CN112513685B - Reflecting screen and image display system - Google Patents

Abstract

The invention reduces the reflection of external light and improves the contrast. The reflection screen (20) is a reflection screen capable of reflecting image light formed by red, green and blue laser beams projected from an image source LS and capable of being observed, and is characterized by comprising: the optical element comprises a base layer (24), a lens layer (23) formed in a Fresnel lens shape on the back surface side, which is the opposite side of the base layer (24) from the image source side, and a reflection layer (22) provided on the back surface side of the lens layer (23), wherein a light absorbing section having wavelength selectivity is provided on the image source side of the reflection layer (22).

Description

Reflecting screen and image display system

Technical Field

The present invention relates to a reflective screen and an image display system for reflecting irradiated image light to display an image.

Background

Conventionally, an image display system has been proposed in which various images are displayed by irradiating an image light onto a reflective screen.

Regarding a reflective screen applied to such an image display system, patent documents 1 to 3 propose a reflective screen that reduces reflection of external light and improves contrast by providing a light absorbing layer.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 6-75304

Patent document 2: japanese patent laid-open No. 9-133969

Patent document 3: japanese patent laid-open No. 2008-170607

Disclosure of Invention

Problems to be solved by the invention

However, in such an image display system, it is desired to further reduce reflection of external light and improve contrast.

The present invention has been made in view of the above circumstances, and provides a reflective screen and an image display system capable of reducing reflection of external light and improving contrast.

Means for solving the problems

The present invention solves the above problems by the following means. For ease of understanding, the symbols corresponding to the embodiments of the present invention are given for explanation, but the present invention is not limited thereto.

The 1 st invention relates to a reflection panel (10, 120, 220, 320, 420, 520) capable of reflecting image light formed by red, green, and blue laser light projected from an image source (LS) and observing, comprising: the optical element comprises a base layer (24, 524), a lens layer (23) formed in a Fresnel lens shape on the back side of the base layer opposite to the image source side, and a reflection layer (22, 522) provided on the back side of the lens layer, wherein a light absorbing section having wavelength selectivity is provided on the image source side of the reflection layer.

The invention 2 relates to the reflection screen (10) according to the invention 1, wherein the light absorbing portion is formed of the base material layer (24, 242) containing a material having wavelength selectivity.

The 3 rd invention relates to the reflection screen (120) according to the 1 st invention, wherein the light absorbing portion is formed of the lens layer (123) containing a material having wavelength selectivity.

The 4 th invention relates to the reflecting screen (10, 120) according to the 1 st invention, wherein the light absorbing portion contains two or more kinds of wavelength selective materials (a to D) having light absorption bands in a wavelength band not including wavelengths of the laser light of red, green, and blue.

The invention 5 relates to the reflective screen (220, 320, 420) according to claim 1, wherein the light absorbing portion is a light absorbing layer (225, 326, 426) which contains a material having wavelength selectivity and is provided on the image source side of the reflective layer (22).

The 6 th aspect of the present invention relates to the reflecting screen (220, 320, 420) according to the 5 th aspect of the present invention, wherein the light absorbing layer (225, 326, 426) contains two or more kinds of wavelength-selective materials (a to D) having light absorption bands in a wavelength band excluding the wavelengths of the red, green, and blue lasers.

The invention 7 relates to the reflection screen (320) according to the invention 6, wherein two or more absorption layers (326 a to 326D) containing materials (a to D) having different wavelength selectivities are laminated in the light absorption layer (326).

The 8 th aspect of the present invention relates to the reflection screen (420) according to the 5 th aspect of the present invention, wherein the light absorbing layer (426) is patterned so as to selectively transmit a red region (R) of the image light formed by the red laser light, a green region (G) of the image light formed by the green laser light, and a blue region (B) of the image light formed by the blue laser light.

The invention 9 relates to the reflecting screen (520) according to the invention 1, wherein the reflecting screen has a maximum value of reflectance in a region of ±50nm centered on the wavelength of the laser light of red, green, and blue when the spectral reflectance of the reflecting screen is measured.

The 10 th aspect of the present invention relates to the reflection panel (520) according to the 9 th aspect of the present invention, wherein the light absorbing portion (242) satisfies the relation PA/PB not less than 1.16 when the average value of the reflectances at the wavelengths of the red, green and blue lasers is PA, the average value of the reflectances at the wavelengths of the light in the visible light range is PB, and the ratio thereof is PA/PB.

The 11 th invention relates to the reflecting screen (520) according to the 10 th invention, wherein a color difference ΔE between chromaticity of black display and chromaticity of achromatic color as a reference ^* ab satisfies ΔE ^* ab≤2.4。

The 12 th aspect of the present invention relates to an image display system (1), comprising: the reflection screen (10) of claim 1, and an image source (LS) for irradiating the reflection screen with image light.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, reflection of external light can be reduced and contrast of an image can be improved.

Drawings

Fig. 1 is a diagram illustrating an image display system according to embodiment 1.

Fig. 2 is a diagram illustrating the layer structure of the reflective screen according to embodiment 1.

Fig. 3 is a diagram illustrating details of the lens layer and the reflection layer of embodiment 1.

Fig. 4 is a characteristic diagram showing optical characteristics of a material having wavelength selectivity contained in the light absorbing portion.

Fig. 5 is a diagram illustrating the layer structure of the reflective screen according to embodiment 2.

Fig. 6 is a diagram illustrating the layer structure of the reflection screen according to embodiment 3.

Fig. 7 is a diagram illustrating the layer structure of the reflection screen according to embodiment 4.

Fig. 8 is a diagram illustrating the layer structure of the reflection screen according to embodiment 5.

Fig. 9 is a partial enlarged view of the light absorbing layer of embodiment 5 as seen from the observer side.

Fig. 10 is a view showing another embodiment of the light absorbing layer of embodiment 5.

Fig. 11 is a diagram illustrating the layer structure of the reflection screen 520 according to embodiment 6.

Fig. 12 is a diagram illustrating a surface layer 525.

Fig. 13 is a graph showing measurement results of spectral reflectances of the reflection panels of measurement examples 1 to 4.

Fig. 14 is a graph showing measurement results of spectral reflectances at points a of the reflection panels of measurement examples 1 to 5.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

The drawings shown below, including fig. 1, are schematically represented, and the dimensions and shapes of the respective parts are appropriately exaggerated for easy understanding.

In the present specification, terms such as a plate and a sheet are used, and as a general usage, a plate, a sheet, and a film are used in this order from a thick to a thin, and the present specification also uses the terms as an approximation. However, such distinction is not technically meant, and thus these words may be appropriately substituted.

Numerical values such as dimensions and material names of the respective members described in the present specification are examples of embodiments, and are not limited thereto, and may be appropriately selected and used.

In the present specification, terms defining shapes and geometric conditions, such as parallel terms and orthogonal terms, include a state where the same optical function is exhibited and errors are present in the degree that the terms can be regarded as parallel or orthogonal terms, in addition to strict meanings.

[ embodiment 1 ]

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a diagram illustrating an image display system 1 according to the present embodiment. Fig. 1 (a) is a perspective view of the image display system 1, and fig. 1 (b) is a perspective view of the image display system 1.

As shown in fig. 1, the image display system 1 includes a reflection screen unit 10 including a reflection screen 20, an image source LS, and the like. The image display system 1 of the present embodiment emits image light L from the image source LS toward the reflection panel 20, and reflects the image light L by the reflection panel 20, thereby displaying a desired image.

The image display system 1 can be used, for example, as a front projection television system in which an image source LS is provided on the viewer O side of the reflection screen 20.

The image source LS is an image light projecting device that projects image light L onto the reflecting screen 20. In the use state, when the screen of the reflective screen 20 is viewed from the normal direction (the normal direction of the screen surface), the video source LS is disposed at the center in the left-right direction of the screen of the reflective screen 20 and at a position below the screen (display area) of the reflective screen 20.

The image source LS projects image light L from a position (for example, a distance from the image source LS to the reflecting screen 20 is about 300 mm) which is substantially closer to the reflecting screen 20 in a direction perpendicular to the screen of the reflecting screen 20 (thickness direction of the reflecting screen 20) than a conventional general-purpose projector and a general-purpose short-focal projector. That is, the projection distance of the image source LS to the reflecting screen 20 is shorter than that of the conventional general-purpose projector and short-focus projector, and the incident angle of the image light L to the screen surface of the reflecting screen 20 is also large.

In the case of using a general-purpose projector or a short-focus projector as an image source as in the prior art, the distance between the image source and the reflective screen needs to be set to be 1m to several m or more, and thus a person may cross between the reflective screen and the image source to block the display of an image. In addition, in order to provide the image source and the reflection screen at such arrangement intervals, a sufficiently large room is required.

In contrast, in the image display system 1 of the present embodiment, since the image source LS uses the ultra-short focal projector as described above, the distance between the image source LS and the reflective screen 20 can be significantly shortened as described above, and the above-described problems can be solved.

The image source LS of the present embodiment uses red, green, and blue laser sources, and emits image light L formed by red, green, and blue lasers.

The reflection screen 20 reflects the image light L irradiated from the image source LS toward the observer O side, and displays an image. In the use state, the observation screen of the reflecting screen 20 is approximately rectangular with the longitudinal direction being the screen left-right direction, as viewed from the observer O side.

In the following description, unless otherwise specified, the screen up-down direction, the screen left-right direction, and the thickness direction refer to the screen up-down direction (vertical direction), the screen left-right direction (horizontal direction), and the thickness direction (depth direction) in the use state of the reflecting screen 20.

The reflection screen 20 has a large screen (display area) of, for example, 100 inches and 120 inches on a diagonal.

The image display system 1 of the present embodiment includes the image source LS of the ultra-short focal projector and the reflective screen 20 that reflects the image light irradiated from the image source LS to display an image, but the image source LS is not limited to this, and may be a conventional general-purpose projector or a short focal projector that has a longer irradiation distance and a smaller irradiation angle of the image light (that is, an incident angle of the image light to the screen) than the ultra-short focal projector, and the reflective screen 20 may be set to a reflective screen corresponding to such an image source LS.

As shown in fig. 1, the reflecting screen unit 10 includes a reflecting screen 20, a flat plate-shaped supporting plate 30 disposed on the back surface side thereof, and a bonding layer 40. The reflection screen 20 is integrally bonded to the support plate 30 through the bonding layer 40.

The material of the support plate 30 is not particularly limited as long as it has high rigidity, and for example, a metal plate such as aluminum, a resin plate such as an acrylic resin, or the like is preferably used. Further, a metal plate (so-called honeycomb plate) or the like having a honeycomb structure formed by a thin plate such as aluminum on the front and back surfaces and a thin plate such as aluminum as the inner core material can be used, whereby the weight of the entire plate can be reduced. In addition, from the viewpoint of preventing reflection of external light, reduction of contrast due to external light, or the like, the support plate 30 is preferably a member having no light transmittance.

The thickness of the support plate 30 is preferably 0.2 to 5.0mm, more preferably 1.0 to 3.0mm. When the thickness is less than 0.2mm, rigidity enough to support flatness is not imparted, and when it is more than 5.0mm, the weight of the support plate 30 becomes heavy.

The reflective screen 20 is thin, and often does not have sufficient rigidity to maintain flatness when used alone. Therefore, the reflection screen 20 is integrally joined to the support plate 30, thereby maintaining the flatness of the screen.

The joining layer 40 is a layer having a function of joining the reflecting screen 20 and the supporting plate 30 as a whole. The bonding layer 40 is formed of an adhesive or an adhesive agent, or the like.

Fig. 2 is a diagram illustrating the layer configuration of the reflection screen 20 according to the present embodiment.

In fig. 2, a part of a cross section passing through a point a, which is the geometric center (screen center) of an observation screen (display area) of the reflection screen 20 (see fig. 1 (a), (b)), parallel to the screen up-down direction, and perpendicular to the screen surface (parallel to the thickness direction) is shown enlarged.

As shown in fig. 2, the reflection screen 20 includes a surface layer 25, a base material layer 24, a lens layer 23, and a reflection layer 22 in this order from the image source side (viewer side) in the thickness direction.

The base material layer 24 is a sheet-like member as a base material for forming the lens layer 23. A surface layer 25 is integrally formed on the image source side of the base layer 24, and a lens layer 23 is integrally formed on the back side (back side).

The base material layer 24 has a light diffusion layer 241 containing a diffusing agent and a coloring layer 242 absorbing light of a specific wavelength. The base material layer 24 of the present embodiment is formed by co-extrusion molding the light diffusion layer 241 and the colored layer 242, and thus is integrally laminated.

In the present embodiment, as shown in fig. 2, in the base material layer 24, the light diffusion layer 241 is on the back surface side, and the coloring layer 242 is on the image source side, that is, the light diffusion layer 241 and the coloring layer 242 are laminated in this order on the image source side surface of the lens layer 23.

The light diffusion layer 241 is a layer containing a light-diffusing agent that diffuses light and uses a light-transmitting resin as a base material. The light diffusion layer 241 has a function of expanding a viewing angle and improving in-plane uniformity of brightness.

As the resin of the base material of the light diffusion layer 241, for example, PET (polyethylene terephthalate) resin, PC (polycarbonate) resin, MS (methyl methacrylate-styrene) resin, MBS (methyl methacrylate-butadiene-styrene) resin, TAC (cellulose triacetate) resin, PEN (polyethylene naphthalate) resin, acrylic resin, or the like is preferably used.

As the diffusing agent contained in the light diffusion layer 241, particles made of a resin such as an acrylic resin, an epoxy resin, or a silicon resin, or inorganic particles are preferably used. The diffusing agent may be a combination of an inorganic diffusing agent and an organic diffusing agent. The diffusing agent is preferably approximately spherical, and has an average particle diameter of about 1 μm to 50. Mu.m. The particle size of the diffusing agent suitable for use is preferably in the range of 5 to 30. Mu.m.

The thickness of the light diffusion layer 241 also depends on the screen size of the reflection screen 20, etc., but is preferably about 100 μm to 2000 μm. The haze value of the light diffusion layer 241 is preferably in the range of 85 to 99%.

The colored layer 242 is a light absorbing portion that transmits light in a specific wavelength band among the incident light and absorbs other light. More specifically, the coloring layer 242 absorbs almost no red, green, and blue laser light irradiated from the image source LS and selectively transmits the same, but absorbs light (mainly visible light) in other wavelength bands. Therefore, the coloring layer 242 hardly absorbs the image light irradiated from the image source, but can absorb unnecessary light such as external light, and can improve the contrast of the image.

As the resin of the base material of the colored layer 242, PET resin, PC resin, MS resin, MBS resin, TAC resin, PEN resin, acrylic resin, or the like can be used.

As the light absorber contained in the base material of the colored layer (light absorbing portion) 242, a material having wavelength selectivity is used, and for example, a dye including an azo structure, a phthalocyanine structure, a quinacridone structure, an anthraquinone structure, an indoline structure, an indanthrone structure, a perylene structure, a porphyrin structure, a squaraine salt structure, a thiophene structure, or the like can be used.

In this embodiment, the colored layer (light absorbing portion) 242 is formed by mixing two or more kinds of wavelength-selective materials (light absorbers) having light absorption bands in wavelength bands not including wavelengths of red, green, and blue lasers related to the image light L in the base material.

Fig. 4 is a characteristic diagram showing optical characteristics of a material having wavelength selectivity contained in the light absorbing portion (colored layer 242). Fig. 4 (a) to (D) are graphs showing the optical characteristics of the materials a to D having wavelength selectivity contained in the light absorbing portion, respectively, wherein the vertical axis represents the light absorptance [% ], and the horizontal axis represents the light wavelength [ nm ].

The colored layer (light absorbing portion) 242 of the present embodiment contains materials a to D shown in each of fig. 4 (a) to (D) in a resin material as a base material.

As shown in fig. 4 a, the material a is a dye having a light absorption band on the short wavelength side of the blue laser beam LB (wavelength 465 nm). The light absorption characteristic peak of the material A has a wavelength of 402nm and the half-width of the light absorption rate is 10-80 nm. Here, the half-width of the light absorptance means a difference between a value of a wavelength on a short wavelength side and a value of a wavelength on a long wavelength side which reach a half value of the absorption peak.

The material a is not limited to the above examples, and a dye having a light absorption band and a light absorption characteristic peak in a wavelength region on a short wavelength side of the wavelength of the blue laser beam LB may be used, and for example, an azomethine compound, an indole compound, a cinnamic acid compound, a porphyrin compound, or the like may be used, and a pyrimidine compound (the peak wavelength of the light absorptance is 394 nm) is preferable. As the material a, they may be used in combination as appropriate.

As shown in fig. 4B, the material B is a dye having a light absorption band on the long wavelength side of the red laser light LR1 (wavelength 638 nm). The light absorption characteristic peak of the material B has a wavelength of 680nm and the half-width of the light absorption rate is 10-80 nm. In addition, laser LR2 having a wavelength of 642nm may be applied to red laser light.

The material B is not limited to the above example, and a dye having a light absorption band and a light absorption characteristic peak in a wavelength region on the longer wavelength side than the wavelengths of the red lasers LR1 and LR2 may be used. The material B is preferably a phthalocyanine compound (peak wavelength of light absorptance: 680 nm), for example.

As shown in fig. 4 (C), the material C is a dye having a light absorption band between the wavelengths of the green laser light LG (wavelength 525 nm), the red laser light LR1 (wavelength 638 nm), and the wavelengths of these laser light LG and LR 1. The light absorption characteristic peak of the material C has a wavelength of 594nm and a half-width of the light absorption rate of 10 to 70nm.

The material C is not limited to the above example, and a dye having a light absorption band and a light absorption characteristic peak in a wavelength region around 590nm (570 to 620 nm) between the wavelength of the green laser light LG and the wavelength of the red laser light LR1 on the short wavelength side of the red laser light may be used, and for example, a cyanine compound, a diphenyl squarylium salt processed product, or the like, preferably a porphyrin compound (the peak wavelength of light absorptance is 585 nm) may be used. As the material C, they may be used in combination as appropriate.

As shown in fig. 4D, the material D is a dye having a light absorption band between the wavelengths of the green laser light LG (wavelength 525 nm) and the blue laser light LB (wavelength 465 nm). The light absorption characteristic peak of the material D has a wavelength of 493nm and a half-width of light absorption rate of 10-80 nm.

The material D is not limited to the above examples, and a dye having a light absorption band and a light absorption characteristic peak in a wavelength region around 490nm (480 to 510 nm) between the wavelength of the blue laser beam LB and the wavelength of the green laser beam LG may be used, and for example, a pyrazole-based squarylium compound, a dipyrromethene compound, or the like, preferably a merocyanine compound (the peak wavelength of the light absorption rate is 496 nm) may be used. As the material D, they may be used in combination as appropriate.

By mixing the materials (a to D) having the light absorption bands in the wavelength bands excluding the wavelengths of the red, green, and blue lasers related to the image light L, the colored layer 242 can be formed so as to selectively transmit the red, green, and blue lasers related to the image light L.

Fig. 3 is a diagram illustrating details of the lens layer 23 and the reflection layer 22 of the present embodiment.

Fig. 3 (a) shows a case where the lens layer 23 is viewed from the front side on the back side, and the reflecting layer 22 is omitted for ease of understanding. Fig. 3 (b) shows a part of the cross section shown in fig. 2 in further enlarged form. Fig. 3 (c) shows an enlarged perspective view of the lens layer formed with the reflection layer. In fig. 3 (b) and 3 (c), the illustration of the base material layer 24 and the surface layer 25 on the image source side of the lens layer 23 is omitted for ease of understanding.

The lens layer 23 is a layer having light transmittance provided on the back surface side of the base material layer 24, and has a circular fresnel lens shape in which a plurality of unit lenses 231 are arranged concentrically with respect to the point C on the back surface side thereof as shown in fig. 3 (a) and the like. In this circular fresnel lens shape, a point C, which is an optical center (fresnel center) thereof, is located on the lower side of the reflective screen 20 outside the area of the screen (display area) of the reflective screen 20.

In the present embodiment, the lens layer 23 has a circular fresnel lens shape on the back surface side, but the present invention is not limited to this, and the unit lenses 231 may have linear fresnel lens shapes arranged in the screen up-down direction or the like along the screen surface.

As shown in fig. 2 and 3 b, the unit lenses 231 have a cross-sectional shape that is approximately triangular in a cross-section parallel to a direction orthogonal to the screen surface (thickness direction of the reflective screen 20) and parallel to the arrangement direction of the unit lenses 231.

The unit lens 231 protrudes toward the rear surface side, and includes a lens surface 232 and a non-lens surface 233 facing the lens surface 232.

In the present embodiment, in the use state of the reflecting screen 20, the lens surface 232 of the unit lens 231 is positioned above the non-lens surface 233 in the vertical direction with the vertex t interposed therebetween.

As shown in fig. 3 (b), the angle formed by the lens surface 232 of the unit lens 231 and the surface parallel to the screen surface is α. In addition, the angle between the non-lens surface 233 and the surface parallel to the screen surface is β (β > α). The arrangement pitch of the unit lenses 231 is P, and the lens height of the unit lenses 231 (the dimension from the vertex t in the thickness direction of the screen to the point v which is the valley between the unit lenses 231) is h.

For easy understanding, in fig. 2 and the like, the arrangement pitch P, the angles α, β of the unit lenses 231 are shown to be constant in the arrangement direction of the unit lenses 231. However, in practice, although the arrangement pitch P or the like of the unit lenses 231 of the present embodiment is constant, the angle α gradually increases as it moves away from the point C, which is the fresnel center, in the arrangement direction of the unit lenses 231. In addition, the lens height h also varies. In the unit lenses 231 of the present embodiment, the arrangement pitch P is formed in a range of 50 to 200 μm, the lens height h is formed in a range of 0.5 to 60 μm, the angle α of the lens surface 232 is formed in a range of 0.5 to 35 °, and the angle β of the non-lens surface 233 is formed in a range of 45 to 90 °.

The arrangement pitch P may be changed gradually along the arrangement direction of the unit lenses 231, and may be changed as appropriate according to the size of the pixels (pixels) of the image source LS that projects the image light L, the projection angle of the image source LS (the angle of incidence of the image light on the screen surface of the reflective screen 20), the screen size of the reflective screen 20, the refractive index of each layer, and the like.

The lens layer 23 is formed of an ultraviolet curable resin such as urethane acrylate or epoxy acrylate on the back surface side of the base material layer 24. The lens layer 23 may be formed of another ionizing radiation curable resin such as an electron beam curable resin.

The lens layer 23 may be formed by a press molding method or the like according to the fresnel lens shape of the lens layer 23. In addition, a support layer may be provided as a base material of the lens layer 23, and the lens layer 23 may be formed on the back surface side of the support layer by the above-described method or the like. In the case of such a lens layer 23, the base material layer 24 and the like may be laminated on the image source side thereof by a bonding layer and the like not shown.

The reflective layer 22 is a layer having a function of reflecting light. The reflective layer 22 has a thickness sufficient to reflect light, and is formed on at least a portion of the lens surface 232 of the unit lens 231.

As shown in fig. 2 and 3 (b), the reflective layer 22 of the present embodiment is formed on the lens surface 232 and the non-lens surface 233. Specifically, the reflective layer 22 is formed so as to cover the back surface side of the lens layer 23 and to fill the boundary between the unit lenses 231 protruding toward the back surface side, that is, the point v which becomes the valley bottom. Thus, the reflective layer 22 can make the irregularities on the back surface side of the lens layer substantially flat, and the support plate 30 can be attached more stably by the bonding layer 40.

Here, as described above, the lens height h of the unit lenses 231 varies with distance from the point C, which is the fresnel center, in the arrangement direction of the unit lenses 231, but in order to more effectively exert the above-described effect, it is preferable that the thickness of the reflection layer 22 in the thickness direction of the lens layer 23 at the point v, which is the valley bottom between the unit lenses 231, is formed in a size in the range of 10 to 120% relative to the lens height h of each unit lens 231.

The reflection layer 22 is formed on the lens surface 232 by spraying a paint (resin) containing a scaly metal thin film 22a having high light reflectivity such as aluminum on the lens surface 232. The reflection layer 22 is disposed so that a surface perpendicular to the thickness direction of the metal thin film 22a is substantially parallel to the lens surface 232, and can appropriately reflect the image light L incident on the lens surface 232 toward the viewer. Here, the substantially parallel includes not only the case where the surface perpendicular to the thickness direction of the metal thin film 22a is completely parallel to the lens surface 232, but also the case where the slope with respect to the lens surface 232 is in the range of-10 ° to +10°. The scale-like metal thin film 22a is a scale-like shape (external shape) as viewed from the thickness direction of the metal thin film 22a, and includes not only a scale-like shape but also an elliptical shape, a circular shape, a polygonal shape, an irregular shape obtained by pulverizing a thin film, and the like.

Here, the characteristics of the scaly metal thin film are classified into a floating type, a non-floating type, a resin coating type, and the like, and the resin coating type is preferable in view of the adhesion, the orientation, and the like, although the metallic luster is important as the present embodiment, since the metallic luster is also important.

In order to maintain and improve the reflection efficiency of the image light and prevent the image light from being transmitted to the back surface side of the reflective layer 22, the metal thin film 22a is preferably laminated on the lens surfaces of a plurality of unit lenses existing on average by 8 layers or more. The reflection layer 22 provided with 8 or more layers of the metal thin film 22a may be provided on a part of the lens surfaces 232 of the plurality of unit lenses 231, or may be provided on all of the lens surfaces 232.

The coating material forming the reflective layer 22 is composed of a metal film 22a in a scale shape, a binder, a drying aid, a control agent, and the like. From the viewpoint of ease of application by a spray gun, the viscosity of the paint is preferably in the range of 50 to 1000[ cp ] (measurement temperature of 23 ℃).

The metal thin film 22a is aluminum formed in a scale shape, and has a thickness dimension in a range of 15 to 150nm, more preferably 20 to 80 nm. The average value of the dimensions of the metal thin film 22a in the longitudinal direction and the transverse direction (hereinafter referred to as the longitudinal dimension and the transverse dimension) perpendicular to the thickness direction is preferably 0.35 to 78 μm, which is the same as the lens height h of the unit lens 231. Here, the same as the lens height h includes not only the case where the longitudinal dimension and the lateral dimension of the metal thin film are equal to the lens height h but also the case where the metal thin film is similar to the lens height h (for example, a dimension range of-30% to +30% with respect to the lens height h).

Here, when the metal thin film 22a is arranged substantially parallel to the non-lens surface 233, when external light enters the non-lens surface 233, the external light may be reflected by the non-lens surface 233 and reach the observer side, and in this case, the contrast of the image may be reduced. Therefore, by making the longitudinal dimension and the lateral dimension of the metal thin film 22a equal to the lens height h as described above, it is possible to suppress the metal thin film 22a from being arranged substantially parallel to the non-lens surface 233 when the paint is applied to the back surface side of the lens layer 23. Thus, even if external light enters the non-lens surface 233, the reflection layer 22 can diffuse the external light at the end of the metal thin film, and reflection to the viewer can be suppressed as much as possible.

From the viewpoint of securing the light reflection function as the reflection layer, the metal thin film 22a is preferably contained in a range of 3 to 15% by weight relative to the weight of the entire paint.

The binder is a transparent adhesive made of a thermosetting resin, and is a base material for forming the reflective layer 22. In the present embodiment, a urethane-based thermosetting resin is used as the binder, but the binder is not limited to this, and an epoxy-based thermosetting resin may be used, or an ultraviolet-curable resin may be used. The binder may be used as a two-part curable type by adding a curing agent, and may be a urethane resin, a polyisocyanate, or the like, or an epoxy resin, an amine, or the like.

The drying aid is a solvent for adjusting the drying time of the coating material applied to the lens layer to a predetermined time, and is a slow-drying solvent. In the present embodiment, the drying aid is contained in the paint in a predetermined amount so that the time until the paint applied to the rear surface side of the lens layer 23 is dried is about 1 hour. The drying aid may be, for example, propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether, diisobutyl ketone, or a mixed solvent of 3-methoxy-1-butyl acetate.

The control agent is a solvent for controlling the orientation of the metal thin film 22a contained in the coating material. By including the control agent in the coating material, the metal thin film 22a can be disposed substantially parallel to the lens surface 232. Examples of the control agent include silica, alumina, aluminum hydroxide, an acrylic oligomer, and silicon.

From the viewpoint of ensuring the light reflection characteristics of the reflection layer 22 well and ensuring the appearance of the rear surface side of the reflection panel 20 well, as shown in fig. 3 b, the thickness T (film thickness) of the reflection layer 22 in the direction perpendicular to the lens surface 232 at the center portion Q of the lens surface 232 in the arrangement direction of the unit lenses 231 is preferably formed in the range of 8 μm+.t+.15 μm.

If the thickness T of the reflective layer 22 is less than 8 μm, the reflectance of the reflective layer 22 may be reduced, and the image light may not be sufficiently reflected, and the portion exposed to the rear surface side of the reflective layer 22 may be coated or the portion not coated with the coating film may be uneven or blurred in appearance, which may deteriorate the appearance of the rear surface side of the reflective layer 20, which is not preferable.

In addition, when the thickness T of the reflective layer 22 is larger than 15 μm, a part of the metal thin film 22a included in the reflective layer 22 is not arranged substantially parallel to the lens surface but is arranged substantially perpendicular to the lens surface, and the appearance of the rear surface side of the reflective layer 22 is uneven, which may deteriorate the appearance of the rear surface side of the reflective screen 20, which is not preferable.

The reflective layer 22 is not limited to the resin containing the scaly metal thin film 22a, and may be formed by vapor deposition, sputtering of a metal material having light reflection characteristics such as aluminum, silver, or nickel, or transfer of a metal foil. In this case, the thickness of the reflective layer sometimes becomes very thin (e.g) Therefore, the reflection screen 20 may be provided with a light shielding layer for suppressing the leakage of the light on the back surface side of the reflection layer 22 from the viewpoint of suppressing the leakage of the image light on the back surface side of the reflection layer 22 or the leakage of the light from the light transmitting/reflecting layer 22 on the back surface side to the image source side.

The surface layer 25 is a layer provided on the image source side (viewer side) of the base material layer 24. The surface layer 25 of the present embodiment forms the outermost surface of the reflection screen 20 on the image source side.

The surface layer 25 of the present embodiment has a hard coat function and an antiglare function, and is formed as follows: an ionizing radiation-curable resin such as an ultraviolet-curable resin (for example, urethane acrylate) having a hard coat function is applied to the surface of the base material layer 24 on the image source side, the film thickness of the coating film is made to be about 10 μm to 100 μm, and fine irregularities (matte shapes) or the like are transferred to the surface of the resin film and cured, whereby the fine irregularities are imparted to the surface.

The surface layer 25 is not limited to the above examples, and functions required for providing one or more of an antireflection function, an antiglare function, a hard coat function, an ultraviolet absorbing function, an antifouling function, an antistatic function, and the like may be appropriately selected. As the surface layer 25, a touch panel layer or the like may be provided.

The surface layer 25 may be further provided with a layer having an antireflection function, an ultraviolet absorption function, an antifouling function, an antistatic function, and the like as another layer between the surface layer 25 and the base material layer 24.

The surface layer 25 may be formed by bonding a layer separate from the base layer 24 to the base layer 24 with an adhesive material or the like (not shown), or may be formed directly on the surface of the base layer 24 opposite to the lens layer 23 (image source side).

Referring back to fig. 2, a case will be described in which image light and external light are incident on the reflective screen 20 of the present embodiment. In fig. 2, for easy understanding, the refractive indices of the surface layer 25, the coloring layer 242, the light diffusion layer 241, and the lens layer 23 are equal, and the light diffusion effect of the light diffusion layer 241 on the image light L and the external light G and the like are omitted.

As shown in fig. 2, most of the image light L1 projected from the image source LS enters from below the reflecting screen 20, passes through the surface layer 25 and the base material layer 24, and enters the unit lenses 231 of the lens layer 23.

Then, the image light L1 is incident on the lens surface 232, reflected by the reflective layer 22, and emitted from the reflective screen 20 in a substantially front direction toward the observer O side.

At this time, as described above, the image light L1 formed by the red, green, and blue laser light can be transmitted through the colored layer 242 containing the materials a to D with little absorption. Therefore, the image light L1 efficiently reaches the observer O, and therefore the reflective screen 20 of the present embodiment can display an image brightly with good contrast.

Since the image light L1 is projected from below the reflective screen 20 and the angle β (see fig. 3 (b)) is larger than the incidence angle of the image light L1 at each point in the vertical direction of the screen of the reflective screen 20, the image light L1 does not directly enter the non-lens surface 233, and the non-lens surface 233 does not affect the reflection of the image light L1.

On the other hand, as shown in fig. 2, unnecessary external light G (G1, G2) such as illumination light is mainly incident from above the reflective screen 20, passes through the surface layer 25 and the base material layer 24, and is incident on the unit lenses 231 of the lens layer 23. Here, most of the unnecessary external light G (G1, G2) such as illumination light, other than the red, green, and blue wavelengths, is absorbed in the colored layer 242, and the light of the red, green, and blue wavelengths is mainly incident on the unit lens 231.

A part of the external light G1 entering the unit lens 231 enters the non-lens surface 233, but is diffused at the end of the metal thin film 22a of the reflection layer 22 formed on the back surface side of the non-lens surface 233, and the light quantity thereof is greatly reduced from the image light L1 even when reaching the observer O side.

In addition, a part of the external light G2 is reflected by the lens surface 232 mainly toward the lower side of the reflecting screen 20, does not directly reach the observer O side, and even when reaching the observer O side, the light quantity thereof is greatly reduced from the image light L1.

Therefore, the reflection panel 20 can suppress a decrease in image contrast due to the external light G1, G2, or the like.

As described above, the reflecting screen 20 of the present embodiment exhibits the following effects.

The reflection screen 20 of the present embodiment includes a base layer 24, a lens layer 23 formed in a fresnel lens shape on the back surface side of the base layer 24, and a reflection layer 22 provided on the back surface side of the lens layer 23, and a light absorbing portion (colored layer 242) having wavelength selectivity is provided on the image source side of the reflection layer 22. This reduces reflection of external light and improves contrast of the reflective screen 20.

Further, by forming the light absorbing portion by mixing a material having wavelength selectivity into the colored layer 242 constituting the base material layer 24, the base material layer 24 having a function of the light absorbing portion can be manufactured by a simple process such as coextrusion molding.

In the reflection panel 20 of the present embodiment, the light absorbing portion contains two or more kinds of materials having wavelength selectivity, each of which has a light absorption band in a wavelength band that does not include the wavelengths of red, green, and blue laser light. Thus, the reflection screen 20 can efficiently reflect the red, green, and blue laser light projected from the image source to the observer side to suppress the decrease in luminance, and can absorb unnecessary light such as external light to suppress the reflection to the observer side as much as possible.

[ embodiment 2 ]

Next, a reflecting screen according to embodiment 2 will be described.

Fig. 5 is a diagram illustrating the layer structure of the reflection screen 120 according to embodiment 2, and corresponds to fig. 2.

As shown in fig. 5, the reflection panel 120 of embodiment 2 is different from the reflection panel 20 of embodiment 1 in that a light absorbing portion including a material having wavelength selectivity is provided on the lens layer 123 instead of the colored layer 242 of the base material layer 24. Therefore, the same reference numerals are given to the portions that realize the same functions as those of embodiment 1, or the same reference numerals are given to the portions at the end, and the duplicate description is omitted as appropriate.

The lens layer (light absorbing portion) 123 is formed in the same shape as that of embodiment 1. The lens layer 123 of the present embodiment is formed by including the same materials as the materials a to D having wavelength selectivity included in the colored layer 242 of embodiment 1 in the resin for forming the lens layer 23 of embodiment 1. Thus, the lens layer 123 can efficiently transmit the red, green, and blue laser light projected from the image source, and can absorb light outside the wavelength bands of red, green, and blue.

The base material layer 124 is a sheet-like base material that is the base of the reflection panel 120, and in the present embodiment, is composed of the light diffusion layer 241, and the coloring layer is omitted.

As described above, the reflection panel 120 of the present embodiment can reduce reflection of external light and improve contrast, as in the reflection panel 20 of embodiment 1.

In addition, by forming the light absorbing portion by mixing a material having wavelength selectivity into the resin constituting the lens layer 123, the lens layer 123 having the function of the light absorbing portion can be manufactured by a simple process.

Further, the reflective panel 120 of the present embodiment can omit the colored layer provided on the base material layer of embodiment 1, and therefore can simplify the layer structure as compared with the reflective panel 20 of embodiment 1, and can improve the manufacturing efficiency and reduce the manufacturing cost.

[ embodiment 3 ]

Next, a reflecting screen according to embodiment 3 will be described.

Fig. 6 is a diagram illustrating the layer structure of the reflection screen 220 according to embodiment 3, and corresponds to fig. 2.

As shown in fig. 6, the reflection panel 220 of embodiment 3 is different from the reflection panel 120 of embodiment 2 in that a light absorbing portion including a material having wavelength selectivity is provided on the surface layer 225 instead of the lens layer 123. Therefore, the same reference numerals are given to the portions that realize the same functions as those of embodiment 2, or the same reference numerals are given to the portions at the end, and the duplicate description is omitted as appropriate. The lens layer 23 of the present embodiment is formed by the same structure as the lens layer 23 of embodiment 1.

The surface layer (light absorbing portion) 225 is formed in the same shape as in embodiment 2. The surface layer 225 of the present embodiment is formed by adding the same materials as the materials a to D having wavelength selectivity included in the lens layer 123 of the above-described embodiment 2 to the resin forming the surface layer 25 of embodiment 1.

As described above, the reflection panel 220 of the present embodiment can reduce reflection of external light and improve contrast, as in the reflection panel 120 of embodiment 2.

In the reflecting screen 220 of the present embodiment, the light absorbing portion is formed by mixing a material having wavelength selectivity into the resin constituting the surface layer 225, and the surface layer 225 having the function of the light absorbing portion can be produced by a simple process.

In the reflecting screen 220 of the present embodiment, since the light absorbing portion is formed by including the material having wavelength selectivity in the surface layer 25, specular reflection components on the surface of the reflecting screen 20 can be reduced, and so-called ceiling artifacts and the like caused by reflection of external light can be reduced.

[ embodiment 4 ]

Next, a reflecting screen according to embodiment 4 will be described.

Fig. 7 is a diagram illustrating the layer structure of the reflection screen 320 according to embodiment 4, and corresponds to fig. 2.

As shown in fig. 7, the reflection panel 320 according to embodiment 4 differs from the reflection panel 120 according to embodiment 2 described above in that a light absorbing layer (light absorbing portion) 326 containing a material having wavelength selectivity is provided on the back surface of the base layer 124 instead of providing a light absorbing portion containing a material having wavelength selectivity on the lens layer 123. Therefore, the same reference numerals are given to the portions that realize the same functions as those of embodiment 2, or the same reference numerals are given to the portions at the end, and the duplicate description is omitted as appropriate. The lens layer 23 of the present embodiment is formed by the same structure as the lens layer 23 of embodiment 1.

The reflection screen 320 includes a surface layer 25, a base layer 124, a light absorbing layer 326, a lens layer 23, and a reflection layer 22 laminated in this order from the image source side.

The light absorbing layer 326 is a sheet-like member in which a plurality of absorbing layers containing materials a to D having different wavelength selectivities (see fig. 4 (a) to (D)) are laminated. Specifically, the light absorbing layer 326 includes 4 layers, that is, a 1 st absorbing layer 326a containing a material a having wavelength selectivity, a 2 nd absorbing layer 326B containing a material B having wavelength selectivity, a 3 rd absorbing layer 326C containing a material C having wavelength selectivity, and a 4 th absorbing layer 326D containing a material D having wavelength selectivity, which are laminated in this order from the observer side.

Each of the absorption layers (326 a to 326 d) is formed by containing the above-described material having wavelength selectivity in a light-transmitting resin (for example, a PC (polycarbonate) resin, an MS (methyl methacrylate-styrene) resin, an MBS (methyl methacrylate-butadiene-styrene) resin, a TAC (cellulose triacetate) resin, a PEN (polyethylene naphthalate) resin, a PET (polyethylene terephthalate) resin, a PMMA (polymethyl methacrylate) resin) or the like. The light absorbing layer 326 is formed by appropriately bonding the absorbing layers (326 a to 326 d) with a bonding layer or the like, not shown, for example.

The order of stacking the 1 st to 4 th absorbent layers (326 a to 326 d) is not limited to the above, and the layers may be stacked in different orders. The light absorbing layer 326 is described with an example of being disposed on the back surface of the base layer 124, but is not particularly limited as long as it is disposed on the observer side of the reflective layer 22, and may be disposed on the image source side of the base layer 124, the image source side of the surface layer 25, between the lens layer 23 and the reflective layer 22, or the like, for example.

As described above, the reflection panel 320 of the present embodiment can reduce reflection of external light and improve contrast, as in the reflection panel 120 of embodiment 2.

In the reflection panel 320 of the present embodiment, the light absorbing layer 326 is formed of absorbing layers (326 a to 326 d) of different plural kinds of materials having wavelength selectivity, and therefore the light absorbing layer 326 can be set by selecting the absorbing layer to be used according to the required optical characteristics and the like.

[ embodiment 5 ]

Next, a reflecting screen according to embodiment 5 will be described.

Fig. 8 is a diagram illustrating the layer structure of the reflection screen 420 according to embodiment 5, and corresponds to fig. 2.

Fig. 9 is a partial enlarged view of the light absorbing layer 426 of embodiment 5 as seen from the observer side.

As shown in fig. 8, the reflection panel 420 of embodiment 5 is different from the reflection panel 120 of embodiment 2 in that a light absorbing layer 426 containing a material having wavelength selectivity is provided on the back surface side of the base material layer 124 instead of providing a light absorbing portion containing a material having wavelength selectivity on the lens layer 123. Therefore, the same reference numerals are given to the portions that realize the same functions as those of embodiment 2, or the same reference numerals are given to the portions at the end, and the duplicate description is omitted as appropriate. The lens layer of the present embodiment is formed using the same structure as the lens layer of embodiment 1.

The reflection screen 420 includes a surface layer 25, a base layer 124, a light absorbing layer 426, a lens layer 23, and a reflection layer 22 laminated in this order from the image source side.

As shown in fig. 9, the light absorbing layer 426 is a sheet-like member patterned to selectively transmit image light formed by red, green, and blue laser light, respectively, in red, green, and blue regions R, G, and B.

Here, the red region R of the light absorbing layer 426 contains, in addition to the above-described materials a to D having wavelength selectivity shown in fig. 4, a material that absorbs a wavelength band of blue laser light LB (wavelength 465 nm) and green laser light LG (wavelength 525 nm), and transmits mainly red laser light LR1 (wavelength 638 nm) and/or LR2 (wavelength 642 nm) out of incident light (visible light).

Similarly, the green region G of the light absorbing layer 426 contains, in addition to the materials a to D having wavelength selectivity shown in fig. 4, a material that absorbs the wavelength bands of blue laser light LB (wavelength 465 nm) and red laser light LR1, LR2 (wavelengths 638nm, 642 nm), and transmits mainly the green laser light LG (wavelength 525 nm) among the incident light.

The blue region B of the light absorbing layer 426 contains, in addition to the above-described materials a to D having wavelength selectivity shown in fig. 4, a material that absorbs wavelength bands of red laser light LR1, LR2 (wavelengths 638nm, 642 nm) and green laser light LG (wavelength 525 nm), and transmits mainly blue laser light LB (wavelength 465 nm) among the incident light.

In the light absorbing layer 426 of the present embodiment, the red region R, the green region G, and the blue region B are each formed in a rectangular shape having a longer vertical direction, and are formed in a so-called stripe-like arrangement such that the red region R, the green region G, and the blue region B are sequentially repeated in a cycle in the horizontal direction of the screen and are continuous in the vertical direction of the screen in the same color region.

In the light absorbing layer 426, a black region BL is provided at the boundary between the red region R, the green region G, and the blue region B, and the black region BL is provided to increase the black feeling of the display screen of the reflective screen 420 and to improve the contrast.

The black region BL is formed by adding a dark coloring agent such as black to a resin serving as a base material. For example, a black dye, pigment, etc., black carbon, graphite, black iron oxide, etc., metal salt, etc., are preferably used as the colorant for forming the black region BL, and PET resin, PC resin, MS resin, MBS resin, TAC resin, PEN resin, acrylic resin, etc., may be used as the base material.

The red, green, and blue regions R, G, B are formed to have a vertical dimension of 10 to 400 μm and a horizontal dimension of 10 to 400 μm, and the interval between the regions (the width of the black region BL) is formed to have a width of 5 to 50 μm, for example.

The black region BL may be formed in a line shape extending in the vertical direction of the screen or the horizontal direction of the screen, or may be formed in a shape surrounding the red region R, the green region G, and the blue region B, respectively. The black region BL may be omitted as needed.

The red, green, and blue regions R, G, B can be formed in shapes other than rectangular, for example, polygonal shapes such as circular shapes and hexagonal shapes.

The light absorbing layer 426 is manufactured, for example, as follows.

The red, green, and blue regions R, G, B of the light absorbing layer 426 can be formed by applying offset printing, photolithography, an inkjet method, or the like to a transparent substrate, and ink forming the red, green, and blue regions R, G, B can be easily ejected by the inkjet method.

The black region BL can be formed by applying a chromium vapor deposition method, a film transfer method, an inkjet method, or the like to the transparent substrate, but the inkjet method is simpler.

When the black region BL is provided, the black region BL is formed as a partition wall in advance, and ink for forming red, green, and blue regions R, G, B is ejected by an inkjet method to the matrix-like regions partitioned by the partition wall (black region BL) to form red, green, and blue regions R, G, B, thereby producing the light absorbing layer 426. Then, the fabricated light absorbing layer 246 is bonded to the back surface of the base material layer 124.

The light absorbing layer 426 may be directly formed on the back surface side of the base layer 124 by an inkjet method or the like.

(other modes)

Fig. 10 is a view showing another embodiment of the light absorbing layer of embodiment 5, and corresponds to fig. 9.

The light absorbing layer 426 is not limited to the manner shown in fig. 9 described above. For example, as shown in fig. 10, the light absorbing layer 426 may be formed by a so-called mosaic arrangement in which the red region R, the green region G, and the blue region B are sequentially repeated in the left-right direction of the screen and the up-down direction of the screen.

Instead of the regular arrangement, the red region R, the green region G, and the blue region B may be arranged randomly (irregularly).

The light absorbing layer 426 is described with an example of being disposed on the back surface side of the base material layer 124, but is not particularly limited as long as it is disposed on the observer side of the reflective layer 22, and may be disposed on the image source side of the base material layer 124, the image source side of the surface layer 25, between the lens layer 23 and the reflective layer 22, or the like, for example. When the light absorbing layer 426 is provided between the lens layer 23 and the reflective layer 22, the black region BL, the red region R, the green region G, and the blue region B are formed on the back surface side of the lens layer 23 by an inkjet method or the like, the light absorbing layer 426 is formed, and the reflective layer 22 is formed on the back surface side thereof.

As described above, the reflection panel 420 of the present embodiment can reduce reflection of external light and improve contrast, as in the reflection panel 120 of embodiment 2.

The reflection screen 420 of the present embodiment can sufficiently absorb external light by sufficiently securing the transmittance of image light of red, green, and blue laser beams by patterning the red region R, the green region G, and the blue region B.

Further, in the reflection screen 420 of the present embodiment, the black region BL is provided at the boundary between the red region R, the green region G, and the blue region B, and thus the black feeling of the display screen of the reflection screen 420 can be increased, and the contrast can be improved.

[ embodiment 6 ]

Next, a reflection screen 520 according to embodiment 6 will be described.

Fig. 11 is a diagram illustrating the layer structure of the reflection screen 520 according to embodiment 6, and corresponds to fig. 2.

As shown in fig. 11, the reflection screen 520 of embodiment 6 is different from the reflection screen 20 of embodiment 1 described above in that: a coloring layer 242 (light absorbing portion) containing a material having wavelength selectivity is provided as a light absorbing portion on the image source side of the base material layer 524 containing no diffusing agent; the surface layer 525 has an optical shape on the image source side; the reflective layer 522 is formed only on the lens face 232; the light shielding layer 527 is provided; etc. Therefore, the same reference numerals are given to the portions that realize the same functions as those of embodiment 1 or the same reference numerals are given to the portions at the end, and the duplicate description is omitted as appropriate. The lens layer 23 of the present embodiment is similar to the lens layer 23 of embodiment 1.

The base layer 524 is a layer having light transmittance, and does not contain a diffusing agent. The base material layer 524 may be formed using the resin shown in embodiment 1 as the base material of the light diffusion layer 241, and is preferably, for example, PET (polyethylene terephthalate) resin, PC (polycarbonate) resin, MS (methyl methacrylate-styrene) resin, MBS (methyl methacrylate-butadiene-styrene) resin, TAC (cellulose triacetate) resin, PEN (polyethylene naphthalate) resin, acrylic resin, or the like.

The colored layer (light absorbing portion) 242 is a layer similar to the colored layer 242 of embodiment 1, and is a light absorbing portion that transmits light in a specific wavelength band among incident light and absorbs other light.

In the present embodiment, the coloring layer 242 is provided on the image source side of the base layer 524, but the present invention is not limited to this, and may be provided on the back side of the base layer 524.

As shown in fig. 11, the reflective layer 522 of the present embodiment is formed on the lens surface 232, but is not formed on the non-lens surface 233. The reflective layer 522 is formed by vapor deposition, sputtering of a metal material having light reflection characteristics such as aluminum, silver, or nickel, or transfer of a metal foil.

The reflective layer 522 may be formed on the lens surface 232 and the non-lens surface 233.

The light shielding layer 527 is a layer formed on the back surface side of the reflective layer 522, and is a layer in which the concave-convex shape formed by the unit lenses 231 is buried so that the surface on the back surface side of the reflective screen 520 is planar.

The light shielding layer 527 has light absorptivity and has a very small thickness (for example, a thickness of suppressing image light from forming by vapor deposition or the like) The reflection layer 522 of (a) leaks to the back side, or the light on the back side leaks to the image source side through the reflection layer 522. In addition, the reflective layer 522 has a function of protecting the reflective layer 522 from degradation, breakage, peeling, or the like.

The light shielding layer 527 may have, for example, an ultraviolet absorption function, an antifouling function, or the like, or may have no light absorption property in the case where there is no problem with external light or the like entering the reflective screen 520 from the back surface side.

Fig. 12 is a diagram illustrating a surface layer 525. Fig. 12 (a) shows a case where the surface layer 525 is viewed from the image source side front direction, and fig. 12 (b) is an enlarged view showing a part of the cross section of the surface layer 525 in a cross section parallel to the screen left-right direction and the thickness direction of the reflection screen 520.

The surface layer 525 of the present embodiment has a lenticular lens shape in which unit surface lenses 5251 protruding toward the image source side are arranged on the image source side surface.

The unit surface lenses 5251 are partially cylindrical and are arranged in the left-right direction (X direction) of the screen with the vertical direction (Y direction) of the screen as the ridge line direction (longitudinal direction). The cross-sectional shape of the unit surface lens 5251 shown in fig. 12 is a partial shape of a circle. The shape of the unit surface lens 5251 is not limited to the above, and may be, for example, a partial shape of an elliptical cylinder shape or a cylindrical lens shape composed of a plurality of curved surfaces.

By providing the surface layer 525 formed with such a unit surface lens 5251, the image light is diffused in the screen left-right direction by the unit surface lens 5251, and the viewing angle of the reflection screen 520 in the screen left-right direction (X direction) can be sufficiently ensured.

From the viewpoint of diffusing the image light in the horizontal direction of the screen and securing a sufficient viewing angle in the horizontal direction of the screen, it is preferable that the arrangement pitch P2 of the unit surface lenses 5251 be in the range of 30 to 120 μm and the height h2 of the unit surface lenses 5251 (the dimension from the top of the unit surface lenses 5251 in the screen thickness direction to the point which is the valley bottom between the unit surface lenses 111) be in the range of 10 to 25 μm. The unit surface lenses 5251 of the present embodiment are arranged adjacent to each other with the lens width W2 equal to the arrangement pitch P2, but the present invention is not limited thereto and may be set to W2> P2.

The thickness of the surface layer 525 is formed to 15 to 35 μm.

The surface of the unit surface lens 5251 of the present embodiment on the image source side (+z side) is a rough surface having a fine uneven shape. When the surface of the surface layer 525 on the image source side is roughened, an effect of reducing reflection of external light such as illumination light or sunlight, an effect of expanding the viewing angle in the vertical direction (Y direction) of the screen, and the like can be obtained.

The surface of the unit surface lens 5251 may be a smooth surface having no fine uneven shape as described above, without being limited thereto.

The surface layer 525 of the present embodiment may be formed using an ultraviolet curable resin such as urethane acrylate or epoxy acrylate, an ionizing radiation curable resin such as an electron beam curable resin, or a thermoplastic resin.

The surface layer 525 is not limited to the above example, and may have other lens shapes or may not have a lens shape.

From the viewpoint of improving contrast of an image and displaying a bright and good image, it is preferable that the reflection screen 520 has a maximum value of reflectance in a region of ±50nm centered on wavelengths of red, green, and blue lasers in a distribution of spectral reflectance in a visible light region (400 to 700 nm).

When the average value of the reflectance of the reflection plate 520 at the wavelengths of the red, green, and blue lasers (LR 1, LR2, LG, LB) is PA [% ], and the average value of the spectral reflectance per 1nm in the visible light region (400 to 700 nm) is PB [% ], the ratio PA/PB of the average values is preferably PA/PB of 1.16 or more.

In the case of PA/PB <1.16, there is a problem that the contrast of the image is lowered or the displayed image is darkened by external light entering the reflective screen. Therefore, the ratio PA/PB preferably satisfies PA/PB.gtoreq.1.16.

The reflection screen 520 of the present embodiment has a maximum value of reflectance in a region of ±50nm centered on the wavelengths of red, green, and blue lasers (LR 1, LR2, LG, LB), and satisfies PA/PB of 1.16 or more.

In the present embodiment, the above 4 types of light (LB, LG, LR1, LR 2) are shown as the laser light when calculating the average value PA, but a plurality of light sources having 1 or more wavelengths may be used for each of the 3 colors of red, green, and blue in the laser light source of the image source LS. Therefore, the average PA may be an average of 3 wavelengths, such as red, green, and blue lasers (LR 1, LG, and LB).

Further, the reflective screen 520 preferably has a color difference Δe between chromaticity of black display and chromaticity of achromatic color as a reference color ^* ab satisfies ΔE ^* ab is less than or equal to 2.4. This is because, in the color difference ΔE ^* ab>2.4, a color tone deviation occurs during black display, and no achromatic color can be visually recognized. The reflective screen 520 of the present embodiment satisfies Δe ^* ab≤2.4。

The image light and the external light incident on the reflection screen 520 of embodiment 6 will be described.

As shown in fig. 11, most of the image light L1 projected from the image source LS is reflected by the reflective layer 522 toward the observer O side as in embodiment 1. At this time, the image light L1 formed by the red, green, and blue laser light is hardly absorbed in the colored layer 242. Further, the unit surface lenses 5251 of the surface layer 525 diffuse in the left-right direction of the screen and are emitted to the observer O side, so that the viewing angle in the left-right direction of the screen can be sufficiently ensured.

Most of the external light G (G1, G2) incident on the reflective screen 520 is absorbed by the colored layer 242 in a wavelength band other than red, green, and blue. In addition, as in embodiment 1, a part of the external light G2 is reflected by the reflective layer 522 to be directed to the lower side of the reflective screen 520, and does not directly reach the observer O, and even when it reaches, the light quantity is significantly reduced from that of the image light L1. In addition, a part of the external light G1 enters the non-lens surface 233 and is absorbed by the light shielding layer 527.

Therefore, according to this aspect, as in embodiment 1 and the like, reflection of external light incident on the reflective screen 520 can be reduced, and contrast of a displayed image can be improved, so that a good image can be displayed.

(other modes)

As for the light absorbing portion, the material having the above-described selective wavelength may be kneaded into a material forming the lens layer 23, the lens layer 23 may be used as the light absorbing portion, or may be kneaded into a material forming the base material layer 524, and the base material layer 524 may be used as the light absorbing portion. In addition, the reflection layer 522 may be formed by kneading a material having wavelength selectivity into the material containing a metal thin film shown in embodiment 1, and the reflection layer may be used as a light absorbing portion.

In addition, from the viewpoint of improving the contrast of an image displayed on the reflecting screen, it is preferable that the above embodiments 1 to 5 satisfy that the spectral reflectance distribution of the reflecting screen in the visible light region has a maximum value of reflectance in a region of ±50nm centered on the wavelength of red, blue, and green laser light, and that the ratio PA/PB be equal to or greater than 1.16.

(evaluation about reflective Screen)

Here, reflection panels of measurement examples 1 to 4 were prepared, and spectral reflectances in the visible light region (400 to 700 nm) were measured at a point a at the center of the screen (display region) and at a point B at the center of the lower end of the screen (display region) at a wavelength interval of 0.5 nm.

The reflective panels of measurement examples 1 to 4 used in the measurement have a common structure except for the colored layer 242, as described below.

Picture size: 947mm in longitudinal direction and 1674mm in transverse direction (75 inches)

Surface layer 525: the unit surface lens 5251 has a pitch p1=100 μm, a lens height h1=15 μm, and a fine concave-convex shape (matte shape) on the surface

Substrate layer 524: polyethylene terephthalate resin having a thickness of 250 μm and a transmittance of 59%

Lens layer 23: the arrangement pitch p2=100 μm of the unit lenses 131 made of ultraviolet curable resin, the angle α at the center of the screen in the lateral direction at the lower end of the screen being about 5 °, the angle α at the center of the screen in the lateral direction at the upper end of the screen being about 20 °, the angle β being constant at 90 ° in the arrangement direction of the unit lenses 131

Reflective layer 522: formed only on the lens face 323 by aluminum vapor deposition

In the measurement, the screen of each measurement example does not include the light shielding layer 527, and a black screen (black cloth screen) is disposed on the back surface side of the reflection layer instead of the light shielding layer 527.

The colored layers of the reflective screen of each measurement example are as follows.

Measurement of the colored layer 242 of the reflective screen of example 1: the light absorption characteristic has selective wavelength, and the ratio PA/PB is more than or equal to 1.16.

Measurement of the colored layer 242 of the reflective screen of example 2: the light absorption characteristic has selective wavelength, and the ratio PA/PB is more than or equal to 1.16.

Measurement of the colored layer of the reflective screen of example 3: the light absorption characteristics were not wavelength selective, and the transmittance (total light transmittance) was 70%.

Measurement of the colored layer of the reflective screen of example 4: the light absorption characteristics were not wavelength selective, and the transmittance (total light transmittance) was 59%.

The reflective panels of measurement examples 1 and 2 correspond to the example of the reflective panel of embodiment 6, and the reflective panels of measurement examples 3 and 4 correspond to the comparative example.

The measurement method is as follows.

The spectral reflectance was measured by a spectrophotometer (UV-2450/MPC-2200, manufactured by Shimadzu corporation). In the measurement, a sample having a 60mm square cut about the point A and the point B of the reflecting plate of each measurement example was placed in the measurement chamber of the spectrophotometer, respectively, and the measurement was performed. The wavelength region to be measured is 400 to 700nm corresponding to the visible light region, and the measurement is performed every 0.5nm as described above.

TABLE 1

Fig. 13 is a graph showing measurement results of spectral reflectances of the reflection panels of measurement examples 1 to 4. Fig. 13 (a) shows the spectral reflectance distribution at point a, and fig. 13 (B) shows the spectral reflectance distribution at point B. In fig. 13 (a) and (b), the vertical axis represents reflectance [% ], and the horizontal axis represents wavelength [ nm ].

Table 1 shows the results obtained by obtaining the average value PA of the reflectances of the point a and the point B at the red, green, and blue lasers (LR 1, LR2, LG, LB) and the average value PB of the reflectances per 1nm in the visible light range (400 to 700 nm) based on the measurement results of fig. 13, and the values of the ratio PA/PB and the visual evaluation results of the images. As to the visual evaluation results shown in table 1, o indicates that a bright and good image with high contrast was visually recognized, and x indicates that a dark image with low contrast was visually recognized.

As shown in fig. 13, in the reflection panels of measurement examples 1 and 2, the spectral reflectance distribution in the visible light region (400 to 700 nm) has a maximum value of reflectance in a region of ±50nm centered on the wavelength of the red, green, and blue laser light (LR 1, LR2, LG, LB), but in the reflection panels of measurement examples 3 and 4, such a maximum value is not seen.

As shown in table 1, in the reflection panels corresponding to measurement examples 1 and 2 of the examples, the ratio PA/PB was 1.19 and 1.16 at the point a and 1.22 and 1.16 at the point B, respectively, and the preferable ranges of the ratio PA/PB were satisfied.

In contrast, in the reflective panels of measurement examples 3 and 4, the ratio PA/PB was 1.06 and 0.98 at the point a and 1.06 and 0.97 at the point B, respectively, and the preferable range of the ratio PA/PB was not satisfied.

As a result of actually projecting image light from the image source LS onto the reflective panels of measurement examples 1 to 4, the images displayed at the points a and B were confirmed from the position of the image source side front surface of the point a, which is the center of the screen, at a height of 1.5m from the ground under the bright room environment (illuminance 700lx at the point a), and as a result, as shown in table 1, the reflective panels of measurement examples 1 and 2, which correspond to the example, were visually recognized as high-contrast bright and good images, whereas the reflective panels of measurement examples 3 and 4 were low in contrast and dark in sharpness, compared with the reflective panels of measurement examples 1 and 2.

Therefore, the reflective screen preferably satisfies the ratio PA/PB.gtoreq.1.16 as described above.

The reflective screen of the present embodiment satisfies the ratio PA/PB of 1.16 or more, and therefore can suppress a decrease in contrast due to external light, and can display a bright and good image.

On the other hand, it can be seen that: even if the value of the ratio PA/PB satisfies the preferable range, there is a case where a white display or a black display is performed on the reflective screen, a variation in color tone may occur in an image or the like. Namely, it can be seen that: when the ratio PA/PB is increased to suppress a decrease in contrast of an image due to external light, there is a case where the color balance of the reflected light of the reflective screen is shifted, and color reproducibility is reduced.

The chromaticity of black displayed on the reflective screen is controlled by the reflected light of the external light (light of the wavelength of the visible light region) incident on the reflective screen, and the white display of the reflective screen is controlled by the spectral reflectance of the reflected light of the image light incident on the reflective screen.

Regarding black display of the reflective screen, preferably, L is made ^* a ^* b ^* The difference between the chromaticity of achromatic color as a reference color in the color space (CIE 1976) of the color system and the chromaticity of black display on the reflecting screen (i.e., the chromaticity of reflected light of external light), i.e., Δe ^* ab has a value of 2.4 or less (ΔE) ^* ab.ltoreq.2.4). Color difference delta E ^* When the value ab is greater than 2.4, a variation in color tone occurs in the black display of the reflective screen, and the color reproducibility is lowered when other color tone is added to black (achromatic color).

In addition, regarding white display of the reflective screen, when the difference between the maximum value and the minimum value of the reflectance at the wavelengths of the red, blue, and green lasers (LR 1, LR2, LG, LB) is Δr, Δr is preferably equal to or less than 2.6%. When Δr satisfies this range, the difference in reflectance between the lasers is reduced, so that the variation in color tone in white display can be reduced, and color reproducibility can be improved.

Here, a reflection sheet of measurement example 5 was further prepared, and the reflectance distribution in the visible light region (400 to 700 nm) at the point a was measured similarly to the reflection sheets of measurement examples 1 to 4. In the reflecting panel of this measurement example 5, the layers other than the colored layer 242 are the same as those of the reflecting panels of other measurement examples, and the ratio PA/pb=1.16, and the preferable range of the ratio PA/PB is satisfied.

Then, Δe of black display at point a was calculated in each of the reflection panels of measurement examples 1 to 5 ^* ab. First, the chromaticity of a standard white plate was measured by the spectrophotometer as a reference (reference), and a reflectance spectrum of a sample (a 60mm square sample centered on the point a) of the reflecting screen of each measurement example was obtained by actual measurement. Then, calculate the chromaticity value L for the standard D65 light source ^* 、a ^* 、b ^* From these values, the color difference ΔE of the black display is calculated ^* ab。

Further, for the reflection panels of measurement examples 1 to 5, the difference Δr between the maximum value and the minimum value of the reflectance at the wavelengths of the red, green, and blue lasers (LR 1, LR2, LG, LB) at point a was calculated.

Further, regarding the reflection screen of each measurement example, the hue at the point a in the bright room environment (illuminance 700lx at the point a) in the state where no image light is projected (black display state) and the hue at the point a in the state where image light forming a white screen is projected from the image source LS (illuminance 700lx at the point a) are visually evaluated, respectively. The visual evaluation was performed at a position of a height of 1.5m from the ground in the front direction of the image source side of a point a which is the center of the screen.

Fig. 14 is a graph showing measurement results of spectral reflectances at point a of the reflection panels of measurement examples 1 to 5, and the vertical and horizontal axes are the same as those of fig. 13. The graph shown in fig. 14 corresponds to the graph obtained by adding the measurement result of the reflection panel of measurement example 5 to the graph shown in fig. 13 (a).

TABLE 2

Table 2 shows the color difference ΔE between the black display at point A in the reflection screen of each measurement example and the achromatic color as a reference ^* ab. Reflectivity of each laser at point aThe difference Δr between the maximum value and the minimum value, and the result of visual evaluation. As to the visual evaluation results shown in table 2, o represents a deviation of no color tone, no color is recognized by visual perception, and x represents a deviation of color tone, no color is recognized by visual perception.

As shown in table 2, PA/pb=1.16 in the reflective screen of measurement example 5 satisfies the preferable range of the ratio PA/PB, but Δe in black display ^* ab is greater than 2.4, outside the preferred range. On the other hand, the reflective panels of measurement examples 1 to 4 were shown to have ΔE in black ^* ab is 2.4, 1.9, 1.8, 2.1 respectively, satisfying ΔE ^* ab≤2.4。

In the visual evaluation of the black display, the reflective panels of measurement examples 1 to 4 were also free of variation in color tone and visually recognized as achromatic, while the reflective panel of measurement example 5 was free of variation in color tone and visually recognized as chromatic.

As shown in table 2, in the reflective panels of measurement examples 1,2, and 5, Δr is 0.7% and 2.5%, respectively, and Δr is not more than 2.6%, respectively, and the preferable range of Δr is satisfied. On the other hand, in the reflective panels of measurement examples 3 and 4, Δr is 3.2% and 4.6%, and is greater than 2.6%, and the preferable range of Δr is not satisfied.

In the visual evaluation of the white display, the reflective panels of measurement examples 1,2, and 5 were also free of color variation and visually recognized as achromatic, while the reflective panels of measurement examples 3 and 4 were found to have color variation and visually recognized as achromatic.

As is clear from the above, the reflective panels of measurement examples 1 and 2 showed good achromatic color without color variation between black display and white display, while the reflective panels of measurement examples 3 and 4 showed color variation between white display and black display, respectively.

As described above, the chromaticity of the black display displayed by the reflective screen of the present embodiment is different from the chromaticity of the achromatic color as the reference color by the color difference Δe ^* ab satisfies ΔE ^* ab.ltoreq.2.4, and no variation in the color tone of black display, and good images can be displayed. In addition, the reflection screen of the present embodiment displays each laser beam in white Since the difference ΔR between the maximum value and the minimum value of the reflectance satisfies ΔR.ltoreq.2.6%, the white display does not have any deviation in color tone, and a good image can be displayed.

Other embodiments

While the preferred specific structure for carrying out the present invention has been described in detail, the present invention may be variously modified and further variously combined with the structure of the above-described embodiment within the scope not departing from the gist of the present invention.

(1) In the above embodiments, the case where 1 member of the reflecting screen is used as the light absorbing portion and the case where the light absorbing layer is disposed at one position between the members of the reflecting screen has been described, but the present invention is not limited to this, and a plurality of members of the reflecting screen may be used as the light absorbing portion, or the light absorbing portion may be disposed at a plurality of positions between the members of the reflecting screen. The light absorbing portion may be a member of the reflecting screen, and the light absorbing layer may be provided between the members of the reflecting screen.

(2) In embodiment 4, the reflection sheet 320 has the light absorbing layer 326 having a multilayer structure in which a plurality of absorbing layers (326 a to 326D) are laminated, but the present invention is not limited to this, and the materials a to D shown in fig. 4 may be mixed with a resin as a base material to form a single light absorbing layer 326.

(3) In embodiment 5 described above, the reflective screen 420 may omit the black region BL of the light absorbing layer 426. This can simplify the method for manufacturing the light absorbing layer 426 and improve the manufacturing efficiency.

(4) In embodiment 5, the light absorbing layer 426 is coated on each of the red region R, the green region G, and the blue region B, but the present invention is not limited thereto, and an ink may be prepared by mixing wavelength-selective materials contained in each region, and the light absorbing layer 426 may be formed on the image source side of the reflective layer 22 by coating the ink by a spray method or the like. For example, in the case of forming the light absorbing layer 426 between the reflective layer 22 and the lens layer 23, the ink may be applied to the back surface of the lens layer 23 by a spray method, and dried, and then the reflective layer 22 may be formed on the back surface of the formed light absorbing layer 426.

Symbol description

1. Image display system

20. 120, 320, 420, 520 reflecting screen

22. 522 reflective layer

23. 123 lens layer

24. 124, 524 substrate layer

241. Light diffusion layer

242. Coloring layer

25. 225, 525 surface layer

326. 426 light absorbing layer

30. Supporting plate

40. Bonding layer

231. Unit lens

232. Lens surface

233. Non-lens surface

Claims (9)

1. A reflective screen capable of reflecting image light formed by red, green and blue laser beams projected from an image source and observing the image light, characterized in that,

the reflecting screen is provided with:

a base material layer,

A lens layer formed in a Fresnel lens shape on a rear surface side, which is a side opposite to the image source side, of the base material layer, and

a reflection layer provided on the back side of the lens layer,

a light absorbing part with wavelength selectivity is arranged on the image source side of the reflecting layer,

the light absorbing part is a light absorbing layer which contains a material having wavelength selectivity and is arranged on the image source side of the reflecting layer,

the light absorbing layer is patterned to selectively transmit red regions of the image light formed by the red laser light, selectively transmit green regions of the image light formed by the green laser light, and selectively transmit blue regions of the image light formed by the blue laser light.

2. The reflective screen of claim 1, further comprising a surface layer forming an outermost surface of the reflective screen on the image source side.

3. A reflective screen capable of reflecting image light formed by red, green and blue laser beams projected from an image source and observing the image light, characterized in that,

The reflecting screen is provided with:

a base material layer,

A lens layer formed in a Fresnel lens shape on a rear surface side, which is a side opposite to the image source side, of the base material layer, and

a reflection layer provided on the back side of the lens layer,

a light absorbing part with wavelength selectivity is arranged on the image source side of the reflecting layer,

when the spectral reflectance of the reflecting screen is measured, the reflecting screen has a maximum value of reflectance in a region of ±50nm centered on the wavelength of the laser light of red, green, and blue.

4. A reflecting screen according to claim 3, wherein the light absorbing portion comprises two or more kinds of materials having wavelength selectivity, each having a light absorbing band in a wavelength band excluding the wavelengths of the laser light of red, green, and blue.

5. A reflecting screen according to claim 3, wherein when the average value of the reflectances at the wavelengths of the red, green and blue lasers is PA, the average value of the reflectances at the wavelengths of the light in the visible light region is PB, and the ratio thereof is PA/PB, the light absorbing portion satisfies:

PA/PB≥1.16。

6. the reflecting screen according to claim 5, wherein a chromaticity of the black display is different from a chromaticity of the achromatic color Δe as a reference ^* ab satisfies:

ΔE ^* ab≤2.4。

7. a reflective screen as claimed in claim 3, wherein the reflective screen further comprises a surface layer forming the outermost surface of the image source side of the reflective screen.

8. A reflecting screen according to claim 3, further comprising a light shielding layer formed on the back surface side of the reflecting layer, wherein the light shielding layer is a layer in which the concave-convex shape formed by the unit lens is buried so that the back surface side of the reflecting screen is planar.

9. An image display system, comprising:

a reflective screen as claimed in claim 1 or claim 3, and

and an image source for irradiating the reflecting screen with image light.