Device and method for displaying images and computer program thereof

Abstract

An image display device includes: a first waveguide, a second waveguide located on one side of the first waveguide, a first diffraction grating located on the other side of the first waveguide, a second diffraction grating located between the first waveguide and the second waveguide, and a display engine, the display engine being configured to control a shape of the second diffraction grating according to an amount of light diffracted from the first diffraction grating, wherein at least a portion of light incident on the first waveguide is diffracted from the first diffraction grating, and at least a portion of light incident on the second waveguide is diffracted from the second diffraction grating.

Description

Technical Field

[0001] The present disclosure relates to an apparatus for displaying an image, a method for displaying an image, and a computer program product including a recording medium storing a program for executing the method for displaying an image. Background Art

[0002] Augmented Reality (AR) technology is a technology used to synthesize virtual objects or information with the real environment so that the virtual objects or information look like real objects existing in the real environment. Recent computing and display technologies have made the development of AR experience systems possible. In an AR experience, digitally generated images or parts of images are provided to users in a way that makes them look real or that allows users to recognize them as real.

[0003] As interest in AR technology grows, various technologies for embodying AR are being actively developed. In particular, research on near-eye display technology for displaying images projected directly onto the user's retina is underway. Summary of the invention

[0004]

Technical issues

[0005] The disclosed embodiments relate to a method and apparatus for displaying an image to solve the problem of poor color uniformity due to uneven amounts of light diffracted in a waveguide.

[0006]

Technical solution

[0007] An image display device includes: a first waveguide, a second waveguide located on one side of the first waveguide, a first diffraction grating located on the other side of the first waveguide, a second diffraction grating located between the first waveguide and the second waveguide, and a display engine, the display engine being configured to control a shape of the second diffraction grating according to an amount of light diffracted from the first diffraction grating, wherein at least a portion of light incident on the first waveguide is diffracted from the first diffraction grating, and at least a portion of light incident on the second waveguide is diffracted from the second diffraction grating. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0009] Figure 1 is a view for describing characteristics of light diffracted by a diffraction grating located on a waveguide according to an embodiment;

[0010] Figure 2 is a view for describing a method of controlling the amount of light diffracted by a diffraction grating located on a waveguide, which is performed by the image display device according to the embodiment;

[0011] Figure 3 is a view for describing the structure of an image display device according to an embodiment;

[0012] Figure 4 is a flowchart for describing an image display method according to an embodiment;

[0013] Figure 5 is a view for describing the structure of an image display device according to an embodiment;

[0014] Figure 6 is a view for describing the structure of an image display device according to an embodiment;

[0015] Figure 7 is a view for describing an example of the shape of a second diffraction grating included in the image display device according to the embodiment;

[0016] Figure 8 is a view for describing an example of the shape of a second diffraction grating included in the image display device according to the embodiment;

[0017] Fig. 9 is a view for describing a method of controlling light output by considering characteristics of an object included in a virtual image, performed by an image display device according to an embodiment;

[0018] Fig.10 is a view for describing an example of controlling light output by considering the kind of executed application, which is performed by the image display device according to the embodiment; and

[0019] Fig.11 is a view for describing an example of controlling light output by considering the kind of executed application, which is performed by the image display device according to the embodiment. DETAILED DESCRIPTION

[0020] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0021] According to one aspect of the present disclosure, an image display device includes: a first waveguide; a second waveguide located on one side of the first waveguide; a first diffraction grating located on the other side of the first waveguide; a second diffraction grating located between the first waveguide and the second waveguide; and a display engine configured to control a shape of the second diffraction grating according to an amount of light diffracted from the first diffraction grating, wherein at least a portion of light incident on the first waveguide is diffracted from the first diffraction grating, and at least a portion of light incident on the second waveguide is diffracted from the second diffraction grating.

[0022] The processor may also be configured to identify an amount of light diffracted from the first diffraction grating; obtain information about a shape of the second diffraction grating for compensating the amount of light diffracted from the first diffraction grating so that a total amount of light diffracted from the first waveguide and the second waveguide is uniform; and apply an electrical signal to the second diffraction grating based on the obtained information about the shape of the second diffraction grating.

[0023] Information on at least one of the pattern or the length of the second diffraction grating can be obtained based on the amount of light diffracted from the first diffraction grating.

[0024] The second diffraction grating may include at least one of a liquid crystal (LC) panel, an LC lens, and an active diffraction device.

[0025] The image display device may further include an optical path controller, wherein an amount of light incident on the first waveguide and the second waveguide is controlled by the optical path controller, and the optical path controller includes at least one of a half mirror, a total mirror, or a liquid crystal lens.

[0026] The processor may also be configured to obtain information about the color of light from a real-world image incident on the image display device; and control the shape of the second diffraction grating according to the information about the color and amount of light diffracted from the first diffraction grating.

[0027] The image display device may further include a third waveguide on which a third diffraction grating is located, and a fourth waveguide on which a fourth diffraction grating is located, wherein light formed from at least one image signal among a red (R) image signal, a green (G) image signal, and a blue (B) image signal constituting a virtual image is selectively diffracted from the first diffraction grating and the second diffraction grating, light formed from image signals other than the at least one image signal among the R image signal, the G image signal, and the B image signal is diffracted from the third diffraction grating, and information about the shape of the fourth diffraction grating is obtained based on characteristics of the light diffracted from the third diffraction grating.

[0028] The processor may be further configured to identify an application being executed in the image display device, and control a shape of the second diffraction grating according to the determined application and an amount of light diffracted from the first diffraction grating.

[0029] According to one aspect of the present disclosure, an image display method includes: obtaining information about the amount of light diffracted from a first diffraction grating; based on the information about the amount of light diffracted from the first diffraction grating, obtaining information about the shape of the second diffraction grating for controlling the amount of light diffracted from the second diffraction grating, wherein the first diffraction grating is located on the other side of a first waveguide and the second diffraction grating is located between the first waveguide and the second waveguide; based on the information about the shape of the second diffraction grating, applying an electrical signal to the second diffraction grating; and outputting light constituting a virtual image to the first waveguide and the second waveguide, respectively.

[0030] Mode for carrying out the invention

[0031] The terms used in the specification will be briefly described, and the present disclosure will be described in detail.

[0032] The terms used in this disclosure are selected in consideration of the disclosed functions. The meanings of these terms may vary according to the intentions of those skilled in the art, judicial precedents, the emergence of new technologies, and the like. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meanings as those commonly understood by those skilled in the art to which the exemplary embodiments belong. It should also be understood that terms, such as those defined in general dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0033] It should be understood that although the terms first, second, etc. can be used in this article to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another component. For example, without departing from the scope of the present disclosure, a first component can be referred to as a second component, and similarly, a second component can be referred to as a first component. As used herein, the term "and / or" includes any and all combinations of one or more of the related listed items.

[0034] In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, the presence of the components is specified, but the presence or addition of one or more other components is not excluded. The term "part" refers to a software or hardware component, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and the "parts" each perform a specified function. However, the "parts" are not limited to software or hardware. The "parts" can be configured in an addressable storage medium, or can be configured to run on at least one processor. Therefore, as an example, the "parts" include: components such as software components, object-oriented software components, class components, and task components; processors, functions, properties, procedures, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided by the components and "parts" can be combined into fewer components, and / or the "parts" can be divided into additional components and "parts".

[0035] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present disclosure. However, the present disclosure is not limited to these embodiments, but can be implemented in many different forms. In addition, in the accompanying drawings, in order to simplify the description, parts not related to the description are omitted, and the same reference numerals will refer to the same components throughout the specification.

[0036] Throughout the disclosure, the expression "at least one of a, b, or c" means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0037] Figure 1 1 is a view for describing characteristics of light diffracted by a plurality of diffraction gratings 120a and 120b located on a plurality of waveguides 110a and 110b.

[0038] refer to Figure 1 , light may be irradiated to the waveguides 110a and 110b on which the diffraction gratings 120a and 120b are located, so that the light may be perceived by the left and right eyes of the user, respectively. The light may be formed from a red (R) image signal, a green (G) image signal, and a blue (B) image signal constituting a virtual image.

[0039] At the same time, at least a portion of the light irradiated to the waveguides 110a and 110b may be diffracted by the diffraction gratings 120a and 120b, and the rest of the light may be projected away from the user's eyes. The quantity (i.e., amount) of the diffracted light may vary within each of the diffraction gratings 120a and 120b. For example, an area (i.e., region) of the diffraction grating farther from the position of the irradiated light may diffract a smaller amount of light than another area of ​​the diffraction grating closer to the position of the irradiated light.

[0040] refer to Figure 1 , the phenomenon that the amount of diffracted light decreases will be described by using, for example, a case in which light formed from an R image signal, a G image signal, and a B image signal constituting a virtual image including an apple is incident on waveguides 110a and 110b, respectively. In the current embodiment, it is assumed that diffraction gratings 120a and 120b selectively diffract light formed from the R image signal and the G image signal, respectively. The amount of light diffracted by diffraction gratings 120a and 120b may decrease as the distance from the incident point of the light on the corresponding waveguide increases. Specifically, as Figure 1 As shown, in the case of the waveguides 110 a and 110 b according to the present embodiment, it can be confirmed that the amount of light formed from the R signal largely depends on the area where the light is diffracted.

[0041] Since the amount of light diffracted by the diffraction gratings 120a and 120b largely depends on the area where the light of the diffraction gratings 120a and 120b is diffracted, the red color of the apple images 10a and 10b recognized by the left and right eyes of the user may be uneven. Therefore, there is a need for an image display device for controlling the diffraction grating to emit light that forms a virtual image of uniform color on the retina of the user. Hereinafter, reference will be made to Figures 2 to 11 A method of controlling a diffraction grating to emit light forming a virtual image of uniform color according to an embodiment is described.

[0042] Figure 2 2 is a view for describing a method of controlling the amount of light diffracted by a plurality of diffraction gratings 220a, 220b, 240a, and 240b located on a plurality of waveguides 210a, 210b, 230a, and 230b, which is performed by the image display device according to the embodiment.

[0043] refer to Figure 2, light can be irradiated to the waveguides 210a, 210b, 230a and 230b on which the diffraction gratings 220a, 220b, 240a and 240b are located, so that the light can be recognized by the left and right eyes of the user. In this article, the light can be formed from the R image signal, the G image signal and the B image signal constituting the virtual image. In the current embodiment, for the convenience of description, the waveguides 210a, 210b, 230a and 230b having a stacked structure will be referred to as first waveguides 210a and 210b and second waveguides 230a and 230b. In addition, the diffraction gratings 220a and 220b located on the first waveguides 210a and 210b can be referred to as first diffraction gratings, and the diffraction gratings 240a and 240b located on the second waveguides 230a and 230b can be referred to as second diffraction gratings.

[0044] In the current embodiment, for example, the first diffraction gratings 220a and 220b may selectively diffract light generated by the R image signal, and the second diffraction gratings 240a and 240b may selectively diffract light generated by the G image signal. The amount of light diffracted by the first diffraction gratings 220a and 220b may decrease as the distance from the incident point of the light on the corresponding first waveguides 210a and 210b increases.

[0045] Meanwhile, the image display device according to the embodiment may determine the shape (i.e., diffraction pattern) of the second diffraction gratings 240a and 240b to compensate for the reduced amount of light at the region where the amount of light diffracted by the first diffraction gratings 220a and 220b is reduced. For example, when the amount of light diffracted at a region spaced a predetermined distance from a first point close to the point where light is incident on the first diffraction gratings 220a and 220b is smaller than the amount of light diffracted at the first point by an amount of light x, the image display device may determine the shape of the second diffraction gratings 240a and 240b so that the amount of light x is diffracted by the second diffraction gratings 240a and 240b at a position corresponding to the region. In other words, the shape of the second diffraction gratings 240a and 240b may be controlled to compensate for the positional variation of the amount of light diffracted by the first diffraction gratings 220a and 220b. The image display device may apply an electrical signal corresponding to the determined shape of the second diffraction gratings 240a and 240b to the second diffraction gratings 240a and 240b to change the shape of the second diffraction gratings 240a and 240b.

[0046] When the amount of light diffracted by the first diffraction gratings 220a and 220b is uneven, the image display device according to the embodiment can compensate for the uneven amount of light by controlling the shapes of the second diffraction gratings 240a and 240b so that the left and right eyes of the user can uniformly recognize the color of the virtual image. Figure 1Unlike the described embodiment, the user can recognize the entire apple images 20a and 20b as a uniform red color through his / her left eye and right eye.

[0047] Figure 3 is a view for describing the structure of an image display device 300 according to an embodiment.

[0048] refer to Figure 3 , the image display device 300 may include a first waveguide 310, a first diffraction grating 320, a second waveguide 330, a second diffraction grating 340, and a display engine 350. However, the configuration of the image display device 300 is an example. That is, in addition to the above components, the image display device 300 may further include other components, or omit some of the above components.

[0049] According to an embodiment of the present disclosure, the first waveguide 310 and the second waveguide 330 may have a stacked structure. Figure 3 As shown, the second waveguide 330 may be stacked on the first waveguide 310. In addition, the first waveguide 310 and the second waveguide 330 may receive light formed of an R image signal, a G image signal, and a B image signal constituting a virtual image from the display engine 350.

[0050] The first diffraction grating 320 may be located on the first waveguide 310 to diffract at least a portion of the light received by the first waveguide 310. Also, the second diffraction grating 340 may be located on the second waveguide 330 to diffract at least a portion of the light received by the second waveguide 330.

[0051] Meanwhile, the second diffraction grating 340 may be an active device whose shape may be changed according to an electrical signal received from the display engine 350. For example, the second diffraction grating 340 may include at least one of a liquid crystal (LC) panel, an LC lens, or an active diffraction device.

[0052] The display engine 350 according to the embodiment may control the shape of the second diffraction grating 340 according to the amount of light diffracted by the first diffraction grating 320. For example, the display engine 350 may determine at least one of the pattern or the length of the second diffraction grating 340 according to the amount of light diffracted by the first diffraction grating 320.

[0053] The process of controlling the shape of the second diffraction grating 340 performed by the display engine 350 will be described in detail as follows. Before determining the shape of the second diffraction grating 340, the display engine 350 may determine the amount of light diffracted by the first diffraction grating 320 according to the area of ​​the first diffraction grating 320. In other words, the display engine 350 may detect the amount of light diffracted by the first diffraction grating 320 at different positions along the first diffraction grating 320. In addition, the display engine 350 may determine the shape of the second diffraction grating 340 for compensating the amount of light diffracted by the first diffraction grating 320 so that the amount of light diffracted in the image display device 300 and reaching the user's eyes is uniform. The display engine 350 may apply an electrical signal corresponding to the determined shape of the second diffraction grating 340 to the second diffraction grating 340.

[0054] Meanwhile, according to another embodiment, the display engine 350 may determine the color of the real-world image perceived by the image display device 300, and control the shape of the second diffraction grating 340 according to the determined color and the amount of light diffracted by the first diffraction grating 320. According to an example, the display engine 350 may determine the wavelength of the light to be diffracted by the second diffraction grating 340 to correspond to the color of the real-world image. For example, when the color of the real-world image is determined to be reddish, the display engine 350 may determine that the wavelength λ2 of the diffracted virtual image may be more effective in identifying the reddish component in the virtual image than typically diffracting the wavelength λ1, so that the user can more clearly identify the R image signal of the virtual image. Therefore, the display engine 350 may determine the shape of the second diffraction grating 340 to selectively diffract the light corresponding to the wavelength λ2 among the received light, instead of the wavelength λ1, so that when the real-world image is also reddish, the user can more clearly identify the red virtual image. Furthermore, the display engine 350 may determine the amount of the wavelength λ2 to be diffracted by each region of the second diffraction grating 340 according to the amount of light diffracted by the first diffraction grating 320 .

[0055] That is, the display engine 350 may control the shape of the second diffraction grating 340 according to the determined amount of light and the determined wavelength of light.

[0056] According to another embodiment, the display engine 350 may determine the type of application currently being executed on the image display device 300 so that the virtual image is displayed. The display engine 350 may control the shape of the second diffraction grating 340 according to the determined type of application and the amount of light diffracted by the first diffraction grating 320.

[0057] For example, a video playback application may require a relatively higher brightness than a navigation application. Therefore, when the video playback application is executed, the display engine 350 can control the shape of the second diffraction grating 340 to diffract a relatively large amount of light. In addition, a navigation application may require a relatively low brightness. Therefore, when the navigation application is executed, the display engine 350 can control the shape of the second diffraction grating 340 to diffract a relatively small amount of light.

[0058] Figure 4 is a flowchart for describing an image display method according to an embodiment.

[0059] In operation S410, the image display device may determine the amount of diffracted light according to the area of ​​the first diffraction grating on the first waveguide among the plurality of waveguides in the stacked structure. For example, because the amount of light diffracted by the first diffraction grating decreases at an area farther from the point where light is incident, the image display device may determine the amount of diffracted light according to the area of ​​the first diffraction grating from the point where light is incident. In other words, the image display device may determine the relationship between the amount of light diffracted by the first diffraction grating and the distance from the incident point on the first waveguide.

[0060] In operation S420, the image display device may determine the shape of the second diffraction grating for controlling the amount of diffracted light according to the area of ​​the second diffraction grating located on the second waveguide stacked on one surface of the first waveguide based on the determined amount of light. In other words, the image display device may determine the shape of the second diffraction grating that compensates for the change in the amount of light diffracted by the first diffraction grating.

[0061] According to an embodiment, the image display device may determine the shape of the second diffraction grating for diffracting light at an area of ​​the second diffraction grating corresponding to an area where the amount of light of the first diffraction grating is reduced to compensate for the amount of light reduced at the area of ​​the first diffraction grating. At this time, the image display device may determine the shape of the second diffraction grating so that the sum of the amounts of light diffracted by the first diffraction grating and the second diffraction grating, respectively, is uniform over the entire area of ​​the first and second diffraction gratings. For example, when the amount of light diffracted at the first area of ​​the first diffraction grating is a and the amount of light diffracted at the second area of ​​the first diffraction grating is a / 2, the image display device may determine the shape of the second diffraction grating so that the amount of light diffracted at the area of ​​the second diffraction grating corresponding to the second area of ​​the first diffraction grating becomes a / 2. Therefore, the total amount of light diffracted by the second area becomes a, which is the same as the total amount of light diffracted by the first area.

[0062] In operation S430, the image display device may apply an electrical signal corresponding to the determined shape of the second diffraction grating to the second diffraction grating. The second diffraction grating may be one of various active devices whose shape changes when receiving an electrical signal.

[0063] In operation S440, the image display device may output light formed from the R image signal, the G image signal, and the B image signal constituting the virtual image to the first waveguide and the second waveguide. The image display device may change the pattern of the second diffraction grating so that an electrical signal is applied to emit a uniform amount of light, and then may emit light.

[0064] Figure 5 is a view for describing a structure of an image display device 500 according to another embodiment.

[0065] refer to Figure 5 , the image display device 500 may include a first waveguide 510, a first diffraction grating 520, a second waveguide 530, a second diffraction grating 540, a display engine 550, and an optical path controller 560. However, the configuration of the image display device 500 is an example. That is, in addition to the above components, the image display device 500 may further include other components, or omit some of the above components.

[0066] In the current embodiment of the present disclosure, the first waveguide 510, the first diffraction grating 520, the second waveguide 530, the second diffraction grating 540, and the display engine 550 may correspond to the above reference numerals, respectively. Figure 3 The first waveguide 310, the first diffraction grating 320, the second waveguide 330, the second diffraction grating 340 and the display engine 350 described above are shown in FIG. Figure 3 The given description will be omitted.

[0067] The display engine 550 may determine a pattern of the second diffraction grating 540 for compensating for the area where the amount of light of the first diffraction grating 520 is reduced so that the image display device 500 emits a uniform amount of light. In addition, the display engine 550 may apply an electrical signal corresponding to the determined pattern of the second diffraction grating 540 to the second diffraction grating 540.

[0068] Meanwhile, the display engine 550 may output light formed from the R image signal, the G image signal, and the B image signal constituting the virtual image to the light path controller 560 .

[0069] The optical path controller 560 may control the optical path received from the display engine 550 to increase the amount of light incident on the first waveguide 510 and the second waveguide 530, respectively, while satisfying the total reflection condition. The optical path controller 560 may include, for example, at least one of a half mirror, a total mirror, or a liquid crystal lens to guide the light emitted from the display engine 550 to the first waveguide 510 and the second waveguide 530.

[0070] Light incident from the optical path controller 560 to the first waveguide 510 and the second waveguide 530 may be diffracted by the first diffraction grating 520 and the second diffraction grating 540 to be recognized by the user's retina.

[0071] Figure 6 is a view for describing the structure of an image display device 600 according to another embodiment.

[0072] refer to Figure 6 , the image display device 600 may include a first waveguide 610, a first diffraction grating 620, a second waveguide 630, a second diffraction grating 640, a third waveguide 650, a third diffraction grating 660, a fourth waveguide 670, a fourth diffraction grating 680, and a display engine 690. However, the configuration of the image display device 600 is an example. That is, in addition to the above components, the image display device 600 may further include other components, or omit some of the above components.

[0073] According to an embodiment, the first waveguide 610, the second waveguide 630, the third waveguide 650, and the fourth waveguide 670 may have a stacked structure. Each of the first waveguide 610, the second waveguide 630, the third waveguide 650, and the fourth waveguide 670 may receive light formed of an R image signal, a G image signal, and a B image signal constituting a virtual image from the display engine 690.

[0074] The first diffraction grating 620 may be located on the first waveguide 610 to diffract at least a portion of light formed of the R image signal and the G image signal among the light received by the first waveguide 610. The first diffraction grating 620 may thus transmit the light formed of the B image signal. In addition, the second diffraction grating 640 may be located on the second waveguide 630 to diffract at least a portion of light formed of the R image signal and the G image signal among the light received by the second waveguide 630. The second diffraction grating 640 may thus transmit the light formed of the B image signal. In addition, the second diffraction grating 640 may be an active device whose shape changes according to an electrical signal applied from the display engine 690.

[0075] Display engine 690 may determine the shape of second diffraction grating 640 for compensating the amount of light diffracted by first diffraction grating 620. Therefore, the amount of light of the R image signal and the G image signal diffracted in image display device 600 may be controlled to be uniform. Display engine 690 may apply an electrical signal corresponding to the determined shape of second diffraction grating 640 to second diffraction grating 640.

[0076] Meanwhile, third diffraction grating 660 may be located on third waveguide 650 to diffract at least a portion of light formed of the B image signal among the light received by third waveguide 650. Third diffraction grating 660 may thus transmit light formed of the R image signal and the G image signal. Furthermore, fourth diffraction grating 680 may be located on fourth waveguide 670 to diffract at least a portion of light formed of the B image signal among the light received by fourth waveguide 670. Fourth diffraction grating 680 may thus transmit light formed of the R image signal and the G image signal. Furthermore, fourth diffraction grating 680 may be an active device whose shape changes according to an electrical signal applied from display engine 690.

[0077] The display engine 690 may determine the shape of the fourth diffraction grating 680 for compensating the amount of light diffracted by the third diffraction grating 660 so that the amount of light of the B image signal diffracted in the image display device 600 is uniform. The display engine 690 may apply an electrical signal corresponding to the determined shape of the fourth diffraction grating 680 to the fourth diffraction grating 680. In other words, the third and fourth diffraction gratings 660 and 680 may be configured to perform the same function on the B signal as the functions performed by the first and second diffraction gratings 620 and 640 on the R and G signals.

[0078] Meanwhile, the waveguides 610, 630, 650, and 670 of the image display device 600 are not limited to Figure 6 According to another example, when each waveguide is configured to selectively diffract only one of the lights formed by the R image signal, the G image signal, and the B image signal, six waveguides of the stacked structure may be included in the image display device. In this case, six diffraction gratings may be respectively located on the six waveguides, and three of the diffraction gratings may be configured as active devices for compensating for the amount of light diffracted by the remaining three diffraction gratings.

[0079] Figure 7 7 is a view for describing an example of the shape of the second diffraction grating 740 included in the image display device 700 according to the embodiment.

[0080] refer to Figure 7 , the image display device 700 may include a first waveguide 710, a first diffraction grating 720, a second waveguide 730, a second diffraction grating 740, and a display engine 750. The first waveguide 710, the first diffraction grating 720, the second waveguide 730, the second diffraction grating 740, and the display engine 750 may correspond to the above reference numerals. Figure 3 The first waveguide 310, the first diffraction grating 320, the second waveguide 330, the second diffraction grating 340 and the display engine 350 are described. Figure 7As shown, the first diffraction grating 720 does not extend to the end of the first waveguide 710 opposite to the incident point of the light emitted by the display engine 750. Therefore, in the area farthest from the incident point, no light is diffracted by the first diffraction grating 720. On the other hand, there is a gap in the middle area of ​​the second diffraction grating 740, so that no light is diffracted by the second diffraction grating 740 in this area.

[0081] The display engine 750 may control the shape of the second diffraction grating 740 according to the amount of light diffracted by the first diffraction grating 720. For example, the amount of diffracted light may be reduced at regions close to both ends of the first diffraction grating 720 (i.e., at the ends of the first diffraction grating 720). In this case, the display engine 750 may determine the shape of the second diffraction grating 740 located on the second waveguide 730 to diffract light at regions of the second diffraction grating 740 corresponding to both ends of the first diffraction grating 720, such as Figure 7 shown.

[0082] Figure 8 is a view for describing an example of the shape of the second diffraction grating 840 included in the image display device 800 according to the embodiment.

[0083] refer to Figure 8 , the image display device 800 may include a first waveguide 810, a first diffraction grating 820, a second waveguide 830, a second diffraction grating 840, and a display engine 850. The first waveguide 810, the first diffraction grating 820, the second waveguide 830, the second diffraction grating 840, and the display engine 850 may correspond to the above reference numerals. Figure 3 The first waveguide 310, the first diffraction grating 320, the second waveguide 330, the second diffraction grating 340 and the display engine 350 are described. Figure 8 As shown, the second diffraction grating 840 does not extend to the end of the second waveguide 830 opposite to the incident point of the light emitted by the display engine 850. In addition, the second diffraction grating 840 does not extend to the end of the first diffraction grating 820 closest to the incident point. Therefore, no light is diffracted by the second diffraction grating 840 in these areas.

[0084] The display engine 850 may control the shape of the second diffraction grating 840 according to the amount of light diffracted by the first diffraction grating 820. For example, the amount of diffracted light may be reduced around the central region of the first diffraction grating 820 (i.e., in the middle portion of the first diffraction grating 820). In this case, the display engine 850 may determine the shape of the second diffraction grating 840 positioned on the second waveguide 830 to diffract light at a region of the second diffraction grating 840 corresponding to the central region of the first diffraction grating 820, such as Figure 8 shown.

[0085] Fig. 9 is a view for describing a method of controlling light output by considering characteristics of an object included in a virtual image, performed by the image display device 900 according to an embodiment.

[0086] refer to Fig. 9 , the image display device 900 may include a first waveguide 910, a first diffraction grating 920, a second waveguide 930, a second diffraction grating 940, and a display engine 950. The first waveguide 910, the first diffraction grating 920, the second waveguide 930, the second diffraction grating 940, and the display engine 950 may correspond to the above reference numerals. Figure 3 The first waveguide 310, the first diffraction grating 320, the second waveguide 330, the second diffraction grating 340 and the display engine 350 are described. Fig. 9 As shown, the first diffraction grating 920 does not extend to the end of the first waveguide 910 opposite to the incident point of the light emitted by the display engine 950. Therefore, in the area farthest from the incident point, no light is diffracted by the first diffraction grating 920. On the other hand, there is a gap in the middle area of ​​the second diffraction grating 940, so that no light is diffracted by the second diffraction grating 940 in this area.

[0087] The display engine 950 may output light that forms a virtual image including an object. The display engine 950 according to an embodiment of the present disclosure may change the shape of the second diffraction grating 940 to control the brightness of an area including the object or an area around the object. Here, the object may be a thing, a person, an animal, etc. In the current embodiment, a teddy bear will be described as an example of an object.

[0088] When outputting a virtual image including a teddy bear, the display engine 950 may control the shape of the second diffraction grating 940 to output a relatively high brightness at an area around the teddy bear. For example, the display engine 950 may determine the shape of the second diffraction grating 940 to diffract a relatively large amount of light at an area of ​​the second diffraction grating 940 corresponding to an outline area of ​​the teddy bear.

[0089] The display engine 950 may apply an electrical signal to the second diffraction grating 940 according to the determined shape of the second diffraction grating 940 .

[0090] Fig.10 is a view for describing an example of controlling light output by considering the kind of executed application, which is performed by the image display device 1000 according to the embodiment.

[0091] refer to Fig.10, the image display device 1000 may include a first waveguide 1010, a first diffraction grating 1020, a second waveguide 1030, a second diffraction grating 1040, and a display engine 1050. The first waveguide 1010, the first diffraction grating 1020, the second waveguide 1030, the second diffraction grating 1040, and the display engine 1050 may correspond to the above reference 1000, respectively. Figure 3 The first waveguide 310, the first diffraction grating 320, the second waveguide 330, the second diffraction grating 340 and the display engine 350 are described. Fig.10 As shown, the second diffraction grating 1040 does not extend to the end of the first diffraction grating 1020 closest to the incident point. Therefore, no light is diffracted by the second diffraction grating 1040 in this area.

[0092] Meanwhile, in the current embodiment of the present disclosure, it is assumed that a video playback application is executed on the image display device 1000 .

[0093] The display engine 1050 may determine the kind of the application being executed on the image display device 1000. For example, the display engine 1050 may determine that the application being executed on the image display device 1000 is a video playback application.

[0094] The video playback application may require the output of a high-brightness virtual image to increase the user's attention to the video being played. Therefore, the display engine 1050 may control the shape of the second diffraction grating 1040 so that a virtual image of a brightness suitable for the video playback application can be recognized by the user's retina. For example, the display engine 1050 may determine the amount of light that needs to be diffracted to output a virtual image of a brightness suitable for the video playback application, and determine the shape of the second diffraction grating 1040 based on the determined amount of light. In addition, the display engine 1050 may apply an electrical signal corresponding to the determined shape of the second diffraction grating 1040 to the second diffraction grating 1040, so that the second diffraction grating 1040 changes to the determined shape.

[0095] Meanwhile, the display engine 1050 may determine a portion of the diffracted light by considering the type of application, and control the light output by considering the amount of diffracted light according to the area of ​​the first diffraction grating 1020 so that a uniform amount of light is output to suit the type of application.

[0096] Fig.11 is a view for describing another example of controlling light output by considering the kind of executed application, which is performed by the image display device 1100 according to the embodiment.

[0097] refer to Fig.11, the image display device 1100 may include a first waveguide 1110, a first diffraction grating 1120, a second waveguide 1130, a second diffraction grating 1140, and a display engine 1150. The first waveguide 1110, the first diffraction grating 1120, the second waveguide 1130, the second diffraction grating 1140, and the display engine 1150 may correspond to the above reference 1100, ... Figure 3 The first waveguide 310, the first diffraction grating 320, the second waveguide 330, the second diffraction grating 340 and the display engine 350 are described. Fig.11 As shown, the second diffraction grating 1140 does not extend to the end of the first diffraction grating 1120 closest to the incident point. Therefore, no light is diffracted by the second diffraction grating 1140 in this area.

[0098] Meanwhile, in the current embodiment of the present disclosure, it is assumed that a navigation application is executed on the image display device 1100 .

[0099] The display engine 1150 may determine the kind of the application being executed on the image display device 1100. For example, the display engine 1150 may determine that the application being executed on the image display device 1100 is a navigation application.

[0100] The navigation application may require the output of a virtual image of relatively low brightness because the virtual image overlapping with the real-world image needs to be recognized. Therefore, the display engine 1150 may control the shape of the second diffraction grating 1140 so that the virtual image of the brightness suitable for the navigation application can be recognized by the user's retina. For example, the display engine 1150 may determine the amount of light that needs to be diffracted to output a virtual image of the brightness suitable for the navigation application, and determine the shape of the second diffraction grating 1140 according to the determined amount of light. In addition, the display engine 1150 may apply an electrical signal corresponding to the determined shape of the second diffraction grating 1140 to the second diffraction grating 1140, so that the second diffraction grating 1140 changes to the determined shape.

[0101] Meanwhile, the display engine 1150 may determine a portion of the diffracted light by considering the kind of application, and control the light output by considering the amount of light diffracted by the first diffraction grating 1120 so that a uniform amount of light is output to suit the kind of application.

[0102] The method according to the embodiment can be implemented in the form of a program command, which can be executed by various computer devices and stored in a computer-readable medium. The computer-readable medium can also include data files, data structures, etc., alone or in combination with the program command. The program commands recorded on the medium can be specially designed and constructed for the present disclosure, or they can be types known and available to technicians in the field of computer software. Examples of computer-readable media include: magnetic media, such as hard disks, floppy disks, and tapes; optical media, such as CD ROMs and DVDs; magneto-optical media, such as optical magnetic floppy disks; and hardware devices specially configured to store and execute program commands, such as read-only memory (ROM), random access memory (RAM), flash memory, etc. Examples of program commands include machine codes such as those generated by a compiler, and both high-level codes that can be executed by a computer using an interpreter.

[0103] In the embodiments shown in the drawings, reference numerals are indicated and specific terms are used to describe the embodiments, however, the present disclosure is not limited by these terms. The embodiments may include all components that can be generally understood by those of ordinary skill in the art.

[0104] Embodiments can be represented by function block configurations and various processing operations. These function blocks can be implemented by various numbers of hardware and / or software configurations that perform specific functions. For example, embodiments can adopt integrated circuit configurations, such as memory, processing, logic, lookup tables, etc., which can perform various functions by the control of one or more microprocessors or different control devices. In addition, embodiments can adopt the same or different types of cores and different types of CPUs. Similarly, components are executed by software programming or software elements, and embodiments can be implemented with programming or scripting languages ​​(such as C, C++, Java, assembler, etc.), including various algorithms implemented by a combination of data structures, processes, routines or other programming structures. Functional aspects can be implemented with algorithms executed by one or more processors. In addition, embodiments can adopt typical techniques for electronic environment settings, signal processing and / or data processing, etc. The terms "mechanism", "factor", "device" and "configuration" can be used in a broad sense and may not be limited to mechanical and physical configurations. These terms can include the meaning of a series of software routines that interact with processors, etc.

[0105] The specific execution described in the embodiment is an example, and does not limit the scope of the embodiment even in any method. For the simplicity of the specification, the description of other functional aspects of typical electronic configurations, control systems, software and systems may be omitted. In addition, the connection of the lines or connectors between the components shown in the drawings shows functional connections and / or physical or circuit connections. These connections can be replaced, or can be represented as additional various functional connections, physical connections or circuit connections in actual devices. When there is no detailed mention such as "necessary", "important", etc., the corresponding component may not be an absolutely necessary component.

[0106] In the current specification (especially in the claims), the term "described" and similar indicative terms can be used in both singular and plural forms. In addition, the term "range" can include a single value belonging to the "range" (unless the context clearly indicates otherwise). That is, writing a range in the detailed description can be the same as writing a single value constituting the range in the detailed description. Finally, the operations constituting the method can be performed in any appropriate order, unless the order of the operations is specified or the context clearly indicates otherwise. That is, these operations are not necessarily performed in the order in which they are written. So far, example embodiments have been described. However, it is obvious that various modifications can be made to them by those skilled in the art without changing the inherent characteristics of the present disclosure. Therefore, it should be understood that the above example embodiments are only for the purpose of illustration, not for the purpose of limitation. The scope of the present disclosure is defined by the claims rather than the detailed description, and all differences within the equivalent range should be interpreted as belonging to the scope of the present disclosure.

Claims

1. An image display device, comprising: First Waveguide; a second waveguide, located on one side of the first waveguide; a first diffraction grating, located on the other side of the first waveguide; a second diffraction grating disposed between the first waveguide and the second waveguide; and The processor is configured as: identifying an amount of light diffracted from the first diffraction grating, wherein at least a portion of the light incident on the first waveguide is diffracted from the first diffraction grating, obtaining information about the shape of the second diffraction grating for compensating the identified amount of light diffracted from the first diffraction grating so that total amounts of light diffracted from the first waveguide and the second waveguide are uniform; as well as Based on the obtained information about the shape of the second diffraction grating, an electric signal is applied to the second diffraction grating to change the shape of the second diffraction grating.

2. The image display device according to claim 1, wherein: Information on at least one of a pattern or a length of the second diffraction grating is obtained based on the amount of light diffracted from the first diffraction grating.

3. The image display device according to claim 1, wherein: The second diffraction grating includes at least one of a liquid crystal panel, a liquid crystal lens, or an active diffraction device.

4. The image display device according to claim 1, further comprising a light path controller, in, The amount of light incident on the first waveguide and the second waveguide is controlled by the optical path controller, and The optical path controller includes at least one of a half-reflecting mirror, a total-reflecting mirror or a liquid crystal lens.

5. The image display device according to claim 1, further comprising: a third waveguide, a third diffraction grating being located on the third waveguide, and a fourth waveguide, a fourth diffraction grating being located on the fourth waveguide, wherein light formed from at least one image signal among a red image signal, a green image signal, and a blue image signal constituting a virtual image is selectively diffracted from the first diffraction grating and the second diffraction grating, light formed from an image signal other than the at least one image signal among the red image signal, the green image signal, and the blue image signal is diffracted from the third diffraction grating, and Information on the shape of the fourth diffraction grating is obtained based on characteristics of light diffracted from the third diffraction grating.

6. The image display device according to claim 1, wherein: The processor is further configured to: identifying an application being executed in the image display device, and The shape of the second diffraction grating is controlled according to the identified application and the amount of light diffracted from the first diffraction grating.

7. An image display method, comprising: obtaining information about an amount of light diffracted from the first diffraction grating; obtaining information about a shape of a second diffraction grating for compensating an amount of light diffracted from the first diffraction grating so that a total amount of light diffracted from a first waveguide and a second waveguide is uniform, wherein the second waveguide is located on one side of the first waveguide, the first diffraction grating is located on the other side of the first waveguide, and the second diffraction grating is located between the first waveguide and the second waveguide; applying an electrical signal to the second diffraction grating to change the shape of the second diffraction grating based on information about the shape of the second diffraction grating; as well as Light constituting a virtual image is output to the first waveguide and the second waveguide, respectively.

8. The method according to claim 7, wherein: Information on at least one of a pattern or a length of the second diffraction grating is obtained based on the amount of light diffracted from the first diffraction grating.

9. The method according to claim 7, wherein: The second diffraction grating includes at least one of a liquid crystal panel, a liquid crystal lens, or an active diffraction device.

10. The method of claim 7, further comprising obtaining information about the color of the light from a real-world image to be displayed, in, Obtaining information about the shape of the second diffraction grating includes obtaining information about the shape of the second diffraction grating based on the determined color and the amount of light diffracted from the first diffraction grating.

11. The method according to claim 7, wherein: light formed from at least one image signal among a red image signal, a green image signal, and a blue image signal constituting the virtual image is selectively diffracted from the first diffraction grating and the second diffraction grating, light formed from image signals other than the at least one image signal among the red image signal, the green image signal, and the blue image signal is diffracted from a third diffraction grating, and Information on the shape of the fourth diffraction grating is obtained based on the characteristics of the light diffracted from the third diffraction grating.

12. The method of claim 7, further comprising identifying an executing application, in, Obtaining information about the shape of the second diffraction grating includes obtaining information about the shape of the second diffraction grating according to the identified application and the amount of light diffracted from the first diffraction grating.

Images