the light guide 34A gradually decreases as shown by a solid line ALc.
When the rotational angle θ3 of the polarization filter 81a1 is 0 degrees, as shown in
When the rotational angle θ3 of the polarization filter 81a1 is 45 degrees, light amount VL incident on the region 93 is 0.5 (that is, 50% transmission).
Thus, by changing the rotational angle θ3 of the polarization filter 81a1 within the range from 0 to 90 degrees, the light amount incident on the region 93 of the light guide 34A can be changed.
In this case, the rotational angle θ4 of the polarization filter 81b with respect to the polarization filter 31a when the direction of the slits in the area R0 of the polarization filter 31a and the direction of the slits in the area R6 of the polarization filter 81b are orthogonal is taken as 0 degrees.
When the rotational angle θ4 of the polarization filter 81b with respect to the polarization filter 31a changes from 0 degrees toward 90 degrees, the light amount VL incident on the region 92 of the light guide 34A gradually increases as shown by a solid line ALsb and the light amount VL incident on the region 91 of the light guide 34A gradually decreases as shown by an alternate long and short dashed line ALsa.
When the rotational angle θ4 of the polarization filter 81b with respect to the polarization filter 31a is 0 degrees, as shown in
When the rotational angle θ4 of the polarization filter 81b is 45 degrees, the light amount VL that is incident on the region 92 and the light amount VL that is incident on the region 91 are each 0.5 (that is, 50% transmission).
Thus, by changing the rotational angle θ4 of the polarization filter 81b with respect to the polarization filter 31a within the range from 0 to 90 degrees, the distribution between the light amount incident on the region 92 and the light amount incident on the region 91 of the light guide 34A can be changed.
In the present modification, the control portion 42a light amount for front illumination is adjusted by controlling the rotational angle θ3 of the polarization filter 81a1 in accordance with the brightness of an image of the region 72, and the balance between the brightness of an image of the region 71 and the brightness of an image of the region 73 can be adjusted by controlling the rotational angle θ4 of the polarization filter 81b.
As described in the foregoing, by means of the endoscope apparatus of the modification of the present embodiment also, each observation image obtained by an endoscope that is capable of observing in three directions can be made an appropriate brightness.
Although an endoscope system of the present embodiment is, similarly to the second embodiment, also a system in which three image pickup devices are used and which is configured to receive a subject image of one front field of view and subject images of two lateral fields of view, the endoscope system of the present embodiment has a different configuration to the second embodiment.
In the endoscope system of the present embodiment, the configuration of a light adjustment portion is different to the second embodiment.
As shown in
The incident surface 62A has three regions 101, 102 and 103 that are light-receiving regions. An optical fiber group having end portions in the first region 101 is the light guide for front illumination 12. An optical fiber group having end portions in the second region 102 is the first light guide for lateral illumination 16a. An optical fiber group having end portions in the third region 103 is the second light guide for lateral illumination 16b.
The plurality of polarization filters as an example of a light amount adjustment portion have, for example, respective portions that are disposed substantially collinearly so as to lie along the optical axis of the illuminating light.
In
Note that a partition film may be provided between the light guide for front illumination 12 and the light guide for lateral illumination 16a so that light does not leak, and may also be provided between the light guide for lateral illumination 16a and the light guide for lateral illumination 16b so that light does not leak.
The respective configurations of the two polarization filters 31a and 100 of the light adjustment portion 31B will now be described. As shown in
The polarization filter 100 has a circular area R7 at a center part, and has two semicircular areas R71 and R72 inside the area R7. Slits in a diagonal direction that have the same width as the slits of the polarization filter 31a are provided in the areas R71 and R72. The area R7 has the two regions 71 and 72 in which the direction of the slits (that is, the polarization direction) in the area R71 and the direction of the slits (the polarization direction) of the area R72 are orthogonal to each other. The direction of the slits in the area R71 and the direction of the slits in the area R72 are each at an angle of 45 degrees with respect to the direction of the slits of the polarization filter 31a.
Crosswise slits having the same width as the slits of the polarization filter 31a are provided in the circular ring-shaped area R8 around the central circular area R7. Lengthwise slits having the same width as the slits of the polarization filter 31a are provided in the circular ring-shaped area R9 around the circular ring-shaped area R8. The circular polarization filter 100 is disposed so as to be rotatable around the central axis of the circle. In the case of the state illustrated in
Rotating of the polarization filter 100 is performed by the drive portion 32 under control of the control portion 42.
The polarization filter 31a and the polarization filter 100 are disposed on the same axis as the diaphragm 31c. The amount of light from the light source 33 is adjusted by the diaphragm 31c. Light that passed through the diaphragm 31c is transmitted through the polarization filter 100 and is incident on the polarization filter 31a, and is thereafter incident on the incident surface 62A of the proximal end portion 34a of the light guide 34B.
As shown in
In addition, the outer diameter of the area R7 of the polarization filter 100 and the outer diameter of the region 101 of the incident surface 62A of the light guide 34B are equal.
The polarization filter 31a and the polarization filter 100 are disposed with respect to the incident surface 62A of the light guide 34B so that light emitted from the area R9 of the polarization filter 100 is transmitted through the polarization filter 31a and is incident on the third region 103 of the incident surface 62A.
The polarization filter 31a and the polarization filter 100 are disposed with respect to the incident surface 62A of the light guide 34B so that light emitted from the area R8 of the polarization filter 100 is transmitted through the polarization filter 31a and is incident on the second region 102 of the incident surface 62A.
The polarization filter 31a and the polarization filter 100 are disposed with respect to the incident surface 62A of the light guide 34B so that light emitted from the area R7 of the polarization filter 100 is transmitted through the polarization filter 31a and is incident on the region 101 of the incident surface 62A.
By rotating the polarization filter 100 within a range of 0 degrees to 90 degrees relative to the polarization filter 31a, the two amounts of illumination light for a lateral observation image can be balanced while keeping the light amount of the illumination for a front observation image constant.
In this case, the rotational angle θ5 of the polarization filter 100 with respect to the polarization filter 31a when the direction of the slits in the area R0 of the polarization filter 31a and the direction of the slits in the area R8 of the polarization filter 100 are orthogonal is taken as 0 degrees.
When the rotational angle θ5 of the polarization filter 100 with respect to the polarization filter 31a changes from 0 degrees toward 90 degrees, the light amount VL incident on the region 101 of the light guide 34B is constant as shown by a solid line ALc. This is because the directions of the slits of the areas R71 and R72 are orthogonal to each other.
When the rotational angle θ5 of the polarization filter 100 with respect to the polarization filter 31a changes from 0 degrees toward 90 degrees, the light amount VL incident on the region 102 of the light guide 34B gradually increases as shown by a solid line ALsa, and the light amount VL incident on the region 103 of the light guide 34B gradually decreases as shown by an alternate long and short dashed line ALsb.
When the rotational angle θ5 of the polarization filter 100 with respect to the polarization filter 31a is 0 degrees, as shown in
When the rotational angle θ5 of the polarization filter 100 is 45 degrees, the light amount VL that is incident on the region 102 and the light amount VL that is incident on the region 103 are each 0.5 (that is, 50% transmission).
Thus, by changing the rotational angle θ5 of the polarization filter 100 with respect to the polarization filter 31a within the range from 0 to 90 degrees, the distribution between the light amount incident on the region 102 and the light amount incident on the region 103 of the light guide 34B can be changed.
As described in the foregoing, by means of the endoscope apparatus of the present embodiment also, each observation image obtained by an endoscope that is capable of observing in three directions can be made an appropriate brightness.
A modification of the configuration of two polarization filters in the endoscope apparatus capable of observing three directions of the third embodiment will now be described.
Although in the above described third embodiment the incident surface 62A of the light guide 34B has a semicircular region and a circular ring-shaped region, in the present modification the circular incident surface 62A of the light guide 34B has a layer-like region 104 at the center and has two regions 105 and 106 which are formed in a manner that sandwiches the region 104 therebetween.
Slits in a diagonal direction that have the same width as slits of the polarization filter 31a are provided in the areas R111 and R112. The direction of the slits in the area R111 and the direction of the slits in the area R112 are orthogonal to each other. In the case of the state shown in
The circular polarization filter 31a is disposed so as to be rotatable around the central axis of the circle, and the polarization filter 100a is fixed with respect to the light guide 34B and does not rotate. In the case of the state illustrated in
In the layer-like area R13 on the lower side in
The respective polarization filters 31a and 100a are disposed with respect to the incident surface 62A of the light guide 34B so that light emitted from the area R11 of the polarization filter 100a passes through the polarization filter 31a and is incident on the region 104 of the incident surface 62A.
The respective polarization filters 31a and 100a are disposed with respect to the incident surface 62A of the light guide 34B so that light emitted from the area R13 of the polarization filter 100a passes through the polarization filter 31a and is incident on the region 105 of the incident surface 62A.
Likewise, the respective polarization filters 31a and 100a are disposed with respect to the incident surface 62A of the light guide 34B so that light emitted from the area R14 of the polarization filter 100a passes through the polarization filter 31a and is incident on the region 106 of the incident surface 62A.
An optical fiber group having end portions in the first region 104 is an end face of the light guide for front illumination 12. An optical fiber group having end portions in the second region 105 is the first light guide for lateral illumination 16a, and an optical fiber group having end portions in the third region 105 is the second light guide for lateral illumination 16b.
Rotating of the polarization filter 31a is performed by the drive portion 32 under control of the control portion 42.
Even if the polarization filter 31a rotates, a light amount VL that is incident on the region 104 of the light guide 34B is constant. This is because the directions of the slits of the areas R111 and R112 are orthogonal to each other.
When a rotational angle θ6 of the polarization filter 31a with respect to the polarization filter 100s changes from 0 degrees toward 90 degrees, as shown in
Hence, by means of the endoscope apparatus of the modification of the present embodiment also, each observation image obtained by an endoscope that is capable of observing in three directions can be made an appropriate brightness.
An endoscope system of the present embodiment is an endoscope system that can reduce illuminating light in only a region in which halation occurred in an endoscopic image.
As shown in
A light adjustment portion 31C includes the polarization filter 111, the polarization filter 112 and the diaphragm 31c.
The plurality of polarization filters as an example of a light amount adjustment portion have, for example, respective portions that are disposed substantially collinearly so as to lie along the optical axis of the illuminating light.
The proximal end portion 34a of the light guide 34C is divided into four regions so that the areas are equal around the central axis of the light guide 34C. In
That is, at the proximal end portion 34a of the light guide 34C, the region 124 for right side illumination and the region 122 for left side illumination are disposed on opposing sides on the incident surface 62A, and the region 123 for upward illumination and the region 121 for front illumination are disposed on opposing sides on the incident surface 62A.
The circular polarization filter 111 is divided into two parts by a straight line that passes through the center of the circular polarization filter 111, and has two semicircular areas R21 and R22. The areas R21 and R22 have slits that are provided in directions that are orthogonal to each other.
The circular polarization filter 112 is divided into four parts by lines that pass through the center of the circular polarization filter 112, and slits having the same width as the slits of the polarization filter 111 are provided in one quadrantal area R23 among the four parts. Slits are not formed in an area R24 that is other than the area R23 of the polarization filter 112. The shape and size of the area R23 matches the shape and size of the each of the four regions 121, 122, 123 and 124.
As shown in
The polarization filter 112 is rotatable with respect to the polarization filter 111.
In this case, a rotational angle θ7 of the polarization filter 112 with respect to the polarization filter 111 when the area R23 of the polarization filter 112 matches the region 124 of the incident surface 62A of the light guide 34C, that is, when light from the area R23 passes through the polarization filter 111 and is incident on only the region 124, is taken as 0 degrees.
For example, it is shown that when the rotational angle θ7 of the polarization filter 112 with respect to the polarization filter 111 is 0 degrees, although 100% of light is incident on the regions 121, 122 and 123, 50% of light is incident on the region 124 for right side illumination. In
Further, it is shown that when the rotational angle θ7 is 45 degrees, although 100% of light is incident on the regions 121 and 122, 50% of light is incident on the region 123 for upward illumination and the region 124 for right side illumination. In
Likewise,
A middle row section in
When the insertion portion 6 is inserted into a subject and the distal end portion 6a of the insertion portion 6 is close to an inner wall inside the subject, a region in a direction that is too close to the inner wall appears as a halation region in the endoscopic image.
For example, when the right side of the distal end portion 6a is too close to an inner wall, a region on the right side of the endoscopic image appears as a halation region. Further, when an upper part of the distal end portion 6a is too close to an inner wall, a region on an upper side of the endoscopic image appears as a halation region. In addition, when the front of the distal end portion 6a is too close to an inner wall, a region on the front side of the endoscopic image appears as a halation region.
The control portion 42 can determine which region of an endoscopic image halation occurs in based on the luminance value of each pixel in the respective regions of the endoscopic image.
Therefore, when the control portion 42 detects a halation region, the control portion 42 rotates the polarization filter 112 so as to decrease the amount of illuminating light which illuminates the relevant region. As a result, a halation region can be eliminated from the endoscopic image. That is, the drive portion 32 controls the drive portion 32 so as to drive the light adjustment portion 31C so that halation as a photometry result from the photometry portion 41 is reduced.
When the angle θ7 in
For example, when the distal end portion 6a of the insertion portion 6 is too close to the inner wall T on the right side inside the subject, a region on the right side of the endoscopic image appears as a halation region. The control portion 42 can detect that the region in which halation is occurring is the region on the right side based on the brightness of each region of the endoscopic image. In such a case, in
However, when the control portion 42 controls the drive portion 32 so as to make the angle θ7 of the polarization filter 112 with respect to the polarization filter 111 0 degrees, as shown in the middle row for a time when the angle θ7 is 0 degrees in
Further, similarly, for example, when the distal end portion 6a of the insertion portion 6 is too close to the inner wall T on the upper side inside the subject, although the region on the upper side of the endoscopic image becomes a halation region, in this case, when the control portion 42 controls the drive portion 32 to make the angle θ7 of the polarization filter 112 with respect to the polarization filter 111 90 degrees, in
Similarly, when halation is detected in other regions including also the front region, the halation region in the endoscopic image can be eliminated or the halation can be suppressed to a certain extent by controlling the rotational angle θ7 of the polarization filter 112.
As described above, according to the endoscope system of the present embodiment, the illuminating light of only a region in which halation has occurred in an endoscopic image can be decreased to thereby eliminate or suppress the occurrence of halation in the endoscopic image.
An endoscope system of the present embodiment is an endoscope system that can adjust light amounts of front illumination and illumination in three lateral directions.
As shown in
The light adjustment portion 31D includes the polarization filter 31a and the two polarization filters 113 and 114 as a light amount adjustment portion and the diaphragm 31c.
The plurality of polarization filters as an example of a light amount adjustment portion have, for example, respective portions that are disposed substantially collinearly so as to lie along the optical axis of the illuminating light.
The incident surface 62A has four regions 131, 132, 133 and 134 that are light-receiving regions. An optical fiber group having end portions in the first region 131 is a third light guide for lateral illumination 16c. An optical fiber group having end portions in the second region 132 is the second light guide for lateral illumination 16b. An optical fiber group having end portions in the third region 133 is the first light guide for lateral illumination 16a. An optical fiber group having end portions in the fourth region 134 is the light guide for front illumination 12.
In
Note that a partition film may be provided between the light guide for front illumination 12 and the light guide for lateral illumination 16a, between the light guide for lateral illumination 16a and the light guide for lateral illumination 16b, and between the light guide for lateral illumination 16b and the light guide for lateral illumination 16c so that light does not leak between the aforementioned light guides.
The polarization filter 113 has a central circular area R31 and a circular ring-shaped area R32 around the area R31. Slits having the same width as the slits of the polarization filter 31a are provided in the areas R31 and R32. The direction of the slits in the area R31 and the direction of the slits in the area R32 are orthogonal.
The polarization filter 114 has a central circular area R33, a circular ring-shaped area R34 provided around the area R33, and a circular ring-shaped area R35 provided around the area R34. Slits having the same width as the slits of the polarization filter 31a are provided in the areas R33, R34 and R35. The direction of the slits in the area R34 and the direction of the slits in the area R35 are orthogonal. The direction of the slits in the area R33 is at an angle of 45 degrees with respect to the direction of the slits in the areas R34 and R35.
As shown in
Further, the outer diameter of the area R34 of the polarization filter 114 and the outer diameter of the region 132 of the incident surface 62A are equal. Furthermore, the outer diameter of the area R33 of the polarization filter 114 and the outer diameter of the region 131 of the incident surface 62A are equal.
The respective polarization filters 31a, 121 and 122 are disposed with respect to the incident surface 62A of the light guide 34D so that light emitted from the area R32 of the polarization filter 113 is transmitted through the polarization filter 31a and is incident on the fourth region 134 of the incident surface 62A.
The respective polarization filters 31a, 121 and 122 are disposed with respect to the incident surface 62A of the light guide 34D so that light emitted from the area R35 of the polarization filter 114 is transmitted through the area R31 of the polarization filter 113 and, furthermore, is transmitted through the polarization filter 31a to be incident on the third region 133 of the incident surface 62A.
The respective polarization filters 31a, 121 and 122 are disposed with respect to the incident surface 62A of the light guide 34D so that light emitted from the area R34 of the polarization filter 114 is transmitted through the area R31 of the polarization filter 113 and, furthermore, is transmitted through the polarization filter 31a to be incident on the second region 132 of the incident surface 62A.
The respective polarization filters 31a, 121 and 122 are disposed with respect to the incident surface 62A of the light guide 34D so that light emitted from the area R33 of the polarization filter 114 is transmitted through the area R31 of the polarization filter 113 and, furthermore, is transmitted through the polarization filter 31a to be incident on the first region 131 of the incident surface 62A.
By rotating the polarization filter 113 within a range of 0 degrees to 90 degrees relative to the polarization filter 31a, the amount of illumination light for a front observation image and the three amounts of illumination light for a lateral observation image can be balanced.
In addition, after the illumination for a front observation image and the three amounts of illumination light for a lateral observation image are balanced, the illumination for a first lateral observation image, the illumination for a second lateral observation image, and the illumination for a third lateral observation image can be balanced by rotating the polarization filter 114 within a range from −90 degrees to 90 degrees relative to the polarization filter 113.
Four endoscopic images are displayed on the display screen 5a of the display apparatus 5. A circular first region 140 in the center is a region that displays a front observation image which is generated based on an image pickup signal from the image pickup unit 14c. A second region 141 that is to the left of the first region 140 is a region that displays a first lateral observation image which is generated based on an image pickup signal from the image pickup unit 14a. A third region 142 on the upper side of the first region 140 is a region that displays a second lateral observation image which is generated based on an image pickup signal from the image pickup unit 14a. A fourth region 143 that is to the right of the first region 140 is a region that displays a third lateral observation image which is generated based on an image pickup signal from the image pickup unit 14a.
As shown in
In this case, the rotational angle θ8 of the polarization filter 113 with respect to the polarization filter 31a when the direction of the slits of the polarization filter 31a and the direction of the slits of the area R32 of the polarization filter 113 are parallel is taken as 0 degrees.
When the rotational angle θ8 of the polarization filter 113 with respect to the polarization filter 31a changes from 0 degrees toward 90 degrees, the light amount VL incident on the region 134 of the light guide 34D gradually decreases as shown by a solid line ALc, and the light amount VL incident on the regions 131, 132 and 133 of the light guide 34D gradually increases as shown by an alternate long and short dashed line ALs.
When the rotational angle θ8 of the polarization filter 113 is 0 degrees, as shown in
When the rotational angle θ8 of the polarization filter 113 is 45 degrees, the light amount VL that is incident on the region 134 and the light amount VL that is incident on the regions 131, 132 and 133 are each 0.5 (that is, 50% transmission).
Thus, by changing the rotational angle θ8 of the polarization filter 113 within the range from 0 to 90 degrees, the distribution between the light amount incident on the region 134 and the light amount incident on the three regions 131, 132 and 133 can be changed.
In this case, the rotational angle θ9 of the polarization filter 114 with respect to the polarization filter 113 when the direction of the slits of the area R32 of the polarization filter 113 and the direction of the slits of the area R35 of the polarization filter 114 are parallel is taken as 0 degrees.
When the rotational angle θ9 of the polarization filter 114 with respect to the polarization filter 113 changes from 0 degrees toward 90 degrees, and when the rotational angle θ9 changes from 0 degrees toward −90 degrees, the light amount VL incident on the region 133 of the light guide 34D gradually increases as shown by an alternate long and short dashed line ALsa, and the light amount VL incident on the region 132 of the light guide 34D gradually decreases as shown by a solid line ALsb.
Further, when the rotational angle θ9 of the polarization filter 114 with respect to the polarization filter 113 changes from 0 degrees toward 90 degrees, the light amount VL that is incident on the region 131 of the light guide 34D gradually decreases and thereafter increases as shown by a chain double-dashed line ALsc. When the rotational angle θ9 of the polarization filter 114 with respect to the polarization filter 113 changes from 0 degrees toward −90 degrees, the light amount VL that is incident on the region 131 of the light guide 34D gradually decreases and thereafter increases as shown by a chain double-dashed line ALsc.
When the rotational angle θ9 of the polarization filter 114 with respect to the polarization filter 113 is 45 degrees or −45 degrees, as shown in
Thus, by changing the rotational angle θ9 of the polarization filter 114 within a range from −90 degrees to 90 degrees, the distribution of a light amount incident on the regions 131, 132 and 133 of the light guide 34D can be changed.
Next, operations of the processor 4 are described.
As described above, the photometry portion 41 calculates the brightness of the respective images of the regions 140, 141, 142 and 143 in an endoscopic image, and outputs the calculated brightness values to the control portion 42. The brightness of each region is an average value of the luminance of all pixels within the relevant region. The control portion 42 drives the drive portion 32 to rotate the polarization filter 113 so that a brightness La1 of an image of the region 140 that displays a front observation image and the brightness Las of images of the other three regions 141, 142 and 143 become equal.
Rotational control of the polarization filter 113 is performed by feedback control that, for example, while monitoring the brightness La1 and brightness Las, drives the drive portion 32 within a range in which the rotational angle θ8 is from 45 degrees to 90 degrees when the brightness La1 is greater than the brightness Las, and drives the drive portion 32 within a range in which the rotational angle θ8 is from 0 degrees to 45 degrees when the brightness La1 is less than the brightness Las, so that the brightness La1 and brightness Las become equal.
In addition, after the brightness La1 and brightness Las become equal, the control portion 42 drives the drive portion 32 to rotate the polarization filter 114 so that the brightnesses of the images of the three regions 141, 142 and 143 become equal.
Rotational control of the polarization filter 114 is performed by feedback control that, for example, while monitoring the brightnesses of the three regions 141, 142 and 143, drives the drive portion 32 within a range in which the rotational angle θ9 is from −90 degrees to 90 degrees so that the brightnesses of the three regions 141, 142 and 143 become equal.
As described above, according to the endoscope apparatus of the present embodiment, each observation image obtained by an endoscope that is capable of observing in four directions can be made an appropriate brightness.
An endoscope system of the present embodiment is an endoscope system that can adjust illumination light amounts for four directions.
As shown in
A light adjustment portion 31E includes the polarization filter 31a and four polarization filters 141, 142, 143 and 144, and the diaphragm 31c.
The plurality of polarization filters as an example of a light amount adjustment portion have, for example, respective portions that are disposed substantially collinearly so as to lie along the optical axis of the illuminating light.
The drive portion 32 can individually rotate each of the four polarization filters 141, 142, 143 and 144 as a light amount adjustment portion independently from each other.
The polarization filter 141 has a central circular area R41, and a circular ring-shaped area R42 around the area R41. Slits having the same width as the slits of the polarization filter 31a are provided in the area R42. The area R41 does not have slits, and is a region that transmits incident light as it is. That is, only the area R42 is a polarization filter region.
The polarization filter 142 has a central circular area R43, and a circular ring-shaped area R44 around the area R43. Slits having the same width as the slits of the polarization filter 31a are provided in the area R44. The area R43 does not have slits, and is a region that transmits incident light as it is. That is, only the area R44 is a polarization filter region.
The polarization filter 143 has a central circular area R45, and a circular ring-shaped area R46 around the area R45. Slits having the same width as the slits of the polarization filter 31a are provided in the area R46. The area R45 does not have slits, and is a region that transmits incident light as it is. That is, only the area R46 is a polarization filter region.
The polarization filter 144 has a circular area R47 in which slits having the same width as the slits of the polarization filter 31a are provided.
As shown in
In addition, the outer diameter of the area R46 of the polarization filter 143, the inner diameter of the area R44 of the polarization filter 142 and the outer diameter of the region 132 of the incident surface 62A are equal.
Further, the outer diameter of the area R47 of the polarization filter 144, the inner diameter of the area R46 of the polarization filter 143 and the outer diameter of the region 131 of the incident surface 62A are equal.
The respective polarization filters 31a and 141 are disposed with respect to the incident surface 62A of the light guide 34D so that light emitted from the area R42 of the polarization filter 141 passes through the polarization filter 31a and is incident on the fourth region 134 of the incident surface 62A.
The respective polarization filters 31a, 141 and 142 are disposed with respect to the incident surface 62A of the light guide 34D so that light emitted from the area R44 of the polarization filter 142 passes through the area R41 of the polarization filter 141 and also passes through the polarization filter 31a and is incident on the third region 133 of the incident surface 62A.
The respective polarization filters 31a, 141, 142 and 143 are disposed with respect to the incident surface 62A of the light guide 34D so that light emitted from the area R46 of the polarization filter 143 passes through the area R43 of the polarization filter 142, passes through the area R41 of the polarization filter 141 and, further, passes through the polarization filter 31a and is incident on the second region 132 of the incident surface 62A.
The respective polarization filters 31a, 141, 142, 143 and 144 are disposed with respect to the incident surface 62A of the light guide 34D so that light emitted from the area R47 of the polarization filter 144 passes through the area R45 of the polarization filter 143, passes through the area R43 of the polarization filter 142, passes through the area R41 of the polarization filter 141 and, further, passes through the polarization filter 31a and is incident on the first region 131 of the incident surface 62A.
By the respective polarization filters 141, 142, 143 and 144 being independently rotated within a range from 0 degrees to 90 degrees relative to the polarization filter 31a, the light amount of the illumination for a front observation image and the three light amounts for illumination for a lateral observation image can be balanced.
The control portion 42 independently drives the respective polarization filters 141, 142, 143 and 144 so that the brightnesses of the respective regions in the endoscopic image become equal.
As described above, according to the endoscope apparatus of the present embodiment, light amounts for illumination in four directions can be independently adjusted, and observation images for four directions can be made the appropriate brightness.
As described in the foregoing, according to the respective embodiments and respective modifications described above, an endoscope system can be provided in which respective observation images obtained by an endoscope that is capable of observation in two or more directions can be made the appropriate brightness.
The present invention is not limited to the above embodiments and various changes and modifications can be made within a range that does not depart from the spirit and scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-073513 | Mar 2014 | JP | national |
This application is a continuation application of PCT/JP2015/059112 filed on Mar. 25, 2015 and claims benefit of Japanese Application No. 2014-073513 filed in Japan on Mar. 31, 2014, the entire contents of which are incorporated herein by this reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2015/059112 | Mar 2015 | US |
| Child | 15262203 | US |
