3D Glasses

Abstract

To provide three-dimensional glasses that can reduce a fatigue feeling of an operator in a three-dimensional endoscope surgery.SOLUTION: Three-dimensional glasses 10 include: a left eye optical filter 14a which transmits only a left-eye image in the left-eye image and a right-eye image displayed on a display screen of an image display device; a right eye optical filter 14b which transmits only the right-eye image in the left-eye image and the right-eye image; a left eye optical plate 16a which is arranged so as to overlap with the left eye optical filter 14a in the light transmission direction; and a right eye optical plate 16b which is arranged so as to overlap with the right eye optical filter 14b in the light transmission direction. The left eye and right eye optical plates 16a, 16b include a central region 21 where an average frequency varies to a minus side as being apart from an optical center O, and a peripheral region 22 in which a slope of the average frequency line per 1 degree of a visual angle is equal to or less than 0.01 diopter as an absolute value on an outer side relative to the central region 21.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to three-dimensional glasses suitably used in three-dimensional endoscopic surgery. [Background technology]

[0002] Devices that enable three-dimensional display of images, such as 3D movies and 3D televisions, have been put into practical use. Many of these are binocular 3D displays using 3D glasses. However, a problem with such binocular 3D displays is visual fatigue caused by convergence-accommodation discrepancies.

[0003] As a means of reducing visual fatigue caused by convergence-accommodation discrepancies with a simple configuration, it is effective to incorporate a wide-focus lens with varying refractive power (power) in a direction perpendicular to the optical axis into stereoscopic glasses, as proposed by the inventors of the present invention in Patent Document 1 below. By viewing stereoscopic images through a wide-focus lens, the range of stereoscopic images that can be comfortably viewed in 3D is expanded, thereby reducing visual fatigue for the user. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. WO2020 / 008804 [Overview of the project] [Problems that the invention aims to solve]

[0005] By the way, in the field of endoscopic surgery, the use of a stereoscopic endoscope for three-dimensionally displaying the image of the surgical site is also being considered. In the case of a stereoscopic movie or a stereoscopic TV, the user continuously views a stereoscopic image. In contrast, in stereoscopic endoscopic surgery using a stereoscopic endoscope, in addition to performing the surgery while viewing a plurality of 3D monitors arranged at different positions, it is necessary to obtain various information from the surrounding situation other than the 3D monitors during the surgery, and the surgeon, who is the user, has to greatly move his or her line of sight. Therefore, if distortion occurs in the appearance at the peripheral part of the lens incorporated in the stereoscopic glasses, it will cause the surgeon to feel discomfort and uneasiness, which has been one of the factors increasing the surgeon's sense of fatigue. The present invention solves the above-described problems and aims to provide stereoscopic glasses capable of reducing the fatigue of a surgeon in stereoscopic endoscopic surgery.

Means for Solving the Problems

[0006] The stereoscopic glasses according to the first aspect of the present invention are as follows. For the left-eye image and the right-eye image displayed on the display screen of the image display device, a left-eye optical filter that transmits only the left-eye image, For the left-eye image and the right-eye image, a right-eye optical filter that transmits only the right-eye image, A left-eye optical plate disposed so as to overlap the left-eye optical filter in the light transmission direction, A right-eye optical plate disposed so as to overlap the right-eye optical filter in the light transmission direction, and are stereoscopic glasses used for stereoscopic endoscopic surgery, The left-eye and right-eye optical plates are A central region in which the average power changes to the negative side as it moves away from the optical center, A peripheral region outside the central region where the absolute value of the inclination per degree of the viewing angle of the average power line is 0.01 diopter or less are provided.

[0007] According to the stereoscopic glasses of the first phase defined in this way, by observing the stereoscopic image through the central region of the optical plate, the range of convergence that allows for comfortable stereoscopic viewing is extended in front of the image display device, reducing visual fatigue caused by convergence-accommodative inconsistencies. Furthermore, by suppressing image distortion in the peripheral region of the optical plate, the occurrence of discomfort and unease caused by image distortion can be suppressed, thereby reducing the fatigue experienced by the surgeon during stereoscopic endoscopic surgery.

[0008] Here, the central region can be configured to include the region of a virtual circle with a viewing angle of 15 degrees. In this case, the change in degree within the range from the optical center to a viewing angle of 15 degrees can be set to an absolute value of 0.25 to 0.40 diopters.

[0009] Furthermore, the central region can be configured to include a virtual circle region with a viewing angle of 25 degrees. In this case, the change in degree within the range from the optical center to a viewing angle of 25 degrees can be set to an absolute value of 0.49 to 0.64 diopters.

[0010] Furthermore, the central region can be configured to include a virtual circle region with a viewing angle of 35 degrees. In this case, the change in degree within the range from the optical center to a viewing angle of 35 degrees can be set to an absolute value of 0.79 to 0.94 diopters.

[0011] As described above, the left and right eye optical plates with varying powers have a z-axis, where the z-axis is the axis passing through the optical center in the front-to-back direction, and the direction toward the rear of the optical plate is the positive direction of the z-axis, and at least one of the z-coordinate values ​​of the front and rear surfaces of the optical plate is a3r 3 +a4r 4 +a6r 6 +a8r 8 +a 10 r 10 (where r is the distance from the z axis, a3, a4, a6, a8, a 10 This can be achieved by adding an aspherical component represented by a constant (where is a constant).

[0012] Furthermore, in this invention, prescription power components for correcting at least one of myopia, hyperopia, or astigmatism can be added to the optical plates for the left and right eyes. [Brief explanation of the drawing]

[0013] [Figure 1] This diagram shows the configuration of a stereoscopic pair of glasses according to one embodiment of the present invention. [Figure 2] Figure 1 shows the optical plate, with (A) being a front view and (B) being a longitudinal cross-sectional view. [Figure 3] This diagram illustrates the relationship between accommodation and convergence. [Figure 4] This figure shows the change in average frequency along the direction perpendicular to the optical axis of the optical plate. [Figure 5] (A) is a photograph taken of a target at a different position without the optical plate, and (B) is a photograph taken of a target at a different position with the optical plate in place. [Figure 6] This figure shows a different change in average frequency compared to Figure 4. [Figure 7] This figure shows a different change in average frequency compared to Figures 4 and 6. [Figure 8] This diagram shows a modified example in which the left and right optical filters are constructed as a single eye shield. [Modes for carrying out the invention]

[0014] Next, a set of 3D glasses according to one embodiment of the present invention will be described based on the drawings. In Figure 1, 10 is a pair of stereoscopic glasses used in binocular stereoscopic display, and more specifically, stereoscopic glasses used in stereoscopic endoscopic surgery. The stereoscopic glasses 10 have a left-eye optical filter 14a and a right-eye optical filter 14b attached to the frame 12. An optical plate 16a for the left eye and an optical plate 16b for the right eye are attached in front of (opposite side of the eyeball) or behind (towards the eyeball) the left-eye optical filter 14a and the right-eye optical filter 14b, respectively, in positions that overlap with these optical filters 14a and 14b. In the following description, the left-eye optical filter 14a and the right-eye optical filter 14b may be simply referred to as "optical filter 14". Also, the left-eye optical plate 16a and the right-eye optical plate 16b may be simply referred to as "optical plate 16".

[0015] Optical filters 14a and 14b have the function of selectively transmitting the left-eye image and the right-eye image, respectively. In the 3D glasses 10, the left-eye image is blocked by the left-eye optical filter 14a, and only the light related to the left-eye image is transmitted through the left-eye optical filter 14a, with respect to the left-eye image and the right-eye image displayed on the display screen of a 3D monitor (image display device) (not shown in the illustration). Similarly, the light related to the left-eye image is blocked by the right-eye optical filter 14b, and only the light related to the right-eye image is transmitted through the right-eye optical filter 14b. As a result, the left-eye image is seen by the user's left eye 18a, and the right-eye image is seen by the user's right eye 18b.

[0016] In this example, optical filters 14a and 14b are composed of polarizers corresponding to the polarization method. In a two-lens stereoscopic display, in addition to the polarization method, there are also liquid crystal shutter methods and spectral filter methods for separating the left and right images, and it is also possible to configure optical filters 14a and 14b with liquid crystal shutters or spectral filters.

[0017] FIG. 2 shows the optical plate 16, where (A) is a front view of the optical plate 16 and (B) is a longitudinal sectional view of the optical plate 16. This optical plate 16 is in the shape before processing the outer shape according to the shape of the frame 12 and has a circular shape when viewed from the front. In the following description, the "upper" and "lower" of the optical plate 16 refer to the "upper" and "lower" for a user wearing three-dimensional glasses.

[0018] As shown in FIG. 2(A), the optical plate 16 includes a central region 21, a peripheral region 22 provided outside the central region 21, and an intermediate region 23 located between the central region 21 and the peripheral region 22.

[0019] The central region 21 is a region including the optical center O of the optical plate 16 and is used during stereoscopic vision. As described in the above Patent Document 1, in stereoscopic vision, if the convergence position and the adjustment position coincide, visual fatigue due to convergence adjustment contradiction does not occur. However, in order to achieve comfortable stereoscopic vision without visual fatigue, it is not necessary for the convergence position and the adjustment position to completely coincide, and it is known that there is a certain tolerance range for the coincidence of the convergence position and the adjustment position.

[0020] FIG. 3 is a diagram showing the relationship between convergence and adjustment. In the figure, the horizontal axis represents convergence and the vertical axis represents adjustment. The unit is diopter (D), which is the reciprocal of the distance expressed in meters. Even when the convergence and the adjustment do not coincide, if they are in a relationship such that they are located between D far and D near shown in FIG. 3, comfortable stereoscopic vision without visual fatigue is possible. That is, there is a tolerance range for the coincidence of convergence and adjustment to achieve comfortable stereoscopic vision. Here, the display area of a stereoscopic image that can be stereoscopically viewed comfortably can be represented by using the distal end D far and the proximal end D near corresponding to the depth Dv perceived by convergence. D far , D near are expressed using Dv as D far = 1.129D v + 0.442 ··· Equation (1) D near =1.035D v -0.626...Equation (2) It is given as follows.

[0021] For example, suppose the observation distance to the 3D monitor screen (display screen) in 3D endoscopic surgery is 1.4m (0.71D). When the eye is focused at this observation distance, D is calculated using equations (1) and (2). far =0.71D, D near = 0.71D v When calculated, the convergence range M1 for comfortable stereoscopic viewing is found to be 0.77m (1.3D) to 4.1m (0.24D). Considering that stereoscopic endoscopic surgery primarily displays the image in front of the 3D monitor, it is important to eliminate the uncomfortable region (the region where convergence-accommodation contradiction occurs) located in front of the 3D monitor in order to reduce the surgeon's visual fatigue. In this case, by extending the range in which the optical plate 16 is considered to be in focus (depth of field) toward the front of the 3D monitor, the region in which comfortable stereoscopic viewing without causing visual fatigue is possible can be expanded toward the front of the 3D monitor.

[0022] For example, if the focal length during observation is changed from 6.25m (-0.16D) to -∞ (0D) via the optical plate 16, the range in which the eye can focus becomes 0.71D to 0.87D. Equations (1) to (2) show D far =0.71D, D near = 0.87D v When this is calculated, the convergence range M2 in which stereoscopic viewing is comfortable expands to 0.69m (1.44D) to 4.1m (0.24D). In other words, a comfortable area extends in front of the 3D monitor. For this reason, in this example, the depth of field of the optical plate 16 is extended in front of the 3D monitor by changing the average degree to the negative side as the distance from the optical center O in the central region 21 increases.

[0023] Figure 4 shows the change in the average frequency along the direction perpendicular to the optical axis of the optical plate 16. The viewing angle α shown in the figure represents the angle when the center of the eyeball is positioned 25 mm from the refractive surface on the rear side of the lens on the optical axis of the optical plate 16. The value of the viewing angle α increases as you move towards the periphery of the optical plate 16 (see Figure 2(B)).

[0024] In the example shown in Figure 4, the central region 21, which includes the optical center O, is defined as being the size of a virtual circle with a viewing angle of 25 degrees. In the central region 21, the average frequency changes approximately linearly in the negative direction from the optical center O towards the periphery of the optical plate. Specifically, the frequency change L1 (see Figure 4) within the range from the optical center O to a viewing angle of 15 degrees is defined as 0.25 to 0.40 diopters in absolute value, and the frequency change L2 within the range from the optical center to a viewing angle of 25 degrees is defined as 0.49 to 0.64 diopters in absolute value.

[0025] Increasing the amount of frequency change expands the range in which comfortable stereoscopic vision is possible. However, if the amount of frequency change is excessively large, the image resolution will decrease. For this reason, in this example, the amount of frequency change is defined as described above, taking into consideration the range in which the stereoscopic image is actually displayed during stereoscopic endoscopic surgery.

[0026] On the other hand, the peripheral region 22 outside the central region 21 is defined as a region with a constant frequency, suppressing frequency changes. This is to suppress image distortion at the periphery of the optical plate. In this example, as shown in the partially enlarged view of Figure 4, the slope β of the average frequency line in the peripheral region 22 of the optical plate 16 is defined to be 0.01 diopters or less in absolute value per degree of viewing angle. Preferably it is 0.005 diopters or less, and more preferably 0.0025 diopters or less. As shown in Figure 4, the average frequency line, which gradually shifts to the negative side with a nearly constant slope in the central region 21, gradually decreases its slope in the intermediate region 23 between the central region 21 and the peripheral region 22, and the average frequency remains nearly constant in the peripheral region 22. Such a change in average frequency along the direction perpendicular to the optical axis can be obtained by adding an aspherical component to at least one of the front and rear surfaces of the optical plate 16.

[0027] Next, the shape of the optical plate 16 will be described. As shown in Figure 2, the optical plate 16 has a concave surface defined by equation (i) on its rear surface 25 and a convex surface defined by equation (ii) on its front surface 26. The z-axis is defined as the axis in the front-to-back direction passing through the optical center O of the optical plate 16 (base point O1 on the rear surface 25 and base point O2 on the front surface 26), and the direction toward the rear of the optical plate 16 is defined as the positive direction of the z-axis. The z-axis coincides with the optical axis of the optical plate 16.

[0028] z=r 2 / (R1+(R1 2 -Kr 2 ) 1 / 2 ) + δ …Equation (i) z=r 2 / (R2+(R2 2 -Kr 2 ) 1 / 2 ) …Formula (ii)

[0029] In equations (i) and (ii), r is the distance from the z-axis. That is, if we consider a Cartesian coordinate system with the base point O1 at the rear surface 25 and the base point O2 at the front surface 26 as the base points O2, and the axes perpendicular to the z-axis in the left-right and up-down directions as the x-axis and y-axis, respectively, then r = (x 2 +y 2 ) 1 / 2 Here, R1 and R2 are the radii of curvature at the vertices of the surface, and K is the conic coefficient. The rear surface 25 of the optical plate 16 is a rotationally symmetric aspherical shape represented by equation (i) above. In equation (i) defining the rear surface 25, δ is a3r 3 +a4r 4 +a6r 6 +a8r 8 +a 10 r 10 (where r is the distance from the z axis, a3, a4, a6, a8, a 10 The aspherical component is represented by a constant. Therefore, in this example, the optical plate 16 has a spherical front surface 26 and an aspherical rear surface 25. R1 and R2 are determined by the prescription power (0D in this example).

[0030] For example, the change in average frequency shown in Figure 4 is obtained by defining the constants in equations (i) and (ii) above as follows, in an optical plate 16 with a central thickness of 2.1 mm made of a material with a refractive index n: 1.608. Rear radius of curvature R1: 146.78mm, front radius of curvature R2: 147.57mm, K: -0.6, A3: 1.84×10 -05 a4: 8.10 x 10 -08 a6:-3.79×10 -10 a8:2.79×10 -13 a 10 :-7.42×10 -17

[0031] Figure 5 shows the effect when using the optical plate 16. The evaluation was performed as follows: A target 1 labeled "SCREEN" was placed in front of the lens of a camera with an entrance pupil diameter of 5 mm, which is the average pupil diameter of a human, at a distance of 1.4 m (corresponding to the distance to the display screen of a 3D monitor), and a target 2 labeled "3D IMAGE" was placed at a distance of 1.15 m (corresponding to the distance to the displayed stereoscopic image). Targets 1 and 2 were photographed with the camera focused on target 2. Figure 5(A) is a photograph of the target taken without the optical plate, and (B) is a photograph of the target taken with the optical plate 16.

[0032] Comparing (A) and (B) in Figure 5, the letters of target 1 appear blurred in (A) without the optical plate, whereas in (B) with the optical plate, the letters of target 1 appear sharper than in (A), and there is little difference compared to the letters of target 2 which are in focus, indicating a large difference in depth of field between (A) and (B). In other words, by using the optical plate 16, the range in which focus can be achieved is widened, and consequently, the range in which comfortable stereoscopic viewing can be achieved can also be expanded.

[0033] With the stereoscopic glasses 10 configured as described above, by observing the stereoscopic image through the central region 21 of the optical plate 16, the area in which stereoscopic vision can be clearly seen can be expanded, and image distortion in the peripheral region 22 of the optical plate 16 can be suppressed. As a result, fatigue in the surgeon caused by convergence accommodation discrepancies and image distortion during stereoscopic endoscopic surgery can be reduced.

[0034] In this invention, the size of the central region 21 in the optical plate 16 can be changed as appropriate. Figure 6 shows the change in average frequency when the central region 21 of the optical plate 16 is reduced in size and the region with constant frequency provided around the optical plate is expanded. In this example, the central region 21 is defined as being sized to include the area of ​​a virtual circle with a viewing angle of 15 degrees, and the degree change L1 within the range from the optical center to a viewing angle of 15 degrees is set to an absolute value of 0.25 to 0.40 diopters. Therefore, in the example in Figure 6, the slope of the average degree line in the central region 21 is approximately the same as in Figure 4, and the effect of extending the range of convergence that allows for comfortable stereoscopic viewing in front of the 3D monitor through the central region 21 can be obtained in the same way as in Figure 4. On the other hand, the peripheral region 22, where the degree change is suppressed, is provided over a wider area than in Figure 4, and the effect of suppressing distortion over a wider area of ​​the optical plate 16 can be obtained.

[0035] For example, the change in average frequency shown in Figure 6 can be achieved in an optical plate 16 with a central thickness of 2.1 mm made of a material with a refractive index n: 1.608 by defining the constants in equations (i) and (ii) as follows. K: -3.0, a3: 2.22 × 10 -05 a4: -2.86 × 10 -07 a6: 4.24 × 10 -11 a8:3.56×10 -14 a 10 :-1.72×10 -17

[0036] Figure 7 shows the change in average frequency when the central region 21 of the optical plate 16 is enlarged, the opposite of Figure 6, and the region with constant frequency around the optical plate is narrowed. In this example, the central region 21 is defined as being large enough to include the area of ​​a virtual circle with a viewing angle of 35 degrees, with the change in frequency L1 within the range of the optical center to a viewing angle of 15 degrees being 0.25 to 0.40 diopters in absolute value, the change in frequency L2 within the range of the optical center to a viewing angle of 25 degrees being 0.49 to 0.64 diopters in absolute value, and the change in frequency L3 within the range of the optical center to a viewing angle of 35 degrees being 0.79 to 0.94 diopters in absolute value. As shown in the example in Figure 7, it is possible to suppress image distortion around the optical plate while extending the convergence range that allows for comfortable stereoscopic viewing over a wider area than in the case of Figure 4 (i.e., even when the line of sight is shifted from the optical center) in front of the 3D monitor.

[0037] For example, the change in average frequency shown in Figure 7 can be achieved in an optical plate 16 with a central thickness of 2.1 mm made of a material with a refractive index n: 1.608 by defining the constants in equations (i) and (ii) as follows. K: 0.2, a3: 1.84 × 10 -05 a4: -1.88 × 10 -08 a6:-6.21×10 -12 a8: -6.85 × 10 -14 a 10 :3.53×10 -17

[0038] Although embodiments of the present invention have been described in detail above, these are merely examples, and the present invention can be implemented in various modified forms without departing from its spirit. For example, in the above embodiment, separate left and right optical filters are attached to the frame, but as shown in Figure 8, it is also possible to construct the left and right optical filters as a single integrated eye shield 40. This enhances the effect of protecting the surgeon's eyes from splashes such as blood. Furthermore, in the above embodiment, an aspherical component was added to the rear surface of the optical plate, but in some cases, an aspherical component may be added to the front surface of the optical plate, or it may be possible to add aspherical components to both the front and rear surfaces. Furthermore, in the above embodiment, the peripheral region of the optical plate was made a region with a constant frequency over its entire circumference, but in some cases, it is also possible to provide a region with a constant frequency only in a part of the circumferential direction. Furthermore, in the above embodiment, a plano lens with virtually no prescription is used as the optical plate for the 3D glasses, but it is also possible to add a power component to the optical plate to correct at least one of myopia, hyperopia, or astigmatism. Furthermore, in the above embodiment, the optical filter and the optical plate were constructed as separate components, but in some cases, it is also possible to integrate the optical filter and the optical plate by, for example, placing a polarizing film equivalent to the optical filter as an inner layer inside the optical plate. [Explanation of Symbols]

[0039] 10 3D Glasses 14, 14a, 14b Optical Filters 16,16a,16b Optical plate 21 Central area 22 Peripheral area L1, L2, L3 frequency change O optical center α viewing angle β Slope of the mean frequency line

Claims

1. A left-eye optical filter that transmits only the left-eye image to the left-eye image and the right-eye image displayed on the display screen of an image display device, A right-eye optical filter that transmits only the right-eye image to the left-eye image and the right-eye image, The optical plate for the left eye is arranged so as to overlap with the optical filter for the left eye in the direction of light transmission, A pair of 3D glasses for use in 3D endoscopic surgery, comprising the aforementioned optical filter for the right eye and an optical plate for the right eye arranged to overlap in the direction of light transmission, The optical plates for the left and right eyes are as follows: In the central region, the average frequency changes to the negative side as you move away from the optical center, A peripheral region is provided outside the aforementioned central region, in which the slope of the average degree line per degree of viewing angle is 0.01 diopters or less in absolute value. The aforementioned central region is composed of a virtual circle with a viewing angle of 15 degrees, and the amount of change in power within the range from the optical center to a viewing angle of 15 degrees is 0.25 to 0.40 diopters in absolute value, in a stereoscopic eyeglass.

2. The stereoscopic eyeglasses according to claim 1, wherein the central region comprises a virtual circle region with a viewing angle of 25 degrees, and the amount of change in power within the range from the optical center to a viewing angle of 25 degrees is 0.49 to 0.64 diopters in absolute value.

3. The stereoscopic eyeglasses according to claim 2, wherein the central region comprises a virtual circle with a viewing angle of 35 degrees, and the amount of change in power within the range from the optical center to a viewing angle of 35 degrees is 0.79 to 0.94 diopters in absolute value.

4. When the axes in the front-back direction passing through the optical centers of the left-eye and right-eye optical plates are defined as the z-axis, and the direction toward the rear of the optical plate is defined as the positive direction of the z-axis, at least one of the z coordinate values of the front and rear surfaces of the optical plate has an aspherical component represented by a 3 r 3 + a 4 r 4 + a 6 r 6 + a 8 r 8 + a 10 r 10 (where r is the distance from the z-axis, and a 3 , a 4 , a 6 , a 8 , a 10 are constants). The three-dimensional glasses according to any one of claims 1 to 3, to which the aspherical component is added.

5. The three-dimensional eyeglasses according to claim 4, wherein the optical plates for the left and right eyes are further provided with prescription power components for correcting at least one of myopia, hyperopia, or astigmatism.

Images