KR20240038850A - Replicating apparatus and method of large-area holographic optical element - Google Patents

Abstract

The present invention relates to an apparatus and method for replicating a large-area holographic optical element using a photopolymer. The method for replicating a large-area holographic optical element of this embodiment includes irradiating reference light to the master and disposing the master between the light source and the master. A process of replicating a hologram on a panel, including (a) preparing black glass with a light absorption layer, (b) attaching a plurality of divided masters to the surface of the black glass so that they are adjacent to each other to form a large-area tiling master. Steps (c) laminating a replication panel on the top surface of the tiling master, and (d) replicating a hologram on the replication panel by irradiating reference light while scanning the top surface of the tiling master in a certain area.

Description

Replicating apparatus and method of large-area holographic optical element}

The present invention relates to holographic optical devices, and more specifically, to a device and method for replicating large-area holographic optical devices using photopolymer.

Holographic optical elements (HOE) are devices in which a specific grid pattern is formed by reference light and object light, and are necessary for recording and reproducing holograms.

Recently, much attention has been focused on the implementation of holographic optical devices with optical functions. HOE has high diffraction efficiency, narrow-band frequency characteristics, and can implement various optical functions with a single device, so it is used to display information in airplanes and automobiles. It is widely used in HUD (head-up display), HMD (head mounted display) for augmented reality, and 2D/3D display screens. HOE technology is expected to be applied to a wider range of applications in the future.

In order to respond to such diverse application fields and cases, hologram production and replication technology is essential because mass production and distribution of HOE will be necessary in the future. Hologram replication means transferring the interference information stored in the original hologram, that is, the master hologram, to the copy object (replication film).

Hologram replication technology can be divided into mechanical and optical methods depending on the characteristics of the replication technology, and the present invention proposes optical replication technology. Optical replication technology refers to a technology in which a hologram is copied by irradiating coherent light (usually a laser beam) to the radiator (master hologram film) and the radiator (photosensitive medium such as photopolymer film).

Recently, as automotive HUD and augmented reality (AR) display devices have developed and their uses have become more diverse, the need for replicating large-screen holographic optical elements is increasing. To this end, Korean Patent Publication No. 10-2022-0026521 introduces a method of replicating large-area holographic optical devices using a nanoimprinting process.

The method of replicating an optical element in the prior patent document involves manufacturing a master with a diffraction grid pattern element through a nanoimprinting process, placing a photocurable panel on the top, and then simultaneously moving the light source and the master while the reference light is incident. Alternatively, this is a method of repeatedly replicating while moving only the photocurable panel.

As in the prior patent literature, in the method of replicating a large-area holographic optical device using a nanoimprinting master, an air gap is generated due to the pattern between the master and the photocurable panel during replication, which reduces the coherence of the laser light source. Diffraction efficiency and replication performance are significantly reduced.

In addition, as in the prior patent literature, when replicating a nanoimprinting master, the master is transparent, so the transmitted reference light passes through the master and is then reflected on an object such as a jig on the back, thereby replicating a material other than the master to be copied, thereby determining the replication rate for the master information. This decreases significantly.

In other words, in the method of replicating large-area holographic optical elements using a conventional nanoimprinting master, the imprint is degraded due to the air gap, and the deviation in the imprint rate due to rear reflection of transmitted light is large, leading to a sharp deterioration in image quality, especially in white implementations. There is.

Korean Patent Publication No. 10-2022-0026521

The present invention was proposed to solve the above problems, and its object is to provide a large-area holographic optical element replication device and method that can improve the replication rate and image quality by solving the problems of air gap occurrence and re-reflection of transmitted light. Do this.

The large-area holographic optical element replica device of the present embodiment for solving the above problems includes a jig part provided with black glass having a light absorption layer, a light source part disposed on an upper part of the jig part and irradiating reference light of a certain area size, and a scanning driver that controls a predetermined area to which the reference light is irradiated to be scanned, and is configured to scan and replicate a large-area master area combined with the black glass in divided areas of a predetermined size.

Additionally, the scanning driver may include at least one of a jig movement unit that controls movement of the jig unit or a light source movement unit that controls movement of the light source unit.

In addition, the scanning driving unit may be configured to control the driving of either the jig moving unit or the light source moving unit or to control the driving of both simultaneously.

In addition, the black glass may be composed of glass containing a light-absorbing material inside, transparent glass coated with a light-absorbing material on the surface, or transparent glass with a light-absorbing film attached to the surface.

In order to solve the above problems, the replication method of the large-area holographic optical element of this embodiment is a process of radiating reference light to the master and replicating the hologram on a panel disposed between the light source and the master, comprising: (a) a light absorption layer; Preparing black glass having, (b) attaching a plurality of split masters to the surface of the black glass so that they are adjacent to each other to form a large-area tiling master, (c) laminating a replica panel on the top surface of the tiling master. and, (d) replicating the hologram on the replication panel by irradiating reference light while scanning the upper surface of the tiling master in units of certain areas.

Additionally, the replica panel may be composed of a photopolymer panel having the same area as the tiling master.

Additionally, in step (b), a tiling master may be formed by attaching a plurality of the divided masters through a light-transmitting adhesive member.

Additionally, the plurality of divided masters may be composed of photopolymer panels having the same size.

Additionally, in step (b), a tiling master may be manufactured by attaching a plurality of the divided masters to the light-transmitting adhesive member so that they are adjacent to each other, and then the tiling master may be laminated to the black glass.

Additionally, in step (b), after attaching the translucent adhesive member to the black glass, a tiling master may be formed by attaching a plurality of the divided masters to the translucent adhesive member so that they are adjacent to each other.

Additionally, in step (d), reference light may be irradiated while scanning in the divided master units.

According to this embodiment, by replicating the large-area hologram record, it is possible to easily implement a large-screen HUD or transparent display device for AR.

In addition, according to this embodiment, when replicating a large-area holographic record, the problem of air gap occurrence and re-reflection of transmitted light is solved, thereby improving problems of low replication efficiency and poor image quality, and has the effect of increasing color gamut. .

1 is a side view showing a large-area holographic optical device replication structure according to this embodiment;
Figure 2 is a perspective view showing a large-area holographic optical device replication structure according to this embodiment;
3 is a plan view showing a tiling master according to this embodiment;
Figure 4 is a block diagram showing the main configuration of the holographic optical element replicating device according to this embodiment;
Figure 5 is a flowchart showing the large-area holographic optical device replication process according to this embodiment;
FIG. 6 is a diagram comparing the results of replicating a conventional large-area holographic optical device with the results of replicating a large-area holographic optical device of the present embodiment.

The technical problems achieved by the present invention and its implementation will become clear by the preferred embodiments described below. Hereinafter, preferred embodiments of the present invention will be examined in detail with reference to the attached drawings.

It should be understood that the differences in this embodiment, described later, are not mutually exclusive. That is, without departing from the spirit and scope of the present invention, the specific shape, structure, and characteristics described may be implemented in other embodiments with respect to one embodiment, and the positions of individual components within each disclosed embodiment. Alternatively, it should be understood that the arrangement may be changed, and similar reference numbers in the drawings refer to the same or similar functions across various aspects, and the length, area, thickness, etc. may be exaggerated for convenience. In the description of this embodiment, expressions such as up, down, left, right, etc. indicate relative positions or directions, and their technical meaning is not limited by dictionary meaning.

Figure 1 is a side view showing a large-area holographic optical element replication structure according to this embodiment, Figure 2 is a perspective view showing a large-area holographic optical element replication structure according to this embodiment, and Figure 3 is a large-area holographic optical element replication structure according to this embodiment. This is a floor plan showing the tiling master.

The holographic optical element replication of this embodiment is configured so that a replication panel is interposed between the light source and the master, and replication is performed using reflected light reflected from the master when reference light is irradiated from the light source.

As shown in Figures 1 and 2, the holographic optical element replication structure for this places a tiling master (20) on top of black glass (10), and a replication panel (30) on top of it. After lamination, a structure is formed in which laser light is irradiated from the top. For this purpose, a light source that irradiates laser light is placed at the top.

Specifically, the black glass 10 can form a jig device as a structure that supports the tiling master 20 and the replication panel 30 for hologram replication. In particular, the black glass 10 of this embodiment is characterized by having a light absorption layer 11. For example, the black glass 10 is composed of glass containing a light absorption material therein, or has a transparent glass surface with a light absorption layer 11. It may be formed by coating an absorbent material, or it may be formed by attaching a light-absorbing film to the surface of transparent glass.

The black glass 10 having the light absorption layer 11 absorbs the transmitted light L3 passing through the tiling master 20 and prevents the transmitted light L3 from being reflected by the support structure. The reference light L1 emitted from the light source on the upper side is divided into reflected light L2, which is reflected in the process of passing through the tiling master 20, and transmitted light L3, which is transmitted. At this time, the transmitted light L3 is reflected by the black glass 10, which is a support structure, and passes through the tiling master 20 on the upper side again.

In this way, the light reflected from the black glass 10 interferes with the reflected light L2 for replication or is copied to the replication panel 30, thereby lowering the color gamut or image quality of the hologram that must be copied to the actual replication panel 30. It may cause defects. However, since the black glass 10 of this embodiment is provided with the light absorption layer 11, it absorbs the transmitted light L3 passing through the tiling master 20, thereby preventing problems caused by reflection of the transmitted light L3. .

The tiling master 20 is a panel on which hologram information to be copied is recorded, and forms a tile structure in which a plurality of split masters 21 are arranged adjacent to each other in the horizontal and/or vertical directions (or left and right directions). The division master 21 is composed of a photopolymer panel, and the same or different hologram information may be recorded on each division master 21.

In addition, each divided master 21 is formed to have the same size, and a plurality of divided masters 21 are attached adjacent to each other via a translucent adhesive member 22 (OCA) to form a tiling master 20 of a predetermined area. You can. For example, as shown in FIG. 3, the tiling master 20 may be composed of eight split masters having a 2 x 4 array structure.

The tiling master 20 of this embodiment is composed of a plurality of divided masters 21, so that a large-area master can be implemented. At this time, each division master 21 may have a size of 20" or less.

The replication panel 30 is a configuration in which the holographic information of the tiling master 20 is copied, and the information is copied according to the diffraction pattern of the reflected light L2 reflected from the tiling master 20. The replication panel 30 for this purpose is composed of a photopolymer panel that reacts to light, and is composed of a photopolymer panel with an area equal to the total area of the tiling master 20. Accordingly, in the replication panel 30, the hologram information of the corresponding division master 21 is copied in the virtual division area corresponding to each division master 21, and finally, the entire hologram information of the tiling master 20 is copied.

Meanwhile, the replica panel 30 is arranged to be bonded to the upper surface of the tiling master 20, and in particular, the bonding is performed through a laminating process to prevent air bubbles from being generated between the replica panel 30 and the tiling master 20. As such, an air gap is not created between the replication panel 30 and the tiling master 20, so the reference light L1 passes through the replication panel 30 or the reflected light L2 is reflected from the tiling master 20. In the process, deterioration of diffraction efficiency and replication performance due to the air gap is prevented.

Figure 4 is a block diagram showing the main configuration of the holographic optical element replicating device according to this embodiment.

Referring to the drawings, the holographic optical element replicating device of the present embodiment includes a jig portion 100 provided with black glass, a light source portion 200 disposed on top while being spaced apart from the jig portion 100 by a predetermined distance, and a light source portion 200. ) may include a scanning driver 300 that controls the reference light emitted from the surface of the tiling master 20 to be sequentially emitted.

The jig unit 100 is configured to mount and secure a photopolymer module (HOE) for hologram replication. The photopolymer module (HOE) is a combination of a tiling master (20) and a replication panel (30). In particular, the jig part 100 includes black glass 10 as a base substrate to which a photopolymer module (HOE) is attached. Black glass 10 has a light absorption layer 11 for absorbing transmitted light.

The light source unit 200 is configured to radiate reference light to the tiling master 20. The light source unit 200 radiates reference light while scanning the large-area tiling master 20 in units of a certain area. Additionally, the light source unit 200 irradiates a laser beam with an energy of at least 20 mJ/cm2 as a reference light.

The scanning driver 300 controls the reference light from the light source 200 to be sequentially scanned and irradiated along the surface of the tiling master 20.

The light source unit 200 cannot radiate reference light to the entire surface of the large-area tiling master 20 at the same time, so it radiates reference light in units of a certain area. The light source unit 200 may irradiate reference light in units of the division masters 21 of the tiling master 20, and at this time, the scanning driver 300 may irradiate the reference light sequentially to the neighboring division masters 21. 100) or the movement of the light source unit 200 is controlled.

For example, with respect to the tiling master 20 having a 2 x 4 array structure as shown in FIG. 3, the light source unit 200 first radiates reference light to the first division master 21-1 on the upper left and then radiates the reference light in the right direction (x direction). ), the neighboring divided masters are irradiated, and when the fourth divided master (21-4) is irradiated, the fifth divided master (21-5) is irradiated while scanning in the downward direction (-y direction). Then, while scanning again in the left direction (-x direction), the reference light is irradiated up to the last eighth divided master (21-8).

In this way, the scanning driver 300 drives the light source 200 to sequentially irradiate reference light in units of predetermined areas.

The scanning driver 300 for this purpose is at least one of a light source moving unit 310 that moves the position of the light source unit 200 or a jig moving unit 320 that moves the position of the jig part 100, that is, the tiling master 20. may include.

Therefore, the scanning driver 300 controls the light source moving unit 310 to scan the tiling master 20 while the light source 200 moves while the jig part 100 is fixed, and the jig moving unit ( By controlling 320, scanning of the tiling master 20 can be performed while the jig unit 100 moves while the light source unit 200 is fixed.

In addition, the scanning driver 300 simultaneously controls the light source movement unit 310 and the jig movement unit 320 so that the light source unit 200 and the jig unit 100 move together while scanning the tiling master 20. can do. If scanning is performed while moving the light source unit 200 and the jig unit 100 together, the duplication time can be shortened.

Figure 5 is a flowchart showing the large-area holographic optical device replication process according to this embodiment.

Referring to the drawings, in the process of replicating a holographic optical element according to this embodiment, first, the black glass 10 to which the tiling master 20 will be attached is prepared (S11). The black glass 10 includes a light absorption layer 11, and the prepared black glass 10 can be mounted on the jig unit 100.

Then, a tiling master 20 is manufactured by connecting a plurality of divided masters 21 to each other in a predetermined arrangement structure in the horizontal and vertical directions (S12). The plurality of split masters 21 can be connected to each other in a tiling structure by bonding to one surface of the light-transmitting adhesive member 22. Afterwards, the tiling master 20 is attached to the surface of the black glass 10 (S13). The tiling master 20 can attach the translucent adhesive member 22 to the surface of the black glass 10 and laminate it.

Meanwhile, in this embodiment, the process of manufacturing the tiling master 20 by attaching a plurality of split masters 21 to the translucent adhesive member 22 and then laminating it to the black glass 10 is exemplified, but this is, After attaching the translucent adhesive member 22 to the surface of the black glass 10, a plurality of split masters 21 are tiled on the translucent adhesive member 22 to form the tiling master 20 directly on the black glass 10. It also means

Then, the replication panel 30 is laminated on the upper surface of the tiling master 20 and joined to prevent bubbles from occurring (S14), and hologram replication is started by irradiating reference light to the area of the first division master 21-1 (S15). , the entire area of the large-area tiling master 20 is copied by scanning operation (S16).

FIG. 6 is a photographic diagram comparing the results of replicating a conventional large-area holographic optical device with the results of replicating a large-area holographic optical device of this embodiment.

Looking at Figure 6 (a), looking at the conventional reproduction result, it can be seen that light scattering by the air gap and transmitted light re-reflected from the structure record the reflected light of objects other than the engraving, resulting in a significant deterioration in the image quality of the white implementation. You can. On the other hand, looking at (b) of FIG. 6, it can be seen that the reproduction result of this example shows that this poor image quality is greatly improved and the color gamut is also greatly improved.

According to the holographic optical device replication process of this embodiment, interference by reflected light can be prevented by using black glass with a light absorption layer as a base substrate. Additionally, according to the holographic optical device replication process of this embodiment, an air gap is not formed between the master and the replication panel, thereby preventing degradation of replication performance due to the air gap.

Although exemplary embodiments of the present invention have been shown and described as described above, various modifications and other embodiments will occur to those skilled in the art. These modifications and other embodiments are to be considered and included in the appended claims without departing from the true spirit and scope of the present invention.

10: Black glass 11: Light absorption layer
20: Tiling Master 21: Splitting Master
22: Transparent adhesive member
30: Replication panel
100: Jig part
200: Light source unit
300: scanning driving unit

Claims (11)

A jig portion provided with black glass having a light absorption layer;
a light source unit disposed on an upper portion of the jig unit to irradiate reference light of a certain area size; and
Including a scanning driver that controls a certain area to which the reference light is irradiated to be scanned,
A cloning device for a large-area holographic optical element that scans and replicates a large-area master area combined with the black glass in divided areas of a certain size. According to claim 1,
The scanning drive unit includes at least one of a jig movement unit that controls movement of the jig unit or a light source movement unit that controls movement of the light source unit. According to claim 2,
The scanning driving unit is configured to control the driving of either the jig moving unit or the light source moving unit or to simultaneously control the driving of the large-area holographic optical element. According to claim 1,
The black glass is a replica device of a large-area holographic optical element, which consists of glass containing a light-absorbing material inside, transparent glass coated with a light-absorbing material on the surface, or transparent glass with a light-absorbing film attached to the surface. This is the process of radiating reference light to the master and replicating the hologram on a panel placed between the light source and the master.
(a) preparing black glass having a light absorption layer;
(b) forming a large-area tiling master by attaching a plurality of divided masters to the surface of the black glass so that they are adjacent to each other;
(c) laminating a replica panel on the top surface of the tiling master; and,
(d) replicating the hologram on the replica panel by irradiating reference light while scanning the tiling master's upper surface in units of certain areas. According to claim 5,
A method of replicating a large-area holographic optical device, wherein the replica panel is composed of a photopolymer panel having the same area as the tiling master. The method of claim 5, wherein step (b) is,
A method of replicating a large-area holographic optical element, forming a tiling master by attaching a plurality of the divided masters using a light-transmitting adhesive member. According to claim 7,
A method of replicating a large-area holographic optical device, wherein the plurality of divided masters are composed of photopolymer panels having the same size. The method of claim 7, wherein step (b) is:
A method of replicating a large-area holographic optical element, manufacturing a tiling master by attaching a plurality of the divided masters to the light-transmitting adhesive member so that they are adjacent to each other, and then laminating the tiling master to the black glass. The method of claim 7, wherein step (b) is:
After attaching the translucent adhesive member to the black glass, a plurality of the divided masters are attached to the translucent adhesive member so that they are adjacent to each other to form a tiling master. The method of claim 5, wherein step (d) is:
A method of replicating a large-area holographic optical element, irradiating reference light while scanning in the divided master unit.

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