Virtual image display device and optical unit

Abstract

In an optical system comprising a lens barrel containing a lens element and a polarization control element, the position of the polarization control element relative to the lens barrel is adjustable, and the inside of the lens barrel is sealed to ensure image quality. [Solution] The virtual image display device comprises a lens barrel having a first aperture into which image light is incident, a first lens fixed inside the lens barrel, a sealing member fixed to the first aperture and sealing the first aperture, and an image display panel fixed outside the lens barrel and generating image light that is emitted toward the first lens via the sealing member, wherein the sealing member includes a polarization control member that converts the image light into a predetermined polarization.

Description

Technical Field

[0001] The present invention relates to a virtual image display device and an optical unit that enable observation of a virtual image, and particularly to a virtual image display device and an optical unit that use a lens barrel having a built-in lens and sealed from the outside.

Background Art

[0002] There is known a system including a central mounting portion, a rotating collar connected to the central mounting portion and configured to rotate around the central mounting portion, and two or more holding prongs attached to the rotating collar. The rotating collar is configured to hold a first lens while rotating the first lens around the optical axis of a pancake lens display assembly including a second lens optically in series with the first lens. The rotating collar rotates the first lens to position the first orientation axis of a quarter-wave plate on the first lens at an angle with respect to the second orientation axis of a reflective polarizer on the second lens. The angle is such that light transmitted through the second lens and then the first lens is substantially circularly polarized. The system also includes an irradiation source configured to emit test light through the first lens and the second lens, and a sensor configured to receive the test light emitted by the irradiation source (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the system described above, the lens surface of the first lens on the panel side is sealed together with the panel by the lens barrel part. In this structure, since the pancake lens portion is not sealed, foreign matter leaking from inside the pancake lens or from the sealing portion of the panel and lens barrel may adhere to the lens surface on the panel side or the panel surface, and such adhesion can lead to a deterioration of image quality. In order to improve the quality of the HMD (Head Mounted Display) image during panel assembly, it may be necessary to adjust the rotation angle of the polarizing element bonded to the panel surface to match the rotation direction of the pancake lens, or to adjust the position in the optical axis direction, horizontal direction, and rotation direction for focusing the displayed image, but there is a risk of interference with the lens barrel part, so there are limits to the range of various adjustments. As a result, it may not be possible to adjust the position of the panel sufficiently, and it may not be possible to assemble the system while ensuring sufficient image quality. [Means for solving the problem]

[0005] A virtual image display device in one aspect of the present invention comprises a lens barrel having a first aperture into which image light is incident, a first lens fixed inside the lens barrel, a sealing member fixed to the first aperture and sealing the first aperture, and an image display panel fixed outside the lens barrel and generating image light that is emitted toward the first lens via the sealing member, wherein the sealing member includes a polarization control member that converts the image light into a predetermined polarization.

[0006] An optical unit in one aspect of the present invention comprises a lens barrel having a first aperture into which image light is incident, a first lens fixed inside the lens barrel, a sealing member fixed to the first aperture and sealing the first aperture, and an image display panel fixed outside the lens barrel and generating image light that is emitted toward the first lens via the sealing member, wherein the sealing member includes a polarization control member that converts the image light into a predetermined polarization. [Brief explanation of the drawing]

[0007] [Figure 1] This is an external front view illustrating the mounting state of the virtual image display device according to the first embodiment. [Figure 2] This is a lateral cross-sectional view illustrating the internal structure of the display optical system. [Figure 3] This is a partial cross-sectional view illustrating the detailed structure of a part of the display optical system. [Figure 4] This is a conceptual diagram illustrating the optical operation of the virtual image display device according to the first embodiment. [Figure 5] This is a perspective cross-sectional view illustrating the structure of the lens barrel of the first embodiment. [Figure 6] This is a perspective cross-sectional view illustrating the structure of the lens barrel of the first embodiment. [Figure 7] This is a partial cross-sectional view illustrating the structure of the lens barrel of the first embodiment. [Figure 8] This is a conceptual diagram illustrating the optical operation of a modified virtual image display device. [Figure 9] This is a side cross-sectional view illustrating the internal structure of the virtual image display device of the second embodiment. [Figure 10] This is a partial cross-sectional view illustrating the detailed structure of a part of the display optical system. [Figure 11] This is a conceptual diagram illustrating the optical operation of the virtual image display device according to the second embodiment. [Figure 12] This is a conceptual diagram illustrating the optical operation of a modified virtual image display device. [Modes for carrying out the invention]

[0008] [First Embodiment] The following describes a virtual image display device according to one embodiment of the present invention with reference to Figures 1 to 7.

[0009] Figure 1 is a perspective view illustrating the wearing state of a head-mounted display, i.e., a head-mounted display device 200. The head-mounted display device (hereinafter also referred to as HMD) 200 causes the observer or wearer US to perceive an image as a virtual image. In Figure 1, etc., X, Y, and Z are Cartesian coordinate systems, the +X direction corresponds to the lateral direction in which the binocular eyes (EY) of the observer or wearer US wearing the HMD 200 are aligned, the +Y direction corresponds to the upward direction perpendicular to the lateral direction in which the binocular eyes (EY) are aligned for the wearer US, and the +Z direction corresponds to the forward or frontal direction for the wearer US. The ±Y directions are parallel to the vertical axis or the vertical direction.

[0010] The HMD200 comprises a first virtual image display device 100A for the right eye, a second virtual image display device 100B for the left eye, a pair of temples 100C that support the virtual image display devices 100A and 100B, and a user terminal 90 which is an information terminal. The first virtual image display device 100A consists of a first display drive unit 102a located at the top and a first display optical system 103a that covers the area in front of the eyes. The second virtual image display device 100B consists of a second display drive unit 102b located at the top and a second display optical system 103b that covers the area in front of the eyes. The HMD200, which combines the first virtual image display device 100A and the second virtual image display device 100B, is also a virtual image display device in a broad sense. The pair of temples 100C support the upper ends of the pair of display optical systems 103a and 103b via the display drive units 102a and 102b, which are integrated externally. The combination of the pair of display drive units 102a and 102b is called the drive unit 102.

[0011] Figure 2 is a conceptual lateral cross-sectional view illustrating the structure of the first display optical system 103a. Figure 3 is a partial cross-sectional view illustrating the detailed structure of a part of the first display optical system 103a. Figure 3 includes regions AR1, AR2, and AR3. Regions AR1, AR2, and AR3 in Figure 3 are enlarged versions of the structures of regions AR1, AR2, and AR3 shown in Figure 2, respectively. The first display optical system 103a comprises a display unit 10 that emits circularly polarized image light ML, an optical element 20 that refracts the image light ML twice to form a virtual image, and a circuit element 80 that controls the operation of the display unit 10 and the like.

[0012] In the first virtual image display device 100A, the optical device (specifically, the display 10 and the optical member 20) excluding the circuit member 80 is referred to as an optical unit 100.

[0013] Although detailed description is omitted, the second display optical system 103b is optically identical to the first display optical system 103a or is obtained by horizontally inverting the first display optical system 103a. Hereinafter, the first display optical system 103a will be described, and the description of the second display optical system 103b will be omitted.

[0014] In the first display optical system 103a, the display 10 includes an image display panel 11 which is a self-luminous type image light generation device, and a polarization control member PC1 which converts the video light ML emitted from the image display panel 11 into circular polarization. A cover glass 11c for protecting the image display panel 11 may be disposed between the image display panel 11 and the polarization control member PC1. As shown in the region AR2 of FIG. 3, the cover glass 11c and the polarization control member PC1 are separated from each other.

[0015] The image display panel 11 is, for example, an OLED (Organic Light Emitting Diode) display, and forms a monochrome or color still image or moving image on a two-dimensional display surface 11d. The video light ML emitted from the image display panel 11 includes random polarization. The image display panel 11 is driven by the circuit member 80 to perform a display operation. The image display panel 11 is not limited to an OLED display, and can be replaced with a display device using an inorganic EL, an organic LED, a LED array, a laser array, a quantum dot light emitting type element, or the like.

[0016] The image display panel 11 is not limited to a self-luminous type video light generation device, and may be composed of an LCD (Liquid Crystal Display) or other light modulation elements, and generate an image by illuminating the light modulation element with a light source such as a background.

[0017] The polarization control member PC1 has a circular polarizing plate 13. As an example, the circular polarizing plate 13 may be a thin film-like circular polarizing element. The thickness of the film-like circular polarizing element may be about 0.2 mm. Also, as an example, the circular polarizing plate 13 may be supported by being attached onto a transparent support plate SP or the like.

[0018] The optical member 20 includes, in order from the image display panel 11 side, a polarization control member PC2, a lens member 21, and a polarization control member PC3. The lens member 21 is fixed inside the lens barrel 30. Thus, the optical member 20 is disposed inside the lens barrel 30.

[0019] The number of lens sheets constituting the imaging optical member 20 is one, and the configuration is optically very simple. Also, since it can be constituted by one lens, the number of parts is simply small, and furthermore, since the process of bonding lenses is unnecessary, the cost can be significantly reduced compared to the conventional configuration. From this, the weight of the entire optical system can be made very light.

[0020] As shown in the region AR2 of FIG. 3, in the optical member 20, the polarization control member PC2 has a reflective optical element 22. As shown in the region AR1 of FIG. 3, the polarization control member PC3 has, in order from the lens member 21 side toward the -Z direction, a polarization conversion member 224 and a reflective polarization optical element 25.

[0021] In the polarization control member PC2, the reflective optical element 22 is a transmissive mirror HM, which partially transmits and partially reflects the video light ML. The reflective optical element 22 covers the pupil position PP where the eye EY or the pupil is disposed and has a concave shape toward the pupil position PP and a convex shape toward the outside world. The reflectance of the reflective optical element 22 with respect to the video light ML is, for example, about 50% from the viewpoint of ensuring the luminance of the video light ML, but it is not limited to this. The reflective optical element 22 is a single-layer or multilayer film of a metal such as Al or Ag with an adjusted film thickness. The reflective optical element 22 can be formed, for example, by lamination using vapor deposition, but can also be formed by attaching a sheet-like reflective film.

[0022] The lens member 21 is a positive-power convex-concave pancake lens and has a first optical surface 21a on the incident side and a second optical surface 21b on the exit side. The first optical surface 21a and the second optical surface 21b are curved surfaces, specifically spherical or aspherical. The lens member 21 is formed of, for example, resin, but can also be made of glass. Making the lens member 21 of glass is advantageous from the viewpoint of miniaturization. The reflective optical element 22 is provided opposite the first optical surface 21a, and more specifically, is formed directly on the first optical surface 21a. In other words, the first optical surface 21a and the reflective optical element 22 have the same shape, but the first optical surface 21a functions as a convex refractive surface, and the reflective optical element 22 functions as a concave reflective surface. On the other hand, the polarizing optical element 25 is provided opposite the second optical surface 21b, and more specifically, is formed on the second optical surface 21b via a thin film polarization conversion member 224. In other words, the second optical surface 21b and the polarizing optical element 25 have the same shape, but the second optical surface 21b functions as a concave refractive surface, and the polarizing optical element 25 functions as a convex reflective surface.

[0023] In the polarization control member PC3, the polarization conversion member 224 converts the circularly polarized light that has passed through the lens member 21 into a first linearly polarized light L1 in a first polarization direction corresponding to the vertical or Y direction (see Figure 4). The polarization conversion member 224 is formed of a liquid crystal material, such as a photocrosslinkable polymer liquid crystal material. As another example, the polarization conversion member 224 may be a film-like quarter-wave plate.

[0024] A brief explanation of the fabrication of the polarization conversion member 224 is provided. For example, a photocrosslinkable polymer liquid crystal material is applied to a flexible transparent resin substrate to form a photocrosslinkable polymer liquid crystal material layer, i.e., a thin film. By irradiating this thin film of photocrosslinkable polymer liquid crystal material with linearly polarized ultraviolet light whose polarization direction is controlled, the orientation state of rod-shaped molecular species (i.e., molecules with refractive index differences between their major and minor axes) that exhibit liquid crystal properties can be controlled while curing the thin film of photocrosslinkable polymer liquid crystal material. In this case, among the molecular species that exhibit liquid crystal properties due to ultraviolet light, molecular species that extend in a direction matching the polarization direction of the ultraviolet light crosslink, and their orientation state is fixed in the same direction as the polarization direction. Here, a concave lens or container with a spherical surface is prepared, the photocrosslinkable polymer liquid crystal material is applied to the surface of the concave lens or container, and by using an appropriate optical system, spherical wave ultraviolet light with a wavefront of the same curvature as the surface is irradiated onto the photocrosslinkable polymer liquid crystal material, thereby fixing the orientation state so that the polarization direction is along the surface. After ultraviolet irradiation, the thin film of photocrosslinkable polymer liquid crystal material is annealed. This process allows for the liquid crystalline transformation of molecular species exhibiting liquid crystallinity that did not change orientation due to ultraviolet light, and aligns their orientation with that of the polymer portion already in the desired orientation. Subsequent cooling then fixes the orientation. In other words, a waveplate is obtained made of a thin film in which the orientation directions of most of the liquid crystalline molecular species constituting the photocrosslinkable polymer liquid crystal material are aligned. The retardation of such a waveplate can be adjusted by adjusting its thickness. The polarization conversion member 224 obtained in this way is fixed to the lens member 21, for example, by being attached to the second optical surface 21b using an adhesive. In the above description, the polarization conversion member 224 is formed by coating the photocrosslinkable polymer liquid crystal material onto a transparent resin substrate, but the polarization conversion member 224 may also be formed directly by coating it onto the optical surfaces 21a and 21b of the lens member 21.

[0025] Liquid crystal optical materials such as the polarization conversion member 224 can also be manufactured by the method for manufacturing liquid crystal optical materials described in Japanese Patent Publication No. 2008-501147. Furthermore, liquid crystal optical materials such as the polarization conversion member 224 can also be manufactured by the method described at https: / / www.jstage.jst.go.jp / article / oubutsu1932 / 70 / 9 / 70_9_1078 / _pdf.

[0026] The polarizing optical element 25 is a wire grid polarizer that selectively reflects the first linear polarization L1 in the first polarization direction corresponding to the vertical or Y direction, and selectively transmits only the second vertical polarization L2 in the second polarization direction corresponding to the horizontal X direction (see Figure 4). The polarizing optical element 25 has a structure in which a large number of metal fine wires made of aluminum, nickel, etc. are arranged in parallel on a flexible transparent resin substrate, and this wire grid layer made of a large number of metal fine wires is covered with a transparent protective layer. The polarizing optical element 25 reflects linear polarization having an electric field component (corresponding to the polarization direction) that is parallel to the direction in which the large number of metal fine wires extend and perpendicular to the periodic direction corresponding to the arrangement direction. The body of the polarizing optical element 25 is manufactured by transferring the uneven shape to the surface of a resin film made of UV resin or thermoplastic resin using a mold with an uneven structure, and then depositing aluminum from an oblique direction onto the tops and sides of the convex parts of the uneven shape using a vacuum deposition method. The body of the polarizing optical element 25 can also be manufactured by applying a polymer solution to a mold having an uneven structure using a spin coating method, and then curing the polymer solution formed on the mold surface (see, for example, Japanese Patent Application Publication No. 2011-221334). The polarizing optical element 25 obtained in this way is fixed to the lens member 21 by, for example, attaching it to the polarizing conversion member 224 using an adhesive.

[0027] The polarizing optical element 25 does not have to be a wire grid polarizer; for example, it may be a polarizer of the type in which multiple films with anisotropy created by rolling are laminated.

[0028] Referring to Figures 2, 3, and 4, the optical operation of the first embodiment of the virtual image display device 100A will be described. First, as shown in Figure 2, the display unit 10 emits image light ML, which is incident on the polarization control member PC1. Here, the image light ML is incident on and passes through the central part of the sealing member including the polarization control member PC1, where the circular polarizer 13 is located, excluding the peripheral part fixed in contact with the first opening (see region AR3 in Figure 3). At this time, as shown in Figure 4, the image light ML emitted from the display unit 10 is converted to right-circularly polarized light C1 after passing through the polarization control member PC1. The right-circularly polarized image light ML C1 incident on the optical member 20 from the display unit 10 is partially transmitted through the reflective optical element 22, but is attenuated to about half its intensity during transmission. The image light ML that has passed through the reflective optical element 22 passes through the lens member 21 and then through the polarization conversion member 224. At this time, the image light ML is refracted by the lens member 21 and relatively focused by positive power. Also, by passing through the polarization conversion member 224 in the forward direction, the image light ML is converted from right-circular polarization C1 to first linear polarization L1 in the first polarization direction and incident on the polarizing optical element 25. The image light ML incident on the polarizing optical element 25 is efficiently reflected by the polarizing optical element 25 while remaining in the first linear polarization L1 state, and when passing through the lens member 21, it is converted to right-circular polarization C1 by passing through the polarization conversion member 224 in the reverse direction. The image light ML emitted from the lens member 21 is reflected by the reflective optical element 22 and relatively focused by positive power, but is attenuated to about half its intensity during reflection. At this time, the image light ML is converted from right-circular polarization C1 to left-circular polarization C2. The left-circularly polarized C2 image light ML reflected by the reflective optical element 22 passes through the polarization conversion member 224 in the forward direction as it passes through the lens member 21, and is converted to second linearly polarized L2 in the second polarization direction before being incident on the polarizing optical element 25. In this way, the image light ML travels back and forth across the lens member 21 due to reflection from the reflective optical element 22, passing through the lens member 21 twice in this back and forth motion, and consequently passing through the lens member 21 a total of three times. The image light ML incident on the polarizing optical element 25 after passing through the lens member 21 is efficiently transmitted through the polarizing optical element 25 while remaining in the second linearly polarized L2 in the second polarization direction.The image light ML emitted outside the optical element 20 is collimated by the focusing action of the optical element 20 and incident on the pupil position PP where the wearer's eye EY is located (see Figure 2). In other words, the wearer US wearing the first virtual image display device 100A can observe a virtual image produced by the image light ML.

[0029] In the case of the display optical systems 103a and 103b shown in Figure 2, since the second optical surface 21b is concave, the ray angle of the image light ML emitted from the image display panel 11 can be tilted inward, i.e., towards the optical axis AX. This allows for a margin in the total reflection angle for the material of the lens member 21, thus increasing the lens curvature and enabling miniaturization of the image display panel 11 and the entire optical system. Furthermore, the following relationship holds regarding the ratio of the curvature R1 of the first optical surface 21a to the curvature R2 of the second optical surface 21b. 0.5 ≤ R1 / R2 ≤ 1.5 By satisfying this condition, the ray angle of the image light ML emitted from the image display panel 11 can be made approximately parallel to the panel normal direction (the direction parallel to the optical axis AX). As a result, for the image viewed by the user through the display optical systems 103a and 103b, the image light ML emitted in the direction of the panel normal is incident on the eye EY, so the virtual image, which is the displayed image, can be viewed without brightness or color unevenness. In particular, the curvature R2 of the second optical surface 21b is preferably between 5 mm and 30 mm.

[0030] Note that the first and second polarization directions are for convenience only, and the specific definitions of the directions can be changed. In other words, in the example shown in Figure 4, the polarizing optical element 25 reflects the first linear polarization L1 in the first polarization direction which is the Y direction, but the polarizing optical element 25 may also reflect the first linear polarization L1 in the first polarization direction which is the X direction. In this case, the direction of the principal axis of the polarization conversion member 224 is adjusted to match the polarizing optical element 25.

[0031] Referring to Figures 2, 3, and 5, the configuration for sealing the first aperture 31 of the lens barrel 30, into which the image light ML from the image display panel 11 enters, will be described. As shown in Figure 2, the lens member 21 seals the second aperture 32 of the lens barrel 30, which emits the image light ML. The polarization control member PC1 is also used as a sealing member to seal the first aperture 31 of the lens barrel 30, which houses the lens member 21, into which the image light ML enters. The sealing member may also include a circular polarizer 13 and a support plate SP.

[0032] As shown in region AR3 of Figure 3, the end of the support plate SP included in the polarization control member PC1, which serves as a sealing member, is held by a first retaining portion 33 provided on the inner side surface of the first opening 31 of the lens barrel 30. The end of the support plate SP functions as a peripheral portion of the sealing member that is fixed to the first opening 31. The first retaining portion 33 and the end of the support plate SP may be bonded together by a first adhesive 42. Here, the gap between the first retaining portion 33 and the end of the support plate SP is sealed by the first adhesive 42 and tape 41, which serve as a dustproof member 40, thereby increasing the airtightness of the first opening 31 of the lens barrel 30 and ensuring dust protection. The tape 41 may be positioned to encircle the gap between the polarization control member PC1 and the first opening 31 to ensure dust protection and to temporarily fix the polarization control member PC1 to the first opening 31.

[0033] Before fixing the position of the polarization control member PC1, which acts as a sealing member, relative to the lens barrel 30 by bonding with the first adhesive 42, the position of the polarization control member PC1 relative to the lens barrel 30 is adjusted. This position adjustment is mainly performed by rotating the polarization control member PC1 in the XY plane perpendicular to the optical axis AX. As shown in region BR1 of Figure 5, the range of position adjustment may be minimized by providing a mechanism that limits the angle by which the polarization control member PC1, which acts as a sealing member, rotates in the XY plane. Region BR1 shows part of the lens barrel 30 and the polarization control member PC1. This mechanism may include a notch 311 provided on the inner side surface of the first opening 31 of the lens barrel 30 and a cutout SP1 provided on the outer side surface of the support plate SP of the polarization control member PC1. As an example, the range of the angle by which the polarization control member PC1 rotates in the XY plane may be about ±10 degrees.

[0034] To prevent foreign matter from entering the inside of the lens barrel 30 when adjusting the position of the polarization control member PC1 relative to the opening 31, the gap between the polarization control member PC1 and the first holding part 33 is sealed with the first adhesive 42 and tape 41 before starting the position adjustment. Here, the tape 41 has sufficient elasticity so as not to hinder the movement and / or rotation of the polarization control member PC1 relative to the opening 31 during the position adjustment, and the first adhesive 42 can be cured at any time after the position adjustment is completed, for example, by UV curing. More specifically, the first adhesive 42 has sufficient fluidity before curing, and the position and direction of the polarization control member PC1 relative to the lens barrel 30 can be adjusted with the first adhesive 42 applied between the holding part 33 of the first opening 31 and the peripheral edge of the support plate SP before curing. Furthermore, the first adhesive 42 has sufficient hardness after curing, and even if stress remains due to the elasticity of the tape 41, it fixes the position and direction of the polarization control member PC1 relative to the lens barrel 30. The tape 41 has sufficient transmittance to UV light so that the UV light that cures the UV-curable first adhesive 42 reaches the first adhesive 42. For example, the tape 41 may be an elastic acrylic-based substrate-less adhesive tape. However, these tapes 41 and the first adhesive 42 are merely examples and do not limit this embodiment.

[0035] Similarly, with respect to the second opening 32, UV-curing adhesive may be applied to the gap between the end of the lens member 21 and the opening 32. After adjusting the position of the lens member 21 relative to the lens barrel 30, UV light may be irradiated from the second opening 32 or the first opening 31 to cure the adhesive. In this way, the lens member 21 can be fixed to the lens barrel 30 and the second opening 32 can be sealed. If the lens member 21 is inserted into the lens barrel 30 through the first opening 31, the first opening 31 should be sealed afterward.

[0036] By sealing the first opening 31 and the second opening 32 of the lens barrel 30 in this manner, it is possible to prevent foreign matter that may be present inside the lens barrel 30 from leaking out to the outside of the lens barrel 30, and to prevent foreign matter that may be present outside the lens barrel 30 from entering the inside of the lens barrel 30. Examples of such foreign matter include dust derived from parts of the first adhesive 42, parts of the tape 41, and sebum from the skin of workers who have touched the components during assembly.

[0037] Referring to Figures 6 and 7, the position adjustment and fixing of the image display panel 11 relative to the lens barrel 30 using the support frame 50 will be described. As shown in Figure 6, the support frame 50 supports the image display panel 11. The support frame 50 also has a projection 51 that protrudes in the -Z direction from which the image display panel 11 emits image light ML, and is fixed to a second holding part 34 provided on the outer side surface of the lens barrel 30 with a second adhesive 43 via the projection 51 (see Figure 7). The image display panel 11 is connected to an FPC (Flexible Printed Circuits) part 11f that transmits control signals from the circuit member 80 to the image display panel 11, and the support frame 50 is provided with a gap 52 to allow the FPC part 11f to pass through without interference.

[0038] As shown in region CR1 of Figure 7, the projection 51 of the support frame 50 is held by a second retaining portion 34 provided on the outer side surface of the first opening 31 of the lens barrel 30. There may be multiple projections 51 on the support frame 50 and multiple second retaining portions 34 on the lens barrel 30. Each projection 51 is fixed to its respective second retaining portion 34 by the second adhesive 43. Region CR1 of Figure 7 shows a cross-section of the portion of the second retaining portion 34 of the lens barrel 30 and the projection 51 of the support frame 50 that is fixed by the second adhesive 43.

[0039] The second adhesive 43, like the first adhesive 42 shown in region AR3 of Figure 3, can be cured at any time after the position adjustment of the support frame 50 relative to the lens barrel 30, and may be, for example, a UV-curing type. That is, the support frame 50 is fixed to the lens barrel 30 by applying the second adhesive 43 before curing between the second holding portion 34 of the lens barrel 30 and the projection 51 of the support frame 50, adjusting the position of the support frame 50 relative to the lens barrel 30, and then curing the second adhesive 43 at any time. Here, the position adjustment of the support frame 50 relative to the lens barrel 30 may include rotation around the Z axis. For example, the range of rotation around the Z axis in this position adjustment may be about 1 degree. The position adjustment of the support frame 50 relative to the lens barrel 30 may include movement parallel to the X axis, Y axis, and Z axis, respectively.

[0040] By adjusting the position of the support frame 50 relative to the lens barrel 30 in this manner, the position of the image display panel 11 fixed to the support frame 50 relative to the lens barrel 30 is also adjusted.

[0041] (modified version) In the above embodiment, a configuration was described in which the image display panel 11 is an OLED or the like, and the polarization control member PC1 includes a circular polarizer 13. As a modification of this configuration, a configuration in which the polarization control member PC1 has a linear polarizer 14 and a quarter-wave plate 15 will be described, as shown in Figure 8. In this case, the image display panel 11 is not limited to a self-emissive image light generation device, but may be composed of an LCD (Liquid Crystal Display) or other light modulation element, and an image may be formed by illuminating the light modulation element with a light source such as a background.

[0042] The polarization control member PC1 has, in order from the image display panel 11 side, a linear polarizer 14 and a quarter-wave plate 15.

[0043] The linear polarizer 14 is, for example, an absorption-type polarizer, and in this embodiment, it selectively allows only the second linearly polarized light (horizontally polarized light) in the horizontal X direction to pass through. In other words, of the image light ML emitted from the image display panel 11, only the linearly polarized light in the X direction passes through the linear polarizer 14 and is incident on the quarter-wave plate 15. The linear polarizer 14 is in sheet form and is manufactured by stretching a film impregnated with a dichroic dye such as iodine in a certain direction.

[0044] The quarter-wave plate 15 has its principal axis or velocity axis set between the vertical and horizontal directions, that is, between the Y direction and the X direction, and converts the second linearly polarized light (horizontally polarized light) that has passed through the linear polarizer 14 into, for example, right-circularly polarized light C1. As an example, the quarter-wave plate 15 may be a film-like phase difference plate made by rolling a polymer. As a specific manufacturing method, a film-like phase difference plate can be produced by creating a density difference and / or refractive index difference in the rolling direction and / or the opposite direction when rolling the polymer. As another example, the quarter-wave plate 15 is formed from a liquid crystal material such as a photocrosslinkable polymer liquid crystal material, but it may also be made by processing a birefringent crystalline material such as quartz into a thin plate. As a specific manufacturing method, the linear polarizer 14 is placed on the cover glass 11c of the image display panel 11, and the quarter-wave plate 15 made of a UV-curable photocrosslinkable polymer liquid crystal material is placed on top of it. The photocrosslinkable polymer liquid crystal material is coated onto a cover glass 11c using methods such as spin coating or inkjet printing to control the film thickness, then irradiated with polarized ultraviolet light, and subsequently baked to function as a quarter-wave plate 15.

[0045] The first embodiment of the virtual image display device 100A, 100B and optical unit 100 described above comprises a lens barrel 30 having a first aperture 31 into which image light ML is incident, a lens member 21 as a first lens fixed inside the lens barrel 30, a polarization control member PC1 and a support plate SP as sealing members fixed to the first aperture 31 and sealing the first aperture 31, and an image display panel 11 fixed outside the lens barrel 30 that generates image light ML that is emitted toward the first lens via the sealing member, wherein the sealing member includes a polarization control member PC1 that converts the image light ML into a predetermined polarization.

[0046] In the above-described virtual image display devices 100A, 100B and optical unit 100, the lens member 21 is built into the lens barrel 30, and the first opening 31 and second opening 32 of the lens barrel 30 are sealed with the polarization control member PC1 and the lens member 21, respectively. As a result, it is possible to prevent foreign matter from entering the lens barrel 30 from the outside to the inside and from leaking foreign matter from the inside to the outside of the lens barrel 30, and to suppress the deterioration of image quality caused by foreign matter being reflected in the image of the image light ML emitted by the image display panel 11 provided on the outside of the lens barrel 30. Furthermore, in the above-described virtual image display devices 100A, 100B and optical unit 100, compared to a configuration in which the circular polarizer 13 or quarter-wave plate 15 of the polarization control member PC1 is attached to the surface of the image display panel 11 or cover glass 11c of the display unit 10 instead of the first opening 31 of the lens barrel 30, the amount by which the image display panel 11 is rotated relative to the lens barrel 30 for purposes such as adjusting the optical axis of the optical system or defocusing can be minimized. Therefore, the above-mentioned virtual image display devices 100A, 100B and optical unit 100 also have the excellent effect of enabling miniaturization of the lens barrel 30 and support frame 50.

[0047] [Second Embodiment] In the first embodiment described above, virtual image display devices 100A, 100B and optical unit 100 were described in which the lens member 21 is composed of a single convex-concave lens. In the second embodiment, virtual image display devices 100A, 100B and optical unit 100 will be described in which the lens member 21 is composed of a plano-convex lens and a plano-concave lens. For the virtual image display devices 100A, 100B and optical unit 100 according to the second embodiment, a detailed explanation of the components other than the lens member 21 that are common to the first embodiment will be omitted.

[0048] As shown in Figure 9, the lens member 21 according to the second embodiment includes a first lens 21A and a second lens 21B. The first lens 21A is a plano-convex lens having a convex third optical surface 21c and a planar fourth optical surface 21d. The first lens 21A is a plano-concave lens having a planar fifth optical surface 21e and a concave sixth optical surface 21f. The second lens 21B and the first lens 21A are arranged in this order inside the lens barrel 30 in the -Z direction from the image display panel 11. The fifth optical surface 21e of the second lens 21B faces the polarization control member PC1, which is a sealing member fixed to the first opening 31 of the lens barrel 30, and the fourth optical surface 21d of the first lens 21A faces the second opening 32 of the lens barrel 30. The sixth optical surface 21f of the second lens 21B and the third optical surface 21c of the first lens 21A face each other. The sixth optical surface 21f of the second lens 21B and the third optical surface 21c of the first lens 21A have complementary shapes and are spherical or aspherical surfaces with rotational symmetry around the optical axis AX.

[0049] Figure 10 includes regions DR1, DR2, DR3, and DR4. Regions DR1, DR2, DR3, and DR4 in Figure 10 are enlarged versions of the structures shown in Figure 9. As shown in region DR2 of Figure 10, the cover glass 11c and the polarization control member PC1 are spaced apart. Also, the support plate SP and the fifth optical surface 21e of the second lens 21B are spaced apart. As shown in region DR4 of Figure 10, the end of the support plate SP included in the polarization control member PC1 as a sealing member is held by a first retaining portion 33 provided on the inner side surface of the first opening 31 of the lens barrel 30. The first retaining portion 33 and the end of the support plate SP may be bonded together by a first adhesive 42. Here, the gap between the first retaining portion 33 and the end of the support plate SP is sealed by the first adhesive 42 and tape 41 as a dustproof member 40, thereby improving the airtightness of the first opening 31 of the lens barrel 30. The tape 41 may be arranged so as to encircle the gap between the polarization control member PC1 and the first opening 31. As shown in region DR3 of Figure 10, a polarization control member PC2 is formed on the surface of the third optical surface 21c of the first lens 21A. The polarization control member PC2 has a reflective optical element 22, which is a transmissive mirror HM. The sixth optical surface 21f of the second lens 21B and the third optical surface 21c of the first lens 21A are bonded together by an adhesive film AD. However, the polarization control member PC2 is formed between the sixth optical surface 21f of the second lens 21B and the adhesive film AD. As shown in region DR1 of Figure 10, a polarization control member PC3 is provided on the surface of the fourth optical surface 21d of the first lens 21A. The polarization control member PC3 has a polarization conversion member 224 and a reflective polarizing optical element 25, in the order from the first lens 21A toward the -Z direction.

[0050] Referring to Figure 11, the optical operation of the virtual image display device 100A of the second embodiment will be described. As shown in Figure 11, the image light ML emitted from the display 10 passes through the polarization control member PC1 and is converted to right-circularly polarized light C1. When the image light ML that has passed through the polarization control member PC1 passes through the second lens 21B, it is refracted by the second lens 21B, which is a plano-concave lens, and is subjected to the effect of relative divergence due to negative power. The right-circularly polarized image light ML that has passed through the second lens 21B and entered the optical element 20 is partially transmitted through the reflective optical element 22, but is attenuated to about half its intensity during transmission. The image light ML that has passed through the reflective optical element 22 passes through the first lens 21A and then through the polarization conversion member 224. By passing through the polarization conversion member 224 in the forward direction, the image light ML is converted from right-circularly polarized light C1 to first linearly polarized light L1 in the first polarization direction and is entered into the polarizing optical element 25. The image light ML incident on the polarizing optical element 25 is efficiently reflected by the polarizing optical element 25 while remaining in its first linear polarization L1 state, and as it passes through the first lens 21A, it is converted to right circular polarization C1 by passing through the polarization conversion member 224 from the opposite direction. The image light ML emitted from the first lens 21A is reflected by the reflective optical element 22 and is relatively focused by positive power, but is attenuated to about half its intensity during reflection. At this time, the image light ML is converted from right circular polarization C1 to left circular polarization C2. The left circular polarization C2 image light ML reflected by the reflective optical element 22 passes through the polarization conversion member 224 from the forward direction as it passes through the first lens 21A, and is converted to second linear polarization L2 in the second polarization direction, and is incident on the polarizing optical element 25. In the above, the image light ML travels back and forth through the first lens 21A due to reflection by the reflective optical element 22, passing through the first lens 21A twice in this back and forth motion, and as a result passes through the first lens 21A three times. The image light ML, which passes through the first lens 21A and enters the polarizing optical element 25, is efficiently transmitted through the polarizing optical element 25 while maintaining its second linear polarization L2 in the second polarization direction. The image light ML emitted outside the optical member 20 is collimated by the focusing action of the optical member 20 and enters the pupil position PP where the wearer's eye EY is located (see Figure 9). In other words, the wearer US wearing the first virtual image display device 100A can observe a virtual image produced by the image light ML.

[0051] (modified version) As shown in Figure 12, in this embodiment as in the first embodiment, the polarization control member PC1 may have a linear polarizer 14 and a quarter-wave plate 15. In this case, the image display panel 11 may be composed of an LCD or other optical modulation element, and an image may be formed by illuminating the optical modulation element with a light source such as a background.

[0052] In the virtual image display devices 100A, 100B and optical unit 100 of the second embodiment described above, the first lens 21A includes a plano-convex lens having a convex surface as a third optical surface 21c and a flat surface as a fourth optical surface 21d, and the virtual image display devices 100A, 100B and optical unit 100 further include a second lens 21B as a plano-concave lens having a concave surface as a sixth optical surface 21f facing the first surface and a flat surface as a fifth optical surface 21e facing the first aperture 31.

[0053] In the virtual image display devices 100A, 100B and optical unit 100 according to the first embodiment described above, the polarization control member PC1 faces the convex surface of the lens member 21, which has a relatively strong curvature. As a result, a lens effect occurs from the polarizer plate included in the polarization control member PC1, which may degrade the resolution performance of the optical system. On the other hand, in the virtual image display devices 100A, 100B and optical unit 100 described above, the polarization control member PC1 faces the plane of the second lens 21B, which is a plano-convex lens. Therefore, compared to the first embodiment, the lens effect of the polarizer plate is reduced, and the degradation of the optical system's resolution performance due to this lens effect can be suppressed.

[0054] A virtual image display device according to a specific embodiment includes a lens barrel having a first aperture into which image light is incident, a first lens fixed inside the lens barrel, a sealing member fixed to the first aperture and sealing the first aperture, and an image display panel fixed outside the lens barrel and generating image light that is emitted toward the first lens via the sealing member, wherein the sealing member includes a polarization control member that converts the image light into a predetermined polarization.

[0055] In a specific embodiment of a virtual image display device, the sealing member comprises a peripheral portion fixed to the first opening and a central portion through which image light passes, where a polarization control member is arranged.

[0056] In a specific embodiment of a virtual image display device, the sealing member further includes a support plate that supports a polarization control member, and the first opening is provided with a first retaining portion that holds the end of the support plate.

[0057] A specific embodiment of the virtual image display device further includes a dustproof member that secures the sealing member to the lens barrel while ensuring dust protection at the first opening of the lens barrel.

[0058] The above-described virtual image display device incorporates a lens element into the lens barrel and seals the first opening of the lens barrel with a polarization control element. As a result, it is possible to prevent foreign matter from entering the lens barrel from the outside to the inside and from leaking out of the lens barrel to the outside, thereby suppressing the deterioration of image quality caused by foreign matter being reflected in the image of the light emitted by the image display panel located outside the lens barrel.

[0059] In a specific embodiment of a virtual image display device, the dustproof member includes an elastic tape that temporarily fastens the sealing member to the first opening of the lens barrel while ensuring dustproofing, and a first adhesive that has fluidity before curing that allows adjustment of the position and direction of the polarization control member relative to the lens barrel, and fixes the position and direction of the polarization control member relative to the lens barrel after curing.

[0060] A virtual image display device according to a specific embodiment further comprises a support frame for supporting an image display panel, the lens barrel further comprises a second holding portion for holding the support frame, and further comprises a second adhesive that can be cured at any time and fixes the support frame to the second holding portion of the lens barrel while the position and orientation of the image display panel relative to the lens barrel are adjusted.

[0061] The above-mentioned virtual image display device uses an elastic tape and an adhesive that can be cured at any time as dustproof members, allowing the polarization control member and the image display panel to be fixed to the lens barrel 30 after their positions have been adjusted relative to the lens barrel 30.

[0062] In a specific embodiment of a virtual image display device, the lens barrel further has a second aperture that emits image light that has passed through a first lens, and the first lens seals the second aperture.

[0063] The above-described virtual image display device seals the second opening of the lens barrel with a first lens. As a result, it is possible to prevent foreign matter from entering the lens barrel from the outside to the inside and from leaking out of the lens barrel, thereby suppressing the deterioration of image quality caused by foreign matter being reflected in the image light emitted by the image display panel located on the outside of the lens barrel.

[0064] In a specific embodiment of a virtual image display device, the polarization control member converts image light from an image display panel into circularly polarized light, a half-mirror is provided on the first optical surface facing the first aperture of the first lens, a polarization conversion member is provided on the second optical surface facing the second aperture of the first lens that converts linearly polarized light into circularly polarized light and circularly polarized light into linearly polarized light, and a polarizing optical element is provided on the outside of the polarization conversion member on the second optical surface that reflects the first linearly polarized light and transmits the second linearly polarized light.

[0065] In a specific embodiment of a virtual image display device, the first lens includes a pancake lens having a convex surface as a first optical surface and a concave surface as a second optical surface.

[0066] The above-mentioned virtual image display device achieves miniaturization and weight reduction by changing the polarization of the image light between the optical surfaces of a pancake lens, reflecting it, and then delivering it to the wearer's eyes.

[0067] In a specific embodiment of a virtual image display device, the first lens includes a plano-convex lens having a convex surface as a first optical surface and a flat surface as a second optical surface, and further comprises a second lens as a plano-concave lens having a concave surface as a third optical surface facing the first optical surface and a flat surface as a fourth optical surface facing the first aperture.

[0068] The above-mentioned virtual image display device uses a second lens whose optical surface facing the polarization control member is planar, thereby suppressing the deterioration of the optical system's resolution performance due to the lens effect between the polarization control member and the lens facing the polarization control member.

[0069] In a specific embodiment of a virtual image display device, the image display panel comprises an OLED panel that generates image light, and the polarization control member includes a circular polarizing element that converts the image light from the image display panel into circularly polarized light.

[0070] In a specific embodiment of a virtual image display device, the image display panel comprises a liquid crystal panel that generates image light, and the polarization control member includes a polarizer that extracts a predetermined linearly polarized component from the image light from the image display panel, and a quarter-wave plate that converts linearly polarized light into circularly polarized light.

[0071] The above-mentioned virtual image display device can employ OLED panels and liquid crystal panels as image display panels.

[0072] An optical unit according to a specific embodiment includes a lens barrel having a first aperture into which image light is incident, a first lens fixed inside the lens barrel, a sealing member fixed to the first aperture and sealing the first aperture, and an image display panel fixed outside the lens barrel and generating image light that is emitted toward the first lens via the sealing member, wherein the sealing member includes a polarization control member that converts the image light into a predetermined polarization.

[0073] The optical unit described above incorporates a lens element within the lens barrel and seals the first opening of the lens barrel with a polarization control element. As a result, it prevents foreign matter from entering the lens barrel from the outside and from leaking out of the lens barrel, thereby suppressing the degradation of image quality caused by foreign matter being reflected in the image emitted by the image display panel located outside the lens barrel.

[0074] The invention made by the inventor has been described in detail based on embodiments above, but it goes without saying that the present invention is not limited to these embodiments and can be modified in various ways without departing from its essence. Furthermore, the features described in the embodiments can be freely combined within a range that does not contradict the technical aspects. [Explanation of Symbols]

[0075] 10...Display unit, 11...Image display panel, 11c...Cover glass, 11d...Display surface, 13...Circular polarizer, 20...Optical component, 21...Lens component, 21A,21B...Lens, 21a,21b,21c,21d,21e,21f Optical surface, 22...Reflective optical element, 25...Polarizing optical element, 30...Lens barrel, 31,32...Aperture, 33,34...Holding part, 40...Dustproof component, 41...Tape, 42,43...Adhesive, 50...Support frame, 51...Protrusion, 80...Circuit component, 90...User terminal, 100...Optical unit, 100A,100B...Virtual image display device, 100C...Temple, 102...Drive device, 102a,102b...Display drive unit, 103a,103b...Display optical system, 200…Head-mounted display device (HMD), 224…Polarization conversion member, 311…Notch, AD…Adhesive film, AR1, AR2, AR3…Region, AX…Optical axis, BR1…Region, C1, C2…Circular polarization, CR1…Region, DR1, DR2, DR3, DR4…Region, EY…Eye, HM…Mirror, L1, L2…Linear polarization, ML…Image light, PC1, PC2, PC3…Polarization control member, PP…Pupil position, SP…Support plate, SP1…Notch, US…Wearer

Claims

1. A microscope tube having a first aperture into which image light enters, A first lens fixed inside the lens barrel, A sealing member fixed to the first opening and sealing the first opening, An image display panel fixed to the outside of the lens barrel and generating the image light that is emitted toward the first lens via the sealing member, Equipped with, The sealing member is Polarization control member that converts the aforementioned image light to a predetermined polarization including, Virtual image display device.

2. The sealing member is The peripheral portion fixed to the first opening, The polarization control member is arranged in the central part through which the image light passes, Equipped with, The virtual image display device according to claim 1.

3. The sealing member is Support plate for supporting the polarization control member It further includes, The first opening is, First retaining part that holds the end of the support plate Equipped with, The virtual image display device according to claim 1.

4. A dustproof member that secures the sealing member and the lens barrel while ensuring dust protection at the first opening of the lens barrel. Furthermore, The virtual image display device according to claim 3.

5. The dustproof member is A tape that is elastic and temporarily fastens the sealing member to the first opening of the lens barrel while ensuring dust protection, A first adhesive that, before curing, has fluidity that allows adjustment of the position and direction of the polarization control member relative to the lens barrel, and after curing, fixes the position and direction of the polarization control member relative to the lens barrel, including, The virtual image display device according to claim 4.

6. Support frame for supporting the image display panel Furthermore, The aforementioned lens barrel is Second retaining part that holds the support frame Furthermore, A second adhesive that can be cured at any time and fixes the support frame to the second holding portion of the lens barrel while the position and orientation of the image display panel relative to the lens barrel are adjusted. Furthermore, The virtual image display device according to claim 1.

7. The aforementioned lens barrel is The second aperture emits the image light that has passed through the first lens. It further possesses, The first lens seals the second aperture. The virtual image display device according to claim 1.

8. The polarization control member converts the image light from the image display panel into circularly polarized light. A half-mirror is provided on the first optical surface of the first lens facing the first aperture. A polarization conversion member is provided on the second optical surface of the first lens facing the second aperture, which converts linearly polarized light into circularly polarized light and circularly polarized light into linearly polarized light. On the second optical surface, outside the polarization conversion member, a polarizing optical element is provided that reflects the first linearly polarized light and transmits the second linearly polarized light. The virtual image display device according to claim 7.

9. The first lens includes a pancake lens having a convex surface as a first optical surface and a concave surface as a second optical surface. The virtual image display device according to claim 8.

10. The first lens includes a plano-convex lens having a convex surface as a first optical surface and a flat surface as a second optical surface. The invention further comprises a second lens as a plano-concave lens having a concave surface as a third optical surface facing the first optical surface and a flat surface as a fourth optical surface facing the first aperture. The virtual image display device according to claim 8.

11. The aforementioned image display panel is The OLED (Organic Light Emitting Diode) panel that generates the aforementioned image light. Equipped with, The polarization control member is A circular polarizing element that converts the image light from the image display panel into circularly polarized light. including, The virtual image display device according to claim 1.

12. The aforementioned image display panel is The liquid crystal panel that generates the aforementioned video light Equipped with, The polarization control member is A polarizing plate for extracting a predetermined linearly polarized component from the image light from the image display panel, A quarter-wave plate that converts linearly polarized light into circularly polarized light, including, The virtual image display device according to claim 1.

13. A microscope tube having a first aperture into which image light enters, A first lens fixed inside the lens barrel, A sealing member fixed to the first opening and sealing the first opening, An image display panel fixed to the outside of the lens barrel and generating the image light that is emitted toward the first lens via the sealing member, Equipped with, The sealing member is Polarization control member that converts the aforementioned image light to a predetermined polarization including, Optical unit.

Images