KR102165447B1 - Holographic display device and method for generating hologram thereof - Google Patents

Abstract

A holographic display device for generating a sub-hologram in an off-axis method, and a hologram generating method thereof, comprising: a first light source for generating first light corresponding to the viewer's left eye, and a first light source corresponding to the viewer's right eye. A second light source for generating second light, a first sub-hologram corresponding to the viewer's left eye, and a second sub-hologram corresponding to the viewer's right eye are superimposed and displayed, and the first light and the second light At the same time, the first and second light sources may be controlled to emit to the light modulator, and a control unit may be included to control the light modulator so that the first sub-hologram and the second sub-hologram are overlapped and displayed.

Description

Holographic display device and method for generating hologram thereof TECHNICAL FIELD

The present invention relates to a holographic display device, and more particularly, to a holographic display device for generating a sub-hologram in an off-axis method, and a hologram generating method thereof.

In general, Computer Generated Hologram (CGH) includes a general hologram method having a large viewing angle and a sub-hologram method limiting the viewing angle.

The general hologram method has a big problem that requires a large amount of data calculation and an ultra-high-definition panel due to a large viewing angle, whereas the sub hologram method has the advantage of solving all these problems.

Since the sub-hologram method generates only holographic information corresponding to the viewer's eye position, it is necessary to separately generate images to be observed in the viewer's left and right eyes, and send these images to each eye position.

Therefore, the sub-hologram method spatially separates and displays hologram information to be sent to the left and right eyes to a spatial light modulator, and sends optical information to the left and right eyes respectively using a beam splitter, or to the left and right eye to the spatial light modulator. The hologram information to be sent to is separated in time and displayed, and optical information is sent to the left and right eyes by using an optical deflecting device.

However, in the case of the sub-hologram method, in the case of the spatial separation method, there is a problem that the resolution of the object point displayed in the space is lowered, and in the case of the time separation, the time for displaying the object point is short, so that the brightness of the image decreases. There was a problem.

FIG. 1 is a diagram showing a general sub-hologram type holographic display device, showing a left-eye image and a right-eye image by displaying a hologram on an optical modulator in a spatial division method.

As shown in FIG. 1, a conventional device may include a light source 10, an optical modulator 20, and an image separation lens 30.

Here, the conventional device uses an image separation lens 30 such as a parallax barrier or a lenticular lens to separate the left-eye image and the right-eye image, and the pixel of the optical modulator 20 displaying a hologram is Corresponding and corresponding to the right eye image are divided from each other.

In addition, the center point SP of the sub hologram 50 may be located on an extension line between the object point OP and the center point VP of the viewing window 40.

Therefore, it can be seen that the number of center points SP of the sub-hologram 50 displayed on the optical modulator 20 is the same as the number of object points OP displayed in the 3D space.

Therefore, when the optical modulator 20 is divided into space to represent an image, the number of center points SP of the sub-hologram 50 that can be expressed by the optical modulator 20 is reduced by half, so that the object points displayed in the 3D space It can be seen that the number of OP is also reduced by half.

As a result, in the sub-hologram method, in the case of the spatial separation method, there is a problem that the resolution of the object point displayed in space is lowered, and in the case of the time separation, the time to display the object point is short, so that the brightness of the image decreases. There was a problem.

The technical problem to be achieved by an embodiment of the present invention is to superimpose a first sub-hologram corresponding to the viewer's left eye and a second sub-hologram corresponding to the viewer's right eye to display and reproduce at the same time without temporal and spatial separation. An object of the present invention is to provide a holographic display device capable of simplifying and reconstructing a 3D image based on a hologram without lowering the brightness, and a hologram generating method thereof.

The holographic display device according to an embodiment of the present invention includes a first light source for generating first light corresponding to a viewer's left eye, a second light source for generating second light corresponding to a viewer's right eye, and The first and second light sources to simultaneously emit a first sub-hologram corresponding to the left eye and a second sub-hologram corresponding to the viewer's right eye by overlapping and displaying the first and second light to the optical modulator. And a control unit for controlling the optical modulator so that the first sub-hologram and the second sub-hologram are overlapped and displayed.

Here, the controller may control the optical modulator so that the first sub-hologram and the second sub-hologram are displayed as off-axis holograms.

In addition, the controller may control the light modulator so that the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are displayed in opposite directions in the horizontal direction.

Here, the size of the off-axis for the first sub-hologram and the size of the off-axis for the second sub-hologram may be the same in the horizontal direction.

Next, the controller may control the optical modulator so that the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are displayed in the same direction in the vertical direction.

Here, the size of the off-axis for the first sub-hologram and the size of the off-axis for the second sub-hologram may be the same in the vertical direction.

In addition, the controller may control the optical modulator to complex-modulate the first sub-hologram and the second sub-hologram.

Further, the control unit may control the optical modulator to amplitude-modulate the first sub-hologram and the second sub-hologram.

In some cases, a converging lens having a viewing distance as a focal length may be disposed between the first light source or the second light source and the light modulator.

Subsequently, the present invention may further include a movement interval adjusting unit that adjusts the interval between the first light source and the second light source by moving the first light source and the second light source.

Here, the movement interval adjusting unit may vary the interval between the first light source and the second light source according to the interval between the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram.

Next, the first light source and the second light source are composed of a light source array in which a plurality of light sources are arranged, and the control unit calculates the interval between the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram. And, from the light source array, a first light source and a second light source having a distance closest to the calculated distance are searched, a first light corresponding to the left eye of the viewer is generated, and a second light corresponding to the right eye of the viewer is generated. Thus, the searched first light source and the second light source may be controlled.

In addition, the present invention may further include an imaging unit for capturing an image of a viewer, and a viewer location information acquisition unit for acquiring the position information of the viewer by detecting the position of the pupil of the viewer from the captured image of the viewer.

Next, the control unit determines the location and size of the viewing window based on the acquired location information of the user, and determines the location and size of the first and second sub-holograms based on the determined location, size, and depth information of the object point. Can be calculated.

In addition, the hologram generation method of the holographic display device according to the present invention includes the steps of capturing an image of the viewer, detecting the position of the pupil of the viewer from the image of the viewer, and the position of the pupil of the viewer from the detected pupil position of the viewer. The first and second sub-holograms based on the step of acquiring location information, the step of determining the location and size of the viewing window based on the acquired location information of the user, and the determined location, size, and depth information of the object point Calculating the position and size of, and simultaneously driving the first and second light sources to generate first light corresponding to the viewer's left eye and second light corresponding to the viewer's right eye, and Depending on the location and size of the first and second sub-holograms, the first sub-hologram corresponding to the viewer's left eye and the second sub-hologram corresponding to the viewer's right eye are overlapped and displayed.

According to an embodiment of the present invention, the first sub-hologram corresponding to the viewer's left eye and the second sub-hologram corresponding to the viewer's right eye are overlapped to display and reproduce at the same time without temporal and spatial separation, thereby reducing resolution and expression. There is an effect of restoring a 3D image by a hologram without decreasing the brightness.

In addition, the present invention does not require an additional optical lens for separating left-eye and right-eye images, so that the structure of the optical system can be simplified, thereby reducing overall cost and advantageous in miniaturization.

1 is a diagram showing a general sub-hologram type holographic display device
2 is a block diagram showing a holographic display device according to a first embodiment of the present invention
3 is a block diagram showing a holographic display device according to a second embodiment of the present invention
4 is a diagram showing a holographic display device constituting a complex hologram
5 is a view showing the viewing window of FIG. 4
6 is a diagram showing a holographic display device constituting an amplitude hologram
7 is a view showing the viewing window of FIG. 6
8 is a block diagram showing a holographic display device according to a third embodiment of the present invention
9 and 10 are diagrams for explaining a method of adjusting an interval between a first light source and a second light source
11 is a flowchart illustrating a hologram generation method of a holographic display device according to the present invention
12 is a diagram showing an input image for generating a hologram
13 is a diagram showing a reproduction image based on a complex hologram
14 is a diagram showing a reproduced image by an amplitude hologram

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The suffixes "module" and "unit" for the constituent elements used in the following description are simply given in consideration of ease of writing in the present specification, and the "module" and "unit" may be used interchangeably with each other.

Further, embodiments of the present invention will be described in detail with reference to the accompanying drawings and contents described in the accompanying drawings, but the present invention is not limited or limited by the embodiments.

The terms used in the present specification have selected general terms that are currently widely used as possible while considering functions in the present invention, but this may vary according to the intention or custom of a technician working in the art, or the emergence of new technologies. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning will be described in the description of the corresponding invention. Therefore, it should be noted that terms used in the present specification should be interpreted based on the actual meaning of the term and the entire contents of the present specification, not a simple name of the term.

The holographic display device described herein may be included in a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, and the like. .

However, it will be readily apparent to those skilled in the art that the configuration of the holographic display device according to the embodiment described herein may be applied to a mobile terminal, a fixed terminal such as a digital TV, a desktop computer, and the like.

2 is a block diagram showing a holographic display device according to a first embodiment of the present invention, and FIG. 3 is a block diagram showing a holographic display device according to a second embodiment of the present invention.

2 and 3, the holographic display device of the present invention includes a light emitting unit 100 including a first light source 110 and a second light source 120, a light modulator 200, and a control unit. It may include (300).

And, additionally, it may further include an imaging unit 400 and a viewer location information acquisition unit 500.

Here, the first light source 110 may generate first light corresponding to the viewer's left eye, and the second light source 120 may generate second light corresponding to the viewer's right eye.

In addition, when the first light source 110 and the second light source 120 generate reference light for image recording, the reference light passes through the entire area of the light modulator 200 and converges to a point at the viewing distance position. It can be a spherical file.

In this reference light, even when the pixel size of the optical modulator 200 is large and the diffraction angle by the pixel itself is not large, all information coming from the entire area of the optical modulator 200 can be viewed at the viewer's eye position. It can play a role of making.

Therefore, in order to form such a reference light, a converging lens may be further added and installed between the light emitting unit 100 and the light modulating unit 200.

In addition, when the first light source 110 and the second light source 120 generate object light for image reproduction, the object light may be formed as first or second order diffracted light to avoid DC noise. .

Here, the angle formed by the first or second order diffracted light with respect to the reference light can be controlled by adjusting the diffraction grating interval of the hologram.

In addition, the optical modulator 200 may overlap and display a first sub-hologram corresponding to the viewer's left eye and a second sub-hologram corresponding to the viewer's right eye.

Here, the sub-hologram may be generated in an area that meets the surface of the light modulator 200 by transmitting an object point from a viewing window of a certain size formed at a position of one eye of the viewer.

The center point, the object point, and the center point VP of the viewing window of the sub-hologram generated in the light modulator 200 may be located on the same line.

In addition, the sub-hologram has information for displaying an object point corresponding to the position of one eye of the viewer in the display area of the optical modulator 200.

Accordingly, the light modulator 200 includes a first sub-hologram corresponding to the viewer's left eye and a viewer from the first light generated by the first light source 110 and the second light generated by the second light source 120. The second sub-hologram corresponding to the right eye of may be overlapped and displayed.

Subsequently, a first viewing window 210 corresponding to the first sub-hologram may be formed at the viewer's left eye position, and a second viewing window 220 corresponding to the second sub-hologram may be formed at the viewer's right eye position. have.

Here, the first sub-hologram and the second sub-hologram may be off-axis holograms.

In this case, the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are opposite to each other in the horizontal direction, and the off-axis size for the first sub-hologram and the off-axis size for the second sub-hologram May be identical to each other in the horizontal direction.

In some cases, the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are the same directions in the vertical direction, and the off-axis size for the first sub-hologram and the off-axis direction for the second sub-hologram The axis sizes may be identical to each other in the vertical direction.

Further, the first sub-hologram and the second sub-hologram are complex-modulated or amplitude-modulated, and may have only a complex value or a complex number of real values.

Here, in the case of a complex hologram having only a complex number, in order to display this value on the optical modulator 200, it is a value that can be displayed in the optical modulator 200 according to the modulation characteristics of the optical modulator 200. It can be converted and displayed.

For example, when a complex hologram having only a complex number is displayed using the optical modulator 200 of an amplitude modulation method, three adjacent pixels form one hologram pixel, and the Burkhardt encoding method is used. Thus, it is possible to represent the complex value of the hologram with the amplitude values of three pixels.

In addition, when a complex hologram having only a complex number is displayed by using the optical modulator 200 of the phase modulation method, a two phase encoding method in which two adjacent pixels form one hologram pixel may be used. have.

In addition, when the first sub-hologram and the second sub-hologram are complex-modulated, a conjugate image for the first-order diffracted light is not generated. Therefore, when the off-axis direction is set in reverse, the first and second sub-holograms for the same light source The image may be separated from the sub-hologram in which the second sub-hologram is overlapped.

In addition, when the first sub-hologram and the second sub-hologram are amplitude modulated, the real value of the complex number is the amplitude value, so when using the optical modulator 200, which is an amplitude modulation method, the values can be quantized as they are. have.

Accordingly, the optical modulator 200 of the present invention may use one capable of displaying holographic data expressed as a complex number, or a one capable of displaying by converting complex data into a combination of amplitude or phase data.

Next, the controller 300 controls the first and second light sources 110 and 120 to simultaneously emit the first light and the second light to the light modulator 200, and the first sub-hologram and the second sub The optical modulator 200 may be controlled so that the holograms are overlapped and displayed.

In addition, the controller 300 may control the optical modulator 200 to display the first sub-hologram and the second sub-hologram as off-axis holograms.

Here, the controller 300 may control the optical modulator so that the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are displayed in opposite directions in the horizontal direction.

In this case, the size of the off-axis for the first sub-hologram and the size of the off-axis for the second sub-hologram may be the same in the horizontal direction.

In some cases, the controller 300 may control the optical modulator 200 so that the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are displayed in the same direction in the vertical direction. May be.

In this case, the off-axis size for the first sub-hologram and the off-axis size for the second sub-hologram may be the same in the vertical direction.

Also, the controller 300 may control the optical modulator 200 to complex-modulate the first sub-hologram and the second sub-hologram.

In some cases, the controller 300 may control the optical modulator 200 to amplitude-modulate the first sub-hologram and the second sub-hologram.

In the present invention configured as described above, a converging lens having a viewing distance as a focal length may be disposed between the first light source 110 or the second light source 120 and the light modulator 200.

Here, the reason for arranging the converging lens is that even when the pixel size of the optical modulator 200 is large and the diffraction angle by the pixel itself is not large, at the position of the viewer's eye, from the total area of the optical modulator 200 This is to create a reference light that allows you to see all the information that comes.

In this case, the reference light may pass through the entire area of the light modulator 200 and may be a spherical file that converges to a point at a viewing distance position.

For example, the converging lens may be at least one of a block lens, a fresnel lens, and a diffractive optical element (DOE).

In addition, the imaging unit 400 may capture an image of a viewer, and the viewer location information acquisition unit 500 may acquire the viewer's location information by detecting the viewer's pupil position from the captured viewer's image.

Subsequently, the controller 300 determines the positions of the first and second viewing windows 210 and 220 based on the acquired location information of the user, and determines the positions of the first and second viewing windows 210 and 220 And based on the depth information of the object point, the position and size of the first and second sub-holograms may be calculated.

Accordingly, the first and second light sources so that the central point VP of the first viewing window 210 is off-axis from the viewer's left eye, and the central point VP of the second viewing window 210 is off-axis from the viewer's right eye. The distance between (110, 120) is adjusted so that the first and second diffracted lights of the first and second viewing windows 210 and 220 are separated by the distance between the viewer's left and right eyes.

Here, in order to adjust the interval between the first and second light sources 110 and 120, the first and second light sources 110 and 120 are moved directly, and from a plurality of fixedly arranged light sources, the corresponding A fixing method for finding the first and second light sources 110 and 120 having an interval may be used.

As shown in FIG. 3, in the case of the movement method, the first light source 110 and the second light source 120 are moved to adjust the distance between the first light source 110 and the second light source 120. The spacing adjustment unit 600 may be further disposed.

Here, the movement interval adjusting unit 600 determines the interval between the first light source 110 and the second light source 120, the interval between the first diffracted light of the first sub-hologram and the first diffracted light of the second sub-hologram. Depending on, it can be variable.

In this case, an interval between the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram may be the same as the interval between the viewer's left and right eyes.

In addition, as shown in FIG. 2, in the case of a fixed method, the first light source 110 and the second light source 120 may be configured as a light source array in which a plurality of light sources are disposed.

Here, the control unit 300 calculates an interval between the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram, and the first light source having an interval closest to the calculated interval from the light source array The searched first light source 110 and the first light source 110 are searched for 110 and the second light source 120 to generate a first light corresponding to the viewer's left eye, and to generate a second light corresponding to the viewer's right eye. 2 The light source 120 can be controlled.

As described above, the present invention superimposes the first sub-hologram corresponding to the viewer's left eye and the second sub-hologram corresponding to the viewer's right eye, and displays and reproduces them at the same time without temporal and spatial separation. It is possible to reconstruct a 3D image by hologram without deterioration.

In addition, the present invention does not require an additional optical lens for separating left-eye and right-eye images, so that the structure of the optical system can be simplified, thereby reducing overall cost and advantageous in miniaturization.

4 is a diagram illustrating a holographic display device constituting a complex hologram.

As shown in FIG. 4, the first light source 110 generates first light corresponding to the viewer's left eye, and the second light source 120 generates second light corresponding to the viewer's right eye. have.

In addition, the optical modulator 200 may overlap and display a first sub-hologram corresponding to the viewer's left eye and a second sub-hologram corresponding to the viewer's right eye.

Here, a first viewing window 210 corresponding to the first sub-hologram may be formed at the viewer's left eye position, and a second viewing window 220 corresponding to the second sub-hologram may be formed at the viewer's right eye position. have.

At this time, the first sub-hologram is an off-axis hologram in which the center point (VP) of the first viewing window 210 formed at the position of the viewer's left eye is off-axis with respect to the center of the viewer's left eye, and the second sub The hologram may be an off-axis hologram in which the center point VP of the second viewing window 220 formed at the viewer's right eye position is off-axis with respect to the viewer's right eye center.

Accordingly, the first and second sub-holograms are complex holograms having a complex number, and the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are opposite to each other in the horizontal direction, and the first The off-axis size for the sub-hologram and the off-axis size for the second sub-hologram may be the same in the horizontal direction.

For example, in the first viewing window 210 and the second viewing window 220, when viewed from a viewer's point of view, a first sub-hologram corresponding to the viewer's left eye, from left to right, is -1 order, 0 The second sub-holograms are displayed in the order of the first and second diffracted lights, and corresponding to the right eye of the viewer, from left to right, and may be displayed in the order of first order, zero order, and -first order diffracted light.

At this time, the first-order diffracted light of the first sub-hologram may be displayed at the position of the viewer's left eye, and the first-order diffracted light of the second sub-hologram may be displayed at the position of the viewer's right eye.

Accordingly, the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram must be displayed so as to be spaced apart from the left and right eyes of the viewer.

Therefore, the interval between the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram can be adjusted by adjusting the distance between the first light source 110 and the second light source 120.

As described above, the present invention forms a complex hologram in this manner, so that the left-eye image and the right-eye image can be separated without temporal and spatial separation by using an additional optical lens, so that the 3D image by hologram can be reproduced without deterioration in resolution and brightness. And simplify the structure of the overall optical system.

5 is a view showing the viewing window of FIG. 4.

As shown in FIG. 5, a first viewing window 210 corresponding to the first sub-hologram is formed at the viewer's left eye position, and a second viewing window corresponding to the second sub-hologram ( 220) can be formed.

Here, the first sub-hologram is an off-axis hologram in which the center point VP of the first viewing window 210 formed at the viewer's left eye position is off-axis with respect to the viewer's left eye center, and the second sub-hologram is the viewer's The center point VP of the second viewing window 220 formed at the right eye position may be an off-axis hologram that is off-axis with respect to the center of the viewer's right eye.

At this time, the center point VP of the first viewing window 210 is off-axis in the first direction from the center of the left eye of the viewer, and the center point VP of the second viewing window 210 is first from the center of the viewer's right eye. It is off-axis in a second direction opposite to the direction.

Here, the off-axis size of the central point VP of the first viewing window 210 and the off-axis size of the central point VP of the second viewing window 220 may be the same.

That is, the direction of the off-axis 240 with respect to the first sub-hologram and the direction of the off-axis 230 with respect to the second sub-hologram are opposite to each other in the horizontal direction.

In addition, the size of the off-axis 240 for the first sub-hologram and the size of the off-axis 230 for the second sub-hologram may be the same in the horizontal direction.

For example, in the first viewing window 210, the left-eye image is displayed in the first direction, in the order of 1st, 0th, and -1st diffracted light, and the second viewing window 210 shows the right-eye image. , In the second direction, may be displayed in the order of 1st, 0th, and -1st diffracted light.

At this time, the first-order diffracted light of the left-eye image may be displayed at the position of the viewer's left eye, and the first-order diffracted light of the right-eye image may be displayed at the position of the viewer's right eye.

Accordingly, the first-order diffracted light of the left-eye image and the first-order diffracted light of the right-eye image must be displayed so as to be separated by a distance between the left and right eyes of the viewer.

6 is a diagram illustrating a holographic display device constituting an amplitude hologram.

6, the first light source 110 generates a first light corresponding to the viewer's left eye, and the second light source 120 generates a second light corresponding to the viewer's right eye. have.

In addition, the optical modulator 200 may overlap and display a first sub-hologram corresponding to the viewer's left eye and a second sub-hologram corresponding to the viewer's right eye.

Here, a first viewing window 210 corresponding to the first sub-hologram may be formed at the viewer's left eye position, and a second viewing window 220 corresponding to the second sub-hologram may be formed at the viewer's right eye position. have.

At this time, the first sub-hologram is an off-axis hologram in which the center point (VP) of the first viewing window 210 formed at the position of the viewer's left eye is off-axis with respect to the center of the viewer's left eye, and the second sub The hologram may be an off-axis hologram in which the center point VP of the second viewing window 220 formed at the viewer's right eye position is off-axis with respect to the viewer's right eye center.

Accordingly, the first and second sub-holograms are amplitude holograms having a complex-numbered real value, and the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are horizontally opposite to each other, The off-axis size for the first sub-hologram and the off-axis size for the second sub-hologram may be the same in the horizontal direction.

In addition, the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are the same in the vertical direction, and the off-axis size for the first sub-hologram and the off-axis size for the second sub-hologram May be identical to each other in the vertical direction.

For example, when viewed from a viewer's point of view, the first viewing window 210 has a first sub-hologram corresponding to the viewer's left eye, in a horizontal direction, from left to right, -1st, 0th, and 1st. It is displayed in the order of diffracted light, and may be displayed in the order of the vertical direction, the upper to the lower direction, the first order, the zero order, and the -first order diffracted light.

And, in the second viewing window 220, when viewed from a viewer's point of view, a second sub-hologram corresponding to the viewer's right eye is displayed from left to right, in the order of first order, zero order, and -1 order diffracted light. , In the vertical direction, from the top to the bottom, the first order, the zero order, and the -1 order diffracted light may be displayed in the order.

At this time, the first-order diffracted light of the first sub-hologram may be displayed at the position of the viewer's left eye, and the first-order diffracted light of the second sub-hologram may be displayed at the position of the viewer's right eye.

Accordingly, the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram must be displayed so as to be spaced apart from the left and right eyes of the viewer.

Therefore, the interval between the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram can be adjusted by adjusting the distance between the first light source 110 and the second light source 120.

As described above, the present invention forms an amplitude hologram in this manner, so that the left-eye image and the right-eye image can be separated without temporal and spatial separation by using an additional optical lens, so that the 3D image by hologram can be reproduced without deterioration in resolution and brightness. And simplify the structure of the overall optical system.

7 is a view showing the viewing window of FIG. 6.

As shown in FIG. 7, a first viewing window 210 corresponding to the first sub-hologram is formed in the viewer's left eye position, and a second viewing window corresponding to the second sub-hologram ( 220) can be formed.

Here, the first sub-hologram is an off-axis hologram in which the center point VP of the first viewing window 210 formed at the viewer's left eye position is off-axis with respect to the viewer's left eye center, and the second sub-hologram is the viewer's The center point VP of the second viewing window 220 formed at the right eye position may be an off-axis hologram that is off-axis with respect to the center of the viewer's right eye.

At this time, the center point VP of the first viewing window 210 is off-axis in the first direction from the center of the left eye of the viewer, and the center point VP of the second viewing window 210 is first from the center of the viewer's right eye. It is off-axis in a second direction opposite to the direction.

Here, the off-axis size of the central point VP of the first viewing window 210 and the off-axis size of the central point VP of the second viewing window 220 may be the same.

In addition, the center point VP of the first viewing window 210 is off-axis in a third direction from the center of the left eye of the viewer, and the center point VP of the second viewing window 210 is also third from the center of the viewer's right eye. It is off-axis in the same direction.

Here, the off-axis size of the central point VP of the first viewing window 210 and the off-axis size of the central point VP of the second viewing window 220 may be the same.

That is, the directions of the off-axis 240 and 260 with respect to the first sub-hologram and the direction of the off-axis 230 and 250 with respect to the second sub-hologram are opposite to each other in the horizontal direction and the same in the vertical direction.

In addition, the size of the off-axis 240 and 260 for the first sub-hologram and the size of the off-axis 230 and 250 for the second sub-hologram may be the same in the horizontal direction and the vertical direction.

For example, in the first viewing window 210, the left eye image is displayed in the order of the first horizontal direction, the first order, the zero order, the -1 order diffracted light, and the first vertical direction, the first order, the zero order , Displayed in the order of -1st order diffracted light, and in the second viewing window 210, the right-eye image is displayed in a second horizontal direction opposite to the first horizontal direction, in the order of 1st, 0th, and -1st diffracted light. Is displayed, and may be displayed in the first vertical direction, in the order of 1st, 0th, and -1st diffracted light.

At this time, the first-order diffracted light of the left-eye image may be displayed at the position of the viewer's left eye, and the first-order diffracted light of the right-eye image may be displayed at the position of the viewer's right eye.

Accordingly, the first-order diffracted light of the left-eye image and the first-order diffracted light of the right-eye image must be displayed so as to be separated by a distance between the left and right eyes of the viewer.

8 is a block diagram showing a holographic display device according to a third embodiment of the present invention.

As shown in FIG. 8, the holographic display device of the present invention includes a light emitting unit 100 including a first light source 110 and a second light source 120, a converging lens 700, and a light modulator 200. ) And a control unit 300.

And, additionally, it may further include an imaging unit 400 and a viewer location information acquisition unit 500.

The third embodiment of the present invention is the same as the first and second embodiments of the present invention, except that the converging lens 700 is added, and a detailed description thereof will be omitted.

Here, between the light-emitting unit 100 including the first light source 110 or the second light source 120 and the light modulator 200, a converging lens having a viewing distance as a focal length may be disposed.

Here, the reason for arranging the converging lens is that even when the pixel size of the optical modulator 200 is large and the diffraction angle by the pixel itself is not large, at the position of the viewer's eye, from the total area of the optical modulator 200 This is to create a reference light that allows you to see all the information that comes.

In this case, the reference light may pass through the entire area of the light modulator 200 and may be a spherical file that converges to a point at a viewing distance position.

For example, the converging lens may be at least one of a block lens, a fresnel lens, and a diffractive optical element (DOE).

In addition, the converging lens 700 and the optical modulator 200 may be disposed apart by a predetermined distance d.

In some cases, the converging lens 700 may be moved according to a driving signal of the controller 300 to adjust the distance d between the converging lens 700 and the optical modulator 200.

9 and 10 are diagrams for explaining a method of adjusting a distance between a first light source and a second light source, and FIG. 9 is a moving method, and FIG. 10 is a fixed method.

9 and 10, the controller 300 determines the positions of the first and second viewing windows 210 and 220 based on the acquired location information of the user, and determines the first and second viewing windows. Based on the location of the viewing windows 210 and 220 and the depth information of the object point, the location and size of the first and second sub-holograms may be calculated.

Accordingly, the first and second light sources so that the central point VP of the first viewing window 210 is off-axis from the viewer's left eye, and the central point VP of the second viewing window 210 is off-axis from the viewer's right eye. The distance between (110, 120) is adjusted so that the first and second diffracted lights of the first and second viewing windows 210 and 220 are separated by the distance between the viewer's left and right eyes.

Here, in order to adjust the interval between the first and second light sources 110 and 120, as shown in FIG. 9, a movement method of directly moving the first and second light sources 110 and 120, and as shown in FIG. 10, A fixing method for finding the first and second light sources 110 and 120 having corresponding intervals from a plurality of fixedly arranged light sources may be used.

As shown in FIG. 9, in the case of the movement method, the movement interval adjustment unit 600 moves the first light source 110 and the second light source 120 according to a control signal from the control unit 300, The distance d11 between the light source 110 and the second light source 120 may be adjusted.

That is, the movement interval adjusting unit 600 determines the distance d11 between the first light source 110 and the second light source 120, between the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram. Depending on the interval d12, it can be variable.

In this case, the distance d12 between the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram may be the same as the distance between the viewer's left and right eyes.

In addition, as shown in FIG. 10, in the case of a fixed method, the first light source 110 and the second light source 120 may be included in the light source array 150 in which a plurality of light sources are disposed.

Here, the control unit 300 calculates an interval d12 between the first order diffracted light of the first sub-hologram and the first order diffracted light of the second sub-hologram, and has an interval d11 closest to the calculated interval d12 from the light source array. The first light source 110 and the second light source 120 are searched for, and the searched first light source 110 and the second light source 120 are controlled to generate first light corresponding to the viewer's left eye. , It is possible to generate a second light corresponding to the viewer's right eye.

11 is a flowchart illustrating a hologram generation method of a holographic display device according to the present invention.

As shown in Fig. 11, first, the imaging unit captures an image of a viewer (S10).

In addition, the viewer location information acquisition unit may detect the viewer's pupil position from the captured viewer's image (S20), and obtain the viewer's position information from the detected pupil position of the viewer (S30).

Next, the control unit determines the location and size of the viewing window based on the acquired location information of the user (S40), and based on the determined location, size, and depth information of the object point, the location of the first and second sub-holograms And the size can be calculated (S50)

In addition, the control unit determines whether the current distance between the first light source and the second light source corresponds to a pre-calculated distance value between the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram.

If the current distance between the first light source and the second light source does not correspond to the calculated spacing value, the control unit determines the first light source so that the distance between the first light source and the second light source corresponds to the calculated spacing value. And move the second light source.

Next, the controller may simultaneously drive the first and second light sources to generate first light corresponding to the viewer's left eye and second light corresponding to the viewer's right eye (S60).

In addition, the controller may overlap and display the first sub-hologram corresponding to the viewer's left eye and the second sub-hologram corresponding to the viewer's right eye according to the calculated positions and sizes of the first and second sub-holograms. (S70)

Here, the first sub-hologram and the second sub-hologram may be displayed as off-axis holograms.

In this case, the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are opposite to each other in the horizontal direction, and the off-axis size for the first sub-hologram and the off-axis size for the second sub-hologram May be identical to each other in the horizontal direction.

In addition, the off-axis direction for the first sub-hologram and the off-axis direction for the second sub-hologram are the same direction in the vertical direction, and the off-axis size for the first sub-hologram and the off-axis size for the second sub-hologram May be identical to each other in the vertical direction.

12 is a diagram showing an input image for generating a hologram, FIG. 13 is a diagram showing a reproduction image based on a complex hologram, and FIG. 14 is a diagram showing a reproduction image using an amplitude hologram.

If the input image corresponding to the viewer's left eye and the right eye is an image as shown in FIG. 12, a hologram calculation using the input image may be performed in the form of a complex hologram or an amplitude hologram.

Here, one hologram is created by overlapping the holograms corresponding to the left eye and the right eye, and if the generated hologram is a complex hologram, if the off-axis value is applied in the horizontal direction in opposite directions, the reproduced image is numerically Is calculated by the method.

As described above, when the calculated hologram is simultaneously irradiated with light sources corresponding to the left and right eyes, a reproduced image formed on the retina of the viewer's left and right eyes is shown in FIG. 13.

In this case, the image is reversed in the vertical, left and right directions.

And, one hologram is created by overlapping the holograms corresponding to the left eye and the right eye, and if the generated hologram is an amplitude hologram, the off-axis value is applied in the horizontal direction in opposite directions, and the off-axis value in the vertical direction When applied in the same direction to each other, the reproduced image is calculated numerically.

In this way, when the calculated hologram is simultaneously irradiated with light sources corresponding to the left and right eyes, a reproduced image formed on the retina of the viewer's left and right eyes is shown in FIG. 14.

In this case, the image is reversed in the vertical, left and right directions.

That is, in both cases, it can be seen that only the left image is played in the left eye and only the right image is played in the right eye.

As described above, the present invention superimposes the first sub-hologram corresponding to the viewer's left eye and the second sub-hologram corresponding to the viewer's right eye, and displays and reproduces them at the same time without temporal and spatial separation. It is possible to reconstruct a 3D image by hologram without deterioration.

In addition, the present invention does not require an additional optical lens for separating left-eye and right-eye images, so that the structure of the optical system can be simplified, thereby reducing overall cost and advantageous in miniaturization.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and is generally used in the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Of course, various modifications may be implemented by those skilled in the art, and these modifications should not be understood individually from the technical idea or prospect of the present invention.

100: light emitting unit 110: first light source
120: second light source 200: light modulator
210: first viewing window 220: second viewing window
300: control unit 400: imaging unit
500: viewer location information acquisition unit

Claims (20)

A first light source for generating first light corresponding to the viewer's left eye;
A second light source that generates second light corresponding to the viewer's right eye and is different from the first light source;
An optical modulator configured to overlap and display a first sub-hologram corresponding to the viewer's left eye and a second sub-hologram corresponding to the viewer's right eye; And,
A control unit that controls the first and second light sources to simultaneously emit the first and second light to the light modulator, and controls the light modulator so that the first sub-hologram and the second sub-hologram overlap and display
Including,
The control unit,
The first light source and the second light source generate reference light for image recording and object light for image reproduction, and the object light is controlled to be formed as first or second order diffracted light
The first or second diffracted light forms a certain angle with respect to the reference light,
The control unit controls the light modulator to display the first sub-hologram and the second sub-hologram as an off-axis hologram. delete The method of claim 1, wherein the controller controls the optical modulator so that an off-axis direction for the first sub-hologram and an off-axis direction for the second sub-hologram are displayed in opposite directions in a horizontal direction. Holographic display device characterized by. The holographic display apparatus of claim 3, wherein an off-axis size for the first sub-hologram and an off-axis size for the second sub-hologram are the same in a horizontal direction. The method of claim 1, wherein the control unit controls the light modulator so that an off-axis direction for the first sub-hologram and an off-axis direction for the second sub-hologram are displayed in the same direction in a vertical direction. Holographic display device characterized by. The holographic display apparatus of claim 5, wherein an off-axis size for the first sub-hologram and an off-axis size for the second sub-hologram are the same in a vertical direction. The holographic display apparatus of claim 1, wherein the controller controls the optical modulator to complex-modulate the first sub-hologram and the second sub-hologram. The holographic display apparatus of claim 1, wherein the controller controls the optical modulator to amplitude-modulate the first sub-hologram and the second sub-hologram. The holographic display apparatus of claim 1, wherein a converging lens having a viewing distance as a focal length is disposed between the first light source or the second light source and the light modulator. The holographic display apparatus of claim 9, wherein the converging lens is at least one of a block lens, a fresnel lens, and a diffractive optical element (DOE). The holographic display apparatus of claim 1, further comprising a movement interval adjusting unit configured to move the first light source and the second light source to adjust a distance between the first light source and the second light source. 12. The method of claim 11, wherein the movement interval adjusting unit adjusts the distance between the first light source and the second light source to a distance between the first order diffracted light of the first sub-hologram and the first order diffracted light of the second sub hologram Accordingly, the holographic display device, characterized in that variable. The holographic display of claim 11, wherein an interval between the first order diffracted light of the first sub-hologram and the first order diffracted light of the second sub-hologram is the same as the distance between the left and right eyes of the viewer. Device. The method of claim 1, wherein the first light source and the second light source are composed of a light source array in which a plurality of light sources are disposed,
The control unit,
Calculating an interval between the first-order diffracted light of the first sub-hologram and the first-order diffracted light of the second sub-hologram,
From the light source array, a first light source and a second light source having an interval closest to the calculated interval are searched,
And controlling the searched first light source and second light source to generate first light corresponding to the viewer's left eye and second light corresponding to the viewer's right eye. The apparatus of claim 1, further comprising: an imaging unit that captures an image of the viewer; And,
And a viewer location information acquisition unit configured to detect the location of the viewer's pupil from the captured image of the viewer and obtain location information of the viewer. The method of claim 15, wherein the controller determines the location and size of the viewing window based on the acquired location information of the user, and based on the determined location, size, and depth information of the object point, the first and second 2 Holographic display device, characterized in that calculating the position and size of the sub-hologram. In the hologram generation method of a holographic display device comprising first and second light sources and a light modulator,
Capturing an image of a viewer;
Detecting a pupil position of the viewer from the captured image of the viewer;
Obtaining location information of the viewer from the detected pupil location of the viewer;
Determining the location and size of the viewing window based on the acquired location information of the viewer;
Calculating the positions and sizes of the first and second sub-holograms based on the determined location, size, and depth information of the object point;
Generating a first light corresponding to the left eye of the viewer and a second light corresponding to the right eye of the viewer and different from the first light by simultaneously driving the first and second light sources;
In accordance with the calculated positions and sizes of the first and second sub-holograms, displaying a first sub-hologram corresponding to the viewer's left eye and a second sub-hologram corresponding to the viewer's right eye by overlapping each other,
The first light source and the second light source generate reference light for image recording and object light for image reproduction, and the object light is formed of first or second order diffracted light,
The first or second diffracted light forms a certain angle with respect to the reference light,
The first sub-hologram and the second sub-hologram are displayed as off-axis holograms
Hologram generation method of a holographic display device, characterized in that. delete The method of claim 17, wherein an off-axis direction for the first sub-hologram and an off-axis direction for the second sub-hologram are opposite to each other in a horizontal direction, and an off-axis size for the first sub-hologram and the first 2 A hologram generation method of a holographic display device, characterized in that the off-axis sizes for the sub-holograms are the same in a horizontal direction. The method of claim 17, wherein an off-axis direction for the first sub-hologram and an off-axis direction for the second sub-hologram are the same in a vertical direction, and an off-axis size for the first sub-hologram and the first 2 A hologram generation method of a holographic display device, characterized in that the off-axis sizes for the sub-holograms are the same in a vertical direction.

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