WO2006123727A1

WO2006123727A1 - Projection display screen using deflection element and projection display system

Info

Publication number: WO2006123727A1
Application number: PCT/JP2006/309899
Authority: WO
Inventors: Tatsuo Uchida; Baku Katagiri; Toru Kawakami; Yuhei Kuratomi
Original assignee: Tohoku Techno-Brains Corporation
Priority date: 2005-05-20
Filing date: 2006-05-18
Publication date: 2006-11-23
Also published as: TW200710536A; JP2006323284A

Abstract

A projection display screen using a deflecting element, hardly diffusion-reflecting extraneous light toward the viewer, and having a high contrast ratio at bright places and a projection system are provided. The screen comprises a deflecting element (1) for deflecting the entering light from a projector light entrance angle region and directing the light toward a deflecting element exit angle region and the deflecting element exit surface area corresponding to the projector light entrance angle region, a black matrix (BM) (2) having a transmitting surface area (2A) matching the deflecting element exit surface area, and a diffusion film (3) having an entrance allowable angle region matching the deflecting element exit angle region, diffusing the light entering from the deflecting element exit angle region , and directing the diffused light toward a viewing angle region corresponding to the deflecting element exit angle region. The three are lamination-arranged in order of mention to constitute the screen.

Description

Projection display screen and deflector using deflection element

Technical field

TECHNICAL FIELD [0001] The present invention relates to a projection display screen and a projection display system, and more particularly to a projection display screen and a projection using a deflection element that provide a display image with a high quality and a high contrast ratio.ヱ It relates to the cushion display system.

Background art

[0002] As the demand for projection displays increases, there is a demand for higher quality display images.

Therefore, the present inventors have realized a high quality display image by using a screen having a diffusion film force instead of a screen having a lenticular lens force used in a conventional projection display (for example, Patent Document 1). reference). Also, a thin rear projection display providing high image quality was realized by matching the allowable incidence angle area of the screen with the emission angle area of the projector light from the deflecting element (Patent Document 2).

Patent Document 1: PCT / JP03 / 13050

Patent Document 2: Japanese Patent Application No. 2004-190318

Disclosure of the invention

Problems to be solved by the invention

[0003] The inventors of the present invention have determined that it is essential to improve the photopic contrast ratio in order to achieve higher quality, and in order to realize this, diffuse reflection of external light to the viewer side is performed. The challenge was to control it. It is an object of the present invention to provide a projection display screen and a projection display system using a deflecting element, embodying a high-quality thin rear projection display that can solve this problem.

Means for solving the problem [0004] As a means for solving the above problems, the present inventors have used a thin rear projection display that provides the above-described high-quality image quality and is used in a screen composed of a conventional lenticular lens. By applying a matrix (abbreviation: BM), it is thought that it is possible to significantly suppress diffuse reflection of the external light to the observer side, and further investigations are described in the following claims. The present invention was made.

(Claim 1) A deflecting element that deflects incident light from a projector light incident angle region and emits the deflected light to a deflecting element exit angle region and a deflecting element exit surface region according to the projector light incident angle region, and A black matrix having a transmission surface area aligned with the deflection element exit surface area and an allowable incident angle area matched with the deflection element exit angle area are diffused to diffuse the incident light from the deflection element exit angle area. A projection display screen using a deflection element, in which a diffusion film that emits light in a viewing angle region corresponding to the element emission angle region is laminated in this order.

[0006] (Claim 2) A light absorbing member that covers all or part of the deflecting element other than the projector light incident part on the projector light incident side is disposed instead of or in combination with the black matrix. The screen according to claim 1.

(Claim 3) The screen according to claim 1 or 2, wherein the deflecting element is a prism array in which an upper surface and a lower surface of the prism form a single plane.

(Claim 4) The deflection element is a prism array in which either one or both of the upper surface and the lower surface of the prism are formed by joining a plurality of planes. Screen described.

(Claim 5) The screen according to claim 3 or 4, wherein the lower surface of the prism forms a single plane perpendicular to the incident direction of the projector light.

[0008] (Claim 6) The screen according to any one of claims 3 to 5, wherein the prisms of the prism array are spaced apart from each other.

(Claim 7) The screen according to claim 1, wherein the screen is condensed and deflected instead of being deflected.

(Claim 8) Instead of or in combination with the black matrix, light absorption that covers all or part of the deflecting element other than the projector light incident part on the projector light incident side 8. The screen according to claim 7, further comprising a member.

[0009] (Claim 9) The screen according to claim 7 or 8, wherein the deflecting element is a prism array in which one or both of an upper surface and a lower surface of the prism form a curved surface.

(Claim 10) The screen according to claim 9, wherein the lower surface of the prism forms a single plane perpendicular to the incident direction of the projector light.

(Claim 11) The screen according to claim 9 or 10, wherein the upper surface of the prism has a curved surface with a quadratic cross-sectional shape.

[0010] (Claim 12) The screen according to any one of claims 9 to L1, wherein the prisms of the prism array are spaced apart from each other.

(Claim 13) The screen according to any one of claims 1 to 12, wherein the black matrix has a thickness of 10 m or more.

(Claim 14) The refractive index of one or both of the deflection element and the diffusion film is matched with the refractive index of the medium satisfying the transmission surface area of the black matrix. Item 14. The screen according to any one of Items 1 to 13.

[0011] (Claim 15) The diffusion film includes a layered or linear structure having different refractive indexes, and emits incident light from a specific incident allowable angle region to a specific diffusion angle region. The screen according to claim 1, wherein the screen is provided.

(Claim 16) The screen according to any one of claims 1 to 15, wherein a polarizer or a circular polarizer is further disposed on the exit side surface of the diffusion film.

[0012] (Claim 17) A deflection having a projection optical system for combining the screen according to any one of claims 1 to 16 with projector light incident angle area force incident on the screen. Projection display system using elements.

The invention's effect

[0013] According to the present invention, it is possible to realize a high-quality thin rear projection display in which diffuse reflection of external light to the viewer side is suppressed and the photopic contrast ratio is high. Brief Description of Drawings

FIG. 1 is a schematic sectional view showing an example of a basic form of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of an embodiment of the present invention in which a BM and a light absorbing member are disposed together It is.

FIG. 3 is a schematic cross-sectional view showing an example of an embodiment of the present invention in which a prism surface is composed of a plurality of planes.

FIG. 4 is a schematic cross-sectional view showing an example of an embodiment of the present invention in which prisms are spaced apart from each other.

FIG. 5 is a schematic sectional view showing an example of an embodiment of the present invention using a deflecting element having a light condensing function.

FIG. 6 is a schematic cross-sectional view showing an example of an embodiment of the present invention in which the thickness of BM is relatively thick. Explanation of symbols

[0015] 1 Deflection element (eg prism array)

2 BM (Black matrix)

2A Transmission surface area

3 Diffusion film

4 Projector light

5 Outside light

6 Deflection element (Example: Prism array; condensing function)

7 Light absorbing member

BEST MODE FOR CARRYING OUT THE INVENTION

The basic form of the present invention is, for example, as shown in FIG. 1, a deflecting element 1 that changes the traveling direction of projector light 4, a BM (meaning black matrix; the same applies hereinafter) 2 that absorbs external light, and A diffusion film 3 for diffusing the projector light 4 is laminated in this order. The deflecting element 1 is an optical element having an optical characteristic that deflects incident light having a projector light incident angle region force and outputs the deflected light to a deflecting element exit angle region and a deflecting element exit surface region corresponding to the projector light incident angle region. For example, it consists of a prism array 1.

[0017] Deflection element 1 and BM2 that should avoid the projector light 4 being absorbed in BM2 are aligned with the transmission surface area 2A of deflection element exit surface area force ¾M2, and the deflection element exit surface area is BM2. Designed to be included in transparent area 2A. In addition, the deflection element 1 and the diffusion film 3 that slide so that all the projector light 4 is diffused to the observation angle region have a deflection element exit angle region. It is designed so that the area is aligned with the allowable incident angle area of the diffusing film 3 and the exit angle area of the deflecting element is included in the allowable incident angle area of the diffusing film 3.

[0018] According to the basic mode, the projector light 4 is not absorbed by the BM 2 and is diffused in the observation angle region, so that high projector light utilization efficiency can be realized. On the other hand, the external light 5 is incident on the screen from the observer side, reflected at the air interface of the prism array 1 and emitted to the observer side, and must pass through BM2 twice on the way. Is done. Therefore, a high external light suppression effect is realized.

[0019] The deflecting element 1 is not limited to the prism array illustrated in FIG. 1, but may be a lens array, a hologram, a mirror array, a fiber array, or the like having similar optical characteristics. A similar effect can be obtained.

In the present invention, instead of providing the BM, a light absorbing member may be provided to cover all or part of the deflecting element other than the projector light incident part on the projector light incident side. This also absorbs the external light incident on the screen, and similarly a high external light suppression effect can be obtained. Alternatively, for example, as shown in FIG. 2, it is possible to obtain a higher external light 5 suppressing effect by arranging the light absorbing member 7 together with BM2. In FIG. 2, the prism-shaped total reflection portion is covered with a light absorbing member. However, if there is a refractive index difference between the medium forming the prism and the light absorbing member, the total reflected light is not absorbed. Therefore, the prism-shaped total reflection portion can be covered with the light absorbing member, and a higher effect of suppressing external light 5 can be obtained.

[0020] When a prism array is used as the deflecting element, the upper surface of the prism is configured by joining a plurality of planes as shown in FIG. 3 (or the lower surface is similarly configured instead of or in addition to the upper surface). As a result, the cross-sectional area of the projector light 4 passing through the BM2 surface can be reduced, the transmission surface area 2A can be reduced, and a higher external light 5 suppression effect can be obtained.

Further, in the present invention, in addition to the basic form described above, a projector (not shown) is further arranged on the exit side surface (observer side surface) of the diffusion film 3 so that the projector light has linearly polarized light. Therefore, it is possible to absorb only 50% of outside light that is generally non-polarized light without lowering the projector light utilization efficiency, and to further increase the contrast ratio of the displayed image. Further In addition, by arranging a circular polarizer instead of the polarizer, when the projector light has circularly polarized light, in addition to the above effects, the backscattering in the diffusion film can be absorbed by the circular polarizer, and the display image It is possible to significantly increase the contrast ratio. In this case, in order to increase the use efficiency of the projector light, it is important that the polarization of the projector light is not broken by the deflection element. For this purpose, when the deflection element is a prism array, the incident surface of the prism It is desirable that the projector light is incident perpendicularly to the projector. For the same reason, in this case, it is desirable that the portion forming the transmission surface area of the BM (medium satisfying the transmission surface area) is matched in refractive index with the prism array and Z or the diffusion film.

[0021] When the deflecting element is a prism array, a plurality of prisms for deflecting the projector light need not be present on the entire projector light incident side, but as shown in FIG. By separating the individual prisms from each other, it is possible to suppress reflection of outside light 5 at unnecessary interfaces and obtain a higher effect of suppressing outside light.

By the way, in the basic form described above and the form in which a polarizer is added to this, a force projector that is designed so that all of the deflection element exit surface area is included in the BM transmission surface area is absorbed. In order to increase the external light suppression effect, it is also useful to make the BM transmission surface area small, so in the present invention, 80% or more of the BM is not limited to all of the deflection element exit surface area. The case where it is included in the transmission surface area of the light is allowed, and the case where it is covered is also included in the scope of the present invention. Similarly, it is not always necessary to cover all the area forces other than the deflection element exit surface area by the absorption surface area of ¾M. Only a part of the area other than the deflection element exit surface area is covered by the absorption area of force ¾M. Even if it is, it is possible to obtain an external light suppression effect.

[0022] In addition, since it is conceivable that an inevitable error occurs in the production of the deflection element emission angle area and the allowable incidence angle area of the diffusion film, the present invention is not limited to all of the deflection element emission angle areas. The case where 80% or more is included in the allowable incident angle region of the diffusing film is allowed, and the case where force is applied is also included in the scope of the present invention.

Fig. 1 shows an example in which the external light 5 incident on the transmission surface area 2A of BM2 is hardly absorbed in the transmission surface area 2A regardless of the incident angle, that is, the thickness of BM2 is almost infinitely small. It was. This example is a force that conforms to a commonly used form of BM. The present invention is not limited to this. For example, as shown in FIG. It may be the screen of the embodiment in which the minute is absorbed. In this type of screen, the transmission / absorption function of BM2 depends on both the surface area and the angle area, so that it is possible to further suppress the diffuse reflection of the external light 5 to the viewer side, which is preferable. In this embodiment as well, the above-mentioned condition that 80% or more of the deflection element exit surface area is included in the BM transmission surface area is satisfied, and thus the projector light utilization efficiency is the same as in FIG. Considering that the width of the conventional BM transmissive surface area (length in the vertical direction in the figure) is about 30 μm, in order to obtain an external light absorption function in a practical angular region, The thickness of the BM is preferably 10 m or more, more preferably 20 μm or more, further preferably 30 μm or more, and ideally 50 μm or more.

Next, FIG. 5 shows an example of the screen in FIG. 1 in which the deflecting element 6 having a condensing function is used instead of the deflecting element 1 having no condensing function. As shown in the figure, by condensing the projector light 4 on the BM2 surface by the deflecting element 6 having a condensing function, the transmission surface area 2A of the BM2 surface is reduced and the utilization efficiency of the projector light 4 is reduced. Therefore, it is possible to increase the external light 5 suppression effect.

In the example of FIG. 5, a prism array having a curved upper surface (total reflection surface) is used as the deflecting element 6 having a condensing function. Instead, the lower surface of the prism (projector) is used. (The surface on which the light 4 is incident) or a prism array with curved upper and lower surfaces may be used, or a lens array, hologram, mirror array, fiber array, etc. may be used instead of the prism. Obtainable.

[0025] Regarding the case where the deflecting element is a prism array, assuming that the individual prisms are sufficiently fine, the assumption that the incident angle of the projector light does not change within one prism holds. By using a quadratic curved surface as the curved surface, the projector light can be focused on one point on the BM surface. As a result, the BM absorption surface area can theoretically be set to approximately 100%. Therefore, when using a prism array in which only the upper surface of the prism is curved and the lower surface is flat as shown in FIG. It is desirable that the curve on the upper surface of the prism is such that the cross-sectional shape of the curved surface is a quadratic curve. [0026] When a polarizer or a circular polarizer is arranged on the surface on the viewer side of the screen using the deflecting element 6 having a condensing function, and a BM having a transmission 'absorption function depending not only on the surface area but also on the angle area When the light absorbing member is disposed instead of or in addition to BM, and when the deflecting element 6 having the light condensing function is a prism array in which the prisms are spaced apart from each other, In the case of the deflecting element 1 having no function, the same argument as described above holds.

[0027] Also, in the case of the deflecting element 1 having no condensing function, the matching between the deflecting element exit surface area and the BM transmitting surface area and the consistency between the deflecting element exit angle area and the allowable incident angle area of the diffusion film The same argument holds as described above.

Here, the external light passes through the BM twice, and the absorption factor of the BM works as a square. Therefore, the increase of the external light suppression effect by collecting the projector light is very large. Therefore, with the deflection element 6 having a light condensing function, the ratio of the transmission surface area on the BM surface is not limited to an ideal shape in which the projector light is focused on one point on the BM surface. If it is 80% or less compared to the configuration using the deflecting element 1 having no light condensing function, this is allowed, and such a case is also included in the scope of the present invention.

[0028] However, if the transmission surface area of the BM is too small, the diffusion film force may also be such that the area from which the projector light is emitted becomes too small and the image may become discontinuous. By using the divergence of the light after condensing and arranging the BM and the diffusion film apart from each other, it is possible to avoid projecting the projector light into the diffusion film without making the discontinuity of the image inconspicuous. it can.

[0029] In order to make the above argument valid, the positional relationship between the projector and the screen, and the projector light emission angle of the projector power are strictly adjusted to obtain the matching as the projection system. It is important to make light incident.

Here, since the projector light incident angle region varies depending on the location of the screen, it is desirable that the deflection characteristics of the deflecting element differ depending on the location of the screen. As long as this holds, a part of the external light is absorbed by the BM, so that the contrast ratio can be increased. [0030] In addition, the force shown in the cross-sectional view of the screen in FIGS. 1 to 6 As long as the above-described conditions are satisfied, a part of the external light is absorbed in the BM, so the structure in the direction perpendicular to the paper in the figure is not particularly limited . Specifically, for example, when a prism array is used, the three-dimensional shape of the prism array is a Fresnel lens type prism array shape that can be obtained by rotating the screen cross-sectional figures of FIGS. 1 to 6 around one central axis perpendicular to the screen surface. However, as long as the above conditions are satisfied, for example, the prism array shape in which the cross-sectional shapes at all the positions in the vertical direction of FIGS. In addition, the effect of suppressing external light can be realized.

[0031] In order to manufacture the screen of the present invention, as a BM material and a light-absorbing member material, a material that is decomposed by photosensitivity and that peels only the decomposed portion by subsequent cleaning is used. The light absorbing member material, the deflecting element, the BM material, and the diffusing film are laminated in this order, or the light absorbing member material, the deflecting element, and the diffusing film are stacked in this order, and the deflecting element is incident on this. It is preferable to use a manufacturing method in which projector light is incident from the side.

[0032] According to the above manufacturing method, the projector light incident on the deflecting element exits to the deflecting element exit area corresponding to the projector light incident angle area according to the deflection characteristics of the deflecting element, and the BM material and Z or the light absorbing member material Is exposed to light, so that the exposed portion becomes the transmission surface area as it is. That is, according to this manufacturing method, the transmission surface area of the BM (in the case of a light absorbing member, the portion not covered by this corresponds to the transmission surface area) is automatically adjusted to the deflection element emission surface area. Can do. As described above, the deflecting element can be formed of a lens array, a hologram, a mirror array, a fiber array, or the like in addition to the prism array. Diffusion films are commonly used in the past, and include diffusion films that use diffusion due to internal fine particles, diffusion films that use diffusion due to surface roughness, hologram diffusion films, etc. A diffusion film that includes an angle region and a diffusion angle region matched with the angle region and includes a layered or linear structure having different refractive indexes and emits incident light from a specific incident allowable angle region to a specific diffusion angle region. It can be preferably used. Example

In the embodiment, the prism array is used in the case where the prism array is used as the deflecting element. The projector incident angle with respect to the BM was set to 55 ° to 75 °, and the ratio of the BM absorption area in the BM plane was derived by numerical simulation. Here, the allowable incidence angle region of the diffusion film was set to −25 to 25 °. The angle is 0 ° for the direction normal to the prism alignment direction of the prism array (the normal of the surface where the prisms are aligned), and the counterclockwise direction is positive.

In the optical system shown in Fig. 1, the angle of inclination of the upper and lower surfaces of the prism is 36 ° and -9 °, respectively, so that projector light with a projector light incident angle of 55 to 75 ° can be incident on the diffusion film without loss. It is possible to deflect in the angular region. When the projector light incident angle is 55 ° and 75 °, the ratio of the absorption surface area of BM is 38% and 74%, respectively.

On the other hand, in the optical system shown in FIG. 5, if the prism bottom surface is perpendicular to the projector light incident direction and the prism top surface is curved to a quadratic curve, the projector light is incident when the projector light incident angle is 55 °. Is incident on the top surface of the prism at an angle between 54.32 ° and 70.68 °. In addition, when the projector light incident angle is 75 °, the projector light is incident on the upper surface of the prism at an angle of 44.32 ° to 60.68 °. Since this prism array is made of a material that totally reflects if the incident angle at the air interface is 41 ° or more, the projector light is totally reflected on the top surface of the prism, and the projector light is lost without loss. Can be deflected to an allowable angle range of incident light, and it is theoretically possible to absorb almost 100% of external light.

Claims

The scope of the claims

[1] A deflecting element that deflects incident light from a projector light incident angle region and emits the deflected light to a deflecting element exit angle region and a deflecting element exit surface region according to the projector light incident angle region, and the deflecting element exit surface region And a black matrix having a transmission surface area matched to the deflection element, and an incident allowable angle area matched to the deflection element emission angle area, and diffusing incident light from the deflection element emission angle area to the deflection element emission angle area. A projection display screen using a deflecting element, which is formed by laminating and arranging a diffusion film that emits light in the corresponding observation angle region.

[2] A light absorbing member that covers all or part of the deflection element other than the projector light incident portion on the projector light incident side is disposed instead of or in combination with the black matrix. Item 1. A screen according to item 1.

3. The screen according to claim 1, wherein the deflection element is a prism array in which an upper surface and a lower surface of the prism form a single plane.

[4] The deflecting element is a prism array in which either one or both of an upper surface and a lower surface of a prism are formed by joining a plurality of planes.

2. The screen according to 2.

5. The screen according to claim 3 or 4, wherein the lower surface of the prism forms a single plane perpendicular to the incident direction of the projector light.

6. The screen according to any one of claims 3 to 5, wherein the prisms of the prism array are spaced apart from each other.

7. The screen according to claim 1, wherein the screen is condensed and deflected instead of being deflected.

[8] A light absorbing member that covers all or part of the deflecting element other than the projector light incident portion on the projector light incident side is disposed instead of or in combination with the black matrix. Item 7. The screen according to item 7.

9. The screen according to claim 7, wherein the deflection element is a prism array in which either one or both of the upper surface and the lower surface of the prism form a curved surface.

[10] The lower surface of the prism forms a single plane perpendicular to the incident direction of the projector light. The scukuleen as described in claim 99. .

[11] The upper surface of the above-mentioned pre-rismum is characterized by a curved surface in which the cross-sectional surface shape is a 22nd-order curved linear shape. Skeleton as described in claim 99 or 1100. .

[12] Claims 99 to 99 characterized in that the above-mentioned pre-listism of the above-mentioned pre-listism of the above-mentioned pre-listism is arranged at a distance from each other. ~ 11 11 Skukurien as described in any one of 11-11. .

[13] The claim according to claim 11 characterized in that the thickness of the black bear trimmer is above 1100 mm. ~ Skulleneen described in any one of ~ 1122. .

[14] In contrast to the refractive index ratio of the medium medium that fully fills the transmission / transmission surface area of the above-mentioned Brackack Kumamatotrix, The refractive index of one or both of the directional elements and the above-mentioned diffuse diffusion film is adjusted. Claim Skeleton as described in any one of Claims 11 to 1133, which is characterized as a special feature. .

[15] The above-mentioned diffuse diffusion film includes a layered structure or a linear structure in which the refractive index is different from each other. The incident incident light from the specific incident allowable angle of incidence angle range area is emitted to the specific diffusion angle angle range area. A script as described in any one of claims 11 to 1144, characterized in that it is a feature of the diffusion and diffusion film that is to be diffused. Lean. .

[16] Furthermore, polarized light photons or circularly polarized light photons are arranged on the surface of the outgoing and outgoing radiation side of the above-mentioned diffuse diffusion film. Claims described in any one of claims 11 to 1155. .

[17] Combining the scukurinen described in any one of claims 11 to 1166 in combination with the sccrily Projection projection optics system that makes incident light incident on incident light incident angle angle range of light incident on the projector Have a system *