JP2009271263A - Screen for front projection using one side specular serration reflecting plate, and front projection type display and information processing apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more effectively reflect image light from a front projector on a surface side by a screen, so as to view a more bright image, and further, to more effectively prevent the phenomenon that illumination light at the inside of a chamber or sunlight at the outside of a room are reflected by a screen on the surface thereof, and the visibility of an image is reduced. <P>SOLUTION: The screen 2a for a front projection using a one side specular serration reflecting plate is formed by: a light diffusion layer 4 having properties that only light made incident from a specified angle region is diffusely transmitted and light made incident from the angle region other than that is made to go straight and is transmitted; a light transmission layer 6 in which areas 8 for mirror-formation having a certain inclination at the backside and areas 10 for mirror-nonformation having an inclination different from that are alternately arranged along the vertical direction, so as to form a face bent into serration, and joined to the backside of the light diffusion layer 4 at the face on the side opposite to the face; and specular reflective films 10, 10 formed every areas 8, 8 for mirror-formation and made of a material having reflectivity. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention includes a front projection screen using a one-sided mirror sawtooth reflector, and a front projection type display device in which a front projector is disposed such that the optical axis thereof is directed obliquely upward with respect to the front projection screen, The present invention relates to an information processing apparatus including the screen and the front projector.

In the front projection type display device, a front projection screen is arranged in a substantially vertical direction, and a front projector is arranged on the surface side of the screen so that image light is irradiated obliquely upward with respect to the surface. The image light from the front projector is reflected by the screen so that the image is viewed from the front side of the screen (Patent Document 1).
There are various types of such front projection screens, and FIG. 7 is a sectional view showing an example thereof.

In FIG. 7, a is a resin screen called a white mat, for example, and the right side surface in FIG. 7 is a surface (front surface) that reflects image light from a front projector (d), which will be described later. The minute diffusion areas b and the minute unnecessary areas c are alternately arranged in the vertical direction. The direction in which the areas b and c are alternately arranged is referred to as an area alternate arrangement direction.
The arrangement pitch of the area alternate arrangement is, for example, about 100 μm. Each minute diffusion area b is inclined by about 10 °, for example, obliquely downward with respect to the entire surface of the screen a. The reason why each minute diffusion area b is tilted in this way is to allow the observer to visually recognize the image by allowing the image light from the obliquely lower front projector d to be reflected to the front side. Each minute unnecessary area c is formed to be substantially horizontal or obliquely upward.

Reference numeral d denotes a front projector, which is arranged obliquely below the surface side of the screen a, has an optical axis obliquely upward, and irradiates image light onto the screen a from obliquely below.
e is an eye of an observer who is located on the surface side of the screen a and visually recognizes an image in front of the screen a from image light irradiated on the surface of the screen a.
Each minute diffusion area b receives image light from the front projector d and diffusely reflects it on the surface side. Accordingly, an observer in front of the screen a can recognize an image by viewing the diffusely reflected light.

In some cases, as shown in FIG. 7, a light absorption film h made of, for example, a black resin is formed on the surface of each minute unnecessary area c. For example, the light from the indoor lighting device f or the sun is reflected on the surface side of the screen a together with the image light so that the indoor illumination or the sun is visually recognized together with the image, and the visibility of the image is deteriorated. It is for preventing.
JP 2008-020485 A

However, the conventional front projection screen as shown in FIG. 7 has a problem that it is difficult to display a clear image in a bright environment.
This is because, according to such a conventional technique, since the screen a is made of a resin called white mat, light from the illumination device f is diffusely reflected by the screen a.

  The present invention has been made to solve such problems, and a first object is to reduce the visibility of the image by reflecting indoor illumination light or outdoor sunlight to the surface side by the screen. The second purpose is to enable the image light from the front projector to be reflected more effectively on the surface side by the screen so that a brighter image can be visually recognized. .

  The front projection screen using the one-sided mirror sawtooth reflector according to claim 1 diffuses and transmits only the light incident from a specific angle region, and linearly transmits the light incident from the other angle region; The mirror forming area having a predetermined inclination on the back side and the mirror non-forming area having a predetermined inclination different from that are alternately arranged along a predetermined direction to form a surface that is bent in a sawtooth shape. A light transmissive layer bonded to the back side of the light diffusion layer on the opposite surface, and a specular reflection film made of a reflective material formed on the back surface of each mirror forming area. Features.

  The front projection screen using the one-side specular serrated reflector according to claim 2 diffuses and transmits only light incident from a specific angle region, and linearly transmits light incident from other angle regions; The mirror forming area having a predetermined inclination on the back side and the mirror non-forming area having a predetermined inclination different from that are alternately arranged along a predetermined direction to form a surface that is bent in a sawtooth shape. A light transmissive layer bonded to the back side of the light diffusion layer on the opposite surface, and a specular reflection film made of a reflective material formed on the back surface of each mirror forming area, The back surface of each of these mirror non-forming areas is processed so as to have light diffusibility.

The front projection screen using the one-side specular sawtooth reflector according to claim 3 diffuses and transmits only light incident from a specific angle region, and linearly transmits light incident from other angle regions; The mirror forming area having a predetermined inclination on the back side and the mirror non-forming area having a predetermined inclination different from that are alternately arranged along a predetermined direction to form a surface that is bent in a sawtooth shape. A light transmissive layer bonded to the back side of the light diffusion layer on the opposite surface, a specular reflective film made of a reflective material formed on the back surface of each mirror forming area, and the light transmissive layer And a refractive index adjusting film having a refractive index similar to that of the light transmission film, which is formed so as to cover each mirror reflecting film and each non-mirror forming area back surface.
The front projection screen using the one-side mirror-like sawtooth reflector according to claim 4 is the front projection screen using the one-side mirror-like sawtooth-like reflector according to claim 3, wherein a light absorbing film is provided on the back surface of the refractive index adjusting film. Is formed.

  The front projection screen using the one-side specular serrated reflector according to claim 5 diffuses and transmits only light incident from a specific angle region, and linearly transmits light incident from other angle regions; The mirror forming area having a predetermined inclination on the back side and the mirror non-forming area having a predetermined inclination different from that are alternately arranged along a predetermined direction to form a surface that is bent in a sawtooth shape. A light transmissive layer bonded to the back side of the light diffusion layer on the opposite surface, a light absorbing film formed on the back surface of each non-mirror forming area, each mirror reflective film of the light transmissive layer, and And a refractive index adjusting film formed so as to cover each light absorbing film and having a refractive index approximate to that of the light transmitting film.

A front projection type display device using the one-side specular serrated reflector according to claim 6 includes a front projection screen using the one-side specular serrated reflector according to any one of claims 1 to 5, and the front projection. A front projector that is disposed obliquely below the front side of the screen for projecting image light on the front side of the screen,
The image from the front projector diffused from the surface of the light diffusing layer is θpt, the lower limit is θpb, and the upper limit of the incident angle range (see θpb to θpt in FIG. 4) of the image light of the front projector to the surface of the light diffusing layer. When the upper limit of the light diffusion angle region (see θdb to θdt in FIG. 4) is θdt and the lower limit is θdb,
−90 ° ≦ θpb ≦ θpt ≦ θdb ≦ θdt ≦ 90 °
It is characterized by satisfying the following conditions.

A front projection type display device according to a seventh aspect of the present invention is a front projection screen using the one-side specular sawtooth reflector according to any one of the first to fifth aspects, and an obliquely lower front surface of the front projection screen. And a front projector that projects image light to the front of the screen,
The angle of the surface of each mirror non-forming area with respect to the normal line of the light diffusion layer is θ ₂ , and the angle of the light passing through the upper limit of the incident angle range of the image light projected from the front projector with respect to the normal line in the light transmission layer Is θpt ′,
θ ₂ > θpt′−20 °
It is characterized by satisfying the following conditions.

A front projection type display device according to claim 8 is disposed on the front projection screen using the one-side specular sawtooth reflector according to any one of claims 1 to 5 and obliquely below the front of the front projection screen. And a front projector that projects image light to the front of the screen,
The image from the front projector diffused from the surface of the light diffusing layer is θpt, the lower limit is θpb, and the upper limit of the incident angle range (see θpb to θpt in FIG. 4) of the image light of the front projector to the surface of the light diffusing layer. When the upper limit of the light diffusion angle region (see θdb to θdt in FIG. 4) is θdt and the lower limit is θdb,
−90 ° ≦ θpb ≦ θpt ≦ θdb ≦ θdt ≦ 90 °
While satisfying the conditions of
The angle of the surface of each mirror non-forming area with respect to the normal line of the light diffusion layer is θ ₂ , and the angle of the light passing through the upper limit of the incident angle range of the image light projected from the front projector with respect to the normal line in the light transmission layer Is θpt ′,
θ ₂ > θpt′−20 °
It is also characterized by satisfying the above conditions.

The information processing apparatus according to claim 9 is the front projection type display apparatus according to claim 6, 7 or 8, wherein the front projector is provided at a plurality of different positions, and the one-side mirror sawtooth is generated by image light of the plurality of front projectors. A stereoscopic image is displayed on a front projection screen using a reflector.
An information processing apparatus according to a tenth aspect of the present invention includes a main body that performs information processing, a display that displays an image corresponding to an image signal generated by the main body, and an image signal received from the main body to generate image light. A front projector, wherein the display comprises a screen for front projection using the one-side specular sawtooth reflector according to any one of claims 1 to 5, wherein the front projector transmits the image light to the front projection. This is characterized in that an image is displayed on the front projection screen by irradiating it toward the screen.
The information processing apparatus according to claim 11 is the information processing apparatus according to claim 10, wherein the front projector is provided at a plurality of different positions, and the one-side specular sawtooth reflector is used by image light of the plurality of front projectors. A stereoscopic image is displayed on the work screen.

  According to the front projection screen using the one-side specular serrated reflector according to claim 1, only the light incident from a specific angle region is diffused and transmitted, and the light diffused to transmit light incident from the other angle region straightly. Only the projector light is diffused and reflected on the surface side by the specular reflection film for each mirror forming area of the light transmission layer bonded to the back side of the layer and the light diffusion layer, so that indoor illumination light or outdoor sunlight is screened. Therefore, it is possible to more effectively prevent the visibility of the image from being reflected on the surface side of the image.

According to the front projection screen using the one-side specular serrated reflector according to claim 2, as in the front projection screen using the one-side specular serrated reflector according to claim 1, only the projector light is directed to the front side. It is possible to more effectively prevent the indoor illumination light or outdoor sunlight from being reflected on the surface side by the screen and reducing the image visibility.
Furthermore, since the surface of each mirror non-forming area is processed so as to have light diffusibility, the light incident on each mirror non-forming area is dispersed, and the proportion of the light entering the observer in the light is determined. Thus, the effect of effectively preventing indoor illumination light or outdoor sunlight from being reflected on the surface side by the screen and reducing the visibility of the image can be further enhanced.

According to the front projection screen using the one-side specular serrated reflector according to claim 3, as in the case of the front projection screen according to claims 1 and 2, only the projector light is diffusely reflected to the surface side, and the room lighting is performed. It is possible to more effectively prevent light or outdoor sunlight from being reflected on the surface side by the screen and reducing the visibility of the image.
Furthermore, since the refractive index adjustment film having a refractive index approximate to that of the light transmission film is formed so as to cover each mirror reflection film and each mirror non-formation area back surface of the light transmission layer, for example, incident on the mirror non-formation area Indoor illumination light or outdoor sunlight can be transmitted to the refractive index adjusting film without being reflected.
Therefore, it is possible to further enhance the effect of more effectively preventing indoor illumination light or outdoor sunlight from being reflected on the surface side by the screen and reducing the visibility of the image.

According to the front projection screen using the one-side specular serrated reflector according to claim 4, in the front projection screen according to claim 3, since the light absorption film is formed on the back surface of the refractive index adjustment film, no mirror is formed. For example, indoor illumination light or outdoor sunlight incident on the work area can be absorbed by the light absorption film.
Therefore, not only can the effect produced by the front projection screen using the one-side mirror-like serrated reflector according to claim 3 be enjoyed, but also the light absorbing film in which the light transmitted through the refractive index adjusting film is formed on the back surface thereof. For example, indoor illumination light or outdoor sunlight incident on the non-mirror formation area can be more completely absorbed by the light absorption film.

  According to the front projection screen using the one-side specular serrated reflector according to claim 5, the refractive index adjustment film having a refractive index approximate to that of the light transmission film is used as each mirror reflection film and each light absorption of the light transmission layer. Since it is formed so as to cover the film, for example, indoor illumination light or outdoor sunlight incident on the non-mirror forming area can be absorbed more completely by the light absorption film.

  According to the front projection type display device of the sixth aspect, the front projection screen according to any one of the first to fifth aspects is used as the front projection screen using the one-side specular serrated reflector, and the image of the front projector is used. The upper limit of the incident angle range of light with respect to the surface of the light diffusion layer is θpt, the lower limit is θpb, the upper limit of the diffusion angle region of image light from the front projector diffused from the surface of the light diffusion layer is θdt, and the lower limit is θdb Then, since the condition of −90 ° ≦ θpb ≦ θpt ≦ θdb ≦ θdt ≦ 90 ° is satisfied, the incident angle region of the image light directed obliquely upward from the front projector and the diffusion angle region of the image light Can be displayed without overlapping, and as a result, any one of claims 1 to 5 It is possible to receive the effect of the clean is achieved.

According to the front projection type display device of claim 7, the angle in the area alternate arrangement direction with respect to the normal line of the light diffusion layer of the surface of each non-mirror forming area is set as the area alternate arrangement of the optical axes of the front projector. Since the angle is set to −20 ° or more with respect to the upper limit angle in the direction, the light entering the non-mirror forming area out of the light from the front projector can be completely or almost completely eliminated. The effect which the screen in any one of Claims 1-5 show | plays can be enjoyed.
According to the front projection type display device of the eighth aspect, since both of the conditions of the front projection type display device of the seventh and eighth aspects are satisfied, the incident angle region of the image light and the image light directed obliquely upward from the front projector Therefore, it is possible to achieve a good display without overlapping with the diffusion angle region of the light, and to completely or almost completely eliminate the light incident on the non-mirror formation area among the light from the front projector. Furthermore, the effect which the screen in any one of Claims 1-5 show | plays can be enjoyed.
According to an information processing apparatus of a ninth aspect, in the front projection type display apparatus according to any one of the sixth to eighth aspects, the front projector is provided at a plurality of different positions, and the one-side specular sawtooth is generated by image light of the plurality of front projectors. Since the stereoscopic image is displayed on the front projection screen using the shaped reflector, the stereoscopic image can be displayed on the front projection screen.

According to the information processing apparatus of the tenth aspect, since the display is configured by the front projection screen using the one-side specular serrated reflector according to any one of the first to fifth aspects, the front of any one of the first to fifth aspects. The effect of the projection screen can be enjoyed.
According to the information processing apparatus of claim 11, in the information processing apparatus of claim 10, the front projector is provided at a plurality of different positions, and the one-side specular sawtooth reflector is used by image light of the plurality of front projectors. Since the stereoscopic image is displayed on the front projection screen, the stereoscopic image can be reproduced.

In the present invention, basically, as a front projection screen, a light diffusion layer, a mirror forming area having a certain inclination on the back side, and a mirror non-forming area having a different inclination are alternately arranged along a predetermined direction. A surface that is bent in a sawtooth shape is formed, a light transmission layer that is joined to the back side of the light diffusion layer at the surface opposite to the surface, and is formed for each mirror forming area. A mirror-type reflective film made of a reflective material and a type using a single-sided mirror-like sawtooth reflector having a reflective surface, and the light diffusion layer diffuses and transmits only light incident from a specific angle region. However, a diffusion sheet made of resin is preferable. Such a diffusion film is composed of a periodic structure of a medium having two different refractive indexes, and is a volume hologram diffusion film that diffuses incident light from within a specific angular region into a specific angular region (see “Okita et al.”). : Sumitomo Chemical 1991-1, p. 37-48 ").
The light transmitting layer uses, for example, a transparent resin as a material, and a mirror forming area having a certain inclination on the back side and a non-mirror forming area having a different inclination are predetermined by etching or molding technology. It can be formed in the above-mentioned shape in which a surface that is alternately arranged along the direction and is bent in a sawtooth shape is formed.

The specular reflection film is made of metal, such as aluminum Al or silver Ag, and is deposited or sputtered at a specific angle only on each of the mirror forming areas on the back surface of the light transmission layer formed in the above shape by etching or molding. Can be formed.
When the non-mirror-formed area on the back surface of the light transmission layer is made to have light diffusibility, reflection of light to the front side can be reduced. For this purpose, the surface of the area should be roughened. Roughening can be performed by forming a specular reflection film and then sputtering particles, for example, on the back surface of the light transmission layer or by immersing the back surface in an etching solution.

Further, if a light absorption film on the back surface of the light transmission layer is provided, light passing through the non-mirror-forming area can be absorbed, and this method is preferable. In that case, the light absorption film can be formed by applying a resin having a dark color such as black and having a strong light absorption property.
Further, by forming a refractive index adjusting film on the back surface of the light transmitting layer, light incident on the mirror non-formation area on the back surface of the light transmitting layer can be advanced to the back side. May be formed of a highly transparent resin having a refractive index comparable to that of the light transmission layer.

Further, by combining light diffusibility or providing a light absorbing film in the non-mirror-forming area on the back surface of the light transmitting layer and forming a refractive index adjusting film on the back surface of the light transmitting layer, Light incident on the formation area can be made to travel more perfectly to the back side, and reflection to the front side can be prevented more perfectly.
When the number of front projectors is one, a normal planar image (two-dimensional image), that is, an image having no three-dimensionality, is displayed. However, the number of front projectors is two, and the arrangement position is set. If the two front projectors are appropriately separated and the image light for stereoscopic display is irradiated from the two front projectors to one front projection screen, a stereoscopic image (three-dimensional image) can be displayed.
Further, the front projection type display device of the present invention can be applied to a display of a laptop type or notebook type personal computer or other various information processing devices, for example.

Hereinafter, the details of the present invention will be described based on illustrated embodiments.
FIGS. 1A to 1C are cross-sectional views cut vertically, showing different examples 2a to 2c of the front projection screen of the present invention.
First, a first example 2a of a front projection screen will be described with reference to FIG.
This front projection screen 2a is a screen using a one-sided mirror-like serrated reflector, and includes a diffusion layer 4, a light transmission layer 6 bonded to the back surface (rear surface) of this diffusion layer 4, and this light It consists of specular reflection films 14, 14,... Formed in the mirror formation areas 8, 8,.

The diffusion layer 4 is made of, for example, a diffusion sheet, and has a property of diffusing and transmitting only light incident from a specific angle region, and linearly transmitting light incident from other angle regions. Here, the specific angle region is an incident angle range of the image light of the front projector with respect to the surface of the light diffusion layer, or a diffusion angle region of the image light from the front projector diffused from the surface of the light diffusion layer.
When the incident angle range of the front projector is the diffusion transmission angle region of the diffusion sheet, the projector light diffuses and transmits through the diffusion sheet when incident on the screen, is reflected by a specular reflection film described later, and passes straight through the diffusion sheet when exiting the screen. When the diffusion angle area of the image light from the front projector is the diffusion transmission angle area of the diffusion sheet, the projector light diffuses and transmits through the diffusion sheet when incident on the screen, is reflected by a specular reflection film, which will be described later, and passes through the diffusion sheet when exiting the screen. Diffuse and transmit. Therefore, in the entire screen, the projector light is diffusely reflected in the diffusion angle region of the image light from the front projector in any of the cases described above.
On the other hand, the illumination light incident from the diffusion angle region of the image light from the front projector is diffusely reflected in the incident angle range of the front projector in either case. Further, the illumination light incident from outside the incident angle range of the front projector and the diffusion angle region of the image light from the front projector is reflected straight back outside the incident angle range of the front projector and the diffusion angle region of the image light from the front projector. It will be.
The light transmission layer 6 has a flat front surface (front side), and the flat surface is bonded to the rear surface (back side) of the diffusion layer 4. The rear side (back side) of the mirror forming area 8 is inclined so as to be closer to the rear side (back side) as it goes down from the vertical direction, and the lower side from the horizontal direction. The mirror non-forming areas 10 that are inclined so as to approach the front (front side) are alternately arranged to form a saw-toothed surface.

And each mirror formation area 10,10, ... among the back surfaces of the light transmissive layer 6 is made into the rough surface 12, and is made to have light diffusivity. This is to completely eliminate the possibility that the incident light is collected in a specific direction and reflected to the front (front) side, and diffuses and passes to the rear side.
Each of the specular reflection films 14, 14,... Is formed on each of the mirror forming areas 8, 8,..., And is incident on the areas 8, 8,. The image light from (not shown in FIG. 1) is mirror-reflected to the front side (front side) to create an image that can be viewed by the user on the front side. Here, the reflectivity of the specular reflection film is preferably as high as possible. However, it is generally about 80 to 90%, and at least 50% or more at which half of the total amount of light is effectively used is necessary.

Further, light incident on the front projection screen 2a obliquely downward by sunlight or illumination light is mainly incident on each non-mirror forming area 10, 10,..., And is diffused there and transmitted to the rear side.
Therefore, according to such a front projection screen 2a, the image light from the front projector located obliquely in front lower side is reflected to the front side by the respective specular reflection films 14, 14,. The sunlight and illumination light on the upper front side can be diffused to the rear side of the screen 2a through each of the non-mirror forming areas 10, 10,... Can do.

2A to 2C are cross-sectional views showing a method of forming the light transmission layer 6 and the specular reflection films 14, 14,... Of the front projection screen 2a in the order of steps.
(A) For example, the light transmitting layer 6 having a serrated surface by alternately arranging the mirror forming areas 8 and the non-mirror forming areas 10 on the rear surface (back surface) by molding or the like. The mirror reflection films 14, 14,... Are formed by preparing and rearwardly facing the surface and subjecting the surface to anisotropic sputtering with aluminum Al or silver Ag. The direction of the sputtering is made to coincide with the surface direction of each of the mirror non-forming areas 10, 10,.

(B) Then, as shown in FIG. 2 (B), the reflecting film 14 is not formed in each mirror non-forming area 10, 10,..., And each mirror-embedding forming area 10, 10,. The reflective films 14, 14,... Can be formed only on the top.
(C) Thereafter, the rear surface (back surface) of the light transmissive layer 6 made of resin is treated with a liquid that corrodes to roughen the areas 10, 10,.

Thereby, the back surface of each mirror non-forming area 10, 10,... Is roughened, and each mirror forming area 8, 8,. The formed light transmission layer 6 is completed.
Thereafter, when the diffusion layer 4 made of, for example, a diffusion sheet is adhered to the front surface (front surface) of the light transmission layer 6, a front projection screen 2a shown in FIG. 1A is completed.

Next, the front projection screen 2b shown in FIG. 1B will be described.
In this screen 2b, the diffusion layer 4 is bonded to the front surface (front surface) of the light transmission layer 6, and the mirror forming areas 8, 8,... Have mirror reflection films 14, 14,. It is the same as the front projection screen 2a shown in FIG. 1A in that it is formed, but differs in the following two points.
First, the mirror non-forming areas 10, 10,... Are not roughened.
Second, a refractive index adjusting film 16 is formed on the entire back surface of the light transmission layer 6, and a light absorbing film 18 is applied to the rear surface of the refractive index adjusting film 16.
However, regarding the first difference, even if each mirror non-forming area 10, 10,... Is roughened, it does not adversely affect the effect of the present invention.

  The refractive index adjusting film 16 is made of a transparent resin having the same refractive index as that of the light transmission layer 6. Therefore, the light from the front side incident on each mirror non-forming area 10, 10,... Is transmitted through the rear light transmission layer 6 without being reflected by the areas 10, 10,. . Here, the lower the refractive index of the matching, the better. However, in general, there is an interface reflection with a reflectance of several percent at the time of vertical incidence, and the reflectance at which half of the total light quantity is reflected at the time of vertical incidence at worst. 50% or less is required. The light absorbing film 18 is made of a resin having a strong light absorbing property such as black, and absorbs light transmitted through the light transmitting layer 6. Here, the higher the absorptance of the light absorption film, the better. However, in general, there is a reflection of several percent, and at least 50% of the absorptance is required to absorb at least half of the total amount of light.

  Also by such a front projection screen 2b, image light from a front projector (not shown in FIG. 1) located obliquely in front lower side is reflected and displayed by the respective specular reflection films 14, 14,. An image is formed, and sunlight and illumination light from the upper front side are transmitted through each non-mirror forming area 10, 10,... Without causing reflection, and absorbed by the light absorption film 18. Thus, it is possible to satisfactorily prevent the visual recognition of the image from being hindered.

Next, the front projection screen 2c shown in FIG. 1C will be described.
In this screen 2c, the diffusion layer 4 is adhered to the front surface (front surface) of the light transmission layer 6, and each mirror forming area 8, 8,... Has mirror reflection films 14, 14,. Although common to the front projection screen 2a shown in FIG. 1A in that it is formed, each non-mirror forming area 10, 10,... Is not roughened and absorbs light on the back surface thereof. It differs in that the films 18, 18,... Are formed. However, regarding this difference, even if each mirror non-forming area 10, 10,... Is roughened, the effect of the present invention is not adversely affected.

According to such a front projection screen 2c, the image light from the front projector located obliquely in front lower side is reflected to the front side by the respective specular reflection films 14, 14,... Sunlight and illumination light from the upper side can be absorbed by the light absorption films 20, 20,... Formed in the respective mirror non-forming areas 10, 10,. However, regarding the light absorbing film, not only the mirror non-forming areas 10, 10,... But also a part or the whole of the mirror reflection film on the side opposite to the projector side has an adverse effect on the effect of the present invention. Absent.
Therefore, it is possible to prevent a good image from being visually recognized.

FIG. 3 is a configuration diagram showing a schematic configuration of one embodiment of the front projection type display device of the present invention by cutting the front projection screen vertically.
Reference numeral 2 denotes a front projection screen, for example, one of the front projection screens 2a to 2d shown in FIGS.
A front projector 22 is disposed obliquely below the front side of the front projection screen 2 and irradiates the front surface of the front projection screen 2 with image light.
E is the eyes of the user (person) viewing the image displayed on the front projection screen 2, and S is the sun, which is a source of light that becomes noise (miscellaneous light) for image display. It should be noted that when the information processing apparatus is used indoors, the illumination light source replaces the sun S.

FIG. 4 is a vertical cross-sectional view cut in a vertical direction for explaining in detail the arrangement angle of the projector 22 of the front projection type display device with respect to the front projection screen 2, the direction of the optical axis of the image light, the diffusion angle region, and the like. It is.
In FIG. 4, the front projection screen 2 shows only the diffusion layer 4 and the light transmission layer 6 for the sake of convenience, and the illustration of other members is omitted.

In the figure, θ ₁ is an angle with respect to the horizontal plane (dashed line) of the mirror forming area 8, and θ ₂ is an angle with respect to the horizontal plane (dashed line) of the non-mirror forming area 10.
θp is an incident angle of the image light emitted from the front projector 22 and incident on the front projection screen 2 [an angle with respect to the horizontal plane (dashed line)], θpb is a lower boundary angle of an incident angle region of the image light from the front projector 22, θpt is the upper boundary angle of the incident angle region.

.theta.p 'is the angle of the image light incident on the front projection screen 2 with respect to the horizontal plane inside the light transmission layer 6, and .theta.d' is incident on each mirror forming area 8, 8,... The angle of the image light reflected by the reflection film 14 with respect to the horizontal plane inside the light transmission layer 6, θd is the angle with respect to the horizontal plane of the image light transmitted through the light transmission layer 6 and emitted from the diffusion layer 4, and θdb is the diffusion of the image light. The lower boundary angle, θdt, of the angle region is the upper boundary angle of the image light diffusion angle region.
θo is an angle with respect to a horizontal plane (indicated by a one-dot chain line) of the angle at which the observer exists, θob is a lower boundary angle of the observation angle range, and θot is an upper limit angle of the observation angle range.

Here, the diffusion angle region is considered.
In general, θdt> θot and θdb <θob.
The angle of the image light passing through the lower boundary (lower limit) angle θpb of the incident angle region with respect to the horizontal plane in the light transmission layer 6 is θpb ′, and the light transmission layer of image light passing through the upper boundary (upper limit) angle θpt. 6 is θpt ′, and the lower boundary (lower limit) angle θp ′ of the image light reflected in the mirror-forming area 8 with respect to the horizontal plane in the light transmission layer 6 is θpb ′, and the upper side of the angle θp ′. Let the boundary (upper limit) angle be θpt ′.

The above θ _{1, that} is, the upper limit, θ ₁ max, and lower limit θ ₁ min of the angle with respect to the horizontal plane (one-dot chain line) of the mirror forming area 8 must satisfy the condition represented by the following expression.
θ ₁ max = (θpb ′ + θdb ′) / 2−90 °
θ ₁ min = (θpt ′ + θdt ′) / 2−90 °
Otherwise, the image light within the incident angle range from the front projector 22 does not enter the mirror forming areas 8, 8,... Effectively. However, for the convenience of design or production, there is a case where it is not effective reflection and it is unavoidable even if some projector light is wasted. Even in such a case, it is desirable that at least 50% of the light incident from the incident angle range of the front projector is diffusely reflected in the diffusion angle region of the image light from the front projector.

Also, θdb is larger than θpt, that is,
θpt <θdb
It is preferable that
Otherwise, that is, if θpt> θdb, the incident angle region of the image light obliquely upward from the front projector 22 partially overlaps with the diffusion angle region of the image light, and good display cannot be performed. It is.

Further, the θ ₂ is larger than θpt′−20 °, that is,
θ ₂ > θpt′−20 °
It is preferable that
This is because, first, if θ ₂ is set to θpt ′ or more, the possibility that the image light from the front projector 22 enters the mirror non-forming area 10, 10,. This is because it can be completely eliminated.
Next, even if it is smaller than θpt ′, if it is about 20 °, the loss of image light can be made extremely small.

Note that the above condition is satisfied even if the positions in the horizontal direction are changed.
Also, it has been assumed that projector light is incident from below the screen and observed from the front. However, even when the projector light is incident from above and observed from the front, the coordinates are taken upside down. The argument holds. Furthermore, the same argument can be made not only by turning upside down but also by taking coordinates with respect to left and right or diagonal.
In the present embodiment, the number of front projectors 22 is one. However, the number of the two front projectors 22 is set to two, the arrangement positions thereof are appropriately separated, and the two front projectors are stereoscopically displayed on one front projection screen. A stereoscopic image (three-dimensional image) may be displayed by irradiating image light for use.

5A and 5B are perspective views showing different examples 40a and 40b, respectively, in which the present invention is applied to a laptop or notebook personal computer which is a kind of information processing apparatus.
Reference numerals 42 and 42 denote main bodies of the computers 40a and 40b, and 44 and 44 denote displays of the computers 40a and 40b, each of which includes a front projection screen according to the present invention, for example, the front projection screens 2a, 2b, 2c, and 2d.

46, 46, 46 are front projectors arranged on the main bodies 42, 42 of the computers 40a, 40b, and irradiate image light onto the front projection screens 44, 44 forming a display for display.
A personal computer 40a shown in FIG. 5A has one front projector 46 and displays a normal two-dimensional image.

On the other hand, in the personal computer 40b shown in FIG. 5B, the number of front projectors 46, 46 is two, and the arrangement positions of the front projectors 46, 46 are appropriately separated in the left-right direction. A (stereoscopic) image is displayed.
As described above, the present invention can be applied to a laptop or notebook personal computer.

FIG. 6 is a perspective view showing an example in which the present invention is applied to an information terminal device which is another type of information processing apparatus.
In the figure, 50 is an information terminal device main body having a photographing function, 52 is electrically connected to the main body 50 and receives image signals from the main body 50 to generate image light, and 54 is the front projector 52. The display screen of the information terminal device 50 is formed by a front projection screen that receives image light from the screen.

H ₁ is a subject, and H ₂ is an image of the subject displayed on the front projection screen 54.
Thus, the present invention can also be applied to information terminal equipment.
Further, to enable a stereoscopic image to be displayed by making the number of front projectors plural, as shown in FIG. 3 using a front projection screen using a one-sided specular sawtooth reflector as shown in FIG. This can also be done in a type of front projection display.

  The present invention uses a display element such as a liquid crystal display element, a front projection screen using a one-sided mirror-like serrated reflector, and an optical axis that is inclined in an oblique direction, for example, an obliquely upward direction with respect to the front projection screen. There is industrial applicability to a front projection type display device having a front projector disposed therein and an information processing device having the screen and the front projector.

(A)-(C) are sectional drawings cut | disconnected perpendicularly which show each another example of the screen for front projections of this invention. (A)-(C) are sectional drawings which show the formation method of the light transmissive layer of a screen for front projections, and a specular reflective film in order of a process. It is a block diagram which shows the schematic structure of one Example of the front projection type display apparatus of this invention cut | disconnected perpendicularly | vertically about the screen for front projection. FIG. 4 is a cross-sectional view cut in a vertical direction illustrating in detail the arrangement angle of the projector with respect to the front projection screen, the direction of the optical axis of the image light, the diffusion angle region, and the like of the front projection type display device of FIG. 3. (A), (B) is a perspective view which shows another example of what applied this invention to the laptop type | mold or notebook type personal computer. It is a perspective view which shows one example which applied this invention to the information terminal device. It is sectional drawing which shows one prior art example of the screen for front projection of the front projection type display apparatus for demonstrating background art.

Explanation of symbols

2, 2a, 2b, 2c, 2d ... front projection screen,
4 ... diffusion layer, 6 ... light transmission layer, 8 ... mirror formation area,
10 ... non-mirror forming area, 12 ... rough surface for light diffusion, 14 ... mirror reflection film,
16 ... refractive index adjusting film, 18 ... light absorbing film, 20 ... light absorbing film,
22 ... Front projector,
40a, 40b ... laptop or notebook personal computer,
42 ... personal computer main body,
44 ... front projection screen (display),
46 ... front projector, 50 ... terminal information device, 52 ... information terminal device body,
54 ... Front projection screen (display).

Claims (11)

A light diffusing layer that diffuses and transmits only light incident from a specific angle region and straightly transmits light incident from other angle regions;
A mirror-forming area having a predetermined inclination on the back side and a non-mirror-forming area having a predetermined inclination different from that are alternately arranged along a predetermined direction to form a surface that is bent in a sawtooth shape. Is a light transmissive layer bonded to the back side of the light diffusion layer on the opposite surface;
A specular reflection film made of a reflective material formed on the back surface of each of the mirror forming areas,
A screen for front projection using a one-side specular sawtooth-like reflector. A light diffusing layer that diffuses and transmits only light incident from a specific angle region and straightly transmits light incident from other angle regions;
A mirror-forming area having a predetermined inclination on the back side and a non-mirror-forming area having a predetermined inclination different from that are alternately arranged along a predetermined direction to form a surface that is bent in a sawtooth shape. Is a light transmissive layer bonded to the back side of the light diffusion layer on the opposite surface;
A specular reflection film made of a reflective material formed on the back surface of each of the mirror forming areas,
Have
A front projection screen using a one-side mirror-like serrated reflector, wherein the back surface of each mirror non-forming area is processed so as to have light diffusibility. A light diffusing layer that diffuses and transmits only light incident from a specific angle region and straightly transmits light incident from other angle regions;
A mirror-forming area having a predetermined inclination on the back side and a non-mirror-forming area having a predetermined inclination different from that are alternately arranged along a predetermined direction to form a surface that is bent in a sawtooth shape. Is a light transmissive layer bonded to the back side of the light diffusion layer on the opposite surface;
A specular reflection film made of a reflective material formed on the back surface of each of the mirror forming areas,
A refractive index adjusting film formed so as to cover each mirror reflection film of the light transmission layer and the back surface of each non-mirror forming area, and having a refractive index approximate to the light transmission film;
A screen for front projection using a one-side specular sawtooth-like reflector. The screen for front projection using the one-side specular sawtooth reflector according to claim 3, wherein a light absorption film is formed on a back surface of the refractive index adjusting film. A light diffusing layer that diffuses and transmits only light incident from a specific angle region and straightly transmits light incident from other angle regions;
A mirror-forming area having a predetermined inclination on the back side and a non-mirror-forming area having a predetermined inclination different from that are alternately arranged along a predetermined direction to form a surface that is bent in a sawtooth shape. Is a light transmissive layer bonded to the back side of the light diffusion layer on the opposite surface;
A specular reflection film made of a reflective material formed for each back surface of each mirror forming area on the back side of the light transmission layer;
A light-absorbing film formed on the back surface of each non-mirror forming area,
A screen for front projection using a one-side specular sawtooth-like reflector. A screen for front projection using the one-side specular serrated reflector according to claim 1;
A front projector that is arranged obliquely below the front of the front projection screen and projects image light to the front of the screen;
Have
The upper limit of the incident angle range of the image light of the front projector with respect to the light diffusion layer surface is θpt, the lower limit is θpb, and the upper limit of the diffusion angle region of the image light from the front projector diffused from the surface of the light diffusion layer is θdt When the lower limit is θdb,
−90 ° ≦ θpb ≦ θpt ≦ θdb ≦ θdt ≦ 90 °
A front projection type display device characterized by satisfying the above condition. A screen for front projection using the one-side specular serrated reflector according to claim 1;
A front projector that is arranged obliquely below the front of the front projection screen and projects image light to the front of the screen;
Have
The angle of the surface of each mirror non-forming area with respect to the normal line of the light diffusion layer is θ ₂ , and the angle of the light passing through the upper limit of the incident angle range of the image light projected from the front projector with respect to the normal line in the light transmission layer Is θpt ′,
θ ₂ > θpt′−20 °
A front projection type display device characterized by satisfying the above condition. A screen for front projection using the one-side specular serrated reflector according to claim 1;
A front projector that is arranged obliquely below the front of the front projection screen and projects image light to the front of the screen;
Have
The upper limit of the incident angle range of the image light of the front projector with respect to the light diffusion layer surface is θpt, the lower limit is θpb, and the upper limit of the diffusion angle region of the image light from the front projector diffused from the surface of the light diffusion layer is θdt When the lower limit is θdb,
−90 ° ≦ θpb ≦ θpt ≦ θdb ≦ θdt ≦ 90 °
While satisfying the conditions of
The angle of the surface of each mirror non-forming area with respect to the normal line of the light diffusion layer is θ ₂ , and the angle of the light passing through the upper limit of the incident angle range of the image light projected from the front projector with respect to the normal line in the light transmission layer Is θpt ′,
θ ₂ > θpt′−20 °
A front projection type display device characterized by satisfying the above conditions. A plurality of the front projectors are provided at different positions;
9. The front projection according to claim 6, 7 or 8, wherein a stereoscopic image is displayed on a front projection screen using the one-side specular serrated reflector by the image light of the plurality of front projectors. Type display device. A main body for information processing;
A display for displaying an image corresponding to the image signal generated by the main body;
A front projector that receives image signals from the main body and generates image light;
With
The display comprises a screen for front projection using the one-sided mirror-like sawtooth reflector described in any one of claims 1 to 5,
An information processing apparatus, wherein the front projector irradiates the image light toward a front projection screen using the one-side specular serrated reflector to display an image on the front projection screen. . The front projector is provided at a plurality of different positions,
11. The information processing apparatus according to claim 10, wherein a stereoscopic image is displayed on a front projection screen using the one-side specular serrated reflector by the image light of the plurality of front projectors.

Images