Patent Description:
A head-up display (HUD) system may generate a virtual image in front of a driver and display information in the virtual image, thereby providing the user with a variety of information. The information provided to the driver may include, for example, navigation information and dashboard information such as a vehicle speed, a fuel level, and an engine revolution per minute (RPM). The driver may more easily recognize the information displayed in front without turning his or her gaze during driving, and thus, driving safety may improve. In addition to the navigation information and the dashboard information, the HUD system may also provide the driver with, for example, a lane indicator, a construction indicator, an accident indicator, and a pedestrian detection indicator using augmented reality (AR), to assist with driving when a view is not so clear.

<CIT> discloses a device for generating three-dimensional images and associated head-up display. This technique relates to a device for generating images, comprising a diffuser, and a scanning unit designed to generate a light beam scanning a face of the diffuser. The image generating device also comprises an autostereoscopic filter.

<CIT> relates to a video display device. The video display device includes a laser beam generator for emitting laser beams, a light deflector for deflecting the emitted laser beams, a light scattering screen for converting the light incident from the light deflector into scattered light and radiating the same, a deflector controller for controlling the light deflector and deflecting the laser beams incident on the light deflector so as to scan the whole area of a display surface of the light scattering screen, and a laser generator controller for controlling the laser beam generator and sequentially generating the laser beams to be projected onto pixels on the light scattering screen according to video to be projected onto the light scattering screen.

<CIT> refers to an embedded relay lens for head-up displays or the like. An optical relay comprises a partially-reflective-coated Fresnel lens or similar low-profile lens such as a diffractive lens or a holographic lens having a first index of refraction and a filler medium having a second index of refraction and being disposed adjacent to the Fresnel lens. The optical relay enables the optical power of the Fresnel or similar low-profile lens embedded within the two layers to influence a beam that is reflected from the optical relay while allowing transmitted light to experience little or no influence from the embedded lens.

<CIT> refers to an apparatus and method for manufacturing a holographic optical element. The apparatus includes a light irradiation part, a beam splitter for splitting the laser beam from the light irradiator into a signal beam and a reference beam, a reference beam optical system for irradiating a reference beam to a holographic recording medium, a lens array including a plurality of elemental lenses, and a signal beam optical system for irradiating the signal beam to the lens array.

It is the object of the present invention to provide an improved three-dimensional, 3D, display apparatus, 3D display method, and a computer-readable storage medium having instructions to cause a processor to perform a 3D display method.

One or more example embodiments may address at least the above problems and/or disadvantages and other disadvantages not described above. Also, the example embodiments are not required to overcome the disadvantages described above, and an example embodiment may not overcome any of the problems described above.

According to an aspect of the present invention, there is provided a three-dimensional, 3D, display apparatus comprising: an optical layer forming a lens array; an immersion layer applied to the optical layer, the immersion layer and the optical layer having a same refractive index; an optical coating being an optical coating of the immersion layer or an optical coating layer coated on the lens array, wherein the optical coating has a transmittance which changes based on a wavelength of the visible light; a projector configured to scan a light onto the optical layer; and a processor configured to control a timing at which the projector scans the light onto the optical layer and generate a 3D image in a viewing space based on the timing at which the light is scanned onto the optical layer, the 3D image being a multiview image providing different images corresponding to two different viewpoints to a left eye and a right eye of a user, or an integral image forming multiple viewing zones by integrating elemental images including 3D information of a target object.

The processor may be further configured to generate the 3D image based on virtual scanned pixels implemented by the light scanned according to the timing.

The processor may be further configured to generate the 3D image by controlling a color of the light based on the timing at which the light is scanned onto the optical layer.

The processor may be further configured to generate the 3D image by controlling a plurality of light sources generating the light based on a value of a scanned pixel corresponding to the timing at which the light is scanned onto the optical layer.

The processor may be further configured to generate the 3D image based on a direction of the light according to a corresponding positional relationship between the plurality of optical elements and the virtual scanned pixels.

The optical layer may be further configured to refract or reflect a light of a first wavelength, and transmit a light of a second wavelength different from the first wavelength.

An optical parameter of the optical layer may be determined based on a position of the projector and a position of the viewing space.

The optical layer may be provided on or inside a windshield of a vehicle.

The optical layer may comprise a holographic optical element (HOE) lens array.

The HOE lens array may be recorded to provide the 3D image in the viewing space based on a position of the projector and a position of the viewing space.

The optical layer may comprise a lens array coated with an optical coating layer having a transmittance which changes based on a wavelength of a visible light.

The projector comprises at least one laser scanning module configured to scan a laser beam onto the optical layer.

The at least one laser scanning module may comprise: a plurality of laser light sources configured to output laser beams corresponding to a plurality of colors; a beam combiner configured to synthesize outputs of the plurality of laser light sources into a single integrated beam; and a scanning mirror configured to control a direction of the single integrated beam to scan the single integrated beam onto the optical layer.

The 3D image may comprise an integral image forming multiple viewing zones by integrating elemental images including 3D information of a target object.

The 3D display apparatus further comprises according to the claimed invention: an immersion layer provided on the optical layer, wherein the immersion layer and the optical layer have a same refractive index.

The 3D display apparatus may further comprise: a compensating lens provided between the projector and the optical layer, wherein the compensating lens is configured to correct an image distortion.

According to another aspect of the present invention, there is provided a three-dimensional, 3D, display method of operating 3D display apparatus having an immersion layer applied to the optical layer, the immersion layer and the optical layer having a same refractive index, and an optical coating being an optical coating of the immersion layer or an optical coating layer coated on the lens array, wherein the optical coating has a transmittance which changes based on a wavelength of the visible light, the method comprising: obtaining information related to a timing at which a light is scanned by a projector onto an optical layer; controlling the timing at which the projector scans the light onto the optical layer; and generating a 3D image in a viewing space based on the timing at which the light is scanned onto the optical layer, the 3D image being a multiview image providing different images corresponding to two different viewpoints to a left eye and a right eye of a user, or an integral image forming multiple viewing zones by integrating elemental images including 3D information of a target object.

The 3D image may be generated based on virtual scanned pixels implemented by the light scanned according to the timing.

The generating the 3D image may comprise controlling a color of the light based on the timing at which the light is scanned onto the optical layer.

The generating the 3D image may comprise controlling a plurality of light sources generating the light based on a value of a scanned pixel corresponding to the timing at which the light is scanned onto the optical layer.

The 3D image may be generated based on a direction of the light according to a corresponding positional relationship between a plurality of optical elements included in the optical layer and the virtual scanned pixels.

The optical layer may be configured to refract or reflect a light of a first wavelength, and transmit a light of a second wavelength different from the first wavelength.

The projector may comprise at least one laser scanning module configured to scan a laser beam onto the optical layer.

The laser scanning module may comprise: a plurality of laser light sources configured to output laser beams corresponding to a plurality of colors; a beam combiner configured to synthesize outputs of the plurality of laser light sources into a single integrated beam; and a scanning mirror configured to control a direction of the integrated beam to scan the integrated beam onto the optical layer.

The computer-readable storage medium may further comprise controlling the projector, by a scanning mirror, a direction of the light; outputting, by a laser scanning module, the light through the scanning mirror, and scanning, by the laser scanning module, the light in a vertical direction or a horizontal direction.

The computer-readable storage medium may further comprise the optical layer includes a first optical element configured to refract or reflect a light of a first wavelength, and transmit a light of a second wavelength different from the first wavelength; and a second optical element configured to refract or reflect the light of the second wavelength, and transmit the light of the first wavelength.

The above and/or other aspects will be more apparent by describing certain example embodiments with reference to the accompanying drawings, in which:.

Reference will now be made in detail to example embodiments, which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Example embodiments are described below in order to explain the disclosure by referring to the figures.

The following structural or functional descriptions are to merely describe the example embodiments, and the scope of the example embodiments is not limited to the descriptions provided in the disclosure. Various changes and modifications can be made to one or more of the example embodiments by those of ordinary skill in the art.

Although terms of "first" or "second" are used to explain various components, the components are not limited to the terms. These terms should be used only to distinguish one component from another component. For example, a "first" component may be referred to as a "second" component, or similarly, and the "second" component may be referred to as the "first" component within the scope of the right according to the concept of the disclosure.

In addition, it should be noted that if it is described in the disclosure that one component is "directly connected" or "directly joined" to another component, still other component may not be present therebetween. Likewise, expressions, for example, "between" and "immediately between" and "adjacent to" and "immediately adjacent to" may also be construed as described in the foregoing.

As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be further understood that the terms "comprises" and/or "comprising," when used in this disclosure, specify the presence of stated features, integers, steps, operations, elements, components or a combination thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined herein, all terms used herein including technical or scientific terms have the same meanings as those generally understood by one of ordinary skill in the art. Terms defined in dictionaries generally used should be construed to have meanings matching with contextual meanings in the related art and are not to be construed as an ideal or excessively formal meaning unless otherwise defined herein.

<FIG> illustrates a three-dimensional (3D) display apparatus according to an embodiment of the present invention.

Referring to <FIG>, a configuration of a 3D display apparatus <NUM> is illustrated.

The 3D display apparatus <NUM> is an apparatus which implements a 3D image <NUM>, and implements the 3D image <NUM> by providing different images to a left eye and a right eye of a user. A binocular disparity may cause the user to experience 3D effects.

In general, a panel and a disparity separating device may be needed to implement a 3D image. For example, the 3D display apparatus may provide a 3D image by disposing the disparity separating device, for example, a parallax barrier or a lenticular lens, on a front surface of the panel and disposing appropriate view images on pixels of the panel. The lenticular lens may control a direction of a beam propagated to a 3D space using a characteristic of a light being refracted when passing through the lens, and the parallax barrier may control a direction of a beam propagated to a 3D space by selectively transmitting a light using a slit.

The 3D display apparatus <NUM> generates the 3D image <NUM> using a method of scanning a light to an optical layer <NUM> without using a display panel. <FIG> illustrates a head-up display (HUD) system using the 3D display apparatus <NUM>, as an example. Hereinafter, for ease of description, an example of the HUD system will be described. However, example embodiments of the 3D display apparatus <NUM> are not limited to the HUD system, and may be applied to all kinds of display apparatuses such as a TV, a digital information display (DID), a monitor, and a mobile device in various manners.

The 3D display apparatus <NUM> includes a projector <NUM> and the optical layer <NUM>. The projector <NUM> scans a light to the optical layer <NUM>. The optical layer <NUM> may include a plurality of optical elements. An optical element may be a smallest unit to generate a multiview image. Lights output from the optical elements may be gathered at a pitch in a viewing space. According to an example embodiment, the pitch may be a predetermined pitch. The optical elements may also be referred to as 3D pixels. A 3D pixel may refract or reflect only a light of a particular wavelength, and transmit a light of a wavelength other than the particular wavelength. According to an example embodiment, the particular wavelength may be a predetermined wavelength. According to an embodiment, the specific wavelength may be a range of wavelengths.

To refract or reflect only a light of a predetermined wavelength and transmit a light of a wavelength other than the predetermined wavelength, the optical layer <NUM> may include a lens array coated with an optical coating layer having a transmittance which changes based on a wavelength of a visible light. For example, dichroic mirror coating which selectively increases a reflectance with respect to a predetermined wavelength and increases a transmittance with respect to the other wavelengths may be applied to a surface of a lens array of a general optical lens.

Parameters of the optical layer <NUM> may be determined based on a position of the projector and a position of the predetermined viewing space. For example, refractive indices of the optical elements included in the optical layer <NUM> may be determined based on a position of the projector and a position of the predetermined viewing space. A method of determining the parameters of the optical layer <NUM> will be described in detail below with reference to <FIG> according to an example embodiment.

The projector <NUM> may scan a light of a predetermined wavelength to the optical layer <NUM>. A single 3D pixel to which the light is scanned by the projector <NUM> may output a light in a designed direction. According to an embodiment, the light may be scanned by the projector <NUM> for a predetermined time. Lights output from the 3D pixels may form a view image. The 3D display apparatus <NUM> may represent 3D spatial points using the plurality of 3D pixels.

The 3D display apparatus <NUM> may render an image to be generated on the optical layer <NUM>. Here, "rendering" may be an operation of determining or generating two-dimensional (2D) images to be displayed on the optical layer <NUM> to provide the 3D image <NUM> to the user. For example, "rendering" may be an operation of generating the 2D images to be displayed on the optical layer <NUM> attached to an inner surface of a windshield <NUM>, a front window of a vehicle, or inserted into the windshield <NUM> to provide the 3D image <NUM> in a particular viewing space of the user. The particular viewing space may be a predetermined viewing space of the user. Image information may be data related to an image generated on the optical layer <NUM>. For example, the image information may include data related to a size and a color of the image generated on the optical layer <NUM>.

According to an example embodiment, the "rendering" operation may be performed by a processor included in the 3D display apparatus <NUM>. Here, the processor may be implemented by hardware modules, software modules, or various combinations thereof. The processor may control the image information based on a timing at which the light is scanned to the optical layer to provide the 3D image in the predetermined viewing space. The predetermined viewing space may refer to a space in which the user may continuously observe the 3D image at positions of the eyes of the user or positions in vicinity of the eyes, even when the user moves from side to side.

The 3D image <NUM> may include a multiview image and an integral image. For example, multiview imaging may implement a 3D image by providing images corresponding to two different viewpoints among a plurality of viewpoints to both eyes of the user. For example, the user may view an image corresponding to a first viewpoint with the left eye and view an image corresponding to a second viewpoint with the right eye, thereby experiencing 3D effects from a corresponding 3D image. Integral imaging may implement a 3D image by storing 3D information of a target object in a form of elemental images using a lens array including a plurality of elemental lenses and integrating the elemental images stored through the lens array. Integral imaging will be described further below with reference to <FIG>.

<FIG> illustrates a distribution of beams output from a 3D display apparatus according to an embodiment.

Referring to <FIG>, a projector scans a light to an optical layer <NUM>. The projector may include at least one laser scanning module <NUM> configured to scan a laser to the optical layer <NUM>. The light scanned by the projector may include a laser beam scanned by the laser scanning module <NUM>. A single laser scanning module may operate as a single projector, or at least two laser scanning modules may operate as a single projector.

The laser scanning module <NUM> may be a device configured to output a beam through a scanning mirror <NUM> capable of direction control using a reflecting mirror. The laser scanning module may output the beam after beams output respectively from a plurality of laser light sources are combined through a semi-transmissive optical device. According to an example embodiment, the plurality of laser light sources may be configured to output laser beams corresponding to a plurality of colors, For example, the plurality of laser light sources may be a red laser light source, a green laser light source, and a blue laser light source. The laser scanning module <NUM> will be described further below with reference to <FIG>.

The laser scanning module <NUM> may scan a line of a second direction, for example, a line at a time in a lateral direction, while moving a laser beam in a first direction toward the optical layer <NUM>, for example, moving down from the top, by rotating the scanning mirror <NUM>. The laser scanning module <NUM> may generate a 2D image on the optical layer <NUM> through laser beam scanning. The scanning mirror of the laser scanning module <NUM> may rotate at a predetermined interval to scan a laser beam to the optical layer <NUM>.

A plurality of beams <NUM> may be determined in a 3D space based on the 2D image represented on the optical layer <NUM>. For example, the plurality of beams generated in the 3D space may change based on image information of the 2D image displayed on the optical layer <NUM>. To output a beam of different information, for example, a different color, to a different position of the optical layer <NUM> in response to rotation of the scanning mirror, the image information and the scanning interval of the scanning mirror may be synchronized. For example, information related to a laser beam may change sequentially based on the image information and the scanning interval.

The optical layer <NUM> may include a plurality of optical elements <NUM> and <NUM>. Scanned pixels may be implemented by changing beams to be scanned to the plurality of optical elements based on a timing at which a laser is scanned. The scanned pixels may not be real pixels, but virtual pixels acting as pixels implemented by laser. Laser beams may be scanned and may maintain a linear form in the optical layer <NUM>. Thus, through on-off control of the laser beams at a predetermined time interval based on the image information, separate beams to be scanned to the plurality of optical elements <NUM> and <NUM> included in the optical layer <NUM> may be generated, and the scanned pixels may be implemented by the beams. For example, a first scanned pixel corresponding to the optical element <NUM> may be implemented by a laser beam <NUM>, and a second scanned pixel corresponding to the optical element <NUM> may be implemented by the laser beam <NUM> while moving the laser beam <NUM> down from the top by rotating the scanning mirror <NUM>.

Propagation directions of beams output from optical elements may be determined based on directions of beams according to a corresponding positional relationship between the optical elements and scanned pixels, and thus 3D spatial points may be represented.

<FIG> illustrates a method of implementing scanned pixels corresponding to red, green, and blue (RGB) subpixels of a panel according to an example embodiment.

Referring to <FIG>, a 3D display apparatus may control image information by controlling a color of a light based on a timing at which the light is scanned to an optical layer.

As described above, to separate a spatial 3D image, the 3D display apparatus may dispose a disparity separating device, for example, a parallax barrier or a lenticular lens, on a front surface of a panel and may dispose appropriate view image on pixels of the panel, thereby providing a 3D image.

A general RGB panel <NUM> may have a pixel structure in which a red (R) subpixel, a green (G) subpixel, and a blue (B) subpixel are included in a single pixel. The 3D display apparatus may provide a 3D image using scanned pixels, instead of pixels of a real panel. In detail, the scanned pixels may be implemented by controlling RGB laser light sources based on image information at scanning timings corresponding to positions of the RGB subpixels.

For example, a red (R) scanned pixel may be formed by outputting only a red (R) laser beam <NUM> and not outputting, but rather blocking a green (G) laser beam <NUM> and a blue (B) laser beam <NUM> at a scanning timing corresponding to the position of the R subpixel of the RGB panel <NUM>. A green (G) scanned pixel and a blue (B) scanned pixel may be formed on the same principle based on the positions of the G subpixel and the B subpixel.

Further, by adjusting a brightness of a beam through modulation of an output laser beam of each laser light source based on the image information simultaneously with on-off control of the RGB laser light sources at a predetermined time interval based on the image information, a color of a scanned pixel may be controlled.

<FIG> illustrates a general multiview image generating method, and <FIG> illustrates a multiview image generating method according to an example embodiment. Before the multiview image generating method is described with reference to <FIG>, general multiview displaying using a panel will be described in brief with reference to <FIG>.

<FIG> shows directions in which beams output from a plurality of pixels included in a panel <NUM> are propagated to a 3D space, when a general multiview display is used to implement autostereoscopic 3D display. The beams generated from the pixels of the panel <NUM> may propagate uniformly toward a user, having a predetermined direction by a lenticular lens attached to a front surface of the panel <NUM>. When left and right images of different viewpoints are applied to pixels generating beams to be incident to left and right eyes of the user, the user may perceive a 3D image. Each pixel may include subpixels. For example, a single pixel may include RGB subpixels.

<FIG> shows directions in which beams output from scanned pixels corresponding to RGB subpixel of a panel are propagated in a 3D space using a projector, rather than using a panel <NUM>, when a 3D display apparatus according to an example embodiment is used.

The 3D display apparatus may include the projector and an optical layer. The optical layer may correspond to a lenticular lens of a general multiview-based 3D display apparatus, in that the optical layer may output a light scanned from the projector as beams including different information in many directions. Although the 3D display apparatus does not include a panel <NUM>, the 3D display apparatus may generate scanned pixels corresponding to RGB subpixels by scanning the light to the optical layer through the projector.

For example, the scanned pixels may be generated through on-off control of RGB laser light sources at a predetermined time interval based on image information at scanning timings corresponding to positions of RGB subpixels. When the light scanned from the projector is adjusted to correspond to the positions of the subpixels of the panel of <FIG>, a 3D image may be implemented in a manner similar to that of the general multiview-based 3D display apparatus.

<FIG> illustrate methods of implementing white (W) pixels using scanned pixels. In a first example <NUM> illustrated in <FIG>, a 3D display apparatus may implement W scanned pixels by controlling on-off of RGB laser light sources based on timings of scanned pixel units, and represent a gray level of a beam through modulation at the same time. In a second example <NUM> illustrated in <FIG>, the 3D display apparatus may implement W scanned pixels by controlling on-off of RGB laser light sources based on timings of subpixel units in a scanned pixel.

In another example, as shown in <FIG>, W scanned pixels may be implemented by controlling a brightness of each subpixel to be identical, without simultaneously controlling on-off of subpixels in a scanned pixel.

<FIG> illustrates a structure of a laser scanning module according to an example embodiment.

Referring to <FIG>, a laser scanning module <NUM> may include a red (R) laser light source <NUM> configured to output a red laser beam, a green (G) laser light source <NUM> configured to output a green laser beam, a blue (B) laser light source <NUM> configured to output a blue laser beam, condensers C1, C2, and C3 configured to concentrate lights output from the R, G, and B laser light sources, beam combiners <NUM> and <NUM> configured to synthesize outputs of the plurality of laser light sources into a single integrated beam, at least one reflecting mirror <NUM> configured to control a path of the beam, and a scanning mirror <NUM> configured to control a direction of the integrated beam to scan the integrated beam to an optical layer.

The beam combiners <NUM> and <NUM> may include dichroic mirrors 621a and 622a configured to reflect only lights of predetermined wavelengths generated from the R, G, and B laser light diodes and concentrated through the condensers and transmit lights of the other wavelengths. For example, the dichroic mirror 621a may have a characteristic of reflecting only a red laser beam, and the dichroic mirror 622a may have a characteristic of reflecting only a blue laser beam. A green beam may pass through the dichroic mirrors 621a and 622a, and a red beam may pass through the dichroic mirror 622a. Thus, the outputs of the RGB laser light sources may be synthesized into a single integrated beam using the dichroic mirrors 621a and 622a.

The scanning mirror <NUM> may be manufactured using micro electro mechanical system (MEMS) technology, and generate a 2D image by scanning laser beams focused on a single point to the optical layer using two driving axes. The 2D image may be implemented as a set of horizontal lines of which positions are different in a vertical direction.

The laser scanning module <NUM> may be simply structured and easily miniaturized and thus, utilized as a handheld projector. Further, by increasing a scanning angle of the scanning mirror <NUM>, a field of view may be easily increased. For example, it may be difficult in practice to mount a HUD system of a great size due to a limited space in a dashboard of a vehicle. When the HUD system is configured using the laser scanning module <NUM>, a 3D HUD image with a wide field of view may be provided to a driver.

<FIG> illustrates a method of manufacturing a holographic optical element (HOE) lens array according to an example embodiment.

Referring to <FIG>, an optical layer may include an HOE lens array. An HOE may have a narrow wavelength bandwidth and be used as an optical device only in a region of a predetermined wavelength. The HOE lens array may be manufactured using a general optical lens array <NUM> and a photopolymer <NUM>. The HOE lens array may be recorded, for example, on the photopolymer, in view of a position of a projector and a position of a predetermined viewing space. Recording the HOE lens array may be determining optical parameters of a plurality of optical elements included in the HOE lens array acting as an optical layer. For example, refractive indices of the optical elements included in the optical layer <NUM> or <NUM> may be determined in view of the position of the projector and the position of the predetermined viewing space.

The HOE lens array may be recorded using a reference beam incident from the position of the projector toward the general optical lens array <NUM> and the photopolymer <NUM> at a predetermined divergence angle α and a signal beam horizontally proceeding toward the predetermined viewing space in a state in which the general optical lens array <NUM> and the photopolymer <NUM> overlap. Although <FIG> illustrates the general optical lens array <NUM> being provided in a vertical direction, the general optical lens array <NUM> may also be manufactured in a horizontal direction or in both, vertical and horizontal, directions.

<FIG> illustrates a method of implementing an HOE lens array according to an example embodiment.

Referring to <FIG>, an HOE lens array <NUM> may be manufactured to refract or reflect only a light of a predetermined wavelength and to transmit a light of a wavelength other than the predetermined wavelength, and thereby act as a disparity separating device, for example, a parallax barrier or a lenticular lens. For example, the HOE lens array <NUM> manufactured using the method described with reference to <FIG> may respond only to RGB laser beams and transmit lights of the other wavelengths.

When a projector <NUM> is disposed at a position the same as that for recording and a light is scanned to the HOE lens array <NUM> at a predetermined divergence angle α, a user may observe a 3D image at a position of a predetermined viewing space <NUM>.

<FIG> illustrates a 3D display apparatus including a compensating lens according to an example embodiment.

Referring to <FIG>, a HUD system using the 3D display apparatus <NUM> is illustrated. The 3D display apparatus <NUM> may further include a compensating lens <NUM>.

The compensating lens <NUM> may be an image distortion correcting device. According to an example embodiment, by additionally providing the compensating lens <NUM> between the projector <NUM> and an optical layer <NUM> to correct an image distortion, a burden of the optical layer <NUM> may be reduced.

In another example embodiment, when manufacturing an HOE lens array, a plurality of HOE layers may be provided such that one layer may act as a lens array, and the other layer may perform a function to correct an image distortion.

<FIG> illustrates a 3D display apparatus including an immersion layer according to an embodiment.

An optical layer <NUM> refracts or reflects only a light of a predetermined wavelength and transmit a light of a wavelength other than the predetermined wavelength. The optical layer <NUM> may respond only to a laser beam scanned by a projector without affecting a transmittance of an external light using a wavelength selectivity, thereby removing a visibility by the external light.

Referring to <FIG>, to remove the visibility by the external light, an immersion layer <NUM> is applied to the optical layer <NUM>. According to an embodiment, the immersion layer <NUM> has an optical coating which selectively increases a reflectance with respect to a wavelength of a light scanned by the projector and increases a transmittance with respect to the other wavelengths. The immersion layer <NUM> and the optical layer <NUM> have the same refractive index according to the claimed invention.

For example, a refractive index n1 of the optical layer <NUM> may be identical to a refractive index n2 of the immersion layer <NUM>. Using the immersion layer <NUM> having a refractive index identical to that of the optical layer <NUM>, a distortion occurring at a target observed through the optical layer <NUM> is prevented.

<FIG> illustrates a circular display apparatus using a 3D display apparatus according to an example embodiment. The description provided with reference to <FIG> may also apply to <FIG>, and thus duplicate description will be omitted for conciseness.

Referring to <FIG>, a cylindrical display apparatus <NUM> using a 3D display apparatus may include a projector <NUM> and an optical layer <NUM>. The optical layer <NUM> may have a shape of a side of a cylinder. Hereinafter, for ease of description, a cylindrical display apparatus will be described. However, examples of the 3D display apparatus are not limited to the cylindrical display apparatus, and applied in various shapes.

The projector <NUM> may scan a light to the optical layer <NUM> through a <NUM>-degree rotation. The cylindrical display apparatus <NUM> may represent 3D spatial points using a plurality of optical elements <NUM> and <NUM> for a user to view at eyebox <NUM>.

<FIG> illustrate a method of implementing a 3D image using integral imaging according to an example embodiment.

Referring to <FIG>, a general integral imaging-based stereoscopic image display apparatus may include an image pickup <NUM> as illustrated in <FIG> and a display <NUM> as illustrated in <FIG>. According to an example embodiment, the image pickup <NUM> may convert 3D information of a 3D object <NUM> into a whole elemental image using a capturing device <NUM>, such as a camera and a first lens array <NUM>, and the image pickup <NUM> may store the elemental image in the capturing device <NUM>.

According to an example embodiment, the display <NUM> may include a display panel <NUM> and a second lens array <NUM>, and present the whole elemental image displayed on the display panel <NUM> in a form of a stereoscopic image <NUM> in a predetermined viewing space <NUM>.

According to general integral imaging, multiple viewing zones with different viewpoints may be formed. The integral imaging-based 3D image display apparatus may use a micro lens array as an optical array. When the micro lens array is used, beams output from the optical array may be controlled to be separated into left and right images in the viewing space.

For the 3D display apparatus to generate a 3D image according to integral imaging, an HOE lens array may be recorded in view of a position of a projector and a position of the predetermined viewing space such that the HOE lens array may act as the micro lens array.

According to an example embodiment, the description and features of one or more example embodiments in <FIG> may also apply to <FIG>, and thus duplicate description will be omitted for conciseness. For example, when implementing a 3D image according to integral imaging, scanned pixels as illustrated in <FIG> may output images corresponding to direction angles assigned to the corresponding pixels. A direction angle is an angle at which a beam is projected from a scanned pixel. By projecting the output images to the corresponding scanned pixels at predetermined direction angles, a 3D image may be implemented.

<FIG> illustrates a 3D display method according to an example embodiment.

Operations <NUM> and <NUM> may be performed by the 3D display apparatus <NUM> of <FIG>. The 3D display apparatus <NUM> may be implemented using one or more hardware modules, one or more software modules, or various combinations thereof.

In operation <NUM>, the 3D display apparatus <NUM> may obtain information related to a timing at which a light is scanned to an optical layer to provide a 3D image in a predetermined viewing space. For example, in operation <NUM>, the 3D display apparatus may obtain information about a first timing at which a red (R) scanned pixel may be formed, a second timing at which a green (G) scanned pixel may be formed, and a third timing at which the blue (B) scanned pixel may be formed.

In operation <NUM>, the 3D display apparatus <NUM> may control image information generated on the optical layer based on the information related to the timing at which the light is scanned. According to an example embodiment, during the first timing the 3D display apparatus may output only a red (R) laser beam to the position of the R subpixel of the RGB panel <NUM>, but refrain from outputting the green (G) and blue (B) laser beams. For instance, the 3D display apparatus may block the green (G) laser beam <NUM> and the blue (B) laser beam <NUM> at the first timing. A green (G) scanned pixel may be formed at a second timing and a blue (B) scanned pixel may be formed at a third timing based on the same principle described about with regard to the red (R) scanned pixel and based on the positions of the G subpixel and the B subpixel.

<FIG>, the illustrates a structure of the 3D display apparatus <NUM> according to an example embodiment. The 3D display apparatus <NUM> may include a processor <NUM>, a memory <NUM> and a communication interface <NUM>, which are all connected to and communicate with each other via a us <NUM>. According to an example embodiment, the "rendering" operation may be performed by the processor <NUM>. The processor <NUM> may control the image information based on a timing at which the light is scanned to the optical layer to provide the 3D image in the predetermined viewing space. The predetermined viewing space may refer to a space in which the user may continuously observe the 3D image at positions of the eyes of the user or positions in vicinity of the eyes, even when the user moves from side to side.

According to an embodiment, the processor <NUM> may communicate with the memory <NUM> to store data, retrieve data or retrieve instruction related to performing the control of the image information. According to example embodiment, the communication interface <NUM> may be configured to receive external input information and provide the received information to the memory <NUM> or the processor <NUM>. According to example embodiment, the communication interface <NUM> may be configured to output information processed by the processor <NUM> or retrieved from the memory.

According to an embodiment, the memory <NUM> may be configured to store one or more instructions; and the processor <NUM> may be configured to execute the one or more instructions to: obtain a first timing information associated with a first wavelength of a light, obtain a second timing information associated with a second wavelength of the light, control a projector to scan the light with the first wavelength onto an optical layer during a first timing period based on the first timing information and scan the light with the second wavelength onto the optical layer during a second timing period based on the second timing information and generate the 3D image in a viewing space based on the light scanned by the projector.

The example embodiments described herein may be implemented using a hardware component, a software component and/or a combination thereof. A processing device may be implemented using one or more general-purpose or special purpose computers, such as, for example, a processor, a controller and an arithmetic logic unit (ALU), a DSP, a microcomputer, an FPGA, a programmable logic unit (PLU), a microprocessor or any other device capable of responding to and executing instructions in a defined manner. The processing device may run an operating system (OS) and one or more software applications that run on the OS. The processing device also may access, store, manipulate, process, and create data in response to execution of the software. For purpose of simplicity, the description of a processing device is used as singular; however, one skilled in the art will appreciated that a processing device may include multiple processing elements and multiple types of processing elements. For example, a processing device may include multiple processors or a processor and a controller. In addition, different processing configurations are possible, such a parallel processors.

The software may include a computer program, a piece of code, an instruction, or some combination thereof, to independently or collectively instruct or configure the processing device to operate as desired.

Claim 1:
A three-dimensional, 3D, display apparatus comprising:
an optical layer (<NUM>, <NUM>, <NUM>) forming a lens array;
an immersion layer (<NUM>) applied to the optical layer (<NUM>), the immersion layer (<NUM>) and the optical layer (<NUM>) having a same refractive index;
an optical coating being an optical coating of the immersion layer (<NUM>) or an optical coating layer coated on the lens array, wherein the optical coating has a transmittance which changes based on a wavelength of the visible light;
a projector (<NUM>, <NUM>) configured to scan a light onto the optical layer (<NUM>, <NUM>, <NUM>); and
a processor (<NUM>) configured to control a timing at which the projector (<NUM>, <NUM>) scans the light onto the optical layer (<NUM>, <NUM>, <NUM>) and generate a 3D image (<NUM>) in a viewing space (<NUM>) based on the timing at which the light is scanned onto the optical layer (<NUM>, <NUM>, <NUM>), the 3D image (<NUM>) being a multiview image providing different images corresponding to two different viewpoints to a left eye and a right eye of a user, or an integral image forming multiple viewing zones by integrating elemental images including 3D information of a target object.