Magnifier device

Abstract

The present invention reduces the size and weight of a magnifier device capable of automatically adjusting a user's focus for magnified images of viewing targets located at different distances.　Provided is a magnifier device comprising: a magnifying optical unit 4 configured to output a magnified image of a viewing target to a user; a distance detection unit 21 configured to detect a distance to the viewing target; and a focus adjustment unit configured to adjust a focus of the magnified image output from the magnifying optical unit 4 on the basis of a detection result of the distance detection unit 21, the focus adjustment unit including: a varifocal lens 3 disposed on an optical path passing through the magnifying optical unit 4 and configured to have a changeable focal length; and a control unit 10 configured to control the focal length of the varifocal lens 3, on the basis of the detection result of the distance detection unit 21, to an adapted focal length adapted to the user's eye.

Description

Magnifying glass device

[0001] The present invention relates to a magnifying glass device used for a user to view a magnified image of a viewing object.

[0002] Patent Document 1 discloses an operating loupe (magnifying glass device) used for an operator to magnify and view a viewing object during surgery. This operating loupe is integrated with glasses or a glasses frame and is worn on the face of the operator (user) for use. This operating loupe includes a distance measuring sensor unit (distance detecting unit) that measures the distance to the viewing object (viewing distance), and a focus adjusting unit that automatically performs focus adjustment (diopter adjustment) based on the measured distance. In this focus adjusting unit, the position of the focusing lens is moved by controlling a focus adjusting drive unit (moving mechanism) that moves the position of the focusing lens by a control unit to perform focus adjustment.

[0003] Japanese Unexamined Patent Application Publication No. 2018 - 105974

[0004] However, in the conventional magnifying glass device, in order for each user with various refractive anomalies such as myopia and hyperopia to focus on the magnified image of the viewing object, a moving mechanism for moving the position of the focusing lens is required, so there is a problem that miniaturization and weight reduction are difficult.

[0005] One aspect of the present invention is a magnifying glass device comprising: a magnifying optical unit that outputs a magnified image of an object viewed by the user; a distance detection unit that detects the distance to the object; and a focus adjustment unit that adjusts the focus of the magnified image output from the magnifying optical unit based on the detection result of the distance detection unit, wherein the focus adjustment unit is arranged on the optical path passing through the magnifying optical unit and has a variable focus lens whose focal length can be changed, and a control unit that controls the focal length of the variable focus lens to a suitable focal length that suits the user's eye based on the detection result of the distance detection unit. In this magnifying glass device, the focus adjustment unit adjusts the focus of the magnified image output from the magnifying optical unit based on the detection result of the distance detection unit that detects the distance to the object. The focus adjustment unit in this magnifying glass device has a variable focus lens, and the focal length of the variable focus lens is controlled to a suitable focal length that suits the user's eye based on the detection result of the distance to the object by the distance detection unit. As a result, it is possible to automatically adjust the user's focus for magnified images of objects at different distances. Furthermore, variable-focus lenses allow for changes in focal length without requiring a mechanism to move the lens position, making miniaturization and weight reduction easy. Therefore, it becomes easy to realize a small and lightweight magnifying glass device using a small and lightweight variable-focus lens. Miniaturization and weight reduction of a magnifying glass device are significant advantages that directly improve user convenience, especially when the magnifying glass device is worn on the user's face or other body parts.

[0006] In the magnifying glass device described above, the focus adjustment unit may have a storage unit that stores focal length identification information for identifying the focal length of the variable focus lens according to the distance to the object to be viewed, and the control unit may control the focal length of the variable focus lens to the suitable focal length based on the detection result of the distance detection unit and the focal length identification information in the storage unit. In this magnifying glass device, focal length identification information for identifying the focal length of the variable focus lens that is suitable for the user according to the distance to the object to be viewed is stored in the storage unit in advance. The distance to the object that the user views through the magnifying glass device is detected by the distance detection unit, and the control unit controls the focal length of the variable focus lens to become the suitable focal length based on the detection result and the focal length identification information in the storage unit. As a result, by storing in advance focal length identification information for identifying a different suitable focal length for each user in the storage unit, it is possible to automatically adjust the focus for each user for the magnified image of any object to be viewed at different distances.

[0007] In the magnifying glass device described above, the magnifying optical unit may be a magnifying optical system including an objective lens and an eyepiece lens. This allows for a simpler configuration of the magnifying optical unit, resulting in a smaller and lighter magnifying optical unit. Therefore, this simplifies the configuration of the magnifying glass device and is further advantageous for miniaturizing and reducing the weight of the magnifying glass device.

[0008] In the magnifying glass device described above, the variable focus lens may be a shape-variable lens in which the shape of the refractive surface changes and the focal length changes according to an electrical signal controlled by the control unit. Since such a shape-variable lens is small and lightweight, it is even more advantageous in realizing a small and lightweight magnifying glass device.

[0009] The magnifying glass device may include a pair of left and right automatic focusing magnifying glass units equipped with the magnifying optical unit and the variable focus lens, and a holding unit for holding the pair of left and right automatic focusing magnifying glass units. This makes it possible to provide a binocular magnifying glass device.

[0010] The magnifying glass device may have a distance adjustment unit that adjusts the distance between the left and right pair of automatic focusing magnifying glass units to match the interpupillary distance of the user. This allows the distance between the left and right pair of automatic focusing magnifying glass units (the distance between the output units that output a magnified image to the user's eye) to be adjusted to match the interpupillary distance of each user. Therefore, it is not necessary to individually design and manufacture binocular magnifying glass devices, and a general-purpose binocular magnifying glass device can be provided in which the distance between the left and right pair of automatic focusing magnifying glass units can be adjusted to match the interpupillary distance of the user.

[0011] In the magnifying glass device described above, the holding portion may include an eyeglass frame. This allows the user to wear and use the magnifying glass device with the same comfort as wearing eyeglasses. The eyeglass frame consists of, for example, the temples and nose pads of eyeglasses.

[0012] The magnifying glass device may have a mounting portion for attaching it to the user's personal equipment. This allows the user to wear and use the magnifying glass device by attaching it to the user's personal equipment (such as eyeglasses, goggles, a headband, or a helmet) which is composed separately from the magnifying glass device.

[0013] According to the present invention, it is possible to miniaturize and lighten a magnifying glass device that can automatically adjust the user's focus to magnified images of objects at different distances.

[0014] Figure 1 is a perspective view showing the external appearance of a binocular loupe according to an embodiment. Figure 2 is a schematic cross-sectional view showing the autofocus magnifying glass section of the binocular loupe. Figure 3 is a cross-sectional view showing the schematic configuration of the variable focus lens in the autofocus magnifying glass section. Figure 4 is a plan view showing the schematic configuration of the variable focus lens. Figure 5 is a block diagram showing the configuration of the control device of the binocular loupe. Figure 6 is an explanatory diagram showing an example of table data, which is focal length identification information stored in the memory section of the control device. Figure 7 is a flowchart showing an example of a setting mode for focal length control in the embodiment. Figure 8 is a flowchart showing an example of a usage mode for focal length control in the embodiment. Figure 9 is a graph for explaining the approximation formula calculated from the table data. Figure 10 is a schematic front view showing another configuration of the binocular loupe according to an embodiment.

[0015] The following describes one embodiment in which the present invention is applied to a binocular magnifying glass as a magnifying glass device. In this embodiment, the magnifying glass device will be described using a spectacle-type binocular magnifying glass that is worn on the face of the user (hereinafter referred to as "user") as an example, but is not limited to this.

[0016] For example, a magnifying glass device is preferable if it is a device worn by the user, such as a goggle type that is attached to the user's face using the tension of a band wrapped around the back of the user's head, or a helmet type that is worn on the user's head, rather than a glasses type where the temples of the eyeglass frame are placed over the user's ears and attached to the user's face. Furthermore, it is not limited to a device worn by the user; it may also be a stationary magnifying glass device used in a workplace or other location, or a handheld magnifying glass device that is held in the user's hand. The type of magnifying glass device is selected appropriately according to its intended use.

[0017] Figure 1 is a perspective view showing the external appearance of a binocular loupe 1, which is a spectacle-type binocular magnifying glass according to this embodiment. The binocular loupe 1 in this embodiment mainly comprises a spectacle frame 2, a pair of left and right auto-focusing magnifying glass sections 5, 5, and a loupe body section 6.

[0018] The eyeglass frame 2 comprises a bridge portion 2a, a pair of left and right temple portions 2b, 2b, a pair of left and right end portions 2c, 2c, and a pair of left and right transparent plate portions 2d, 2d.

[0019] The bridge portion 2a is positioned so as to be out of the wearer's field of vision when the glasses are worn, and extends horizontally between the left and right temple portions 2b, 2b. Endpiece portions 2c, 2c are provided at both ends of the bridge portion 2a in the horizontal direction, and the left and right temple portions 2b, 2b are connected to both ends of the bridge portion 2a via the endpiece portions 2c, 2c.

[0020] The temple portions 2b, 2b are components that are placed on the user's ears when the user puts on the binocular magnifier 1. In this embodiment, the left and right temple portions 2b, 2b are configured to be folded toward the left-right center of the binocular magnifier 1 by the hinge portions provided on the endpiece portions 2c, 2c.

[0021] The pair of transparent plates 2d, 2d are held by the bridge 2a and are positioned in front of the user's left and right eyes when the user wears the binocular loupe 1. The transparent plates 2d, 2d are primarily for protecting the user's eyes. For example, the transparent plates 2d, 2d protect the pair of automatic focusing magnifying glass units 5, 5, which are positioned in front of the user's left and right eyes, from coming into contact with the user's eyes for any reason. The transparent plates 2d, 2d may also be prescription lenses or astigmatism-correcting lenses.

[0022] Figure 2 is a schematic cross-sectional view showing the autofocus magnifying glass section 5 of the binocular loupe 1 in this embodiment. The binocular loupe 1 in this embodiment is provided with two autofocus magnifying glass sections 5, 5, one for each of the user's eyes, forming a left and right pair. The two autofocus magnifying glass sections 5, 5 have substantially the same configuration, and each autofocus magnifying glass section 5, 5 is equipped with a variable focus lens 3 and a magnifying optical section 4.

[0023] The magnifying optical unit 4 of this embodiment is composed of a magnifying optical system including an objective lens 4a and an eyepiece lens 4b. The objective lens 4a and the eyepiece lens 4b are held and fixedly positioned on the inner wall of the lens barrel 4c. For example, a simple Galilean magnifying optical system can be used for the magnifying optical unit 4, using a convex lens for the objective lens 4a and a concave lens for the eyepiece lens 4b. In this case, because the configuration is simple, it is easier to realize a simpler and lighter magnifying optical unit 4.

[0024] Furthermore, the magnifying optical unit 4 can also be a prism-type magnifying optical system (such as a Porro prism or roof prism type) in which a prism is arranged in the optical path between the objective lens 4a and the eyepiece lens 4b. The magnifying optical unit 4 is not particularly limited as long as it is capable of outputting a magnified image of the object being viewed by the user.

[0025] As shown in Figure 2, in this embodiment, the automatic focusing magnifying glass unit 5 has a lens holder 5a attached to the eyepiece side portion of the lens barrel 4c that holds the objective lens 4a and eyepiece lens 4b of the magnifying optical unit 4, thereby holding the variable focus lens 3. As a result, the variable focus lens 3 is positioned near the downstream side of the optical path of the eyepiece lens 4b of the magnifying optical unit 4 so that their optical axes LO coincide. In this embodiment, the lenses provided in the automatic focusing magnifying glass unit 5 (the objective lens 4a and eyepiece lens 4b of the magnifying optical unit 4, and the variable focus lens 3) are all fixed in place, and there is no mechanism to move the positions of these lenses. Therefore, the automatic focusing magnifying glass unit 5 can be made small and lightweight.

[0026] However, the magnifying optical unit 4 may be configured to include a mechanism for moving the position of the lens. In other words, it is sufficient if the configuration for the user to adjust the focus (i.e., the variable focus lens 3 in this embodiment) does not include a mechanism for moving the position of the lens.

[0027] In this embodiment, as described above, the automatic focusing magnifying glass unit 5 has the magnifying optical unit 4 positioned upstream and the variable focus lens 3 positioned downstream in the optical path (the optical path from the object to the user's eye) passing through the magnifying optical unit 4. Therefore, the image of the object viewed by the user through the binocular loupe 1 is magnified by the magnifying optical unit 4, and the magnified image output from the magnifying optical unit 4 is output to the user's eye through the variable focus lens 3.

[0028] The arrangement of the variable focus lens 3 relative to the magnifying optical unit 4 is not limited to the arrangement in this embodiment. For example, the variable focus lens 3 can be positioned upstream and the magnifying optical unit 4 downstream. It is also possible to position the variable focus lens 3 inside the magnifying optical unit 4, for example, in the optical path between the objective lens 4a and the eyepiece lens 4b.

[0029] The variable focus lens 3 in this embodiment is not limited in its configuration as long as it can electrically control the focal length of the lens without requiring a movement mechanism to move the position of the lens. However, it is preferable that the variable focus lens 3 is a shape-variable lens in which the focal length changes by changing the shape of the refractive surface. Among shape-variable lenses, a liquid lens (also called an electrowetting device, etc.) is preferred, in which the focal length can be changed by electrically controlling the wettability of the liquids and changing the shape of the interface, using the interface of two types of liquids as the refractive surface. With a liquid lens, high-speed and highly flexible control of the focal length is possible.

[0030] Figure 3 is a cross-sectional view showing the schematic configuration of the variable focus lens 3 in this embodiment. Figure 4 is a plan view showing the schematic configuration of the variable focus lens 3 in this embodiment. As shown in Figure 3, the variable focus lens 3 in this embodiment has a configuration in which an insulating liquid 311 and a conductive liquid 312, which are in contact in an unmixed state at interface I, are sealed by an annular first electrode 301 and two transparent window members 303 and 304 that close the upper and lower ends of the first electrode 301. The insulating liquid 311 is, for example, an oily liquid, and the conductive liquid 312 is, for example, an aqueous liquid with relatively low conductivity. A voltage V0 is applied to the first electrode 301, but in this embodiment, since the annular first electrode 301 is grounded, V0 = 0V. Furthermore, the first electrode 301 is insulated from the sealed insulating liquid 311 and conductive liquid 312 by an insulating layer 301a.

[0031] Furthermore, in this embodiment, the variable focus lens 3 has multiple pairs of second electrodes 302A, 302B, ... arranged symmetrically with respect to the axis O of the first electrode 301. In this embodiment, as shown in Figure 4, four pairs of second electrodes 302A to 302H are arranged on a circle centered on the axis O, providing a total of eight second electrodes 302A to 302H.

[0032] As shown in Figure 3, the second electrodes 302A to 302H are positioned in contact with the conductive liquid 312. When voltages VA to VH are applied to each of the second electrodes 302A to 302H, a potential difference is generated between each of the second electrodes 302A to 302H and the first electrode 301, and the electrowetting effect can displace the end Ia of the insulating liquid 311 (the end Ia of interface I) along the insulating layer portion 301b on the first electrode 301. As the end Ia of the insulating liquid 311 is displaced in this way, the shape of the insulating liquid 311 changes, and the curvature of interface I is changed. Therefore, by controlling the voltages VA to VH applied to the second electrodes 302A to 302H, the focal length of the variable focus lens 3, which uses interface I as its refractive surface, can be changed.

[0033] In particular, the variable focus lens 3 of this embodiment can deform the interface I, which is a refractive surface, into a diffusion lens (concave lens), a planar lens, or a focusing lens (convex lens) by controlling the voltages VA to VH applied to the second electrodes 302A to 302H.

[0034] The variable focus lens 3 of this embodiment can change the focal length within a range of -15D to +15D in diopter equivalent (reciprocal of focal length). By using a variable focus lens 3 with such a wide range of focal length variation, it is possible to accommodate users with low vision, such as those with amblyopia.

[0035] In this embodiment, by applying the same voltage to all second electrodes 302A to 302H, which are positioned symmetrically with respect to the axis O of the first electrode 301, the focal length can be changed while keeping the optical axis of the variable focus lens 3 aligned with the axis O of the first electrode 301. On the other hand, by applying different voltages to each of the second electrodes 302A to 302H, it is possible not only to change the focal length but also to shift or tilt the optical axis of the variable focus lens 3. In other words, the variable focus lens 3 of this embodiment can change either the position and direction of the optical axis, or both, by controlling the applied voltages VA to VH.

[0036] As shown in Figure 1, the main body 6 of this embodiment is attached to a holding arm 2e supported at the left-right center of the bridge portion 2a of the eyeglass frame 2. The main body case 6a of the main body 6 is provided with a distance adjustment unit 6b that adjusts the distance between a pair of left and right autofocus magnifying glass units 5, 5 (the distance between the output units that output a magnified image to the user's eye). Specifically, the distance adjustment unit 6b in this embodiment adjusts the inter-lens distance between the variable focus lenses 3, 3, which are provided on the left and right pair of autofocus magnifying glass units 5, 5. The inter-lens distance can be defined, for example, by the distance between the reference positions on the variable focus lenses 3, 3 (for example, the center positions of the variable focus lenses 3, 3). Here, the reference positions of the variable focus lenses 3, 3 are equal to, for example, the optical center positions of the variable focus lenses 3, 3, and the inter-lens distance is equal to the distance between the optical centers of each variable focus lens 3, 3.

[0037] By providing such a distance adjustment unit 6b, it is not necessary to individually design and manufacture the binocular loupe 1 to match each user's interpupillary distance PD, and a general-purpose binocular loupe 1 can be provided in which the distance between the left and right pair of automatic focusing magnifying units 5, 5 can be adjusted to match the user's interpupillary distance PD. In particular, when the variable focus lenses 3, 3 are small, as in this embodiment, it is beneficial to be able to adjust the distance between the lenses of the variable focus lenses 3, 3 for each user to match the user's interpupillary distance PD.

[0038] In this embodiment, the distance adjustment section 6b is provided for each of the left and right automatic focusing magnifying glass sections 5, 5, and is formed by grooves formed on the lower surface of the main body case 6a of the magnifying glass body section 6. Each groove extends in the left-right direction along the lower surface of the main body case 6a. Mounting sections 5b (see Figure 2), which are provided on the upper part of the lens holding section 5a of each automatic focusing magnifying glass section 5, 5, are fitted into these grooves and slidably attached.

[0039] In this embodiment, for example, the user can grasp each autofocus magnifying glass unit 5, 5 and move it from side to side, thereby moving each autofocus magnifying glass unit 5, 5 along the grooves in the main body case 6a of the magnifying glass body 6 in the left-right direction. Also, for example, if the user releases their hand from each autofocus magnifying glass unit 5, 5, the static friction force between the mounting portion 5b of each autofocus magnifying glass unit 5, 5 and the groove in the main body case 6a fixes the position of each autofocus magnifying glass unit 5, 5. In this embodiment, the distance between the autofocus magnifying glass units 5, 5 can be adjusted in this way.

[0040] Furthermore, in this embodiment, the mounting portion 5b of each autofocus magnifying glass unit 5, 5 is attached to a groove in the main body case 6a so as to be rotatable around an axis RO that extends perpendicularly to the lower surface of the main body case 6a. Therefore, for example, a user can change the orientation of the optical axis LO of each autofocus magnifying glass unit 5, 5 by gripping the autofocus magnifying glass unit 5, 5 and rotating it around the axis RO. This makes it possible to adjust the convergence angle of the left and right pair of autofocus magnifying glass units 5, 5. If, for example, the user releases their hand from the autofocus magnifying glass unit 5, 5, the rotational position of each autofocus magnifying glass unit 5, 5 is fixed by the static friction force between the mounting portion 5b of the autofocus magnifying glass unit 5, 5 and the groove in the main body case 6a.

[0041] Furthermore, the main body of the magnifying glass 6 is equipped with a control device 10, a battery 20, and a distance detection unit 21.

[0042] As shown in Figure 1, the control device 10 is installed inside the main body case 6a of the magnifying glass body 6, together with the battery 20. The control device 10 can control the focal length of the variable focus lens 3 by controlling the voltage (electrical signal) applied from the battery 20 to each of the second electrodes 302A to 302H of the variable focus lens 3.

[0043] Figure 5 is a block diagram showing the configuration of the control device 10 in this embodiment. The control device 10 in this embodiment includes a main control unit 11, a voltage changing unit 12, an operation unit 13, and a storage unit 14. The control device 10 is connected to the second electrodes 302A to 302H of two variable focus lenses 3, 3, a battery 20 as a power source that supplies voltage, and a distance detection unit 21 that detects the distance to an object that the user views through the auto-focusing magnifying glass units 5, 5.

[0044] The main control unit 11 is constituted by, for example, a control board (computer) on which a CPU, a RAM, a ROM, etc. are mounted, and performs overall control of the binocular loupe 1 by executing a predetermined control program stored in the ROM. In particular, in the present embodiment, the main control unit 11 functions as a control unit (control means) that controls the variable focus lenses 3, 3 so that the focal lengths of the variable focus lenses 3, 3 change based on the viewing distance (detection result) to the viewing object detected by the distance detection unit 21.

[0045] The voltage changing unit 12 changes the voltage applied from the battery 20 to each of the second electrodes 302A to 302H of the variable focus lens 3 under the control of the main control unit 11. The voltage changing unit 12 can change the voltage applied to each of the second electrodes 302A to 302H individually for each of the second electrodes 302A to 302H. However, the voltage changing unit 12 may be capable of partially changing only a part of the second electrodes 302A to 302H (for example, only a pair of second electrodes).

[0046] The operation unit 13 outputs an operation signal indicating the operation content of the user to the main control unit 11 when operated by the user. Examples of the user operations received by the operation unit 13 include, for example, power on / off operations, execution instructions for the main control unit 11, and changes in the control content of the main control unit 11. In particular, the operation unit 13 in the present embodiment receives user operations for changing the focal lengths of the two variable focus lenses 3, 3.

[0047] The operation unit 13 is constituted by an operation device (such as buttons of a mechanical type or an electrostatic touch type, a rotary operation unit such as a dial, etc.) suitable for the content of the user operation received. As shown in FIG. 1, the operation unit 13 of the present embodiment is constituted by two dial units 13a, 13a capable of rotary operation (dial operation) and push operation (button operation).

[0048] As shown in FIG. 1, the dial portions 13a, 13a are provided at both the left and right ends of the loupe main body portion 6, respectively, and are configured to be rotatable about a rotation axis extending in a substantially vertical direction. When the dial portion 13a provided on the left side is rotated in the forward rotation direction, an instruction operation to shorten the focal length of the variable focus lens 3 in the automatic focusing magnifying lens portion ⑤ for the left eye is received. When rotated in the reverse rotation direction, an instruction operation to lengthen the focal length of the variable focus lens 3 in the automatic focusing magnifying lens portion ⑤ for the left eye is received. Further, when the dial portion 13a provided on the right side is rotated in the forward rotation direction, an instruction operation to shorten the focal length of the variable focus lens 3 in the automatic focusing magnifying lens portion ⑤ for the right eye is received. When rotated in the reverse rotation direction, an instruction operation to lengthen the focal length of the variable focus lens 3 in the automatic focusing magnifying lens portion ⑤ for the right eye is received.

[0049] Further, the dial portions 13a, 13a also receive the user's instruction operation by being pushed so as to press their rotation axes inward in the left-right direction. In the present embodiment, the pushing operation on the dial portions 13a, 13a is used for, for example, a switching operation for switching the operation mode of the main control unit 11 or an instruction operation for user determination.

[0050] The switching operation by the pushing operation on the dial portions 13a, 13a is an operation for switching between the setting mode and the use mode. The setting mode is an operation mode for setting the focal length specific information used in the use mode, and sets the user's appropriate focal length according to the visual recognition distance detected by the distance detection unit 21. The use mode is an operation mode for automatically controlling the focal lengths of the variable focus lenses 3, 3 to be the appropriate focal length according to the visual recognition distance detected by the distance detection unit 21.

[0051] The instruction operation for user determination by the pushing operation on the dial portions 13a, 13a is, for example, to search for (measure) the appropriate focal length for the user while changing the focal lengths of the variable focus lenses 3, 3 by rotating the dial portions 13a, 13a, and when the appropriate focal length is determined, perform the instruction operation for determination.

[0052] The memory unit 14 stores programs and data used by the control device 10. In particular, in this embodiment, it stores focal length identification information for determining the focal length of the variable focus lenses 3, 3 according to the distance to the object being viewed, as data used for controlling the focal length of the variable focus lenses 3, 3 in the usage mode.

[0053] The focal length identification information is, for example, information that shows the relationship between the viewing distance to the object being viewed (detection result of the distance detection unit 21) and the respective focal lengths of the two variable focus lenses 3, 3 corresponding to each viewing distance (focal lengths suitable for the user corresponding to each viewing distance). Such information can be stored in the storage unit 14 as table data describing the correspondence between the viewing distance and the focal lengths of the two variable focus lenses 3, 3, as shown in Figure 6, for example.

[0054] In particular, in this embodiment, the focal length identification information includes measurement information that measures the focal lengths (adjusted focal lengths) of the two variable focus lenses 3, 3 that are suitable for the user according to the viewing distance to the object being viewed. This allows the focal lengths of the two variable focus lenses 3, 3 to be adjusted to an appropriate focal length for each user in each usage mode.

[0055] The battery 20 functions as a power source for the control device 10 and outputs a voltage to supply to the second electrodes 302A to 302H of the variable focus lens 3. The battery 20 may be a primary battery or a secondary battery. It may also be equipped with a power generation function such as a solar panel.

[0056] The distance detection unit 21 is not limited in its configuration as long as it can detect the distance to an object that is visible in the area in front of the binocular magnifier 1 (viewing area). In this embodiment, the distance detection unit 21 is located in the left-right center of the main body case 6a of the magnifier body 6, as shown in Figure 1, but it may also be located at the left-right ends of the main body case 6a or at a location away from the main body case 6a (for example, on the eyeglass frame 2). However, it is preferable that the distance detection unit 21 be located in a position where it is less likely to be covered by the user's hair (bangs) when the user wears the binocular magnifier 1.

[0057] The distance measurement method in the distance detection unit 21 is not particularly limited, and existing distance measurement methods such as laser and sound wave methods can be widely adopted. If it is difficult to cover the range of visible distance to be detected by the distance detection unit 21 (from near to far distance) with a single distance detection unit, multiple distance detection units with different effective detection ranges (distance ranges in which high-precision detection is possible) may be arranged.

[0058] Next, an example of focal length control of the variable focus lenses 3, 3 of each automatic focusing magnifying glass unit 5, 5 in this embodiment will be described. Figures 7 and 8 are flowcharts showing the flow of focal length control in this embodiment. However, Figure 7 shows the control content in setting mode, and Figure 8 shows the control content in usage mode. In the focal length control of this embodiment, in usage mode, the main control unit 11, which executes a predetermined control program, controls the voltage change unit 12 to control the focal length of the variable focus lenses 3, 3 based on the viewing distance to the object to be viewed detected by the distance detection unit 21 (detection result) and the focal length identification information in the storage unit 14.

[0059] In this embodiment, when the operation unit 13 receives a power-on operation from the user (S1), it first receives a switching operation to switch the operating mode of the main control unit 11 to either setting mode or usage mode (S2). Specifically, if a press operation is performed on the dial units 13a, 13a within a predetermined time after the power-on operation, the system switches to setting mode (Yes in S2), and if no press operation is performed within the predetermined time, the system switches to usage mode (No in S2). In this example, focal length control is started when the power-on operation is performed, but this is not limited to this. For example, a mounting detection unit may be provided to detect when the binocular loupe 1 is attached to the user, and the system may be configured to start focal length control when it detects that the user has attached the binocular loupe 1.

[0060] When the system switches to setting mode (Yes in S2), the main control unit 11 executes a program for operation in setting mode. In setting mode, the user first rotates the left dial unit 13a while viewing an object at a reference viewing distance (Yes in S3). This sends an operation signal from the operation unit 13 to the main control unit 11, and the main control unit 11 controls the voltage change unit 12 so that a voltage corresponding to this operation signal is applied to the second electrodes 302A to 302H of the variable focus lens 3 (adjustment target lens) of the left eye auto-focusing magnifying glass unit 5. As a result, the curvature of the interface I between the insulating liquid 311 and the conductive liquid 312 in the left eye variable focus lens 3 is changed due to a change in the shape of the interface I, and the focal length of the left eye variable focus lens 3 is changed according to the user's operation on the left dial unit 13a (S4). The user then rotates the left dial unit 13a to adjust the focal length of the left eye variable focus lens 3 so that it is in focus on the object at the reference distance.

[0061] After adjusting the focal length of the variable focus lens 3 in the automatic focusing magnifying glass unit 5 for the left eye, the user then rotates the right dial unit 13a (S5, Yes) while viewing an object at the same reference distance. This sends an operation signal from the operation unit 13 to the main control unit 11, which controls the voltage change unit 12 so that a voltage corresponding to this operation signal is applied to the second electrodes 302A to 302H of the variable focus lens 3 of the automatic focusing magnifying glass unit 5 for the right eye. As a result, the curvature of the interface I between the insulating liquid 311 and the conductive liquid 312 in the variable focus lens 3 for the right eye is changed due to a change in the shape of the interface I, and the focal length of the variable focus lens 3 for the right eye is changed in accordance with the user's operation on the right dial unit 13a (S6). The user then rotates the right dial unit 13a to adjust the focal length of the variable focus lens 3 for the right eye so that it is in focus on an object at the reference distance.

[0062] In this way, after adjusting the focal lengths of the left and right variable focus lenses 3, 3 by rotating the left and right dial sections 13a, 13a so that they are in focus on the object to be viewed at the reference distance, the user performs a push operation (button operation) on the dial sections 13a, 13a (Yes in S7). Upon receiving this operation signal, the main control unit 11 acquires the detection result of the viewing distance detected by the distance detection unit 21 for the object to be viewed at the reference distance (S8). The main control unit 11 then stores the focal lengths of the left and right variable focus lenses 3, 3 at the time the push operation on the dial sections 13a, 13a was performed, and the acquired viewing distance detection result, as focal length identification information in the storage unit 14 (S9).

[0063] For example, if the detection result of the viewing distance detected by the distance detection unit 21 is d10, the main control unit 11 adds d10 as the viewing distance data in the table data shown in Figure 6. The main control unit 11 then stores the user-adjusted focal lengths (adjusted focal lengths), fL10 and fR10, respectively, as the focal lengths of the left and right variable focus lenses 3, 3 corresponding to the viewing distance d10.

[0064] When executing the usage mode, it is desirable to set the user's preferred focal length for a wider range of viewing distances. By repeatedly changing the viewing distance to the object being viewed and performing the setting mode described above, the user can set the user's preferred focal length (fL1, fL6, fL10, fR1, fR6, fR10 in Figure 6) for multiple viewing distances (three points in Figure 6: d1, d6, and d10).

[0065] Next, the operating modes will be explained. If no pressing operation is performed on the dials 13a, 13a within a predetermined time after the power-on operation, or if the setting mode is terminated, the system will switch to the operating mode shown in Figure 8 (S10). When the system switches to the operating mode, the main control unit 11 first calculates an approximate formula, as shown in the graph in Figure 9, from the focal length identification information (for example, the table data shown in Figure 6) stored in the memory unit 14 (S11).

[0066] This approximation formula is an equation that shows the relationship between the viewing distance detected by the distance detection unit 21 and the user's suitable focal length at that viewing distance. As shown in Figure 9, it is an equation that represents the approximation line when the focal length identification information (table data) stored in the storage unit 14 is plotted. For example, the least squares method or the Hough transform can be used to calculate the approximation formula. In this embodiment, the table data used to calculate the approximation formula is stored in the storage unit 14 as focal length identification information, but this approximation formula may also be stored in the storage unit 14 as focal length identification information.

[0067] Once the approximation formula is calculated in this way, the main control unit 11 obtains the detection result of the viewing distance from the distance detection unit 21 to the object to be viewed (S12). Subsequently, the main control unit 11 derives the suitable focal length corresponding to the acquired viewing distance (detection result) using the approximation formula calculated in processing step S11 (S13). Then, the main control unit 11 controls the voltage change unit 12 to change the voltage applied to the second electrodes 302A to 302H of the left and right variable focus lenses 3, 3 so that the focal lengths of the left and right variable focus lenses 3, 3 become the derived suitable focal length. As a result, the focal lengths of the variable focus lenses 3, 3 in each of the left and right automatic focusing magnifying glass units 5, 5 are changed to a focal length suitable for the user (S14), and the object to be viewed is automatically brought into focus.

[0068] In this embodiment, when the operation unit 13 receives a power-off operation from the user (Yes in S15), the main control unit 11 terminates the focal length control. At this time, the voltage supply to each of the second electrodes 302A to 302H of the variable focus lens 3 may be turned off or on. Turning off the voltage supply to each of the second electrodes 302A to 302H of the variable focus lens 3 can save power consumption of the battery 20.

[0069] According to this embodiment, when a user views a relatively close object using the binocular loupe 1, the focal lengths of the variable focus lenses 3, 3 of the left and right automatic focusing magnifying glass units 5, 5 are automatically changed so that the object is in focus. Also, for example, when a user views a relatively distant object using the binocular loupe 1, the focal lengths of the left and right variable focus lenses 3, 3 are automatically changed so that the object is in focus.

[0070] As a specific example, let us consider the use of this binocular loupe 1 as a surgical loupe used by a surgeon, such as a doctor, when performing surgery. In this embodiment, the surgeon wearing the binocular loupe 1 performs surgery while observing (visualizing) magnified images of objects to be viewed, such as the surgeon's hands or the affected area of ​​the patient, through the binocular loupe 1. In addition, during the surgery, the surgeon also needs to view objects at different distances, such as a monitor displaying patient information, surgical assistants, and surgical instruments. With the binocular loupe 1 of this embodiment, even if the surgeon changes their gaze to objects at different distances, the loupe can automatically adjust the surgeon's focus to each object. Therefore, the surgeon can view magnified images of any of the objects at different distances in focus.

[0071] This binocular loupe 1 can be used for a wide range of purposes, not just surgical loupes. For example, it is useful for technicians and craftsmen who handle tiny parts and equipment, medical technologists and nail technicians who perform detailed work, and anyone who uses magnifying glasses for their work.

[0072] In particular, it is preferable that the binocular loupe 1 of this embodiment be a type of wearable device that is worn by the user. Conventional binocular loupes either do not have a changeable focal length, or the range of focal lengths in which the user can focus is narrow, so they cannot focus on other objects that are at a different distance from the target object located at that focal length. Therefore, if the binocular loupe is a type of wearable device that is worn by the user, the user is forced to remove the binocular loupe each time they want to view the other object, and then put the binocular loupe back on when they want to view the target object again, which is a cumbersome process. However, the binocular loupe 1 of this embodiment automatically focuses on any magnified image of objects that are at different distances from each other, so even if it is a type of wearable device that is worn by the user, as in this binocular loupe 1, the user is not forced to perform the cumbersome process of removing and reattaching the binocular loupe.

[0073] In this embodiment, the binocular loupe 1 is an accessory type integrated with the eyeglass frame 2, but it is not limited to this, and may be an attachment type that is attached to the user's eyeglasses. For example, as shown in Figure 10, it may be an attachment type binocular loupe 1' having a mounting part 8 for attaching to the user's eyeglasses 200. This binocular loupe 1' is attached to the eyeglasses 200 by mounting the mounting part 8 to the center of the bridge portion of the user's eyeglasses 200 in the left-right direction. This makes it possible for each user to use the binocular loupe 1' by attaching it to their own eyeglasses 200 that are suited to them.

[0074] Furthermore, although the magnifying glass device according to the present invention has been described using a binocular magnifying glass as an example in this embodiment, it can also be applied to a monocular magnifying glass. In particular, when using the magnifying glass device according to the present invention for viewing objects at a very close distance, a monocular magnifying glass may be more convenient for the user.

[0075] Furthermore, the processing steps and control device components described herein can be implemented by various means. For example, these steps and components may be implemented in hardware, firmware, software, or a combination thereof.

[0076] With respect to hardware implementation, the means such as processing units used to realize the processes and components described above may be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, computers, or combinations thereof.

[0077] Furthermore, with respect to the firmware and / or software implementation, means such as processing units used to realize the aforementioned components may be implemented in the form of a program (e.g., code such as procedures, functions, modules, instructions, etc.) that performs the functions described herein. Generally, any computer / processor-readable medium that clearly embodies the firmware and / or software code may be used to implement means such as processing units used to realize the aforementioned processes and components as described herein. For example, the firmware and / or software code may be stored in memory in a control device, for example, and executed by a computer or processor. That memory may be implemented inside the computer or processor, or it may be implemented outside the processor. Furthermore, the firmware and / or software code may be stored on a computer or processor-readable medium such as, for example, random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), programmable read-only memory (PROM), electrically erasable PROM (EEPROM), flash memory, floppy disks, compact discs (CDs), digital versatile discs (DVDs), magnetic or optical data storage devices, etc. The code may be executed by one or more computers or processors, and the computers or processors may be made to perform functional embodiments described herein.

[0078] Furthermore, the medium may be a non-temporary recording medium. Also, the program code may be readable and executable by a computer, processor, or other device or machine, and its format is not limited to a specific format. For example, the program code may be source code, object code, or binary code, or it may be a mixture of two or more of these codes.

[0079] 1, 1': Binocular magnifier 2: Eyeglass frame 2a: Bridge 2b: Temple 2c: Endpiece 2d: Transparent plate 2e: Holding arm 3: Variable focus lens 4: Magnifying optics 4a: Objective lens 4b: Eyepiece 4c: Lens barrel 5: Auto-focusing magnifier 5a: Lens holder 5b: Mounting part 6: Magnifier body 6a: Body case 6b: Distance adjustment part 8: Mounting part 10: Control device 11: Main control unit 12: Voltage change unit 13: Operation unit 13a: Dial part 14: Memory unit 20: Battery 21: Distance detection unit 200: Eyeglasses

Claims

1. A magnifying glass device comprising: a magnifying optical unit that outputs a magnified image of an object viewed by the user; a distance detection unit that detects the distance to the object; and a focus adjustment unit that adjusts the focus of the magnified image output from the magnifying optical unit based on the detection result of the distance detection unit, wherein the focus adjustment unit comprises: a variable focus lens arranged on the optical path passing through the magnifying optical unit and capable of changing the focal length; and a control unit that controls the focal length of the variable focus lens to a suitable focal length that fits the user's eye based on the detection result of the distance detection unit.

2. The magnifying glass device according to claim 1, wherein the focus adjustment unit has a storage unit that stores focal length identification information for identifying the focal length of the variable focus lens according to the distance to the object to be viewed, and the control unit controls the focal length of the variable focus lens to the appropriate focal length based on the detection result of the distance detection unit and the focal length identification information in the storage unit.

3. A magnifying glass device according to claim 1 or 2, wherein the magnifying optical unit is a magnifying optical system including an objective lens and an eyepiece lens.

4. A magnifying glass device according to claim 1 or 2, wherein the variable focus lens is a shape-variable lens in which the shape of the refractive surface changes and the focal length changes according to an electrical signal controlled by the control unit.

5. A magnifying glass device according to claim 1 or 2, comprising: a pair of left and right automatic focusing magnifying glass units equipped with the magnifying optical unit and the variable focus lens; and a holding unit for holding the pair of left and right automatic focusing magnifying glass units.

6. A magnifying glass device according to claim 5, comprising a distance adjustment unit for adjusting the distance between the left and right pair of automatic focusing magnifying glass units to match the interpupillary distance of the user.

7. The magnifying glass device according to claim 5, wherein the holding portion includes an eyeglass frame.

8. A magnifying glass device according to claim 1 or 2, wherein the magnifying glass device has a mounting portion for attaching to the user's device.

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