KR20170049358A - See-through Type holographic display apparatus - Google Patents

Abstract

A perspective type holographic display device is disclosed. The disclosed perspective type holographic display device includes a relay optical system to enlarge or reduce a holographic image reproduced in a spatial light modulator and transmit the holographic image to a display device including a noise elimination filter to remove noise from diffracted light of a hologram image transmitted through a relay optical system And a light path changer for changing at least one of an optical path of the diffracted light of the holographic image transmitted from the relay optical system and an optical path of the external light so that the hologram image and the outside can be simultaneously or selectively viewed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a holographic display apparatus,

The present disclosure relates to a holographic display device, and more particularly, to a perspective holographic display device capable of simultaneously or selectively viewing a hologram image and an outside.

In recent years, 3D movies have been released, and many technologies related to 3D display have been studied. For example, researches on a device capable of realizing high-quality hologram in real time using a spatial light modulator (SLM) have been actively conducted.

Recently, related research and related products have been introduced to a head mounted display (HMD) for realizing a virtual reality (VR). In addition, major venture companies are also frequently acquiring existing venture companies with VR technology. However, existing VR HMDs are based on stereoscopy technology and cause visual fatigue due to focus and accommodation-vergence conflict. In addition, existing VR HMDs cause many problems when combined with technologies such as spatial interaction.

The present disclosure is intended to provide a display device capable of realizing a hologram stereoscopic image in a see-through manner.

The present disclosure seeks to provide a personal perspective type three-dimensional stereoscopic display HMD.

A perspective type holographic display device according to one aspect includes: a light source for providing light; A spatial light modulator for diffracting the light to reproduce a hologram image; A relay optical system for enlarging or reducing the holographic image reproduced by the spatial light modulator and transmitting the holographic image; A noise removing filter for removing noise from the diffracted light of the hologram image transmitted through the relay optical system; And an optical path changer for changing at least one of an optical path of the diffracted light of the holographic image transmitted from the relay optical system and an optical path of the external light and transmitting the diffracted light and the external light to the same area.

The perspective type holographic display device according to one aspect may further include a collimator for converting the light provided from the light source into a parallel light flux.

The spatial light modulator may be an amplitude modulated spatial light modulator or a phase modulated spatial light modulator.

The relay optical system may include a first optical element into which a hologram image modulated by the spatial light modulator is incident and a second optical element with a second focus on the incident surface side near the first focus point on the exit surface of the first optical element have. The first optical element may have a first focal length, and the second optical element may have a second focal length different from the first focal distance. The noise elimination filter may be arranged near the first focal point on the emission surface side of the first optical element. The noise removing filter may be a diaphragm.

The perspective type holographic display device according to one aspect may further include a field optical element for focusing the holographic image transmitted from the relay optical system.

The field optical element may be located in the vicinity of the image plane on which the hologram image transmitted from the relay optical system is imaged.

Or the field optical element may be arranged such that an image plane on which the hologram image transmitted from the relay optical system is imaged is positioned between an incident surface side focus position of the field optical element and an incident surface of the field optical element. In other words, the field optical element can be arranged so that the image plane on which the hologram image transmitted from the relay optical system is formed is redefined as a fixed image.

The field optical element may be disposed adjacent to the optical path changer. The distance between the relay optical system and the field optical element can be changed to adjust the size of the holographic image transmitted from the relay optical system.

The optical path changer includes a first surface on which diffracted light of a hologram image transmitted from the relay optical system is incident, a second surface on which external light is incident, and a third surface opposite to the second surface, And a beam splitter which reflects at least a part of the diffracted light of the hologram image incident on the first surface to the third surface and transmits at least a part of external light incident on the second surface to the third surface, The field optical element may be a field lens disposed adjacent to the first side of the optical path changer.

The optical path changer includes a first surface on which diffracted light of a hologram image transmitted from the relay optical system is incident, a second surface on which external light is incident, a third surface opposite to the second surface, At least a part of the diffracted light of the hologram image incident on the first surface is transmitted through the fourth surface and the diffracted light of the hologram image re-incident on the second surface is incident on the fourth surface, And a beam splitting film that reflects at least a portion of the external light incident on the second surface to the third surface, and the field optical element is arranged on the fourth surface of the optical path changer Or may be a concave reflector disposed adjacently.

The optical path changer may be a half mirror, and the field optical element may be a field lens positioned between the relay optical system and the optical path changer and disposed adjacent to the optical path changer.

The optical path changer includes a first surface on which diffracted light of a hologram image transmitted from the relay optical system is incident, a second surface on which external light is incident, and a third surface opposite to the second surface, And a beam splitter which reflects at least a part of the diffracted light of the hologram image incident on the first surface to the third surface and transmits at least a part of external light incident on the second surface to the third surface, The beam splitting film has a concave curved shape with respect to the first surface, and the hologram image transmitted from the relay optical system can be reflected while being reflected on the third surface. Here, the beam separation film functions as a field optical element.

The beam separating film may be a polarization selective reflective film.

The light path changer may be disposed such that the beam separating film is positioned in the vicinity of an image plane on which the hologram image transmitted from the relay optical system is imaged. Or the optical path changer may be arranged such that an image plane on which the holographic image transmitted from the relay optical system is formed is positioned inside the focus of the beam separating film. In other words, the optical path changer may be arranged so that the image plane on which the hologram image transmitted from the relay optical system is formed is redefined as a fixed virtual image.

A light beam-selective optical element for focusing diffracted light and transmitting external light (at least some polarization components) as it is can be further provided. Wherein the light beam-selective optical element is a cemented lens of an isotropic lens and an anisotropic lens, the refractive power of the cemented lens has a positive value with respect to the diffracted light, and the total refractive power of the cemented lens with respect to external light has zero . Alternatively, the light beam-selective optical element may include first and second transparent substrate layers opposed to each other, and liquid crystal interposed between the first and second transparent substrate layers, and at least one of the first and second transparent substrate layers And the liquid crystal may be controlled by the electrodes provided in the liquid crystal lens.

The optical path changer may be an active reflector for adjusting the amount of light transmitted through the external light. The active reflector may include any one of a liquid crystal filter and an electrochromic device for adjusting the amount of light transmitted through the external light.

The light path transducer may be disposed near the pupil of the viewer.

The perspective type holographic display device may be installed in a head mounted housing which is worn on at least one of the left and right eyes of the viewer's head.

A head-mounted display device according to another aspect is an apparatus for displaying a hologram image, comprising: a left-eye perspective holographic display device; A right eye perspective holographic display device; And a frame connecting the left eye perspective holographic display device and the right eye perspective holographic display device, wherein each of the left eye perspective holographic display device and the right eye perspective holographic display device includes a light source for providing light, A spatial light modulator for diffracting light to reproduce a hologram image; a relay optical system for enlarging or reducing the hologram image reproduced by the spatial light modulator and transmitting the hologram image; and a spatial light modulator for removing noise from the diffracted light of the holographic image transmitted through the relay optical system And a light path changer for changing at least one of an optical path of the diffracted light of the hologram image transmitted from the relay optical system and an optical path of the external light and transmitting the diffracted light and the external light to the same area .

When the head-mounted display device is worn on the user's head, the optical path changer of the left-eye perspective type holographic display device is located adjacent to the left eye of the user, and the optical path changer of the right- As shown in FIG.

The distance between the optical path changer of the left eye perspective type holographic display device and the optical path changer of the right eye perspective type holographic display device can be adjusted.

The perspective type holographic display device according to the disclosed embodiments can view the hologram image while viewing the hologram image.

The perspective type holographic display device according to the disclosed embodiments can adjust the size of the angle of view.

The perspective type holographic display device according to the disclosed embodiments is applicable to a personal perspective type head mounted display device.

The perspective type holographic display device according to the disclosed embodiments can implement an optical system for implementing a hologram in an amplitude modulation manner in a head mounted display device.

When the perspective type holographic display device according to the disclosed embodiments is applied to a binocular display device, since the left eye optical system and the right eye optical system are completely separated from each other, either the left eye optical system or the right eye optical system, The distance between the pupils can be adjusted by moving in accordance with the distance between the left pupil and the right pupil of the observer.

1 is a view schematically showing an example in which a perspective holographic display device according to an embodiment is worn by a user.
2 is a view schematically showing an optical system of the perspective type holographic display device of FIG.
3 is a view showing an example of the arrangement of the field lens.
4 is a view showing another example of the arrangement of the field lens.
5 is a view for explaining an operation according to the arrangement of the field lens of FIG.
6 is a view schematically showing an optical system of a perspective type holographic display device according to another embodiment.
7 is a view schematically showing an optical system of a perspective type holographic display device according to still another embodiment.
8 is a view schematically showing an optical system of a perspective type holographic display device according to still another embodiment.
9 is a view schematically showing an optical system of a perspective type holographic display device according to still another embodiment.
10 is a view for explaining the operation of the perspective type holographic display device of FIG.
11 is a view schematically showing an optical system of a perspective type holographic display device according to still another embodiment.
12 is a view schematically showing an optical system of a perspective type holographic display device according to still another embodiment.
13 is a view schematically showing an optical system of a perspective type holographic display device according to still another embodiment.
FIG. 14 is a view showing an example of a light beam-selective optical element employed in the perspective holographic display device of FIG.
Figs. 15A to 15C are views showing other examples of optical beam-selective optical elements employed in the perspective holographic display device of Fig.
16 is a plan view schematically showing an example in which a head mounted display device (perspective holographic display device) according to another embodiment is worn by a user.
Fig. 17 is a view schematically showing an optical system of the head mounted display device of Fig. 16; Fig.

Hereinafter, a perspective type holographic display device will be described in detail with reference to the accompanying drawings. In the following drawings, like reference numerals refer to like elements, and the size of each element in the drawings may be exaggerated for clarity and convenience of explanation.

1 is a view schematically showing an example in which a perspective type holographic display device 100 according to an embodiment is worn by a user (observer) 10, and Fig. 2 is a perspective view of a perspective type holographic display device 100 shown in FIG.

Referring to FIG. 1, the perspective type holographic display device 100 of the present embodiment may be a wearable device worn on the head of the user 10, such as a pair of glasses. For example, the perspective type holographic display device 100 can simultaneously display the holographic image and the outside through either one of the two eyes 11 of the user 10 (illustratively, the left eye 11L as shown in the figure) It can have the form of eye glasses that can be seen. As another example, the perspective type holographic display device 100 may have a shape attached to either one of the glasses (for example, the left eye 11L as shown in the drawing).

The perspective type holographic display device 100 may include an optical system installed in the housing 190 and the housing 190, and a control unit 900 for controlling these optical systems. The control unit 900 may be provided outside the housing 190 or inside the housing 190.

2, the perspective type holographic display device 100 of the present embodiment includes a light source 110 for providing light, a spatial light modulator 120 for generating a hologram image, And a relay optical system 140 that changes at least one of an optical path of the diffracted light of the hologram image transmitted from the relay optical system 140 and an optical path of the external light to transmit the diffracted light of the hologram image And an optical path changer 180 for transmitting external light to the same area. In addition, a noise removing filter 150 for removing noise from the diffracted light of the hologram image transmitted through the relay optical system 140 may be further provided. Further, a field lens 170 for focusing the holographic image transmitted from the relay optical system 140 may be further provided. The control unit 900 may further include a light source unit 110 and a spatial light modulator 120 to generate a hologram image.

The light source unit 110 includes a light source 111. The light source 111 may include a laser diode (LD) to provide the spatial light modulator 120 with light having high coherence. However, since the light provided by the light source 111 can be sufficiently diffracted and modulated by the spatial light modulator 120 if it has spatial coherence above a certain level, Emitting diode (LED) may be used. In addition, the light source 111 may include a light source array of red, green, and blue, and may implement a color hologram image by RGB time division driving as described later. For example, the light source 111 may comprise a plurality of laser diodes or an array of light emitting diodes. Further, any other light source can be used as long as the light source 111 emits light having spatial coherence in addition to a laser diode or a light emitting diode.

The light source unit 110 illuminates the collimated parallel light. For example, the light source unit 110 may further include a collimator lens 112 to collimate the light emitted from the light source 111 into parallel light.

The spatial light modulator 120 may form a hologram pattern on the light-modulating surface in accordance with the hologram data signal provided from the controller 900. The light incident on the spatial light modulator 120 is diffracted light modulated with the hologram wavefront by the hologram pattern. The diffracted light having the image of the hologram wavefront allows the hologram image to be viewed by the diffraction interference in the viewing window (VW) via the relay optical system 140 and the field lens 170 as described later.

 The spatial light modulator 120 can suppress resolution deterioration by using an amplitude spatial light modulator capable of performing only amplitude modulation and suppress image quality deterioration when displaying a 2D image. For example, the spatial light modulator 120 may use a DMD (digital micromirror device), a liquid crystal on silicon (LCoS), or a semiconductor optical modulator. Of course, it is of course possible to use a spatial light modulator that modulates both phase and amplitude as the spatial light modulator 120, or a phase-spatial light modulator that modulates the phase.

Between the light source 111 and the spatial light modulator 120, a light splitter 130 for splitting the incident light and the emitted light may be disposed. Here, the incident light and the emitted light indicate light incident on and emitted from the spatial light modulator 120, respectively. The optical splitter 130 directs the light incident from the light source 111 to the spatial light modulator 120 and reflects the light reflected from the spatial light modulator 120 to the relay optical system 140 beam splitter. As another example, the optical multiplexer 130 may be a half mirror.

The light illuminated by the light source unit 110 may have polarized light. The light source 111 itself may emit polarized light or a polarizing filter may be disposed in the light source unit 110 to polarize the light emitted from the light source 111. [ In this case, the optical component 130 may be a polarization beam splitter. A polarization conversion member such as a quarter wave plate (not shown) is further disposed between the optical multiplexer 130 and the spatial light modulator 120 so that the polarization of the light from the optical multiplexer 130 toward the spatial light modulator 120 The polarization of the light reflected by the spatial light modulator 120 and directed to the optical splitter 130 may be different from each other, and the incident light and the outgoing light may be branched more efficiently.

A reflective member 113 may be provided between the light source 111 and the optical distributor 130. The reflecting member 113 may be a total reflection prism or a simple mirror. The reflecting member 113 may be provided for proper placement of optical members such as the light source 111 within a limited space of the housing 190. [

The relay optical system 140 may be a modified 4f optical system that enlarges or reduces the hologram wavefront generated by the spatial light modulator 120 and transmits the enlarged or reduced hologram wavefront. For example, the relay optical system 140 may include a first relay lens 141 having a first focal length f ₁ and a second relay lens 143 having a second focal length f ₂ . The first relay lens 141 is disposed such that the light modulation surface on which the light of the spatial light modulator 120 is modulated is located at or near the incident side first focal distance f ₁ of the first relay lens 141 . The second relay lens 143 may be disposed so as to be positioned at or near the incident surface side second focal length f _{2 at} the position of the first focal distance f ₁ on the exit surface side of the first relay lens 141 have. The optical arrangement of the relay optical system 140 allows the image of the hologram wavefront generated at the surface of the spatial light modulator 120 to pass through the relay optical system 140 to the second focal distance (f ₂ ) to be imaged in the vicinity thereof. Hereinafter, the image of the hologram wavefront imaged by the relay optical system 140 will be referred to as 'imaged SLM' (172 in FIG. 3 or 4).

The first focal length f ₁ and the second focal length f ₂ may have different values. For example, the relay optical system 140 can enlarge the image-formed SLM 172 by making the second focal length f ₂ larger than the first focal length f ₁ . Alternatively, the relay optical system 140 may reduce the image-formed SLM 172 by making the first focal length f ₁ larger than the second focal length f ₂ . As will be described later, since the size of the formed SLM 172 is proportional to the viewing angle VA, it is possible to change the viewing angle by enlarging or reducing the formed SLM 172.

The noise removing filter 150 is disposed between the first focal distance f ₁ on the exit surface of the first relay lens 141 of the relay optical system 140 and the second focal distance f ₂ on the incident surface side of the second relay lens 143, May be disposed at or near the overlapping positions. The noise removing filter 150 may be, for example, a pin-hole. The noise removing filter 150 is located at the first focal length f ₁ of the first relay lens 141 of the relay optical system 140 and blocks the remaining light except the light of the desired diffraction order, Thereby removing noise such as a diffraction pattern or multiple diffraction due to the pixel structure of the diffraction grating 120.

As described above, the image of the hologram wavefront formed on the light-modulating surface of spatial light modulator 120 forms SLM 172 'imaged' by relay optics 140. The field lens 170 focuses the thus formed SLM 172 in front of the pupil 13 of the user's eye 11 to form the field of view window VW in front of the pupil of the user. The view window (VW) can be understood as a space where the user can view the holographic image. The arrangement position of the field lens 170 will be described later with reference to Figs. 3 and 4. Fig.

The optical path changer 180 may be a beam splitter that reflects the diffracted light transmitted from the relay optical system 140 and transmits the external light Lo as it is. The optical path changer 180 causes the light beam incident on the first incident surface 180a to be reflected by the beam separating film 181 located inside the optical path changer 180 and exit to the exit surface 180c, 180b may be configured to pass through the beam separating film 181 and exit to the first emitting surface 180c.

The beam splitter 181 of the optical path changer 180 may be, for example, a half mirror. In this case, the light illuminated by the light source unit 110 need not be limited to the polarized light.

As another example, when light illuminated in the light source section 110 is polarized, the beam separating film 181 of the optical path changer 180 may be a polarization selective reflecting film. For example, when the polarization direction of the light beam incident on the first incident surface 180a is referred to as a first polarization direction and the polarization direction orthogonal to the first polarization direction is referred to as a second polarization direction, (Hereinafter, light of the first polarized light) and transmit the light having the second polarized light direction (hereinafter referred to as the light of the second polarized light). Since the external light Lo can have both the first polarized light component and the second polarized light component, when the beam separating film 181 has the above-described polarization selectivity, the external light Lo incident from the second incident surface 180b, Only the second polarized component of the beam will pass through the beam splitting film 181 and reach the pupil 13 of the user's eye 11. [

The first incident surface 180a of the light path changer 180 may be disposed adjacent to the field lens 170. [ The exit surface 180c of the light path changer 180 may be disposed adjacent to the pupil 13 of the user's eye 11. [

The optical path changer 180 changes at least one of the optical path of the diffracted light of the hologram image transmitted from the relay optical system 140 and the optical path of the external light Lo to generate the diffracted light and the external light Lo To the same area (i.e., the pupil 13 of the user's eyes 11).

As described above, the perspective type holographic display device 100 of the present embodiment can be a wearable device worn on the head of the user (10 in Fig. 1), and the housing 190 can be attached to the user's eyes It may have a shape similar to that of the one-eyepiece eyeglass which can be attached closely to the site, or it may have a shape attached to the glasses.

For example, the housing 190 may include a first housing portion 190A adjacent to the ear, a bent portion 190B, and a second housing portion 190C adjacent the eye 11. The first housing portion 190A, the bent portion 190B, and the second housing portion 190C may be integrally formed, but are not limited thereto. The first housing portion 190A is provided with a light source portion 110, a spatial light modulator 120, a photomultiplier 130, a relay optical system 140, and a noise removing filter 150 . In the second housing portion 190C, for example, a field lens 170 and a light path changer 180 may be located. The bent portion 190B may be provided with a reflecting member 160 such as a total reflection prism or a simple mirror that turns the optical axis according to the shape of the housing 190. The second relay lens 143 of the relay optical system 140 and the noise elimination filter 150 are disposed on the second housing portion 190C in accordance with the size of the housing 190 and the focal length of the relay optical system 140 of the optical system . The second housing portion 190C includes a first window 191 provided at a position facing the user's eye 11 when the perspective type holographic display device 100 is worn by the user, And a second window 192 provided at a position opposite to the second window 191. The first and second windows 191 and 192 may be formed of glass or a transparent plastic material or may be an open portion of the second housing portion 190C. The optical path changer 180 is disposed such that the second incident surface 180b is positioned at a position adjacent to the second window 192. [ The external light Lo is incident on the optical path changer 180 through the second window 192 and reaches the user's eye through the optical path changer 180 and the first window 191. [ . In other words, the user can see the outside through the first window 191, the optical path changer 180, and the second window 192. Also, according to the above arrangement, the optical path changer 180 can be disposed adjacent to the user's eyes 11. [

Next, the arrangement of the field lens 170 will be described.

Fig. 3 is a view showing an example of the arrangement of the field lens 170. Fig. FIG. 3 shows the diffracted light for convenience as it is not deflected by the beam splitter 181 of the optical path changer (180 in FIG. 2). Referring to FIG. 3, the field lens 170 may be positioned at or near the imaged SLM 172. When the optical modulation surface of the spatial light modulator 120 is located at or near the incident surface side first focal length f ₁ of the first relay lens 141, the SLM 172, which has been imaged, the emission surface side a second focal length of the lens 143, the emission surface side a second focal length (f ₂₎ is the second relay lens 143, a bar, a field lens 170 to be formed in the position overlapping to the vicinity of (f ₂₎ May be disposed at or near the overlapping positions.

Fig. 4 is a view showing another example of the arrangement of the field lens 170. Fig. 4 also shows that the diffracted light is not deflected by the beam splitter 181 of the optical path changer (180 in FIG. 2) for convenience. 4, the field lens 170 is positioned such that the SLM 172 is between the front focus (object focus) Fo of the field lens 170 and the incident surface of the field lens 170 .

Next, with reference to FIG. 2 again, the operation of the perspective type holographic display device 100 will be described. First, the controller 900 generates a hologram data signal and provides the hologram data signal to the spatial light modulator 120. The hologram data signal may be a CGH (Computer Generated Hologram) signal calculated so that the desired hologram image is reproduced in space. The color hologram image can be implemented by RGB time division driving. For example, the control unit 900 sequentially drives the red, green, and blue light sources of the light source unit 110, and supplies the spatial light modulator 120 with hologram data signals corresponding to red, green, and blue hologram images The hologram images of red, green, and blue are sequentially displayed at a time so that the color hologram images can be displayed.

The spatial light modulator 120 may form a hologram pattern on the surface of the spatial light modulator 120 in accordance with the hologram data signal provided from the controller 900. The principle that the spatial light modulator 120 forms a hologram pattern can be, for example, the same as the principle that a display panel displays an image. For example, the holographic pattern allows to provide 0 light to be displayed in the spatial light modulator 120 in the form of an interference fringe having information of the holographic image to be reproduced. Then, by the hologram pattern formed in the spatial light modulator 120, the light becomes modulated diffracted light so as to have the hologram wave front on the surface of the spatial light modulator 120.

The diffracted light generated in the spatial light modulator 120 forms an SLM 172 imaged by the relay optical system 140. Since the spatial light modulator 120 is composed of an array of a plurality of pixels, an array of a plurality of pixels acts as a lattice. Thus, the incident light is diffracted and interfered not only by the hologram pattern formed in the spatial light modulator 120, but also by the pixel grid consisting of the array of pixels of the spatial light modulator 120. In addition, a part of the incident light is not diffracted by the holographic pattern of the spatial light modulator 120 but passes through the spatial light modulator 120 as it is. As a result, a plurality of lattice spots may appear on the pupil plane on which the field-of-view window (VW), in which the hologram image is gathered to the dots, is placed. Such a plurality of lattice points may degrade the image quality of the hologram image, As a video noise that makes it uncomfortable. The noise removing filter 150 is located at the first focal length f ₁ of the first relay lens 141 of the relay optical system 140 and blocks the remaining light except the light of the desired diffraction order, Thereby removing noise such as a diffraction pattern or multiple diffraction due to the pixel structure of the diffraction grating 120.

The field lens 170 focuses the formed SLM 172 to form a field of view window VW in front of the pupil 13 of the user's eye 11. [ That is, the field lens 170 allows the hologram wavefront formed by the relay optical system 140 (i.e., the imaged SLM 172) to be viewed as a three-dimensional hologram image while being diffracted and interfered in the field of view window VW.

On the other hand, since the beam splitter film 181 of the optical path changer (180 in Fig. 2) can transmit external light (Lo in Fig. 2) It becomes possible to simultaneously view a scene outside the window (192 in FIG. 2).

3, when the field lens 170 is disposed at or near the SLM 172 in which the image is formed, the image that the user 10 looks through the field lens 170 becomes the SLM 172 that has been imaged. That is, when the hologram image is reproduced, the user 10 can view the hologram image at the viewing position (viewing window VW) separated by d from the framed SLM 172. The viewing angle VA or the field of view (FOV) of the reproduced holographic image is determined by the size S of the formed SLM 172 and the distance from the SLM 172 to the view window VW Can be adjusted by the distance d. That is, when the size S of the formed SLM 172 increases, the viewing angle VA or the field of view FOV increases. When the size S of the formed SLM 172 decreases, the viewing angle VA or the field of view FOV decreases. Becomes smaller. The size S of the formed SLM 172 can be determined by the size of the spatial light modulator 120 and the magnification of the relay optical system 140. [ On the other hand, the shorter the distance d from the formed SLM 172 to the viewing window VW, the larger the viewing angle VA and the field of view FOV. The distance d from the formed SLM 172 to the field of view window VW may be determined by the F value (F / #) of the field lens 170. As described above, since the field lens 170 and the optical path changer 180 are arranged in contact with the pupil 13 of the user 10, the distance d from the formed SLM 172 to the view window VW is shortened So that the viewing angle VA or the visual field FOV can be increased.

The SLM 172 that is imaged as shown in Figure 4 may lie between the front focus F _o of the field lens 170 and the incident plane of the field lens 170. 5 is a view for explaining an operation according to the arrangement of the field lens of FIG. When the formed SLM 172 lies between the front focal point F _o of the field lens 170 and the incident surface of the field lens 170, the image seen through the field lens 170, as shown in Figure 5, And the fixed virtual image SLM 173 by the lens 170. [ At this time, the size S 'of the fixed virtual image SML 173 satisfies the following lens formula with respect to the size S of the formed SLM 172.

Where a is the distance between the imaged SLM 172 and the field lens 170 and b is the distance between the fixed virtual SLM 173 and the field lens 170 And f ₃ represents the front focal length of the field lens 170. [

The user 10 can view the hologram image at the viewing position (viewing window VW) which is distant from the still image SLM 173 by d '. At this time, the viewing angle VA or the field of view (FOV) of the reproduced holographic image can be adjusted by the size S 'of the fixed virtual image SLM 173 and the distance d'. That is, when the size S 'of the fixed virtual image SLM 173 increases, the viewing angle VA or the field of view FOV increases. When the size S' of the fixed virtual image SLM 173 decreases, The size S 'of the fixed virtual image SLM 173 can be determined by the positional relationship between the formed SLM 172 and the field lens 170, as can be seen from Equation (1) above. The field lens 170 is disposed so that the formed SLM 172 is located inside the front focal point F _o of the field lens 170. Further, The size S 'of the virtual SLM 173 can be made larger and the viewing angle VA or the field of view FOV can be made smaller as the front focus F _O of the SLM 173 closer to the SLM 172, Can be greatly increased.

As a holographic display device applied to a conventional head mounted display (HMD), an immersion type in which a hologram image is implemented using a complex spatial light modulator is known. However, the complex spatial light modulator requires a complicated structure, and the resolution is deteriorated. In addition, when the 2D image is expressed, the image quality deteriorates. In order to minimize the influence of high-order diffraction, an ultra-high resolution spatial light modulator is required, and the field of view (FOV) is limited to the size of the complex spatial light modulator. Therefore, in the case of the same resolution, a complex spatial light modulator having ultra-fine pixels has a relatively narrow field of view (FOV).

In contrast, the holographic display device 100 of the present embodiment can reduce the size S of the formed SLM 172 or the size S 'of the fixed virtual SLM 173 to the size of the spatial light modulator 120, The magnification of the relay optical system 140, the F value (F / #) of the field lens 170, and the position of the field lens 170) of the optical system, (VA) or field of view (FOV) is not limited by the size of the spatial light modulator 120.

In the above-described embodiment, RGB time division driving is used as an example to realize a color image, but the present invention is not limited thereto. As another example, the light source unit 110 may illuminate white light, and a spatial light modulator 120 may use a liquid crystal panel or the like having a built-in color filter to realize a color holographic image by space division.

Also, in the above-described embodiment, the parallel light is illuminated by the light source unit 110 has been described. In this case, the light source unit 110 may use a lens that emits or hits light instead of a collimator lens. In some cases, the light source unit 110 may use a field lens 170 may be omitted.

1 and 2 show a case in which the perspective type holographic display device 100 is worn toward the left eye 11L of the user 10 but can be applied to the case where the perspective type holographic display device 100 is worn toward the right eye 11R of the user 10. [ Of course it is. The perspective type holographic display device worn toward the right eye 11R can have a symmetrical structure of the perspective type holographic display device 100 worn toward the left eye 11L.

6 is a view schematically showing an optical system of a perspective type holographic display device 200 according to another embodiment. Referring to FIG. 6, the perspective type holographic display device 200 of the present embodiment includes the transmissive spatial light modulator 220, and the transmissive spatial light modulator 220 described in FIGS. 1 to 5 100). ≪ / RTI > The transmissive spatial light modulator 220 may use, for example, a light modulator using a liquid crystal device (LCD) or a semiconductor optical modulator based on a compound semiconductor such as GaAs. The light emitted from the light source unit 110 is diffracted and modulated while passing through the transmission spatial light modulator 220 and the diffracted light having passed through the transmission spatial light modulator 220 passes through the relay optical system 140, the field lens 170, Converges in front of the pupil 13 of the user's eye 11 through the converter 180 to form a view window VW.

7 is a view schematically showing an optical system of a perspective type holographic display device 300 according to still another embodiment. 7, the perspective type holographic display device 300 of this embodiment uses the active reflector 380 as the optical path changer, and the perspective view described with reference to Figs. 1 to 5, except that the active reflector 380 is used as the optical path changer. Type holographic display device 100 according to the present invention. The active reflector 380 is an optical component that can actively control reflection and transmission under the control of the control unit 901. [ As such active reflector 380, for example, a transmittance adjustment device using a liquid crystal (LC), an electro-chromic device, etc. may be used together with a (half) mirror. In addition, a thin film having a reflective coating or other additional function capable of increasing the amount of light directed toward the pupil 13 of the user 10 may be additionally provided on the surface of the beam separating film of the active reflector 380. By adopting the active reflector 380 as the optical path changer, the controller 901 can control the amount of light entering the pupil from the outside when the external environment is too bright to easily view the hologram image.

8 is a view schematically showing an optical system of a perspective type holographic display device 400 according to still another embodiment. 8, the perspective type holographic display device 300 of the present embodiment includes an optical path changer 480 such as the beam splitter described in the embodiment with reference to FIGS. 1 to 5, and a separate transmittance adjusting device 485 May be provided on the second incident surface 480b of the optical path changer 480. [ When the external environment is too bright and it is not easy to view the hologram image, the control unit 902 can control the external light incident from the outside through the second window 192 into the pupil through the use of the transparency adjusting device 485, It is possible to adjust the light amount of the light source Lo.

9 is a view schematically showing an optical system of a perspective type holographic display device 500 according to yet another embodiment, and FIG. 10 is a view for explaining the operation of a perspective type holographic display device 500 of this embodiment .

9, the perspective type holographic display device 500 of the present embodiment further includes a movable lens holder 546 capable of moving the second relay lens 543 of the relay optical system 540 in the optical axis direction 546a And is substantially the same as the perspective type holographic display device 100 described in the embodiment with reference to Figs. 1-5. The movable lens holder 546 includes a motor (not shown) and can move the second relay lens 543 in the optical axis direction 546a under the control of the control unit 903. [ As another example, the movable lens holder 546 may manually move the second relay lens 543 in the optical axis direction 546a.

Moving the second relay lens 543 in the optical axis direction 546a causes the size of the imaged SLM 172 formed by the relay optical system 540 to be adjusted as shown in Figure 10, Can be moved.

Specifically, the diffracted light formed by the spatial light modulator 120 by the first relay lens 541 of the relay optical system 540 is converged at the focal point on the exit surface side of the first relay lens 541, and then diverged. The second relay lens 543 is arranged such that the incident surface side focus position coincides with the exit surface side focus position of the first relay lens 541 like the perspective type holographic display device 100 described in the embodiments with reference to Figs. (Hereafter referred to as the home position), the size of the SLM 172 formed becomes S1. However, if the second relay lens 543 is moved in the direction 147 approaching the first relay lens 541 from the original position, the size S2 of the SLM 172 formed becomes smaller. As a result, the user sees the formed SLM 172 of a smaller size (S2), so that the viewing angle VA and the field of view FOV become smaller. Conversely, if the second relay lens 543 is moved away from the first relay lens 541, the size of the formed SLM 172 will be greater than S1, The view angle VA and the field of view FOV become large because the SLM 172 having a large size is seen. As described above, the perspective type holographic display device 500 of the present embodiment moves the lens position of the relay optical system 540, as in the embodiment referenced in FIG. It is also possible to adjust the field of view (FOV).

As described above, by moving the two relay lens 543 in the optical axis direction 546a, it is also possible to move the position of the formed SLM 172, as in the embodiment with reference to Fig. The position of the formed SLM 172 is set within the range of the inside of the front focus Fo of the field lens 170 (i.e., between the front focal point Fo of the field lens 170 and the incident surface of the field lens 170) (S 'in Equation (1)) of the fixed virtual image SML 173 may be adjusted to adjust the field of view (FOV).

On the other hand, if the field of view (FOV) is large, the pixel density (pixels per inch) of the hologram image deteriorates and the image quality is degraded. If the field of view (FOV) is narrowed, the PPI of the hologram image is increased and the image quality is improved.

11 is a view schematically showing an optical system of a perspective type holographic display device 600 according to still another embodiment. 11, the perspective type holographic display device 600 of the present embodiment employs a field reflector 670 instead of the field lens 170 described in the embodiments with reference to Figs. 1 to 5 And is substantially the same as the perspective type holographic display device 100 described in the embodiment with reference to Figs. 1 to 5.

The light path changing unit 680 may be a beam splitter and the beam splitting film 681 of the light path changing unit 680 may be formed by diffracting light incident on the first incident surface 680a, The external light Lo incident on the surface 680b is transmitted to the exit surface 680c and the light incident from the third surface 680d is positioned to be reflected toward the exit surface 680c. At this time, the third surface 680d is a surface opposed to the first incident surface 680a.

The field reflector 670 is disposed on the third surface 680d side of the optical path changer 680. [ The field reflector 670 may be disposed adjacent to the third side 680d of the optical path changer 680. [ The field reflector 670 may have a concave reflective surface with respect to the third side 680d of the optical path changer 680. The field reflector 670 can be understood as a field optical element, such as the field lens 170 described with reference to Figs. Therefore, the field reflector 670 can be arranged to correspond to the position of the field lens 170 described above. For example, the field reflector 670 may be arranged to be positioned in the vicinity of the image plane (172 in Fig. 3) where the hologram image transmitted from the relay optical system 140 is imaged. Or the field reflector 670 may be disposed so that the image plane 172 on which the hologram image transmitted from the relay optical system 140 is imaged is positioned inside the focal point of the field reflector 670. In other words, the field reflector 670 can be arranged to re-image the image plane 172 onto which the hologram image transmitted from the relay optical system 140 is imaged to the enlarged fixed virtual image.

The diffracted light passed through the relay optical system 140 is incident on the first incident surface 680a of the optical path changer 680 and passes through the beam splitting film 681 to the third surface 680d It is released. The diffracted light emitted from the third surface 680d is reflected by the field reflecting mirror 670 and is again incident on the third surface 680d of the optical path changer 680. After being reflected by the beam separating film 681, Plane 680c and directed to the pupil 13 of the user's eye 11. [ At this time, the diffracted light is incident on the field reflector 670 as a parallel light flux and focused by the field reflector 670 to form the field of view window VW in the pupil 13. The external light L0 is incident on the second incident surface 680b of the optical path changer 680 and then exits through the beam splitting film 681 through the exit surface 680c and enters the pupil of the user 10 Lt; / RTI >

12 is a view schematically showing an optical system of a perspective type holographic display device 700 according to still another embodiment. 12, the perspective type holographic display device 700 of the present embodiment may be replaced with a curved beam (not shown) instead of the field lens 170 and the optical path changer 180 described in the embodiments with reference to Figs. Is substantially the same as the perspective type holographic display device 100 described in the embodiment with reference to Figs. 1 to 5, except that an optical path changer 780 having a separation film 781 is employed.

The optical path changer 780 may be a beam splitter having a beam separating film 781 formed therein with a concave curved surface with respect to the first incident surface 801a. The light path changer 780 can have a shape in which two portions divided by the beam separating film 781 are bonded to each other with the beam separating film 781 as a boundary. At this time, two portions of the optical path changer 780 may have substantially the same refractive index.

The beam separating film 781 of the optical path changer 780 may be a half mirror. In this case, the light illuminated by the light source portion 710 need not be limited to the polarized light.

As another example, when the light illuminated in the light source portion 710 is polarized, the beam separating film 781 of the optical path changer 780 may be a polarization selective reflecting film. For example, the beam separating film 781 may have polarization selectivity that reflects the light incident on the first incident surface 780a (i.e., the light of the polarized light emitted from the light source 110) and transmits the light of the second polarized light . Since the external light Lo can have both the first polarization component and the second polarization component orthogonal to the first polarization direction, when the beam separating film 781 has the above-described polarization selectivity, the second incident face 780b, Only the second polarized component of the external light Lo incident on the beam splitter 781 will reach the pupil 13 of the user's eye 11 through the beam splitting film 781. [

The curved surface of the beam separating film 781 can be formed such that the light beam incident on the first incident surface 780a is reflected while being reflected by the beam separating film 781 so that the viewing window VW is formed in front of the pupil 13 of the user's eye 11 . The convergence of the light beam by the beam separating film 781 replaces the function of the field lens 170 described with reference to Figs. 1 to 10 and the field reflector 670 described with reference to Fig. Therefore, the light path changer 780 can be disposed such that the beam separating film 781 is positioned corresponding to the position of the field lens 170 described above. For example, the optical path changer 780 may be disposed such that the beam separating film 781 is positioned near the image plane (172 in Fig. 3) on which the hologram image transmitted from the relay optical system 140 is imaged. Or the optical path changer 780 may be disposed so that the image plane 172 on which the hologram image transmitted from the relay optical system 140 is formed is positioned inside the focus of the beam separating film 781. [ In other words, the optical path changer 780 can be arranged to re-image the image plane 172 on which the hologram image transmitted from the relay optical system 140 is formed, to the enlarged fixed virtual image.

On the other hand, since the two portions of the optical path changer 780 with the boundary of the beam separating film 781 have substantially the same refractive index, when the external light Lo passes through the beam separating film 781, Do not. In other words, since the external light Lo passes through the beam separating film 781 without bending, the user can see the external scene without distortion.

13 is a view schematically showing an optical system of a perspective type holographic display device 800 according to still another embodiment.

13, the optical system of the perspective type holographic display device 800 of the present embodiment is a perspective type optical system as described in the embodiment with reference to FIG. 12, except that it further includes a light beam- Is substantially the same as the optical system of the graphic display device 700, and therefore differences will be mainly described.

The light source unit 110 illuminates light having polarized light. 2, when the light source unit 110 illuminates light having a polarization, the light source 130 may be a polarizing beam splitter, and may be disposed between the light source 130 and the spatial light modulator 120 A polarization conversion member such as a quarter wave plate (not shown) may be further disposed. The optical path changer 880 has a beam separating film 881 having polarization selectivity and formed with a predetermined curved surface. 12, the beam separating film 881 reflects the light of the first polarized light (that is, the light of the polarized light emitted from the light source 110) incident on the first incident surface 880a, And may have polarization selectivity through which light of polarized light is transmitted. Since the external light Lo can have both a component of the first polarized light and a component of the second polarized light orthogonal to the first polarized direction, only the second polarized light component of the external light Lo passes through the beam separation membrane 881 And will reach the pupil 13 of the user's eyes 11. As described later, the light beam-selective optical element 890 may have a positive refractive power only for the first polarized light and not have the refractive power for the second polarized light. Therefore, the curved surface of the beam separating film 881 can be designed in consideration of the refracting power of the optical beam selecting optical element 890.

14 shows an example of a light beam-selective optical element 890 employed in the perspective type holographic display device 800 of FIG. 13, in which a light beam-selective optical element 890 is provided with a first polarized light beam and a second polarized light beam Dependent polarization type lens having different refractive indexes. 14, the optical beam-selective optical element 890 may be a cemented lens in which the first lens unit 891 and the second lens unit 892 are joined. The first lens unit 891 is an isotropic lens formed of, for example, glass or an isotropic polymer material, and the second lens unit 892 is an anisotropic lens formed of an anisotropic polymer material having a different refractive index according to the polarization direction. . The second lens portion 892 of the anisotropic polymer has a refractive index different from that of the first lens portion 891 with respect to light of the first polarized light and has a refractive index different from that of the first lens portion 891 with respect to light of the second polarized light. May be formed to have a refractive index that is substantially equal to the refractive index of the substrate. The incident surface 890a of the optical-beam-selective optical element 890 (that is, the incident surface of the first lens portion 891) and the exit surface 890c of the optical-beam-selective optical element 890 ) May be a flat surface. An interface 890b between the first lens portion 891 and the second lens portion 892 is formed into a curved surface having a predetermined curvature. The curved surface of the boundary surface 890b is formed such that the light beam of the first polarized light incident on the incident surface 890a of the optical beam selective optical element 890 is focused and the viewing window VW is formed in front of the pupil 13 of the user's eye 11 .

Next, the operation of the perspective type holographic display device 800 of this embodiment will be briefly described.

The light having the polarized light illuminated by the light source unit 110 is diffracted with predetermined hologram image information via the spatial light modulator 130 and passes through the relay optical system 140 and the noise removing filter 150, Is incident on the first incident surface 880a of the first polarizing plate 880 as diffracted light of the first polarized light. The light path changer 880 is reflected by the beam separating film 881 with respect to the diffracted light of the first polarized light, is converged by the curvature of the beam separating film 881, and exits through the emitting surface 880c. The diffracted light of the first polarized light emitted from the optical path changer 880 is focused on the optical beam selective optical element 890 to form the field of view window VW in front of the pupil 13 of the user's eye 11, .

The external light Lo is incident on the second incident surface 880b of the optical path changer 880 and only the light of the second polarized light perpendicular to the first polarized light out of the external light Lo passes through the beam of the optical path changer 880 Passes through the separation membrane 881, and exits through the exit surface 880c. The external light Lo of the second polarized light emitted from the optical path changer 880 passes through the optical beam selective optical element 890 without being refracted so that the user can see the external scene without distortion.

In this embodiment, since the optical path converter 880 and the optical-beam-selecting optical element 890 are designed to distribute the refractive power with respect to the light of the first polarized light, it is more free from the freedom of optical design, Can be made sufficiently large. In some cases, the beam splitting film 881 of the optical path changer 880 may be formed as a flat surface when the light beam-selective optical element 890 can sufficiently take charge of the refracting power.

Figs. 15A to 15C are views showing other examples of optical beam-selective optical elements employed in the perspective type holographic display device 800 of Fig.

Figs. 15A to 15C are views showing other examples of optical beam-selective optical elements employed in the perspective type holographic display device 800 of Fig.

15A, a light beam-selective optical element 990 includes opposed first and second transparent substrate layers 991 and 992, a liquid crystal layer (not shown) interposed between the first and second transparent substrate layers 991 and 992, (994). At least one of the surfaces of the first and second transparent substrate layers 991 and 992 facing each other is curved so that the optical beam selective optical element 990 has a predetermined refractive power depending on whether the liquid crystal layer 994 is oriented or not . First and second electrodes 996 and 997 may be provided on the first and second transparent substrate layers 991 and 992, respectively. The first and second electrodes 996 and 997 are energized by a power source 998 and the liquid crystals of the liquid crystal layer 994 can be aligned by an applied voltage. Reference numeral 995 denotes a partition wall for sealing the liquid crystal layer 994. Since the refractive index and the polarization characteristic of the liquid crystal layer 994 can be changed according to the liquid crystal alignment in the liquid crystal layer 994, the light beam-selective optical element 990 of this embodiment can be an active lens. For example, the liquid crystal layer 994 may transmit both the first polarized light and the second polarized light as they are, without applying a voltage, so that the user can see both the holographic image and the external scene. In addition, the liquid crystal layer 994 may be focused while transmitting only the first polarized light in a state where a voltage is applied, so that the user can view only the hologram image. As another example, if the liquid crystal layer 994 is designed to transmit only the second polarized light when a voltage is applied to the liquid crystal layer 994, the liquid crystal layer 994 can emit light of both the first polarized light and the second polarized light So that the user can see both the hologram image and the external scene and the liquid crystal layer 994 allows the light to be focused while transmitting only the second polarized light in a state where the voltage is applied, It might be.

15A shows a case where the inner surface of the second transparent substrate layer 992 (that is, the surface on which the second electrode 997 is provided) is formed into a curved surface. However, when the first transparent substrate layer 991 is curved Of course. Although the first and second electrodes 996 and 997 are provided on the opposite surfaces of the first and second transparent substrate layers 991 and 992, the present invention is not limited thereto.

FIG. 15B shows a modification of the optical beam-selective optical element 990 of FIG. 15A. Referring to FIG. 15B, a light beam-selective optical element 990 'includes opposed first and second transparent substrate layers 991' and 992 'and first and second transparent substrate layers 991' and 992 ' And a liquid crystal layer 994 'interposed in the liquid crystal layer 994'. First and second electrodes 996 'and 997' may be provided on the first and second transparent substrate layers 991 'and 992', respectively. The first and second electrodes 996 'and 997' are energized by a power source 998 'and the liquid crystals of the liquid crystal layer 994' may be aligned by an applied voltage. The polarization characteristic of the liquid crystal layer 994 'may be changed depending on the voltage application. The liquid crystal layer 994 'is sealed by the partition 995'.

At least one of the first and second transparent substrate layers 991 'and 992' may be a cemented lens. For example, as shown in FIG. 15B, the second transparent substrate layer 992 'may be formed by bonding a first lens layer 992a' and a second lens layer 992b 'having different refractive indices . At this time, the second transparent substrate layer 992 'may have a planar shape as a whole, and a bonding surface of the first lens layer 992a' and the second lens layer 992b 'may be a second transparent substrate layer 992' And may have a convex shape with respect to the incident surface so as to have a positive refractive power. Depending on the refractive indexes of the first lens layer 992a 'and the second lens layer 992b', the shape of the bonding surface may vary. Such a second transparent substrate layer 992 'is formed by a first lens layer 992a' made of an isotropic material and a second lens layer 992b 'made of an isotropic material, like the light beam selective optical element 890 described with reference to Fig. Is made of an anisotropic material and may have a different refractive index with respect to light of the first polarized light (i.e., diffracted light) and light of the second polarized light (i.e., external light).

The light beam-selective optical element 990 'of the present embodiment differs from the optical beam-selective optical element 990' described with reference to FIG. 15A in that the second transparent substrate layer 992 ' Device 990 differs from device 990.

Fig. 15C shows another modification of the optical beam-selective optical element 990 of Fig. 15A. . Referring to Figure 15C, a light beam-selective optical element 990 "is disposed between opposing first and second transparent substrate layers 991 ", 992 " and first and second transparent substrate layers 991 & The liquid crystal layer 994 " First and second electrodes 996 "and 997" may be provided on the first and second transparent substrate layers 991 "and 992 ", respectively. The first electrode 996 "is provided over the entire surface of the first transparent substrate layer 991 ", while the second electrode 997" is a portion of the front surface of the second transparent substrate layer 992 " The first and second electrodes 996 ", 997 "may be provided by a power source 998" A voltage is applied and the liquid crystals of the liquid crystal layer 994 "can be aligned by the applied voltage. The liquid crystal layer 994" is sealed by the partition 995 ".

The electric field applied to the liquid crystal layer 994 " becomes non-uniform because the shape and arrangement position of the second electrode 997 "is different from the shape and arrangement position of the first electrode 996 ". For example, The electric field on the edge side of the second electrode 997 "has a fringing-field when the transparent electrode 997" is provided on the periphery or both sides of the second transparent substrate layer 992 ". Accordingly, when the shape, the arrangement position, and the applied voltage of the second electrode 997 "are appropriately selected, the liquid crystal layer 994 " is positively (+) formed by the non-uniform electric field applied to the liquid crystal layer 994 & The liquid crystal layer 994 "can transmit both the first polarized light and the second polarized light as it is without applying a voltage, so that the user can see both the holographic image and the external scene Can be seen. In addition, the liquid crystal layer 994 " can transmit only light of the first polarized light while being focused, thereby allowing the user to view only the hologram image.

16 is a plan view schematically showing an example in which a head mounted display device (perspective holographic display device) 700 according to still another embodiment is worn by the user 10, and Fig. 17 is a plan view of the head mounted display Figure 7 is a schematic diagram of an optical system of the apparatus 700;

Referring to FIG. 16, the head mounted display device 700 of the present embodiment may be a device that is worn on the head of the user 10, such as a pair of glasses or goggles, or attached to glasses or goggles.

The head mounted display device 700 includes a left eye perspective type display device 701, a right eye perspective type display device 702 and a frame connecting the left eye perspective type display device 701 and the right eye perspective type display device 702 803). Each of the left-eye perspective type display device 701 and the right-eye perspective type display device 702 may be a perspective type holographic display device of any one of the embodiments described with reference to FIGS. When the head-mounted display device 700 is worn on the head of the user 10, the optical path changer 781 of the left-eye type holographic display device 701 is positioned adjacent to the left eye 11L of the user 10 And the optical path changer 782 of the right-eye perspective type holographic display device 702 can be arranged to be located in the right eye 11R of the user 10. [ Each of the left-eye perspective type display device 701 and the right eye perspective type display device 702 can display a left eye hologram image and a right eye hologram image. In addition, since each of the left-eye perspective type display device 701 and the right-eye perspective type display device 702 is of a perspective type, the head-mounted display device 700 of this embodiment is a perspective type .

The control unit 904 for controlling the optical systems of the left-eye and right-eye perspective display apparatus 701 and the right-eye perspective display apparatus 702 includes a housing 901 for either the left eye perspective type display apparatus 701 or the right eye perspective type display apparatus 702, Or may be provided on the outside.

There may be slight differences in pupil location for each user. Therefore, in order to position the viewing window VW in the pupil of the user, a configuration for adjusting the position of the viewing window VW formed in each of the left-eye and right-eye perspective display device 701 and 702 Is required. Thus, the frame 703 is configured to move at least one of the left-eye perspective type display device 701 and the right-eye perspective type display device 702 in the left-right direction 704 so that the left-eye perspective type display device 701 and the right- The distance between the devices 702 is narrowed or increased. Such a fixing device of the frame 703 can take a known manner. Since the optical system of the left-eye perspective type display device 701 and the optical system of the right-eye perspective type display device 702 are individually provided, the head-mounted display device 700 of the present embodiment has the left-eye perspective type display device 701, The distance between the right-eye perspective type display device 702 can be easily adjusted.

Although the embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. It will be appreciated that other embodiments are possible. Accordingly, the true scope of the present invention should be determined by the appended claims.

100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1001, 1002:
110: light source 111: light source
112: collimator lens 113: reflective member
120, 220: spatial light modulator 130:
140, 540: relay optical system 141, 143, 541, 543: relay lens
150: Noise elimination filter 160: Reflecting member
170: field lens 172: formed SLM
173: Orthopedic Beauty SLM
180, 380, 480, 680, 781, 782, 880: optical path changer 485:
180a, 180b, 680a, 680b, 880a, 880b:
180c, 680c, and 880c: emitting surfaces 181, 681, and 881:
190: housing 191, 192: window
546: Operation lens holder 670: Field reflector
700: Head mounted display device
703: Frame 900, 901, 902, 903, 904:
880, 990, 990 ", 990 ": optical beam-selective optical element
994, 994 ', 994 ": liquid crystal layer 10: user
11, 11L, 11R: eye 13: pupil

Claims (30)

A light source for providing light;
A spatial light modulator for diffracting the light to reproduce a hologram image;
A relay optical system for enlarging or reducing the holographic image reproduced by the spatial light modulator and transmitting the holographic image;
A noise removing filter for removing noise from the diffracted light of the hologram image transmitted through the relay optical system; And
And a light path changer for changing at least one of an optical path of the diffracted light of the hologram image transmitted from the relay optical system and an optical path of the external light and transmitting the diffracted light and the external light to the same area. The method according to claim 1,
And a collimator for converting the light provided from the light source into a parallel light flux. The method according to claim 1,
Wherein the spatial light modulator is an amplitude modulated spatial light modulator or a phase modulated spatial light modulator. The method according to claim 1,
Wherein the relay optical system includes a first optical element into which a hologram image modulated by the spatial light modulator is incident and a second optical element including a second optical element with an incident surface side second focus in the vicinity of the first focal point on the exit surface of the first optical element, Type holographic display device. 5. The method of claim 4,
Wherein the first optical element has a first focal length and the second optical element has a second focal distance different from the first focal distance. 5. The method of claim 4,
Wherein the noise elimination filter is disposed in the vicinity of the first focal point on the emission surface side of the first optical element. The method according to claim 1,
Wherein the noise reduction filter is a diaphragm. The method according to claim 1,
And a field optical element for focusing the holographic image transmitted from the relay optical system. 9. The method of claim 8,
Wherein the field optical element is positioned in the vicinity of an image plane on which a hologram image transmitted from the relay optical system is imaged. 9. The method of claim 8,
Wherein the field optical element is disposed such that an image plane on which the hologram image transmitted from the relay optical system is imaged is positioned between an incident surface side focal position of the field optical element and an incident surface of the field optical element. 11. The method of claim 10,
Wherein the field optical element is arranged to re-image the image plane on which the hologram image transmitted from the relay optical system is formed to a fixed virtual image. 9. The method of claim 8,
Wherein the field optical element is disposed adjacent to the optical path changer. 9. The method of claim 8,
And changing the distance between the relay optical system and the field optical element to adjust the size of the holographic image transmitted from the relay optical system. 9. The method of claim 8,
The optical path changer includes a first surface on which diffracted light of a hologram image transmitted from the relay optical system is incident, a second surface on which external light is incident, and a third surface opposite to the second surface, And a beam splitter which reflects at least a part of the diffracted light of the hologram image incident on the first surface to the third surface and transmits at least a part of external light incident on the second surface to the third surface,
Wherein the field optical element is a field lens disposed adjacent to the first side of the optical path changer. 9. The method of claim 8,
The optical path changer includes a first surface on which diffracted light of a hologram image transmitted from the relay optical system is incident, a second surface on which external light is incident, a third surface opposite to the second surface, At least a part of the diffracted light of the hologram image incident on the first surface is transmitted through the fourth surface and the diffracted light of the hologram image re-incident on the second surface is incident on the fourth surface, And a beam splitter which reflects at least a part of external light incident on the second surface to the third surface,
Wherein the field optical element is a concave reflector disposed adjacent to the fourth surface of the optical path changer. 9. The method of claim 8,
Wherein the optical path changer is a half mirror and the field optical element is a field lens positioned between the relay optical system and the optical path changer and disposed adjacent to the optical path changer. The method according to claim 1,
The optical path changer includes a first surface on which diffracted light of a hologram image transmitted from the relay optical system is incident, a second surface on which external light is incident, and a third surface opposite to the second surface, And a beam splitter which reflects at least a part of the diffracted light of the hologram image incident on the first surface to the third surface and transmits at least a part of external light incident on the second surface to the third surface,
Wherein the beam splitting film has a concave curved shape with respect to the first surface and is focused while reflecting the hologram image transmitted from the relay optical system to the third surface. 18. The method of claim 17,
Wherein the light path changer is disposed such that the beam separating film is positioned in the vicinity of an image plane on which a hologram image transmitted from the relay optical system is imaged. 18. The method of claim 17,
Wherein the beam separating film is a polarization selective reflective film. 18. The method of claim 17,
And a light beam-selective optical element for focusing the diffracted light and transmitting external light. 21. The method of claim 20,
Wherein the light beam-selective optical element is a cemented lens of an isotropic lens and an anisotropic lens, the refractive power of the cemented lens has a positive value with respect to diffracted light, and the total refractive power of the cemented lens with respect to external light is zero A perspective type holographic display device. 21. The method of claim 20,
Wherein the optical beam-selective optical element includes first and second transparent substrate layers opposed to each other, and a liquid crystal interposed between the first and second transparent substrate layers, wherein at least one of the first and second transparent substrate layers Wherein the liquid crystal is controlled by electrodes to selectively have polarization characteristics. 21. The method of claim 20,
Wherein the optical beam-selective optical element includes first and second transparent substrate layers opposed to each other, and a liquid crystal interposed between the first and second transparent substrate layers, wherein at least one of the first and second transparent substrate layers Wherein the active matrix type liquid crystal display device is an active liquid crystal lens in which the liquid crystal is controlled by electrodes to selectively have a refractive power. The method according to claim 1,
Wherein the optical path changer is an active reflector for adjusting the amount of light transmitted through the external light. 22. The method of claim 21,
Wherein the active reflector includes any one of a liquid crystal filter and an electrochromic device for adjusting an amount of light transmitted through external light. The method according to claim 1,
Wherein the light path changer is disposed in the vicinity of a viewer's pupil. The method according to claim 1,
Wherein the perspective type holographic display device is installed in a head mounted housing which is worn on at least one of left and right eyes of a viewer's head. A head mounted display device for displaying a hologram image,
A left eye perspective holographic display device;
A right eye perspective holographic display device; And
And a frame connecting the left-eye perspective type holographic display device and the right eye perspective type holographic display device,
Wherein each of the left-eye perspective type holographic display device and the right eye perspective type holographic display device is a perspective type holographic display device according to any one of claims 1 to 27. 29. The method of claim 28,
When the head-mounted display device is worn on the user's head, the optical path changer of the left-eye perspective type holographic display device is located adjacent to the left eye of the user, and the optical path changer of the right- The display device being located adjacent to the right side of the display device. 29. The method of claim 28,
Wherein a distance between the optical path changer of the left-eye perspective type holographic display device and the optical path changer of the right-eye perspective type holographic display device is adjusted.

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