Optical device

Abstract

To provide an optical member holding configuration which, even if either one of an eyepiece in contact with ambient atmosphere and a second eyepiece counted from the outside is made of plastic material, prevents surface accuracy and resolution from deteriorating and an image from being deformed, and further inhibits dew condensation caused by intrusion of moisture vapor into the eyepiece.SOLUTION: An optical device of the present invention comprises a second optical member 402 and a first holding member 403. The second optical member includes at its periphery a contact part 402c for tightly contacting a second sealing member 405. The first holding member includes at its periphery a contact part 403c for tightly contacting the second sealing member 405. The first optical member 401 and the first holding member 403 are tightly sealed by a first sealing member 404. A space between the first optical member 401 and the second optical member 402 is tightly sealed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sealing structure for an optical device in which a plurality of optical members are arranged in the optical axis direction, for example, a sealing structure for an optical device constituting a finder unit of a camera body or the like. [Background technology]

[0002] Conventionally, when a camera is moved from a warm indoor environment to a suddenly cold environment, such as in winter, in a cold region, or at night, a temperature difference occurs between the outside temperature and the inside of the camera.

[0003] Therefore, as the temperature inside the eyepiece lens that is in contact with the outside air drops, the amount of saturated water vapor inside the camera decreases, and condensation can form on the inside surface of the eyepiece lens that is in contact with the outside air.

[0004] Furthermore, the camera is turned on in a high humidity, low temperature environment such as rainy weather.

[0005] When the camera is turned on, the temperature inside the camera rises due to heat generated by the integrated circuits on the electrical circuit board and the backlight for the display element inside the viewfinder, and this can also cause condensation to form on the inside of the eyepiece, which is exposed to the outside air.

[0006] In either case, the user cannot wipe the inside of the eyepiece, and condensation can form on the inside of the eyepiece, reducing visibility.

[0007] Condensation can be reduced by preventing water vapor from entering the inside of the eyepiece, which is in contact with the outside air.

[0008] Therefore, as in Patent Document 1, a method has been proposed in which the space between the outermost lens and the second-outermost lens is filled with an adhesive medium to bond the lenses together in a circular shape, thereby preventing water vapor from entering the inside of the eyepiece lens, which is in contact with the outside air. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2021-135354 Summary of the Invention [Problem to be solved by the invention]

[0010] However, in the prior art disclosed in the above-mentioned Patent Document 1, if the eyepiece lens in contact with the outside air and the second lens from the outside are made of glass, there is no effect from shrinkage when the adhesive hardens, and it is possible to glue the entire circumference.

[0011] However, in order to reduce costs and weight, plastic materials are generally used for eyepieces.

[0012] When using plastic for an eyepiece, if the entire circumference is glued together, the lens will deform due to shrinkage when the adhesive hardens, which can lead to problems such as a deterioration in the surface precision of the lens, a decrease in resolution, and image distortion.

[0013] For this reason, when bonding plastic lenses, they are often bonded not all the way around, but in specific areas within the range that will not affect the deterioration of surface accuracy due to deformation of the lens.

[0014] In this case, if at least one of the eyepiece lens that comes into contact with the outside air or the second lens from the outside is made of plastic, it cannot be glued all around.

[0015] Therefore, the conventional technology disclosed in Patent Document 1 cannot be used to prevent water vapor from entering the inside of the eyepiece.

[0016] Therefore, the object of the present invention is to prevent deterioration of surface accuracy, reduction in resolution, image distortion, etc., even if either the eyepiece in contact with the outside air or the second eyepiece from the outside is made of plastic.

[0017] Another object of the present invention is to provide a holding structure for optical members that can prevent condensation due to the intrusion of water vapor into the inside of the eyepiece. [Means for solving the problem]

[0018] In order to achieve the above object, the optical device of the present invention is an optical system having at least two optical members, the optical system including a first optical member in contact with the outside air, a second optical member located inside the first optical member, and a first holding member capable of holding the first optical member and the second optical member; a first sealing member that seals a gap between the first optical member and the first holding member; an optical device having a second sealing member that seals a gap between the first holding member and the second optical member, the second optical member has an abutment portion on an outer periphery thereof for tightly contacting the second sealing member, the first holding member has an abutment portion on an outer periphery thereof for tightly contacting the second sealing member; the first optical member and the first holding member are sealed by a first sealing member, The space between the first optical member and the second optical member is sealed. [Effects of the Invention]

[0019] Even if either the eyepiece in contact with the outside air or the second eyepiece from the outside is made of plastic, there is no deterioration in surface accuracy, reduction in resolution, or image distortion.

[0020] It is also possible to provide a holding structure for optical members that can prevent condensation due to the intrusion of water vapor into the inside of the eyepiece. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of the appearance of a digital camera 100. [Figure 2]FIG. 2 is a cross-sectional view of the eyepiece 16. [Figure 3] FIG. 1 is an exploded perspective view of the eyepiece 16. [Figure 4] FIG. 4 is an exploded perspective view of the lens holding member 409 before the optical member 413 is assembled therein. [Figure 5] FIG. 10 is an exploded perspective view of the lens holding member 409 before the spacer 412 is assembled thereto. [Figure 6] FIG. 4 is an exploded perspective view of a lens holding member 409 before an optical member 408 is assembled therein. [Figure 7] FIG. 10 is an exploded perspective view of the lens holding member 409 before the spacer 411 is assembled therein. [Figure 8] FIG. 10 is an exploded perspective view of a lens holding member 409 before an elastic member 410 is assembled therein. [Figure 9] FIG. 4 is an exploded perspective view of the optical member 401 before it is fixed to the lens holding member 403 by the sealing member 404. [Figure 10] FIG. 4 is an exploded perspective view of the lens holding member 403 before the optical member 402 is assembled therein. [Figure 11] 4 is an exploded perspective view of the lens holding member 403 and the optical member 402 before the gap between the lens holding member 403 and the optical member 402 is sealed with the sealing member 405. FIG. [Figure 12] FIG. 10 is an exploded perspective view of the lens holding member 409 and the lens holding member 403 before they are combined together. DETAILED DESCRIPTION OF THE INVENTION

[0022] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] (Perspective view of the exterior of the digital camera 100) 1A and 1B are perspective views showing the appearance of a digital camera 100 as an example of an optical device to which the present invention can be applied.

[0024] These optical devices may include, for example, mobile phones, game consoles, tablet terminals, personal computers, watch-type or eyeglass-type information terminals, head-mounted displays, and the like.

[0025] It can also be applied to products with an eyepiece (such as monoculars, binoculars, and rangefinders) and eyepiece accessories that attach to the eyepiece (such as rain covers, magnifiers, and angle finders). FIG. 1A is a perspective view of the appearance of the digital camera 100 as seen from the front, and FIG. 1B is a perspective view of the appearance of the digital camera 100 as seen from the back.

[0026] In FIG. 1, the part of the eyecup 802 that comes into contact with the photographer's eye is made of a soft material or the like to prevent light from entering the viewfinder through the gap between the eyepiece frame 801 and the photographer.

[0027] The diopter adjustment dial 900 is a dial for adjusting the position of the EVF module 29 (shown in FIG. 2) described later in accordance with the diopter of the user.

[0028] The eyepiece 16 is a magnifying optical system of an eyepiece finder (a peer-type finder), and the user can view an enlarged image displayed on an internal EVF module 29 through the eyepiece 16.

[0029] The EVF module 29 is a display device such as an LCD or organic EL, and displays an image according to an analog signal from a D / A converter (not shown).

[0030] The display of the EVF module 29 is shorter in the vertical direction than in the horizontal direction when the digital camera 100 is held in the normal position.

[0031] (Eyepiece configuration) Next, the configuration of the eyepiece 16 as the optical device of this embodiment will be described with reference to FIGS.

[0032] FIG. 2 shows a cross-sectional configuration of the eyepiece 16.

[0033] FIG. 3 is an exploded perspective view of the eyepiece 16. FIG. 2 is a vertical cross-sectional view of the eyepiece 16 with the optical axis 1000 of the camera 100 (not shown) at the center when the camera 100 is held in the normal position, with the left side of the figure showing the EVF module 29 side and the right side showing the observer side.

[0034] The eyepiece unit 16 is a magnifying optical system that functions as a viewfinder for a digital camera, a mirrorless camera, a digital video camera, or the like, allowing the photographer to enlarge and observe the image displayed on the EVF module 29, and is provided integrally with or detachably from the imaging device.

[0035] The optical members 402, 408, and 413 are plastic lenses, and the optical member 401 is a flat cover window made of plastic or glass.

[0036] The optical member 402 has a lens shape that is convex toward the optical member 401 side.

[0037] In this embodiment, the optical member 401 is in the shape of a flat plate, but it may also be in the shape of a lens.

[0038] In this embodiment, optical element 402 is convex toward optical element 401, and optical element 401 has a flat plate shape, so that when the space between optical elements 401 and 402 is sealed, the volume can be reduced by inserting the convex lens into the space, as will be described later.

[0039] Furthermore, by shortening the distance between the optical members 401 and 402 near the optical axis 1000, the air layer near the optical axis 1000 is reduced, making it difficult for the central portion into which the user looks when in use to become cloudy.

[0040] Furthermore, since the optical member 401 in contact with the outside air is a flat plate, the temperature of the optical member 401 is less likely to be unevenly distributed, which has the effect of preventing uniform fogging.

[0041] Reference numeral 403 denotes a lens holding member that holds the optical members 401 and 402 , and reference numeral 409 denotes a lens holding member that holds the optical members 408 and 413 .

[0042] Reference numerals 411 and 412 denote spacers for determining the distance between the optical members 413, 408, and 402, and may also function as a mask to prevent unnecessary light from entering the optical members 413, 408, and 402.

[0043] Numeral 410 denotes an elastic member for pressing the optical members 413, 408, 402 and the spacers 412, 411 against the lens holding members 409 and 403, and is made of an elastic material such as silicone rubber.

[0044] Reference numeral 404 denotes a sealing member for sealingly holding the optical member 401 on the lens holding member 403, and in this embodiment, it is a double-sided tape made of a polyolefin foam base material with an acrylic adhesive applied thereto.

[0045] If the optical member 401 is made of glass, the optical member 401 will be resistant to external forces such as deformation.

[0046] Therefore, as long as the gap between the lens holding member 403 and the optical member 401 can be sealed, the adhesive is not limited to double-sided tape, and may be, for example, a UV-curable or anaerobic adhesive.

[0047] The sealing member 404 may also have a masking function to prevent unnecessary light from entering the optical members 402 and 401 .

[0048] Reference numeral 405 denotes a sheet-like sealing member for sealing the optical member 402 and the lens holding member 403 .

[0049] In this embodiment, a single-sided adhesive tape or double-sided tape having an acrylic adhesive applied to a polyolefin foam base material, or a sheet material such as elastic non-adhesive silicone rubber may be used.

[0050] The sealing member 405 may also have a masking function to prevent unnecessary light from entering the optical members 402 and 408. Furthermore, the effectiveness of the sealing members 404 and 405 can be enhanced by using a material with low moisture permeability, such as a polyethylene film, as the base material.

[0051] When the diopter adjustment dial 900 (shown in FIG. 1) is rotated, the EVF module 29 can be moved in the direction of the optical axis 1000 by a cam mechanism (not shown).

[0052] This allows the user to adjust the position of the EVF module 29 to suit their viewing angle.

[0053] In this embodiment, the EVF module 29 is moved by the diopter adjustment dial 900, so that the relative positions of the optical members 401 and 402 do not change even when the user adjusts the diopter.

[0054] The effective optical range of the optical members 401, 402, 408, and 412 is configured to be shorter in the vertical direction than in the horizontal direction when the digital camera 100 is held in the normal position, in accordance with the display of the EVF module 29.

[0055] Next, the detailed configuration of the eyepiece unit 16 will be described in the order of assembly with reference to FIGS.

[0056] (An exploded perspective view of the lens holding member 409 before the optical member 413 is assembled) FIG. 4 is an exploded perspective view of the lens holding member 409 before the optical member 413 is assembled therein.

[0057] Reference numerals 413c1 to 413c6 provided on the outer periphery of the optical member 413 are radial receiving surfaces that determine the positioning in the radial direction with respect to the lens optical axis 1000 (FIG. 2).

[0058] The optical member 413 is positioned in the radial direction so that the optical axis of the optical member 413 is aligned with the optical axis 1000 of the eyepiece 16 by contacting the radial receiving surfaces 409c1 to 409c6 provided on the inner periphery of the lens holding member 409.

[0059] Reference numerals 413 a 1 to 413 a 3 and 413 b 1 to 413 b 3 denote thrust receiving surfaces that determine the position of the optical member 413 in the thrust direction relative to the optical axis 1000 of the eyepiece portion 16 .

[0060] The aforementioned thrust receiving surfaces 413a1 to 413a3, 413b1 to 413b3 are provided on the outer periphery outside the effective optical range of the optical element 413, at three points on each of the front and back of the optical element 413, with the front and back positions being at approximately the same locations when projected in the optical axis direction.

[0061] By holding only the thrust receiving surfaces 413a1 to 413a3 and 413b1 to 413b3 in contact, bending stress is less likely to be applied to the optical member 413, and a deterioration in optical performance due to deformation is less likely to occur.

[0062] These thrust receiving surfaces 413a1 to 413a3 come into contact with thrust receiving surfaces 409a1 to 409a3 provided on the lens holding member 409, so that the position of the optical member 413 in the thrust direction is determined.

[0063] (An exploded perspective view of the lens holding member 409 before the spacer 412 is assembled) FIG. 5 is an exploded perspective view of the lens holding member 409 after the optical member 413 has been assembled therein and before the spacer 412 has been assembled therein.

[0064] The spacer 412 has radial receiving surfaces 412c1 to 412c6 on its outer periphery that determine its position in the radial direction relative to the lens optical axis 1000 (FIG. 2).

[0065] The spacer 412 is positioned in the radial direction so that the optical axis of the spacer 412 is aligned with the optical axis 1000 of the eyepiece 16 by coming into contact with the radial receiving surfaces 409d1 to 409d6 provided on the inner periphery of the lens holding member 409.

[0066] Reference numerals 412a1 to 412a3 and 412b1 to 412b3 denote thrust receiving surfaces that determine the position of the spacer 412 in the thrust direction relative to the optical axis 1000 of the eyepiece unit 16.

[0067] The above-mentioned thrust receiving surfaces 412a1 to 412a3 and 412b1 to 412b3 are provided at three points on each of the front and back surfaces of the spacer 412, with the front and back surfaces positioned at approximately the same locations when projected in the optical axis direction.

[0068] By holding only the thrust receiving surfaces 412a1 to 412a3 and 412b1 to 412b3 in contact with each other, bending stress is less likely to be applied to the spacer 412.

[0069] This makes it possible to prevent the positional accuracy of the thrust receiving surfaces 412a1 to 412a3 and 412b1 to 412b3 from decreasing.

[0070] These thrust receiving surfaces 412a1 to 412a3 come into contact with thrust receiving surfaces 413b1 to 413b3 of the optical member 413, thereby determining the position of the spacer 412 in the thrust direction.

[0071] (An exploded perspective view before the optical member 408 is assembled into the lens holding member 409) FIG. 6 is an exploded perspective view of the lens holding member 409 after the optical member 413 and the spacer 412 have been assembled therein and before the optical member 408 has been assembled therein.

[0072] Reference numerals 408c1 to 408c6 provided on the outer periphery of the optical member 408 are radial receiving surfaces that determine the positioning in the radial direction with respect to the lens optical axis 1000 (FIG. 2).

[0073] The optical member 408 is positioned in the radial direction so that the optical axis of the optical member 408 is aligned with the optical axis 1000 of the eyepiece 16 by contacting the radial receiving surfaces 409f1 to 409f6 provided on the inner periphery of the lens holding member 409.

[0074] Reference numerals 408 a 1 to 408 a 3 and 408 b 1 to 408 b 3 denote thrust receiving surfaces that position the optical member 408 in the thrust direction relative to the optical axis 1000 of the eyepiece portion 16 .

[0075] The aforementioned thrust receiving surfaces 408a1 to 408a3, 408b1 to 408b3 are provided on the outer periphery outside the effective optical range of the optical element 408, at three points on each of the front and back of the optical element 408, with the front and back positions being at approximately the same locations when projected in the optical axis direction.

[0076] By holding only the thrust receiving surfaces 408a1 to 408a3 and 408b1 to 408b3 in contact, bending stress is unlikely to be applied to the optical member 408, and a deterioration in optical performance due to deformation is unlikely to occur.

[0077] These thrust receiving surfaces 408a1 to 408a3 come into contact with thrust receiving surfaces 409e1 to 409e3 provided on the lens holding member 409, so that the position of the optical member 408 in the thrust direction is determined.

[0078] As described above, optical member 413 and optical member 408 are held in contact with lens holding member 409 at different positions.

[0079] This allows each optical element to be corrected separately when tilting of the optical element occurs due to component dimensions and the height of the three thrust receiving surfaces needs to be corrected to correct the tilt.

[0080] (An exploded perspective view of the lens holding member 409 before the spacer 411 is assembled) FIG. 7 is an exploded perspective view of the lens holding member 409 after the optical member 413, the spacer 412, and the optical member 408 have been assembled therein, but before the spacer 411 has been assembled therein.

[0081] The spacer 411 has radial receiving surfaces 411c1 to 411c6 on its outer periphery that determine its position in the radial direction relative to the lens optical axis 1000 (FIG. 2).

[0082] The spacer 411 is positioned in the radial direction so that the optical axis of the spacer 411 is aligned with the optical axis 1000 of the eyepiece 16 by coming into contact with the radial receiving surfaces 409g1 to 409g6 provided on the inner periphery of the lens holding member 409.

[0083] Reference numerals 411a1 to 411a3 and 411b1 to 411b3 denote thrust receiving surfaces that determine the position of the spacer 411 in the thrust direction relative to the optical axis 1000 of the eyepiece unit 16.

[0084] The above-mentioned thrust receiving surfaces 411a1 to 411a3 and 411b1 to 411b3 are provided at three points on each of the front and back surfaces of the spacer 411, with the front and back surfaces positioned at approximately the same locations when projected in the optical axis direction.

[0085] By holding only the thrust receiving surfaces 411a1 to 411a3 and 411b1 to 411b3 in contact with each other, bending stress is less likely to be applied to the spacer 411.

[0086] This makes it possible to prevent the positional accuracy of the thrust receiving surfaces 411a1 to 411a3 and 411b1 to 411b3 from decreasing.

[0087] The thrust receiving surfaces 411a1 to 411a3 come into contact with the thrust receiving surfaces 408b1 to 408b3 of the optical member 408, thereby determining the position of the spacer 411 in the thrust direction.

[0088] (An exploded perspective view of the lens holding member 409 before the elastic member 410 is assembled) FIG. 8 is an exploded perspective view of the lens holding member 409 after the optical member 413, the spacer 412, the optical member 408, and the spacer 411 are assembled therein, but before the elastic member 410 is assembled therein.

[0089] The elastic member 410 is provided with thrust receiving surfaces 410a1 to 410a3 and 410b1 to 410b3.

[0090] The surfaces 410a1 to 410a3 come into contact with the thrust receiving surfaces 412b1 to 412b3 of the spacer 412, and the surfaces 410b1 to 410b3 come into contact with the thrust receiving surfaces 411b1 to 411b3 of the spacer 411.

[0091] Furthermore, as will be described later, the sealing member 405 and the elastic member 410 come into contact with each other, and the elastic member 410 is compressed.

[0092] Therefore, an elastic force is generated, which urges the optical member 413 toward the lens holding member 409 via the spacer 412 , and urges the optical member 408 toward the lens holding member 409 via the spacer 411 .

[0093] Therefore, the optical member 402 is biased against the lens holding member 403 via the sealing member 405 to stabilize the thrust position of each optical member.

[0094] (An exploded perspective view of the optical member 401 before it is fixed by the sealing member 404) FIG. 9 is an exploded perspective view of the optical member 401 before it is fixed to the lens holding member 403 by the sealing member 404. FIG.

[0095] The sealing member 404 is made of double-sided tape with adhesive on both sides, and is sandwiched between the lens holding member 403 and the optical member 401 to seal the gap between the opening 403c of the lens holding member 403 and the optical member 401. In this embodiment, the sealing member 404 is made of double-sided tape.

[0096] However, if the optical element 401 is a glass lens whose optical performance is not affected by distortion due to shrinkage of the adhesive, this configuration is not necessary, and the entire periphery may be sealed with adhesive or the like.

[0097] (An exploded perspective view before the optical member 402 is assembled into the lens holding member 403) FIG. 10 is an exploded perspective view after the optical member 401 is sealed and fixed to the lens holding member 403 but before the optical member 402 is assembled.

[0098] The optical member 402 has radial receiving surfaces 402b1 to 402b6 provided on its outer periphery for positioning in the radial direction relative to the lens optical axis 1000 (FIG. 2).

[0099] The optical member 402 is positioned in the radial direction so that the optical axis of the optical member 402 is aligned with the optical axis 1000 of the eyepiece 16 by contacting the radial receiving surfaces 403b1 to 403b6 provided on the inner periphery of the lens holding member 403.

[0100] Reference numerals 402 a 1 to 402 a 3 denote thrust receiving surfaces that determine the position of the optical member 402 in the thrust direction relative to the optical axis 1000 of the eyepiece portion 16 .

[0101] These thrust receiving surfaces 402a1 to 402a3 come into contact with thrust receiving surfaces 403a1 to 403a3 of the lens holding member 403, thereby determining the position of the optical member 402 in the thrust direction.

[0102] (An exploded perspective view before sealing with the sealing member 405) FIG. 11 is an exploded perspective view of the lens holding member 403 and the optical member 402 before the gap between them is sealed with the sheet-like sealing member 405. FIG.

[0103] A flat portion 402c is provided on the outer periphery of the optical member 402 outside the effective optical range, on a surface perpendicular to the optical axis 1000.

[0104] Furthermore, the lens holding member 403 has a flat portion 403 c on a surface perpendicular to the optical axis 1000 on the outer periphery of the optical member 402 when the optical member 402 is incorporated into the lens holding member 403 .

[0105] When the optical member 402 is assembled into the lens holding member 403, the two flat surfaces 402c and 403c are at approximately the same height.

[0106] The surface of the sealing member 405 facing the optical member 402 is made of adhesive.

[0107] Therefore, by attaching the lens holding member 403 and the optical member 402 to each other without any gaps, the lens holding member 403 and the optical member 402 are sealed together.

[0108] With this configuration, the plastic optical member 402, which is easily deformed by external forces, can be sealed without applying a load that would cause deformation.

[0109] In this way, only the optical member 401 in contact with the outside air and the second optical member 402 are made into the optical member holding member 403 separate from the optical member holding member 409 .

[0110] This makes it easy to attach sheet-like sealing member 405 to flat portions 402c and 403c, which are at approximately the same height, when optical member 402 is incorporated into lens holding member 403.

[0111] (An exploded perspective view of the lens holding member 403 with the optical members 401 and 402 sealed and fixed thereto before being combined.) FIG. 12 is an exploded perspective view showing a state in which optical member 413, spacer 412, optical member 408, spacer 411, and elastic member 410 are assembled into lens holding member 409, and a state in which optical members 401 and 402 are sealed and fixed to lens holding member 403, before they are combined.

[0112] The position in the radial direction is determined by the positioning pin 409h of the lens holding member 409 and the positioning hole 403d of the lens holding member 403.

[0113] Furthermore, flat surface 409j of lens holding member 409 and flat surface 403e of lens holding member 403 (FIG. 11) come into contact with each other to determine the position in the thrust direction, and the two lens holding members are fixed together by screws 414.

[0114] At this time, the sealing member 405 and the elastic member 410 come into contact with each other, and the elastic member 410 is compressed, generating an elastic force.

[0115] As a result, the optical member 413 is biased toward the lens holding member 409 via the spacer 412 , and the optical member 408 is biased toward the lens holding member 409 via the spacer 411 .

[0116] The optical members 402 are biased against the lens holding member 403 via the sealing member 405 to stabilize the thrust positions of the optical members.

[0117] Furthermore, the elastic member 410 biases the sealing member 405 against both the optical member 402 and the lens holding member 403, thereby providing a stronger seal.

[0118] In this embodiment, the optical members 413 and 408 are configured to be biased toward the lens holding member 403 using the elastic member 410 via the spacers 411 and 412, but the elastic member 410 may also be configured to be biased by directly contacting the optical member 413 or the optical member 408.

[0119] With the above configuration, the space between optical member 401 and optical member 402 is sealed by sealing member 404, lens holding member 403, and sheet-like sealing member 405. This makes it possible to prevent water vapor from entering from the outside.

[0120] Therefore, the inner surface of the optical member 401 is less likely to become humid, and even if the temperature of the inner surface of the optical member 401 drops due to the influence of the outside air, the amount of water vapor in the sealed space is less likely to exceed the saturated water vapor amount, making it less likely to fog up.

[0121] Furthermore, only the space between optical members 401 and 402 is sealed, which makes it possible to reduce the absolute amount of water vapor present in the sealed space.

[0122] As a result, the temperature on the inner surface side of the optical member 401 drops due to the influence of the outside air, and even if the amount of water vapor in the sealed space exceeds the saturated amount of water vapor, fogging can be kept to a minimum.

[0123] Furthermore, since optical member 402 is convex toward optical member 401 and optical member 401 has a flat plate shape, when the space between optical members 401 and 402 is sealed, the volume can be reduced by inserting the convex lens into the space.

[0124] Furthermore, by making the distance L (shown in Figure 2) between the optical elements 401 and 402 near the optical axis 1000 shorter than the thickness t (shown in Figure 2) of the optical element 401, the air layer near the optical axis 1000 is reduced, which has the effect of making it less likely for the center, which the user looks into, to become cloudy during use.

[0125] Furthermore, the optical member 401 that is in contact with the outside air is a flat plate, which makes it difficult for the temperature of the optical member 401 to become uneven, and has the effect of preventing uniform fogging.

[0126] Furthermore, even if at least one of the optical member 401 in contact with the outside air and the second optical member 402 from the outside is made of plastic, the sheet-like sealing member 405 can seal the lens without applying a load to it.

[0127] Therefore, condensation can be prevented without adversely affecting surface accuracy, resolution, or image distortion.

[0128] The features of this embodiment are summarized below.

[0129] The first feature is shown in FIG.

[0130] The optical device has an optical system having at least two optical members, including a first optical member 401 that is in contact with the outside air and a second optical member 402 that is located inside the first optical member 401.

[0131] The optical device also has a first holding member 403 capable of holding the first optical member 401 and the second optical member 402, and a first sealing member 404 that seals the gap between the first optical member 401 and the first holding member 403.

[0132] The optical device also includes a second sealing member 405 that seals the gap between the first holding member 403 and the second optical member 402 .

[0133] The second optical member 402 has an abutment portion 402c on its outer periphery to which the second sealing member 405 is tightly attached, and the first holding member 403 has an abutment portion 403c on its outer periphery to which the second sealing member 405 is tightly attached.

[0134] The first optical member 401 and the first holding member 403 are sealed by a first sealing member 404, and the space between the first optical member 401 and the second optical member 402 is sealed.

[0135] The second feature will be explained using Figures 2 and 3.

[0136] The first optical member 401 is characterized by being a flat plate.

[0137] The third feature will be explained using Figures 2 and 3.

[0138] The second optical member 402 is characterized by being made of plastic.

[0139] The fourth feature is shown in FIG.

[0140] The second optical member 402 is characterized by being a lens having a convex shape facing the first optical member 401 .

[0141] The fifth feature is illustrated using FIG.

[0142] The distance between the first optical member 401 and the second optical member 402 on the optical axis is shorter than the thickness of the first optical member 401 .

[0143] The sixth feature will be illustrated using FIG.

[0144] The first sealing member 404 is characterized by being a double-sided tape.

[0145] The seventh feature is illustrated using FIG.

[0146] The first sealing member 404 is characterized by being an adhesive.

[0147] The eighth feature will be explained using Figs. 2 and 9.

[0148] One of the first sealing member 404 and the second sealing member 405 also serves as a mask that limits the optical path.

[0149] The ninth feature is illustrated in FIG.

[0150] Further, an electronic display device 29 is provided, The first optical member 401 and the second optical member 402 constitute a magnifying optical system for magnifying and observing the electronic display device 29.

[0151] The tenth feature is shown in FIG.

[0152] The optically effective ranges of the first optical member 401 and the second optical member 402 are characterized in that the vertical direction is shorter than the horizontal direction.

[0153] The eleventh feature is illustrated using FIG.

[0154] Further, a diopter adjusting means 900 for adjusting the diopter of the electronic display device 29 is provided. The diopter adjustment means 900 is characterized in that the diopter can be adjusted by moving the position of the electronic display device 29 in the optical axis direction.

[0155] The twelfth feature is illustrated using Figure 1.

[0156] When the diopter is adjusted by the diopter adjusting means 900, the relative positional relationship between the first optical member 401 and the second optical member 402 does not change.

[0157] The thirteenth feature is illustrated using Figure 2.

[0158] Furthermore, the optical element 401 includes a third optical element 408 arranged inside the second optical element 402, a second holding element 409 that holds the third optical element 408, and a biasing element 410 that biases the first holding element 403 toward the second holding element 409.

[0159] The second sealing member 405 and the biasing member 410 come into contact with each other, and the biasing member 410 is compressed, thereby biasing the first holding member 403 against the second holding member 409, thereby determining the position in the optical axis direction.

[0160] The fourteenth feature is illustrated using Figure 2.

[0161] The contact portion of the second optical member 402 is a flat portion 402c to which the second sealing member 405 is brought into close contact.

[0162] The contact portion of the first holding member 403 is a flat portion 403c to which the second sealing member 405 is brought into close contact.

[0163] Next, combinations of embodiments included in the present invention will be shown.

[0164] (Configuration 1) Among the optical systems having at least two optical members, a first optical member 401 that is in contact with the outside air and a second optical member 402 that is located inside the first optical member 401; a first holding member 403 capable of holding the first optical member 401 and the second optical member 402; a first sealing member 404 that seals the gap between the first optical member 401 and the first holding member 403; an optical device having a second sealing member 405 that seals a gap between the first holding member 403 and the second optical member 402, The second optical member 402 has a contact portion 402c on its outer periphery to which the second sealing member 405 is tightly attached, The first holding member 403 has a contact portion 403c on its outer periphery that tightly contacts the second sealing member 405, The first optical member 401 and the first holding member 403 are sealed by a first sealing member 404, An optical device characterized in that the space between the first optical member 401 and the second optical member 402 is sealed.

[0165] (Configuration 2) 2. The optical device according to configuration 1, wherein the first optical member 401 is a flat plate.

[0166] (Configuration 3) 3. The optical device according to configuration 1 or 2, wherein the second optical member 402 is made of plastic.

[0167] (Configuration 4) 4. The optical device according to any one of configurations 1 to 3, wherein the second optical member 402 is a lens having a convex shape facing the first optical member 401.

[0168] (Configuration 5) The optical device according to any one of configurations 2 to 4, wherein the distance on the optical axis between the first optical member 401 and the second optical member 402 is shorter than the thickness of the first optical member 401.

[0169] (Configuration 6) 6. The optical device according to any one of configurations 1 to 5, wherein the first sealing member 404 is a double-sided tape.

[0170] (Configuration 7) 7. The optical device of any one of configurations 1 to 6, wherein the first sealing member 404 is an adhesive.

[0171] (Configuration 8) 8. The optical device according to any one of configurations 1 to 7, wherein one of the first sealing member 404 and the second sealing member 405 also serves as a mask that limits the optical path.

[0172] (Configuration 9) Further, an electronic display device 29 is provided, The optical device described in any one of configurations 1 to 8, characterized in that the first optical member 401 and the second optical member 402 constitute a magnifying optical system for magnifying and observing the electronic display device 29.

[0173] (Configuration 10) 10. The optical device according to any one of configurations 1 to 9, wherein the optical effective ranges of the first optical member 401 and the second optical member 402 are shorter in the vertical direction than in the horizontal direction.

[0174] (Configuration 11) Further, a diopter adjusting means 900 for adjusting the diopter of the electronic display device 29 is provided. 10. The optical device according to configuration 9, wherein the diopter adjustment means 900 moves the position of the electronic display device 29 in the optical axis direction, thereby adjusting the diopter.

[0175] (Configuration 12) 12. The optical device according to configuration 11, wherein when the diopter is adjusted by the diopter adjusting means 900, the relative positional relationship between the first optical member 401 and the second optical member 402 remains unchanged.

[0176] (Configuration 13) The optical system further includes a third optical member 408 disposed inside the second optical member 402, a second holding member 409 that holds the third optical member 408, and a biasing member 410 that biases the first holding member 403 toward the second holding member 409, The optical device described in any one of configurations 1 to 12, characterized in that the second sealing member 405 and the biasing member 410 come into contact with each other, and the biasing member 410 is compressed, thereby biasing the first holding member 403 against the second holding member 409, thereby determining the position in the optical axis direction.

[0177] (Configuration 14) The contact portion of the second optical member 402 is a flat portion 402c that tightly contacts the second sealing member 405, 14. The optical device according to any one of configurations 1 to 13, wherein the contact portion of the first holding member 403 is a flat portion 403c that brings the second sealing member 405 into close contact.

[0178] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0179] 29 EVF module 401 Optical Components 402 Optical Components 402c Optical component flat surface 403 Lens holding member 403c Flat surface of holding member 404 Sealing members 405 Sealing member 408 Optical Components 409 Lens holding member 410 Elastic member 411 Spacer 412 Spacer 413 Optical Components 900 Diopter adjustment dial

Claims

1. An optical system having at least two optical members, a first optical member in contact with the outside air, and a second optical member located inside the first optical member; a first holding member capable of holding the first optical member and the second optical member; a first sealing member that seals a gap between the first optical member and the first holding member; an optical device having a second sealing member that seals a gap between the first holding member and the second optical member, the second optical member has an abutment portion on an outer periphery thereof for tightly contacting the second sealing member, the first holding member has an abutment portion on an outer periphery thereof for tightly contacting the second sealing member; the first optical member and the first holding member are sealed by a first sealing member, An optical device, wherein a space between the first optical member and the second optical member is sealed.

2. 2. The optical device according to claim 1, wherein the first optical member is a flat plate.

3. 2. The optical device according to claim 1, wherein the second optical member is made of plastic.

4. 2. The optical device according to claim 1, wherein the second optical member is a lens having a convex shape facing the first optical member.

5. 3. The optical device according to claim 2, wherein the distance between the first optical member and the second optical member on the optical axis is shorter than the thickness of the first optical member.

6. 2. The optical device according to claim 1, wherein the first sealing member is a double-sided tape.

7. 2. The optical device of claim 1, wherein the first sealing member is an adhesive.

8. 2. The optical device according to claim 1, wherein one of the first sealing member and the second sealing member also serves as a mask that defines an optical path.

9. Further, an electronic display device is provided, 2. The optical device according to claim 1, wherein the first optical member and the second optical member constitute a magnifying optical system for magnifying and observing the electronic display device.

10. 2. The optical device according to claim 1, wherein the optical effective ranges of the first optical member and the second optical member are shorter in the vertical direction than in the horizontal direction.

11. Further, a diopter adjusting means for adjusting the diopter of the electronic display device is provided, 10. The optical device according to claim 9, wherein the diopter adjustment means moves the position of the electronic display device in the optical axis direction, thereby adjusting the diopter.

12. 12. The optical device according to claim 11, wherein when the diopter is adjusted by the diopter adjusting means, the relative positional relationship between the first optical member and the second optical member does not change.

13. The optical system further includes a third optical member disposed inside the second optical member, a second holding member that holds the third optical member, and a biasing member that biases the first holding member toward the second holding member, The optical device according to claim 1, wherein the second sealing member and the biasing member come into contact with each other and compress the biasing member, thereby biasing the first holding member against the second holding member and determining the position in the optical axis direction.

14. the abutment portion of the second optical member is a flat portion that tightly contacts the second sealing member, 2. The optical device according to claim 1, wherein the abutting portion of the first holding member is a flat portion 4 that tightly contacts the second sealing member.

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