KR100590519B1 - manufacturing method of a diffuser for making the holographic optical element for 3 dimensional display device and manufacturing method of holographic optical element adopting the same - Google Patents

Abstract

A method of manufacturing a diffuser for manufacturing a hologram device of a 3D display device and a method of manufacturing a hologram device using the same are disclosed. The disclosed method of manufacturing a diffuser includes: irradiating a first reference light in a direction inclined at a predetermined angle with respect to a transparent first photographic plate on which a first photosensitive film is formed, and simultaneously radiating diffused light on the photosensitive film of the first photographic plate to the photosensitive film. Forming a latent image by diffraction and interference of the diffused light and the first reference light; Developing a first photosensitive film of the first photographic plate having a latent image formed thereon; A second reference light is incident on the diffuser processing second photographic plate on which the second photosensitive film is formed, and the first pair of reference light is incident on the first photographic plate at a predetermined angle, and then transmitted through the first photographic plate. Injecting light into the photosensitive film of the second photographic plate to form a latent image by diffraction and interference of the second reference light and the first pair of reference light beams; And developing a second photosensitive film of the second photographic plate to produce a holographic diffuser having a diffraction grating having a predetermined pattern.

The present invention as described above applies a holographic diffuser as a diffuser and utilizes the light convergence function of the holographic element. Such a holographic diffuser is able to produce a good quality HOE because the light is incident on the entire HOE, which is the final production target.

HOE, 3D, display

Description

Manufacture method of a diffuser for making hologram device of the three-dimensional display device and a method for manufacturing the hologram device applying the same The holographic optical element for 3 dimensional display device and manufacturing method of holographic optical element adopting the same}

1 is a schematic configuration diagram of a general three-dimensional display device.

2 is a diagram illustrating HOE production by a conventional method.

3 is a view for explaining the first step of the manufacturing method of the holographic diffuser according to the present invention.

4 is a view for explaining a second step of the manufacturing method of the holographic diffuser according to the present invention.

5 is a view for explaining the convergence state of light by the holographic diffuser manufactured by the present invention.

6 and 7 illustrate a manufacturing process of the hologram device of the 3D display device according to the present invention.

The present invention relates to a method for manufacturing a hologram device diffuser of a three-dimensional display device and a method for manufacturing a hologram device using the same, in particular, to manufacture a diffuser for manufacturing a hologram device of a three-dimensional display device that can reduce the partial luminance difference of the hologram device It relates to a method and a method of manufacturing a hologram device applying the same.

A three-dimensional display device using an LCD (Liquid Crystal Display) is to separate the incident left and right images displayed by the LCD into the left and right eyes to feel the three-dimensional image.

Referring to FIG. 1, a holographic optical element (HOE) is provided at the rear of the LCD display 2, and a conjugated reference beam is incident at a predetermined angle from the rear of the HOE 1. In the LCD, left and right images are displayed in units of even columns and radix columns by an interlacing method. According to this structure, the virtual real stereoscopic image 4 is displayed in front of the LCD (2).

The HOE has a stripe type diffraction grating and is manufactured by a two-split exposure method as shown in FIG.

A mask 5 having a stripe of a pitch corresponding to the pixel pitch of the LCD element is placed in front of a photoplate 1a coated with a silver salt lamp such as a photographic plate. Then, a light diffusing plate 6 such as a liver glass or the like is positioned at a predetermined distance from the mask 5, and light covering 1/2 of the light diffusing plate 6 is disposed on the light diffusing plate 6. Position the stop 7.

In this state, an object beam is irradiated from an upper portion of the light diffusion plate 6, and a reference beam is incident from a side of the mask 5 in a predetermined angle inclined direction.

When the photosensitive film on the photo plate 1a is exposed as described above, a latent image for one side image due to diffraction and interference of the object beam and the reference beam is formed on the photosensitive film.

Subsequently, the photosensitive film is exposed to light in the above state while changing the position of the stop 7 and moving the mask 5 by the reference pitch.

As described above, when the exposure for the left and right images is completed, a HOE element is obtained through a development process or the like. The above exposure method divides the diffuser plate into two and injects light into the divided 1/2 area, and firstly exposes the photoresist film by the light incident through the mask below the light. Is incident, but the lower mask is subjected to the second exposure while the first pitch of the pixel is moved.

The problem with the conventional method for manufacturing a HOE device as described above is that the diffusion of light by the diffusion plate does not occur evenly over the entire surface of the photo plate 1a. For example, as illustrated in FIG. 2, when the object beam 8 is diffused by the half of the diffuser plate 6, the object beam 8 is diffused to the outer portion A of the portion covered by the stop 7. The object beam is also weaker in intensity than other portions, that is, portions B corresponding to the lower portions of the light transmitting region of the diffusion plate 6. This phenomenon also occurs even when the exposure is performed by changing the position of the stop 7.

As a result, in the HOE device, the middle part transmits light with an even distribution, but in the peripheral region, the light emission amount is smaller than the middle part due to the lack of light exposure. This difference in transmission amount results in the luminance of the peripheral area appearing lower than that of the intermediate area in the stereoscopic image. That is, according to the conventional method, the left and right video windows are configured by recording a diffuser such as gantry as an object on a photographic plate. To produce a large 3D display, a large HOE must be manufactured. The angle is limited so that light cannot be diffused to the front of the photographic plate. When the recorded HOE is reproduced, the central and peripheral images of the LCD, which are combined with the left and right images, do not come into the eye at the same intensity.

It is a first object of the present invention to provide a method for manufacturing a HOE device having an even light transmittance as a whole.

A second object of the present invention is to provide a method for manufacturing a diffuser capable of manufacturing a HOE device having an even light transmittance as a whole.

It is a third object of the present invention to provide a method of manufacturing a diffuser for manufacturing a holographic optical device of a 3D display device capable of significantly reducing a local luminance difference of a stereoscopic image, and a method of manufacturing a HOE using the same.

In order to achieve the above object, a method of manufacturing a holographic diffuser for manufacturing a HOE of a three-dimensional display device according to the present invention is:

Irradiating the first reference light in a direction inclined at a predetermined angle with respect to the transparent first photographic plate on which the first photosensitive film is formed, and simultaneously radiating diffused light to the photosensitive film of the first photographic plate so that the diffused light and the first reference Forming a latent image by diffraction and interference of light;

Developing a first photosensitive film of the first photographic plate having a latent image formed thereon;

A second reference light is incident on the diffuser processing second photographic plate on which the second photosensitive film is formed, and the first pair of reference light is incident on the first photographic plate at a predetermined angle, and then transmitted through the first photographic plate. Injecting light into the photosensitive film of the second photographic plate to form a latent image by diffraction and interference of the second reference light and the first pair of reference light beams;

And developing a second photosensitive film of the second photographic plate to produce a holographic diffuser having a diffraction grating having a predetermined pattern.

In addition, the manufacturing method of the HOE of the three-dimensional display device according to the present invention to achieve the above object:

Irradiating the first reference light in a direction inclined at a predetermined angle to the transparent first photographic plate on which the first photosensitive film is formed, and simultaneously radiating diffused light to the photosensitive film of the first photographic plate so that the diffused light and the first reference light Forming a latent image by diffraction and interference;

Developing a first photoresist film of the photographic plate on which a latent image is formed;

The light transmitted through the first photographic plate after injecting a second reference light in a predetermined angle direction to the second photographic plate for forming the second photosensitive film on which the second photosensitive film is formed and incident the first pair of reference light at a predetermined angle. Incident light on the photosensitive film of the second photographic plate to form a latent image due to diffraction and interference of the second reference light and the conjugate reference light;

Developing a second photosensitive film of the second photographic plate to form a holographic diffuser having a predetermined pattern with a diffraction grating;

Positioning the holographic diffuser in front of a third photo plate for HOE processing on which a third photoresist film is formed, and positioning an exposure mask adjacent to the second photo plate between the third photo plate and the holographic diffuser;

A second pair of reference light is incident on the first area of the two divided areas of the holographic diffuser in a direction inclined at a predetermined angle, and a third reference light is incident on the mask in a direction inclined at a predetermined angle with respect to a surface. Performing an exposure;

Performing second exposure to a portion of the third photosensitive film that is not exposed by the first exposure by the second pair of reference light and the third reference light while the mask is shifted by one pitch;

And developing a third photosensitive film of the third photographic plate to obtain a desired HOE.

In the exposing step of the first photographic plate of the manufacturing method of the present invention, the first reference light is parallelized light, and the diffused light is provided in the diffusion plate having a larger area than the first photographic plate. It is characterized by generating by.

Hereinafter, a method of manufacturing a diffuser for manufacturing a holographic optical device according to the present invention and a method of manufacturing a HOE using the same will be described in detail with reference to the accompanying drawings.

<< How to Make a Holographic Diffuser >>

As shown in FIG. 3, the photosensitive film formed on the first photographic plate 11 is exposed using a master diffuser 10 such as glass. At this time, in order to record a uniform diffuser image on the first photographic plate 11, a master diffuser 10 such as glass glass having a larger size than that of the first photographic plate 11 is applied. At this time, in order to maintain a constant size of the object to be replayed later, the first reference light 14 parallelized by the collimating lens 13 is incident on one side of the first photographic plate 11, and the first reference light ( 14) and the interference H1 due to diffraction and interference of the diffused light are formed (exposure) on the photosensitive film of the first photographic plate 11. Then, the photosensitive film exposed as described above is developed. In the drawings, reference numeral 12 denotes a light source.

As shown in FIG. 4, the hologram image H1 recorded on the first photographic plate 11 illuminates the first pair of reference beams 15 and the image H1 of the original diffuser 10. ') Appears in space. Using this image as an object, exposure to the second photographic plate 17 is carried out using a second reference light 16 which is further parallelized. That is, as shown in FIG. 4, the first photo plate 11 is applied as a diffusion plate to expose the second photo plate 17 on which the second photosensitive film is formed. At this time, the second reference light 16 is incident in a direction inclined at a predetermined angle with respect to the second photographic plate 17, and thus, the pattern H2 due to diffraction and interference is recorded in the photosensitive film of the second photographic plate 17. .

As shown in Fig. 5, when the second condensation reference light 18 is illuminated on the second photographic plate 17 on which the H2 pattern is recorded, the H1 real image is displayed in space. In general, since the hologram has a high information density, the entire object is reproduced as it is even if the hologram is hidden. By applying this, the above-described H2 is reflected back to the pair of reference beams so that the actual image of H1 reproduced is visible even if it covers half of the second photographic plate 17. When H2 is regenerated in this state, the second pair of reference light 18 is diffracted and the light converges to the H1 image. At this time, the HOE of the present invention can be obtained by setting up H2 to act as a light diffuser in the two-split exposure method as shown in FIG.

<< HOE production method >>

The second photographic plate 17 finally obtained through the above process is applied as a light diffuser for producing a HOE. Hereinafter, the second photographic plate 17 is called a holographic diffuser.

As shown in FIG. 6, the mask 20 is positioned on the third photo plate 21 to be processed into the HOE, and the holographic diffuser 17 finally obtained in the above-described process is disposed above the mask 19. Locate it.

The second pair of reference light 18 is irradiated to the holographic diffuser 17 while the half of the holographic diffuser 17 is covered by the stop 19 for the first exposure. For example, the third reference light 22 is irradiated in a constant angle direction, and a pattern by diffraction and interference between the second pair of reference light 18 and the third reference light 22 is recorded on the third photographic plate 21.

For the second exposure, the method as described above in the state where the position of the stop 19 is changed as shown in FIG. (21) is exposed.

As described above, when the first and second exposures are completed, the photosensitive film of the third photographic plate 21 is developed to obtain a desired HOE.

The present invention as described above applies a holographic diffuser as a diffuser and utilizes the light convergence function of the holographic element. Such a holographic diffuser is able to produce a good quality HOE because the light is incident on the entire HOE, which is the final production target.

That is, the present invention can be manufactured so that the low diffraction occurs with uniform intensity in the entire area of the final large HOE by replacing the conventional diffuser with the holographic diffuser using the general hologram principle repeatedly. In addition, in the conventional method, two object beams are required, but according to the present invention, only parallelized beams are required, thereby simplifying setup for manufacturing the HOE.

Claims (6)

Irradiating the first reference light in a direction inclined at a predetermined angle with respect to the transparent first photographic plate on which the first photosensitive film is formed, and simultaneously radiating diffused light to the photosensitive film of the first photographic plate so that the diffused light and the first reference are applied to the photosensitive film. Forming a latent image by diffraction and interference of light; Developing a first photosensitive film of the first photographic plate having a latent image formed thereon; A second reference light is incident on the diffuser processing second photographic plate on which the second photosensitive film is formed, and the first pair of reference light is incident on the first photographic plate at a predetermined angle, and then transmitted through the first photographic plate. Injecting light into the photosensitive film of the second photographic plate to form a latent image by diffraction and interference of the second reference light and the first pair of reference light beams; And developing a second photosensitive film of the second photographic plate to manufacture a holographic diffuser having a diffraction grating. The method of claim 1, In the exposing step for the first photographic plate, The first reference light is parallelized light manufacturing method of manufacturing a diffuser for HOE of the three-dimensional display device. The method according to claim 1 or 2, The diffused light is generated by the diffuser plate having a larger area than the first photo plate, the manufacturing method of the HOE diffuser for a three-dimensional display device. Irradiating the first reference light in a direction inclined at a predetermined angle to the transparent first photographic plate on which the first photosensitive film is formed, and simultaneously radiating diffused light to the photosensitive film of the first photographic plate so that the diffused light and the first reference light Forming a latent image by diffraction and interference; Developing a first photoresist film of the photographic plate on which a latent image is formed; The second reference light is incident on the diffuser processing second photographic plate on which the second photosensitive film is formed, and the first pair of reference light is incident on the first photographic plate at a predetermined angle. Incident to the photosensitive film of the second photographic plate to form a latent image due to diffraction and interference of the second reference light and the conjugate reference light; Developing a second photosensitive film of the second photographic plate to form a holographic diffuser having a diffraction grating; Positioning the holographic diffuser in front of a third photo plate for HOE processing on which a third photoresist film is formed, and positioning an exposure mask adjacent to the second photo plate between the third photo plate and the holographic diffuser; The second pair of reference light is incident on the first area of the two divided areas of the holographic diffuser in a direction inclined at a predetermined angle, and the third reference light is incident on the mask in a direction inclined at a predetermined angle with respect to a surface. First exposing the photosensitive film; In the state where the mask is shifted by one pitch, a second pair of reference light is incident on the second divided area of the holographic diffuser in a direction inclined at a predetermined angle, and the angle is inclined with respect to the surface in the mask. Injecting a third reference light into the second photoresist to expose the third photoresist; Developing the third photoresist film of the third photo plate to obtain a desired HOE; HOE manufacturing method of a three-dimensional display device comprising a. The method of claim 4, wherein In the exposing step for the first photographic plate, The first reference light is parallelized light manufacturing method of manufacturing a diffuser for HOE of the three-dimensional display device. The method according to claim 4 or 5, The diffused light is generated by the diffuser plate having a larger area than the first photo plate, the manufacturing method of the HOE diffuser for a three-dimensional display device.

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