Virtual image display

Abstract

To provide a virtual image display to which an environmental material is applied.SOLUTION: A virtual image display 100 includes: an image formation unit 11; a projection light optical system 2 in which an image light ML formed by the image formation unit 11 enters; and a reflection member 23 for reflecting the image light ML emitted from the projection optical system 2 and projecting a virtual image. At least parts of the projection optical system 2 and the reflection member 23 are an environmental member EM formed of an environmental material.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a virtual image display device using environmentally friendly materials. [Background technology]

[0002] A virtual image display device is disclosed that includes an image element that emits image light, a light guiding member that guides the image light, and a projection optical system that makes the image light from the image element incident on the light guiding member (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-111363 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a virtual image display device such as that of Patent Document 1, in order to reduce carbon dioxide generated during thermal recycling, it is preferable to configure the optical members with environmentally friendly materials. However, optical materials have problems with heat resistance and disposal of optical films, etc. during recycling, making it difficult to replace them with environmentally friendly materials. In addition, since the characteristics required for the optical members constituting the virtual image display device are different from the characteristics of environmentally friendly materials, it is difficult to simply replace the resin material with the environmentally friendly material.

[0005] Furthermore, in the field of use of virtual image display devices, it is conceivable that a large number of virtual image display devices will be operated in the fields of tourism and amusement, and in order to ensure image quality, it is desirable for the operator of the device to be able to easily check whether the brightness of the image has reached the end of its product life. [Means for solving the problem]

[0006] A virtual image display device according to one aspect of the present invention comprises an image forming unit, a projection optical system into which image light formed by the image forming unit is incident, and a reflective member that reflects the image light emitted from the projection optical system to project a virtual image, and at least a portion of the projection optical system and the reflective member are environmental members formed from environmental materials.

[0007] A virtual image display device according to one aspect of the present invention comprises an image forming unit, a projection optical system into which image light formed by the image forming unit is incident, a reflecting member that reflects the image light emitted from the projection optical system to project a virtual image, and a dimming member that is arranged on an optical path between the image forming unit and the virtual image, has optical transparency and is capable of dimming the image light, and is formed from an environmentally friendly material. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is an external perspective view illustrating a wearing state of the virtual image display device according to the first embodiment. [Diagram 2] FIG. 2 is a side cross-sectional view illustrating the internal structure of the virtual image display device. [Diagram 3] 4 is a partial enlarged view illustrating a reflecting member in the optical system of the virtual image display device. FIG. [Figure 4] FIG. 2 is a block diagram illustrating a circuit configuration of the virtual image display device. [Diagram 5] 2 is a conceptual diagram mainly illustrating a life management unit of the virtual image display device. FIG. [Figure 6] 11 is a conceptual diagram illustrating a state in which a light-reducing member has been altered and turned cloudy. FIG. [Figure 7] FIG. 11 is a cross-sectional view illustrating an internal structure of a virtual image display device according to a second embodiment. [Figure 8] 8 is a partial enlarged view for explaining a reflecting member in the optical system of the virtual image display device of FIG. 7. [Figure 9] FIG. 11 is a side cross-sectional view illustrating a virtual image display device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [First embodiment] Hereinafter, a virtual image display device according to a first embodiment of the present invention will be described with reference to FIGS.

[0010] FIG. 1 is a diagram for explaining a wearing state of a head mounted display (hereinafter also referred to as HMD) 200. The HMD 200 allows an observer or wearer US wearing it to recognize an image as a virtual image. In FIG. 1 and the like, X, Y, and Z are an orthogonal coordinate system, and the +X direction corresponds to the lateral direction in which both eyes EY of the observer or wearer US wearing the HMD 200 or the virtual image display device 100 are aligned, the +Y direction corresponds to the upward direction perpendicular to the lateral direction in which both eyes EY are aligned for the wearer US, and the +Z direction corresponds to the forward direction or front direction for the wearer US. The ±Y directions are parallel to the vertical axis or vertical direction.

[0011] The HMD 200 includes a first display device 100A for the right eye, a second display device 100B for the left eye, a pair of temple-shaped support devices 100C for supporting the display devices 100A and 100B, and a user terminal 90 which is an information terminal. The first display device 100A is composed of a display drive unit 102 arranged at the top and an exterior member 103 in the shape of a glasses lens and covering the front of the eyes. Similarly, the second display device 100B is composed of a display drive unit 102 arranged at the top and an exterior member 103 in the shape of a glasses lens and covering the front of the eyes. The support device 100C is a mounting member that is mounted on the head of the wearer US and supports the upper end side of the exterior member 103 via the display drive unit 102. The first display device 100A and the second display device 100B are optically reversed, and a detailed description of the second display device 100B will be omitted.

[0012] FIG. 2 is a side cross-sectional view for explaining the optical structure of the first display device 100A. The first display device 100A includes a display element 11, an imaging optical system 20, a life management unit 61, and a display control device 88. The display element 11 and the display control device 88 correspond to the image forming unit. Note that only the display element 11 may be referred to as the image forming unit. The imaging optical system 20 includes a projection lens 21, a prism mirror 22, and a see-through mirror 23. In the imaging optical system 20, the projection lens 21 and the prism mirror 22 correspond to the projection optical system 2 into which the video light or image light ML corresponding to the video or image is incident, and the see-through mirror 23 corresponds to a reflecting member that reflects the image light ML emitted from the projection optical system 2 toward the eye EY or the pupil position PP. The projection lens 21 and the prism mirror 22, which are the projection optical system 2, form an intermediate image by enlarging and projecting it, and the see-through mirror 23, which is a reflecting member, further enlarges the intermediate image formed on the light exit side of the prism mirror 22. In addition, in the imaging optical system 20, the projection lens 21 and the prism mirror 22 correspond to the display drive unit 102 shown in Fig. 1, and the see-through mirror 23 corresponds to the exterior member 103 shown in Fig. 1. The combination of the display element 11, the projection lens 21, and the prism mirror 22 is called the projection optical system 12, which are fixed inside the case 51 while being aligned with each other.

[0013] The case 51 is a housing or a support member, and is made of a light-shielding material. In addition to the projection optical system 12, the case 51 supports a display control device 88 that operates the display element 11. The case 51 has an opening 51a, an upper cover 51b, and a lower cover 51c. The upper cover 51b covers the entire projection optical system 12 and the display control device 88. The lower cover 51c is joined to the lower end of the upper cover 51b. The opening 51a is provided in the lower cover 51c, and enables the projection optical system 12 to emit image light ML to the outside. In the lower cover 51c, the opening 51a is provided with a transmission window 53 for dustproofing and waterproofing.

[0014] Inside the case 51, above the lower cover 51c and the transparent window 53, a dimming member 62 of the lifespan management unit 61, which will be described later, is provided. Although details will be described later, the dimming member 62 can dim the image light by being altered so that the wearer US cannot easily see the virtual image after the display element 11 has elapsed its lifespan, in order to notify the wearer US of the lifespan of the display element 11. The dimming member 62 has optical transparency, and does not reduce the amount of the image light ML until the lifespan is reached.

[0015] Outside the case 51, a sensor 66 of the life management unit 61, which will be described later, is provided on the wearer US side. The sensor 66 is attached to the case 51, which is a support member. In the example of Fig. 1, the sensor 66 is disposed between the first display device 100A and the second display device 100B, at a position facing the space between the eyebrows of the wearer US when the virtual image display device 100 is worn by the wearer US. As will be described in detail later, the sensor 66 detects that the wearer US is wearing the device.

[0016] 2, the display element 11 is a self-luminous display device. The display element 11 is, for example, an organic EL (organic electro-luminescence) display, and forms a color still image or a moving image on a two-dimensional display surface 11a. The display element 11 is driven by a display control device 88, which is a control unit, to perform a display operation.

[0017] The display element 11 is not limited to an organic EL display, and may be replaced with a display device using an inorganic EL, an organic LED, an LED array, a laser array, a quantum dot light-emitting element, or the like. The display element 11 is not limited to a self-luminous image light generating device, and may be composed of an LCD (Liquid crystal display) or other light modulation element, and may form an image by illuminating the light modulation element with a light source such as a backlight. As the display element 11, instead of an LCD, LCOS (Liquid crystal on silicon, LCoS is a registered trademark), a digital micromirror device, or the like may be used.

[0018] The imaging optical system 20 is an off-axis optical system OS due to the fact that the see-through mirror 23 is a concave mirror. In this embodiment, the projection lens 21, the prism mirror 22, and the see-through mirror 23 are arranged non-axisymmetrically and have a non-axisymmetric optical surface. In this imaging optical system 20, the optical axis AX is bent in an off-axis plane parallel to the YZ plane, and the optical elements 21, 22, and 23 are arranged along the off-axis plane. In the off-axis plane parallel to the YZ plane, the optical path P1 from the projection lens 21 to the internal reflection surface 22b, the optical path P2 from the internal reflection surface 22b to the see-through mirror 23, and the optical path P3 from the see-through mirror 23 to the pupil position PP are arranged to be folded back in two stages in a Z-shape. In this case, the optical elements 21, 22, and 23 constituting the first display device 100A are arranged at different height positions in the vertical direction, which prevents the width of the first display device 100A from increasing.

[0019] In the imaging optical system 20, the projection lens 21 includes a first lens 21o, a second lens 21p, and a third lens 21q. The projection lens 21 receives the image light ML emitted from the display element 11 and makes it incident on the prism mirror 22. The projection lens 21 condenses the image light ML emitted from the display element 11 into a state close to a parallel light beam. The prism mirror 22 has an entrance surface 22a corresponding to the entrance portion, an inner reflection surface 22b corresponding to the reflection portion, and an exit surface 22c corresponding to the exit portion. The prism mirror 22 outputs the image light ML incident from the front so as to be folded back in a direction inclined with respect to a direction in which the incident direction is reversed (the direction of the light source as seen from the prism mirror 22). The see-through mirror 23 has a reflection surface 23a and an outer surface 23o. The see-through mirror 23 enlarges an intermediate image formed on the light exit side of the prism mirror 22.

[0020] The optical surfaces, i.e., the entrance surface and the exit surface, of the first lens 21o, the second lens 21p, and the third lens 21q constituting the projection lens 21 are asymmetrical with respect to the optical axis AX in the vertical direction parallel to the YZ plane and intersecting the optical axis AX, and are symmetrical with respect to the optical axis AX in the horizontal direction or X direction. The optical surfaces of the first lens 21o, the second lens 21p, and the third lens 21q are, for example, free-form surfaces. The optical surfaces are not limited to free-form surfaces, and may be aspherical surfaces. By making the optical surfaces free-form surfaces or aspherical surfaces, aberrations can be reduced. The first lens 21o, the second lens 21p, and the third lens 21q are formed of, for example, optical resin, but may also be made of glass. An anti-reflection film may be formed on the optical surfaces of the first lens 21o, the second lens 21p, and the third lens 21q.

[0021] The prism mirror 22 is an optical member having a refractive and reflective function, which has a function of combining a mirror and a lens, and reflects the image light ML from the projection lens 21 while refracting it. Specifically, the prism mirror 22 allows the image light ML to enter the inside through the entrance surface 22a, totally reflects the entered image light ML in a non-front direction by the internal reflection surface 22b, and emits the entered image light ML to the outside through the exit surface 22c. The entrance surface 22a, the internal reflection surface 22b, and the exit surface 22c, which are optical surfaces constituting the prism mirror 22, are asymmetric about the optical axis AX in the vertical direction parallel to the YZ plane and intersecting the optical axis AX, and are symmetric about the optical axis AX in the horizontal direction or X direction. The prism mirror 22 is formed of, for example, an optical resin, but can also be made of glass. The optical surfaces of the prism mirror 22, that is, the entrance surface 22a, the internal reflection surface 22b, and the exit surface 22c, are, for example, free-form surfaces. The entrance surface 22a, the inner reflection surface 22b, and the exit surface 22c are not limited to free-form surfaces, but may be aspheric surfaces. In the prism mirror 22, by making the optical surfaces 22a, 22b, and 22c free-form or aspheric, aberration can be reduced, and in particular, when a free-form surface is used, it is easy to improve the optical performance of the decentering system. The inner reflection surface 22b is not limited to a surface that reflects the image light ML by total reflection, but may be a reflection surface made of a metal film or a dielectric multilayer film. In this case, a reflection film made of a single layer or multilayer film made of a metal such as Al or Ag is formed on the inner reflection surface 22b by deposition or the like, or a sheet-like reflection film made of a metal is attached. Although detailed illustration is omitted, an anti-reflection film is formed on the entrance surface 22a and the exit surface 22c.

[0022] The see-through mirror 23 is a curved plate-like reflective optical member that functions as a concave surface mirror and reflects the image light ML from the prism mirror 22. That is, the see-through mirror 23 reflects the image light ML from the prism mirror 22 arranged in the emission area of ​​the projection optical system 12 toward the pupil position PP. The see-through mirror 23 covers the pupil position PP where the eye EY or pupil is arranged, has a concave shape toward the pupil position PP, and has a convex shape toward the outside world. The see-through mirror 23 is a concave transmission mirror that covers the entire effective area of ​​the screen in the field of view. The see-through mirror 23 is a collimator with a converging function, and converges the chief ray of the image light ML emitted from each point on the display surface 11a, which is once spread by imaging near the emission side of the prism mirror 22 of the projection optical system 12, to the pupil position PP. The see-through mirror 23 is a mirror plate having a structure in which a mirror film 23c, which is a half mirror having transparency, is formed on the front or back surface of a plate-like body 23b, which is a base material. The reflecting surface 23a of the see-through mirror 23 is asymmetric about the optical axis AX in the vertical direction that is parallel to the YZ plane and intersects with the optical axis AX, and is symmetric about the optical axis AX in the horizontal or X direction. The reflecting surface 23a of the see-through mirror 23 is, for example, a free-form surface. The reflecting surface 23a is not limited to a free-form surface, and can also be an aspheric surface. By making the see-through mirror 23 a free-form surface or an aspheric surface, it is possible to reduce aberrations, and in particular, when a free-form surface is used, it becomes easier to reduce aberrations in the imaging optical system 20, which is an off-axis optical system OS or a non-coaxial optical system.

[0023] The see-through mirror 23 is a transmissive reflecting element that transmits a portion of light when reflected, and the reflecting surface 23a or the mirror film 23c of the see-through mirror 23 is formed of a semi-transparent reflecting layer. As a result, the outside light OL passes through the see-through mirror 23, making it possible to see through the outside world and superimposing a virtual image on the outside world image. In this case, if the plate-shaped body 23b supporting the mirror film 23c is thin, such as a few mm or less, the change in magnification of the outside world image can be kept small. The reflectance of the mirror film 23c to the image light ML and the outside world light OL is set to 10% or more and 50% or less in the expected range of incidence angles of the image light ML, from the viewpoint of ensuring the brightness of the image light ML and facilitating the observation of the outside world image by the see-through.

[0024] In this embodiment, the plate-shaped body 23b, which is the base material of the see-through mirror 23, is an environmentally friendly member EM and is made of an environmentally friendly material. The environmental material is an organic resource containing raw materials derived from plants, for example, biomass plastic. The environmental material may be a biodegradable plastic or a non-biodegradable plastic. Examples of the biodegradable plastic include amorphous polylactic acid (PLA) and polyhydroxybutyric acid (PHB). Examples of the non-biodegradable plastic include biopolyethylene (PE) and biopolyethylene terephthalate (PET). The plate-shaped body 23b has the same thickness as the support plate BP that supports it from the periphery. The support plate BP is made of the same material as the plate-shaped body 23b.

[0025] As shown in an enlarged view in FIG. 3, a mirror film 23c, which is a half mirror, is attached to the plate-like body 23b of the see-through mirror 23 via a peelable film 24. This allows the half mirror portion, which is a functional film, i.e., the mirror film 23c and the film 24 to be easily removed from the see-through mirror 23 when the virtual image display device 100 is discarded, and the plate-like body 23b, which is an environmental member EM, to be easily recycled. The film 24 is a light-transmitting sheet, and is attached to the surface of the plate-like body 23b by, for example, a double-sided adhesive OCA (Optical Clear Adhesive) tape 25. The OCA tape 25 is formed of an elastomer. The film 24 has a mirror film 23c on the surface opposite to the surface attached to the plate-like body 23b. In other words, the film 24 serves as a support material for the mirror film 23c. The mirror film 23c is formed on the film 24 by deposition or the like. For convenience of explanation, the film 24, OCA tape 25, mirror film 23c, etc. shown in FIG. 3 are depicted as being thick, but in reality, they are relatively thin films having a total thickness of several hundred μm or less.

[0026] The mirror film 23c is formed of, for example, a dielectric multilayer film consisting of a plurality of dielectric layers whose thicknesses are adjusted. The mirror film 23c may be a single layer film or a multilayer film of a metal such as Al or Ag whose thicknesses are adjusted. The mirror film 23c can be formed by lamination. The mirror film 23c may include a hard coat layer as a base or a coating.

[0027] Although not shown, a hard coat layer or an anti-reflection film may be formed on the outer surface 23o of the plate-like body 23b. The anti-reflection film may be disposed via a peelable film 24, as with the mirror film 23c, or may be disposed directly on the outer surface 23o if the anti-reflection film has little environmental impact. Also, the anti-reflection film may not be provided on the outer surface 23o.

[0028] Regarding the optical path, the image light ML from the display element 11 enters the projection lens 21 and is emitted from the projection lens 21 in a substantially collimated state. The image light ML that passes through the projection lens 21 enters the prism mirror 22 and passes through the entrance surface 22a while being refracted, is reflected by the inner reflection surface 22b with a high reflectance rate close to 100%, and is refracted again by the exit surface 22c. The image light ML from the prism mirror 22 enters the see-through mirror 23 and is reflected by the reflection surface 23a with a reflectance rate of about 50% or less. The image light ML reflected by the see-through mirror 23 enters the pupil position PP where the eye EY or pupil of the wearer US is located. The outside light OL that passes through the see-through mirror 23 and the support plate BP around it also enters the pupil position PP. In other words, the wearer US wearing the first display device 100A can observe a virtual image by the image light ML superimposed on the outside world image. The dimming member 62 does not dim the image light ML until the life time of the virtual image display device 100 is reached. Although details will be described later, when the life time is reached, the dimming member 62 is altered under the control of the display control device 88, and the image light ML passing through the dimming member 62 is dimmed, making the virtual image difficult to see, so that the wearer US can recognize the reaching of the life time of the virtual image display device 100. In other words, the optical deterioration of the first display device 100A can be clearly recognized visually. Normally, it is difficult to determine the deterioration of the first display device 100A, specifically the display element 11, but by intentionally making the virtual image difficult to see after the life time has elapsed, even a general user can easily determine that the life time has been reached.

[0029] With reference to FIG. 4, the circuit system 80 of the HMD 200, i.e., the virtual image display device 100, will be described. The HMD 200 includes a display control device 88, a pair of display elements 11, and a user terminal circuit 91 as the circuit system 80. One of the display elements 11 is incorporated in the first display device 100A, and the other display element 11 is incorporated in the second display device 100B. The display control device 88 functions as a control unit. In the illustrated example, the display control device 88 is expressed as being incorporated in the first display device 100A, but may be independent of the first display device 100A and the second display device 100B. Note that a combination of the display control device 88 with either the first display device 100A or the second display device 100B is also called a virtual image display device 100, and displays a virtual image for one eye. The first display device 100A will be described below.

[0030] The display control device 88 includes an arithmetic processing device 81a, a storage device 81m, and a data communication interface 81c. The display control device 88 also includes a heat generation control unit 63c, a life counting unit 64, and a life determination unit 65. The heat generation control unit 63c, the life counting unit 64, and the life determination unit 65 constitute a life management unit 61, which will be described later.

[0031] The storage device 81m stores a program that causes the first display device 100A and the second display device 100B to perform display operations. The storage device 81m also stores images acquired from a user terminal 90, which is an information terminal, images generated by the arithmetic processing device 81a, and the like. The storage device 81m also has a frame memory.

[0032] The display control device 88 controls the integrated display time of the display element 11 and causes the display element 11 to perform a display operation.

[0033] The display control device 88 receives display data corresponding to the image data from the user terminal circuit 91 via the data communication interface 81c. The display control device 88 outputs image data, which is the display data stored in the frame memory, to the display element 11 via the data communication interface 81c.

[0034] The user terminal circuit 91 is incorporated in the user terminal 90, and includes a main control device 91a, a storage device 91m, a data communication interface 91c, a mobile wireless communication device 91t, and a user interface device 91i. The user terminal circuit 91 can communicate with various devices such as external servers via a communication network (not shown) using the mobile wireless communication device 91t. The storage device 91m stores a basic program for operating the user terminal circuit 91, and stores a plurality of application software programs including a viewer for playing videos and a web browser as application software programs that operate on the basic program. The user terminal circuit 91 operates in response to a request from the user interface device 91i operated by the user, and outputs videos and still images stored in the storage device 91m in association with the application software to the display control device 88 in a predetermined format, or acquires videos and still images corresponding to various contents via the mobile wireless communication device 91t, and outputs the acquired display data to the display control device 88 in a predetermined format.

[0035] Hereinafter, the life management unit 61 that uses the light reducing member 62 will be described with reference to FIGS.

[0036] As shown in Fig. 5, the life management unit 61 is composed of a dimming member 62, a heating unit 63, a life counting unit 64, a life determination unit 65, and a sensor 66. In Fig. 5, the dimming member 62 and the heating unit 63 of the life management unit 61 are shown diagrammatically when viewed from the vertical direction, specifically, the +Y direction.

[0037] The dimming member 62 changes the transmission state of the image light ML, thereby making it possible to visually notify the life of the display element 11. If the dimming member 62 is subjected to an action of altering the quality of the dimming member 62 to dim the image light ML after the life time of the display element 11, i.e., the life time of the virtual image display device 100, has elapsed, the projected virtual image becomes difficult to see, and even a general user can easily determine that the life time has been reached. Examples of alteration such as dimming the dimming member 62 include, as shown in FIG. 6, making the dimming member 62 cloudy by heating and deforming the dimming member 62 (not shown). When the dimming member 62 is relatively thick, it is preferable to make the dimming member 62 cloudy. When the dimming member 62 is relatively thin, it is preferable to deform the dimming member 62. Note that both the phenomenon of clouding and deformation can occur depending on the thickness of the dimming member 62.

[0038] After the expected life time of the display element 11 has elapsed, the life management unit 61 causes the dimming member 62 to become cloudy by the heating unit 63. In this case, the internal refractive index of the dimming member 62 changes, the transmittance decreases, and the brightness of the image decreases, making it difficult to see the projected virtual image. In addition, after the expected life time of the display element 11 has elapsed, the life management unit 61 causes the heating unit 63 to deform the dimming member 62. In this case, the internal refractive index of the dimming member 62 changes, causing the image to become distorted, making it difficult to see the projected virtual image.

[0039] 2, as described above, the light-reducing member 62 is provided inside the case 51, and is disposed on the optical path between the display element 11, which is the image forming unit, and the pupil position PP. Specifically, the light-reducing member 62 is disposed on the optical path between the projection optical system 12 and the see-through mirror 23 in the case 51. This allows the light-reducing member 62 to be stably disposed.

[0040] The light reducing member 62 is a film-like or sheet-like member, and has a substantially constant thickness. The light reducing member 62 has a thickness of 0.2 mm or less. The light reducing member 62 preferably has a thickness of 0.03 mm or more and 0.2 mm or less.

[0041] The dimming member 62 has a rectangular shape that covers the entire transmission window 53, and one of the four sides of the dimming member 62 is connected at the bottom to a heating element 63a of the heating unit 63, which will be described later. The heating element 63a is fixed to the lower cover 51c. Three of the four sides of the dimming member 62 that are not connected to the heating element 63a are not fixed to any parts, and may be lightly pressed from above to prevent the dimming member 62 from shifting in position. In the illustrated example, the dimming member 62 is lightly pressed by a pressing part 67 at one side facing the heating element 63a. If only one side of the dimming member 62 is fixed, the dimming member 62 is not prevented from deforming. When the dimming of the dimming member 62 is performed by opacification, the dimming member 62 may be completely fixed.

[0042] The dimming member 62 is made of an environmentally friendly material. An example of the environmentally friendly material of the dimming member 62 is a biomass plastic, such as amorphous polylactic acid. Polylactic acid (PLA) can be easily chemically synthesized from plant-derived lactic acid. If the polylactic acid in the dimming member 62 is amorphous, it becomes cloudy due to microcrystallization caused by heat at a predetermined temperature, and the image light ML from the display element 11 is dimmed or blurred, thereby reversibly restricting the use of the virtual image display device 100.

[0043] The heating unit 63 has a heating element 63a connected to the dimming member 62, a heat insulating member 63b, and a heat generation control unit 63c. The heating unit 63 passes an electric current through the heating element 63a under the control of the heat generation control unit 63c to heat the heating element 63a. The heating element 63a is a heater that generates heat when an electric current is supplied thereto, and is made of, for example, a nichrome wire. The heat insulating member 63b is disposed so as to cover the heating element 63a, and prevents the heat of the heating element 63a from reaching the surroundings when it is heated. The heat insulating member 63b can be, for example, foamed plastic. The heat generation control unit 63c is provided in association with the display control device 88, and controls the operation of the heating element 63a.

[0044] The life counting unit 64 accumulates the operating time of the display element 11. The life counting unit 64 is provided, for example, in association with the display control device 88. The life counting unit 64 is an electronic component that counts the accumulated display time of the display element 11 as a circuit configuration. Here, the life time is, for example, the time until the brightness of an image formed by the display element 11 is reduced by half. The life time may be set in advance by the manufacturer, or the brightness of an image displayed on the display element 11 may be detected by a sensor (not shown) or the like.

[0045] The life determination unit 65 determines whether the operation time accumulated by the life count unit 64 has exceeded a predetermined life time (e.g., a time to reduce brightness by half). Specifically, when the operation time of the display element 11 reaches a predetermined time, the life determination unit 65 determines that the expected life time of the display element 11 has been reached. When the life determination unit 65 determines that the life time of the display element 11 has elapsed, it operates the heating unit 63 to heat the dimming member 62, thereby changing the dimming member 62 into a dimming state in which the image light ML is dimmed.

[0046] The sensor 66 detects that the wearer US has worn the device. The display element 11 operates when the sensor 66 detects that the wearer US has worn the device. Specifically, when the sensor 66 detects that the virtual image display device 100 has been worn by the wearer US, it outputs a detection signal to the display control device 88. When the display control device 88 receives the detection signal, it operates the display element 11. In this case, the display time of the image on the display element 11 corresponds to the accumulated time of the life time. This allows the operation of the display element 11 to be linked with the wearing of the wearer US, and the life of the display element 11 to be appropriately managed. Examples of the sensor 66 include a proximity sensor. Note that the sensor 66 may be disposed at a position other than that illustrated in FIG. 1 and the like, as long as it can detect that the wearer US has worn the virtual image display device 100, and may be disposed, for example, in the support device 100C, which is a wearing member.

[0047] When the display cumulative time of the display element 11 reaches a preset cumulative time (life time), the life management unit 61 operates the heat generation control unit 63c under the control of the life judgment unit 65 to pass a current through the heating element 63a connected to the dimming member 62 to heat the heating element 63a. The heat of the heating element 63a is transmitted to the dimming member 62, and the dimming member 62 becomes cloudy or deformed by the heat. The image or video displayed on the display element 11 passes through the dimming member 62 from the projection optical system 12 and is reflected by the see-through mirror 23 to be displayed as a virtual image, so that the virtual image becomes difficult to see due to the dimming caused by the dimming member 62, and the wearer US can be informed of the life of the display element 11, that is, the virtual image display device 100. This makes it possible to manage multiple virtual image display devices 100 without checking the life time of each one. As described above, when the display element 11 reaches its life, the image quality or video quality significantly deteriorates, so that it is no longer necessary to check the cumulative time for each one in managing the device.

[0048] The virtual image display device 100 of the first embodiment described above includes an image forming unit 11, a projection optical system 2 into which the image light ML formed by the image forming unit 11 is incident, a reflecting member 23 that reflects the image light ML emitted from the projection optical system 2 to project a virtual image, and a support member 51 that supports the image forming unit 11, the projection optical system 2, and the reflecting member 23, and at least a portion of the projection optical system 2 and the reflecting member 23 is an environmental member EM formed from an environmental material.

[0049] In the virtual image display 100, at least a part of the projection optical system 2 and the reflecting member 23 serving as optical members is made into an environmental member EM, so that the virtual image display 100 can be easily recycled when it is discarded.

[0050] Moreover, the virtual image display device 100 includes a dimming member 62 that is disposed on the optical path between the image forming unit 11 and the pupil position PP, has optical transparency, and can be changed to a dimming state in which the image light ML is dimmed under the influence of an external action, and the dimming member 62 is made of an environmentally friendly material. As a result, if the dimming member 62 is subjected to an action that changes the quality of the image light ML so as to dim it after the life time of the image forming unit 11 has elapsed, the projected virtual image becomes difficult to see, and even a general user can easily determine that the life time has been reached. Furthermore, by forming the dimming member 62 from an environmentally friendly material, it is possible to easily regenerate the virtual image display device 100 when it is disposed of.

[0051] As described above, in the virtual image display device 100, the components of the virtual image display device 100, specifically, the projection optical system 2, the reflecting member 23, or the dimming member 62, are made of the environmental member EM or environmental material, and the environmental member EM is made separable from the virtual image display device 100, which facilitates environmentally friendly design such as reuse, recycling, and sorting. In addition to regenerating or reusing the environmental member EM as is, if the environmental member EM or environmental material is configured so that a functional film or the like can be peeled off, or the environmental member EM or environmental material itself is configured so that it can be peeled off from a base material or the like, then it can be easily separated and regenerated or reused.

[0052] Second Embodiment Hereinafter, a virtual image display device according to a second embodiment of the present invention will be described. Note that the virtual image display device of the second embodiment is a partial modification of the virtual image display device of the first embodiment, and a description of the common parts will be omitted.

[0053] FIG. 7 is a side cross-sectional view for explaining the internal structure of the virtual image display device 100 of the second embodiment. As shown in FIG. 7, the virtual image display device 100 includes a display element 11 and an imaging optical system 920. The imaging optical system 920 is an off-axis optical system, but unlike the first embodiment, the optical path extends laterally while being reflected. The imaging optical system 920 is a light guide optical device, and includes a projection lens 21 and a light guide 70. In this embodiment, the projection lens 21 corresponds to the projection optical system 2, and the light guide 70 corresponds to the reflecting member. The light guide 70 is formed by bonding a light guide member 71 and a light transmitting member 72 via an adhesive layer CC. The light guide member 71 and the light transmitting member 72 are formed of a resin material that exhibits high light transmittance in the visible range. Specifically, the light guide member 71 and the light transmitting member 72 are environmental members EM formed of environmental materials. Note that either the light guide member 71 or the light transmitting member 72 may be the environmental member EM. The light guide member 71 has first to fifth surfaces S11 to S15, of which the first and third surfaces S11, S13 are parallel planes, and the second, fourth, and fifth surfaces S12, S13, S15 are generally convex optical surfaces, for example, free curved surfaces. The light transmitting member 72 has first to third transmitting surfaces S21 to S23, of which the first and third transmitting surfaces S21, S23 are parallel planes, and the second transmitting surface S22 is generally concave optical surface, for example, free curved surfaces. The second surface S12 of the light guide member 71 and the second transmitting surface S22 of the light transmitting member 72 have the same shape obtained by inverting the concave and convex shapes, and a partial reflection surface MC is formed on one surface of both surfaces.

[0054] As shown in an enlarged view in FIG. 8, the light guide 70 has a film 124 having a mirror film 23c peelably attached between the light guide member 71 and the light transmitting member 72. This allows the half mirror portion, which is a functional film, to be easily removed from the light guide 70 when the virtual image display device 100 is discarded, and allows the light guide member 71 and the light transmitting member 72, which are environmental members EM, to be easily recycled. In this embodiment, in the light guide 70 corresponding to the reflecting member, the main body of the light guide member 71 and the light transmitting member 72 corresponds to the base material. The mirror film 23c is formed on one surface of the film 124 by deposition or the like. On both sides of the film 124, double-sided adhesive OCA tapes 125 and 126 are provided. That is, the adhesive layer CC between the light guide member 71 and the light transmitting member 72 is arranged in the order of the first OCA tape 125, the mirror film 23c, the film 124, and the second OCA tape 126 from the light guide member 71 side. The mirror film 23c corresponds to the partially reflecting surface MC shown in FIG. 7. In addition, the film 124, the OCA tapes 125 and 126, the mirror film 23c, and the like shown in FIG. 8 are depicted as being thick for the sake of convenience of explanation, but in reality, they are relatively thin films.

[0055] Although not shown, the outer surface of the light guide 70 may be provided with a hard coat layer or an anti-reflection film.

[0056] The optical path of the image light ML will be briefly described below. The light guide member 71 guides the image light ML emitted from the projection lens 21 toward the wearer's eye EY by reflection on the first to fifth surfaces S11 to S15. Specifically, the image light ML from the projection lens 21 first enters the fourth surface S14 and is reflected on the fifth surface S15, which is the inner surface of the reflective film RM, enters the fourth surface S14 again from the inside and is totally reflected, enters the third surface S13 and is totally reflected, and enters the first surface S11 and is totally reflected. The image light ML totally reflected on the first surface S11 enters the second surface S12, partially transmits through the partially reflecting surface MC provided on the second surface S12, is partially reflected, and enters the first surface S11 again and passes through. The image light ML that passes through the first surface S11 enters the pupil position PP where the wearer's eye EY is located as a substantially parallel light beam. That is, the wearer observes an image using the image light ML as a virtual image.

[0057] The light guide 70 allows the wearer to view the image light ML through the light guide member 71, and allows the wearer to observe an external image with little distortion when the light guide member 71 and the light transmitting member 72 are combined. At this time, the third surface S13 and the first surface S11 are planes that are substantially parallel to each other (visual aberration is approximately 0), so that the external light OL hardly generates aberrations or the like. In addition, the third transmitting surface S23 and the first transmitting surface S21 are planes that are substantially parallel to each other. Furthermore, the third transmitting surface S23 and the first surface S11 are planes that are substantially parallel to each other, so that almost no aberrations or the like are generated. As a result, the wearer observes an external image without distortion through the light guide member 71 and the light transmitting member 72.

[0058] Although not shown in the drawings, in this embodiment, a light-reducing member may be provided on the exit side of the projection lens 21. The light-reducing member may have the same configuration as in the first embodiment.

[0059] Third Embodiment Hereinafter, a virtual image display device according to a third embodiment of the present invention will be described. Note that the virtual image display device of the third embodiment is a partial modification of the virtual image display device of the first embodiment, etc., and a description of the common parts will be omitted.

[0060] 9, in this embodiment, instead of the dimming member 62 shown in FIG. 2, a film 24 interposed in the mirror film 23c of the see-through mirror 23 may be used as the dimming member 162. That is, the dimming member 162 is peelably attached to the plate-shaped body 23b of the see-through mirror 23. This makes it possible to easily remove the dimming member 162 from the see-through mirror 23 when the virtual image display device 100 is discarded.

[0061] In this embodiment, the heating unit 163 is an external device. The heating unit 163 directly heats the light-reducing member 162 or irradiates the light-reducing member 162 with light. In the illustrated example, the heating unit 163 heats the light-reducing member 162 by irradiating the light-reducing member 162 with, for example, infrared light.

[0062] Similarly, in the virtual image display device 100 of the second embodiment, the film 124 constituting the adhesive layer CC of the light guide 70 may be used as a dimming member.

[0063] [Variations and Others] The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments and can be embodied in various forms without departing from the spirit of the present invention. For example, the following modifications are also possible.

[0064] In the above embodiment, the optical member serving as the environmental member EM may be at least a part of the projection optical system 2 and the see-through mirror 23 which is a reflecting member. In the members constituting the projection optical system 2, the optical member serving as the environmental member EM is a light-transmitting member through which the image light ML passes. Specifically, the projection lens 21 and the prism mirror 22 which constitute the projection optical system 2 may be the environmental member EM. In this case, the see-through mirror 23 does not have to be the environmental member EM, and the see-through mirror 23 may be made of a resin other than the environmental material or glass. In addition, all of the projection lens 21, the prism mirror 22, and the see-through mirror 23 may be the environmental member EM. Even when the projection lens 21 and the prism mirror 22 are the environmental members EM, it is preferable to attach a functional film such as an anti-reflection film or a reflection film to a base material via a peelable film, as in the case of the see-through mirror 23. In addition, the case 51 and the transmission window 53 which are the support members may be the environmental member EM. In this case, the transmission window 53 may be included in the members constituting the projection optical system 12.

[0065] In the above embodiment, the light-reducing member 62 may be provided in the projection lens 21 or the prism mirror 22 of the projection optical system 2. In this case, for example, a film-like light-reducing member is attached to the optical surface, similar to the see-through mirror 23. Also, the transmission window 53 or the plate-like body 23b of the see-through mirror 23 may be used as the light-reducing member 62. In this case, since the light-reducing member 62 is relatively thick, the light-reducing member 62 is made opaque when the image light ML is changed so as to be reduced in light. Also, although one light-reducing member 62 is provided, two or more light-reducing members may be provided.

[0066] In the above embodiment, the light reducing member 62 may be provided in both the first display device 100A and the second display device 100B, or may be provided in only one of the first display device 100A and the second display device 100B.

[0067] In the above embodiment, the life counting unit 64 does not need to be provided, and the life counting unit 64 may be managed by an external device.

[0068] In the above embodiment, the heating section 63 may be a light source such as a laser, and may locally heat the light reducing member 62 .

[0069] In the above embodiment, the virtual image display device 100 does not need to be provided with the light reducing member 62 .

[0070] In the above embodiment, the virtual image display 100 does not need to be provided with the sensor 66 for detecting whether the virtual image display 100 is being worn.

[0071] In the above embodiment, the virtual image display device 100 does not need to use at least a part of the projection optical system 2 and the see-through mirror 23, which is a reflective member, as the environmental member EM.

[0072] In the above embodiment, the heat generation control unit 63c, the life count unit 64, and the life determination unit 65 are attached to the display control device 88, but they may be configured as separate circuits.

[0073] In the first display device 100A, the projection lens 21 is configured with three lenses, but may be configured with one, two, or four or more lenses. Also, the projection lens 21 does not have to be provided in the first display device 100A.

[0074] A dimming device that adjusts light by limiting the light transmitted through the see-through mirror 23 can be attached to the outside world side of the see-through mirror 23. The dimming device adjusts the transmittance electrically, for example. As the dimming device, a mirror liquid crystal, an electronic shade, etc. can be used. The dimming device may adjust the transmittance according to the illuminance of outside light.

[0075] In a specific embodiment, the virtual image display device comprises an image forming unit, a projection optical system into which image light formed by the image forming unit is incident, and a reflective member that reflects the image light emitted from the projection optical system to project a virtual image, and at least a portion of the projection optical system and the reflective member are environmental members formed from environmental materials.

[0076] In the virtual image display device, at least a part of the projection optical system and the reflecting member serving as the optical members is made to be an environmental member, so that the virtual image display device can be easily recycled when it is discarded.

[0077] In a specific aspect, the environmental material of the environmental component is a biomass plastic.

[0078] In a specific aspect, the environmental material of the environmental component is any one of amorphous polylactic acid, polyhydroxybutyric acid, bio-polyethylene, and bio-polyethylene terephthalate.

[0079] In a specific aspect, the reflective member includes a base material formed of an environmentally friendly material, and the half mirror is attached to the base material via a peelable film. In this case, when the virtual image display device is disposed of, the half mirror portion can be easily removed from the reflective member, and the base material, which is an environmentally friendly material, can be easily recycled.

[0080] In a specific aspect, the projector includes a light-reducing member that is disposed on an optical path between the image forming unit and the pupil position, has optical transparency, and is changeable to a light-reducing state in which the image light is reduced under the influence of an external action. In this case, if the light-reducing member is subjected to an action that alters the properties of the light-reducing member so as to reduce the image light after the lifetime of the image forming unit has elapsed, the projected virtual image becomes difficult to see, and even a general user can easily determine that the lifetime has been reached.

[0081] In a specific aspect, a support member is provided that supports the image forming unit, the projection optical system, and the reflecting member, and the light-reducing member is disposed on the support member on the optical path between the projection optical system and the reflecting member. In this case, the light-reducing member can be stably disposed.

[0082] In a specific aspect, the light reducing member is removably attached to a base material of the reflecting member. In this case, when the virtual image display device is to be disposed of, the light reducing member can be easily removed from the reflecting member.

[0083] In a specific aspect, the dimming member is made of an environmentally friendly material, which can facilitate recycling when the virtual image display device is disposed of.

[0084] In a specific aspect, the environmental material of the light reducing member is amorphous polylactic acid.

[0085] In a specific aspect, the thickness of the dimming member is 0.2 mm or less.

[0086] In a specific aspect, after the life time of the image forming unit has elapsed, the light-reducing member is made opaque by the heating unit, in which case the internal refractive index of the light-reducing member changes, the transmittance decreases, and the brightness of the image decreases, making it difficult to see the projected virtual image.

[0087] In a specific aspect, after the life time of the image forming unit has elapsed, the light-reducing member is deformed by the heating unit, in which case the internal refractive index of the light-reducing member changes, causing the image to become distorted and making the projected virtual image difficult to see.

[0088] In a specific aspect, the heating unit has a heating element connected to the light reducing member, and heats the heating element by passing an electric current through the heating element.

[0089] In a specific aspect, the heating unit is an external device, and directly heats the light-attenuating member or irradiates the light-attenuating member with light.

[0090] In a specific aspect, the present invention includes a life counting unit that accumulates the operating time of the image forming unit, and a life judging unit that judges whether the operating time accumulated by the life counting unit exceeds a predetermined life. When the operating time of the image forming unit reaches the predetermined time, the image forming unit reaches the end of its life, and the dimming member is altered to dim the image light. This makes it possible to manage a plurality of virtual image display devices without checking the life of each one.

[0091] In a specific aspect, the lifetime is the time it takes for the brightness of an image formed by the image forming unit to decrease by half.

[0092] In a specific aspect, a sensor is provided that detects that the wearer is wearing the device, and the image forming unit operates when the sensor detects that the wearer is wearing the device. In this case, the operation of the image forming unit and the wearer's wearing of the device can be linked, and the life of the image forming unit can be appropriately managed.

[0093] In a specific embodiment, the virtual image display device comprises an image forming unit, a projection optical system into which image light formed by the image forming unit is incident, a reflecting member that reflects the image light emitted from the projection optical system to project a virtual image, and a dimming member that is arranged on the optical path between the image forming unit and the virtual image, has optical transparency, and is changeable to a dimming state in which it dims the image light under the influence of an external action, and the dimming member is made of an environmentally friendly material.

[0094] In the above virtual image display device, if the light-reducing member is subjected to a change in quality to reduce the image light after the life time of the image forming unit has elapsed, the projected virtual image becomes difficult to see, and even general users can easily tell that the life time has been reached. In addition, by forming the light-reducing member from an environmentally friendly material, it is possible to easily recycle the virtual image display device when it is discarded.

[0095] AX...optical axis, CC...adhesive layer, EM...environmental member, EY...eye, MC...partially reflective surface, ML...image light, OL...external light, OS...off-axis optical system, PP...pupil position, RM...reflective film, US...wearer, 11...display element, 11a...display surface, 12...projection optical system, 20...imaging optical system, 21...projection lens, 21o...lens, 21p...lens, 21q...lens, 22...prism mirror, 22a...entrance surface, 22b...inner reflective surface, 22c...exit surface, 23...see-through mirror, 23...reflective member, 23a...reflective surface, 23b...plate-shaped body, 23c...mirror film, 23o...outer surface, 24...film, 25...OCA tape, 51...case, 51a...opening, 51b...upper cover, 5 1c...lower cover, 53...transparent window, 61...lifetime management section, 62...light-reducing member, 63...heating section, 63a...heating element, 63b...insulating member, 63c...heating control section, 64...lifetime counting section, 65...lifetime determination section, 66...sensor, 67...holding section, 70...light guide, 71...light guide member, 72...light-transmitting member, 80...circuit system, 85...accessory circuit, 88...display control device, 90...user terminal, 91...user terminal circuit, 100...virtual image display device, 100A, 100B...display device, 100C...support device, 102...display drive section, 103...appearance member, 124...film, 125, 126...OCA tape, 162...light-reducing member, 163...heating section, 920...imaging optical system

Claims

1. An image forming unit; a projection optical system into which image light formed by the image forming unit is incident; a reflecting member that reflects the image light emitted from the projection optical system to project a virtual image; Equipped with At least a part of the projection optical system and the reflecting member is an environmental member formed of an environmentally friendly material.

2. The virtual image display device according to claim 1 , wherein the environmental material of the environmental member is a biomass plastic.

3. The virtual image display device according to claim 2 , wherein the environmental material of the environmental member is any one of amorphous polylactic acid, polyhydroxybutyric acid, biopolyethylene, and biopolyethylene terephthalate.

4. The reflective member includes a substrate formed from the environmental member, The virtual image display device according to claim 1 , wherein a half mirror is attached to the base material via a peelable film.

5. 2. The virtual image display device according to claim 1, further comprising a dimming member that is arranged on an optical path between the image forming unit and a pupil position, has optical transparency, and is changeable to a dimming state in which the image light is dimmed under the influence of an external action.

6. a support member that supports the image forming unit, the projection optical system, and the reflecting member; The virtual image display device according to claim 5 , wherein the light reducing member is disposed on the support member on an optical path between the projection optical system and the reflecting member.

7. The virtual image display device according to claim 5 , wherein the light reducing member is removably attached to a base material of the reflecting member.

8. The virtual image display device according to claim 5 , wherein the light reducing member is made of an environmentally friendly material.

9. The virtual image display device according to claim 8 , wherein the environmental material of the light reducing member is amorphous polylactic acid.

10. The virtual image display device according to claim 5 , wherein the light reducing member has a thickness of 0.2 mm or less.

11. The virtual image display device according to claim 5 , wherein the light reducing member is made opaque by a heating section after a life time of the image forming section has elapsed.

12. The virtual image display device according to claim 5 , wherein the light reducing member is deformed by a heating section after a life time of the image forming section has elapsed.

13. The virtual image display device according to claim 11 , wherein the heating section has a heating element connected to the light reducing member, and heats the heating element by passing an electric current through the heating element.

14. The virtual image display device according to claim 11 , wherein the heating section is an external device and directly heats the light reducing member or irradiates the light reducing member with light.

15. a life counting unit that accumulates an operating time of the image forming unit; a lifespan determination unit that determines whether the operation time accumulated by the lifespan count unit has exceeded a predetermined lifespan; The virtual image display device according to claim 5 .

16. The virtual image display device according to claim 11 , wherein the life time is a time required for the luminance of the image formed by the image forming unit to be reduced by half.

17. Equipped with a sensor that detects that the wearer is wearing the device, The virtual image display device according to claim 16 , wherein the image forming unit operates when the sensor detects that the wearer is wearing the device.

18. An image forming unit; a projection optical system into which image light formed by the image forming unit is incident; a reflecting member that reflects the image light emitted from the projection optical system to project a virtual image; a light-reducing member that is disposed on an optical path between the image forming unit and the virtual image, has optical transparency, and is changeable to a light-reducing state in which the image light is reduced under the influence of an external action; Equipped with The light reducing member is made of an environmentally friendly material.

Images