JP5397911B2 - Reflective recursive front screen and reflective stereoscopic display screen - Google Patents

Description

The present invention relates to a reflective recursive front screen and a reflective stereoscopic display screen.

Conventionally, there is a screen made of a diffusion film that diffuses incident light from within a specific angle region into the specific angle region.
For example, Patent Document 1 discloses a projection display screen that has a structure in which a plurality of diffusion films are laminated, the diffusion angle regions of the laminated films overlap, and the diffused light intensity distribution characteristics with respect to projector light are uniform. .
Further, Patent Document 2 discloses a projection display screen that includes a diffusion film that allows arbitrary control of the diffused light intensity distribution characteristics and whose diffusion angle region does not change with respect to incident light from a specific angle region. ing.

JP 2007-171523 A JP 2006-84563 A

The screens disclosed in Patent Documents 1 and 2 are capable of displaying high-quality images with little change in brightness depending on the observation angle.
Even if a large number of people project different images on the same screen using a personal projector from the direction they are looking at, such a screen crosstalks with the image projected by another person. There is also a need for a high-quality screen that only you can see.
In addition, a 3D screen that allows the right eye to see the right eye image and the left eye to see the left eye image is also desired by applying the fact that the visible image is switched sharply depending on the viewing angle of the screen.

The present invention has been made in view of the above-described circumstances, and even if a large number of people project different images on the same screen using a personal projector from each viewing direction, the image projected by the other person To provide a reflective recursive front screen that can be seen only by itself without cross-talking with the projected image, and a reflective stereoscopic display screen using the reflective recursive front screen. With the goal.

In order to achieve the above object, a reflective recursive front screen according to the present invention includes a reflective screen having recursive characteristics, and the reflective screen projects an image on which a surface structure of a reflective surface is projected. It is characterized by being a cat-eye lens reflecting screen or a one-dimensional cat-eye lens reflecting screen having a reflection diffusion characteristic of diffusing and reflecting in a specified direction.

In the present invention, the reflective screen has a reflection / diffusion characteristic in which an image on which the surface structure of the reflection surface is projected is diffused and reflected in the direction in which the image is projected. You can see the reflected image.
As a result, conventionally, light is reflected toward the projection lens of the personal projector on which each person is projecting. Therefore, the image is not reflected and cannot be seen by the eyes of the person projecting the image. However, if the image is diffused and reflected in a range including the position of the eyes of the person projecting the image, the person projecting the image can see the image projected by himself / herself.

In addition, since the reflective screen is a cat's eye lens reflective screen, it is possible to express reflective diffusion characteristics with recursion by roughening the surface shape of one or both of the lens surface and the reflective surface. it can.

In addition, the reflective screen is a one-dimensional cat-eye lens reflective screen, so that at least one of the cylindrical lens surface and the cylindrical reflective surface arranged on the focal plane is roughened, thereby providing one-way recurrence. The diffusion characteristics possessed are obtained.

In the reflective recursive front screen according to the present invention, the reflective surface may have a quadratic curved surface asperity.
In this way, the unevenness of the quadratic function curved surface is formed on the reflection surface, so that it has uniform diffusion characteristics within the diffusion angle range, so a uniform image with no brightness unevenness avoiding hot spots is displayed. In addition, the end portion of the diffusion angle has a top-hat diffusion characteristic that does not diffuse steeply, and crosstalk can be avoided.

In the reflective recursive front screen according to the present invention, the reflective screen may have anisotropy in reflection diffusion characteristics.
As described above, the reflective screen has anisotropy in the reflection / diffusion characteristics, so that, for example, the vertical viewing angle and the horizontal viewing angle are independently controlled to be viewed. The light intensity can be concentrated in the direction of the person who is, and the brightness can be increased.

Also, in the reflective stereoscopic display screen according to the present invention, any one of the above-described reflective recursive front screens is formed in a curved state, projects different images from two different directions, and is reflected by the reflective screen. The right eye of the observer is positioned on one side of the boundary between the different images, and the left eye of the observer is positioned on the other side.

In the present invention, the reflection type recursive front screen has a curved surface on which the image is projected, so that the position where all the boundaries of the different images coincide with each other appears. A high-quality stereoscopic image can be seen by installing the observer's right eye on one side of the boundary and the observer's left eye on the other side.

  According to the present invention, even when a plurality of viewers project images on the same reflective recursive front screen from different directions, only the projected images do not cross-talk with images projected by other viewers. Can see.

It is a figure which shows an example of the reflection type recursive front screen by embodiment of this invention. It is a figure explaining a reflection type screen.

Hereinafter, a reflective recursive front screen according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the reflective recursive front screen 1 according to the present embodiment includes a screen laminate 3 in which a plurality of internal refractive index distribution structure diffusion films 2 are laminated, and a reflective type in which the screen laminate 3 is closely laminated. And a screen 4.

The internal refractive index distribution structure diffusing film 2 is formed in an internal refractive index distribution structure, and uniformly diffuses incident light from within a predetermined angle region independently of the incident angle only within the predetermined angle region. Incident light incident from outside the angle range is transmitted through like a glass without being diffused at all.
Here, the predetermined angle region will be described as a diffusion angle region A below.
The plurality of internal refractive index distribution structure diffusion films 2 constituting the screen laminate 3 are laminated so that their diffusion angle regions do not overlap. The screen laminate 3 has a plurality of internal refractive index distribution structure diffusion films 2 that are overlapped with each other so that the diffusion angle areas do not overlap with each other. Can be diffused in the diffusion angle region.

For example, when the screen laminate 3 has a structure in which four diffusion films 2 a to 2 d are laminated, the lateral diffusion angle region Aa of the first internal refractive index distribution structure diffusion film 2 a is −15 ° to 15 °, the second The lateral diffusion angle region Ab of the internal refractive index distribution structure diffusion film 2b is 30 ° to 80 °, the lateral diffusion angle region Ac of the third internal refractive index distribution structure diffusion film 2c is −80 ° to −30 °, and the fourth internal refraction. The longitudinal diffusion angle region Ad of the rate distribution structure diffusion film 2d is set to −15 ° to 15 °.
The structure of the screen laminate 3 may be other than the structure described above.

As shown in FIG. 2, the reflective screen 4 has a two-sided orthogonal mirror film (for example, apex angle 90 ° reflective type, metal film coating, prism sheet) in which the function of the retroreflective mirror is limited to one direction. It is used.
When only the recursiveness in the horizontal direction is sufficient, the mirror structure may be a double mirror film having a simpler structure than a triple mirror screen or a cat's eye lens reflecting screen, which is easy to manufacture and inexpensive. When using a two-sided orthogonal mirror film, recursion is caused by light reflected by the two reflecting mirrors of the two-sided orthogonal mirror film, so that only one of the two reflecting surface shapes is roughened. Diffusion characteristics with recursion are developed. Of course, both sides may be roughened.
The screen laminate 3 and the reflective screen 4 are in close contact with a transparent optical adhesive.

  When one observer projects an image from one direction on the reflective recursive front screen 1 with a personal projector, among the laminated internal refractive index distribution structure diffusion films 2a to 2d, for example, the first internal refractive index. Only the distributed structure diffusion film 2a diffuses the light from this one direction within the incident angle range. The other second to fourth internal refractive index distribution structure diffusing films 2b, 2c, and 2d all exhibit the characteristics of allowing the incident light incident from one direction to pass straight like glass, so that the light is diffused. Therefore, the optical characteristics are the same as when they do not exist.

The exit diffusion of the first internal refractive index distribution structure diffusion film 2a has a uniform diffusion characteristic limited within a limited angle, and the observer is projecting the output diffused light by the reflective screen 4 And the angle of the projection lens of the personal projector with respect to the screen. For this reason, only the observer who is projecting the image can see the image he / she projected.

Note that when another observer projects an image from another direction different from the one observer, only the other internal refractive index distribution structure diffusion film 2 (for example, the second internal refractive index distribution structure diffusion film 2b) is in the other direction. From the incident angle range. The outgoing diffused light returns to the direction of another observer by the retroreflecting mirror of the reflective screen 4. Also in this case, the light is diffused by the angle of the other observer's eyes that are projecting and the projection lens of the personal projector with respect to the screen. For this reason, only the other observer who is projecting the image can see the image projected by himself / herself.

Next, the effect of the above-described reflective recursive front screen will be described with reference to the drawings.
According to the reflective recursive front screen 1 according to the present embodiment, even if a large number of people use the same screen and project different images with a personal projector from the direction they are viewing, they themselves project. The high-quality images can be seen only by yourself without crosstalk with images projected by other than yourself.

Next, a reflective stereoscopic display screen to which the above-described reflective stereoscopic display screen is applied will be described.
The reflective stereoscopic display screen according to the present embodiment utilizes the fact that the boundaries of a plurality of limited diffusion angle regions possessed by the reflective recursive front screen 1 shown in FIG. 1 are steep, By curving the reflective recursive front screen 1 into a curved surface, a binocular or multi-lens reflective stereoscopic display screen without glasses is realized.
The reflection type recursive front screen 1 has a plane on which an image is projected, so that when an observer crosses the screen, the boundary between different images appears to move from the edge of the screen. Since the 3D display screen is formed with a curved surface on which an image is projected, a position where all the boundaries of different images coincide with each other appears. If a viewer's right eye is installed on one side of this boundary and the viewer's left eye is installed on the other side, a high-quality stereoscopic image can be seen.
By creating a plurality of such boundaries, expansion to the multi-view type is also conceivable.
The reflective stereoscopic display screen according to the present embodiment described above can easily project a stereoscopic image without 3D glasses.

As described above, the embodiments of the reflective recursive front screen 1 and the reflective stereoscopic display screen according to the present invention have been described. However, the present invention is not limited to the above-described embodiments, and may be appropriately selected without departing from the scope of the present invention. It can be changed.
For example, in the embodiment described above, a two-surface orthogonal alignment mirror film is used for the reflective screen 4, but a cat's eye lens reflection screen may be used instead of the two-surface orthogonal alignment mirror film. In the case of a cat-eye lens reflecting screen, a diffuse characteristic with recursion can be exhibited by roughening the surface shape of either the lens surface or the reflecting surface or both.

In the embodiment described above, a two-surface orthogonal alignment mirror film is used for the reflective screen 4, but a triple mirror screen (corner cube array) may be used instead of the two-surface orthogonal alignment mirror film.
The reflection surface of the triple mirror has three surfaces, and the retroreflection is realized by the light beam reflected by the three surfaces of the mirror. Therefore, if the surface shape of only one of the three surfaces is roughened, the retroreflection is accompanied. Diffusion characteristics are manifested.

In the above-described embodiment, the two-surface orthogonal alignment mirror film is used for the reflective screen 4, but instead of the two-surface orthogonal alignment mirror film, a one-dimensional cat-eye lens reflection screen (the focal point of the cylindrical lens) is used. A film in which an element having a cylindrical reflection mirror arranged on the surface thereof is arranged in an array like a lenticular lens may be used.

Further, when the reflective screen 4 is a one-dimensional cat-eye lens reflective screen, the surface of the cylindrical lens and / or the surface of the cylindrical reflective surface arranged at the focal plane is roughened, thereby recurring in one direction. A diffusion characteristic having
In addition, since the two-surface orthogonal matching mirror film can reflect all the incident light only in the case of front incidence in the incident direction, some light is reflected by two reflection surfaces when incident from other than the front. Only one of them may hit, and the reflection efficiency may be reduced, and stray light may be generated, causing crosstalk. On the other hand, if the reflective screen 4 is a one-dimensional cat-eye lens reflective screen, the opening of the cylindrical lens covers the entire screen, and in the case of incidence into the NA of the lens, all light is incident in the incident direction. Can be reflected.

In the above-described embodiment, a two-surface orthogonal alignment mirror film is used for the reflection-type screen 4, but a reflection type in which irregularities of a quadratic function curved surface are formed on the surface instead of the two-surface orthogonal alignment mirror film. It may be a screen.
In order to avoid hot spots and display a uniform image without uneven brightness, it is necessary to diffuse uniformly within the diffusion angle range, and to avoid crosstalk, the end of the diffusion angle is steep. It is desirable to develop a top hat-like diffusion characteristic that does not diffuse.

And even as a reflective stereoscopic display screen that does not use 3D glasses, it is top for separating the observer's right eye diffusion angle range and left eye diffusion angle range without crosstalk, and to show a uniform image without hot spots. It is important to form the reflective surface of the reflective screen 4 in a surface shape that realizes a hat-like diffusion characteristic.
Specifically, a surface shape that realizes such top-hat diffusion characteristics is preferably a shape in which parabolic reflection surfaces of a quadratic curved surface are formed in an array shape and are smoothly connected using concave and convex surfaces. Then, by randomly distributing the sizes of the respective parabolic reflectors, it is possible to avoid luminance unevenness and color unevenness with respect to the angle due to interference, and it is possible to obtain ideal top-hat diffusion characteristics as a reflection type. . The diffusion width of the top hat diffusion characteristic can also be realized with very good controllability depending on the shape.

Further, the reflection type screen 4 described above may have anisotropy in reflection diffusion characteristics. For example, the vertical viewing angle and the lateral viewing angle can be controlled to increase the brightness by concentrating the light intensity in the direction of the observer.
In addition, in the reflection type stereoscopic display screen, when it is desired to make the parallax change in the horizontal direction fine and make the parallax change in the vertical direction rough, or when not displaying the vertical parallax, the diffusion angle is reduced in the horizontal direction, It can diffuse greatly in the vertical direction.
Specifically, the vertical diffusion angle and the horizontal diffusion angle of the top hat diffusion characteristics can be controlled by changing the opening of the parabolic reflector having a quadric surface in the vertical direction and the horizontal direction. Moreover, you may control the curvature of the vertical direction and the curvature of a horizontal direction of the parabolic reflector of a quadric surface, respectively.

DESCRIPTION OF SYMBOLS 1 Reflective front screen 2 Internal refractive index distribution structure diffusion film 3 Screen laminated body 4 Reflective screen

Claims (4)

A reflection type screen having recursive characteristics, the reflection type screen reflecting a cat's eye lens having a reflection diffusion characteristic of reflecting and reflecting an image in which a surface structure of a reflection surface is projected in a direction in which the image is projected A reflective recursive front screen, characterized in that it is a screen or a one-dimensional cat's eye lens reflective screen. The reflective recursive front screen according to claim 1 , wherein the reflective surface has irregularities of a quadratic function curved surface. The reflection type recursive front screen according to claim 1 , wherein the reflection type screen has anisotropy in reflection diffusion characteristics. The reflective recursive front screen according to claim 1 is formed in a curved state, projects different images from two different directions, and a boundary between the different images reflected by the reflective screen. A reflective three-dimensional display screen, wherein the viewer's right eye is positioned on one side and the viewer's left eye is positioned on the other side.

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