KR20220079441A - Mid-air image device and method for operating the same - Google Patents

Abstract

An aerial image display apparatus and an operating method thereof are disclosed.
The disclosed aerial image display device includes a projection system, at least one positive lens, at least one light propagation module, the at least one light propagation module comprising: a first transmission grating, a second transmission grating, at least one waveguide, and Includes a reflective grating.

Description

Aerial image display device and its operation method

An exemplary embodiment relates to an integrated optical device, to an aerial image display device for displaying an aerial image in free space, and to an operating method thereof.

In the field of mobile technology, there is an increasing need for creative solutions with high information content and comfort. One of the technical needs for implementation is the miniature aerial image display. A small aerial image display is required to be able to display the image without additional scattering media. These displays require high-quality magnified images and a secure, contactless user interface.

In addition, there is a need for an aerial image display device with a small size, wide field of view, and high-definition image that can be placed on a mobile device, and the aerial image display device needs no diffusion screen and no moving parts.

An exemplary embodiment provides a compact aerial image display device for displaying a high-quality enlarged image.

An exemplary embodiment provides a method of operating an aerial image display device capable of displaying a high-quality enlarged image.

Aerial image display device according to an exemplary embodiment,

projection system;

at least one positive lens;

at least one light propagation module,

the at least one light propagation module includes a first transmission grating, a second transmission grating, at least one waveguide, and a reflection grating;

each of the at least one positive lens disposed to cover each of the at least one light propagation module.

The projection system is located above the at least one positive lens, the positive lens is located above the waveguide of the at least one optical propagation module, and the first transmission grating, the reflection grating, and the second transmission grating are below the waveguide in this order can be placed as

The projection system may be located below the at least one positive lens, the at least one positive lens may be located below the waveguide, and a first transmission grating, a second transmission grating, and a reflection grating may be disposed on the waveguide in this order.

wherein the projection system is positioned over at least one positive lens positioned over a first transmission grating of the at least one light propagation module, a waveguide positioned below the first transmission grating, and a second transmission grating and a reflective grating positioned below the waveguide. can

the at least one positive lens is positioned below a reflective grating of at least one light propagation module, the first transmission grating, the second transmission grating and the waveguide positioned above the reflective grating, and wherein the at least one light propagation module comprises a projection system may be located below.

wherein the at least one positive lens is positioned above the reflective grating of the at least one light propagation module, the second transmission grating, the first transmission grating and the waveguide are disposed below the reflective grating in order, the projection system comprising: It may be located below the light propagation module.

wherein the at least one positive lens is positioned under a reflective grating of the at least one light propagation module, and a second transmission grating, a waveguide, and a first transmission grating are positioned above the reflective grating in this order, and wherein the projection system comprises the at least one light It may be located above the propagation module.

Each of the at least one waveguide may be configured as a sector of an optical transmission diffraction multidirectional radial waveguide based on total internal reflection.

The light propagation module may further include a prism for light in-coupling.

The first transmission grating, the second transmission grating, and the reflection grating may be a volume holographic grating recorded on a film and deposited on the surface of the waveguide, or a relief diffraction element formed on the surface of the waveguide.

Each of the at least one optical propagation module may have the shape of one disk sector, and the at least one optical propagation module may be configured to have a disk shape as a whole.

Each of the at least one positive lens may have the shape of one disk sector, a radius of the disk sector coincides with a radius of a corresponding light propagation module, and the light propagation module may be covered by a corresponding positive lens.

The at least one positive lens may be gathered to form a circular lens array.

Each of the at least one positive lens may be configured to cover a corresponding light propagation module with a gap.

The gap may be filled with a layer of optical material.

Each of the at least one positive lens may have a shape matching the shape of the corresponding light propagation module.

The at least one positive lens may have one of a truncated circular sector shape, a polygonal shape, and a circular shape.

The waveguide may be formed of a material that is transparent to a visible light spectrum.

The at least one light propagation module may be configured to perform radial propagation of a decoupling aperture of the projection system.

One of an anti-reflective coating, a semi-reflective coating, a dichroic filter, a neutral filter, and a diffractive optical element may be provided on the surface of the waveguide.

Each of the at least one light propagation module may be configured to propagate light of a specific at least one color.

The at least one waveguide may have one of a shape of a sphere, a torus, a rectangular parallelepiped, a disk, and a star.

The at least one positive lens may be one of a Fresnel lens or a dynamic lens.

A method of operating an aerial image display device according to an exemplary embodiment,

an image forming beam from the projection system is transmitted to a first transmission grating, and as a result of diffraction, the beams are split into 1st order diffracted beams (a) and 0th order diffracted beams;

the 0th order diffracted beams are transmitted to a second transmission grating, and as a result of the diffraction the beams are split into a 1st order diffracted beam (b) and a 0th order diffracted beam;

transmitting the first-order diffracted beam (a), the first-order diffracted beam (b), and the zero-order diffracted beam to a waveguide;

The first-order diffracted beam (a) transmitted to the waveguide at an angle corresponding to the total internal reflection angle range, the first-order diffracted beam (b) is re-evaluated at the media boundary between the air/first transmission grating and between the waveguide/reflection grating. reflected and propagated along the waveguide, forming a first order diffracted beam c from a second transmission grating as a result of diffraction of the first order diffracted beam a, wherein the first diffracted beam b forming a first order diffracted beam (d) from the grating;

the first diffracted beam (c) and the first diffracted beam (d) being diffracted by a reflection grating and out-coupled to the positive lens through the waveguide, a second transmission grating and a first transmission grating; and

and refracting the out-coupled beam by the positive lens and focusing the aerial image on a focal plane.

The 0th order diffracted beam passes through a waveguide above the reflective grating, the beams are split into a 1st order diffracted beam (e) and a 0th order diffracted beam, and then the 0th order diffracted beam may not be considered.

the first diffracted beam (e) passes through a waveguide, a second transmission grating and a first transmission grating, and due to total internal reflection from a surface of the first transmission grating, the beams are reflected back into the waveguide; The first-order diffracted beam (e) is transmitted to the first transmission grating, and as a result of diffraction, the beams may be split into the first-order diffracted beam (a) and the zero-order diffracted beam (b).

The light propagation module may be configured such that the aerial image is visible only within a range perpendicular to the display device.

The light propagation module may be configured such that the aerial image display device is visible in both a range perpendicular to the aerial image display device and a range out of the vertical to the aerial image display device.

Aerial image display device according to an exemplary embodiment,

reflective grating;

a first positive lens positioned below the reflective grating;

a waveguide provided on the reflective grating;

a second transmission grating provided over the waveguide;

a first transmission grating provided on the second transmission grating;

a second positive lens provided on the first transmission grating; and

and a projection system provided on the second positive lens.

A method of operating an aerial image display apparatus according to an exemplary embodiment,

A) a beam forming an image from the projection system is transmitted to a first transmission grating, and as a result of diffraction, the beams are split into 1st order diffracted beams (a) and 0th order diffracted beams;

B) the 0th order diffracted beams are transmitted to a second transmission grating, and as a result of the diffraction the beams are split into a 1st order diffracted beam (b) and a 0th order diffracted beam;

C) transmitting the first-order diffracted beam (a), the first-order diffracted beam (b), and the zero-order diffracted beam to a waveguide;

D) the first-order diffracted beam (a) transmitted to the waveguide at an angle corresponding to the total internal reflection angle range, the first-order diffracted beam (b) is the media boundary between the air/first transmission grating and the waveguide/reflection grating is reflected back from and propagates along the waveguide, forming a first-order diffracted beam c from the second transmission grating as a result of diffraction of the first-order diffracted beam a, and the first-order diffracted beam b forming a first order diffracted beam (d) from the grating;

E) the 1st order diffracted beam (c) and 1st order diffracted beam (d) are diffracted in a reflection grating and out-coupled to a second positive lens through a waveguide, a second transmission grating and a first transmission grating;

F) the first positive lens focuses the beam outcoupled to its focal plane by forming a first aerial image, and the second positive lens focuses the beam outcoupled to its focal plane by forming a second aerial image Focusing on the; includes.

The 0th order diffracted beam may pass through a waveguide above the reflective grating, the beams may be split into 1st order diffracted beam e and 0th order diffracted beam, and then the 0th order diffracted beam may not be considered.

The first order diffracted beam e passes through a waveguide, a second transmission grating and a first transmission grating, and due to total internal reflection from the outer surface of the first transmission grating, these beams are reflected back into the waveguide, the first order The diffracted beam e is transmitted to the first transmission grating, and as a result of the diffraction the beams are split into a 1st order diffracted beam a and a 0th order diffracted beam b, and then the steps (B)-(I) ) can be repeated.

The aerial image display apparatus according to an exemplary embodiment may display a high-quality enlarged image. The aerial image display apparatus may be configured to be compact by having a plurality of diffraction gratings.

Fig. 1 shows an aerial image display apparatus according to an exemplary embodiment.
Fig. 2 shows a cross-sectional view of an aerial image display device according to an exemplary embodiment.
Fig. 3 is a diagram for explaining the operation of an aerial image display apparatus according to an exemplary embodiment.
4A, 4B, and 4C show various arrangement structures of an aerial image display apparatus according to an exemplary embodiment.
5A illustrates an example in which an aerial image display apparatus according to an exemplary embodiment includes two positive lenses.
5B is a diagram for explaining an operation when an aerial image display apparatus includes two positive lenses according to an exemplary embodiment.
6A, 6B, and 6C show various arrangement structures of the light multiplication module provided between the projection system and the positive lens.
Fig. 7A shows that one aerial image is formed in the aerial image display apparatus according to an exemplary embodiment.
7B is a diagram illustrating the formation of a plurality of aerial images in the aerial image display apparatus according to an exemplary embodiment.
8 shows a display device equipped with two sets of light propagation modules.
9A shows an aerial image display device including a prism.
9B shows a light propagation module having a concentric circle structure.
Fig. 10 shows an aerial image display apparatus according to another exemplary embodiment.
11A shows an example of a positive lens array divided into a plurality of sectors.
11B is a diagram illustrating an aerial image display apparatus applied to a mobile device to display an image having a 360-degree viewing angle according to an exemplary embodiment.
12A to 12J show various examples of positive lenses covering the light propagation module.
13A shows an example of a simulation model.
13B shows an aerial image obtained through a simulation model.
14 shows a vector diagram of diffraction gratings according to an exemplary embodiment.

Hereinafter, various embodiments of the present document will be described with reference to the accompanying drawings. However, it is not intended to limit the technology described in this document to specific embodiments, and it should be understood to include various modifications, equivalents, and/or alternatives of the embodiments of this document. . In connection with the description of the drawings, like reference numerals may be used for like components.

The electronic device according to various embodiments disclosed in this document may have various types of devices. The electronic device may include, for example, a portable communication device (eg, a smart phone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, or a home appliance device. The electronic device according to the embodiment of the present document is not limited to the above-described devices.

The various embodiments of this document and terms used therein are not intended to limit the technical features described in this document to specific embodiments, but it should be understood to include various modifications, equivalents, or substitutions of the embodiments. In connection with the description of the drawings, like reference numerals may be used for similar or related components. The singular form of the noun corresponding to the item may include one or more of the item, unless the relevant context clearly dictates otherwise. As used herein, "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "A , B, or C" each may include any one of the items listed together in the corresponding one of the phrases, or all possible combinations thereof. Terms such as "first", "second", or "first" or "second" may be used simply to distinguish the element from other elements in question, and may refer to elements in other aspects (e.g., importance or order) is not limited. It is said that one (eg, first) component is "coupled" or "connected" to another (eg, second) component, with or without the terms "functionally" or "communicatively". When referenced, it means that one component can be connected to the other component directly (eg by wire), wirelessly, or through a third component.

The term “module” used in various embodiments of this document may include a unit implemented in hardware, software, or firmware, and is interchangeable with terms such as, for example, logic, logic block, component, or circuit. can be used as A module may be an integrally formed part or a minimum unit or a part of the part that performs one or more functions. For example, according to an embodiment, the module may be implemented in the form of an application-specific integrated circuit (ASIC).

Various embodiments of the present document may be implemented as software including one or more instructions stored in a machine. For example, the processor of the device may call at least one of the one or more instructions stored from the storage medium and execute it. This makes it possible for the device to be operated to perform at least one function according to the called at least one command. The one or more instructions may include code generated by a compiler or code executable by an interpreter. The device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-transitory' only means that the storage medium is a tangible device and does not contain a signal (eg, electromagnetic wave), and this term refers to cases in which data is semi-permanently stored in the storage medium and temporary It does not distinguish the case where it is stored as

According to an embodiment, the method according to various embodiments disclosed in this document may be included and provided in a computer program product. Computer program products may be traded between sellers and buyers as commodities. The computer program product is distributed in the form of a machine-readable storage medium (eg compact disc read only memory (CD-ROM)), or via an application store (eg Play Store ^TM ) or on two user devices ( It can be distributed (eg downloaded or uploaded) directly between smartphones (eg: smartphones) and online. In the case of online distribution, at least a part of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium such as a memory of a server of a manufacturer, a server of an application store, or a relay server.

According to various embodiments, each component (eg, module or program) of the above-described components may include a singular or a plurality of entities, and some of the plurality of entities may be separately disposed in other components. have. According to various embodiments, one or more components or operations among the above-described corresponding components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (eg, a module or a program) may be integrated into one component. In this case, the integrated component may perform one or more functions of each component of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. . According to various embodiments, operations performed by a module, program, or other component are executed sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations are executed in a different order, or omitted. or one or more other operations may be added. In this document, the term user may refer to a person who uses an electronic device or a device (eg, an artificial intelligence electronic device) using the electronic device.

Fig. 1 schematically shows an aerial image display device according to an exemplary embodiment. The display device 10 comprises at least one light propagation module 2 , at least one positive lens 3 and a projection system 4 for forming an image. The positive lens 3 may represent a lens having positive refractive power.

The at least one light propagation module 2 may include a first transmission grating A, a second transmission grating B, at least one waveguide D, and a reflection grating C. Each of the at least one positive lens 3 may be arranged to cover each of the at least one light propagation module 2 . Hereinafter, the first transmission grating (A), the second transmission grating (B), and the reflection grating (C) may be referred to as at least one diffraction grating.

The display apparatus 10 according to an exemplary embodiment may display an aerial image in free space so that it can be viewed with the naked eye at a specific angle of view (FoV) at a location somewhat distant from the aerial image. Exemplary embodiments may be implemented through a combination of a waveguide, a diffractive optical element (DOE), a monocentric projection optics, and a focusing lens arrangement. The display device 10 according to the exemplary embodiment has a compact size, and may display an enlarged image compared to an image provided by a projection system, and the displayed image may be located in space and provide an enlarged view of an aerial image. . The image may be magnified by a factor of or equal to the ratio of the focal length of the lens of the projection system to the focal length of the focal lens forming the image. While the display device 10 has a high picture quality and has a positive image offset, there are no moving structural elements and there is no need to provide an additional scattering medium for display.

As used herein, the term “aerial image” may mean that the image is at some distance from the aerial imaging device. In other words, an image can be positioned between the display aperture and the viewer, and the viewer can view this image from the air. If a scattering medium, for example a diffusing film, is placed in the image plane, the reproduced aerial image will be clearly visible on the diffusing film.

The term “positive offset” of an image may mean that the aerial image is located between the forming decoupling aperture of the aerial image display device and the viewer.

The enlarged field of view of an aerial image means that the aerial image can be viewed within a wide viewing angle. That is, since the image can only be viewed within the aperture of the aerial image display device, the larger the display aperture, the larger the viewing angle of the aerial image will be.

The display device according to an exemplary embodiment does not require an additional scattering medium to display an image in free space. In addition, the display device according to the exemplary embodiment can be used in various types of small devices with a display, such as a smart phone or a smart watch, and for example, when operating with virtual assistants, the display device in the TV presentation - Can also be used on non-compact display devices.

In a display device according to an exemplary embodiment, a diffractive multi-directional radiation waveguide D may be used, and light may be in-coupled into the waveguide at the center of the waveguide D_. A small aperture can be increased in all directions to fill the entire aperture of the radiation waveguide D. The diffractive multi-directional radiation waveguide D includes a diffraction grating, so that the aerial image display device can have a compact size .

1 , the positive lens 3 may be divided into, for example, a plurality of sectors 3a, and the plurality of sectors 3a may be arranged in a circular array form. A diffractive multi-directional radiation waveguide D is integrated with positive lenses 3 in a circular array, each positive lens sector 3a has a respective angle of view, and the angle of view of each positive lens sector 3a is adjacent It may be connected to the angle of view of the positive lens sector 3a. Thus, users can view aerial images within an azimuth of up to 360 degrees.

The display device 10 may include at least one light propagation module 2 . Each of the at least one light propagation module 2 may include at least three diffraction gratings and a waveguide D. At least three diffraction gratings are stacked to form a stack, and can function in-coupling and out-coupling of light. The at least three diffraction gratings may include a first transmission grating (A), a second transmission grating (B), and a reflection grating (C). The first transmission grating A, the second transmission grating B, and the reflection grating C may form a stack of diffraction gratings. The waveguide D is an optical transmission element based on total internal reflection, and may be, for example, a diffractive multi-directional radiation waveguide. A waveguide D may be arranged to contact one of a first transmission grating A, a second transmission grating B, and a reflection grating C.

Each of the at least one positive lens 3 may be arranged to cover the light propagation module 2 . The positive lens 3 and the light multiplication module 2 corresponding thereto may constitute the image forming module 1 .

The projection system 4 may be arranged to provide an image at the same angle to each of the at least one image forming module 1 . When the projection system 4 provides an image at the same angle for each image forming module 1 , the aerial image formed by each image forming module 1 is lined up in free space in the form of a uniform ring. ) can be In the case of providing images from different angles, the formed aerial images can create any shape of irregular shape. In the case of a uniform ring, users can see the aerial image smoothly transmitted from the sector of the aerial image forming module 1 . However, if the aerial images provide images at different angles, a phenomenon in which the aerial images jump as they move between sectors may occur.

However, there may be cases where the projection system 4 is required so that the image forming module 1 provides images from different angles. Thus, the projection system 4 can supply an image to each of the at least one image forming module 1 .

The optical transmission waveguide (D) can act like a miniature telescope with a magnification of 1x. That is, light incident on the waveguide D may exit from the waveguide D at the same angle as the angle incident on the waveguide D, and the first transmission grating A, the second transmission grating B, and reflection Due to the diffraction in the grating C and multiple reflections in the waveguide D, the optical aperture at the output of the display device may be larger than the optical aperture at the input of the display device.

A small-sized image is input to the aerial image display device, and the original image can be multiplied through multiple reflections by the first transmission grating (A), the second transmission grating (B), and the reflection grating (C).

An aerial image may be formed near the focal plane of the positive lens 3, and the aerial image may be enlarged compared to the original image. This is because the focal length of the positive lens 3 is several times greater than the focal length of the lens of the projection system 4 .

Due to the total reflection operation of the waveguide D, the aerial image display apparatus can have a compact dimension and provide an aerial image of an enlarged angle of view.

Since at least one positive lens 3 is used for light outcoupling, an aerial image can be formed in the image plane of the positive lens 3 , ie at a certain distance from the positive lens 3 , with an angle of view of up to 360 degrees may increase, the image quality may be improved, and the overall dimension of the image may be reduced. Here, as in the general case, azimuth can be understood as the angle measured between a direction to an object (in this case an image) and a direction to a given object. For example, if North is a 0 degree azimuth, East may be a 90 degree azimuth, South may be a 180 degree azimuth, West may be a 270 degree azimuth, and a 360 degree azimuth may represent a full clockwise rotation of the image.

The total internal reflection (TIR) based waveguide D may be a radial waveguide. The first transmission grating (A), the second transmission grating (B), and the reflection grating (C) are either a volume holographic (Breg) grating recorded on a film and deposited on the surface of the waveguide (D) or of the waveguide (D). It may be a relief diffraction element formed on the surface.

The waveguide D may be made of a transmission optical material that is transparent in the visible range spectrum. The material may be, but is not limited to, glass, polymer, or photonic crystal that is transparent in the visible range spectrum.

2 is a cross-sectional view of an aerial image display device; The light propagation module 2 may be radial. That is, the light multiplication module 2 can implement an all-round multiplication of the decoupling aperture of the projection system 4 . In an exemplary embodiment, the waveguide D may be disposed between the reflection grating D and the two transmission gratings A and B. The projection system 4 can be arranged in the center of the light propagation module 2 .

3 shows the operation of an aerial image display device, ie propagation of a beam within the device and formation of an aerial image. The shape process of aerial images will be described in more detail. Referring to FIG. 3 , a projection system 4 may be provided between the positive lens 3 and the first transmission grating A .

<Stage 1>

A beam from the projection system 4 corresponding to the image "at infinity", ie each point of the image, can be obtained by means of one of the parallel beams falling on the first transmission grating A. Here, the following physical effects may occur. Light from the projection system 4 propagates through the first transmission grating A and the second transmission grating B into the waveguide D, where the refraction of the light at the air/material interface of the first transmission grating A is and diffraction may occur in the first transmission grating A. In practice, it is impossible to achieve 100% efficiency of the diffraction grating, and the beam can be split into two beams: a 1st-order diffracted beam (a) and an undiffracted 0th-order diffracted beam. The direction of the diffraction beam may be determined by the orientation of the first transmission grating A. For example, it is assumed that the vector of the first transmission grating A is +120 degrees with respect to the horizontal axis.

<Stage 2>

The zero-order beam of the first transmission grating A reaches the interface between the medium of the first transmission grating A and the second transmission grating B, the light is refracted at the interface between the medium, and the refracted beam is It may be diffracted in the second transmission grating (B). In this case, two beams of the first diffracted beam b and the non-diffracted zero-order beam may be formed. The direction of the diffraction beam may be determined by the orientation of the second transmission grating B. For example, suppose the grid vector is -120 degrees with respect to the horizontal axis.

After the second transmission grating B, the 1st diffracted beam a) (b) and the 0th diffracted beam arrive at the interface between the second transmission grating B and the medium of the waveguide D, and at this interface light refraction occurs.

<Stage 2.1>

The zero-order diffracted beam, which does not undergo diffraction, may pass through the waveguide D to the reflective grating C with refraction (stage 2.1 in FIG. 3 ). The first-order diffracted beam (a) (b) is in-coupled to the waveguide (D), the beam having an angle of incidence greater than or equal to a critical angle is interposed between the two boundaries of the medium, i.e. air/first transmission grating (A)/waveguide (D)/reflected at the boundary between the reflective grating (C). The critical angle may be determined in consideration of refractive indices of materials of the reflection grating C and the waveguide D. The beams propagate through the waveguide (D) as they multiplely pass through the first transmission grating (A), the second transmission grating (B). These beams are shown inside the waveguide D propagating to the right. As a result, the first-order diffracted beam a from the first transmission grating A forms the first-order diffracted beam c from the second transmission grating B, and the 1st order diffracted beam a from the second transmission grating B The first-order diffracted beam b may form a first-order diffracted beam d from the first transmission grating A.

<Stage 3>

The first diffraction beam c and the first diffraction beam d are diffracted by the reflection grating C, pass through the waveguide D, the second transmission grating B and the first transmission grating A, and each It is outcoupled to the positive lens 3 by refraction at the media boundary. The positive lens 3 also refracts the out-coupled beam and focuses it into a focal plane to form an aerial image. The process up to this point is called cycle 1.

An undiffracted beam (0th order) arrives at a reflection grating C, which is split into a 1st diffracted beam (e) and an undiffracted beam (0th order), reflected back to the projection system 4 and the whole system It passes through refracting Then these beams are not considered. The grating vector of the reflection grating C is oriented parallel to the horizontal axis.

The 1st order diffracted beam e returns to the interface of the air/first transmission grating A and passes with refraction through the waveguide D, the second transmission grating B and the first transmission grating A. Due to total reflection from the outer surface of the first transmission grating A, these beams may be reflected back to the waveguide D.

Then, the first-order diffracted beam e falls on the first transmission grating A, and this process can be repeated again. Here, cycle 2 begins.

Without the reflection grating C, there are only three propagation directions. That is, there can be only 0, +/- 120 degree propagation directions. However, this is not enough to create a 360-degree display. So, a reflective grating (C) is required to propagate light in six directions. The six directions may be formed by adding an opposite direction to the three directions.

Thus, the beam from the projection system 4 can propagate along the waveguide D and be out-coupled.

<Stage 4>

The positive lens 3 can refract the out-coupled beam and focus the beams into a focal plane to form an aerial image between the positive lens 3 and the viewer. In this case, the positive lens 3 can form not only the aerial image but also the angle of view FoV of the aerial image. The angle of view depends on the back focal length and the aperture of the positive lens 3 .

The aerial image display apparatus may have various geometric shapes, for example, may have the shape of a sphere, a torus, a cuboid, a disk, a star, and the like.

In addition, an optical coating may be applied to the surface of the waveguide (D). For example, optical coatings include anti-reflective coatings to improve contrast/image quality, semi-reflective coatings to form images on both sides of the waveguide (D), dichroic for selective transmission of a small range of light wavelengths. filters, neutral filters, additional diffractive optical elements for changing the wavefront of light outcoupled from the waveguide D, and the like. The additional diffractive optical element may act as a lens to deflect light outcoupled from waveguide D in any direction. This coating can be applied to the side of the waveguide D without the diffractive optical element.

4A, 4B and 4C show variations of the arrangement of components of an aerial image display device.

The light propagation in the device variants shown in FIGS. 4A , 4B and 4C is similar to the light propagation in the embodiment of the device shown in FIG. 3 . The difference is that the positions of the three diffraction gratings (A, B, C) with respect to the waveguide (D) are different. The positions of the three diffraction gratings (A, B, C) can be dictated by possible uses of an aerial image display device, for example the device shown in Figure 4b can project an aerial image downward from the ceiling .

In the aerial image display device shown in Fig. 4A, the projection system 4 is positioned above the positive lens 3, and below the positive lens 3 is a waveguide D, a first transmission grating A, and a second transmission A grating (B) and a reflective grating (C) may be located in this order.

In the aerial image display device shown in FIG. 4B , the projection system 4 is located below the positive lens 3 , and above the positive lens 3 , the waveguide D, the first transmission grating A, and the second transmission A grating (B) and a reflective grating (C) may be located in this order.

In the aerial image display device shown in FIG. 4C , the projection system 4 is positioned above the positive lens 3 , and below the positive lens 3 , a first transmission grating A, a waveguide D, and a second transmission The grating (B) and the reflection grating (C) may be sequentially positioned. In this embodiment, since all surfaces of the waveguide D are connected to the first transmission grating A and the second transmission grating B, no additional coating can be applied to the waveguide D.

Referring to FIG. 5A , an aerial image display device according to another embodiment includes a first positive lens 31, a reflective grating C positioned on the first positive lens 31, and a waveguide D positioned on the reflective grating C. , a second transmission grating B located above the waveguide D, a first transmission grating A located above the second transmission grating B, a second positive lens 32 located above the first transmission grating A, a second It may include a projection system 4 positioned above the two positive lenses 32 . In this embodiment, the image I may be displayed on both sides of one side of the display device and the other side of the display device. An image can be viewed from the side of the first transmission grating A and opposite to the display device, that is, from the side of the reflection grating C. In this case, the reflection grating C may have some transmission characteristics of light. That is, the reflective grating C may transmit part of light and reflect part of light. The light may be out-coupled from both sides of the aerial image display device due to some transmission of the light by the reflective grating C.

Figure 5b shows the path of the beam by the arrangement of each element of the aerial image display device shown in Figure 5a.

<Stage 1>

The beam from the projection system 4 corresponding to “infinity” (ie each point of the image is acquired by a parallel beam) propagates to the first transmission grating A. Here, the following physical effects occur. Light may propagate from the projection system 4 through the first transmission grating A, the second transmission grating B to the waveguide D. Light is refracted at the interface between air/medium of the first transmission grating A, and diffraction of the light can occur at the first transmission grating A. The beam may be split into a primary beam (a) and a non-diffracted 0th order beam. The direction of the diffraction beam may be determined by the orientation of the first transmission grating A. For example, it is assumed that the vector of the first transmission grating A is +120 degrees with respect to the horizontal axis.

<Stage 2>

The zero-order beam exiting the first transmission grating (A) propagates to the A/B medium interface, and the light may be refracted at the medium interface and diffracted by the second transmission grating (B). In this case, two beams of a diffracted beam b and a non-diffracted zero-order beam may be formed. The direction of the diffracted beam may be determined by the direction of the second transmission grating (B). For example, it is assumed that the vector of the second transmission grating B is -120 degrees with respect to the horizontal axis.

After passing through the second transmission grating (B), the first-order diffracted beams (a) (b) and the zero-order diffracted beam arrive at the interface of the second transmission grating (B) and the waveguide (D) where light refraction occurs.

<Stage 2.1>

The non-diffracted zeroth order beam enters the reflective grating C (with refraction) through the waveguide D. The first-order diffracted beams (a) (b) are in-coupled into the waveguide (D), whereas for all angles of incidence greater than the critical angle the beam is reflected back between the boundary of the two media (total internal reflection phenomenon). The critical angle may be determined in consideration of refractive indices of materials of the reflection grating C and the waveguide D. The re-reflection is caused by multipath through air/first transmission grating (A), waveguide (D)/reflection grating (C) as well as through first transmission grating (A) and second transmission grating (B) in waveguide (D) ) can also occur in propagation along As a result, the 1st order diffracted beam a from the 1st transmission grating A forms the 1st order diffracted beam c from the 2nd transmission grating B, and 1st order diffraction beam c from the 2nd transmission grating B A first-order diffracted beam b may form a first-order diffracted beam d from the first transmission grating A.

<Stage 3>

The primary diffracted beam c and d is diffracted by the reflection grating C, and through the waveguide D, the second transmission grating B, and the first transmission grating A, the second positive lens 3b ) can be out-coupled. In this process, refraction may occur at the boundary of each medium. Also, the first-order diffracted beams c and d may be diffracted from the other side of the reflective grating C toward the first positive lens 3a to be out-coupled to the first positive lens 3a. The first positive lens 3a and the second positive lens 3b refract the out-coupled beam and focus it on the focal plane of the corresponding lens. Thereby it is possible to form two aerial images on either side of the aerial image display device. The process up to this point is called stage 3. Thereby, cycle 1 ends.

A non-diffracted zeroth-order beam propagates to a reflective grating C, and this beam can be split into a first-order diffracted beam e and a zeroth-order diffracted beam. The two split beams are reflected back to the projection system 4 and can pass through the entire device with refraction. Then, these beams are not considered. Orient the vector of the reflection grating (C) parallel to the horizontal axis.

The first-order diffracted beam e is returned back to the air/first transmission grating A interface, while these beams refract the waveguide D, the second transmission grating B and the first transmission grating A. pass while Due to total internal reflection from the outer surface of the first transmission grating A, these beams may be reflected back into the interior of the waveguide D.

Thereafter, the first-order diffracted beam e is propagated to the first transmission grating A, and this process can be repeated again. Cycle 2 is thus started.

Without the reflective grating C, there can be only three propagation directions (0, and +/- 120 degrees). This may not be enough to make a 360-degree display. Therefore, the reflective grating C can be used to propagate light in six directions. That is, the reflection grating C may add three opposite directions.

Thus, the beam from the projection system 4 can propagate along the waveguide D and be out-coupled.

<Stage 4>

The first positive lens 31 and the second positive lens 32 refract the out-coupled beam and focus on the corresponding focal plane between the first positive lens 31 and the observer, and between the second positive lens 32 and the Aerial images can be formed between observers. In this case, the first positive lens 31 and the second positive lens 32 may form an angle of view FoV as well as an aerial image. The angle of view may vary according to apertures and back focal lengths of the first positive lens 31 and the second positive lens 32 .

In the aerial image display apparatus according to an exemplary embodiment, the image formed by the projection system 4 may be displayed on the opposite side of the projection system 4 .

6A, 6B, 6C show variants of the arrangement of the components of the aerial image display device when the projection system 4 and the formed image are positioned opposite each other to the aerial image display device. In such embodiments, the first and second transmission gratings (A) (B) may be exchanged.

Referring to FIG. 6A , the reflective grating C is positioned below the second transmission grating B, the positive lens 3 is positioned under the reflective grating C, and the first transmission grating A is positioned above the second transmission grating B. ), a waveguide D may be located above the first transmission grating A, and a projection system 4 may be located above the waveguide D. In this case, the aerial image may be formed under the reflection grating c. In this example, an anti-glare coating, an anti-reflective coating, or the like may be applied to the waveguide D. Therefore, an image with improved contrast can be obtained.

Referring to FIG. 6b , the projection system 4 is positioned below the waveguide D, the first transmission grating A is positioned above the waveguide D, and the second transmission grating B is positioned above the first transmission grating A The reflective grating C may be positioned on the second transmission grating B, and the positive lens 3 may be positioned on the reflective grating C. In this case, the aerial image may be formed on the reflection grating C. In this example, an anti-glare coating, an anti-reflective coating, or the like may be applied to the waveguide D. Therefore, an image with improved contrast can be obtained. By arranging the components in this way, an aerial image can be formed over the reflection grating C.

Referring to FIG. 6C , the reflection grating C is positioned under the second transmission grating B, the waveguide D is positioned on the second transmission grating B, and the first transmission grating A is positioned on the waveguide D and a projection system 4 can be located above the first transmission grating A. In addition, the positive lens 3 may be positioned under the reflection grating C.

By arranging the components in this way, an aerial image can be formed under the reflective grating C. In this case, since the waveguide D is positioned between the first transmission grating A and the second transmission grating B, it is difficult to apply an additional coating to the waveguide D.

Since the beam path in the embodiments shown in FIGS. 6A to 6C is similar to the beam path described with reference to FIG. 5B , a detailed description thereof will be omitted.

If the first transmission grating (A), the second transmission grating (B), and the reflection grating (C) are designed such that the light beam is out-coupled at a vertical angle, the user can view the vertical image display as shown in Fig. 7a. Aerial images can only be viewed within one range.

The diffraction gratings (A) (B) (C) can be designed to be out-coupled at a specific angle. In this case, as shown in Fig. 7b, the aerial image cannot be viewed in a range perpendicular to the device. That is, the angle of view in the vertical plane can be controlled by changing the configuration of the diffraction gratings (A) (B) (C). In this case, if the smart phone is far enough away from the user, the user can still see the aerial image.

As shown in FIG. 8 , the display apparatus according to an exemplary embodiment may additionally include at least one waveguide for transmitting light. The at least one waveguide may include, for example, a first waveguide D1 and a second waveguide D2. The first waveguide D1 and the second waveguide D2 may be located close to each other. When a plurality of waveguides are provided, chromaticity of an aerial image may be improved. Each waveguide may be responsible for a color corresponding to each waveguide. For example, as shown in FIG. 8 , the first waveguide D1 is responsible for propagation of blue light BL, and the second waveguide D2 is responsible for propagation of red light R and green light G. can be responsible for

Referring to FIG. 9A , a prism P may be provided at the center of the waveguide D. A prism P may be used for in-coupling of light. A hole 6 may be provided in the waveguide D, and a prism P may be provided in the hole 6 . The first transmission grating (A), the second transmission grating (B), the reflection grating (C) may have limited diffraction efficiency, and thus the out-coupled diffraction beam of the desired order relative to the in-coupled optical power. The ratio of optical power may be limited. The prism P can provide higher efficiency compared to in-coupling light through diffraction gratings.

In addition, as shown in FIG. 9B , the light propagation module 2 of the display device may include a radial structure of a radial waveguide and a concentric ring-shaped diffraction grating. By modifying the design of the waveguide (D), the first transmission grating (A), the second transmission grating (B), and the reflection grating (C), the image aperture can be increased in all directions and the angle of view can be increased. In this embodiment, the light is directed in a radial direction from the center to fill the entire decoupling aperture of the aerial image display device.

The beam from the projection system 4 forms an angle of view in the range of 360 degrees, and the beam that has passed through the prism P is coupled to the first transmission grating A, the second transmission grating B, and the reflection grating C. Together they may be in-coupled to the waveguide D. In this case, the first transmission grating A, the second transmission grating B, and the reflection grating C may be located on one of the surfaces of the waveguide D as shown in FIGS. 6A and 6B . Diffraction and outcoupling of light from waveguide D may occur in each ring structure of waveguide D together with first transmission grating A, second transmission grating B, and reflection grating C. .

As shown in FIG. 10 , the light propagation module 2 includes a waveguide D, a first transmission grating A, a second transmission grating B, and a reflection grating C, and the light propagation module 2 ) may be covered with an array of positive lenses 3 .

When the radial disk-shaped waveguide D is used, each of the arrays of positive lenses 3 may be a truncated sector-shaped positive lens. Light from the light propagation module 2 may be incident on each positive lens 3 and focused near the focal plane of each positive lens 3 .

If the projection system 4 forms an image at infinity and there is no distortion in the waveguide D, the image can appear precisely in the focal plane of the positive lens 3 . However, since in practice the projection system 4 is not ideal and there is distortion, the image may be located near the focal plane.

Each component of the light propagation module 2 and the positive lens 3 may form an aerial image and form an angle of view of the aerial image in a portion of space determined by the focal length of the positive lens 3 . The angle of view of an aerial image can be fixed or variable for a 3D stereoscopic image and can be viewed from a specific part of the angle of view.

11A and 11B , a combination of viewing areas is possible, several images are formed instead of one aerial image, and an aerial image equal to the number of pieces of the light multiplication module 2 together with the positive lens 3 can be formed. Each aerial image has its own field of view and can be viewed according to the position of each piece. That is, when viewing the image from the perimeter of the display device, the aerial image from each corresponding piece can be displayed within the user's angle of view.

Thus, it is possible to change the azimuth of the angle of view and change the inclination of the displayed image. In the case of using the head/eye tracking system, it is possible to obtain the effect of viewing an image according to the position of the head or eyes. In addition, when a dynamic lens is used, it is possible to obtain a stereoscopic aerial image effect.

As shown in FIG. 11A , the positive lens 3 may be composed of a plurality of sector lenses. The positive lens 3 may include a first lens sector 3a, a second lens sector 3b, and a third lens sector 3c. When the positive lens 3 is divided into a plurality of sectors, the image quality may be improved by increasing the ratio of the focal length of the positive lens 3 to the diameter of the aperture.

11B shows an example in which the display device according to an exemplary embodiment is applied to the mobile phone 20 . A disk-shaped image forming module 1 is provided on the rear side of the mobile phone 20 , and the image formed by the image forming module 1 can be displayed in the air. The positive lens 3 includes a plurality of sectors, and an aerial image is respectively displayed at an angle of view corresponding to each sector of the positive lens 3 . Each user can view the aerial image produced by that lens sector in that field of view. For example, the first image I1 emitted through the first lens sector 3a of the positive lens 3 is displayed in the first viewing area, and the second image I2 emitted through the second lens sector 3b is displayed in the first viewing area. ) may be displayed in the second viewing area.

The positive lens 3 may include, for example, a Fresnel lens having a thickness in the range of 0.5 to 5 mm. The positive lens 3 may have a large aperture and a short focal length to ensure a wide field of view. The smaller the ratio of the focal length to the aperture, the worse the image quality may be. As the display aperture increases, the angle of view of the floating image may increase. Therefore, in the aerial image display device according to the exemplary embodiment, lenses having a large focal length ratio of the positive lens to the aperture, such as a Fresnel lens or a diffractive lens, may be used as the positive lens 3 . The positive lens 3 may be a dynamic lens. The dynamic lens may be, for example, a lens with a variable focal length based on liquid crystal. In this case, the aerial image display device may form a three-dimensional aerial image. A dynamic lens can only form one image at any given moment corresponding to a certain depth of the 3D image. Because the lens realignment of a dynamic lens occurs faster than the time when the eye and light are integrated, a person can perceive multiple 2D images as a single 3D image. Due to this effect, a three-dimensional image can be obtained.

If the display device has an eye tracking system or a head tracking system, the display device may adjust the volumetric image or display another image as the user moves. According to the position of the user's eyes/head, an image corresponding to the position may be displayed. Thus, a high-quality image with minimized optical aberration can be maintained. When a volumetric image is created, each user's eye/head position can be displayed as a set of images corresponding to a focal plane (3D image depth) separated for that position, and a high-quality volumetric image can be formed. can

A circular lens array may be made in the gap with the waveguide D, and the gap may be filled with a layer of optical material. This design can hide the image projection system 4 . The optical material layer between the waveguide D and the positive lens 3 may have optical properties such as transparency for a predetermined range of wavelengths and sensitivity to polarization. The optical material layer may alter the wavefront of the incident light in a particular way, which may improve the quality of the formed image.

Any suitable technique may be used for the projection system. For example, but not limited to projection systems, display systems such as static image/set/video, etc., DMD/LCoS/FLCoS/LCD/MEMS-based display systems, etc., laser/LED/lamp-based display systems, color/black and white / Arbitrary wavelength spectral system, polarized / non-polarized / partially polarized system, etc. can be used.

Positive lenses 3 include, but are not limited to, anti-reflection films (enhancing image contrast), polarizing coatings, neutral density filters, spectral filters, active/passive filter PDLC/PSLC stacks (providing light diffusion/transmission). ) and the like.

The positive lens 3 may have various shapes. For example, as shown in FIG. 12A , the positive lens 3 may be, for example, a single solid lens. One positive lens 3 may cover the light multiplication module 2 . 12B , the positive lens 3 may include a plurality of sectors, for example, a first lens sector, a second lens sector, and a third lens sector 3a, 3b, 3c. The first lens sector, the second lens sector, and the third lens sectors 3a, 3b, and 3c may constitute a circular lens array. The first lens sector, the second lens sector, and the third sectors 3a, 3b, and 3c may have an eccentric circular array structure. Referring to FIG. 12C , the positive lens 3 may include a plurality of lens sectors, for example, a first lens sector, a second lens sector, and third lens sectors 3a, 3b, and 3c. The first lens sector, the second lens sector, and the third lens sectors 3a, 3b, and 3c may constitute a circular lens array in which a hole 15 is formed in the center. The first lens sector, the second lens sector, and the third lens sectors 3a, 3b, and 3c may be symmetrically arranged around the hole 15 .

As shown in FIG. 12D , the first lens sector, the second lens sector, and the third lens sector 3a, 3b, and 3c of the positive lens 3 are asymmetrical with respect to the hole 16 , eccentrically. may be arranged in a given form. The first lens sector, the second lens sector, and the third lens sectors 3a, 3b, and 3c may have a truncated sectoral shape. Referring to FIG. 12E , the positive lens 3 may include two semicircular lens sectors. Referring to FIG. 12F , the positive lens 3 may include two lens sectors having a partially cut circular shape, and a hole 17 may be provided between the two lens sectors.

Referring to FIG. 12G , the positive lens 3 may have a structure in which a ring is divided into two sectors. Referring to FIG. 12H , the positive lens 3 may include two lens sectors in a trapezoidal shape. Referring to FIG. 12I , the positive lens 3 may include two lens sectors in a pentagonal shape. Referring to FIG. 12J , the positive lens 3 may include two lens sectors in the shape of a heart. Depending on the shape of the positive lens 3, the shape of the light propagation module may be configured correspondingly. The sectors of the positive lens 3 may have different sizes, the projection system may be eccentric rather than centered in the aerial image display device, and the light multiplication module 2 may cover a plurality of lens sectors. .

According to an exemplary embodiment, an original image may be projected using a projection system. A beam from the projection system is directed at an in-coupling aperture of the light propagation module, and light propagation may occur through multiple reflections. The enlarged or augmented aperture can then be displayed on the positive lenses, each focusing the image to the focal plane of each lens and forming its own image identical to that transmitted by the image source. In this case, when the viewing direction is shifted, the viewer can see the image formed by the lens in question.

When the display device according to an exemplary embodiment is applied to a mobile device, the image may be viewed in the background of the display aperture of the mobile device.

The aperture of the mobile device may refer to the entire display surface of the mobile device on which an image is displayed. That is, the image can only be viewed on the surface of the display of the mobile device on which the image is directly formed. In this case, the observer's eye may be positioned above the display of the mobile device to cause the beam outcoupled from the projection system to fall directly on the retina of the eye to form a real image. Thus, if the user does not see at least part of the display surface from the front, for example if the user is on the side of the display, then the beam outcoupled from the projection system will not form an image on the retina and the user will not be able to see the aerial image. .

In this case, a mobile device (smart phone) can be used to form the dynamic image. A dynamic image may refer to an image that has not been pre-recorded for use in a projection system, for example. Using a smartphone, the projection system can display images, videos, notifications, and anything else that can be displayed on the smartphone screen.

The aerial image display device according to an exemplary embodiment may be integrated anywhere on the side or back of the mobile device, and transmitting the image from the smart phone display to the projection system may be implemented using a known projection method.

The aerial image display apparatus according to the exemplary embodiment may be used without a mobile device, but in this case, a static image projection system or a device other than the mobile device may be used as an image source.

13A shows an aerial image display device using beam tracking software, for example, LightTools, and FIG. 13B shows a light transmission simulation result through a beam tracking model.

The aerial image display apparatus used in the model includes a waveguide and a plurality of diffraction gratings applied to the surface of the waveguide, a projection system including a DMD micro-projector, and a positive lens forming an aerial image. The model of the projection system in FIG. 13a includes an image source including a projection lens and a micro-display that forms a seven-point star. The image source is located at the focus of the projection lens. The size of the image source and the focus of the projection lens determine the angular distribution (hereinafter referred to as the angular field). Gray regions in the waveguide model may represent beams that are outcoupled from the projection system and pass through the waveguide and remain at its surface. The gray area represents the size of the actuating decoupling aperture of the waveguide.

This model may include several optical receivers, for example a first receiver 21 , a second receiver 22 and a third receiver 23 to control the display parameters. The signals from the first receiver 21 , the second receiver 22 and the third receiver 23 are shown in FIG. 13B . A receiver between the image source and the projection lens of the micro-projector may control the field of view and size of the image source. The receivers of the projection system monitor the angular field applied to the input of the waveguide. Receivers located between the waveguide and the positive lens control the angular field of the projection system emerging from the waveguide.

A receiver located at the focal point of the positive lens controls the shape and size of the aerial image formed by the positive lens. In FIG. 13b the images from the first receiver 21 , the second receiver 22 and the third receiver 23 are arranged in the order that light from the projection system passes through the device to display an aerial image. Thus, the beam sequentially tracked by the software passes through all elements of the apparatus, including the first receiver 21 , the second receiver 22 and the third receiver 23 located near some element of the apparatus. The first receiver 21 , the second receiver 22 , and the third receiver 23 have no physical/physical properties, and are only some planes on which light is recorded in the stage of light passing through the device. The difference in the signal at each receiver is conditioned by the loss of the beam during the absorption/scattering process along the path of the beam.

The sprocket R on the second receiver 22 is inverted relative to the sprocket R on the first receiver 21 as the projection lens flips the image away from the image source. As the beam passes through the system further, the original signal is degraded, resulting in a less sharp and less bright image at the subsequent receiver.

14 is a vector diagram of diffraction gratings illustrating the function of the diffraction gratings (first transmission grating, second transmission grating, reflection grating) as well as the direction of propagation of the angular distribution (hereinafter referred to as the angular field) of the projection system; show The function of the diffraction gratings may include in-coupling, multiplying, out-coupling, etc. of the diffraction gratings when the angular field of the projector is diffracted in one direction or the other due to the omni-directional field propagation of the projection system.

The rings shown in Figure 14 represent the limitations imposed on the diffraction grating waveguide. The inner ring limits the angular field of the projection system that can propagate along the waveguide due to total internal reflection. The outer ring limits the angular field of the projection system that can pass through the waveguide by the selectivity of the diffraction gratings. That is, the outer ring restricts diffracting only light incident on the diffraction grating at a specific angle (selection condition).

The rectangle represents the angular field of the projection system that will pass through the waveguide. The arrow indicates the vector of the diffraction grating, that is, the direction in which the incident light is diffracted.

The problem of calculating a waveguide system based on the diffraction grating can be reduced in determining the distance of the vectors of the diffraction grating so that the total internal reflection condition and selectivity are satisfied. In addition, computational problems can be reduced in determining the vector direction of the diffraction grating to ensure propagation of the angular field of the projection system in the required direction. By synthesizing the angle field of the first transmission grating and the angle field of the second transmission grating, an angle field converted for a multi-directional extended beam aperture can be obtained.

An aerial image display device according to an exemplary embodiment may be miniaturized enough to be used with mobile devices as well as formation of aerial images. In addition, exemplary embodiments may display aerial images within large viewing angles to visualize the images without the need to use auxiliary effects such as additional diffusion media, plasmas, and the like. In addition, all elements of the display device according to the exemplary embodiment are fixed and there are no moving elements.

The aerial image display device according to an exemplary embodiment may be used not only to display images, but also to create a holographic user interface when interacting with home appliances such as refrigerators, hobs, TVs, air conditioners, air conditioners, intercoms, and the like. In addition, the aerial image display device according to the exemplary embodiment can be used in hazardous industries. That is, the control element can appear to be flying in the air. In this case, an additional camera can be used to detect explicit interactions that can be expressed, for example, by user gestures. The gesture may be symbolic, such as a thumbs-up, for example, directive, such as a pointing gesture, an icon gesture that reproduces a specific movement, or a pantomimic gesture using an invisible tool.

Additionally, additional cameras can be used to detect implicit interactions. In this case, proxemics can be understood as a system of symbols in which space and time of the composition of a communication process have a semantic load. For example, when two users who have a mobile device including an aerial image display device according to an exemplary embodiment use the display device, since the display device can project a moving image, the hologram of the talker is the communication time and context can be changed. In this case, this may be referred to as a hologram and may not be the same as the user's body size. At the same time, the modification of the volumetric image can also occur by the user's participation (using gestures, press buttons, voice control, user eye movement, etc.) This can happen without the user's participation. In this case, for example, if the user uses a display device having an additional sensor for the position and reaction of the user's body, the communication between the talker holograms can occur without active motion by a part of the user.

Interactions between devices can occur, such as in the Internet of Things. Several small devices can be used to add context-sensitive functionality to interact with the generated floating image. For example, this device-to-device interaction can serve as a temporary space to transfer information from one hologram to another.

While some exemplary embodiments have been described, it should be understood that the spirit of the present invention is not limited to these specific embodiments. On the contrary, the spirit of the invention includes all alternatives, modifications and equivalents that may be included within the spirit and scope of the claims. Furthermore, the present invention retains all equivalents of the claimed invention, even if the claims are modified in the course of consideration.

1: Image forming module
2: Light propagation module
3: positive lens
4: Projection system
A: first transmission grid
B: second transmission grating
C: reflective grating
D: waveguide

Claims (33)

An aerial image display device comprising:
projection system;
at least one positive lens;
at least one light propagation module,
the at least one light propagation module includes a first transmission grating, a second transmission grating, at least one waveguide, and a reflection grating;
Each of the at least one positive lens is arranged to cover each of the at least one light propagation module. According to claim 1,
The projection system is located above the at least one positive lens, the positive lens is located above the waveguide of the at least one optical propagation module, and the first transmission grating, the reflection grating, and the second transmission grating are below the waveguide in this order. As laid out, the display device. According to claim 1,
wherein the projection system is located below the at least one positive lens, the at least one positive lens is located below the waveguide, and a first transmission grating, a second transmission grating, and a reflection grating are disposed above the waveguide in this order. According to claim 1,
wherein the projection system is positioned over at least one positive lens positioned over a first transmission grating of the at least one light propagation module, a waveguide positioned below the first transmission grating, and a second transmission grating and a reflection grating positioned below the waveguide. , display device. According to claim 1,
the at least one positive lens is located under the reflection grating of the at least one light propagation module, and the first transmission grating, the second transmission grating and the waveguide are located on the reflection grating;
wherein the at least one light propagation module is located below the projection system. According to claim 1,
the at least one positive lens is positioned on the reflective grating of the at least one light propagation module, and the second transmission grating, the first transmission grating and the waveguide are sequentially disposed under the reflective grating,
wherein the projection system is located below the at least one light propagation module. According to claim 1,
The at least one positive lens is positioned under the reflective grating of the at least one light propagation module, and a second transmission grating, a waveguide, and a first transmission grating are sequentially positioned on the reflective grating,
and the projection system is located above the at least one light propagation module. According to claim 1,
wherein each of the at least one waveguide consists of a sector of a total internal reflection based optical transmission diffraction multidirectional radial waveguide. 9. The method of claim 8,
The display device of claim 1, wherein the light propagation module further includes a prism for light in-coupling. 9. The method of claim 8,
wherein the first transmission grating, the second transmission grating and the reflection grating are volume holographic gratings recorded on a film and deposited on the surface of the waveguide or a relief diffraction element formed on the surface of the waveguide. 11. The method of claim 10,
and each of the at least one optical propagation module has the shape of one disk sector, and the at least one optical propagation module is configured to have a disk shape as a whole. 12. The method of claim 11,
each of the at least one positive lens has the shape of one disk sector, the radius of the disk sector coincides with the radius of the corresponding light propagating module, the light multiplying module being covered by the corresponding positive lens. . 13. The method of claim 12,
A display device in which the at least one positive lens is gathered to form a circular lens array. The method of claim 1,
and each of the at least one positive lens is configured to cover a corresponding light propagating module with a gap. 15. The method of claim 14,
wherein the gap is filled with a layer of optical material. The method of claim 1,
Each of the at least one positive lens has a shape matching the shape of the corresponding light propagation module, the display device. 17. The method of claim 16,
The at least one positive lens has one of a truncated circular sector shape, a polygonal shape, and a circular shape. The method of claim 1,
wherein the waveguide is formed of a material that is transparent to a spectrum in the visible light region. The method of claim 1,
and the at least one light propagation module is configured to perform radial propagation of a decoupling aperture of the projection system. 9. The method of claim 8,
A display device, wherein one of an anti-reflective coating, a semi-reflective coating, a dichroic filter, a neutral filter, and a diffractive optical element is provided on a surface of the waveguide. The method of claim 1,
and each of the at least one light propagation module is configured to propagate light of a particular at least one color. According to claim 1,
The at least one waveguide has a shape of one of a sphere, a torus, a rectangular parallelepiped, a disk, and a star. The method of claim 1,
wherein the at least one positive lens is one of a Fresnel lens or a dynamic lens. A method of operating an aerial image display device according to claim 1, comprising:
an image forming beam from the projection system is transmitted to a first transmission grating, and as a result of diffraction, the beams are split into 1st order diffracted beams (a) and 0th order diffracted beams;
the 0th order diffracted beams are transmitted to a second transmission grating, and as a result of the diffraction the beams are split into a 1st order diffracted beam (b) and a 0th order diffracted beam;
transmitting the first-order diffracted beam (a), the first-order diffracted beam (b), and the zero-order diffracted beam to a waveguide;
The first-order diffracted beam (a) transmitted to the waveguide at an angle corresponding to the total internal reflection angle range, the first-order diffracted beam (b) is re-evaluated at the media boundary between the air/first transmission grating and between the waveguide/reflection grating. reflected and propagated along the waveguide, forming a first order diffracted beam c from a second transmission grating as a result of diffraction of the first order diffracted beam a, wherein the first diffracted beam b forming a first order diffracted beam (d) from the grating;
the first diffracted beam (c) and the first diffracted beam (d) being diffracted by a reflection grating and out-coupled to the positive lens through the waveguide, a second transmission grating and a first transmission grating; and
refracting the out-coupled beam by the positive lens and focusing the aerial image to a focal plane. 25. The method of claim 24,
wherein the 0th order diffracted beam passes through a waveguide over the reflective grating, the beams are split into a 1st order diffracted beam (e) and a 0th order diffracted beam, then the 0th order diffracted beam is not considered. 25. The method of claim 24,
the first diffracted beam (e) passes through a waveguide, a second transmission grating and a first transmission grating, and due to total internal reflection from a surface of the first transmission grating, the beams are reflected back into the waveguide;
wherein the 1st order diffracted beam (e) is transmitted to a first transmission grating, and as a result of diffraction the beams are split into the 1st order diffracted beam (a) and a 0th order diffracted beam (b). 25. The method of claim 24,
wherein the light propagation module is configured such that an aerial image is only visible within a range perpendicular to the display device. 25. The method of claim 24,
wherein the light propagation module is configured such that the aerial image display device is visible in both a range perpendicular to the aerial image display device and a range off-perpendicular to the aerial image display device. An aerial image display device comprising:
reflective grating;
a first positive lens positioned below the reflective grating;
a waveguide provided on the reflective grating;
a second transmission grating provided over the waveguide;
a first transmission grating provided on the second transmission grating;
a second positive lens provided on the first transmission grating; and
A display device, including; a projection system provided on the second positive lens. The method of operating the aerial image display device according to claim 29,
A) a beam forming an image from the projection system is transmitted to a first transmission grating, and as a result of diffraction, the beams are split into 1st order diffracted beams (a) and 0th order diffracted beams;
B) the 0th order diffracted beams are transmitted to a second transmission grating, and as a result of the diffraction the beams are split into a 1st order diffracted beam (b) and a 0th order diffracted beam;
C) transmitting the first-order diffracted beam (a), the first-order diffracted beam (b), and the zero-order diffracted beam to a waveguide;
D) the first-order diffracted beam (a) transmitted to the waveguide at an angle corresponding to the total internal reflection angle range, the first-order diffracted beam (b) is the media boundary between the air/first transmission grating and the waveguide/reflection grating is reflected back from and propagates along the waveguide, forming a first-order diffracted beam c from the second transmission grating as a result of diffraction of the first-order diffracted beam a, and the first-order diffracted beam b forming a first order diffracted beam (d) from the grating;
E) the 1st order diffracted beam (c) and 1st order diffracted beam (d) are diffracted in a reflection grating and out-coupled to a second positive lens through a waveguide, a second transmission grating and a first transmission grating;
F) the first positive lens focuses the beam outcoupled to its focal plane by forming a first aerial image, and the second positive lens focuses the beam outcoupled to its focal plane by forming a second aerial image A method comprising; focusing on 31. The method of claim 30,
the 0th order diffracted beam passes through a waveguide over the reflective grating, the beams are split into a 1st order diffracted beam (e) and a 0th order diffracted beam, then the 0th order diffracted beam is not considered. 31. The method of claim 30,
the first diffracted beam e passes through a waveguide, a second transmission grating and a first transmission grating, and due to total internal reflection from the outer surface of the first transmission grating, these beams are reflected back into the waveguide,
The first-order diffracted beam (e) is transmitted to a first transmission grating, and as a result of diffraction the beams are split into a first-order diffracted beam (a) and a zero-order diffracted beam (b), and then in step (B) - (I) step is repeated. 30. In the smart phone comprising the display device according to any one of claims 1 and 29,
wherein the projection system is configured to project information from a display of the smartphone.

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