JP2014199316A - Transmission type screen, rear projection display unit and automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission type screen easy to manufacture and having excellent designability.SOLUTION: A transmission type screen includes a laminate body of a plurality of layers, configured to transmit video light incident from a light-incident surface side to a light-emitting surface side. The laminate body includes a portion curved to convex to one surface side. The laminate body includes, from the light-emitting surface side, a hard coat layer, a lenticular lens layer having a lenticular lens portion, and a diffusion layer for diffusing light, formed along a surface of the lenticular lens portion.

Description

  The present invention includes a transmissive screen having a curved surface for transmitting image light projected from the back side to the viewer side, a rear projection display device including the transmissive screen, and the rear projection display device. Related to the car.

  Conventionally, various display devices capable of displaying video have been incorporated into various systems. In recent years, the field of systems to which display devices are applied has further expanded, and display devices have been incorporated into systems related to daily life. For example, display devices have been applied to fields in which designability is very important, such as automobiles and amusement machines. A display device applied to such a field is not only expected to have a function of displaying an image, but is also required to be harmonized with the entire system from the viewpoint of design.

  Patent Document 1 discloses a method of manufacturing a transmission screen that has improved design by forming a three-dimensional curved surface.

JP 2012-159647 A

  However, the transmissive screen disclosed in Patent Document 1 has a problem that the manufacturing process of the transmissive curved screen is complicated due to the complicated structure of the optical functional layer provided in the transmissive screen. was there. In addition, since the optical functional layer has a complicated structure, there is a problem that it is difficult to bend the transmissive screen so as to form a curved surface.

  In view of the above problems, the present invention provides a transmission screen that is easy to manufacture and has excellent design, a rear projection display device including the transmission screen, and an automobile including the rear projection display device. Let it be an issue.

  The present invention will be described below.

  The invention according to claim 1 is a transmissive screen having a laminated body in which a plurality of layers are laminated, and transmits the image light incident from the light incident surface side to the light emitting surface side, and the laminated body has one surface. The laminated body is formed from the light exit surface side along the surface of the hard coat layer, the lenticular lens layer having the lenticular lens portion, and the surface of the lenticular lens portion. And a diffusing layer for diffusing light.

  According to a second aspect of the present invention, in the transmissive screen according to the first aspect, a Fresnel lens sheet having a Fresnel lens portion is provided on the light incident surface side of the laminate.

  According to a third aspect of the present invention, there is provided a rear projection display device comprising the transmissive screen according to the first or second aspect, and an image light source disposed on a light incident surface side of the transmissive screen.

  According to a fourth aspect of the present invention, in the rear projection display device according to the third aspect, the unit lenses constituting the lenticular lens unit are arranged in parallel in the horizontal direction.

  According to a fifth aspect of the present invention, in the rear projection display device according to the third aspect, unit lenses constituting the lenticular lens unit are arranged in parallel in the vertical direction.

  A sixth aspect of the present invention is an automobile including the rear projection display device according to the fifth aspect, wherein the rear projection display device is disposed so that the light exit surface can be viewed from the inside of the vehicle.

  According to the present invention, it is possible to provide a transmissive screen that is easy to manufacture and excellent in design, a rear projection display device including the transmissive screen, and an automobile including the rear projection display device.

It is a figure explaining one embodiment, and is a figure showing notionally the structure of the rear projection display device. It is a perspective view of a transmissive screen. It is sectional drawing of the horizontal direction explaining the laminated constitution of a transmissive screen. It is a front view of the transmission type screen explaining a Fresnel lens part. It is sectional drawing of the perpendicular direction of a transmissive screen.

  The above-described operation and gain of the present invention will be clarified from embodiments for carrying out the invention described below. Hereinafter, the present invention will be described based on embodiments shown in the drawings. However, the present invention is not limited to these embodiments. In the drawings shown below, the size and ratio of members may be exaggerated for easy understanding. Moreover, the code | symbol which becomes repeated may be abbreviate | omitted for legibility.

  FIG. 1 is a diagram for explaining one embodiment, and is a diagram conceptually showing a part of the internal structure of a rear projection display device 1 (hereinafter sometimes referred to as “display device 1”). .

The display device 1 includes a transmissive screen 10, and the video light I emitted from the video light source 3 is provided to the viewer through the transmissive screen 10. For example, the display device 1 is built in a dashboard portion of an automobile, and the viewer side surface of the transmissive screen 10 is disposed so as to be exposed in the vehicle, and provides an image to the viewer.
As can be seen from FIG. 1, the display device 1 includes a housing 2, an image light source 3, and a transmissive screen 10. In addition, although illustration is omitted, the display device 1 includes various components for functioning as a display device.

  The housing 2 is a member that forms an outer shell of the display device 1 and that accommodates most of the members constituting the display device 1 therein. The housing 2 has an opening capable of supporting the transmissive screen 10, and the transmissive screen 10 is fitted and attached to the opening.

The image light source 3 is disposed in the housing 2 and irradiates the image light on almost the entire light incident surface of the transmission screen 10 as diverging light whose irradiation area gradually expands. As such an image light source 3, a conventionally known light source, for example, a single tube type light source using DMD can be used. In the present embodiment, the image light source 3 is disposed below the center of the transmissive screen 10 on the back side (the side opposite to the observer side) of the transmissive screen 10.
Here, the light incident surface of the transmissive screen 10 means a surface of the transmissive screen 10 on the side where the image light source 3 is disposed. On the other hand, the light exit surface of the transmissive screen 10 means a surface directed toward the observer side.

  Next, the transmission screen 10 will be described. FIG. 2 is a perspective view of the transmission screen 10, and FIG. 3 is a cross-sectional view in the thickness direction of the transmission screen 10 in the horizontal direction along the line indicated by III-III in FIG. It is. As can be seen from FIGS. 1 and 2, the transmission screen 10 has a plate-like shape as a whole, but is formed in a convex curved surface whose center protrudes toward the viewer. Accordingly, it is possible to provide a screen having an excellent appearance and a display device including the screen.

  In the present embodiment, the transmission screen 10 having a curved surface convex toward the viewer will be described. However, the convex position is not particularly limited. Further, the convex direction is not limited, and may be convex on the back side (that is, concave when viewed from the observer side). Furthermore, it may be configured such that the direction of the unevenness is changed depending on the site by one transmission type screen.

  As can be seen from FIGS. 2 and 3, the transmission screen 10 has a plurality of layers laminated, and the laminate 11 and the Fresnel lens sheet 21 are arranged in the thickness direction. This will be described in detail below.

  The laminate 11 includes a hard coat layer 12, a lenticular lens 13 layer, and a diffusion layer 17 from the light exit surface side, and these are laminated.

The hard coat layer 12 is a layer provided on the outermost surface on the viewer side of the transmission screen 10 for the purpose of surface protection. The hard coat layer 12 can be formed as a transparent resin layer, and is preferably formed as a cured resin layer obtained by curing a curable resin from the viewpoint of resistance to scratches and surface contamination.
Specifically, an ionizing radiation curable resin, other known curable resins, or the like may be appropriately employed according to the required performance. Examples of the ionizing radiation curable resin include acrylate-based, oxetane-based, and silicone-based resins. For example, acrylate-based ionizing radiation curable resins include monofunctional (meth) acrylate monomers, bifunctional (meth) acrylate monomers, (meth) acrylate monomers such as trifunctional or higher (meth) acrylate monomers, urethane (meta ) Acrylate, epoxy (meth) acrylate, polyester (meth) acrylate and other (meth) acrylate ester oligomers or (meth) acrylate ester prepolymers. Examples of tri- or higher functional (meth) acrylate monomers include trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like.

Further, the hard coat layer 12 may be added with a function of improving the stain resistance. This can be achieved, for example, by adding a silicone compound, a fluorine compound, or the like. Further, as other functions, it may have a function of improving antistatic properties and water repellency.
As materials that can be used for improving the antistatic property, PEDOT-PSS (PEDOT (Poly (3,4-ethylenedioxythiophene); 3,4-ethylenedioxythiophene polymer) and PSS (polynesulfonate) are used for the electron conduction type. ); A styrene sulfonic acid polymer)), and the ionic conductive type includes lithium salt materials.
Examples of materials that can be used to improve water repellency include fluorine compounds.

  The lenticular lens 13 layer has a base portion 14 and a lenticular lens portion 15 formed on the surface of the base portion 14, and the lenticular lens portion 15 has a plurality of unit lenses 16 arranged in parallel.

  The base portion 14 is a portion serving as a base for forming the lenticular lens portion 15. Therefore, the base portion 14 has translucency, and is configured to have such strength that the lenticular lens portion 15 can be formed and held. Specific examples of the material constituting the base 14 include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, and ethylene-vinyl acetate copolymer. Polymer, saponified ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer elastomer, acid-modified polyolefin, styrene-butadiene-acrylonitrile copolymer, polyamide, polycarbonate, polysulfone, polyacetal, polymethyl methacrylate, polyphenylene oxide , Polyurethane, polyethylene terephthalate (may be abbreviated as “PET”), polybutadiene terephthalate, simple substance such as nylon, or mixture (co-extruded film, etc.), and laminator It can be mentioned Hinto.

  The thickness of the base portion 14 (thickness of the portion of the lenticular lens layer 13 excluding the lenticular lens portion 15; that is, the thickness of the thinnest portion of the lenticular lens layer 13) is not particularly limited, but is usually 30 μm or more. It is 200 micrometers or less, and about 30 micrometers is preferable.

  Further, the base 14 has a different form depending on the material to be used, and is not particularly limited. However, it is preferable to use PET, and its refractive index is about 1.60.

  The lenticular lens portion 15 is disposed on the light source side of the base portion 14. A plurality of unit lenses 16 having a convex side on the light source side and a longitudinal direction in the vertical direction are juxtaposed in the horizontal direction. The unit lens 16 can be a normal lenticular lens. For example, the lenticular lens portion 15 can be formed by juxtaposing unit lenses 16 having a height (thickness) of about 20 μm to 100 μm at a pitch of about 50 μm to 250 μm.

A material capable of transmitting light is applied to the unit lens 16. For example, thermoplastic resins such as polyvinyl chloride, acrylic resins (PMMA, etc.), polystyrene, polycarbonate, unsaturated polyester, melamine, epoxy, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate And thermosetting resins such as polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, and triazine acrylate. Moreover, each can be used individually or in mixture of the said thermoplastic resin and thermosetting resin.
The refractive index of the unit lens 16 is preferably about 1.4 or more and 1.6 or less.

By providing the lenticular lens layer 13 having the above-described configuration, the image light that has been converged so as to be parallel or parallel to the observer side (front direction) through the full-lens lens sheet 21 as will be described later is lenticular. An image formed by the lens 15 and diffused in the parallel direction of the unit lenses 16 (horizontal direction in the present embodiment) to widen the viewing angle can be provided to the observer.

  The diffusion layer 17 is a layer formed along the surface of the lenticular lens unit 15. The light diffusion layer 17 is a layer having a function of diffusing transmitted light. Specifically, the light diffusion layer 17 has a base portion made of a transparent resin and a diffusion component dispersed in the base portion. The light diffusion layer 17 can diffuse light due to a difference in refractive index between the base portion and the diffusion component, or due to the reflectivity of the diffusion component itself. With this function of the light diffusion layer 17, the image light is diffused and a predetermined viewing angle can be obtained.

As the transparent resin forming the base portion of the light diffusion layer 17, for example, methyl methacrylate / butadiene / styrene copolymer (MBS), acrylic resin, polycarbonate resin, or the like can be used.
On the other hand, as the diffusing component, organic fillers such as plastic beads are preferable, and those having high transparency are particularly preferable. Examples of the plastic beads include melamine beads, acrylic beads, acrylic-styrene beads, polycarbonate beads, polyethylene beads, polystyrene beads, and vinyl chloride beads. Among these, acrylic beads are preferable. In addition, the diffusion component can be composed of bubbles.

  The thickness of the light diffusion layer 17 is preferably from 0.1 mm to 2.0 mm, and more preferably from 0.2 mm to 1.5 mm. If the thickness of the light diffusion layer 17 is less than 0.1 mm, there is a possibility that the light diffusion effect cannot be obtained sufficiently. On the other hand, if the thickness of the light diffusion layer 17 exceeds 2.0 mm, the image may be blurred.

  Next, the Fresnel lens sheet 21 will be described. It is preferable that the Fresnel lens sheet 21 is disposed on the light incident surface side of the multilayer body 11 and is curved so as to be convex in the same direction as the multilayer body 11. The Fresnel lens sheet 21 includes a base portion 22 and a Fresnel lens portion 23 formed on the surface of the base portion 22. FIG. 4 schematically shows a form when the transmission screen 10 is viewed from the front in order to explain the Fresnel lens portion 23.

  The base portion 22 is a portion serving as a base for forming the Fresnel lens portion 23. Therefore, the base portion 22 has translucency and is configured to have such strength that the Fresnel lens portion 23 can be formed and held. Specific examples of the material constituting the base portion 22 include films of polycarbonate, cycloolefin, TAC (Triacetylcellulose), and the like. Among these, polycarbonate is preferable from the viewpoint of availability and cost. The polycarbonate used herein is one having polycarbonate as a main polymer, and may include, for example, a filler such as a deterioration inhibitor, a plasticizer, and a softener, or a composite with a methacrylic resin or the like.

  The thickness of the base portion 22 (the thickness of the portion excluding the Fresnel lens portion 23 of the Fresnel lens sheet 21. That is, the thickness of the thinnest portion of the Fresnel lens sheet 21) is preferably 1 mm or more and 2 mm or less. By setting the thickness of the base 22 to 1 mm or more, it becomes easy to impart sufficient rigidity to the Fresnel lens sheet 21. On the other hand, by setting the thickness of the base portion 22 to 2 mm or less, it is possible to prevent problems such as an excessive increase in the thickness of the transmissive screen 10, a decrease in image light transmittance, and a ghost (double image). It becomes easy to do.

  The Fresnel lens unit 23 has a function of deflecting the traveling direction of the image light projected from the image light source 3 onto the transmissive screen 10 as a divergent light beam. Specifically, the Fresnel lens unit 23 converts the image light incident as a divergent light beam into a parallel light beam traveling from the image light incident side toward the image light emitting side, for example, a parallel light beam traveling in the front direction. In this way, by using the Fresnel lens portion 23 to once convert the image light into a parallel light flux, it is possible to effectively reduce the inner surface variation in the brightness of the image observed by the observer, in particular, the image observed by the observer from an oblique direction. Can be relaxed.

As can be seen from FIG. 4, the Fresnel lens portion 23 of the present embodiment is a so-called circular Fresnel lens. Therefore, the longitudinal direction of each of the plurality of unit lenses 24 extends in an arc shape having a predetermined radius, and is arranged so as to form a concentric circle with the adjacent unit lenses 24. As the cross-sectional shape of each unit lens 24, a publicly known one can be used according to the purpose.
In the present embodiment, the unit lens 24 is symmetrical with respect to the vertical direction line A passing through the center position in the horizontal direction in the horizontal direction. On the other hand, with respect to the vertical direction, the center O of the concentric circle where the unit lenses 24 are arranged is below the transmission screen 10 on the vertical direction line A. In this way, by decentering the center O from the center of the Fresnel lens portion 23 in the vertical direction, even if image light is projected from below the transmission screen 10, the divergent light beam from the image light source 3 is efficiently converted into a parallel light beam. can do. Further, with the configuration in which the image light is irradiated from below the transmission screen in this way, the image light source 3 can be brought closer to the observer side, and the display device 1 can be made thin.

  However, the present invention is not limited to this, and a circular Fresnel lens in which the center of the concentric circle exists in the Fresnel lens portion or a plurality of unit lenses in a direction different from the direction in which the unit lens extends horizontally or vertically linearly. It does not preclude the application of a linear Fresnel lens in which is arranged.

As resin which comprises the Fresnel lens part 23, transparent resins, such as an acrylic resin, a styrene resin, a polyester resin, a polycarbonate resin, an acryl-styrene copolymer resin, can be mentioned.
When the size of the transmission screen 10 is large, epoxy acrylate or urethane acrylate reactive resin (ionizing radiation curable resin or the like) can be used from the viewpoint of moldability.

  The transmission screen 10 described above can be manufactured as follows, for example. The Fresnel lens sheet 21 can be produced by a known method. For example, the Fresnel lens sheet 21 can be produced by shaping the Fresnel lens part 23 on the base part 22. Moreover, the laminated body 11 can be produced as follows, for example. That is, the laminate 11 can be produced by forming the lenticular lens layer 13 and the diffusion layer 17 by coextrusion, and forming the hard coat layer 12 after bending as described later.

  Here, before the lenticular lens layer 13 and the diffusion layer 17 are overlapped with the Fresnel lens sheet 21, the lenticular lens layer 13, the diffusion layer 17 and the Fresnel lens sheet 21 are respectively curved in advance. The method for bending is not particularly limited. For example, each sheet may be heated to a temperature above the glass transition point to be softened, and then cooled according to a mold for bending the sheet. it can. At this time, since the lenticular lens layer 13 and the diffusion layer 17 and the Fresnel lens sheet 21 are simple in structure, they can be easily bent without being damaged, and can be easily bent greatly. After curving the lenticular lens layer 13 and the diffusion layer 17, the resin constituting the hard coat layer 12 is applied and cured by spraying or the like on the surface of the lenticular lens layer 13 opposite to the side where the diffusion layer 17 is formed. Thus, the hard coat layer 12 can be formed.

  A curved laminated body 11 is disposed on the Fresnel lens portion 23 side of the curved Fresnel lens sheet 21 formed as described above, and the outer edges of both are fixed with a frame or the like for positioning, and a transmissive screen having a curved surface 10 can be obtained.

  As described above, the transmission screen 10 can be easily manufactured without going through a complicated process. Further, since the transmissive screen 10 includes a curved portion, the transmissive screen 10 can have a good design.

  According to the display device 1 including the transmission screen 10 described above, it is possible to provide image light to an observer as follows, for example. An explanation will be given while showing an example of an optical path. However, the optical path examples shown here are conceptual and do not strictly represent reflection angles, refraction angles, or the like.

As shown in FIG. 1, the image light L <b> 1 emitted from the image light source 3 reaches the light incident surface side of the transmissive screen 10.
The image light reaching the light incident surface side of the transmissive screen 10 in this way is observed by the action of the Fresnel lens portion 23 of the Fresnel lens sheet 21 as indicated by the image lights L31 and L32 in FIGS. It is deflected so as to be parallel to the person side (front direction). FIG. 5 is a vertical sectional view of the transmissive screen 10.

  The image light deflected in the Fresnel lens sheet 21 is isotropically diffused in the diffusion layer 17 (the degree of diffusion in the diffusion layer 17 is smaller than that in the lenticular lens layer 13 and is not shown in the figure). ), And then reaches the lenticular lens layer 13. In the lenticular lens layer 13, as indicated by the image lights L31 and L32 in FIG. 3, the image light is emitted in a direction that widens the viewing angle in the horizontal direction with respect to the front surface.

  In the illustrated embodiment, since the unit lenses 16 of the lenticular lens unit 15 are arranged in parallel in the horizontal direction, the viewing angle in the horizontal direction can be widened by diffusing the image light in the horizontal direction as described above. If the unit lenses of the lenticular lens unit are arranged in parallel in the vertical direction, the viewing angle in the vertical direction can be widened by diffusing the image light in the vertical direction. As described above, the parallel direction of the unit lenses of the lenticular lens unit can be appropriately determined depending on the direction in which the viewing angle of the image is desired to be widened. In the lenticular lens unit 15, light is diffused in the parallel direction of the unit lenses 16 as described above. However, since light is diffused isotropically in the diffusion layer 17, according to the transmissive screen 10, the unit lens The viewing angle can be expanded to some extent in directions other than the 16 parallel directions.

  However, when the rear projection display device is mounted on an automobile, it is preferable that the unit lenses of the lenticular lens unit are arranged in parallel in the horizontal direction. The rear projection display device can be mounted on an automobile so that the light exit surface is visible from inside the vehicle. For example, a rear projection display device can be mounted on a dashboard of an automobile. At this time, if the image light of the rear projection display device is diffused in the vertical direction, there is a possibility of causing a problem such as reflection on the windshield. On the other hand, in order to view the image light of the rear projection display device mounted on the dashboard from the driver's seat or passenger seat, the image light of the rear projection display device is diffused in the horizontal direction and the viewing angle in the horizontal direction is widened. It is preferable. Therefore, when the rear projection display device is mounted on an automobile, it is preferable that the unit lenses of the lenticular lens unit are arranged in parallel in the horizontal direction.

1 Rear projection display device (display device)
DESCRIPTION OF SYMBOLS 2 Case 3 Video light source 10 Transmission type screen 11 Base material layer 12 Hard coat layer 13 Lenticular lens layer 14 Base 15 Lenticular lens part 16 Unit lens 17 Diffusion layer 21 Fresnel lens part 22 Base 23 Fresnel lens 24 Unit lens

Claims (6)

A transmission type screen having a laminated body in which a plurality of layers are laminated to transmit image light incident from the light incident surface side to the light exit surface side,
The laminate has a curved portion so as to be convex on one surface side,
The laminate is from the light exit surface side.
A transmissive screen comprising: a hard coat layer; a lenticular lens layer having a lenticular lens portion; and a diffusion layer that diffuses light formed along the surface of the lenticular lens portion.   The transmissive screen according to claim 1, further comprising a Fresnel lens sheet having a Fresnel lens portion on the light incident surface side of the laminate. The transmission screen according to claim 1 or 2,
A rear projection display device comprising: an image light source disposed on the light incident surface side of the transmissive screen.   The rear projection display device according to claim 3, wherein unit lenses constituting the lenticular lens unit are arranged in parallel in a horizontal direction.   The rear projection display device according to claim 3, wherein unit lenses constituting the lenticular lens unit are juxtaposed in the vertical direction. A rear projection display device according to claim 5,
An automobile in which the rear projection display device is arranged so that the light exit surface is visible from inside the vehicle.

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