Virtual image display device

Abstract

A virtual image display device improves perspective transmittance in an image display area. A virtual image display device (100A, 100B) is provided with: a light source (10); a light guide member (21); a ferroelectric liquid crystal panel (12) that is provided to the light guide member (21) and that is in a scattering state in which the illumination light (IL) is emitted to the outside of the light guide member (21) and in a transparent state in which the external light (OL) is allowed to pass through; a transmissive liquid crystal panel (22) that is in a display state in which the illumination light (IL) that has passed through the ferroelectric liquid crystal panel (12) is incident and image light (ML) is formed, and a non-display state in which the external light (OL) that has passed through the ferroelectric liquid crystal panel (12) is transmitted; a switching 1 / 2 wavelength plate (23) for switching the polarization direction of the incident light to a first direction and a second direction, which intersect each other, in accordance with the orientation direction of the liquid crystal, and allowing the incident light to pass through the first direction and the second direction; and a polarizing lens (50) that has refractive power for imaging the first polarized light (P1) in the first direction as a virtual image, and that passes through the second polarized light (P2) in the second direction.

Description

Technical Field

[0001] The present invention relates to a virtual image display device capable of observing a virtual image, and more particularly to a see-through virtual image display device capable of visually observing an external image. Background Art

[0002] As a see-through virtual image display device capable of visually observing the outside world, a device is known that includes: a liquid crystal panel having an image display area and a transparent display area formed so as to surround the image display area; and a light guide plate that guides backlight incident on an end portion from a light source. The light guide plate includes a light emitting area that irradiates the backlight to the image display area of the liquid crystal panel and a light transmitting area that transmits ambient light (Patent Document 1). This virtual image display device is configured such that ambient light reaches an observer from the light transmitting area of the light guide plate and the transparent display area of the liquid crystal panel, and during a period when the backlight is not irradiated to the image display area, the ambient light passes through the light emitting area of the light guide plate and the image display area of the liquid crystal panel and reaches the observer. With such a configuration, see-through display in which image light coincides with ambient light is achieved.

[0003] Patent Document 1: International Publication No. 2016 / 056298

[0004] In the above device, processing such as dot formation and coating of a scattering material is performed in the light emitting area of the light guide plate. Since the ambient light in the image display area of the liquid crystal panel passes through the processed light emitting area, the see-through transmittance near the center of the field of view corresponding to the image display area is reduced. In order to achieve see-through display with a high see-through transmittance near the center of the field of view, an optical system with a high see-through transmittance is additionally required, resulting in an increase in size. Summary of the Invention

[0005] A virtual image display device according to an aspect of the present invention includes, in order from the outside world: a light guide member that propagates illumination light from a light source; a ferroelectric liquid crystal panel that is provided on the light guide member, becomes a scattering state with respect to the illumination light, and becomes a transparent state with respect to external light; a transmissive liquid crystal panel that becomes a display state and a non-display state; a switchable 1 / 2 wavelength plate that switches the polarization direction of incident light to a first direction and a second direction that cross each other according to the alignment direction of the liquid crystal and allows it to pass through; and a polarization lens that has a refractive power to form a virtual image of the polarized light in the first direction and allows the polarized light in the second direction to pass through. When the transmissive liquid crystal panel is in the display state, the switchable 1 / 2 wavelength plate causes the image light from the transmissive liquid crystal panel to enter the polarization lens as polarized light in the first direction. When the transmissive liquid crystal panel is in the non-display state, the switchable 1 / 2 wavelength plate causes the external light that has passed through the transmissive liquid crystal panel to enter the polarization lens as polarized light in the second direction. Brief Description of the Drawings

[0006] Figure 1 It is an external perspective view showing the wearing state of the virtual image display device of the first embodiment.

[0007] Figure 2 It is a conceptual perspective view showing the optical structure of the virtual image display device.

[0008] Figure 3 It is an enlarged side cross-sectional view showing the optical structure of the virtual image display device.

[0009] Figure 4 It is a diagram showing the state of light passing through the display optical system.

[0010] Figure 5 It is a diagram showing the operation of the virtual image display device.

[0011] Figure 6 It is an enlarged side cross-sectional view showing the virtual image display device of the second embodiment.

[0012] Figure 7 It is a diagram showing the state of light passing through the display optical system.

[0013] Figure 8 It is a diagram showing the operation of the virtual image display device.

[0014] Figure 9 It is an enlarged side cross-sectional view showing the virtual image display device of the third embodiment.

[0015] Figure 10 It is an enlarged side cross-sectional view showing the virtual image display device of the third embodiment.

[0016] Figure 11 It is a diagram showing the pixel structure.

[0017] Figure 12 It is a diagram showing the operation of the virtual image display device.

[0018] Figure 13 It is an enlarged side cross-sectional view showing the virtual image display device of the modification example.

[0019] Figure 14 It is a diagram showing the arrangement relationship between the pixels and the effective area of the ferroelectric liquid crystal panel.

[0020] Figure 15 It is an enlarged side cross-sectional view showing the virtual image display device of the fourth embodiment.

[0021] Figure 16 It is an enlarged side cross-sectional view showing the virtual image display device of the fourth embodiment.

[0022] Figure 17 It is a diagram showing the pixel structure.

[0023] Figure 18 This is an enlarged side sectional view of the virtual image display device showing a modified example.

[0024] Figure 19 This is a diagram showing the arrangement relationship between the pixels and the effective area of the ferroelectric liquid crystal panel.

[0025] Reference Numeral Explanation

[0026] AX: optical axis; EY: eye; IL, ILr, ILg, ILb: illumination light; ML: image light; OL: external light; PX: pixel; PX(D): display pixel; PX(T): transmission pixel; PXs: sub-pixel; QL: image light; RA: annular portion; SM1: R drive signal; SM2: G drive signal; SM3: B drive signal; SM4: W drive signal; SS1, SS2, SS3: flash signal; SW: on / off signal; US: wearer; Z1, Z2: sub-frame; 10: light source; 10b: B light-emitting element; 10r: R light-emitting element; 10g: G light-emitting element; 11: light guide plate; 12: ferroelectric liquid crystal panel; 12a: ferroelectric liquid crystal layer; 12b, 12c: substrates; 14: liquid crystal modulation component; 15: first polarizer; 16: second polarizer; 17a: liquid crystal layer; 17b, 17c: substrates; 18a: liquid crystal layer; 18b, 18c: substrates; 20: composite display component; 21: light guide component; 22: transmissive liquid crystal panel; 23: switch 1 / 2 wavelength plate; 31: liquid crystal layer; 32: common electrode; 33: pixel electrode; 35: black matrix; 41r, 41g, 41b: color filters; 50: polarization lens; 51: effective area; 52: transmission area; 80: control device; 81: drive circuit; 90: user terminal; 100A, 100B: virtual image display devices; 102: drive device; 102a, 102b: display drive units; 103a, 103b: display optical systems; 104: light shielding member; 104a, 104b: light transmissive covers; 200: head-mounted display device; 201: binocular display device. Detailed Embodiments

[0027] 〔First Embodiment〕

[0028] Hereinafter, with reference to Figures 1 to 5 , the virtual image display device according to the first embodiment of the present invention will be described.

[0029] Figure 1 This is a perspective view showing the wearing state of a head-mounted display, that is, a head-mounted display device 200. The head-mounted display device (hereinafter, also referred to as HMD) 200 is a binocular display device 201 that enables an observer or wearer US wearing it to recognize an image as a virtual image. In Figure 1Among them, X, Y, and Z are orthogonal coordinate systems. The +X direction corresponds to the lateral direction of the binocular arrangement of the eyes EY of the observer or wearer US wearing the HMD 200. The +Y direction is equivalent to the upward direction perpendicular to the lateral direction of the binocular arrangement of the eyes EY for the wearer US. The +Z direction is equivalent to the front direction or the front-facing direction for the wearer US. The ±Y direction is parallel to the plumb axis or the plumb direction.

[0030] The HMD 200 includes 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 temple arms 100C that support the virtual image display devices 100A and 100B, and a user terminal 90 that serves as an information terminal. The first virtual image display device 100A is composed of a first display driving unit 102a arranged at the upper part, a first display optical system 103a covering in front of the eyes, and a light-transmitting cover 104a covering the first display optical system 103a on the outside or front side. The second virtual image display device 100B is composed of a second display driving unit 102b arranged at the upper part, a second display optical system 103b covering in front of the eyes, and a light-transmitting cover 104b covering the second display optical system 103b on the outside or front side. The HMD 200 formed by combining the first virtual image display device 100A and the second virtual image display device 100B is also a generalized virtual image display device. The pair of temple arms 100C are wearing components or support devices 106 worn on the head of the wearer US, and support the upper end sides of the pair of display optical systems 103a and 103b and the upper end sides of the pair of light-transmitting covers 104a and 104b via the display driving units 102a and 102b that are integrated in appearance. The component formed by combining the pair of display driving units 102a and 102b is called the driving device 102. The component formed by combining the pair of light-transmitting covers 104a and 104b is called the light-shielding member 104.

[0031] Figure 2 is a perspective view illustrating the structure of the first display optical system 103a. The first display optical system 103a includes: a light source 10 that generates three-color light as illumination light in a time-division manner; a plate-shaped composite display member 20 that forms a two-dimensional image and emits image light ML; and a polarization lens 50 that functions as a lens for the image light ML. The light source 10 is also Figure 1A part of the first display driving unit 102a shown is arranged above the upper side of the light guide member 21 to supply illumination light to the light guide member 21 (to be described later) in the composite display member 20 from the upper end side. The light source 10 and the composite display member 20 are driven by the driving circuit 81 of the control device 80 of the first display driving unit 102a to operate, and at the same time, virtual image viewing based on the image light ML and external perspective viewing are realized. The composite display member 20 and the polarization lens 50 are arranged separately in the optical axis AX direction. In the first display optical system 103a, the distance between the eye EY and the polarization lens 50 is, for example, about 10 mm to 20 mm. In addition, the distance between the composite display member 20 and the polarization lens 50 is, for example, about 3 mm to 25 mm.

[0032] The light source 10 includes an R light-emitting element 10r that generates red light, a B light-emitting element 10b that generates blue light, and a G light-emitting element 10g that generates green light. The R light-emitting element 10r, the B light-emitting element 10b, and the G light-emitting element 10g are self-luminous elements, and can be, for example, organic light-emitting diodes (OLEDs), light-emitting diodes such as micro light-emitting diodes (μLEDs) formed of inorganic materials. The R light-emitting element 10r, the B light-emitting element 10b, and the G light-emitting element 10g are not limited to being assembled separately. That is, the light source 10 is a combination of one or more R light-emitting elements 10r, one or more B light-emitting elements 10b, and one or more G light-emitting elements 10g. In order to assist in the diffusion of the illumination light, a beam combiner including a beam splitter can be assembled between the light source 10 and the light guide member 21 of the composite display member 20.

[0033] The composite display member 20 is a plate-shaped member extending along the XY plane perpendicular to the optical axis AX, and sequentially includes a light guide member 21, a transmissive liquid crystal panel 22, and a switch 1 / 2 wavelength plate 23 from the outside. The composite display member 20 is a plate-shaped member formed by laminating the light guide member 21, the transmissive liquid crystal panel 22, and the switch 1 / 2 wavelength plate 23, and has a structure integrated by a frame (not shown). Here, the light guide member 21, the transmissive liquid crystal panel 22, and the switch 1 / 2 wavelength plate 23 are fixed to each other in a state where a predetermined interval is provided and they are arranged in the vicinity. In addition, the transmissive liquid crystal panel 22 includes a plurality of pixels PX arranged in a matrix along the XY plane (refer to Figure 3 ).

[0034] The polarization lens 50 is disposed on the front side, i.e., the -Z side, of the composite display component 20 and covers in front of the eyes. More specifically, the polarization lens 50 is disposed on the opposite side of the transmissive liquid crystal panel 22 so as to face the switchable 1 / 2 wavelength plate 23 in the composite display component 20. The polarization lens 50 is a plate-like component extending along the XY plane. The action of the polarization lens 50 varies according to the polarization direction of the incident light. The polarization lens 50 functions as a lens with respect to the image light ML emitted from the composite display component 20. That is, the polarization lens 50 causes the multiple pixels constituting the transmissive liquid crystal panel 22 to be imaged in a unified manner, and enables the image formed on the transmissive liquid crystal panel 22 to be observed as a virtual image. On the other hand, the polarization lens 50 functions as a parallel flat plate with respect to the external light OL passing through the composite display component 20. Specifically, the polarization lens 50 is a liquid crystal lens and includes a plurality of circular annulus portions RA having different refractive index states. A set of annulus portions RA are symmetrically and concentrically arranged around the optical axis AX. Among a set of annulus portions RA, the peripheral annulus portion RA away from the optical axis AX has a narrower radial width centered on the optical axis AX compared to the central annulus portion RA through which the optical axis AX passes. That is, the closer to the periphery, the narrower the radial width of the annulus portion RA.

[0035] The second display optical system 103b is optically the same as the first display optical system 103a or is a left-right inversion of the first display optical system 103a, and detailed description thereof is omitted.

[0036] Refer to Figure 3 , the light source 10 generates three-color illumination lights ILr, ILg, and ILb as the illumination light IL in a time-sharing manner, and supplies the three-color illumination lights ILr, ILg, and ILb to the light guide component 21 of the composite display component 20. The three-color illumination lights IL are selected so as to become white light when they overlap.

[0037] The light guide component 21 is a component in which a ferroelectric liquid crystal panel 12 is fixed to a light guide plate 11. The illumination lights ILr, ILg, and ILb from the light source 10 are coupled into the light guide plate 11 from the upper end of the light guide plate 11. The light guide plate 11 causes the illumination lights ILr, ILg, and ILb incident from the light source 10 to propagate downward.

[0038] The light guide plate 11 is composed of a flat plate with light transmissivity, and has a pair of flat surfaces 11a and 11b. On the flat surface 11b on the back side of the light guide plate 11, a ferroelectric liquid crystal panel 12 is adhered in a close contact state and fixed to the light guide plate 11. The ferroelectric liquid crystal panel 12 is provided attached to the light guide plate 11. That is, the ferroelectric liquid crystal panel 12 is provided in the light guide member 21 including the light guide plate 11. The ferroelectric liquid crystal panel 12 is a device that performs a switching-type operation according to a drive signal from the drive circuit 81, and can switch between a scattering state in which the illumination light IL (ILr, ILg, ILb) is emitted outside the light guide plate 11 and a transparent state in which the external light OL is transmitted and allowed to pass through. The ferroelectric liquid crystal panel 12 includes a ferroelectric liquid crystal layer 12a sandwiched between a pair of substrates 12b and 12c via a transparent electrode layer (not shown). The ferroelectric liquid crystal layer 12a is, for example, a reverse-mode polymer-dispersed liquid crystal, which becomes a transmissive state when no electric field is applied and becomes a scattering state when an electric field is applied (for example, refer to Japanese Patent Laid-Open No. 6-308543, etc.). The ferroelectric liquid crystal panel 12 can switch on and off not in units of pixels but over the entire surface. When the ferroelectric liquid crystal panel 12 is in the off state, the entire ferroelectric liquid crystal panel 12 becomes a transparent state, allowing the guiding of the illumination light IL in the light guide plate 11, and transmitting and allowing the external light OL incident on the ferroelectric liquid crystal panel 12 from the outside via the light guide plate 11 to pass through. On the other hand, when the ferroelectric liquid crystal panel 12 is in the on state, the entire ferroelectric liquid crystal panel 12 becomes a scattering state, preventing the total reflection of the illumination light IL in the light guide plate 11, causing the illumination light IL to be emitted outside the light guide plate 11, and restricting the passage of the external light OL incident on the ferroelectric liquid crystal panel 12 from the outside via the light guide plate 11. In addition, the ferroelectric liquid crystal layer 12a may become a transmissive state when an electric field is applied and become a scattering state when no electric field is applied.

[0039] The transmissive liquid crystal panel 22 is disposed on the face side, i.e., the -Z side, opposite to the light guide plate 11 and the ferroelectric liquid crystal panel 12. The transmissive liquid crystal panel 22 includes a liquid crystal modulation member 14 and a pair of polarizing plates 15 and 16 sandwiching the liquid crystal modulation member 14. In this case, the transmissive liquid crystal panel 22 or the liquid crystal modulation member 14 is, for example, a modulation element composed of an in-plane switching (IPS) type liquid crystal, and operates in units of pixels PX. The pixel PX does not have a filter and is colorless. The liquid crystal modulation member 14 does not rotate the polarization direction of the incident light when no electric field is applied, and rotates the polarization direction of the incident light when an electric field is applied. In this case, the pair of polarizing plates 15 and 16 are arranged such that the polarization directions are in a crossed direction, more specifically, in a perpendicular direction. That is, the image light ML or the external light OL emitted from the polarizing plate 16 through the transmissive liquid crystal panel 22 becomes the first polarized light P1 in the first direction with the polarization direction being longitudinal (refer to Figure 4)。The transmissive liquid crystal panel 22 can switch between on and off for each pixel PX according to a drive signal from the drive circuit 81, and can locally transmit incident light with any gray level between on and off. Therefore, the liquid crystal modulation member 14 has not only the liquid crystal layer 31, the common electrode 32, the pixel electrode 33, and the black matrix 35, but also scan lines, signal lines, switching elements, etc. which are not shown in the figure.

[0040] In addition, the transmissive liquid crystal panel 22 or the liquid crystal modulation member 14 may rotate the polarization direction of incident light when no electric field is applied, and may not rotate the polarization direction of incident light when an electric field is applied. In this case, the pair of polarizing plates 15, 16 are arranged such that the polarization directions are parallel to each other.

[0041] The switch 1 / 2 wavelength plate 23 is arranged on the opposite side of the light guide plate 11 facing the transmissive liquid crystal panel 22. The switch 1 / 2 wavelength plate 23 is a device that performs a switching operation according to a drive signal from the drive circuit 81, and switches the polarization direction of incident light between a first direction and a second direction that intersect each other according to the alignment direction of the liquid crystal and allows it to pass through. The switch 1 / 2 wavelength plate 23 includes a liquid crystal layer 17a sandwiched between a pair of substrates 17b, 17c via a transparent electrode layer not shown. The liquid crystal layer 17a is, for example, an IPS (in plane switching) type liquid crystal or the like, which does not rotate the polarization direction of incident light when no electric field is applied, and rotates the polarization direction of incident light when an electric field is applied. The switch 1 / 2 wavelength plate 23 can switch between on and off over the entire surface instead of for each pixel. When the switch 1 / 2 wavelength plate 23 is in the off state, the entire switch 1 / 2 wavelength plate 23 functions as a transparent flat plate, and allows the image light ML (i.e., the first polarized light P1 whose polarization direction is in the longitudinal first direction of ±Y direction) to pass through while maintaining its polarization direction (refer to Figure 4 the first region AR1). On the other hand, when the switch 1 / 2 wavelength plate 23 is in the on state, the entire switch 1 / 2 wavelength plate 23 functions as a 1 / 2 wavelength plate having a main axis in the middle of the X direction and the Y direction, rotates the polarization direction of the external light OL (i.e., the first polarized light P1 whose polarization direction is in the longitudinal first direction) by 90°, and emits it as the second polarized light P2 whose polarization direction is in the transverse second direction (refer to Figure 4 the second region AR2).

[0042] The polarization lens 50 arranged on the surface side of the switch 1 / 2 wavelength plate 23 includes a liquid crystal layer 18a sandwiched between a pair of substrates 18b, 18c via a transparent electrode layer not shown. As described above, the liquid crystal layer 18a includes a plurality of circular annular portions RA having different refractive index states around the optical axis AX along the XY plane (refer to Figure 2)。With respect to the first polarized light P1, i.e., the image light ML, whose polarization direction is the first direction, namely the ±Y direction, which is longitudinal and parallel to the paper surface, the refractive index of the liquid crystal layer 18a gradually decreases from the central annulus portion RA through which the optical axis AX passes to the outer annulus portion RA, and functions as a lens with positive refractive power. In addition, with respect to the second polarized light P2, i.e., the external light OL, whose polarization direction is the second direction, namely the ±X direction, which is transverse and perpendicular to the paper surface, the refractive index of each annulus portion RA of the liquid crystal layer 18a is the same, and functions as a parallel plate. As a result, the polarization lens 50 has the refractive power to form a virtual image of the first polarized light P1 in the first direction and allows the second polarized light P2 in the second direction to pass through.

[0043] Hereinafter, with reference to Figure 4 the state of light in the first display optical system 103a will be described. In Figure 4 , the first region AR1 shows the case where the first display optical system 103a is in the image observation period and the transmissive liquid crystal panel 22 is in the display state, and the second region AR2 shows the case where the first display optical system 103a is in the external light observation period and the transmissive liquid crystal panel 22 is in the non-display state. In the transmissive liquid crystal panel 22, the display state is a state in which the illumination light IL that has passed through the ferroelectric liquid crystal panel 12 is incident to form the image light ML, and the non-display state is a state in which the external light OL that has passed through the ferroelectric liquid crystal panel 12 is transmitted.

[0044] In the first stage during the image observation period, for example, the R light-emitting element 10r among the light-emitting elements 10r, 10g, 10b of the light source 10 emits light, and supplies the illumination light ILr as red light to the light guide member 21. At this moment, when the ferroelectric liquid crystal panel 12 is switched to the on state and becomes a scattering state, the illumination light ILr passes through the first polarizer 15 of the transmissive liquid crystal panel 22 and illuminates the liquid crystal modulation member 14 as the transverse polarized light, i.e., the second polarized light P2. That is, each colorless pixel PX constituting the transmissive liquid crystal panel 22 is illuminated. The image light QL that has passed through the liquid crystal modulation member 14 has its polarization plane rotated according to the drive signal, and after passing through the second polarizer 16, only the longitudinal polarized light, i.e., the first polarized light P1, is emitted as the image light ML(R). The image light ML(R) emitted from each pixel PX of the transmissive liquid crystal panel 22 is incident on the switch 1 / 2 wavelength plate 23. At this time, the switch 1 / 2 wavelength plate 23 is switched to the cut-off state and functions as a transparent plate, allowing the image light ML(R) of the first polarized light P1 to pass through while maintaining its polarization direction. The image light ML(R) of the first polarized light P1 that has passed through the switch 1 / 2 wavelength plate 23 forms a virtual image after passing through the polarization lens 50 that functions as a convex lens with respect to the first polarized light P1.

[0045] In the second stage during image observation, while the ferroelectric liquid crystal panel 12 is maintained in the ON state, the G light-emitting element 10g of the light source 10 emits light instead of the R light-emitting element 10r, and the illumination light ILg as green light is supplied to the light guide member 21 and emitted laterally from the light guide member 21. The image light QL that constitutes each pixel PX of the transmissive liquid crystal panel 22 or the liquid crystal modulation member 14 illuminated by the illumination light ILg is obtained by rotating the polarization plane of the illumination light ILg according to the drive signal, and each pixel PX of the transmissive liquid crystal panel 22 emits the image light ML(G) as the first polarized light P1. The switch 1 / 2 wavelength plate 23 maintains the cut-off state, and the image light ML(G) of the first polarized light P1 that has passed through the switch 1 / 2 wavelength plate 23 forms a virtual image via the polarization lens 50 that functions as a convex lens with respect to the first polarized light P1.

[0046] In the third stage during image observation, while the ferroelectric liquid crystal panel 12 is maintained in the ON state, the B light-emitting element 10b of the light source 10 emits light instead of the G light-emitting element 10g, and the illumination light ILb as blue light is supplied to the light guide member 21 and emitted laterally from the light guide member 21. The image light QL that constitutes each pixel PX of the transmissive liquid crystal panel 22 or the liquid crystal modulation member 14 illuminated by the illumination light ILb is obtained by rotating the polarization plane of the illumination light ILb according to the drive signal, and each pixel PX of the transmissive liquid crystal panel 22 emits the image light ML(B) as the first polarized light P1. The switch 1 / 2 wavelength plate 23 maintains the cut-off state, and the image light ML(B) of the first polarized light P1 that has passed through the switch 1 / 2 wavelength plate 23 forms a virtual image via the polarization lens 50 that functions as a convex lens with respect to the first polarized light P1.

[0047] During the above image observation period, that is, when the transmissive liquid crystal panel 22 is in the display state, the three-color image lights ML(R), ML(G), and ML(B) are sequentially displayed, and the switch 1 / 2 wavelength plate 23 makes the image light ML, that is, the first polarized light P1, from the transmissive liquid crystal panel 22 incident on the polarization lens 50, and the wearer US recognizes the color image.

[0048] On the other hand, during the external light observation, the light source 10 becomes a non-luminous state, i.e., an extinguished state, and stops supplying the illumination light IL to the light guide member 21. At this moment, when the ferroelectric liquid crystal panel 12 is switched to the cut-off state and becomes a transmissive state, the external light OL travels straight in a manner intersecting the light guide member 21 and is incident on the transmissive liquid crystal panel 22. At this time, each pixel PX of the transmissive liquid crystal panel 22 operates, for example, in the normally-off state and becomes the maximum transmissive state according to the drive signal. The second polarized light P2 in the external light OL incident on the pixel PX of the transmissive liquid crystal panel 22 travels straight in the transmissive liquid crystal panel 22, i.e., the pixel PX, and is converted into the first polarized light P1 and is incident on the switch 1 / 2 wavelength plate 23. At this time, the switch 1 / 2 wavelength plate 23 is switched to the on state and functions as a 1 / 2 wavelength plate, rotating the polarization direction of the external light OL as the first polarized light P1 by 90° and emitting it as the second polarized light P2. That is, when the transmissive liquid crystal panel 22 is in the non-display state, the switch 1 / 2 wavelength plate 23 causes the external light OL that has passed through the transmissive liquid crystal panel 22 to be incident on the polarization lens 50 as the second polarized light P2. The external light OL of the second polarized light P2 that has passed through the switch 1 / 2 wavelength plate 23 is incident on the eye EY via the polarization lens 50 that functions as a parallel plate for the second polarized light P2 without being affected by the imaging action of the composite display member 20 and the polarization lens 50.

[0049] Figure 5 It is a timing chart for explaining the display operation of the first virtual image display device 100A. The horizontal axis represents time, and from the top, it successively shows the blinking signal SS1 of the R light-emitting element 10r, the R drive signal SM1 for the red display applied to the liquid crystal modulation member 14, the blinking signal SS2 of the G light-emitting element 10g, the G drive signal SM2 for the green display applied to the liquid crystal modulation member 14, the blinking signal SS3 of the B light-emitting element 10b, the B drive signal SM3 for the blue display applied to the liquid crystal modulation member 14, the on / off signal SD of the ferroelectric liquid crystal panel (FLC) 12, and the on / off signal SW of the switch 1 / 2 wavelength plate (1 / 2λ) 23. The operation of the first virtual image display device 100A has a first sub-frame Z1 as a sub-frame for image observation and a second sub-frame Z2 as a sub-frame for external light observation in each frame.

[0050] In the first stage, i.e., the red display section Δ1, of the first sub-frame Z1 for image observation, the driving circuit 81 turns on the ferroelectric liquid crystal panel 12, lights up the R light-emitting element 10r, outputs an R driving signal SM1 for red display to each pixel PX of the transmissive liquid crystal panel 22, and turns off the switch 1 / 2 wavelength plate 23. As a result, the red image light ML(R) enters the eye EY, and a virtual image corresponding to the red pattern formed on the transmissive liquid crystal panel 22 can be observed through the polarization lens 50. In the second stage, i.e., the green display section Δ2, of the first sub-frame Z1, the driving circuit 81 maintains the on state of the ferroelectric liquid crystal panel 12, lights up the G light-emitting element 10g, outputs a G driving signal SM2 for green display to each pixel PX of the transmissive liquid crystal panel 22, and maintains the off state of the switch 1 / 2 wavelength plate 23. As a result, the green image light ML(G) enters the eye EY, and a virtual image corresponding to the green pattern formed on the transmissive liquid crystal panel 22 can be observed through the polarization lens 50. In the third stage, i.e., the blue display section Δ3, of the first sub-frame Z1, the driving circuit 81 maintains the on state of the ferroelectric liquid crystal panel 12, lights up the B light-emitting element 10b, outputs a B driving signal SM3 for blue display to each pixel PX of the transmissive liquid crystal panel 22, and maintains the off state of the switch 1 / 2 wavelength plate 23. As a result, the blue image light ML(B) enters the eye EY, and a virtual image corresponding to the blue pattern formed on the transmissive liquid crystal panel 22 can be observed through the polarization lens 50.

[0051] During the above first sub-frame Z1, i.e., the image observation period, the transmissive liquid crystal panel 22 in the display state or the transmissive state sequentially displays three-color image lights ML(R), ML(G), and ML(B), and the wearer US recognizes the color image.

[0052] In the second sub-frame Z2 for external light observation, the driving circuit 81 turns off the ferroelectric liquid crystal panel 12 to allow the external light OL to pass through, turns off the light source 10, outputs a driving signal for maximum transmission, for example, to each pixel PX of the transmissive liquid crystal panel 22, and turns on the switch 1 / 2 wavelength plate 23. At this time, the transmissive liquid crystal panel 22 is in a non-display state and a transmissive state. As a result, the external light OL traveling straight through the transmissive liquid crystal panel 22 and the polarization lens 50 enters the eye EY, and the outside image can be observed.

[0053] The structure of the first embodiment described above is an example. For example, the transmissive liquid crystal panel 22 does not need to operate in the normally-off mode and can also operate in the normally-on mode. In the case of operating in the normally-on mode, Figure 5The driving signals SM1, SM2, and SM3 shown are signals for inverting the gray scale, that is, signals for inverting the magnitude of the applied voltage. The transmissive liquid crystal panel 22 is not limited to the liquid crystal element of the IPS type, and may be other types of liquid crystal display elements such as a liquid crystal element of the TN type.

[0054] The switch 1 / 2 wavelength plate 23 can also rotate the polarization direction of the image light ML by 90° and emit it as the second polarized light P2, and transmit the external light OL as the first polarized light P1 while maintaining its polarization direction. In this case, the polarization lens 50 has a refractive power for imaging the image light ML of the second polarized light P2 as a virtual image, and directly transmits the external light OL of the first polarized light P1 as a parallel plate. In addition, the second polarized light P2 that is imaged by such a polarization lens 50 can be referred to as the first polarized light, and the first polarized light P1 that is not affected by the imaging action of the polarization lens 50 can be referred to as the second polarized light.

[0055] The light guide member 21 is not limited to fixing the ferroelectric liquid crystal panel 12 on the eye EY side of the light guide plate 11, and the ferroelectric liquid crystal panel 12 may also be fixed on the outside side of the light guide plate 11.

[0056] Figure 5 The first sub-frame Z1 and the second sub-frame Z2 shown are merely examples, and the time widths and time ratios of the sub-frames Z1 and Z2 can be adjusted by the control device 80 according to the external environment, for example, and can also be adjusted by the wearer US via the user terminal 90.

[0057] In the first sub-frame Z1, it is not necessary to make the pixels PX of the transmissive liquid crystal panel 22 in the maximum transmission state. By adjusting the transmittance of the pixels PX, the transmission intensity of the external light OL can be adjusted like an adjustable sunglasses. At this time, the transmittance may be adjusted not for the entire surface of the transmissive liquid crystal panel 22 but for a partial region.

[0058] The virtual image display devices 100A and 100B of the first embodiment described above sequentially include, from the outside: a light guide member 21 that propagates illumination light IL from a light source 10; a ferroelectric liquid crystal panel 12 that is disposed on the light guide member 21, becomes a scattering state with respect to the illumination light IL, and becomes a transparent state with respect to external light OL; a transmissive liquid crystal panel 22 that becomes a display state and a non-display state; a switch 1 / 2 wavelength plate 23 that switches the polarization direction of incident light to a first direction and a second direction that cross each other according to the alignment direction of the liquid crystal and allows it to pass through; and a polarization lens 50 that has a refractive power to form a virtual image of first polarized light P1 in the first direction and allows second polarized light P2 in the second direction to pass through. When the transmissive liquid crystal panel 22 is in the display state, the switch 1 / 2 wavelength plate 23 causes image light ML from the transmissive liquid crystal panel 22 to enter the polarization lens 50 as first polarized light P1 in the first direction. When the transmissive liquid crystal panel 22 is in the non-display state, the external light OL that has passed through the transmissive liquid crystal panel 22 enters the polarization lens 50 as second polarized light P2 in the second direction.

[0059] In the above virtual image display device, when the transmissive liquid crystal panel 22 is in the display state, the switch 1 / 2 wavelength plate 23 causes image light ML from the transmissive liquid crystal panel 22 to enter the polarization lens 50 as first polarized light P1 in the first direction. When the transmissive liquid crystal panel 22 is in the non-display state, the external light OL that has passed through the transmissive liquid crystal panel 22 enters the polarization lens 50 as second polarized light P2 in the second direction. Therefore, it is possible to switch between the image light ML and the external light OL and perform parallel observation. That is, the transmissive liquid crystal panel 22 can be used for image observation and external light observation by using the ferroelectric liquid crystal panel 12, and it is possible to suppress a decrease in the perspective transmittance while ensuring the display brightness.

[0060] In the virtual image display devices 100A and 100B of the first embodiment, the light source 10 alternately generates red, green, and blue illumination light. The transmissive liquid crystal panel 22 has colorless pixels PX, and modulates the light by passing through the pixels PX corresponding to the colors of the illumination light generated by the light source 10, and makes the pixels PX in a transmissive state when the light source 10 is not emitting light. In this case, in the first sub-frame Z1 that is a sub-frame for image observation, there are display intervals Δ1, Δ2, and Δ3 for displaying image lights ML(R), ML(G), and ML(B) of red, green, and blue, respectively.

[0061] 〔Second Embodiment〕

[0062] Hereinafter, the virtual image display device and the like of the second embodiment will be described. In addition, the virtual image display device of the second embodiment is obtained by partially changing the virtual image display device of the first embodiment, and the description of the parts common to the virtual image display device of the first embodiment will be omitted.

[0063] In Figure 6 In the first display optical system 103a or the first virtual image display device 100A shown, the transmissive liquid crystal panel 22 includes sub-pixels PXs, specifically, three types of sub-pixels PXs(R), PXs(G), and PXs(B). Although not shown in the figure, these sub-pixels PXs(R), PXs(G), and PXs(B) are arranged in a stripe pattern or a Bayer pattern to form pixels PX.

[0064] In the sub-pixels PXs(R) for red display, a red color filter 41r is disposed near the first polarizer 15. In the sub-pixels PXs(G) for green display, a green color filter 41g is disposed near the first polarizer 15. In the sub-pixels PXs(B) for blue display, a blue color filter 41b is disposed near the first polarizer 15.

[0065] Refer to Figure 7 , and the state of light in the first display optical system 103a will be described. In Figure 7 , the first region BR1 indicates a case where the first display optical system 103a is in an image observation period and the transmissive liquid crystal panel 22 is in a display state, and the second region BR2 indicates a case where the first display optical system 103a is in an external light observation period and the transmissive liquid crystal panel 22 is in a non-display state.

[0066] During the image observation period, by causing all the light-emitting elements 10r, 10g, and 10b of the light source 10 to emit light, white illumination light ILr, ILg, and ILb is supplied to the light guide member 21. At this moment, when the ferroelectric liquid crystal panel 12 is switched to the on state and becomes a scattering state, the second polarized light P2 in the illumination light ILr, ILg, and ILb illuminates the sub-pixels PXs(R), PXs(G), and PXs(B) that make up each pixel PX via the first polarizer 15 of the transmissive liquid crystal panel 22. As a result, the modulated first polarized light P1 of ML(R), ML(G), and ML(B) is emitted side by side from the transmissive liquid crystal panel 22. The image light ML(R), ML(G), and ML(B) emitted from each sub-pixel PXs(R), PXs(G), and PXs(B) of the transmissive liquid crystal panel 22 is incident on the switch 1 / 2 wavelength plate 23 in the cut-off state. The switch 1 / 2 wavelength plate 23 allows the image light ML(R), ML(G), and ML(B) of the first polarized light P1 to pass through while maintaining its polarization direction. The image light ML(R), ML(G), and ML(B) of the first polarized light P1 that has passed through the switch 1 / 2 wavelength plate 23 forms a virtual image via the polarization lens 50 that functions as a convex lens for the first polarized light P1.

[0067] On the other hand, during external light observation, when the light source 10 is in a non-luminous state, i.e., an extinguished state, and the supply of the illumination light IL to the light guide member 21 is stopped, and the ferroelectric liquid crystal panel 12 is switched to the cut-off state to become a transmissive state, the external light OL travels straight in a manner crossing the light guide member 21 and is incident on the transmissive liquid crystal panel 22. At this time, the sub-pixels PXs(R), PXs(G), and PXs(B) of each pixel PX constituting the transmissive liquid crystal panel 22, for example, become the maximum transmissive state. The second polarized light P2 in the external light OL travels straight through the transmissive liquid crystal panel 22, i.e., the sub-pixels PXs(R), PXs(G), and PXs(B), and is converted into the first polarized light P1, and is incident on the switch 1 / 2 wavelength plate 23. The switched 1 / 2 wavelength plate 23 in the on state rotates the polarization direction of the external light OL of the first polarized light P1 by 90° and emits it as the second polarized light P2. The external light OL of the second polarized light P2 that has passed through the switch 1 / 2 wavelength plate 23 is incident on the eye EY via the polarization lens 50 that functions as a parallel plate for the second polarized light P2 without being affected by the imaging action of the composite display member 20 and the polarization lens 50.

[0068] Figure 8 is a timing chart for explaining the display operation of the first virtual image display device 100A, corresponding to the timing chart shown in the first embodiment. In this case, instead of sequentially displaying the three-color image lights ML(R), ML(G), and ML(B) in a time-division manner, the three-color image lights ML(R), ML(G), and ML(B) are simultaneously displayed side by side. When the first virtual image display device 100A is in the external light observation period and the transmissive liquid crystal panel 22 is in the non-display state, the external light OL passes through the sub-pixels PXs(R), PXs(G), and PXs(B) of the transmissive liquid crystal panel 22 with good balance, so that an uncolored external image can be observed. Figure 5 In the present embodiment, the switch 1 / 2 wavelength plate 23 can also rotate the polarization direction of the image light ML by 90° and emit it as the second polarized light P2, and make the external light OL pass through as the first polarized light P1 while maintaining its polarization direction. In addition, the time widths and time ratios of the sub-frames Z1 and Z2 can be adjusted by the control device 80 according to the external environment, for example.

[0069] In the second sub-frame Z2, which is a sub-frame for external light observation, it is not necessary to make the sub-pixels PXs(R), PXs(G), and PXs(B) of each pixel PX constituting the transmissive liquid crystal panel 22 become the maximum transmissive state, and the transmittances of the sub-pixels PXs(R), PXs(G), and PXs(B) can be adjusted separately.

[0070]

[0071] ​In the virtual image display devices 100A and 100B of the second embodiment, the light source 10 generates white illumination lights ILr, ILg, and ILb. The transmissive liquid crystal panel 22 has red, green, and blue sub-pixels PXs(R), PXs(G), and PXs(B), and modulates the light corresponding to the light emission of the light source 10 through the sub-pixels PXs(R), PXs(G), and PXs(B) of each color. When the light source 10 does not emit light, the sub-pixels PXs(R), PXs(G), and PXs(B) of each color are in a transmissive state. In this case, in the first sub-frame Z1 that is a sub-frame for image viewing, the red, green, and blue image lights ML can be displayed simultaneously.

[0072] 〔Third Embodiment〕

[0073] Hereinafter, the virtual image display device and the like of the third embodiment will be described. In addition, the virtual image display device of the third embodiment is obtained by partially modifying the virtual image display device of the first embodiment, and the description of the parts common to the virtual image display device of the first embodiment will be omitted.

[0074] In Figure 9 and Figure 10 shown in the first display optical system 103a or the first virtual image display device 100A, the transmissive liquid crystal panel 22 includes two types of pixels PX(D) and PX(T). Neither of the pixels PX(D) and PX(T) has a color filter and is colorless. However, the display pixel PX(D) as one forms the image light ML, and the transmissive pixel PX(T) as the other is for external light OL and can transmit the external light OL.

[0075] For example, as Figure 11 shown, the colorless pixels PX(D) and PX(T) can be alternately arranged in a checkerboard pattern, but it is not limited thereto, and the rows of the display pixels PX(D) and the rows of the transmissive pixels PX(T) can be alternately repeated.

[0076] In Figure 9During the image observation period as shown, each light-emitting element 10r, 10g, 10b constituting the light source 10 emits light in sequence, and supplies illumination light ILr, ILg, ILb of each color to the light guide member 21. At this time, the ferroelectric liquid crystal panel 12 is in a scattering state in the on state, and the second polarized light P2 in the illumination light ILr, ILg, ILb illuminates each display pixel PX(D) via the first polarizing plate 15 of the transmissive liquid crystal panel 22. As a result, the modulated first polarized light P1, namely ML(R), ML(G), ML(B), is emitted from the transmissive liquid crystal panel 22 at different times in sequence. However, the transmissive pixel PX(T) is in a cut-off state and does not transmit the illumination light. The image light ML(R), ML(G), ML(B) emitted from each display pixel PX(D) of the transmissive liquid crystal panel 22 is incident on the switch 1 / 2 wavelength plate 23 in the cut-off state. The switch 1 / 2 wavelength plate 23 allows the image light ML(R), ML(G), ML(B) of the first polarized light P1 to pass through in sequence while maintaining its polarization direction. The image light ML(R), ML(G), ML(B) of the first polarized light P1 that has passed through the switch 1 / 2 wavelength plate 23 at different times in sequence forms a virtual image via the polarization lens 50 that functions as a convex lens for the first polarized light P1.

[0077] On the other hand, during Figure 10 the external light observation period as shown, when the light source 10 is in a non-light-emitting state, that is, an extinguished state, and the supply of the illumination light IL to the light guide member 21 is stopped, and the ferroelectric liquid crystal panel 12 is switched to the cut-off state to become a transmissive state, the external light OL travels straight in a manner intersecting the light guide member 21 and is incident on the transmissive liquid crystal panel 22. At this time, the display pixel PX(D) and the transmissive pixel PX(T) of the transmissive liquid crystal panel 22, for example, are in a maximum transmissive state, and the second polarized light P2 in the external light OL travels straight through the transmissive liquid crystal panel 22, that is, the pixels PX(D), PX(T), and is converted into the first polarized light P1 and is incident on the switch 1 / 2 wavelength plate 23. The switch 1 / 2 wavelength plate 23 in the on state rotates the polarization direction of the first polarized light P1 in the external light OL by 90° and emits it as the second polarized light P2. The external light OL of the second polarized light P2 that has passed through the switch 1 / 2 wavelength plate 23 is incident on the eye EY via the polarization lens 50 that functions as a parallel plate for the second polarized light P2 without being affected by the imaging action of the composite display member 20 and the polarization lens 50.

[0078] Figure 12 is a timing chart for explaining the display operation of the first virtual image display device 100A. Figure 12 is a diagram in which a W drive signal SM4 for the pixel PX(T) is added to the same drive signal as Figure 5 the above.

[0079] Figure 13Yes Figure 9 In a modified example of the first display optical system 103a shown in etc., the ferroelectric liquid crystal panel 12 has a striped effective region 51. The effective region 51 is unevenly formed on the light guide plate 11 or the light guiding member 21 and is formed only opposite to the display pixels PX(D). The effective region 51 has a ferroelectric liquid crystal layer 12a (see Figure 3 ), and can scatter the illumination lights ILr, ILg, and ILb. On the other hand, the transmissive region 52 formed between the effective regions 51 does not have the ferroelectric liquid crystal layer 12a, and allows the external light OL to go straight and transmit without scattering.

[0080] As Figure 14 shown, the transmissive liquid crystal panel 22 becomes a stripe array in which rows of display pixels PX(D) and rows of transmissive pixels PX(T) are alternately repeated. Correspondingly, the ferroelectric liquid crystal panel 12 also becomes a stripe array in which the effective regions 51 opposite to the rows of display pixels PX(D) and the transmissive regions 52 opposite to the rows of transmissive pixels PX(T) are alternately repeated. In addition, it is exemplified that the rows of pixels PX(D) and PX(T) extend in the horizontal direction or the X direction, but are not limited to extending in the horizontal direction or the X direction, and may also extend in the vertical direction or the Y direction.

[0081] In the virtual image display devices 100A and 100B of the third embodiment, the light source 10 alternately generates red, green, and blue illumination lights ILr, ILg, and ILb. The transmissive liquid crystal panel 22 has colorless display pixels PX(D) and colorless transmissive pixels PX(T), and modulates through the colorless display pixels PX(D) corresponding to the colors of the illumination lights ILr, ILg, and ILb generated by the light source 10. When the light source 10 does not emit light, the colorless transmissive pixels PX(T) are in a transmissive state. In this case, in the first sub-frame Z1 serving as a sub-frame for observing an image, there are display intervals Δ1, Δ2, and Δ3 for displaying image lights ML(R), ML(G), and ML(B) of red, green, and blue colors. In the second sub-frame Z2 serving as a sub-frame for observing external light, at least the colorless transmissive pixels PX(T) are operated, whereby time-division observation of a color image and a perspective image can be performed.

[0082] In Figure 13 the virtual image display device 100A of the modified example shown, when the light source 10 does not emit light, the transmissive liquid crystal panel 22 makes the colorless display pixels PX(D) in a transmissive state. In this case, in the second sub-frame Z2 serving as a sub-frame for observing external light, the display pixels PX(D) can be effectively utilized, and the perspective image can be brightened.

[0083] In Figure 13In the virtual image display device 100A of the modified example shown, the effective region 51 of the ferroelectric liquid crystal panel 12 is locally formed in a region opposed to the colorless display pixel PX(D) of the transmissive liquid crystal panel 22. Regarding the colorless transmissive pixel PX(T), it is not necessary to scatter the external light OL. By locally forming the effective region 51 of the ferroelectric liquid crystal panel 12 only in the region opposed to the colorless display pixel PX(D), the illumination lights ILr, ILg, and ILb can be selectively incident on the colorless display pixel PX(D).

[0084] 〔Fourth Embodiment〕

[0085] Hereinafter, the virtual image display device and the like of the fourth embodiment will be described. In addition, the virtual image display device of the fourth embodiment is obtained by locally modifying the virtual image display device of the second embodiment, and the description of the parts common to the virtual image display device of the second embodiment will be omitted.

[0086] In Figure 15 and Figure 16 shown in the first display optical system 103a or the first virtual image display device 100A, the transmissive liquid crystal panel 22 includes sub-pixels PXs, specifically, four types of sub-pixels PXs(R), PXs(G), PXs(B), and PXs(T). The three types of sub-pixels PXs(R), PXs(G), and PXs(B) each have color filters 41r, 41g, and 41b for the image light ML. The remaining one type of sub-pixel PXs(T) does not have a color filter and is for the external light OL.

[0087] Referring to Figure 17 the arrangement of the sub-pixels PXs will be described. In Figure 17 the first region CR1 represents an example of the arrangement of the sub-pixels PXs, and the second region CR2 represents another example of the arrangement of the sub-pixels PXs. The four types of sub-pixels PXs(R), PXs(G), PXs(B), and PXs(T) are arranged in an equal stripe pattern, but they may also be arranged in a Bayer pattern.

[0088] In Figure 15During the image observation period as shown, by causing all the light-emitting elements 10r, 10g, and 10b constituting the light source 10 to emit light, white illumination lights ILr, ILg, and ILb are supplied to the light guide member 21. At this moment, when the ferroelectric liquid crystal panel 12 is switched to the on state and becomes a scattering state, the second polarized light P2 in the illumination lights ILr, ILg, and ILb illuminates the sub-pixels PXs(R), PXs(G), PXs(B), and PXs(T) constituting each pixel PX via the first polarizer 15 of the transmissive liquid crystal panel 22. As a result, the modulated first polarized lights P1, ML(R), ML(G), and ML(B) are emitted side by side from the transmissive liquid crystal panel 22. However, the sub-pixel PXs(T) is in the cut-off state and does not transmit the illumination light. The image lights ML(R), ML(G), and ML(B) emitted from the sub-pixels PXs(R), PXs(G), and PXs(B) of the transmissive liquid crystal panel 22 are incident on the switch 1 / 2 wavelength plate 23 in the cut-off state. The switch 1 / 2 wavelength plate 23 allows the image lights ML(R), ML(G), and ML(B) of the first polarized light P1 to pass through while maintaining their polarization directions. The image lights ML(R), ML(G), and ML(B) of the first polarized light P1 that have passed through the switch 1 / 2 wavelength plate 23 form a virtual image via the polarization lens 50 that functions as a convex lens for the first polarized light P1.

[0089] On the other hand, during Figure 16 the external light observation period as shown, when the light source 10 is turned off, that is, in the extinguished state, and the supply of the illumination light IL to the light guide member 21 is stopped, and the ferroelectric liquid crystal panel 12 is switched to the cut-off state and becomes a transmissive state, the external light OL travels straight in a manner intersecting the light guide member 21 and is incident on the transmissive liquid crystal panel 22. At this time, the sub-pixels PXs(R), PXs(G), PXs(B), and PXs(T) constituting each pixel PX of the transmissive liquid crystal panel 22 are driven to, for example, the maximum transmission state, and the second polarized light P2 in the external light OL travels straight in the transmissive liquid crystal panel 22, that is, in the sub-pixels PXs(R), PXs(G), PXs(B), and PXs(T), and is converted into the first polarized light P1 and is incident on the switch 1 / 2 wavelength plate 23. The switched-on switch 1 / 2 wavelength plate 23 rotates the polarization direction of the first polarized light P1 of the external light OL by 90° and emits it as the second polarized light P2. The external light OL of the second polarized light P2 that has passed through the switch 1 / 2 wavelength plate 23 is incident on the eye EY via the polarization lens 50 that functions as a parallel plate for the second polarized light P2 without being affected by the imaging action of the composite display member 20 and the polarization lens 50.

[0090] Figure 18 is Figure 15In a modified example of the first display optical system 103a shown in etc., the ferroelectric liquid crystal panel 12 has a stripe-shaped effective region 51. The effective region 51 is formed only in opposition to the display sub-pixels PXs(R), PXs(G), and PXs(B) in each pixel PX. The effective region 51 has a ferroelectric liquid crystal layer 12a (refer to Figure 3 ), and is capable of scattering the illumination lights ILr, ILg, and ILb. On the other hand, the transmissive region 52 formed between the effective regions 51 does not have the ferroelectric liquid crystal layer 12a, and allows the external light OL to travel straight and transmit without scattering.

[0091] As Figure 19 shown, the transmissive liquid crystal panel 22 becomes a stripe array in which three rows of sub-pixels PXs(R), PXs(G), and PXs(B) and one row of sub-pixels PXs(T) are alternately repeated. Correspondingly, the ferroelectric liquid crystal panel 12 also becomes a stripe array in which the effective regions 51 opposed to the three rows of sub-pixels PXs(R), PXs(G), and PXs(B) and the transmissive regions 52 opposed to the rows of sub-pixels PXs(T) are alternately repeated.

[0092] In the virtual image display devices 100A and 100B of the fourth embodiment, the light source 10 generates white illumination lights ILr, ILg, and ILb. The transmissive liquid crystal panel 22 has red, green, and blue sub-pixels PXs(R), PXs(G), and PXs(B) and a colorless sub-pixel PXs(T). Modulation is performed using the sub-pixels PXs(R), PXs(G), and PXs(B) of each color corresponding to the light emission of the light source 10. When the light source 10 does not emit light, the colorless sub-pixel PXs(T) is made transmissive. In this case, in the first sub-frame Z1 as a sub-frame for observing an image, it is possible to simultaneously display red, green, and blue image lights ML(R), ML(G), and ML(B). In the second sub-frame Z2 as a sub-frame for observing external light, at least the colorless sub-pixel PXs(T) is operated, whereby time-division observation of a color image and a perspective image can be performed.

[0093] In Figure 18 a modified example of the virtual image display device 100A shown in etc., when the light source 10 does not emit light, the transmissive liquid crystal panel 22 makes the sub-pixels PXs(R), PXs(G), and PXs(B) of each color transmissive. In this case, in the second sub-frame Z2 as a sub-frame for observing external light, it is possible to effectively use the sub-pixels PXs(R), PXs(G), and PXs(B) of each color, and the perspective image can be brightened.

[0094] Modified examples and others

[0095] The present invention has been described based on the above embodiments, but the present invention is not limited to the above embodiments and can be implemented in various ways without departing from its gist. For example, the following modifications can also be made.

[0096] The liquid crystal lens serving as the polarization lens 50 is not limited to including the annular zone portion RA. As the polarization lens 50, various configurations that have a lens effect on specific polarized light can be adopted.

[0097] The above assumes that the HMD 200 is used while being worn on the head, but the above virtual image display devices 100A and 100B can also be used as a hand-held display that is peeked at like a binocular without being worn on the head. That is, in the present invention, the head-mounted display also includes a hand-held display.

[0098] The virtual image display device in a specific mode sequentially includes, from the outside: a light guide member that propagates illumination light from a light source; a ferroelectric liquid crystal panel that is disposed on the light guide member, becomes a scattered state for the illumination light, and becomes a transparent state for external light; a transmissive liquid crystal panel that becomes a display state and a non-display state; a switch 1 / 2 wavelength plate that switches the polarization direction of incident light to a first direction and a second direction that cross each other according to the alignment direction of the liquid crystal and allows it to pass through; and a polarization lens that has a refractive power to form a virtual image of the polarized light in the first direction and allows the polarized light in the second direction to pass through. When the transmissive liquid crystal panel is in the display state, the switch 1 / 2 wavelength plate makes the image light from the transmissive liquid crystal panel enter the polarization lens as polarized light in the first direction. When the transmissive liquid crystal panel is in the non-display state, the switch 1 / 2 wavelength plate makes the external light that has passed through the transmissive liquid crystal panel enter the polarization lens as polarized light in the second direction.

[0099] In the above virtual image display device, when the transmissive liquid crystal panel is in the display state, the switch 1 / 2 wavelength plate makes the image light from the transmissive liquid crystal panel enter the polarization lens as polarized light in the first direction. When the transmissive liquid crystal panel is in the non-display state, the external light that has passed through the transmissive liquid crystal panel is made to enter the polarization lens as polarized light in the second direction. Therefore, it is possible to switch between the image light and the external light and perform observation in parallel. That is, it is possible to use the transmissive liquid crystal panel for image observation and external light observation by using the ferroelectric liquid crystal panel, and it is possible to suppress a decrease in the perspective transmittance while ensuring the brightness of the display.

[0100] In the virtual image display device in a specific mode, the light source alternately generates red, green, and blue illumination light. The transmissive liquid crystal panel has colorless pixels and modulates the pixels corresponding to the color of the illumination light generated by the light source. When the light source does not emit light, the pixels are made to be in a transmissive state. In this case, there are display intervals for each color of the image light that displays red, green, and blue in the sub-frame for image observation.

[0101] In the virtual image display device in a specific mode, a light source alternately generates red, green, and blue illumination lights. The transmissive liquid crystal panel has colorless display pixels and colorless transmissive pixels, and modulates the illumination light generated by the light source through the colorless display pixels corresponding to the color of the illumination light, and makes the colorless transmissive pixels in a transmissive state when the light source does not emit light. In this case, in the sub-frame for image observation, there are display intervals for displaying image lights of red, green, and blue of each color. In the sub-frame for external light observation, by at least operating the colorless transmissive pixels, time-division observation of a color image and a perspective image can be performed.

[0102] In the virtual image display device in a specific mode, the effective area of the ferroelectric liquid crystal panel is locally formed in the area opposed to the colorless display pixels of the transmissive liquid crystal panel. Regarding the colorless transmissive pixels, it is not necessary to scatter external light, and by only locally forming the effective area of the ferroelectric liquid crystal panel in the area opposed to the colorless display pixels, the illumination light can be selectively incident on the colorless display pixels.

[0103] In the virtual image display device in a specific mode, the transmissive liquid crystal panel makes the colorless display pixels in a transmissive state when the light source does not emit light. In this case, in the sub-frame for external light observation, the display pixels can be effectively utilized, and the perspective image can be brightened.

[0104] In the virtual image display device in a specific mode, a light source generates white illumination light. The transmissive liquid crystal panel has red, green, and blue sub-pixels, and modulates the illumination light generated by the light source through the sub-pixels of each color, and makes the sub-pixels of each color in a transmissive state when the light source does not emit light. In this case, in the sub-frame for image observation, the image lights of red, green, and blue can be simultaneously displayed.

[0105] In the virtual image display device in a specific mode, a light source generates white illumination light. The transmissive liquid crystal panel has red, green, blue, and colorless sub-pixels, and modulates the illumination light generated by the light source through the sub-pixels of each color, and makes the colorless sub-pixels in a transmissive state when the light source does not emit light. In this case, in the sub-frame for image observation, the image lights of red, green, and blue can be simultaneously displayed. In the sub-frame for external light observation, by at least operating the colorless sub-pixels, time-division observation of a color image and a perspective image can be performed.

[0106] In the virtual image display device in a specific mode, the effective area of the ferroelectric liquid crystal panel is locally formed in the area opposed to the colorless sub-pixels of the transmissive liquid crystal panel. For the colorless sub-pixels, it is not necessary to scatter external light, and by only locally forming the effective area of the ferroelectric liquid crystal panel in the area opposed to the sub-pixels of each color, the illumination light can be incident on the sub-pixels of each color.

[0107] In a virtual image display device according to a specific embodiment, when the light source does not emit light, the transmissive liquid crystal panel makes the sub-pixels of each color in a transmissive state. In this case, in the sub-frame for external light observation, the sub-pixels of each color can be effectively utilized, and the perspective image can be brightened.

[0108] In a virtual image display device according to a specific embodiment, the ferroelectric liquid crystal panel emits the illumination light to the outside of the light guide member in a scattering state, and transmits the external light in a transparent state.

[0109] In a virtual image display device according to a specific embodiment, colorless sub-pixels and sub-pixels of each color are arranged in a stripe shape or a Bayer shape together to form pixels.

[0110] In a virtual image display device according to a specific embodiment, the ferroelectric liquid crystal panel emits the illumination light to the outside of the light guide member in a scattering state, and transmits the external light in a transparent state.

[0111] In a virtual image display device according to a specific embodiment, the ferroelectric liquid crystal panel is adhered to one of a pair of planes of the light guide plate provided in the light guide member and is fixed to the light guide plate.

[0112] In a virtual image display device according to a specific embodiment, the transmissive liquid crystal panel makes the illumination light that has passed through the ferroelectric liquid crystal panel incident to form image light in a display state, and transmits the external light that has passed through the ferroelectric liquid crystal panel in a non-display state.

[0113] In a virtual image display device according to a specific embodiment, the transmissive liquid crystal panel has a liquid crystal modulation member and a pair of polarizing plates sandwiching the liquid crystal modulation member. According to the characteristics and driving method of the liquid crystal modulation member, the pair of polarizing plates are set to a direction in which the polarization directions cross, or a direction in which the polarization directions are parallel.

[0114] In a virtual image display device according to a specific embodiment, it further has a drive circuit that makes the light source, the ferroelectric liquid crystal panel, the transmissive liquid crystal panel, and the switch 1 / 2 wavelength plate operate in coordination.

Claims

1. A virtual image display device, characterized in that: From the outside, they have: a light guide member that transmits illumination light from a light source; a ferroelectric liquid crystal panel, which is provided on the light guide member and is in a scattering state with respect to the illumination light and in a transparent state with respect to external light; A transmissive liquid crystal panel that becomes a display state and a non-display state; a switch 1 / 2 wavelength plate that switches the polarization direction of incident light into a first direction and a second direction that intersect each other according to the orientation direction of the liquid crystal and allows the incident light to pass; and a polarizing lens having a refractive power for imaging the polarized light in the first direction into a virtual image and allowing the polarized light in the second direction to pass through; When the transmissive liquid crystal panel is in the display state, the switch 1 / 2 wavelength plate allows the image light from the transmissive liquid crystal panel to be incident on the polarization lens as polarized light in the first direction. When the transmissive liquid crystal panel is in the non-display state, the switch 1 / 2 wavelength plate allows the external light that has passed through the transmissive liquid crystal panel to be incident on the polarization lens as polarized light in the second direction.

2. The virtual image display device according to claim 1, wherein: The light source switches to generate red, green and blue illumination light, The transmissive liquid crystal panel has colorless pixels, and the illumination light generated by the light source is modulated by the pixels in accordance with the color of the illumination light, and the pixels are placed in a transmissive state when the light source does not emit light.

3. The virtual image display device according to claim 1, wherein: The light source switches to generate red, green and blue illumination light, The transmissive liquid crystal panel has colorless display pixels and colorless transmissive pixels. The colorless display pixels are modulated according to the color of the illumination light generated by the light source. When the light source does not emit light, the colorless transmissive pixels are put into a transmissive state.

4. The virtual image display device according to claim 3, wherein: The effective region of the ferroelectric liquid crystal panel is locally formed in a region facing the colorless display pixels of the transmissive liquid crystal panel.

5. The virtual image display device according to claim 3, wherein: When the light source does not emit light, the transmissive liquid crystal panel causes the colorless display pixels to be in a transmissive state.

6. The virtual image display device according to claim 1, wherein: The light source generates white illumination light, The transmissive liquid crystal panel has red, green, and blue sub-pixels, and the sub-pixels of each color are modulated in accordance with the light emitted by the light source. When the light source does not emit light, the sub-pixels of each color are placed in a transmissive state.

7. The virtual image display device according to claim 1, wherein: The light source generates white illumination light, The transmissive liquid crystal panel has red, green, blue and colorless sub-pixels, and the sub-pixels of each color are modulated in accordance with the light emitted by the light source. When the light source does not emit light, the colorless sub-pixels are placed in a transmissive state.

8. The virtual image display device according to claim 7, wherein: The effective area of ​​the ferroelectric liquid crystal panel is locally formed in a region facing the colorless sub-pixel of the transmissive liquid crystal panel.

9. The virtual image display device according to claim 7, wherein: When the light source does not emit light, the transmissive liquid crystal panel sets the sub-pixels of each color to a transmissive state.

10. The virtual image display device according to claim 6 or 7, wherein: The achromatic sub-pixels are arranged in a stripe pattern or a Bayer pattern together with the sub-pixels of each color to form a pixel.

11. The virtual image display device according to claim 1, wherein: The ferroelectric liquid crystal panel emits the illumination light to the outside of the light guide member in the scattering state, and transmits the external light in the transparent state.

12. The virtual image display device according to claim 1, characterized in that: The ferroelectric liquid crystal panel is attached to one of a pair of flat surfaces of a light guide plate provided in the light guide member and is fixed to the light guide plate.

13. The virtual image display device according to claim 1, wherein: The transmissive liquid crystal panel allows illumination light that has passed through the ferroelectric liquid crystal panel to enter in the display state to form image light, and allows the external light that has passed through the ferroelectric liquid crystal panel to pass through in the non-display state.

14. The virtual image display device according to claim 1, wherein: The transmissive liquid crystal panel includes a liquid crystal modulation component and a pair of polarizing plates sandwiching the liquid crystal modulation component.

15. The virtual image display device according to claim 1, wherein: The virtual image display device further includes a drive circuit that causes the light source, the ferroelectric liquid crystal panel, the transmissive liquid crystal panel, and the switching 1 / 2 wavelength plate to operate in a coordinated manner.

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