KR20150121545A - Reflection-type three-dimensional screen - Google Patents

Abstract

The present invention relates to a screen used in a projection type three-dimensional image display system for projecting a three-dimensional image, which transmits an output three-dimensional image and includes a single lens array composed of a plurality of lenses and a recursive And a reflective film.

Description

Reflection-type three-dimensional screen [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflective type three-dimensional screen used in a projection type three-dimensional image display system, and more particularly, Dimensional reflection screen.

A projection-type diplay, also referred to as a projector, includes a spatial light modulator (SLM) for modulating a source image, a spatial light modulator (SLM) for modulating the size of the modulated image in the spatial light modulator And a plurality of projection lenses. Such a projection type image display apparatus can be classified into a liquid crystal display (LCD) type, a digital mirror device type (DMD), a liquid crystal display type (LCOS) silicon). In particular, the projection type image display apparatus has an advantage that the focal distance of the projection lens can be simply adjusted, and is used for theater, office, and camping.

In particular, the projection-type image display apparatus is used in a projection-type three-dimensional display system for displaying a three-dimensional image. That is, a projection-type three-dimensional display system is a system for generating a three-dimensional image on a screen by outputting a three-dimensional source image to a projection lens. However, in such a projection type three-dimensional image display system, there is a problem that the observer can not observe a perfect image due to the limitation of the aperture ratio of the projection lens.

FIG. 1 shows the principle of visibility limitation of a projection type three-dimensional image display system, and schematically shows a configuration of a floating image display system.

As one of the projection type three-dimensional image display systems, there is a three-dimensional floating display system for displaying an image by floating a multi-depth object 10. In this case, the floating lens 12 can be regarded as a projection lens of a three-dimensional image display system. Referring to FIG. 1, in the floating image display system, when the aperture ratio of the floating lens 12 is reduced to a certain level or less 11, the visibility of the floating image 13 is limited accordingly.

The projected image on the projection type image display device is displayed on a screen. A conventional screen has a diffuser on the surface to resolve the visibility limitation of the projection type image display device by scattering the output image in all directions. However, the conventional screen can be applied only to a two-dimensional image having an omnidirectional planar. This is because the surface of the conventional screen scatters the image in all directions, so that the depth or perspective of the volumetric three-dimensional image can not be properly displayed. Therefore, in the projection type three-dimensional image system, a new screen capable of displaying a volumetric three-dimensional image is needed while solving the problem of visibility limitation by the projection lens.

On the other hand, there is a projection type integrated image system as one of the projection type three-dimensional image display systems. The projection type integrated image display system is an integral imaging method in which three-dimensional information of an object is converted into an elemental image using a lens array composed of a plurality of elemental lenses. And displays the basic image through a lens array as a three-dimensional image. In particular, the screen used in the projection type integrated image display system is divided into a transmissive type and a reflective type.

Fig. 2 schematically shows the configuration of a conventional projection type integrated image display system having a transmissive screen.

2, a conventional projection type integrated image display system having a transmissive screen has a structure in which an object 21 photographs an image viewed through a lens array 22 with a photographing element 23 such as a camera, A display unit 20 for outputting the three-dimensional basic image obtained by the pickup unit 20 to the projection 31, passing the basic image through the basic lens 32, and transmitting the three-dimensional basic image to the screen 33 30), and a stereoscopic image (34) is integrated in the back of the screen (33). However, in the conventional projection type integrated image display system having a transmissive screen, if the size of the base lens 32 is more than a certain level, the minimum aperture ratio becomes larger than that of the base lens 32 so that the observer can directly observe the integrated image with the naked eye Can not.

3 shows a transmissive screen of a conventional projection type integrated imaging system.

The conventional transmissive screen 40 is composed of two lens arrays 41 and 42 arranged in parallel and composed of a plurality of lenses as shown in Fig. That is, the conventional transmissive screen 40 receives an integrated image output from the projection type integrated image display system and displays a virtual image and an actual image regardless of the size of the basic lens 32 as a basic image output from the projection 31, The depth of the image was reversed, but the stereoscopic effect could be transmitted.

However, the conventional transmissive screen 40 is difficult to be applied to an actual screen because it is very difficult to arrange the lenses of the lens array in parallel with each other. Further, since the conventional transmissive screen 40 uses a pair of expensive lens arrays 41 and 42, there is a problem that the manufacturing cost is high.

4 and 5 show a reflective screen of a conventional projection type integrated image display system.

On the other hand, the conventional reflective screen 50 has a structure in which a lens array 51 composed of a plurality of lenses and a mirror 52 are arranged side by side as shown in Fig. Referring to FIG. 4, the basic image output from the projection 31 is received by the conventional reflective screen 50 by receiving the integrated image output from the projection type integrated image display system. At this time, the basic image outputted from the projection device 31 is displayed on the conventional reflective screen 50, regardless of the aperture ratio of the projection device, so that the depth of the image is reversed but the stereoscopic effect is transmitted as it is.

5, the conventional reflective screen 50 is configured such that light reflected by the mirror 52 passing through one of the lenses 51a of the lens array 51 passes through the other lens 51b , 51c,..., A part of the light is lost, the image is reversed, and the range of the viewing window for viewing the image is limited.

KR 10-1022565 B1

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional art, and it is an object of the present invention to provide an image display apparatus and an image display method capable of reducing visibility while simultaneously reducing the depth of an image, The present invention also provides a reflective type three-dimensional screen that can be used in various types of projection type three-dimensional image display systems in addition to a projection type integrated image display system.

In order to achieve the above object, a three-dimensional screen according to the present invention is a screen used in a projection-type three-dimensional image system for projecting a three-dimensional image, comprising: (1) A lens array, and (2) a retroreflective film that is disposed side by side so as to be spaced apart from the lens array.

At this time, it is preferable that the distance between the lens array and the retroreflective film is not more than twice the focal length of the lens array, except for the focal length of the lens array.

The three-dimensional screen according to the present invention configured as described above can improve the visibility while simultaneously reducing the depth of the image and providing excellent stereoscopic effect and reducing the light lost even when the aperture ratio of the projection lens is limited. By using only the lens array, the manufacturing cost can be reduced, and in addition to the projection type integrated image display system, it can be used in various projection type three-dimensional image display systems.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a constitution of a floating image display system, showing a principle of restricting visibility of a projection type three-dimensional image display system. Fig.
2 is a view showing a configuration of a conventional projection type integrated image display system having a transmissive screen.
3 is a view showing a transmissive screen of a conventional projection type integrated image display system.
4 and 5 are views showing a reflective screen of a conventional projection type integrated image display system.
6 illustrates a reflective three-dimensional screen in accordance with an embodiment of the present invention.
FIG. 7 is a diagram illustrating that an image is incident and reflected on a reflection type three-dimensional screen according to an embodiment of the present invention; FIG.
8 is a diagram illustrating an experiment for evaluating the feasibility of a reflection type three-dimensional screen according to an embodiment of the present invention.
9 is a photograph showing the result of the experiment according to Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions. Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

6 illustrates a reflective 3D screen in accordance with an embodiment of the present invention.

The reflection type three-dimensional screen according to an embodiment of the present invention is a screen used in a projection type three-dimensional image display system for projecting a three-dimensional image. As shown in FIG. 6, a single lens array 100 and a retroreflective And a film (200).

The lens array 100 is composed of a plurality of lenses 100a, 100b, 100c, ... arranged in a line.

The retroreflective film 200 is a retroreflective film, that is, a reflecting film that sends incident light rays back to the light source as they are, and is disposed so as to be spaced apart from the lens array 100. For example, the retroreflective film 200 may be coated by coating a fine glass bead uniformly on the film, or may have a cubic micro prism formed on the polymer film. Particularly, the most useful one among the retroreflective films is the retroreflective film of the mother lacquer. That is, the retina reflector film includes an array of cornered cubes protruding from the corner. These corner cubes include a three-side structure (i.e., generally three sides that are generally orthogonal to each other and meet at a single corner). Accordingly, the light incident on the retroreflective film of the mother-in-law is reflected by the surface of the corner cube and returns to the direction of the light source.

The three-dimensional reflective screen according to an embodiment of the present invention is characterized in that the lens array 100 is projected on the retroreflective film 200 to display the virtual image of the lens array 100, Is arranged in parallel with the lens array 100 shown in front of the reflective film 200 and has a state such that two lens arrays are arranged.

More specifically, the lens array 100 transmits a three-dimensional image output from a projection lens having a limited aperture ratio, more specifically, a projection lens, to a retroreflective film 200 in a projection type three-dimensional image display system. Then, the retroreflected three-dimensional image in the retroreflective film 200 is transmitted to the observer through the lens array 100 again. At this time, when the three-dimensional image outputted from the projection is transmitted to the retroreflective film 200 through one lens (for example, 100a) of the lens array 100, as shown in Fig. 7, the retroreflective film The three-dimensional image retroreflected by the lens 200 is incident on the corresponding lens 100a without being incident on the other lenses 100b, 100c, ..., and then transmitted to the observer (hereinafter referred to as "retroreflective phenomenon"). Therefore, the reflection type three-dimensional screen according to the embodiment of the present invention does not reverse the image, the loss of light is reduced, and the visibility is improved.

In particular, the interval between the lens array 100 and the retroreflective film 200 affects the reflex reflection phenomenon. That is, when the distance between the lens array 100 and the retroreflective film 200 is at the focal length f of the lens array 100 or exceeds twice the focal length f of the lens array, The reflected three-dimensional image is incident on the other lenses 100b, 100c, ..., and the light is lost. Therefore, the distance between the lens array 100 and the retroreflective film 200 is preferably not more than twice the focal length f of the lens array, excluding the focal distance f of the lens array 100 .

FIG. 8 shows an experiment for evaluating the feasibility of a reflective 3D screen according to an embodiment of the present invention.

That is, in order to compare the performance of the reflective 3D screen and the conventional reflective screen according to an embodiment of the present invention, an apparatus as shown in FIG. 8 is installed. In this case, the conventional reflective screen has a mirror in place of the retroreflective film 200 in a three-dimensional screen according to an embodiment of the present invention. In the experiment shown in FIG. 8, Respectively. This is because, in the case of a conventional reflection type screen, when a lens array is provided, a reflex reflection phenomenon does not occur and light is incident on a plurality of other lenses to observe a plurality of flip images. That is, an experiment was conducted by excluding a lens array from a conventional reflective screen so that a flip image was not observed by a conventional reflective screen.

Specifically, in order to limit the aperture ratio of the projection lens, a mask having a portion of the central portion thereof opened is provided on the rear surface of a convex Fresnel lens, which is a projection lens, and letters of 'U', 'H' and 'K' So that it is spaced apart from the rear surface of the projection lens. At this time, the corresponding light of the character is incident on and reflected by a mirror and a three-dimensional screen according to an embodiment of the present invention, respectively, and the reflected light is observed by a camera through a beam splitter. The camera observes the reflected light located at the center, left, and right of the point where the beam splitter focuses. As experimental conditions, the focal length of the lens was 152 mm, the aperture size of the lens was 64 mm, and the letters were separated from the lens by 325 mm, 350 mm, and 425 mm, respectively. In addition, the three-dimensional screen according to an embodiment of the present invention is characterized in that each lens of the lens array 100 has a size of 1 mm and a focal length of 3 mm, and a corner cube of the retroreflective film 200 And a size of 0.2 mm was used.

9 shows a photograph of the experimental result according to Fig.

9, the mirror is limited in the range of the viewing window in which the image can be viewed in accordance with the aperture ratio limitation of the projection lens, so that a part of the character is obscured, whereas the three-dimensional screen according to the embodiment of the present invention, Despite the limitation of the aperture ratio, the range of the field of view is not limited and all letters can be observed.

Referring to FIG. 9, in the case of a mirror, the spacing between characters decreases from right to left. On the other hand, a three-dimensional screen according to an embodiment of the present invention narrows the character spacing from left to right. This indicates that the three-dimensional screen according to the embodiment of the present invention reverses the depth sense but can transmit the stereoscopic feeling as it is.

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 exemplary embodiments, but, on the contrary, It will be appreciated that one embodiment is possible. Accordingly, the true scope of the present invention should be determined by the technical idea of the claims.

10: multi-depth object 11: aperture ratio limitation of floating lens
12: floating lens 13: floating image
20: pickup part 21: object
22: lens array 23: photographing element
30: display part 31: projection
32: basic lens 33, 40, 50: screen
41, 42, 51, 100: lens array
51: mirror 200: retroreflective film

Claims (2)

A screen used in a projection type three-dimensional image display system for projecting a three-dimensional image,
A lens array having a plurality of lenses and transmitting the output three-dimensional image; And
And a retroreflective film disposed in parallel to the lens array so as to be spaced apart from the lens array. The method according to claim 1,
The distance between the lens array and the retroreflective film is,
Wherein the focal length of the lens array is not more than twice the focal length of the lens array, except for the focal length of the lens array.

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