Endoscopic device, endoscopic system, convergence angle modification method, and program

Abstract

To provide a technique which can change a ratio of a measurable region by changing an angle of convergence according to an object distance.SOLUTION: An endoscope device includes: an imaging optical system having two incident optical paths made of two optical systems of which optical axes are in an eccentric state to a center of imaging of an optical element; an optical action member for changing an angle of convergence; and a control unit for controlling a state of the optical action member of the imaging optical system. The control unit has a measurement operation unit for measuring a distance to an object, and changes an angle of convergence by controlling the state of the optical action member of the imaging optical system on the basis of the result of a measurement by the measurement operation unit.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The disclosure of this specification relates to an endoscope device, an endoscope system, a method for changing the convergence angle, and a program.

Background Art

[0002] As one of the functions of an endoscope device, a stereo measurement function is known. The stereo measurement function captures an object to be measured from two directions with a parallax, obtains the displacement amount of corresponding measurement points on each image by performing a correlation operation between the captured images, and measures the size, depth, etc. of an object based on the obtained displacement amount using the principle of triangulation. In such a stereo measurement function, since the overlapping region of the fields of view of two images with a parallax becomes the measurable region, it is necessary for the object to be measured to be included in each of their fields of view.

[0003] As an optical system for capturing two images with a parallax, for example, the compound eye imaging system described in Patent Document 1 is known. This compound eye imaging system has, as a means for changing the convergence angle, for example, a prism system on the subject side, and changes the convergence angle by rotating the prism constituting the prism system.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a conventional endoscope device having a stereo measurement function, since the convergence angle is fixed, the ratio of the measurable region where the fields of view of two images with a parallax overlap changes according to the subject distance (the distance to the subject).

[0006] Figure 16 shows an example in a conventional endoscope where the proportion of the measurable area changes depending on the subject distance. In this example, the area where the two fields of view 302 and 303 of the imaging optical system 301, which has a fixed convergence angle θ, overlap becomes the measurable area 304, and the area where they do not overlap becomes the unmeasurable area 305. In this case, the proportion of the measurable area of ​​the two images of fields of view 302 and 303 (two images with parallax) captured via the imaging optical system 301 changes depending on the subject distance. As an example, Figure 16 shows the measurable area 304 and unmeasurable area 305 in images 306 and 307 of the two fields of view 302 and 303, each captured with subject distances of 5 mm, 10 mm, and 25 mm, respectively. According to these images 306 and 307, the proportion of the measurable area 304 is smaller in images 306 and 307 taken at a subject distance of 5mm compared to images 306 and 307 taken at a subject distance of 10mm, while the proportion of the measurable area 304 is larger in images 306 and 307 taken at a subject distance of 25mm.

[0007] Thus, in conventional endoscopes, the convergence angle is fixed, causing the proportion of the measurable area to change depending on the subject distance. As a result, the proportion of the measurable area becomes smaller depending on the subject distance (for example, when the subject distance is 5 mm in Figure 16), reducing the usability of the stereo measurement function.

[0008] Although Patent Document 1 discloses a compound eye imaging system equipped with means for changing the convergence angle, it does not disclose any technique for changing the convergence angle according to the distance to the subject.

[0009] One aspect of the present invention is to provide a technology that can change the proportion of the measurable area by changing the convergence angle according to the distance to the subject. [Means for solving the problem]

[0010] An endoscope according to one aspect of the present invention comprises an imaging optical system having two incident light paths formed by two optical systems whose optical axes are eccentric with respect to the imaging center of an image sensor; an optical working member that changes the convergence angle; and a control unit that controls the state of the optical working member in the imaging optical system, wherein the control unit includes a measurement calculation unit that measures the distance to a subject, and changes the convergence angle by controlling the state of the optical working member in the imaging optical system based on the measurement result of the measurement calculation unit.

[0011] An endoscope system according to one aspect of the present invention is an endoscope system comprising an endoscope device and a control device, wherein the endoscope device has an imaging optical system having two incident light paths formed by two optical systems whose optical axes are eccentric with respect to the imaging center of an image sensor, and an optical working member that changes the convergence angle, and the control device has a measurement calculation unit that measures the distance to a subject, and changes the convergence angle by controlling the state of the optical working member in the imaging optical system based on the measurement result of the measurement calculation unit.

[0012] A convergence angle changing method according to one aspect of the present invention involves measuring the distance to the subject and using an optical working member in an imaging optical system having two incident light paths formed by two optical systems whose optical axes are eccentric with respect to the imaging center of the image sensor. Insertion and removal of one or each of the two incident light paths The convergence angle is changed by controlling the state based on the aforementioned distance.

[0013] A program according to one aspect of the present invention measures the distance to a subject and has two incident light paths formed by two optical systems in which the optical axis is eccentric with respect to the imaging center of the image sensor, and an optical working member in an imaging optical system Insertion and removal of one or each of the two incident light paths The processor is instructed to perform a process that changes the congestion angle by controlling the state based on the aforementioned distance. [Effects of the Invention]

[0014] According to the above embodiment, a technology can be provided that can change the proportion of the measurable area by changing the convergence angle according to the distance to the subject.

Brief Description of the Drawings

[0015] [Figure 1] It is a figure which illustrates the external appearance structure of the endoscope apparatus 1 which concerns on a 1st Embodiment. [Figure 2] It is a figure which illustrates the internal structure of the endoscope apparatus 1 which concerns on a 1st Embodiment. [Figure 3] It is a figure which illustrates the structure of the imaging optical system 15. [Figure 4] It is a figure which shows an example of arrangement of the optical action member 16 inserted in the 1st incident optical path. [Figure 5] It is a figure which shows an example of arrangement of the optical action member 16 inserted in the 1st incident optical path. [Figure 6] It is a figure which illustrates the action of the prism 16a. [Figure 7] It is a figure which illustrates the convergence angle in the case where the prism 16a is not inserted in the 1st incident optical path. [Figure 8] It is a figure which illustrates the convergence angle in the case where the prism 16a is inserted in the 1st incident optical path. [Figure 9] It is a flowchart which illustrates the process in which the control part 34 controls the insertion / removal state of the prism 16a. [Figure 10] It is a figure which illustrates graphs G1 and G2 which plot the ratio of the measurable regions at each subject distance in the case where the prism 16a is inserted in the 1st incident optical path and the case where it is not inserted. [Figure 11] It is a figure which shows a specific example in the case where the prism 16a is configured to be insertable / removable with respect to each of the 1st incident optical path and the 2nd incident optical path in the imaging optical system 15. [Figure 12] It is a figure which illustrates the action of the parallel flat plate 16b (prisms 16b1 and 16b2). [Figure 13] It is a figure which illustrates the action of the liquid crystal prism 16c arranged in the 1st incident optical path. [Figure 14] It is a figure which illustrates the imaging optical system 15 in a state where each of the apertures 143R and 143L of the diaphragm 143 is eccentric to the outside. [Figure 15]It is a diagram illustrating the hardware configuration of the computer 200. [Figure 16] It is a diagram showing an example in which the ratio of the measurable region changes according to the subject distance in a conventional endoscope device.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] <First Embodiment> FIG. 1 is a diagram illustrating the external configuration of the endoscope device 1 according to the first embodiment. The endoscope device 1 illustrated in FIG. 1 is an endoscope device having a stereo measurement function, and includes an insertion unit 10, an operation unit 20, and a main body unit 30.

[0018] The insertion unit 10 has an elongated shape that can be inserted into the subject, and includes a distal end portion 11, a bending portion 12 formed to be bendable, and a long flexible tube portion 13 having flexibility. As shown by the arrow, an optical adapter 14 can be detachably attached to the distal end portion 11. When the optical adapter 14 is attached to the distal end portion 11, the endoscope device 1 can perform measurement by the stereo measurement function.

[0019] The operation unit 20 receives user operations and has a joystick 21 and a plurality of buttons (not shown). The joystick 21 is a bending operator that receives an operation for bending the bending portion 12 in a desired direction.

[0020] The main body unit 30 includes a display unit 31, an external interface 32, and the like. The display unit 31 is a display device such as an LCD (Liquid Crystal Display) and displays images, operation screens, and the like. The display unit 31 also has a touch panel 31a that receives a touch operation by the user. The external interface 32 is connected to an external device such as an external storage device (for example, a USB (Universal Serial Bus) memory).

[0021] Figure 2 is a diagram illustrating the internal configuration of an endoscope device 1 according to the first embodiment. In the endoscope device 1 illustrated in Figure 2, the optical adapter 14 and the tip 11, when the optical adapter 14 is attached to the tip 11, include an imaging optical system 15, an optical working member 16, an image sensor 11a, a light-emitting element 11b, and an illumination optical system 17.

[0022] The imaging optical system 15 has two incident light paths formed by two optical systems whose optical axes are eccentric with respect to the imaging center of the image sensor 11a, as will be described in detail later. When the long side of the imaging area of ​​the image sensor 11a is defined as the left-right direction, such an imaging optical system 15 simultaneously forms parallax-laden subject images in the left half and the right half of the imaging area. The optical working member 16 changes the convergence angle, as will be described in detail later.

[0023] The image sensor 11a captures (photoelectrically converts) the subject image formed by the imaging optical system 15, generates an imaging signal, and outputs it to the main unit 30 (image generation unit 33). The image sensor 11a is a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, etc.

[0024] The light-emitting element 11b emits illumination light to illuminate the subject. The light-emitting element 11b is an LED (Light Emitting Diode), etc. The illumination optical system 17 irradiates the subject with the illumination light emitted by the light-emitting element 11b. In this example, the subject is illuminated with the illumination light emitted by the light-emitting element 11b, but for example, the illumination light emitted by the light source unit of the main body 30 may be guided through a light guide inserted into the insertion part 10, etc., to illuminate the subject.

[0025] The control unit 20 receives user input to the joystick 21, multiple buttons (not shown), etc., and outputs a signal corresponding to that input to the main unit 30 (control unit 34).

[0026] The main unit 30 includes the display unit 31 and external interface 32 described above, as well as an image generation unit 33, a control unit 34, and a recording unit 35. The touch panel 31a of the display unit 31 receives touch operations from the user and outputs a signal corresponding to the touch operation to the control unit 34.

[0027] The image generation unit 33 generates an image by applying predetermined signal processing to the imaging signal output from the image sensor 11a, and sequentially outputs the generated image to the control unit 34. The image generation unit 33 is composed of, for example, an image generation circuit.

[0028] The control unit 34 controls various parts of the endoscope device 1. For example, the control unit 34 controls the driving of the image sensor 11a and the light-emitting element 11b, controls the display of the display unit 31, controls the bending of the bending section 12 in response to user operation on the joystick 21, and controls the state of the optical working member 16 in the imaging optical system 15.

[0029] Furthermore, the control unit 34 performs various processes. For example, the control unit 34 displays the images sequentially output from the image generation unit 33 on the display unit 31, or records them as still images or videos on the recording unit 35 or an external storage device connected to the external interface 32. Also, for example, the control unit 34 performs measurement processing using the stereo measurement function based on the images output from the image generation unit 33.

[0030] Furthermore, the control unit 34 includes a measurement calculation unit 34a. The measurement calculation unit 34a measures the subject distance (the distance from the tip of the optical adapter 14 attached to the tip 11 to the subject) based on the image output from the image generation unit 33. The measurement of the subject distance at this time can be performed using a known method based on the principle of triangulation (for example, the method described in Japanese Patent Application Publication No. 2006-136706). Then, the control unit 34 changes the convergence angle by controlling the state of the optical working member 16 in the imaging optical system 15 based on the measurement result of the measurement calculation unit 34a.

[0031] Such a control unit 34 is composed of, for example, a processor such as a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory). The functions of the control unit 34 are realized when the processor executes a program stored in the ROM while using the RAM as a work area. The control unit 34, or the control unit 34 and the image generation unit 33, may be composed of hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0032] The recording unit 35 records still images, videos, measurement results, etc. The recording unit 35 may also record programs executed by the processor of the control unit 34. The recording unit 35 is a non-volatile memory such as an HDD (Hard Disk Drive) or SSD (Solid State Drive).

[0033] Figure 3 is a diagram illustrating the configuration of the imaging optical system 15. As illustrated in Figure 3, the imaging optical system 15 includes an adapter optical system 140 included in the optical adapter 14 and a master optical system 110 included in the tip section 11. The adapter optical system 140 includes a binocular lens 141 consisting of a left eye lens 141L and a right eye lens 141R, each having negative lens power, a coaxial lens 142 having positive lens power, an aperture (brightness aperture) 143, and a cover glass 144. The left eye lens 141L and the right eye lens 141R are two optical systems whose optical axes are eccentric with respect to the imaging center of the image sensor 11a, and the imaging optical system 15 has two incident light paths (incident light paths from the subject to the image sensor 11a) formed by these. The aperture 143 has two apertures 143L and 143R arranged to correspond to the two incident light paths. The master optical system 110 includes a cover glass 111 and a coaxial lens 112 having positive lens power.

[0034] In this imaging optical system 15, light passing sequentially from the subject through the right eye lens 141R, coaxial lens 142, aperture 143R of the diaphragm 143, cover glass 144, cover glass 111, and coaxial lens 112 is imaged onto the left half of the imaging area 11aL of the image sensor 11a. Similarly, light passing sequentially from the subject through the left eye lens 141L, coaxial lens 142, aperture 143L of the diaphragm 143, cover glass 144, cover glass 111, and coaxial lens 112 is imaged onto the right half of the imaging area 11aR of the image sensor 11a. In other words, light from two incident light paths (two subject images with parallax) is simultaneously imaged onto the left and right halves 11aL and 11aR of the imaging area of ​​the image sensor 11a. In the following, of the two incident light paths, the one passing through the right eye lens 141R, etc., will be referred to as the first incident light path, and the one passing through the left eye lens 141L, etc., will be referred to as the second incident light path.

[0035] Next, the optical working member 16 will be described. In the first embodiment, the optical working member 16 is configured to be insertable and detachable from the first incident light path in the imaging optical system 15. This insertion and detachment is performed by an actuator (not shown) included in the optical adapter 14 under the control of the control unit 34.

[0036] Figures 4 and 5 show examples of the arrangement of the optical working member 16 inserted into the first incident light path. The arrangement example in Figure 4 shows the optical working member 16 inserted between the binocular lens 141 (right eye lens 141R) and the coaxial lens 142. The arrangement example in Figure 5 shows the optical working member 16 inserted between the aperture 143 (aperture 143R) and the cover glass 144.

[0037] In the first embodiment, the optical working member 16 is a wedge-shaped prism 16a. The prism 16a has the effect of bending light rays in the direction of its thickness. Figure 6 illustrates the effect of the prism 16a. The left side of Figure 6 illustrates the effect when the prism 16a is inserted into the first incident light path with the thicker end facing outwards (away from the central axis of the coaxial lens 142), and the right side of Figure 6 illustrates the effect when the prism 16a is inserted into the first incident light path with the thicker end facing inwards (closer to the central axis of the coaxial lens 142). In Figure 6, the light rays in the first incident light path when the prism 16a is not inserted are schematically shown as dashed lines, and the light rays in the first incident light path when the prism 16a is inserted are shown as solid lines.

[0038] As illustrated on the left side of Figure 6, when prism 16a is inserted into the first incident light path with the thicker end facing outwards, the light rays are bent outwards (towards the thicker end) as indicated by the arrows, compared to when prism 16a is not inserted. On the other hand, as illustrated on the right side of Figure 6, when prism 16a is inserted into the first incident light path with the thicker end facing inwards, the light rays are bent inwards (towards the thicker end) as indicated by the arrows, compared to when prism 16a is not inserted.

[0039] Thus, since the prism 16a has the effect of bending light rays in the direction of its thickness, the convergence angle can be changed by inserting the prism 16a into the first incident light path in the orientation exemplified on the left or right side of Figure 6, as exemplified in Figure 4 or Figure 5. More specifically, the convergence angle is the angle between the principal rays of the first incident light path and the principal rays of the second incident light path. The principal rays of the first incident light path are rays that pass through the center of the opening 143R of the aperture 143 and the center of the left half of the imaging area 11aL of the image sensor 11a. The principal rays of the second incident light path are rays that pass through the center of the opening 143L of the aperture 143 and the center of the right half of the imaging area 11aR of the image sensor 11a.

[0040] Here, examples of changes in the convergence angle due to the insertion and removal of prism 16a will be explained using Figures 7 and 8. Figure 7 is an example of the convergence angle when prism 16a is not inserted into the first incident light path. Figure 8 is an example of the convergence angle when prism 16a is inserted into the first incident light path.

[0041] As illustrated in Figure 7, when the prism 16a is not inserted into the first incident light path, the convergence angle, which is the angle between the principal ray 41 of the first incident light path and the principal ray 51 of the second incident light path, is θ0. In contrast, as illustrated in Figure 8, when the prism 16a is inserted into the first incident light path in the orientation shown on the right side of Figure 6 (with the thicker side facing inward), as illustrated in Figure 4, the orientation of the field of view 42 of the first incident light path changes inward as indicated by the arrow, and the convergence angle changes to θ1 (>θ0). Also, the measurable region 61 (or the unmeasurable region 62, which is the region where the field of view 42 of the first incident light path and the field of view 52 of the second incident light path overlap) changes. That is, the proportion of the measurable region 61 (or unmeasurable region 62) according to the distance to the subject also changes.

[0042] In the endoscope device 1, the control unit 34 controls the insertion and removal state of the prism 16a according to the subject distance, thereby changing the convergence angle to one that is suitable for the subject distance (the convergence angle that increases the proportion of the measurable area). This control by the control unit 34 will be explained using Figures 9 and 10.

[0043] Figure 9 is a flowchart illustrating the process by which the control unit 34 controls the insertion and removal state of the prism 16a. This process is performed automatically by the control unit 34, for example, after the user has selected the stereo measurement mode but before the measurement target location has been specified. The stereo measurement mode is a mode that enables the user to use the stereo measurement function. Figure 10 illustrates graphs G1 and G2, which plot the percentage of the measurable area (field of view overlap) at each subject distance (each working distance (WD)) when the prism 16a is inserted into the first incident light path (as in Figure 8) and when it is not inserted (as in Figure 7). G1 is the graph when the prism 16a is inserted into the first incident light path, and G2 is the graph when the prism 16a is not inserted into the first incident light path. The convergence angle when prism 16a is inserted into the first incident light path is, for example, 3.8°, and the convergence angle when prism 16a is not inserted into the first incident light path is, for example, 1.42°.

[0044] In the process illustrated in Figure 9, first, the control unit 34 (measurement calculation unit 34a) measures the subject distance based on the image output from the image generation unit 33 (S11). Next, the control unit 34 determines whether the subject distance measured in S11 is greater than or equal to a threshold (S12). The threshold is the subject distance at which the ratio of the measurable area at each subject distance matches or approximately matches when comparing the ratio of the measurable area at each subject distance with and without the prism 16a inserted in the first incident light path. According to graphs G1 and G2 illustrated in Figure 10, the threshold is 12.5 mm.

[0045] If the result of the determination in S12 is YES, the control unit 34 controls the insertion / removal state of the prism 16a so that the convergence angle becomes smaller (S13). That is, as illustrated in Figure 7, it controls the state so that the prism 16a is not inserted into the first incident optical path. This makes it possible to increase the proportion of the measurable area compared to when the prism 16a is inserted into the first incident optical path (see graph G2 above the threshold in Figure 10).

[0046] On the other hand, if the result of the determination in S12 is NO, the control unit 34 controls the insertion / removal state of the prism 16a so that the convergence angle increases (S14). That is, as illustrated in Figure 8, it controls the prism 16a to be inserted into the first incident light path. This makes it possible to increase the proportion of the measurable area compared to when the prism 16a is not inserted into the first incident light path (see graph G1 below the threshold in Figure 10).

[0047] When S13 or S14 is completed, the process illustrated in Figure 9 is terminated.

[0048] As described above, according to the first embodiment, the proportion of the measurable area can be changed by changing the convergence angle according to the distance to the subject. Therefore, it is possible to prevent the proportion of the measurable area from decreasing with the distance to the subject, and the usability of the stereo measurement function can be improved.

[0049] In the first embodiment, the prism 16a is configured to be insertable and removable from the first incident light path in the imaging optical system 15. However, it may also be configured to be insertable and removable from the second incident light path in the imaging optical system 15, or it may be configured to be insertable and removable from each of the first and second incident light paths in the imaging optical system 15. In this case, the prism 16a inserted into the second incident light path may be inserted between the binocular lens 141 (left eye lens 141L) and the coaxial lens 142, or between the aperture 143 (aperture 143L) and the cover glass 144. Furthermore, the orientation of the prism 16a inserted into the second incident light path may be such that the thicker end faces inward or outward.

[0050] If the prism 16a is configured to be removable from the first incident optical path and the second incident optical path in the imaging optical system 15, the prism 16a inserted into the first incident optical path and the prism 16a inserted into the second incident optical path may be inserted in directions that have opposing optical effects. That is, the orientation of each prism 16a may be such that the thicker side is on the inside, or the thicker side is on the outside (in either case, the optical effects are in opposite directions). In the former case, the convergence angle can be changed to a larger value, and in the latter case, the convergence angle can be changed to a smaller value.

[0051] Figure 11 shows a specific example in which the prism 16a is configured to be removable from the first incident light path and the second incident light path in the imaging optical system 15. The upper part of Figure 11 shows the case where the prism 16a is not inserted into the first incident light path and the second incident light path, and to its right are images 43 and 53 of the field of view 42 and 52 in which a subject at subject distance D is imaged in this case. The lower part of Figure 11 shows the case where the prism 16a is inserted into the first incident light path and the second incident light path, and to its right are images 43 and 53 of the field of view 42 and 52 in which a subject at subject distance D is imaged in this case. In this specific example, the prism 16a inserted into the first incident light path and the prism 16a inserted into the second incident light path are inserted between the binocular lens 141 and the coaxial lens 142, with the thicker end facing inward.

[0052] In the specific example shown in Figure 11, inserting prisms 16a into both the first and second incident light paths causes both the field of view 42 of the first incident light path and the field of view 52 of the second incident light path to change inward, as indicated by the arrows, compared to the case where prisms 16a are not inserted, and the convergence angle changes from θ0 to θ2 (>θ0). Note that θ2 is larger than the convergence angle when prisms 16a are inserted only into the first incident light path (see θ1 in Figure 8). In addition, the proportion of the measurable area 61 (or unmeasurable area 62) changes according to the subject distance. For example, in images 43 and 53 of the field of view 42 and 52 where a subject at subject distance D is imaged, the proportion of the measurable area 61 is larger when prisms 16a are inserted than when prisms 16a are not inserted. In this specific example, that proportion is 1 (100%).

[0053] Thus, as shown in the specific example in Figure 11, by configuring the prism 16a to be removable from both the first and second incident light paths, the convergence angle can be changed more significantly depending on the distance to the subject.

[0054] <Second Embodiment> The second embodiment is an endoscope device 1 according to the first embodiment, in which the optical working member 16 is a parallel plate 16b.

[0055] The parallel plate 16b is positioned in the first incident light path of the imaging optical system 15. For example, the parallel plate 16b may be positioned between the binocular lens 141 (right eye lens 141R) and the coaxial lens 142, as illustrated in the optical working member 16 in Figure 4, or between the aperture 143 (aperture 143R) and the cover glass 144, as illustrated in the optical working member 16 in Figure 5.

[0056] The parallel plate 16b is composed of two wedge-shaped prisms 16b1 and 16b2. The prisms 16b1 and 16b2 are, for example, the prism 16a described in the first embodiment. One of the two prisms 16b1, 16b2, prism 16b1, is configured to be insertable into and removeable from the second incident light path. This insertion and removal is performed by an actuator (not shown) included in the optical adapter 14 under the control of the control unit 34. The prism 16b1 inserted into the second incident light path is inserted at a position symmetrical to the central axis of the coaxial lens 142. For example, if the parallel plate 16b is positioned between the binocular lens 141 (right eye lens 141R) and the coaxial lens 142, the prism 16b1 inserted into the second incident light path is inserted between the binocular lens 141 (left eye lens 141L) and the coaxial lens 142.

[0057] Figure 12 illustrates the function of the parallel plate 16b (prisms 16b1, 16b2). The left side of Figure 12 illustrates the function when the parallel plate 16b (prisms 16b1, 16b2) is positioned in the first incident light path, while the right side of Figure 12 illustrates the function of prisms 16b1 and 16b2 when one of the prisms 16b1 in the parallel plate 16b is inserted into the second incident light path. In Figure 12, the rays of light in the first and second incident light paths are schematically shown as solid lines when the parallel plate 16b (prisms 16b1, 16b2) is positioned in the first incident light path. Furthermore, on the right side of Figure 12, the rays of light in the first and second incident optical paths are schematically shown as dotted lines when the parallel plate 16b (prisms 16b1, 16b2) is arranged in the first incident optical path (as in the left side of Figure 12), and the rays of light in the first and second incident optical paths are shown as solid lines when one of the prisms 16b1 in the parallel plate 16b is inserted into the second incident optical path.

[0058] As illustrated on the left side of Figure 12, when the parallel plate 16b (prisms 16b1, 16b2) is placed in the first incident optical path, it has no effect on the light rays of the first and second incident optical paths. On the other hand, as illustrated on the right side of Figure 12, when one of the prisms 16b1 in the parallel plate 16b is inserted into the second incident optical path, the light rays of the second incident optical path are bent inward towards the thicker side of prism 16b1 as indicated by the arrow due to the action of prism 16b1, and the light rays of the first incident optical path are bent inward towards the thicker side of prism 16b2 as indicated by the arrow due to the action of the other prism 16b2. Note that the actions of prisms 16b1 and 16b2 illustrated on the right side of Figure 12 are the same as the actions of prism 16a explained in Figure 11.

[0059] In the second embodiment, the control unit 34 controls the insertion / removal state of one prism 16b1 in the parallel plate 16b according to the subject distance, thereby changing the convergence angle to one that is suitable for the subject distance (the convergence angle that increases the proportion of the measurable area). This control by the control unit 34 is the same as in the first embodiment: the subject distance is measured, and if it is above a threshold, the insertion / removal state of the prism 16b1 is controlled to decrease the convergence angle; if it is below the threshold, the insertion / removal state of the prism 16b1 is controlled to increase the convergence angle. That is, if the subject distance is above a threshold, the prism 16b1 is controlled to be in the state shown on the left side of Figure 12; and if the subject distance is below the threshold, the prism 16b1 is controlled to be in the state shown on the right side of Figure 12. The threshold is the subject distance at which the proportion of the measurable area at each subject distance matches or approximately matches when comparing the proportion of the measurable area when the prism 16b1 is in the state shown on the left side of Figure 12 and when it is in the state shown on the right side of Figure 12.

[0060] As described above, the same effects as the first embodiment can be obtained with the second embodiment. Furthermore, in the second embodiment, by simply inserting or removing one of the two prisms 16b1 and 16b2 that constitute the parallel plate 16b, both the field of view 42 of the first incident optical path and the field of view 52 of the second incident optical path can be changed inward, thereby changing to a larger convergence angle.

[0061] In the second embodiment, of the two prisms 16b1 and 16b2 constituting the parallel plate 16b, prism 16b1 is inserted into and removed from the second incident light path, but prism 16b2 may also be inserted into and removed from the second incident light path. In this case, by inserting prism 16b2 into the second incident light path, both prism 16b1 in the first incident light path and prism 16b2 in the second incident light path have their thicker ends facing outwards. Therefore, compared to the state in which the parallel plate 16b (prisms 16b1 and 16b2) are exemplified on the left side of Figure 12, both the field of view 42 of the first incident light path and the field of view 52 of the second incident light path can be changed outwards, and the convergence angle can be changed to a smaller value.

[0062] Furthermore, in the second embodiment, the parallel plate 16b is positioned in the first incident light path of the imaging optical system 15, but it may also be positioned in the second incident light path of the imaging optical system 15. For example, the parallel plate 16b may be positioned between the binocular lens 141 (left eye lens 141L) and the coaxial lens 142, or between the aperture 143 (aperture 143L) and the cover glass 144. In this case, one of the two prisms 16b1 and 16b2 constituting the parallel plate 16b is configured to be removable and insertable in the first incident light path at a position symmetrical with respect to the central axis of the coaxial lens 142.

[0063] <Third Embodiment> The third embodiment is an endoscope device 1 according to the first embodiment, in which the optical working member 16 is a liquid crystal prism 16c.

[0064] The liquid crystal prism 16c is positioned in the first incident light path of the imaging optical system 15. For example, the liquid crystal prism 16c may be positioned between the binocular lens 141 (right eye lens 141R) and the coaxial lens 142, as illustrated in the optical working member 16 in Figure 4, or between the aperture 143 (aperture 143R) and the cover glass 144, as illustrated in the optical working member 16 in Figure 5.

[0065] The liquid crystal prism 16c is a wedge-shaped liquid crystal lens, and when a voltage is applied, the orientation of the liquid crystal molecules changes, thereby changing the refraction angle of the light ray. The voltage to the liquid crystal prism 16c is applied by a driver circuit (not shown) included in the optical adapter 14 under the control of the control unit 34. Hereinafter, the orientation of the liquid crystal molecules when no voltage is applied to the liquid crystal prism 16c will be referred to as the first orientation state, and the orientation of the liquid crystal molecules when a voltage is applied to the liquid crystal prism 16c will be referred to as the second orientation state.

[0066] Figure 13 illustrates the function of the liquid crystal prism 16c positioned in the first incident optical path. The left side of Figure 13 illustrates the function of the liquid crystal prism 16c in the first orientation state, and the right side of Figure 13 illustrates the function of the liquid crystal prism 16c in the second orientation state. In the left side of Figure 13, the rays in the first incident optical path when the liquid crystal prism 16c is in the first orientation state are schematically shown as solid lines. In the right side of Figure 13, the rays in the first incident optical path when the liquid crystal prism 16c is in the first orientation state (left side of Figure 13) are schematically shown as dotted lines, and the rays in the first incident optical path when the liquid crystal prism 16c is in the second orientation state are shown as solid lines.

[0067] As illustrated in Figure 13, when the orientation of the liquid crystal prism 16c positioned in the first incident light path is the second orientation (right side of Figure 13), the light rays in the first incident light path are bent inward, as indicated by the arrows, compared to when it is in the first orientation (left side of Figure 13). This effect is similar to that of the prism 16a illustrated on the right side of Figure 6.

[0068] In the third embodiment, the control unit 34 controls the orientation state of the liquid crystal prism 16c according to the subject distance, thereby changing it to a convergence angle suitable for the subject distance (the convergence angle that increases the proportion of the measurable area). This control by the control unit 34 is the same as in the first embodiment: the subject distance is measured, and if it is above a threshold, the orientation state of the liquid crystal prism 16c is controlled to decrease the convergence angle; if it is below the threshold, the orientation state of the liquid crystal prism 16c is controlled to increase the convergence angle. That is, if the subject distance is above a threshold, the orientation state is controlled to be the first orientation state shown on the left side of Figure 13; and if the subject distance is below the threshold, the orientation state is controlled to be the second orientation state shown on the right side of Figure 13. The threshold is the subject distance at which the proportion of the measurable area at each subject distance matches or approximately matches when comparing the proportion of the measurable area when the liquid crystal prism 16c is in the first orientation state shown on the left side of Figure 13 and the proportion of the measurable area when it is in the second orientation state shown on the right side of Figure 13.

[0069] As described above, the same effects as the first embodiment can be obtained with the third embodiment. Furthermore, in the third embodiment, since there is no need to provide a mechanical drive mechanism to change the convergence angle, the optical adapter 14 can be made smaller.

[0070] In the third embodiment, when the orientation state of the liquid crystal prism 16c arranged in the first incident optical path is the second orientation state, the light rays of the first incident optical path are bent inward compared to when it is the first orientation state, but they may also be bent outward.

[0071] Furthermore, in the third embodiment, the liquid crystal prism 16c is placed in the first incident light path of the imaging optical system 15, but it may also be placed in the second incident light path of the imaging optical system 15, or it may be placed in both the first and second incident light paths of the imaging optical system 15. In this case, the liquid crystal prism 16c placed in the second incident light path may be placed between the binocular lens 141 (left eye lens 141L) and the coaxial lens 142, or between the aperture 143 (aperture 143L) and the cover glass 144. Also, when the orientation state of the liquid crystal prism 16c placed in the second incident light path is the second orientation state, the light rays of the second incident light path may be bent inward or outward compared to when it is the first orientation state.

[0072] When the liquid crystal prisms 16c are placed in the first and second incident optical paths of the imaging optical system 15, the liquid crystal prism 16c in the second orientation state placed in the first incident optical path and the liquid crystal prism 16c in the second orientation state placed in the second incident optical path may have opposing optical effects. That is, when each liquid crystal prism 16c is in the second orientation state, the light rays from the first incident optical path and the light rays from the second incident optical path may be bent inward or outward, compared to when each liquid crystal prism 16c is in the first orientation state (in either case, the optical effects are in opposite directions). In the former case, the convergence angle can be changed to a larger angle, and in the latter case, the convergence angle can be changed to a smaller angle.

[0073] <Fourth Embodiment> The fourth embodiment is an endoscope device 1 according to the first embodiment in which the aperture 143 also serves as the optical working member 16.

[0074] In the fourth embodiment, each of the apertures 143R and 143L of the aperture 143 is configured to be eccentrically offset outward. The eccentricity of the apertures 143R and 143L is performed by an actuator (not shown) included in the optical adapter 14, under the control of the control unit 34.

[0075] Figure 14 illustrates an imaging optical system 15 in which the apertures 143R and 143L of the aperture 143 are each eccentrically offset outwards. As illustrated in Figure 14, when the apertures 143R and 143L of the aperture 143 are each eccentrically offset outwards, both the field of view of the first incident light path and the field of view of the second incident light path become inward compared to when they are not eccentric (as in Figure 3). This effect is similar to that of the prism 16a described in Figure 11.

[0076] In the fourth embodiment, the control unit 34 controls the eccentric state of the aperture 143 according to the subject distance, thereby changing it to a convergence angle suitable for the subject distance (the convergence angle that increases the proportion of the measurable area). This control by the control unit 34 is the same as in the first embodiment: the subject distance is measured, and if it is above a threshold, the eccentric state of the aperture 143 is controlled to decrease the convergence angle; if it is below the threshold, the eccentric state of the aperture 143 is controlled to increase the convergence angle. That is, if the subject distance is above a threshold, the aperture 143 (apertures 143R, 143L) is controlled to be in an uneccentric state (state 3 in Figure 3), and if the subject distance is below the threshold, the aperture 143 (apertures 143R, 143L) is controlled to be in an eccentric state (state 14 in Figure 14). The threshold is the subject distance at which the proportion of the measurable area at each subject distance matches or approximately matches when comparing the proportion of the measurable area when the aperture 143 is uneccentric and when it is eccentric.

[0077] As described above, the same effects as the first embodiment can be obtained with the fourth embodiment. Furthermore, in the fourth embodiment, the aperture 143 also serves as the optical working member 16, so the number of components of the optical adapter 14 can be reduced compared to, for example, the first to third embodiments.

[0078] In the fourth embodiment, the apertures 143R and 143L of the aperture 143 are configured to be eccentrically eccentric outward, but they may also be configured to be eccentrically eccentric inward. In this case, when the apertures 143R and 143L are eccentrically eccentric inward, both the field of view of the first incident light path and the field of view of the second incident light path become outward-facing compared to when they are not eccentric, allowing for a smaller convergence angle.

[0079] Furthermore, in the fourth embodiment, only one of the two apertures 143R and 143L of the aperture 143 may be configured to be eccentric inward or outward. In this case, when one of the two apertures 143R and 143L is eccentric inward or outward, one of the fields of view of the first incident light path and the field of view of the second incident light path will be directed inward or outward compared to when it is not eccentric. Therefore, although the amount of change will be small, it will be possible to change to a larger or smaller convergence angle.

[0080] In the fourth embodiment, the aperture 143 having two apertures 143L and 143R can also be said to have an aperture having aperture 143L and an aperture having aperture 143R. In this case, the endoscope device 1 according to the fourth embodiment can also have an imaging optical system 15 that includes apertures arranged in each of the first and second incident light paths, with one or each of the apertures also serving as an optical working member 16, and the aperture serving as the optical working member 16 being eccentric, and the control unit 34 changing the convergence angle by controlling the eccentric state of the aperture serving as the optical working member 16 based on the measurement results of the measurement calculation unit 34a.

[0081] The first to fourth embodiments have been described above, but in each embodiment, the main unit 30 may be connected to a network by wire or wireless and may be equipped with a communication interface for communicating with external devices (such as servers) connected to the network. This allows, for example, data acquired by the endoscope device 1 to be shared on the cloud.

[0082] Furthermore, in each embodiment, the functions of a part of the main body 30 (for example, the control unit 34, etc.) may be implemented by an external control device, so that the endoscope device 1 is implemented as an endoscope system comprising an endoscope device and a control device. In this case, the control device may be implemented by a computer 200 as illustrated in Figure 15.

[0083] Figure 15 illustrates the hardware configuration of computer 200. The computer 200 illustrated in Figure 15 includes a processor 201, memory 202, input device 203, output device 204, storage device 205, portable storage medium drive 206, communication interface 207, and input / output interface 208, each of which is connected to bus 209 and can send and receive data from each other.

[0084] The processor 201 is a CPU, and it performs various processes by executing programs such as the OS (Operating System) and applications. Memory 202 includes RAM and ROM. RAM temporarily stores parts of the programs executed by the processor 201. RAM is also used as the work area of ​​the processor 201. ROM stores the programs executed by the processor 201 and various data necessary for program execution.

[0085] Input devices 203 include keyboards, mice, touch panels, joysticks, etc. Output devices 204 include display devices such as LCDs.

[0086] The storage device 205 is a device that stores data, such as an HDD or SSD. The portable storage medium drive 206 drives the portable storage medium 206a and accesses its contents to read and write data. The portable storage medium 206a is a memory device, flexible disk, optical disk, magneto-optical disk, etc. This portable storage medium 206a also includes CD-ROM (Compact Disc Read Only Memory), DVD (Digital Versatile Disc), Blu-ray disc, USB memory, SD card memory, etc.

[0087] The communication interface 207 is connected to a network by wire or wireless connection and is an interface for communicating with external devices connected to the network. The input / output interface 208 is connected to an external device such as an endoscope and is an interface for inputting and outputting data with the external device.

[0088] In such a computer 200, the programs executed by the processor 201 and the various data necessary for program execution may be stored not only in the memory 202, but also in the storage device 205 or the portable storage medium 206a. Furthermore, the programs executed by the processor 201 and the various data necessary for program execution may be stored from an external device via a network or communication interface 207 in one or more of the memory 202, storage device 205, and portable storage medium 206a.

[0089] Furthermore, the computer 200 is not limited to the configuration illustrated in Figure 15; it may be configured with multiple of the components illustrated in Figure 15, or with some components omitted. For example, the computer 200 may have multiple processors.

[0090] Furthermore, the computer 200 may be configured to include hardware such as a microprocessor, ASIC, FPGA, DSP (Digital Signal Processor), and PLD (Programmable Logic Device). For example, the processor 201 may be implemented using at least one of these pieces of hardware.

[0091] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various improvements and modifications are possible without departing from the spirit of the invention. [Explanation of Symbols]

[0092] 1 Endoscopy System 10 Insertion part 11 Tip 11a Image sensor 11b Light-emitting element 12 Curved section 13 Flexible tube section 14 Optical Adapters 15 Imaging Optical System 16 Optical working member 16a Prism 16b parallel plate 16b1, 16b2 prism 16c Liquid Crystal Prism 17 Illumination optical system 20 Control section 21 Joysticks 30 Main body 31 Display section 31a Touch Panel 32 External Interfaces 33 Image generation unit 34 Control Unit 34a Measurement and calculation unit 35 Records Section 41. Main rays 42 Field of view 43 images 51 Main rays 52 Field of view 53 images 61 Measurable area 62 Unmeasurable Region 110 Master Optical System 111 Cover glass 112 Coaxial lens 140 Adapter Optics 141 Binocular Lens 141L left eye lens 141R Right eye lens 142 Coaxial lens 143 Aperture (brightness aperture) 143L, 143R opening 144 Cover glass 200 Computers 201 Processor 202 memory 203 Input device 204 Output device 205 Storage device 206 Portable storage medium drive device 206a Portable storage medium 207 Communication Interface 208 Input / Output Interfaces Bus 209 301 Imaging Optical System 302, 303 field of view 304 Measurable area 305 Unmeasurable Region Images 306, 307 G1, G2 graphs

Claims

1. An imaging optical system having two incident light paths formed by two optical systems whose optical axes are eccentric with respect to the imaging center of the image sensor, An optical working member that changes the convergence angle, A control unit for controlling the state of the optical working member in the imaging optical system, Equipped with, The control unit, It is equipped with a measurement calculation unit that measures the distance to the subject, Based on the measurement results of the measurement calculation unit, the convergence angle is changed by controlling the state of the optical working member in the imaging optical system. An endoscope device characterized by the following features.

2. The optical working member is a prism that can be inserted into or removed from one or each of the two incident light paths. The control unit changes the convergence angle by controlling the insertion and removal state of the prism based on the measurement results of the measurement calculation unit. The endoscopic apparatus according to claim 1, characterized in that it is a feature of the present invention.

3. The optical working member is a prism that can be inserted into or removed from one of the two incident light paths. The endoscopic apparatus according to claim 2, characterized in that it is as described above.

4. The prisms inserted into each of the two incident light paths have opposing optical effects. The endoscopic apparatus according to claim 2, characterized in that it is as described above.

5. The optical working member is a parallel plate positioned in one of the two incident light paths. The parallel plate is composed of two prisms, and one of the two prisms is removable from the other of the two incident light paths. The control unit changes the convergence angle by controlling the insertion and removal state of one of the prisms in the parallel plate based on the measurement results of the measurement calculation unit. The endoscopic apparatus according to claim 1, characterized in that it is a feature of the present invention.

6. The optical working member is a liquid crystal prism placed in one or each of the two incident light paths. The control unit changes the convergence angle by controlling the orientation state of the liquid crystal molecules in the liquid crystal prism based on the measurement results of the measurement calculation unit. The endoscopic apparatus according to claim 1, characterized in that it is a feature of the present invention.

7. The optical working member is an aperture positioned in one or each of the two incident light paths. The aperture is eccentric, The control unit changes the convergence angle by controlling the eccentricity of the aperture based on the measurement results of the measurement calculation unit. The endoscopic apparatus according to claim 1, characterized in that it is a feature of the present invention.

8. The control unit controls the state of the optical working member so that the convergence angle decreases when the distance measured by the measurement calculation unit is greater than or equal to a threshold, and controls the state of the optical working member so that the convergence angle increases when the distance measured by the measurement calculation unit is less than the threshold. The endoscopic apparatus according to claim 1, characterized in that it is a feature of the present invention.

9. An endoscope system comprising an endoscope device and a control device, The aforementioned endoscope device is An imaging optical system having two incident light paths formed by two optical systems whose optical axes are eccentric with respect to the imaging center of the image sensor, An optical working member that changes the convergence angle, It has, The control device is It has a measurement calculation unit that measures the distance to the subject, Based on the measurement results of the measurement calculation unit, the convergence angle is changed by controlling the state of the optical working member in the imaging optical system. An endoscopic system characterized by the following features.

10. The endoscope device includes an optical adapter. The endoscopic system according to claim 9, characterized in that it is as described above.

11. Measure the distance to the subject, In an imaging optical system having two incident light paths formed by two optical systems whose optical axes are eccentric with respect to the imaging center of the image sensor, the convergence angle is changed by controlling the insertion and removal state of the optical working member from one or each of the two incident light paths based on the distance. A method for changing the convergence angle, characterized by the features described above.

12. Measure the distance to the subject, In an imaging optical system having two incident light paths formed by two optical systems whose optical axes are eccentric with respect to the imaging center of the image sensor, the convergence angle is changed by controlling the insertion and removal state of the optical working member from one or each of the two incident light paths based on the distance. A program characterized by having a processor execute a process.

13. In an imaging optical system having two incident light paths formed by two optical systems whose optical axes are eccentric with respect to the imaging center of the image sensor, the field of view overlap ratio of the image acquired by the imaging optical system is calculated, and the convergence angle is changed by controlling the state of the optical working member based on the field of view overlap ratio and the distance to the subject. A method for changing the convergence angle, characterized by the features described above.

Images