KR20200130046A - Multi-image display apparatus providing holographic image - Google Patents

Abstract

Provided is a multi-image display device capable of providing holographic images. The disclosed multi-image display device includes a light source, a spatial light modulator, and an optical system. The optical system is configured such that a travelling path of a reproduced first image includes a first optical path in a first direction, a second optical path in a second direction orthogonal to the first direction, and a third optical path in a third direction orthogonal to the first direction and the second direction, respectively, wherein the optical system is configured such that the first image and a second image provided from an optical path different from the travelling path of the first image are provided to a viewer along the third optical path. The present invention provides the multi-image display device which can be applied to implement augmented reality (AR) or mixed reality (MR).

Description

Multi-image display apparatus providing holographic image {Multi-image display apparatus providing holographic image}

The disclosed embodiments relate to, for example, a multi-image display device such as a symptom reality system, and more particularly, to a multi-image display device capable of providing a holographic image.

Recently, as electronic devices and display devices capable of implementing virtual reality (VR) have been developed, interest in this has increased. A technology capable of realizing augmented reality (AR) and mixed reality (MR) as the next stage of virtual reality (VR) is also being studied.

Augmented reality (AR) is a display technology that further increases the effect of reality by superimposing (combining) virtual objects or information on the environment of the real world, unlike virtual reality (VR) that presupposes a complete virtual world. to be. While virtual reality (VR) can be limitedly applied to fields such as games and virtual experiences, augmented reality (AR) has an advantage that it can be applied to various reality environments. In particular, augmented reality (AR) is drawing attention as a next-generation display technology suitable for a ubiquitous environment or an Internet of things (IoT) environment. Such augmented reality (AR) can be said to be an example of mixed reality (MR) in that the real world and additional information (virtual world) are mixed and displayed.

It provides a multi-image display device that can be applied to implement augmented reality (AR) or mixed reality (MR).

In particular, it provides a multi-image display device that improves the sense of reality by providing a holographic image.

According to an embodiment, a multi-image display device includes: a light source emitting light; A spatial light modulator that modulates the light emitted from the light source to reproduce a first image; And an optical system for transmitting the first image to an observer, wherein a traveling path of the reproduced first image is a first optical path along a first direction and a second sight along a second direction orthogonal to the first direction The optical system is configured to include a third optical path along a third direction orthogonal to the first and second directions, and the first image and a second image coming from a path different from the first image are 3 The optical system may be configured to be provided to an observer along the optical path.

The first image may be a virtual holographic image, and the second image may be an external image including an actual external view.

In one embodiment, the spatial light modulator may be a reflective spatial light modulator that reflects and modulates light emitted from the light source.

In one embodiment, the optical system includes: a first beam splitter that reflects light emitted from the light source to the spatial light modulator and transmits the light reflected from the spatial light modulator; A second beam splitter for transmitting light coming from the first beam splitter; A first mirror disposed to reflect light transmitted through the second beam splitter to the second beam splitter; A third beam splitter disposed under the second beam splitter; And a second mirror disposed to reflect light from the third beam splitter to the third beam splitter.

The second beam splitter may be configured to reflect light reflected from the first mirror to the third beam splitter.

The first beam splitter, the second beam splitter, and the third beam splitter may be transflective mirrors that reflect half of incident light and transmit the other half.

The first beam splitter, the second beam splitter, and the third beam splitter may be polarization beam splitters that reflect light having a first linearly polarized component and transmit light having a second linearly polarized component orthogonal to the first linearly polarized component. .

The optical system further includes a first quarter wave plate disposed between the second beam splitter and the first mirror, and a second quarter wave plate disposed between the third beam splitter and the second mirror. Can include.

The third beam splitter may be configured to reflect light coming from the second beam splitter and transmit light reflected from the second mirror.

The second mirror includes a first surface opposite to the third beam splitter and a second surface opposite to the first surface, and the second mirror reflects a first image incident on the first surface and the It may be configured to transmit a second image incident on the second surface.

The first beam splitter and the second beam splitter are polarizing beam splitters that reflect light having a first linearly polarized component and transmit light having a second linearly polarized component orthogonal to the first linearly polarized component, and the third beam splitter is a It may be a polarization beam splitter that transmits light having a first linearly polarized component and reflects light having a second linearly polarized component orthogonal to the first linearly polarized component.

The third beam splitter may be configured to transmit light coming from the second beam splitter and reflect light reflected from the second mirror.

The optical system may include: a first lens disposed between the spatial light modulator and the first beam splitter; A second lens disposed between the first beam splitter and the second beam splitter; And a third lens disposed between the second beam splitter and the third beam splitter.

The first lens and the second lens may be a convex lens, and the third lens may be a concave lens.

The optical system may further include a spatial filter disposed between the first beam splitter and the second beam splitter near a focal point of the first lens.

The first optical path is formed between the spatial light modulator and the first mirror, the second optical path is formed between the second beam splitter and the third beam splitter, and between the second mirror and the observer The third optical path may be formed.

The first optical path and the third optical path may have different positions in a height direction, and the second optical path may be vertically formed between the first optical path and the third optical path.

At least one of the first mirror and the second mirror may be a concave mirror.

The second mirror is a concave mirror, and the optical system may be configured such that a real image of the first image is formed between the focus of the second mirror and the second mirror.

At least one of the first mirror and the second mirror may be a concave mirror.

In another embodiment, the optical system includes: a first beam splitter that reflects light emitted from the light source to the spatial light modulator and transmits the light reflected from the spatial light modulator; A first mirror reflecting light from the first beam splitter; A second beam splitter disposed under the first mirror; And a second mirror disposed to reflect light from the second beam splitter to the second beam splitter.

The second beam splitter may be configured to reflect light from the first mirror and transmit light reflected from the second mirror.

For example, the first beam splitter and the second beam splitter may be polarizing beam splitters that reflect light having a first linearly polarized component and transmit light having a second linearly polarized component orthogonal to the first linearly polarized component.

In this case, the optical system may further include a half-wave plate disposed between the first beam splitter and the second beam splitter, and a quarter wave plate disposed between the second beam splitter and the second mirror. .

In addition, the first beam splitter is a polarization beam splitter that reflects light having a first linearly polarized component and transmits light having a second linearly polarized component that is orthogonal to the first linearly polarized component, and the second beam splitter is a first linearly polarized component It may be a polarization beam splitter that transmits light having and reflects light having a second linearly polarized component, and the optical system may further include a quarter wave plate disposed between the second beam splitter and the second mirror. have.

In addition, the second beam splitter may be configured to transmit light coming from the first mirror and reflect light reflected from the second mirror.

In another embodiment, the spatial light modulator may be a transmission type spatial light modulator that transmits and modulates light emitted from the light source.

In another embodiment, the optical system may include a second beam splitter for transmitting light coming from the spatial light modulator; A first mirror disposed to reflect light transmitted through the second beam splitter to the second beam splitter; A third beam splitter disposed under the second beam splitter; And a second mirror disposed to reflect light from the third beam splitter to the third beam splitter.

The optical system includes: a first lens and a second lens disposed between the spatial light modulator and the second beam splitter; A spatial filter disposed between the first lens and the second lens; And a third lens disposed between the second beam splitter and the third beam splitter.

The first optical path is formed between the light source and the first mirror, the second optical path is formed between the second beam splitter and the third beam splitter, and the second optical path is formed between the second mirror and the observer. 3 light paths can be formed.

The disclosed multi-image display apparatus provides a holographic image having a three-dimensional effect together with an actual external view, thereby providing a more realistic augmented reality experience. In addition, since the disclosed multi-image display device has a small form factor, miniaturization is possible. In addition, the disclosed multi-image display device can realize a relatively wide viewing angle of about 60 degrees.

1 is a perspective view schematically showing a configuration of a multi-image display device according to an exemplary embodiment.
FIG. 2 is a cross-sectional view taken along a direction showing an exemplary arrangement of some of the components of the multi-image display device shown in FIG.
FIG. 3 is a cross-sectional view taken along a different direction illustrating an arrangement of some other components among components of the multi-image display device illustrated in FIG. 1.
4 schematically shows the configuration of the multi-image display device shown in FIG. 1 from another direction.
5 and 6 schematically show a principle of adjusting the depth of a holographic image visible to an observer in the multi-image display device illustrated in FIG. 1.
7 is a graph exemplarily showing a relationship between a position change of an image formed around a spatial light modulator and a depth of a holographic image visible to an observer.
8 is a block diagram schematically illustrating a configuration of a multi-image display device according to another exemplary embodiment.
9 exemplarily shows an arrangement of some of the components of a multi-image display device according to another embodiment.
10 is a cross-sectional view illustrating an arrangement of some parts among parts of a multi-image display device according to another exemplary embodiment.
11 is a cross-sectional view illustrating an arrangement of some components among components of a multi-image display device according to another exemplary embodiment.
12 is a cross-sectional view illustrating an arrangement of some components among components of a multi-image display device according to another exemplary embodiment.
13 is a cross-sectional view illustrating an arrangement of some parts among parts of a multi-image display device according to another exemplary embodiment.
14 is a cross-sectional view illustrating an arrangement of some parts among parts of a multi-image display device according to another exemplary embodiment.
15 is a perspective view schematically illustrating a configuration of a multi-image display device according to another exemplary embodiment.
16 is a cross-sectional view taken along one direction illustrating an example of an arrangement of some parts among the parts of the multi-image display device illustrated in FIG. 15.
FIG. 17 is a cross-sectional view taken along one direction illustrating another example of an arrangement of some components among components of the multi-image display device illustrated in FIG. 15.
FIG. 18 is a cross-sectional view taken along a different direction showing an arrangement of some other components among the components of the multi-image display device illustrated in FIG. 15.
19 to 21 illustrate various electronic devices employing a multi-image display device according to embodiments.

Hereinafter, a multi-image display apparatus that provides a holographic image will be described in detail with reference to the accompanying drawings. In the following drawings, the same reference numerals refer to the same elements, and the size of each element in the drawings may be exaggerated for clarity and convenience of description. In addition, the embodiments described below are merely exemplary, and various modifications are possible from these embodiments. In addition, in the layer structure described below, the expression described as "top" or "top" may include not only those that are directly above/below/left/right in contact but also those that are above/below/left/right in a non-contact manner.

1 is a perspective view schematically showing a configuration of a multi-image display device according to an exemplary embodiment. Referring to FIG. 1, a multi-image display apparatus 100 according to an exemplary embodiment may include a light source 110, an optical system 120, and a spatial light modulator 130.

The light source 110 may be a coherent light source that emits coherent light. In order to provide light having high coherence, for example, a laser diode (LD) may be used as the light source 110. Also, the light source 110 may be a light emitting diode (LED). The light emitting diode has a lower spatial coherence than a laser, but if the light has only a certain degree of spatial coherence, it can be sufficiently diffracted and modulated by the spatial light modulator 130. Any other light source 110 can be used as long as it emits light having spatial coherence in addition to the light emitting diode.

In addition, in the embodiment illustrated in FIG. 1, the light source 110 may be a point light source emitting emitted light. A point light source such as an LED or LD may be directly disposed at the location of the light source 110 shown in FIG. 1, but for convenience of design, the point light source may be disposed elsewhere and transmit light through an optical fiber. For example, an end of the optical fiber may be disposed at the location of the light source 110 shown in FIG. 1. In addition, although only one light source 110 is shown in FIG. 1 for convenience, the light source 110 may include a plurality of laser diodes or light emitting diodes respectively providing red, green, and blue light.

The spatial light modulator 130 may form a hologram pattern according to a hologram data signal provided from an image processing apparatus (not shown), for example, a computer generated hologram (CGH) signal. As a result of the incident light emitted from the light source 110 and incident on the spatial light modulator 130 is diffracted by the hologram pattern formed by the spatial light modulator 130, a holographic image having a three-dimensional effect may be reproduced. The spatial light modulator 130 may use any of a phase modulator capable of performing only phase modulation, an amplitude modulator capable of performing only amplitude modulation, and a composite modulator capable of performing both phase modulation and amplitude modulation. In the embodiment illustrated in FIG. 1, the spatial light modulator 130 may be a reflective spatial light modulator that diffracts and modulates incident light while reflecting it. For example, the spatial light modulator 130 may use a liquid crystal on silicon (LCoS), a digital micromirror device (DMD), or a semiconductor modulator.

The optical system 120 serves to transmit a holographic image formed around the spatial light modulator 130 to an observer's eye. In addition, the optical system 120 may be configured to transmit a holographic image and an external view to the viewer's eyes. Characteristics of the multi-image display device 100 such as a viewing angle of a holographic image, the image quality, and the size of the multi-image display device 100 felt by the observer may vary according to the design of the optical system 120.

In the embodiment shown in FIG. 1, the optical system 120 reflects the light transmitted through the first beam splitter 121 and the second beam splitter 124 and the second beam splitter 124 disposed opposite to each other. 1 mirror 126, a third beam splitter 128 disposed under the second beam splitter 124, and a second mirror 129 that reflects the light reflected from the third beam splitter 128 again. can do.

The first beam splitter 121 may be disposed such that two different surfaces of the first beam splitter 121 face the light source 110 and the spatial light modulator 130, respectively. For example, the light source 110 may be disposed in the +z direction with respect to the first beam splitter 121, and the spatial light modulator 130 may be disposed in the -y direction with respect to the first beam splitter 121 have. The first beam splitter 121 is configured to reflect light emitted from the light source 110 to the spatial light modulator 130 and transmit the light reflected from the spatial light modulator 130 to the second beam splitter 124 Can be. Accordingly, the light reflected from the spatial light modulator 130 may pass through the first beam splitter 121 and travel toward the second beam splitter 124 in the +y direction.

The second beam splitter 124 and the first mirror 126 may be sequentially disposed along the +y direction. The second beam splitter 124 may be configured to transmit light reflected from the spatial light modulator 130 and reflect light reflected from the first mirror 126 in the -z direction, that is, downward in the drawing. Accordingly, light reflected by the spatial light modulator 130 may reach the first mirror 126 after passing through the first beam splitter 121 and the second beam splitter 124. Thereafter, the light is reflected by the first mirror 126 and then again reflected by the second beam splitter 124 to enter the third beam splitter 128.

The third beam splitter 128 may be disposed to face the second beam splitter 124 in the -z direction. In addition, the second mirror 129 may be disposed to face the third beam splitter 128 in the -x direction. The third beam splitter 128 may be configured to reflect light reflected from the second beam splitter 124 to the second mirror 129 and transmit the light reflected from the second mirror 129. Then, the light reflected from the second mirror 129 may pass through the third beam splitter 128 and reach the viewer's eye. In addition, the second mirror 129 may be configured to transmit light traveling in the +x direction from the outside. Then, the outside view may pass through the second mirror 129 and be visible to the observer's eyes.

The first to third beam splitters 121, 124, and 128 may be semi-transmissive mirrors that simply reflect half of the incident light and transmit the other half. When the first to third beam splitters 121, 124, and 128 are transflective mirrors, the first and second quarter wave plates 125a and 125b described below may be omitted from the optical system 120. have. However, in order to use light efficiently, the first to third beam splitters 121, 124, and 128 may be polarized beam splitters that transmit or reflect incident light according to the polarization state of the incident light.

FIG. 2 is a cross-sectional view taken along a direction of an exemplary arrangement of some of the components of the multi-image display apparatus 100 illustrated in FIG. 1. For example, FIG. 2 is an optical system 120 in a plane including a z-axis and a y-axis to specifically show the components from the spatial light modulator 130 to the first mirror 126 arranged along the +y direction. Is a cross-sectional view cut.

Referring to FIG. 2, the light source 110 is disposed to face the first surface 121a of the first beam splitter 121. Accordingly, the light emitted from the light source 110 is incident on the first surface 121a of the first beam splitter 121. The first beam splitter 121 is a polarization beam splitter that reflects light having a first linearly polarized component and transmits light having a second linearly polarized component orthogonal to the first linearly polarized component. Then, among the light emitted from the light source 110, light having a first linearly polarized component may be reflected by the first beam splitter 121, and light having a second linearly polarized component may pass through the first beam splitter 121. .

The light having the first linearly polarized light component reflected by the first beam splitter 121 is emitted through the second surface 121b of the first beam splitter 121 and then incident on the spatial light modulator 130. The spatial light modulator 130 is disposed to face the second surface 121b of the first beam splitter 121. In addition, the optical system 120 may further include a first lens 122a disposed between the second surface 121b of the first beam splitter 121 and the spatial light modulator 130. The light emitted from the light source 110 is a diverging beam whose beam diameter gradually increases along the traveling direction. The first lens 122a may convert light from the first beam splitter 121 into parallel light having a constant beam mirror. To this end, the first lens 122a is a convex lens. Accordingly, the spatial light modulator 130 is incident with the polarized light having a constant beam mirror.

The spatial light modulator 130 modulates and reflects incident light, and the modulated light interferes with each other to form a holographic image. In addition, when the light is modulated by the spatial light modulator 130, the light is rotated by 90 degrees, so that the light has a second linearly polarized component. In this way, the light containing the holographic image is incident on the second surface 121b of the first beam splitter 121 again. In this case, the light is focused while passing through the first lens 122a. Therefore, the beam diameter becomes smaller and smaller along the travel direction of the light. Light having the second linearly polarized light component passes through the first beam splitter 121 and is emitted to the third surface 121c of the first beam splitter 121 opposite to the second surface 121b. In addition, light may enter the first surface 124a of the second beam splitter 124.

Meanwhile, the optical system 120 may further include a spatial filter 123 and a second lens 122b disposed between the optical paths between the first beam splitter 121 and the second beam splitter 124. The spatial filter 123 serves to remove unnecessary light components other than the holographic image. The spatial filter 123 and the second lens 122b may be disposed near the focal point of the first lens 122a. In FIG. 2, it is shown that the spatial filter 123 is disposed first and the second lens 122b is disposed after the light traveling direction, but is not limited thereto. For example, the second lens 122b may be disposed first along the propagation direction of light, and the spatial filter 123 may be disposed behind.

The light focused by the first lens 122a becomes a diverging beam whose beam diameter gradually increases as it passes through the focus of the first lens 122a, and the second lens 122b is the first lens of the second beam splitter 124 It is possible to suppress an excessively large beam diameter of light incident on the surface 124a. For example, the second lens 122b may make light incident on the first surface 124a of the second beam splitter 124 into parallel light or a divergent beam whose beam diameter gradually increases. To this end, the second lens 122b is a convex lens.

The second beam splitter 124 is a polarization beam splitter that reflects light having a first linearly polarized component and transmits light having a second linearly polarized component orthogonal to the first linearly polarized component. Accordingly, the light of the second linearly polarized light component incident on the first surface 124a of the second beam splitter 124 from the first beam splitter 121 passes through the second beam splitter 124 and passes through the first surface 124a. It is emitted to the second surface 124b of the second beam splitter 124 opposite to. The first mirror 126 is disposed opposite the second surface 124b of the second beam splitter 124. Accordingly, light emitted to the second surface 124b of the second beam splitter 124 may enter the first mirror 126.

The optical system 120 may further include a first quarter wave plate 125a disposed in an optical path between the second surface 124b of the second beam splitter 124 and the first mirror 126. The first quarter wave plate 125a serves to delay incident light by a quarter wavelength of the incident light. Accordingly, light having a first linearly polarized component becomes light having a first circularly polarized component by the first 1/4 wave plate 125a, and light having a first circularly polarized component is a first 1/4 wave plate ( 125a) results in light having the first linearly polarized light component. In addition, light having a second linearly polarized component becomes light having a second circularly polarized component by the first 1/4 wave plate 125a, and light having a second circularly polarized component is a first 1/4 wave plate ( 125a) results in light having a second linearly polarized light component.

Light emitted to the second surface 124b of the second beam splitter 124 passes through the first 1/4 wave plate 125a and has a second circularly polarized light component. Light having the second circularly polarized light component is reflected by the first mirror 126 in the opposite direction, that is, 180 degrees with respect to the incident direction. At this time, the polarization component of the light reflected by the first mirror 126 is converted into a first circularly polarized light component. Then, the light has a first linearly polarized light component while passing through the first quarter wave plate 125a again. Thereafter, the light having the first linearly polarized component is incident on the second surface 124b of the second beam splitter 124 and is reflected by the second beam splitter 124.

The light reflected by the second beam splitter 124 is emitted to the third surface 124c of the second beam splitter 124. The optical system 120 may further include a third lens 127 disposed to face the third surface 124c of the second beam splitter 124. According to this embodiment, the first mirror 126 may be a concave mirror having a concave reflective surface. Accordingly, the first mirror 126 may make the reflected light into a converging beam whose beam diameter becomes smaller along the traveling direction. The third lens 127 serves to transform the converging beam into a diverging beam again to increase the viewing angle of the holographic image visible to the observer. To this end, the third lens 127 may be a concave lens.

FIG. 3 is a cross-sectional view taken along a different direction showing an arrangement of some other components among components of the multi-image display apparatus 100 illustrated in FIG. 1. For example, FIG. 3 is a cross-sectional view of the optical system 120 cut in a plane including the z-axis and the x-axis in FIG. 1 in order to specifically show the path of light from the second beam splitter 124 to the observer's eye to be. Since the cross-sectional view of FIG. 3 is rotated by 90 degrees with respect to the cross-sectional view of FIG. 2, the linearly polarized light component is displayed in FIG. For example, in FIG. 2, the first linearly polarized component is indicated by'⊙' and the second linearly polarized component is indicated by'↕', but in FIG. 3, the first linearly polarized component is indicated by'↕' and the second linearly polarized component is indicated by ' It is displayed as'⊙'.

Referring to FIG. 3, light of the first linearly polarized light component reflected by the second beam splitter 124 and passed through the third lens 127 enters the third beam splitter 128. Like the first and second beam splitters 121 and 124, the third beam splitter 128 reflects light having a first linearly polarized component and transmits light having a second linearly polarized component orthogonal to the first linearly polarized component. It is a polarizing beam splitter. In FIG. 2, the first and second beam splitters 121 and 124 are shown in a cube shape, and in FIG. 3, the third beam splitter 128 is shown in a flat plate shape, but is not limited thereto. For the first to third beam splitters 121, 124, and 128, a cube shape may be selected or a flat plate shape may be selected according to the need for assembling the optical system 120.

The light of the first linearly polarized component reflected by the third beam splitter 128 is incident on the second mirror 129. The optical system 120 may further include a second quarter wave plate 125b disposed in an optical path between the third beam splitter 128 and the second mirror 129. Accordingly, light of the first linearly polarized component is converted into light of the first circularly polarized component while passing through the second quarter wave plate 125b. Light having the first circularly polarized light component is reflected by the second mirror 129 in the opposite direction, that is, 180 degrees with respect to the incident direction. In this case, the polarization component of the light reflected by the second mirror 129 is converted into a second circular polarization component. Further, the light has a second linearly polarized light component while passing through the second quarter wave plate 125b again. Thereafter, the light having the second linearly polarized component passes through the third beam splitter 128 and enters the observer's eye E. According to the present embodiment, the second mirror 129 may be a concave mirror having a concave reflective surface for converging reflected light. Accordingly, the holographic image IMG1 may be provided to the pupil of the observer's eye E through the second mirror 129.

The second mirror 129 may also be a transflective mirror that transmits some of the incident light and reflects the other. Then, light containing the external foreground may pass through the second mirror 129 and the third beam splitter 128 and enter the observer's eye E as an external image IMG2. For example, the second mirror 129 includes a first surface S1 facing the third beam splitter 128 and a second surface S2 opposite to the first surface S1, and the first surface The holographic image IMG1 incident on (S1) may be reflected and the external image IMG2 incident on the second surface S2 may be transmitted.

Instead, the second mirror 129 may be a polarization-selective mirror that reflects light having a first circularly polarized light component and transmits light having a second circularly polarized light component. In this case, light of the first circularly polarized light component containing the holographic image IMG1 is reflected by the first surface S1 of the second mirror 129. On the other hand, the light of the second circularly polarized light component of the light containing the external image IMG2 passes through the second surface S2 of the second mirror 129 and then passes through the second quarter wave plate 125b. It has a second linearly polarized component. Then, the light containing the external image IMG2 converted into the second linearly polarized light component may pass through the third beam splitter 128 and enter the observer's eye E.

Instead, the second mirror 129 may be configured to reflect light incident on the first surface S1 and transmit light incident on the second surface S2. In this case, the light containing the external image IMG2 incident on the second surface S2 of the second mirror 129 passes through the second mirror 129 and the second quarter wave plate 125b, It is incident on the third beam splitter 128. In addition, among the light containing the external image IMG2, light having a second linearly polarized component may pass through the third beam splitter 128 and enter the observer's eye E.

As described in FIGS. 2 and 3, the optical system 120 may include optical paths having three different directions. For example, the optical system 120 includes a first optical path along the y direction between the spatial light modulator 130 and the first mirror 126, and between the second beam splitter 124 and the third beam splitter 128. and a second optical path along the z direction, and a third optical path along the x direction between the second mirror 129 and the observer. The direction of the first optical path, the direction of the second optical path, and the direction of the third optical path are orthogonal to each other. In addition, the first optical path, the second optical path, and the third optical path have different positions in the height direction. For example, the third optical path is positioned lower than the first optical path, and the second optical path is formed vertically between the first optical path and the third optical path. Through the arrangement of the optical paths, the form factor of the multi-image display apparatus 100 can be made small. Finally, the holographic image IMG1 and the external image IMG2 may be provided to the observer's eye E along the third optical path.

According to this embodiment, a holographic image IMG1 reproduced by the spatial light modulator 130 and an external image IMG2 containing an actual exterior view may be simultaneously provided to the observer's eyes. Then, the user can see a holographic image (IMG1) containing virtual reality or virtual information and a background subject of the real world that the user is actually facing. Accordingly, the multi-image display apparatus 100 according to the present exemplary embodiment can be applied to implement an augmented reality (AR) or mixed reality (MR). In this case, the multi-image display apparatus 100 according to the present exemplary embodiment may be a near-eye AR display apparatus.

In addition, FIG. 4 schematically shows the configuration of the multi-image display apparatus 100 shown in FIG. 1 from another direction. For example, FIG. 4 shows the multi-image display apparatus 100 in FIG. 1 viewed from the top in the -z axis direction, and for convenience, some components are shown in a cross-sectional shape. Since the direction shown in FIG. 4 is rotated by 90 degrees with respect to the direction shown in FIG. 2, in FIG. 4, the linearly polarized component is displayed opposite to that of FIG. 2. For example, in FIG. 2, the first linearly polarized component is indicated by'⊙' and the second linearly polarized component is indicated by'↕', but in FIG. 4, the first linearly polarized component is indicated by'↕' and the second linearly polarized component is indicated by ' It is displayed as'⊙'.

Referring to FIG. 4, the light source 110 may be disposed facing the upper surface of the first beam splitter 121, that is, the center of the first surface 121a. As previously described, the light emitted from the light source 110 is the first beam splitter 121, the first lens 122a, the spatial light modulator 130, the first lens 122a, and the first beam splitter 121 ), spatial filter 123, second lens 122b, second beam splitter 124, first quarter wave plate 125a, first mirror 126, first quarter wave plate 125a ), a second beam splitter 124, a third lens 127 (see FIGS. 2 and 3), a third beam splitter 128 (see FIG. 3), a second quarter wave plate 125b, a second mirror Through the 129, the second quarter wave plate 125b, and the third beam splitter 127, it may enter the observer's eye E.

Here, the spatial light modulator 130, the first lens 122a, the first beam splitter 121, the spatial filter 123, the second lens 122b, the second beam splitter 124, the first 1/4 The wave plate 125a and the first mirror 126 may be arranged in a line on the same layer. The light source 110 is disposed above the first beam splitter 121, and the third lens 127 is disposed below the second beam splitter 124. The third beam splitter 128, the second quarter wave plate 125b, and the second mirror 129 may be arranged in a row on the same layer under the third lens 127. In particular, the third beam splitter 128, the second quarter wave plate 125b, and the second mirror 129 may be disposed on the same layer as the observer's eye E. Further, the spatial light modulator 130, the first lens 122a, the first beam splitter 121, the spatial filter 123, the second lens 122b, the second beam splitter 124, the first 1/4 The direction in which the wave plate 125a and the first mirror 126 are arranged and the direction in which the third beam splitter 128, the second quarter wave plate 125b, and the second mirror 129 are arranged are Orthogonal. For example, in FIG. 1, light from the spatial light modulator 130 to the first mirror 126 travels in the y direction, and the light between the third beam splitter 128 and the second mirror 129 is in the x direction. Follow along.

Since the multi-image display apparatus 100 according to the above-described embodiment provides a holographic image having a three-dimensional effect together with an actual external view, a more realistic augmented reality experience may be provided. In addition, the multi-image display apparatus 100 according to the above-described embodiment can increase the length of the optical path within a narrow space by using the first to third beam splitters 121, 124, and 128, thereby reducing a small form factor. Because it has, it can be downsized. Accordingly, the volume and weight of the multi-image display apparatus 100 can be reduced, thereby improving user convenience. In addition, the multi-image display apparatus 100 according to the above-described embodiment may realize a relatively wide viewing angle of about 60 degrees.

For example, FIGS. 5 and 6 schematically illustrate a principle of adjusting the depth of a holographic image visible to an observer in the multi-image display apparatus 100 illustrated in FIG. 1. In FIG. 5, f denotes a focus of the second mirror 129. When parallel light is incident on the second mirror 129, the light reflected from the second mirror 129 is collected at the focal point f. However, in reality, since the light emitted by the third lens 127, which is a concave lens, enters the second mirror 129, the observer's eye E located farther than the focus f from the second mirror 129 ), light is collected. On the other hand, the second mirror 129 and the focus f by adjusting the refractive power of optical components such as the first lens 122a, the second lens 122b, the first mirror 126, and the third lens 127 A real image can be formed between. Then, in the observer's eye E, an enlarged virtual image formed at a distance D from the observer is seen. Accordingly, the multi-image display apparatus 100 can realize a relatively wide viewing angle.

The depth of the holographic image to be reproduced, that is, the distance D, can be adjusted by the position of a real image formed around the spatial light modulator 130. Referring to FIG. 6, a holographic data signal provided to the spatial light modulator 130 from an image processing apparatus (not shown) includes depth information of a holographic image to be reproduced. The position of the holographic plane of the image formed around the spatial light modulator 130 varies according to the depth information. Then, the position of the real image relayed on the optical path between the second mirror 129 and its focal point f from the holographic plane is changed by the optical system 120, and as a result, the distance that the enlarged virtual image is visible to the observer. Will change.

For example, if the position of the holographic plane coincides with the position of the spatial light modulator 130 as indicated by'A', the position of the holographic plane may be defined as 0 (zero). And, if the holographic plane is located in the direction in which light travels from the reflective surface of the spatial light modulator 130 as indicated by'B', the position value of the holographic plane can be defined as having a positive (+) sign. I can. In addition, if the holographic plane is located in a direction opposite to the direction in which light travels from the reflective surface of the spatial light modulator 130 as indicated by'C', the position value of the holographic plane has a negative (-) sign. Can be defined.

7 is a graph exemplarily showing a relationship between a position change of an image formed around the spatial light modulator 130 and a depth of a holographic image visible to an observer. Referring to FIG. 7, as the position value of the holographic plane increases in the positive (+) direction, that is, the holographic plane follows the direction in which light travels from the reflective surface of the spatial light modulator 130. 130), the virtual image of the reproduced holographic image becomes closer to the viewer (ie, the distance D becomes smaller). In addition, as the position value of the holographic plane increases in the negative (-) direction, that is, the holographic plane moves from the reflective surface of the spatial light modulator 130 to the direction opposite to the direction in which light travels. ), the virtual image of the reproduced holographic image appears farther to the observer (ie, the distance D increases).

8 is a block diagram schematically showing a configuration of a multi-image display apparatus 200 according to another exemplary embodiment. Referring to FIG. 8, the multi-image display apparatus 200 includes a left-eye light source 110L, a left-eye optical system 120L, a left-eye spatial light modulator 130L, a right-eye light source 110R, and a right-eye optical system 120R. , And a spatial light modulator 130R for the right eye. The configurations of the left-eye optical system 120L and the right-eye optical system 120R may be the same as those of the optical system 120 described in FIGS. 1 to 4. However, the optical components in the left-eye optical system 120L may be arranged symmetrically in the opposite direction to the optical components in the right-eye optical system 120R.

In addition, the left-eye light source 110L and the right-eye light source 110R may have the same configuration as the light source 110 described in FIGS. 1 to 4, and the left-eye spatial light modulator 130L and the right-eye spatial light modulator ( 130R) may be the same as the configuration of the spatial light modulator 130 described in FIGS. 1 to 4. The left-eye spatial light modulator 130L and the right-eye spatial light modulator 130R may reproduce holographic images having different viewpoints under the control of an image processing apparatus (not shown). For example, the left-eye spatial light modulator 130L reproduces a holographic image having the viewer's left eye view, and the right-eye spatial light modulator 130R may reproduce a holographic image having the observer's right eye view. The multi-image display apparatus 200 may provide a virtual holographic image and an image including an actual external view to both eyes of the observer.

The configuration of the optical system 120 described in FIGS. 1 to 4 may be variously modified as necessary. For example, in the optical system 120 described in FIGS. 1 to 4, the order of some optical elements may be changed as necessary. In addition, in the light path between the light source 110 and the observer's eye (E), polarization characteristics of polarization-dependent parts are differently selected, or additional polarization-selective parts are arranged to select the polarization state of light different from that described in FIGS. May be. In addition, a mirror may be additionally disposed on the optical path between the light source 110 and the observer's eye E to further bend the optical path.

9 exemplarily shows an arrangement of some of the components of a multi-image display device according to another embodiment. 9 is a diagram illustrating a multi-image display device viewed from top to bottom, and for convenience, some configurations are shown in a cross-sectional shape. In the embodiment illustrated in FIG. 4 described above, the light source 110 is disposed on the upper surface of the first beam splitter 121, but the position of the light source 110 is not limited thereto. As shown in FIG. 9, the light source 110 may be disposed on one side of the first beam splitter 121. In this case, the first beam splitter 121 shown in FIG. 9 is disposed to be rotated 90 degrees with the optical axis as a rotation axis compared to the first beam splitter 121 shown in FIG. 4. Then, the first beam splitter 121 may reflect light of the second linearly polarized component incident to the side in the direction of the spatial light modulator 130. In addition, the first beam splitter 121 may transmit light of the first linearly polarized component reflected by the spatial light modulator 130.

In the embodiment shown in FIG. 9, the optical configuration after the second beam splitter 124 may be the same as the embodiment shown in FIG. 4. The second beam splitter 124 reflects light having a first linearly polarized component and transmits light having a second linearly polarized component. Accordingly, a half-wave plate 125c may be further disposed in front of the second beam splitter 124. In FIG. 9, it is shown that the half-wave plate 125c is disposed between the second lens 122b and the second beam splitter 124, but the light between the first beam splitter 121 and the second beam splitter 124 The half-wave plate 125c may be disposed anywhere on the path. The light of the first linearly polarized component that has passed through the first beam splitter 121 is converted into light of the second linearly polarized component while passing through the half-wave plate 125c. Thereafter, the light of the second linearly polarized component passes through the second beam splitter 124 and enters the first mirror 126.

Instead, the light source 110 may be disposed on the lower surface of the first beam splitter 121. In this case, the light source 110 and the third lens 127 (see FIG. 2) may be disposed on the same side with respect to the optical axis of the optical system. In addition, the first beam splitter 121 is rotated 180 degrees with an optical axis as a rotation axis compared to the first beam splitter 110 shown in FIG. 4, and the light of the first linearly polarized component incident on the lower surface is spaced. It can reflect in the direction of the optical modulator 130.

10 is a cross-sectional view illustrating an arrangement of some parts among parts of a multi-image display device according to another exemplary embodiment. FIG. 10 illustrates a multi-image display device in the same direction as that illustrated in FIG. 3. In the embodiment of FIG. 3, it has been described that the third beam splitter 128 reflects light of the first linearly polarized component and transmits light of the second linearly polarized component. However, it is not necessarily limited thereto. In the embodiment of FIG. 10, the third beam splitter 128a may be configured to transmit light of the first linearly polarized component and reflect light of the second linearly polarized component. In the embodiment illustrated in FIG. 10, the rest of the optical system except for the third beam splitter 128a may be the same as the optical systems illustrated in FIGS. 2 and 3. In this case, the second quarter wave plate 125b and the second mirror 129 may be disposed under the third beam splitter 128a.

Then, the light of the first linearly polarized component that is reflected by the second beam splitter 124 and has passed through the third lens 127 passes through the third beam splitter 128a and the second quarter wave plate 125b. 2 It enters the mirror 129. At this time, the light has a first circularly polarized light component. Light having the first circularly polarized light component is converted into a second circularly polarized light component while being reflected in the opposite direction by the second mirror 129. Further, the light has a second linearly polarized light component while passing through the second quarter wave plate 125b again. The light having the second linearly polarized component is reflected by the third beam splitter 128a and is incident on the observer's eye E.

Meanwhile, the light having the first linearly polarized light component among the light containing the external foreground may pass through the third beam splitter 128a and enter the observer's eye E. Accordingly, the holographic image IMG1 has a second linearly polarized component and the external image IMG2 has a first linearly polarized component. On the other hand, in the embodiment shown in FIG. 3, both the holographic image IMG1 and the external image IMG2 have a second linearly polarized light component.

Until now, it has been described that the first mirror 126 and the second mirror 129 are concave mirrors having positive (+) refractive power. However, either or both of the first mirror 126 and the second mirror 129 may be a flat mirror. For example, FIG. 11 is a cross-sectional view illustrating an arrangement of some components among components of a multi-image display device according to another exemplary embodiment. FIG. 11 illustrates a multi-image display device in the same direction as that illustrated in FIG. 2. Referring to FIG. 11, the first mirror 126 of the multi-image display device may be a flat mirror. When the first mirror 126 is a flat mirror, the curvature of the first to third lenses 122a, 122b, 127 and the second mirror 129 so that the holographic image can be accurately provided to the observer's eye E Can be changed.

12 is a cross-sectional view illustrating an arrangement of some parts among parts of a multi-image display device according to another exemplary embodiment. 12 illustrates a multi-image display device in the same direction as that illustrated in FIG. 3. Referring to FIG. 12, the second mirror 129 of the multi-image display device may be a flat mirror. When the second mirror 129 is a flat mirror, the curvature of the first to third lenses 122a, 122b, 127 and the first mirror 126 so that a holographic image can be accurately provided to the observer's eye E Can be changed. Instead, both the first mirror 126 and the second mirror 129 may be flat mirrors. In this case, by adjusting the curvature of the first to third lenses 122a, 122b, 127, a holographic image may be accurately provided to the observer's eye E.

13 is a cross-sectional view illustrating an arrangement of some parts among parts of a multi-image display device according to another exemplary embodiment. Referring to FIG. 13, the multi-image display device may include a light source 110 that provides parallel light to the first beam splitter 121. For example, the light source 110 includes a beam combiner 111 disposed opposite to the first beam splitter 121, and a first light emitting element 112G disposed opposite to the first surface 111a of the beam combiner 111 ), a first collimating lens 113G disposed between the beam combiner 111 and the first light emitting device 112G, and a second light emitting device disposed opposite to the second surface 112b of the beam combiner 111 ( 112R), a second collimating lens 113R disposed between the beam combiner 111 and the second light emitting device 112R, a third light emitting device disposed opposite to the third surface 111c of the beam combiner 111 (112B), and a third collimating lens (113B) disposed between the beam combiner 111 and the third light emitting element (112B). The beam combiner 111 may be disposed such that its fourth surface 111d faces the first beam splitter 121. For example, the beam combiner 111 may be an X-cube.

In the configuration of the light source 110, the light emitted from the first light emitting element 112G becomes parallel light by the first collimating lens 113G, and is reflected by the beam combiner 111 to be a first beam splitter ( 121). In addition, light emitted from the second light emitting element 112R becomes parallel light by the second collimating lens 113R, passes through the beam combiner 111 and enters the first beam splitter 121. In addition, light emitted from the third light-emitting element 112B becomes parallel light by the third collimating lens 113B, is reflected by the beam combiner 111, and may enter the first beam splitter 121. .

Until now, it has been described that the spatial light modulator 130 is a reflective spatial light modulator that modulates while reflecting incident light. However, it is also possible to use a transmission type spatial light modulator that modulates while transmitting incident light. For example, FIG. 14 is a cross-sectional view illustrating an arrangement of some parts among parts of a multi-image display device according to another embodiment, and illustrating a multi-image display device in the same direction as that illustrated in FIG. 2. will be.

Referring to FIG. 14, the multi-image display device includes a surface light source 110a providing parallel light instead of the light source 110, the first beam splitter 121, and the reflective spatial light modulator 130 shown in FIG. And a transmissive spatial light modulator 130a. Accordingly, the surface light source 110a, the transmissive spatial light modulator 130a, and the first lens 122a may be sequentially disposed along the traveling direction of light. The configuration after the first lens 122a may be the same as the configuration described in FIGS. 2 and 3. In this case, the second beam splitter 124 may be configured to transmit light coming from the transmissive spatial light modulator 130a. In addition, the optical system is a first optical path along the first mirror 126 from the surface light source 110a, the second beam splitter 124 and the third beam splitter 128 (refer to FIG. 3) along a vertical direction. It may include 2 optical paths, and a third optical path along the second mirror 129 (refer to FIG. 3) and the observer.

Meanwhile, the multi-image display device may include a point light source and a collimating lens instead of the surface light source 110a. The transmissive spatial light modulator 130a may use, for example, a semiconductor modulator based on a compound semiconductor such as GaAs, or a liquid crystal device (LCD). When the transmission-type spatial light modulator 130a is used, the first beam splitter 121 may be omitted, and thus the configuration of the optical system may be simplified.

15 is a perspective view schematically illustrating a configuration of a multi-image display device according to another exemplary embodiment. Referring to FIG. 15, the multi-image display apparatus 300 may include a light source 310, an optical system 320, and a spatial light modulator 330. The light source 310 is the same as the light source 110 of the multi-image display device 100 shown in FIG. 1, and the spatial light modulator 330 is a spatial light modulator ( 130).

The optical system 320 includes a first lens 322a, a first beam splitter 321, a spatial filter 323, a second lens 322b, a half-wave plate 326 that are sequentially arranged along the +y direction, and a first A mirror 324 may be included. In addition, the optical system 320 may further include a third lens 327 and a second beam splitter 328 sequentially disposed under the first mirror 324 in the -z direction. In addition, the optical system 320 may further include a quarter wave plate 325 and a second mirror 329 which are sequentially disposed along the -x direction facing the second beam splitter 328. Therefore, when compared with the optical system 120 of the multi-image display apparatus 100 shown in FIG. 1, the optical system 320 of the multi-image display apparatus 300 uses a mirror 324 instead of the second beam splitter 124. It includes, and does not include the first quarter-wave plate (125a) and the first mirror 126, further includes a half-wave plate (132).

16 is a cross-sectional view taken along one direction illustrating an example of an arrangement of some of the components of the multi-image display apparatus 300 illustrated in FIG. 15. For example, FIG. 16 is a plane including a z-axis and a y-axis in order to specifically show the components from the spatial light modulator 330 to the third lens 327 arranged along the +y direction, and the optical system 320 Is a cross-sectional view cut.

Referring to FIG. 16, the light source 310 is disposed to face the first surface 321a of the first beam splitter 321. Accordingly, the light emitted from the light source 310 is incident on the first surface 321a of the first beam splitter 321. The first beam splitter 321 is a polarization beam splitter that reflects light having a first linearly polarized component and transmits light having a second linearly polarized component orthogonal to the first linearly polarized component. Then, among the light emitted from the light source 310, light having a first linearly polarized component is reflected by the first beam splitter 321, and light having a second linearly polarized component may pass through the first beam splitter 321. .

The spatial light modulator 330 is disposed to face the second surface 321b of the first beam splitter 321. The light having the first linearly polarized light component reflected by the first beam splitter 321 is emitted through the second surface 321b of the first beam splitter 321 and then incident on the spatial light modulator 330. The first lens 322a converts light coming from the first beam splitter 321 into parallel light having a constant beam mirror. The spatial light modulator 330 modulates and reflects incident light, and the modulated light interferes with each other to form a holographic image. In addition, when the light is modulated by the spatial light modulator 330, the light is rotated by 90 degrees, so that the light has a second linearly polarized component. The light containing the holographic image is again incident on the second surface 321b of the first beam splitter 321. At this time, the light is focused while passing through the first lens 322a. Light having the second linearly polarized light component passes through the first beam splitter 321 and is emitted to the third surface 321c of the first beam splitter 321 facing the second surface 321b.

The light transmitted through the first beam splitter 321 passes through the spatial filter 323, the second lens 322b, and the half-wave plate 326 and enters the first mirror 324. In FIG. 16, the spatial filter 123, the second lens 122b, and the half-wave plate 326 are arranged in the order of the light traveling direction, but the present invention is not limited thereto. For example, the spatial filter 123 and the second lens 122b may be disposed in an optical path between the first beam splitter 321 and the first mirror 324 in any order. In addition, the half-wave plate 326 may be disposed anywhere in the optical path between the first beam splitter 321 and the second beam splitter 328.

Light having the second linearly polarized component has a first linearly polarized component while its phase is changed by 180 degrees by the half-wave plate 326. Light having the first linearly polarized component is reflected by the first mirror 324 and is incident on the third lens 327 under the first mirror 324. Accordingly, the light traveling direction is bent by about 90 degrees by the first mirror 324. To this end, the first mirror 324 may be disposed to be inclined to change the traveling direction of light by approximately 90 degrees. Then, the light reflected by the first mirror 324 proceeds in the -z direction. In addition, although the first mirror 324 is illustrated as a simple flat mirror in FIG. 16, the first mirror 324 may be a concave mirror having a concave reflective surface so as to enlarge an image.

The light reflected by the first mirror 324 passes through the third lens 327 and enters the second beam splitter 328. Light incident on the second beam splitter 328 has a first linearly polarized component. The configuration and operation of the second beam splitter 328, the quarter wave plate 325, and the second mirror 329 are described in FIG. 3 as the third beam splitter 128 and the second quarter wave plate 125b. And the configuration and operation of the second mirror 129. For example, the second beam splitter 328 may be a polarization beam splitter that reflects light having a first linearly polarized component and transmits light having a second linearly polarized component orthogonal to the first linearly polarized component. Alternatively, the configuration and operation of the second beam splitter 328, the quarter wave plate 325, and the second mirror 329 are described in FIG. 10 as the third beam splitter 128 and the second quarter wave plate ( 125b) and the configuration and operation of the second mirror 129 may be the same. In this case, the second beam splitter 328 may be configured to transmit light of the first linearly polarized component and reflect light of the second linearly polarized component. Accordingly, the second beam splitter 328 transmits the light reflected from the first mirror 324 and reflects the light reflected from the second mirror 129.

FIG. 17 is a cross-sectional view taken along one direction to show another example of an arrangement of some of the components of the multi-image display device 300 illustrated in FIG. 15. Compared with the example shown in FIG. 16, in the example shown in FIG. 17, the half-wave plate 326 is omitted. In this case, the light reflected by the first mirror 324 and incident on the second beam splitter 328 has a second linearly polarized light component.

FIG. 18 is a cross-sectional view taken along a different direction to show an arrangement of some other parts among the parts of the multi-image display device 300 illustrated in FIG. 15. For example, FIG. 18 is a cross-sectional view of the optical system 320 cut in a plane including the z-axis and the x-axis in FIG. 15 in order to show the path of light from the first mirror 324 to the observer's eye in detail. . Since the cross-sectional view of FIG. 18 is rotated by 90 degrees with respect to the cross-sectional view of FIG. 17, the linearly polarized light component in FIG. 18 is displayed opposite to that of FIG. 17. For example, in FIG. 17, the first linearly polarized component is indicated by'⊙' and the second linearly polarized component is indicated by'↕', but in FIG. 18, the first linearly polarized component is indicated by'↕' and the second linearly polarized component is indicated by ' It is displayed as'⊙'.

Referring to FIG. 18, the second beam splitter 328 is a polarization beam splitter that reflects light having a second linearly polarized component and transmits light having a first linearly polarized component. Accordingly, the light of the second linearly polarized light component reflected by the first mirror 324 and incident on the second beam splitter 328 is reflected by the second beam splitter 328. At this time, the path of light is bent by about 90 degrees so that the light proceeds in the -x direction. Light reflected by the second beam splitter 328 passes through the 1/4 wave plate 325 and enters the second mirror 329. Light incident on the second mirror 329 has a second circularly polarized light component by the 1/4 wave plate 325.

Light having the second circularly polarized light component is reflected by the second mirror 329 in the opposite direction, that is, 180 degrees with respect to the incident direction. Thus, the light reflected by the two mirrors 329 travels in the +x direction. In this case, the polarization component of the light reflected by the second mirror 329 is converted into the first circular polarization component. Then, the light has a first linearly polarized component while passing through the quarter wave plate 325 again. Thereafter, the light having the first linearly polarized component passes through the second beam splitter 328 and enters the observer's eye E. The second mirror 329 may be a concave mirror having a concave reflective surface to magnify an image, or may be a simple flat mirror.

Instead, the second beam splitter 328 may be a polarization beam splitter that reflects light having a first linearly polarized component and transmits light having a second linearly polarized component. In this case, the configuration and operation of the second beam splitter 328, the quarter wave plate 325, and the second mirror 329 are the third beam splitter 128 and the second quarter wave plate described in FIG. The configuration and operation of 125b and the second mirror 129 are the same, and only the polarization direction can be reversed.

19 to 21 illustrate various electronic devices employing the multi-image display apparatus 100 according to the above-described embodiments. As shown in FIGS. 19 to 21, the multi-image display apparatus 100 may constitute a wearable device. In other words, the multi-image display device 100 may be applied to a wearable device. For example, the multi-image display apparatus 100 may be applied to a head mounted display (HMD). In addition, the multi-image display apparatus 100 may be applied to a glasses-type display, a goggle-type display, or the like. The wearable electronic devices shown in FIGS. 19 to 21 may be operated in conjunction with a smart phone. Such a multi-image display device 100 is a head-mounted, glasses-type, or goggles-type virtual reality (VR) display device, augmented reality (AR) that can provide virtual reality or provide both a virtual image and an external real image. ) It may be a display device, or a mixed reality (MR) display device.

In addition, the multi-image display device 100 may be provided in a smartphone, and such a smartphone itself may be used as a multi-image display device. In other words, the multi-image display device 100 may be applied to a small electronic device (mobile electronic device) other than the wearable device as shown in FIGS. 19 to 21. In addition, the application field of the multi-image display apparatus 100 may be variously changed. For example, the multi-image display apparatus 100 can be applied not only to realizing virtual reality (VR), augmented reality (AR), or mixed reality (MR), but also to other fields. For example, it can also be applied to a small television or a small monitor that a user can wear.

The multi-image display device providing the above-described holographic image has been described with reference to the embodiment shown in the drawings, but this is only an example, and various modifications and equivalent other implementations therefrom are those of ordinary skill in the art. You will understand that an example is possible. Therefore, the disclosed embodiments should be considered from an illustrative point of view rather than a limiting point of view. The scope of the rights is indicated in the claims rather than the above description, and all differences within the scope of the same should be interpreted as being included in the scope of the rights.

100, 200, 300.....Multi-image display device
110, 110a, 310.....
111.....beam combiner
112R, 112G, 112B.....light emitting element
113R, 113G, 113B.....collimating lens
120, 320.....optical system
121, 124, 128, 128a, 321, 328.....beam splitter
122a, 122b, 127, 332a, 322b, 327.....lens
123, 323..... spatial filter
125a, 125b, 325..... 1/4 wave plate
125c, 326.....half-wave plate
126, 129, 324, 329.....mirror
130, 130a, 330..... spatial light modulator

Claims (30)

A light source that emits light;
A spatial light modulator that modulates the light emitted from the light source to reproduce a first image; And
Including; an optical system for transmitting the first image to the observer,
The propagation path of the reproduced first image includes a first optical path along a first direction, a second optical path along a second direction orthogonal to the first direction, and a third direction orthogonal to the first and second directions. The optical system is configured to include a third optical path according to,
A multi-image display device in which the optical system is configured such that the first image and a second image coming from a path different from the first image are provided to an observer along the third optical path. The method of claim 1,
The first image is a virtual holographic image, and the second image is an external image containing an actual external view. The method of claim 1,
The spatial light modulator is a reflective spatial light modulator that reflects and modulates light emitted from the light source. The method of claim 3,
The optical system is:
A first beam splitter that reflects the light emitted from the light source to the spatial light modulator and transmits the light reflected from the spatial light modulator;
A second beam splitter for transmitting light coming from the first beam splitter;
A first mirror disposed to reflect light transmitted through the second beam splitter to the second beam splitter;
A third beam splitter disposed under the second beam splitter; And
And a second mirror disposed to reflect light from the third beam splitter to the third beam splitter. The method of claim 4,
The second beam splitter is configured to reflect light reflected from the first mirror to the third beam splitter. The method of claim 4,
The first beam splitter, the second beam splitter, and the third beam splitter are semi-transmissive mirrors that reflect half of the incident light and transmit the other half. The method of claim 4,
The first beam splitter, the second beam splitter, and the third beam splitter reflect light having a first linearly polarized component and transmit light having a second linearly polarized component orthogonal to the first linearly polarized component. Display device. The method of claim 7,
The optical system further includes a first quarter wave plate disposed between the second beam splitter and the first mirror, and a second quarter wave plate disposed between the third beam splitter and the second mirror. A multi-image display device comprising. The method of claim 7,
The third beam splitter is configured to reflect light from the second beam splitter and to transmit light reflected from the second mirror. The method of claim 9,
The second mirror includes a first surface opposite to the third beam splitter and a second surface opposite to the first surface, and the second mirror reflects a first image incident on the first surface and the A multi-image display device configured to transmit a second image incident on the second surface. The method of claim 4,
The first beam splitter and the second beam splitter are polarizing beam splitters that reflect light having a first linearly polarized component and transmit light having a second linearly polarized component orthogonal to the first linearly polarized component, and the third beam splitter is a A multi-image display device comprising a polarization beam splitter that transmits light having a first linearly polarized component and reflects light having a second linearly polarized component that is orthogonal to the first linearly polarized component. The method of claim 11,
The third beam splitter transmits light from the second beam splitter and reflects the light reflected from the second mirror. The method of claim 4,
The optical system is:
A first lens disposed between the spatial light modulator and the first beam splitter;
A second lens disposed between the first beam splitter and the second beam splitter; And
A multi-image display apparatus further comprising a third lens disposed between the second beam splitter and the third beam splitter. The method of claim 13,
The first lens and the second lens are convex lenses, and the third lens is a concave lens. The method of claim 13,
The optical system further comprises a spatial filter disposed between the first beam splitter and the second beam splitter near a focal point of the first lens. The method of claim 4,
The first optical path is formed between the spatial light modulator and the first mirror, the second optical path is formed between the second beam splitter and the third beam splitter, and between the second mirror and the observer A multi-image display device in which the third optical path is formed. The method of claim 16,
The first optical path and the third optical path have different positions in a height direction, and the second optical path is vertically formed between the first optical path and the third optical path. The method of claim 4,
At least one of the first mirror and the second mirror is a concave mirror. The method of claim 4,
The second mirror is a concave mirror,
The optical system is a multi-image display device configured to form a real image of the first image between the focus of the second mirror and the second mirror. The method of claim 4,
At least one of the first mirror and the second mirror is a concave mirror. The method of claim 3,
The optical system is:
A first beam splitter that reflects the light emitted from the light source to the spatial light modulator and transmits the light reflected from the spatial light modulator;
A first mirror reflecting light from the first beam splitter;
A second beam splitter disposed under the first mirror; And
And a second mirror disposed to reflect light from the second beam splitter to the second beam splitter. The method of claim 21,
The second beam splitter is configured to reflect light from the first mirror and to transmit light reflected from the second mirror. The method of claim 22,
The first beam splitter and the second beam splitter are polarizing beam splitters that reflect light having a first linearly polarized component and transmit light having a second linearly polarized component orthogonal to the first linearly polarized component,
The optical system further comprises a half-wave plate disposed between the first beam splitter and the second beam splitter, and a quarter wave plate disposed between the second beam splitter and the second mirror. . The method of claim 22,
The first beam splitter is a polarization beam splitter that reflects light having a first linearly polarized component and transmits light having a second linearly polarized component orthogonal to the first linearly polarized component, and the second beamsplitter has a first linearly polarized component. It is a polarizing beam splitter that transmits light and reflects light having a second linearly polarized component,
The optical system further comprises a quarter wave plate disposed between the second beam splitter and the second mirror. The method of claim 21,
The second beam splitter is configured to transmit light coming from the first mirror and reflect light reflected from the second mirror. The method of claim 1,
The spatial light modulator is a transmission type spatial light modulator that transmits and modulates light emitted from the light source. The method of claim 26,
The optical system is:
A second beam splitter for transmitting light coming from the spatial light modulator;
A first mirror disposed to reflect light transmitted through the second beam splitter to the second beam splitter;
A third beam splitter disposed under the second beam splitter; And
And a second mirror disposed to reflect light from the third beam splitter to the third beam splitter. The method of claim 27,
The optical system is:
A first lens and a second lens disposed between the spatial light modulator and the second beam splitter;
A spatial filter disposed between the first lens and the second lens; And
A multi-image display apparatus further comprising a third lens disposed between the second beam splitter and the third beam splitter. The method of claim 28,
The first lens and the second lens are convex lenses, and the third lens is a concave lens. The method of claim 27,
The first optical path is formed between the light source and the first mirror, the second optical path is formed between the second beam splitter and the third beam splitter, and the second optical path is formed between the second mirror and the observer. 3 A multi-image display device in which an optical path is formed.

Images