KR20160116500A - Manufacturing method of holographic optical elements using spatial light modulator - Google Patents

Manufacturing method of holographic optical elements using spatial light modulator Download PDF

Info

Publication number
KR20160116500A
KR20160116500A KR1020150044303A KR20150044303A KR20160116500A KR 20160116500 A KR20160116500 A KR 20160116500A KR 1020150044303 A KR1020150044303 A KR 1020150044303A KR 20150044303 A KR20150044303 A KR 20150044303A KR 20160116500 A KR20160116500 A KR 20160116500A
Authority
KR
South Korea
Prior art keywords
exposure
digital image
spatial light
light
light modulator
Prior art date
Application number
KR1020150044303A
Other languages
Korean (ko)
Other versions
KR101669825B1 (en
Inventor
옥광호
김대현
Original Assignee
주식회사 미래기술연구소
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 주식회사 미래기술연구소 filed Critical 주식회사 미래기술연구소
Priority to KR1020150044303A priority Critical patent/KR101669825B1/en
Publication of KR20160116500A publication Critical patent/KR20160116500A/en
Application granted granted Critical
Publication of KR101669825B1 publication Critical patent/KR101669825B1/en

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/04—Processes or apparatus for producing holograms
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/02—Details of features involved during the holographic process; Replication of holograms without interference recording
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/04—Processes or apparatus for producing holograms
    • G03H1/0402—Recording geometries or arrangements
    • G03H1/041—Optical element in the object space affecting the object beam, not otherwise provided for
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/22—Processes or apparatus for obtaining an optical image from holograms

Abstract

The present invention relates to a method to manufacture a holographic optical element by using a spatial optical modulator. The method comprises the steps of: preparing a digital image in which an exposure pattern of an exposure/non-exposure is recorded with a pixel unit of a spatial optical modulator (20); dividing the digital image into a plurality of (X, Y)d coordinate having a predetermined area and to store individual digital image (Xn, Yn)d of divided coordinate in a control apparatus (1); mounting a photo plate (P) on a work board (10); transmitting a control signal for the exposure pattern of the exposure/non-exposure recorded in the first digital image (X1, Y1)d to the spatial optical modulator (20) and recording the exposure pattern of the first digital image (X1, Y1)d in the (X1, Y1)p of a photo plate (P) by using light generated by a light generator (30); and successively transmitting a control signal for the exposure pattern of the exposure/non-exposure individually recorded in a second, a third, ..., an n^th digital image {(X2, Y2,)d, (X3, Y3)d, ..., (Xn, Yn)d} to the spatial optical modulator and successively exposing the exposure pattern of the second, the third, ..., the n^th digital image {(X2, Y2,)d, (X3, Y3)d, ..., (Xn, Yn)d} of the photo plate (p) by using the light generated by the light generator (30).

Description

Technical Field [0001] The present invention relates to a holographic optical element using a spatial light modulator,

The present invention relates to a method of manufacturing a holographic optical element, and more particularly, to a method of manufacturing a holographic optical element by using a spatial light modulator provided with a large number of pixels so as to simultaneously expose a certain region of the photoresist with an intended exposure pattern, A holographic optical element having an intended exposure pattern can be realized, and a holographic optical element having a large diameter can be manufactured very easily.

Holographic optical elements (or HOEs) are holograms designed to act as optical components, such as lenses, diffusers, and reflectors, or to perform the combined function of these optical components.

Such a holographic optical element is advantageous in that the optical apparatus itself can be miniaturized or simplified and is used as a component in a special purpose image optical apparatus such as a head up display (HUD) or a helmet mounted display (HMD) A light quantity inductive element in which a holographic optical element having a plate shape is sandwiched between two-layer glass in power generation has been proposed.

FIG. 3 shows a conventional method of manufacturing a holographic optical element. First, a photo plate P having a photoresist film such as a photographic plate is placed on the work plate 1. When the photo plate P is placed on the work plate 1, the light generating device 10 is operated. The generated light is diffracted by the grating 14 via the mirror 12 and then focused on one side of the photo plate P through the focusing lens 16. [

At this time, among the light diffracted by the grating 14, the remaining diffracted light except the + 1st-order diffracted light and the -1st-order diffracted light is removed by the iris 15 located under the grating 14. Therefore, focusing on the photo plate P by the focusing lens 16 is an interference fringe by + 1st-order diffracted light and -1st-order diffracted light passing through the iris 15, and this interference fringe pattern is reflected by the photo plate P). 4 is a cross-sectional view showing an exposure pattern of the holographic optical element, wherein the valley portion is an exposure region.

Since the holographic optical element is a means using light, the size of the interference fringe formed by focusing on the photographic plate P through the condenser lens 16 should be at least a pixel unit, and function as an optical element. If the size of the photo plate on which the interference fringes are to be recorded is about 100 mm in width and about 100 mm in length and 1 pixel is about 1 m in width and about 1 m in length, Or more. Due to such a problem, the holographic optical element is still applied only to a specific field, and is not widely applied to other industrial fields.

Korean Patent No. 0227179, Korean Patent No. 0590519, Korean Patent Publication No. 2013-0022081

It is an object of the present invention to provide a holographic optical element having a uniform quality and a holographic optical element having a uniform quality, To provide a way to do so.

In order to achieve the above object, the present invention provides a lithographic apparatus including a work plate, a spatial light modulator disposed at a predetermined distance vertically above the work plate, A beam splitter 22 located between the working plate 10 and the spatial light modulator 20 and sharing an optical axis with the light generating device 30; An optical system including a focusing lens 26 positioned between the spatial light modulator 20 and the optical axis of the spatial light modulator 20 and a control device 1 for controlling the spatial light modulator 20 and the light generating device 30, ≪ / RTI > Preparing a digital image including an exposure pattern of exposure / non-exposure in units of pixels of the spatial light modulator 20; Dividing the digital image into a plurality of (X, Y) d coordinates having a predetermined area, and storing the individual digital images (Xn, Yn) d of the respective divided coordinates in the control device (1); Placing a photo plate (P) on the upper surface of the work plate (10); A control signal for the exposure pattern of exposure / unexposed light included in the first digital image (X1, Y1) d is sent to the spatial light modulator 20 and the light generated by the light generating device 30 is sent to the beam splitter 22 And the light is reflected by the spatial light modulator 20 to reflect the light according to the exposure pattern of exposure / non-exposure included in the first digital image X1, Y1 d and then passes through the focusing lens 26 to the , Y1) p of the first digital image (X1, Y1) d; Second, 3,. . n Digital image {(X2, Y2,) d, (X3, Y3) d,. . (Xn, Yn) d} to the spatial light modulator 20, and transmits the light generated by the light generating device 30 to the beam splitter 22 And the second, third, and fourth spatial light modulators 20, respectively. . n Digital image {(X2, Y2,) d, (X3, Y3) d,. . (X2, Y2) p, (X3, Y3) p (X2, Y3) d of the phototransistor P through the focusing lens 26 after reflecting the light according to the exposure pattern of the exposure / non- ,. . (Xn, Yn) p}, respectively. . n Digital image {(X2, Y2,) d, (X3, Y3) d,. . (Xn, Yn) d} sequentially exposing the respective exposure patterns; And the present invention is characterized in that it includes the technical features.

The movement of the working plate 10 in the X and Y directions can be controlled by interlocking with each coordinate (X, Y) d of the digital image.

The present invention proposes a method of simultaneously exposing a certain region of a phototray using a spatial light modulator having a large number of pixels without exposing the photodetector in units of pixels as in the prior art, thereby producing a holographic optical element having an intended exposure pattern The time can be remarkably shortened and it is possible to manufacture the large-diameter holographic optical element very easily.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic structural view of an optical system used for manufacturing a holographic optical element according to the present invention; Fig.
2 is a schematic diagram showing an example of an exposure pattern stored in a controller according to the present invention;
3 is a schematic structural view showing a method of manufacturing a conventional holographic optical element;
4 is a schematic cross-sectional structural view of a holographic optical element;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the technical features of the present invention, A detailed description thereof will be omitted.

First, an optical system is constructed. The optical system includes a control device 1, a work plate 10, a spatial light modulator 20, a light generating device 30, and a light source device, as shown in FIG. 1, A beam splitter 22 and a focusing lens 26 as shown in FIG.

The control device 1 is a means for controlling the light generating device 30 and the spatial light modulator 20 and is provided with a data storage unit for storing the exposure pattern. The control device may be a conventional terminal equipped with a data storage unit and a control unit.

The work plate 10 is a portion on which the photo plate P is placed and the present invention is such that the work plate 10 is moved in the X and Y directions by the X and Y driving means 12 and the Y- Is not controlled. The movement of the work plate 10 is interlocked with the respective coordinates (X, Y) d of the digital image to be described later. Each of the X-axis driving means 12 and the Y-axis driving means 16 may be composed of a motor, and its driving is controlled by the control device 1. [

The spatial light modulator 20 is a device that individually controls and reflects hundreds of thousands to millions of micro mirrors integrated in a pixel unit (㎛ interval) according to an input control signal. That is, the light incident on the micro mirror which is operated by inputting the control signal is not reflected to the outside (on / unexposed), and the light incident on the micro mirror not operating due to no control signal is reflected to the outside / Exposure). The present invention utilizes a micro mirror on / off operation configuration provided in such a spatial light modulator. The spatial light modulator 20 is spaced vertically above the work plate 10 by a predetermined distance.

The light generating device 30 is made of laser light and is provided on one side of the work plate 10. Although not shown in the drawings, a filter may be provided on one side of the light generating device 30. The beam splitter 22 is a means for reflecting the light generated by the light generating device 30 and transmitting it to the spatial light modulator 20 and is located between the working plate 10 and the spatial light modulator 20, (30). The beam splits can be made of semi-transparent mirrors.

The focusing lens 26 is a means for focusing the light reflected by the spatial light modulator 20 to a certain size and is positioned between the working plate 10 and the beam splitter 22 and shares the optical axis with the spatial light modulation 20. [ do. It is preferable that the area converged by the focusing lens 26 onto the photoresist film of the photopattern P is adjusted to such an extent that at least the individual micro mirrors provided in the spatial light modulator 20 can be recognized. The area of exposure by the focusing lens 26 can be adjusted by the distance between the focusing lens 26 and the photopattern P. [ Reference numeral 24 denotes a filter.

When the optical system is constructed, a digital image including an exposure pattern of exposure / non-exposure is prepared on a pixel-by-pixel basis of the spatial light modulator 20, as shown in Fig. 2 showing an example of an exposure pattern. Here, the exposure / non-exposure corresponds to the non-operation / on of the micro mirror provided in the spatial light modulator 20, and as described above, the pixels (each pixel marked with black) The micro mirrors do not work, and the pixels in the non-exposed areas (each pixel marked in white) operate with a micro mirror. It goes without saying that such an exposure pattern can be variously changed according to a holographic optical element to be implemented.

(X, y) d coordinates of a certain area, and dividing the digital image into a plurality of divided digital images (Xn, Yn) d (x, y) To the control device (1). The (X, Y) d coordinate area may vary depending on the spatial light modulator 20 used. That is, the prepared digital image may be appropriately divided according to the number of pixels provided in the spatial light modulator.

When a separate digital image having an exposure pattern and an unexposed light pattern is stored in the control unit 1, a photo plate P is placed on the upper surface of the work plate 10. The photo plate P may be made of any one of photoresist plates widely used in related industries.

When the photo plate P is laid, a control signal for the exposure pattern of exposure / non-exposure included in the first digital image (X1, Y1) d among the individual digital images stored in the control device 1 is supplied to the spatial light modulator 20 And operates the light generating device 30. Accordingly, the light (1) generated by the light generating device 30 enters the spatial light modulator 20 through the beam splitter 22 ((2)).

When light is incident on the spatial light modulator 20 in a state in which a control signal for the exposure pattern of exposure / non-exposure included in the first digital image (X1, Y1) d is input, The mirrors are turned off / on according to the control signal for the exposure pattern, and reflect incident light (③). That is, only light incident on the micro mirrors that are inactivated according to the exposure pattern out of the light incident on the spatial light modulator 20 is reflected and emitted.

The light modulated and emitted from the spatial light valve 20 is converged to a predetermined magnitude through the focusing lens 26 to expose the (X1, Y1) p coordinate region of the photopattern P (4). Accordingly, the exposure pattern recorded in the first digital image (X1, Y1) d coordinate area is recorded in the (X1, Y1) p coordinate area of the photo plate P. If the photo plate is of the positive type, the non-operation part of the spatial light modulator forms a valley of the photo plate. If the photo plate is of the negative type, the on part of the spatial light modulator forms a valley of the photo plate (See Fig. 4). That is, it is possible to perform exposure in a pattern intended for a certain size area by a single operation.

When the exposure of the first digital image is completed, the operation of the light generating device 30 is stopped (if the separate shutter is mediated, the operation of the light generating device may not be stopped) The operation plate 10 moves due to the operation of the means 12, 16. The movement degree of the work plate 10 is interlocked with the coordinates (X, Y) d of the digital image as described above.

When the work plate 10 is moved to the next working position, a control signal for the exposure pattern of the exposed / unexposed light included in the second digital image (X2, Y2,) d is transmitted to the spatial light modulator 20, (30). The light generated in the light generating device 30 enters the spatial light modulator 20 through the beam splitter 22 in the same manner as in the first digital image and the light modulated in the spatial light modulator 20 is incident on the focusing lens 20, (X2, Y2) d coordinate area of the photographic plate P is recorded in the coordinate area of the second digital image (X2, Y2) d coordinate area.

When the exposure operation for the second digital image is completed, the work plate 10 is moved in conjunction with each coordinate (X, Y) d of the digital image, and the third, fourth,. . n digital image sequentially in the corresponding coordinate area of the photo plate P. When the exposure operation for the n-th digital image is completed, an intended exposure pattern as exemplarily shown in Fig. 2 is recorded on the photographic plate P. Fig. Thereafter, when the photo plate P is developed, a holographic optical element having an exposure pattern as shown in Fig. 2 is obtained.

As described above, in the present invention, the holographic optical element can be fabricated more rapidly because it is a method of exposing the photographic plate to a coordinate unit of a certain area using a spatial light modulator, A large-diameter holographic optical element can be manufactured very easily.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. It will be apparent that the present invention can be practiced with added features.

10: work plate 20: spatial light modulator
22: beam splitting 26: focusing lens

Claims (2)

A spatial light modulator 20 positioned vertically above and vertically above the work plate 10; a light generating device 30 provided at one side of the work plate 10; A beam splitter 22 which is located between the light source 10 and the spatial light modulator 20 and shares the optical axis with the light generating device 30 and a beam splitter 22 which is located between the working plate 10 and the beam splitter 22, A focusing lens 26 that shares an optical axis with the optical axis 20, and a control device 1 that controls the spatial light modulator 20 and the light generating device 30;
Preparing a digital image including an exposure pattern of exposure / non-exposure in units of pixels of the spatial light modulator 20;
Dividing the digital image into a plurality of (X, Y) d coordinates having a predetermined area, and storing the individual digital images (Xn, Yn) d of the respective divided coordinates in the control device (1);
Placing a photo plate (P) on the upper surface of the work plate (10);
A control signal for the exposure pattern of exposure / unexposed light included in the first digital image (X1, Y1) d is sent to the spatial light modulator 20 and the light generated by the light generating device 30 is sent to the beam splitter 22 And the light is reflected by the spatial light modulator 20 to reflect the light according to the exposure pattern of exposure / non-exposure included in the first digital image X1, Y1 d and then passes through the focusing lens 26 to the , Y1) p of the first digital image (X1, Y1) d;
Second, 3,. . n Digital image {(X2, Y2,) d, (X3, Y3) d,. . (Xn, Yn) d} to the spatial light modulator 20, and transmits the light generated by the light generating device 30 to the beam splitter 22 And the second, third, and fourth spatial light modulators 20, respectively. . n Digital image {(X2, Y2,) d, (X3, Y3) d,. . (X2, Y2) p, (X3, Y3) p (X2, Y3) d of the phototransistor P through the focusing lens 26 after reflecting the light according to the exposure pattern of the exposure / non- ,. . (Xn, Yn) p}, respectively. . n Digital image {(X2, Y2,) d, (X3, Y3) d,. . (Xn, Yn) d} sequentially exposing the respective exposure patterns;
Wherein the spatial light modulator comprises a plurality of spatial light modulators. The method according to claim 1,
Wherein the working plate (10) is moved in the X and Y directions by being interlocked with each coordinate (X, Y) d of the digital image.
KR1020150044303A 2015-03-30 2015-03-30 Manufacturing method of holographic optical elements using spatial light modulator KR101669825B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020150044303A KR101669825B1 (en) 2015-03-30 2015-03-30 Manufacturing method of holographic optical elements using spatial light modulator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020150044303A KR101669825B1 (en) 2015-03-30 2015-03-30 Manufacturing method of holographic optical elements using spatial light modulator

Publications (2)

Publication Number Publication Date
KR20160116500A true KR20160116500A (en) 2016-10-10
KR101669825B1 KR101669825B1 (en) 2016-10-27

Family

ID=57146477

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020150044303A KR101669825B1 (en) 2015-03-30 2015-03-30 Manufacturing method of holographic optical elements using spatial light modulator

Country Status (1)

Country Link
KR (1) KR101669825B1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101883235B1 (en) * 2017-06-05 2018-07-30 주식회사 미래기술연구소 Injection molding method of an outer panel having a hologram for a tail lamp of a car
KR20200048921A (en) * 2018-10-31 2020-05-08 주식회사 미래기술연구소 Manufacturing method of security hologram sticker labels

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101913270B1 (en) * 2016-12-20 2018-10-30 주식회사 미래기술연구소 Manufacturing method of hologram for anti-counterfeit having arbitarary hypertext
KR20230133114A (en) 2022-03-10 2023-09-19 주식회사 미래기술연구소 Manufactuaring method of hologram reproducing apparatus through computer generated holography with depth information and lighting angle

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100227179B1 (en) 1997-04-11 1999-10-15 박호군 The manufacture apparatus for reflection type holographic optic element of high quality
US6281993B1 (en) * 1998-03-30 2001-08-28 International Business Machines Corporation Phase shifting element for optical information processing storing systems
EP0934540B1 (en) * 1996-10-28 2004-12-22 Pacific Holographics, Inc Apparatus and method for generating diffractive element using liquid crystal display
JP2006099880A (en) * 2004-09-29 2006-04-13 Toshiba Corp Hologram recording and reproducing apparatus, hologram recording and reproducing method, and spatial light modulator for the same
WO2007049383A1 (en) * 2005-10-25 2007-05-03 Fujitsu Limited Hologram recording device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0934540B1 (en) * 1996-10-28 2004-12-22 Pacific Holographics, Inc Apparatus and method for generating diffractive element using liquid crystal display
KR100227179B1 (en) 1997-04-11 1999-10-15 박호군 The manufacture apparatus for reflection type holographic optic element of high quality
US6281993B1 (en) * 1998-03-30 2001-08-28 International Business Machines Corporation Phase shifting element for optical information processing storing systems
JP2006099880A (en) * 2004-09-29 2006-04-13 Toshiba Corp Hologram recording and reproducing apparatus, hologram recording and reproducing method, and spatial light modulator for the same
WO2007049383A1 (en) * 2005-10-25 2007-05-03 Fujitsu Limited Hologram recording device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101883235B1 (en) * 2017-06-05 2018-07-30 주식회사 미래기술연구소 Injection molding method of an outer panel having a hologram for a tail lamp of a car
KR20200048921A (en) * 2018-10-31 2020-05-08 주식회사 미래기술연구소 Manufacturing method of security hologram sticker labels

Also Published As

Publication number Publication date
KR101669825B1 (en) 2016-10-27

Similar Documents

Publication Publication Date Title
US20220137404A1 (en) Methods and systems for generating virtual content display with a virtual or augmented reality apparatus
US8783878B2 (en) Optical system and method
US8690341B2 (en) Image projector and an illuminating unit suitable for use in an image projector
US20060291031A1 (en) Arrangement of aperture diaphragms and/or filters, with changeable characteristics for optical devices
US10739607B2 (en) Light source module, sensing device and method for generating superposition structured patterns
KR101669825B1 (en) Manufacturing method of holographic optical elements using spatial light modulator
JP2013522667A (en) Diffraction type combiner for head-up color display
KR20150072151A (en) Hologram printing apparatus and method for recording of holographic elements images using spatial light modulator
US10838359B2 (en) Hologram reproducing apparatus and method thereof
KR100993625B1 (en) Laser direct imaging system having multi scanner unit
JP2010199605A (en) Illumination optical system
JP2018112755A (en) Illumination optical device, illumination method, exposure device, exposure method, and method of producing device
CN113631984A (en) Projector with laser and phosphor
JP2008152019A (en) Light source device, image display apparatus, projector, illumination apparatus and monitor apparatus
KR20020084155A (en) Illumination optical system and projector using the same
KR20180024741A (en) Manufacturing method of glass master having arbitrary hologram and security mark using spatial light modulator
KR102612558B1 (en) Hologram printing apparatus for recording of holographic elements images tiling multiple spatial light modulator
KR100832620B1 (en) Display system using one panel optical modulator
JP2013195801A (en) Holographic stereogram recording device and method
JP2013195802A (en) Holographic stereogram recording device and method
JP3673959B2 (en) Method for producing hologram
KR20100045267A (en) Laser projection display system provided with a diffractive optical element for decreasing speckle
RU2207611C2 (en) Facility generating iridescent holograms
CN115542702A (en) Diffraction field printing system and optical output method
KR20220075862A (en) Hologram printing system based on microlens array

Legal Events

Date Code Title Description
A201 Request for examination
N231 Notification of change of applicant
N231 Notification of change of applicant
E902 Notification of reason for refusal
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
FPAY Annual fee payment

Payment date: 20190813

Year of fee payment: 4