JP2007156140A - Lenticular lens sheet and rear projection type screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lenticular lens sheet of high rigidity and good moldability, further, having a wide allowable range of optical axis deviation. <P>SOLUTION: The lenticular lens sheet 1 is arranged closest to the exit surface side in the rear projection type screen. Regarding the lenticular lens sheet 1, a vertical viewing angle formation lens 11 for vertically dispersing image light is provided on the incident surface side, and a horizontal viewing angle formation lens 12 for horizontally dispersing the image light is provided on the exit surface side. Preferably, the thickness of the sheet is set as ≥0.4mm and ≤2.0mm. Further, it is desirable to set the pitch of the vertical viewing angle formation lens 11 as ≤0.4mm, and the pitch of the horizontal viewing angle formation lens 12 as ≤0.4mm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lenticular lens sheet and a rear projection screen used in a rear projection display device.

  As the rear projection display device, an image display device and a rear projection screen are used. In general, Fresnel lens sheets and lenticular lens sheets are used for rear projection screens. Further, a front sheet may be provided on the emission side. In order to prevent a decrease in contrast due to external light reflection, an external light absorption layer is provided on the observation side of the lenticular lens sheet.

  Generally, a rear projection screen is designed such that the horizontal viewing angle is wider than the vertical viewing angle. Therefore, a general lenticular lens sheet includes a lenticular lens that diffuses image light in the horizontal direction so that the viewing angle in the horizontal direction is wide. In order to secure a viewing angle in the vertical direction, a light diffusing material that diffuses image light in the vertical direction is mixed in the lenticular lens sheet.

  In recent years, as a video display device, a micro display (MD) such as a liquid crystal (LCD) or a digital mirror device (DMD) is used in addition to a CRT type. In particular, these MD lenticular lenses are required to reduce the lens pitch to, for example, 0.3 mm or less. This is for high definition and for avoiding the moire problem caused by interference between the pixel and the lenticular lens. In a commercially available lenticular lens sheet, the lens pitch may even be 0.15 mm or less.

  A general light-transmitting resin (refractive index: 1.5 to 1.6) is used, a lens is provided only on the incident surface, an external light absorption layer pattern is provided on the exit surface side, and the pitch is 0.3 ( With a lenticular lens of 0.15) mm, when trying to achieve the required horizontal viewing half-value angle of about 30-40 °, the thickness is about 0.4 (0.2) mm. With this thickness, there are the following problems.

(1) Insufficient rigidity Insufficient strength makes handling difficult and causes problems such as damage. Moreover, since it cannot stand on its own, a front sheet is required on the emission side. Therefore, the number of parts increases, and the cost increases due to an increase in the steps of bonding and overlaying.

(2) Formability Although extrusion molding using a thermoplastic resin is frequently used for molding a screen sheet, it is difficult to produce a fine lens sheet having a thickness of 0.4 mm or less by an extrusion molding method. In particular, it is difficult to produce a lens sheet having a pattern such as a lens on both sides by an extrusion method. A so-called 2P molding method using an ultraviolet curable resin can mold a fine lens sheet having a thickness of 0.4 mm or less, but the cost is high because the resin material is expensive.

  On the other hand, Patent Document 1 discloses a technique for ensuring a certain thickness or more even if the lens pitch is about 0.3 mm by providing lenses on both the entrance surface and the exit surface.

  However, in the double-sided shaped lens sheet, it is necessary to match the optical axes of the entrance surface lens and the exit side lens. In the extrusion molding method, since the optical axis accuracy is about ± 5 μm, there arises a problem that the viewing angle becomes asymmetric due to the optical axis shift. Similar problems occur due to the optical axis accuracy in the 2P molding method.

  A so-called fly-eye lens sheet in which fine lenses that diffuse image light in the horizontal and vertical directions are two-dimensionally arranged is disclosed in Patent Document 2 and the like. However, it is difficult to manufacture a large-area mold having a fine curved surface shape, and it is difficult to manufacture efficiently.

  Furthermore, FIG. 12 of Patent Document 3 discloses a lens sheet that includes a lens that diffuses image light in the vertical direction on the incident surface and a lens that diffuses image light in the horizontal direction on the output surface. However, in Patent Document 3, only the structure is illustrated, and the lens pitch, sheet thickness, and the like are not described.

Japanese Patent Laid-Open No. 9-80210 JP 2000-111708 A JP 7-168282 A

  As described above, according to the conventional lenticular lens sheet, there are problems such as rigidity, moldability, and optical axis misalignment.

  The present invention has been made to solve such a problem, and provides a lenticular lens sheet and a rear projection screen having high rigidity, good moldability, and a wide tolerance for optical axis misalignment. For the purpose.

  A lenticular lens sheet according to the present invention is a lenticular lens sheet provided on the most exit surface side in a rear projection screen, and is provided on the entrance surface side, and a vertical viewing angle forming lens that diffuses image light in the vertical direction; A horizontal viewing angle forming lens provided on the exit surface side for diffusing video light in the horizontal direction, and depending on the distance between the vertex of the vertical viewing angle forming lens and the vertex of the horizontal viewing angle forming lens The represented sheet thickness is 0.4 mm or more and 2.0 mm or less, the pitch of the vertical viewing angle forming lens is 0.4 mm or less, and the pitch of the horizontal viewing angle forming lens is 0.4 mm or less. .

  Here, the sheet thickness is preferably 0.4 mm or more and 1.4 mm or less. The lens pitch of the vertical viewing angle forming lens is preferably 0.3 mm or less. Furthermore, the lens pitch of the horizontal viewing angle forming lens may be 0.3 mm or less.

  Further, an external light absorption layer may be provided in the non-transmission portion of the image light on the exit surface side, and the ratio of the external light absorption layer to the exit surface may be 50% or more. Further, a diffusion layer may be provided inside the lenticular lens sheet.

  The rear projection screen according to the present invention is a Fresnel lens sheet in which the above-described lenticular lens sheet and a horizontal viewing angle forming lens that diffuses image light in the horizontal direction are formed on the incident surface, and a Fresnel lens is formed on the output surface. And the lenticular lens sheet is disposed on the exit surface side of the Fresnel lens sheet.

  According to the present invention, it is possible to provide a lenticular lens sheet and a rear projection screen having high rigidity, good moldability, and a wide tolerance for optical axis deviation.

Embodiment 1 of the Invention
FIG. 1 is a perspective view showing a configuration of a part of the lenticular lens sheet according to the first embodiment of the present invention. The lenticular lens sheet 1 is used together with the Fresnel lens sheet as a component constituting a rear projection screen in a rear projection display device, but has a high rigidity and does not require a front plate. Therefore, in the rear projection screen, the lenticular lens sheet 1 is located closest to the exit surface (observer) side.

  As shown in FIG. 1, in the lenticular lens sheet 1 according to the first embodiment, a convex vertical viewing angle forming lens (VL) 11 is formed on the incident surface on which the image light 100 is incident, and the exit surface is formed. Are provided with a horizontal viewing angle forming lens (HL) 12 and an external light absorber 13. An external light absorption layer 131 is formed on the top of the external light absorption unit 13.

  The vertical viewing angle forming lens 11 includes a cylindrical lens that diffuses the image light 100 in the vertical direction. The cylindrical lens constituting the vertical viewing angle forming lens 11 collects the image light 100 in the vicinity of the lens surface of the horizontal viewing angle forming lens 12 and then diffuses it. That is, the focal point of the vertical viewing angle forming lens 11 is in the vicinity of the lens surface of the horizontal viewing angle forming lens 12. The cylindrical lenses are arranged in parallel to each other so that the longitudinal direction thereof is horizontal when the lenticular lens sheet 1 is fixed to the rear projection display device.

  The focal position of the vertical viewing angle forming lens 11 is preferably near the top of the external light absorber 13. This is because the light collected by the vertical viewing angle forming lens 11 is not easily lost by the external light absorption layer 131 provided on the top of the external light absorption unit 13.

  The vertical viewing angle forming lens 11 is preferably substantially elliptical, and its focal position is preferably in the range of 20% of the sheet thickness on the exit side from the vicinity of the top of the external light absorber 13. This is because the exit window can be narrowed and the area ratio of the external light absorption layer 131, that is, the BS ratio can be increased.

  The lens of the lenticular lens sheet 1 according to the first embodiment has high definition. More specifically, the pitch VLp of the vertical viewing angle forming lens 11 according to the first embodiment is preferably VLp ≦ 0.4 mm, and more preferably VLp ≦ 0.3 mm. The pitch HLp of the horizontal viewing angle forming lens 12 according to the first embodiment is preferably VLp or less, more specifically, HLp ≦ 0.4 mm, and more preferably HLp ≦ 0. .3 mm is preferable. When the pitch of the horizontal viewing angle forming lenses 12 is too large, a problem that the image light passing through the valley portions of the lenses is blocked by the convex external light absorber 13 is likely to occur. Furthermore, in the MD screen, small brightness unevenness of grains, so-called “glare” is a problem to be solved. From the viewpoint of reducing this “glare” and preventing resolution reduction, the smaller pitch is required. Is preferred.

  The horizontal viewing angle forming lens 12 is constituted by a cylindrical lens that diffuses the image light 100 in the horizontal direction. Such cylindrical lenses are arranged in parallel to each other so that the longitudinal direction thereof is vertical when the lenticular lens sheet 1 is fixed to the rear projection display device. The horizontal viewing angle forming lens 12 does not have to take into account the squeezing caused by the external light absorption layer or the like, and therefore does not have to be one-point condensing. The horizontal viewing angle forming lens 12 may be trapezoidal.

  In the lenticular lens sheet 1 according to the first embodiment, a vertical viewing angle forming lens 11 is provided on the entrance surface, and a horizontal viewing angle forming lens 12 is provided on the exit surface. As described above, the focal point of the vertical viewing angle forming lens 11 is required to be in the vicinity of the lens surface of the horizontal viewing angle forming lens 12. However, in the rear projection display device, the vertical viewing angle is higher than the horizontal viewing angle. Since the distance to the focal point can be made relatively long, the sheet thickness can be increased compared to the case where the horizontal viewing angle forming lens is formed on the incident surface of the lenticular lens sheet 1. Can do. In the embodiment of the present invention, the thickness of the sheet refers to the distance between the tops of the lens 11 provided on the entrance surface and the lens 12 provided on the exit surface.

  Specifically, the thickness T of the lenticular lens sheet 1 according to the first embodiment is preferably not less than 0.4 mm and not more than 2.0 mm, and more preferably not less than 0.4 mm and not more than 1.4 mm. By having such a thickness, rigidity can be increased, handling can be facilitated, and occurrence of problems such as damage can be suppressed. Furthermore, since it has such a thickness, it can be self-supporting, and it is not necessary to provide a front sheet on the light exit side, so that cost reduction can be achieved.

  In the lenticular lens 1 according to the first embodiment, the preferable viewing angle range of the vertical viewing angle forming lens 11 is αv (vertical luminance 1/2 angle) = 8 to 15 °, βv (vertical luminance 1/3 angle). = 10-20 °, γv (vertical luminance 1/10 angle) = 15-30 °, and the viewing angle range of the horizontal viewing angle forming lens 12 is αh (horizontal luminance 1/2 angle) = 25-40 °, βh (horizontal luminance 1/3 angle) = 30 to 45 ° and γh (horizontal luminance 1/10 angle) = 40 to 60 °. Thereby, a practical viewing angle can be ensured.

In order to satisfy such a viewing angle, the vertical viewing angle forming lens 11 preferably has a shape specified by the following expression.
C = 1 / {f · (1-n1 / n2)}
K = − {(n1 / n2) ² }
C: Lens curvature
K: Conic constant of the lens
f: Focal length (mm) (≈ distance between lens tops)
n1: Air refractive index (= 1)
n2: Refractive index of the substrate of the vertical viewing angle forming lens 11 (= about 1.5 to 1.6)

  The preferred diffusibility of the Fresnel lens sheet used on the incident surface side of the lenticular lens 1 according to the first embodiment is that the vertical diffusion viewing angle range is αv = 0 to 2.5 ° and βv = 0 to 2.7. °, γv = 0 to 3.5 °, and the horizontal diffusion viewing angle range is αh = 4.8 to 11.5 °, βh = 5.3 to 12.6 °, γh = 6.4 to 15 .4 °. This is because the light diffused by the Fresnel lens sheet is not easily scattered by the external light absorbing portion 13 of the lenticular lens 1 and has the effect of reducing the “glare” described above.

  The external light absorbing portion 13 is provided in a non-light condensing portion where the light from the vertical viewing angle forming lens 11 does not condense, and is formed so as to protrude from the emission surface in a convex shape. A flat surface parallel to the main surface of the lenticular lens sheet 1 is formed at the top of the external light absorbing portion 13. An external light absorption layer 131 is formed on the top of the external light absorption unit 13. The external light absorption layer 131 is formed by means such as roll printing, screen printing, transfer printing, and the like, and is composed of a black paint or the like. As shown in FIG. 1, the external light absorber 13 is convex and preferably higher than the apex of the horizontal viewing angle forming lens 12. This is because low-cost roll printing and screen printing can be applied.

  The external light absorbing layer 131 may be formed by a so-called self-alignment method. Specifically, a film coated with a light-shielding photocurable resin is bonded to the exit surface of the lenticular lens sheet 1. Then, ultraviolet rays are irradiated from the incident surface of the lenticular lens sheet 1. If it does so, the light-shielding photocurable resin of the condensing part of an ultraviolet-ray will be hardened. The light-shielding photocurable resin in the ultraviolet non-condensing part remains uncured on the exit surface. When the film is peeled off, the light-shielding photocurable resin in the ultraviolet condensing part is fixed to the film and peeled off. Next, the uncured light-blocking light-curing resin of the non-light-collecting portion is cured by irradiation with radiation from the exit surface side of the lenticular lens sheet 1. Thereby, the external light absorption layer 131 is formed.

  The external light absorbing layer 131 is composed of a plurality of stripes parallel to each other so that the longitudinal direction thereof is horizontal when the lenticular lens sheet 1 is fixed to the rear projection display device. The area ratio of the external light absorption layer 131 to the entire emission surface of the lenticular lens sheet according to the present embodiment, that is, the BS ratio is preferably 50% or more, and more preferably 60% or more. As a result, the contrast can be increased.

  FIG. 2 shows a sectional view of a rear projection screen including the lenticular lens sheet 1 according to the present embodiment. A Fresnel lens sheet 2 is provided on the incident surface side of the lenticular lens sheet 1. The thickness of the Fresnel lens sheet 2 is, for example, not less than 1.5 mm and not more than 2.5 mm.

  Multiple rows of cylindrical lenses 21 may be provided on the incident surface of the Fresnel lens sheet 2. The cylindrical lens 21 diffuses the incident video light 100 in the horizontal direction. The cylindrical lenses 21 are arranged in parallel to each other so that the longitudinal direction thereof is vertical in a state where the Fresnel lens sheet 2 is fixed to the rear projection display device. The lens pitch of the cylindrical lens 12 is, for example, 30 μm or more and 50 μm or less, and is preferably shorter than the lens pitch formed on the lenticular lens sheet 1.

  A Fresnel lens 22 is formed on the exit surface of the Fresnel lens sheet 2. The Fresnel lens 22 converts the incident image light 100 into parallel light or focused light.

  A diffusion layer 14 made of a diffusion material is provided in the lenticular lens sheet 11, that is, in a region separated from the incident surface and the emission surface by a predetermined distance inside. It is preferable that the diffusion layer 14 is disposed closer to the emission surface side. Moreover, the refractive index difference Δn between the base material of the diffusion layer 14 and the diffusion material is −0.04 to −0.01 or +0.01 to +0.04, the average particle diameter φ of the diffusion material is 3 to 20 μm, and the concentration is It is desirable that the thickness is 2 to 20% by weight and the thickness of the diffusion layer is 0.1 to 1.0 mm. In particular, Δn is preferably +0.02 to 0.03, φ is 5 to 10 μm, the concentration is 5 to 10% by weight, and the thickness of the diffusion layer is preferably 0.2 to 0.4 mm.

  As shown in FIG. 3, in the lenticular lens sheet according to the first embodiment, the optical axis of the vertical viewing angle forming lens 11 provided on the incident surface is the light absorbing portion 13 provided on the exit surface. Although it is desirable to be located at the center between the two, an optical axis deviation Δx may occur between them. In the present invention, since the horizontal viewing angle forming lens 12 having the same shape in the vertical direction is provided in the region where the image light is transmitted on the exit surface, the tolerance for the optical axis deviation is wide. More specifically, no problem occurs if Δx is ± 5 μm or less.

  Regarding the mold for manufacturing the lenticular lens sheet 1 having the above-described configuration, the entrance surface mold can be manufactured by cutting the vertical viewing angle forming lens 11 in the circumferential direction of the roll mold. The exit surface mold can be manufactured by cutting the external light absorbing portion 13 in the circumferential direction and then cutting the horizontal viewing angle forming lens 12 in the roll axis direction. Considering burrs and deformation of the mold, it is preferable to cut the external light absorbing portion 13 before cutting the horizontal viewing angle forming lens 12 as described above, but it may be performed later. The lenticular lens sheet 1 is preferably formed by low cost extrusion molding.

Embodiment 2 of the Invention
In the lenticular lens sheet according to the first embodiment of the invention, the rectangular external light absorbing portion 13 is provided separately from the horizontal viewing angle forming lens 12. However, in the second embodiment of the present invention, the horizontal viewing angle forming lens is formed. The external light absorption part 13 was formed by directly forming the external light absorption layer 131 on the lens 12.

  FIG. 4 shows a schematic cross-sectional view of the lenticular lens sheet according to the second embodiment. As shown in the figure, a plurality of cylindrical lenses constituting the horizontal viewing angle forming lens 12 are formed on the exit surface of the lenticular lens sheet 1, and roll printing, screen printing, transfer printing, etc. are directly formed thereon. By this means, the black paint is applied, and the external light absorption layer 131 is formed. The external light absorbing layer 131 may be formed by a so-called self-alignment method.

  In the lenticular lens sheet having such a configuration, the lens pitch, the sheet thickness, and the lens shape described in the first embodiment of the invention provide high rigidity, good moldability, and further against optical axis misalignment. The allowable range can be widened.

Example 1.
As Example 1, a lenticular lens sheet having a shape as shown in FIG. 1 was produced by an extrusion molding method. The sheet substrate is a methacryl-styrene copolymer resin, and its refractive index is 1.54. In the lenticular lens according to Example 1, the lens pitch VLp of the vertical viewing angle forming lens 11 is 0.265 mm, the lens pitch HLp of the horizontal viewing angle forming lens 12 is 0.265 mm, and the sheet thickness T is 1.2 mm. . An outside light absorbing portion 13 is provided in a place other than the light transmitting portion on the emission surface, and an outside light absorbing layer 131 is formed on the surface thereof. The area ratio of the external light absorption layer 131 is 65%.

Further, the lens shape of the vertical viewing angle forming lens 11 is expressed by the following equation, where X is a vertical distance from the top of the vertical viewing angle forming lens and Y is a height from the top of the vertical viewing angle forming lens. be able to. In the formula, the unit is mm. The range of X is -0.1325 to +0.1325 mm.
Y = C * X ² / (1+ (1- (K + 1) * C ² * X ² ) ^1/2 )
C = 2.38551645E + 00
K = -4.2330390E-01

  Regarding the lens shape of the horizontal viewing angle forming lens 12, X is a horizontal distance from the top of the horizontal viewing angle forming lens, and Y is the height from the top of the horizontal viewing angle forming lens (from the exit surface to the entrance surface). If the direction to is a positive direction), it can be expressed by the following formulas A and B. In formulas A and B, the unit is mm.

First, Formula A defines Y in the range of X = −0.0239 to +0.0239 mm at the center of the lens, and indicates that the emission part has a flat shape within this range.
Next, Formula B defines lens shapes in the range of X = −0.1325 to −0.0239 mm and X = + 0.0239 to +0.1325 mm at the lens end.
Y = 0 (A)
However, the range of X = −0.0239 to +0.0239 mm Y = C * X ² / (1+ (1- (K + 1) * C ² * X ² ) ^1/2 ) (B)
+ D * | X | + E * | X | ² + F * | X | ³ + G * | X | ⁴
+ H * | X | ⁵ + J * | X | ⁶ + L * | X | ⁷ + M * | X | ⁸
+ N * | X | ⁹ + P * | X | ¹⁰
However, the range of X = −0.1325 to −0.0239 mm and X = + 0.0239 to +0.1325 mm C = 0.0000000E + 00
K = 0.0000000E + 00
D = -1.8321193E + 00
E = 2.6398851E + 02
F = -1.7257676E + 04
G = 6.55584936E + 05
H = −1.5360156E + 07
J = 2.27996912E + 08
L = −2.1448485E + 09
M = 1.384420E + 10
N = -4.0020886E + 10
P = 5.5419163E + 10
Here, | X | indicates the absolute value of the variable X. mE + n represents m × 10 ⁿ .

  In addition, the diffusion layer is disposed on the outermost surface side, and contains a diffusion material having a refractive index of 1.54 and a diffusion material having Δn of 0.02 and φ of 8 μm at a concentration of 8%. 0.2 mm.

  With the above lenticular lens sheet, the viewing angle is αh in combination with Fresnel αv≈βv≈γv≈0 °, αh = 9.6 °, βh = 10.5 °, γh = 12.8 °. = 28 °, βh = 34 °, γh = 46 °, αv = 12.0 °, βv = 15.0 °, γv = 22.2 °.

  According to this embodiment, a lenticular lens sheet having a wide viewing angle, high rigidity, and excellent contrast can be provided.

  In this case, there is no problem even if the optical axis deviation between the vertical viewing angle forming lens 11 and the external light absorbing layer, that is, the opening is about 20 μm.

Example 2
As Example 2, a lenticular lens sheet having a shape as shown in FIG. 1 was produced by a 2P molding method. A PET (polyethylene terephthalate) film was used as a base sheet, and a lens and a light absorbing part were molded with an ultraviolet curable resin on both sides thereof. The refractive index of the ultraviolet curable resin is 1.54.

  In the lenticular lens according to Example 2, the lens pitch VLp of the vertical viewing angle forming lens 11 is 0.150 mm, the lens pitch HLp of the horizontal viewing angle forming lens 12 is 0.080 mm, and the sheet thickness T = 0.680 mm. . An outside light absorbing portion 13 is provided in a place other than the light transmitting portion on the emission surface, and an outside light absorbing layer 131 is formed on the surface thereof. The area ratio of the external light absorption layer 131 is 65%.

Further, the lens shape of the vertical viewing angle forming lens 11 is expressed by the following equation, where X is a vertical distance from the top of the vertical viewing angle forming lens and Y is a height from the top of the vertical viewing angle forming lens. be able to. In the formula, the unit is mm. The range of X is -0.075 to +0.075 mm.
Y = C * X ² / (1+ (1- (K + 1) * C ² * X ² ) ^1/2 )
C = 4.2137906E + 00
K = -4.2330390E-01

Regarding the lens shape of the horizontal viewing angle forming lens 12, X is a horizontal distance from the top of the horizontal viewing angle forming lens, and Y is the height from the top of the horizontal viewing angle forming lens (from the exit surface to the entrance surface). The direction to is the positive direction). First, the range of X = −0.0095 to +0.0095 mm at the center of the lens is a flat shape, and Y = 0. Further, the ranges of X = −0.0400 to −0.0095 mm and X = + 0.0095 to +0.0400 mm at the lens end are inclined flat shapes. The inclined flat shape can be expressed by the following equation.
Y = D * | X | + Q
Where X = −0.0400 to −0.0095 mm and X = + 0.0095 to +0.0400 mm
D = 6.668415E-01
Q = −6.3499724E-03
Here, | X | indicates the absolute value of the variable X. mE + n represents m × 10 ⁿ .
In addition, the diffusion layer is disposed on the outermost surface side, and contains a diffusion material having a refractive index of 1.54 and a diffusion material having Δn of 0.02 and φ of 8 μm at a concentration of 8%. 0.2 mm.

  At this time, the viewing angles are αh = 34 °, βh = 39 °, γh = 48 in combination with Fresnel of αv≈βv≈γv≈0 °, αh = 10 °, βh = 11 °, γh = 13 °. °, αv = 12 °, βv = 15 °, and γv = 22 °.

It is a perspective view which shows the structure of a part of lenticular lens sheet concerning embodiment of this invention. It is sectional drawing of the rear projection type screen containing the lenticular lens sheet | seat 1 concerning this Embodiment. It is explanatory drawing which shows a cross section of the lenticular lens sheet concerning embodiment of this invention. It is explanatory drawing which shows a cross section of the lenticular lens sheet concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lenticular lens sheet 2 Fresnel lens sheet 11 Vertical viewing angle formation lens 12 Horizontal viewing angle formation lens 13 External light absorption part 131 External light absorption layer

Claims (7)

A lenticular lens sheet provided on the most exit surface side in the rear projection screen,
A vertical viewing angle forming lens that is provided on the incident surface side and diffuses image light in the vertical direction;
A horizontal viewing angle forming lens that is provided on the exit surface side and diffuses image light in the horizontal direction;
The sheet thickness represented by the distance between the vertex of the vertical viewing angle forming lens and the vertex of the horizontal viewing angle forming lens is 0.4 mm or more and 2.0 mm or less,
The vertical viewing angle forming lens pitch is 0.4 mm or less,
A lenticular lens sheet in which a pitch of the horizontal viewing angle forming lens is 0.4 mm or less.   The lenticular lens sheet according to claim 1, wherein the sheet thickness is 0.4 mm or more and 1.4 mm or less.   The lenticular lens sheet according to claim 1 or 2, wherein a lens pitch of the vertical viewing angle forming lens is 0.3 mm or less.   4. The lenticular lens sheet according to claim 1, wherein a lens pitch of the horizontal viewing angle forming lens is 0.3 mm or less. An external light absorption layer is provided in the non-transmission part of the image light on the exit surface side,
The lenticular lens sheet according to any one of claims 1 to 4, wherein a ratio of the external light absorption layer to the emission surface is 50% or more.   The lenticular lens sheet according to claim 1, wherein a diffusion layer is provided inside the lenticular lens sheet. The lenticular lens sheet according to any one of claims 1 to 6,
A lens for forming a horizontal viewing angle that diffuses image light in the horizontal direction is formed on the incident surface, and a Fresnel lens sheet having a Fresnel lens formed on the output surface is provided, and the lenticular lens sheet is disposed on the output surface side of the Fresnel lens sheet. Arranged rear projection screen.

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