JP2000112036A - Lenticular lens sheet and transmission type screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the contrast by suppressing the reflection of external light without deteriorating the intensity of video light so much and also to reduce the thickness of a system. SOLUTION: This lens sheet 10A is provided with a base material layer 15. A light entering side lens part 12 which is formed in a projected state on the side of the light entering surface 11 of the base material layer 15 and at which many unit lens elements having a condensing property such as lenticular lenses are arrayed, is provided. A colored layer 13 is formed at least in the vicinity of the light entering surface of the light entering side lens part 12. Also, a light absorbing layer 19 or the like is formed at a projected part provided at the non-condensing part of the light entering side lens part 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lenticular lens sheet and a transmission screen suitable for projecting and observing an image from an image light source.

[0002]

2. Description of the Related Art Conventionally, a rear projection type projection television (rear projection display system) using three CRTs of red, green and blue as an image light source and using a transmissive projection screen as a screen has been known. I have.
Such a transmission type projection screen is required to diffuse light to a wide range and to reduce the influence of external light.

FIG. 6 is a view showing an example of a lenticular lens sheet used for a conventional transmission type projection screen. A transmissive projection screen is used in combination with a Fresnel lens sheet that makes projection light substantially parallel light and a lenticular lens sheet that diffuses light to form an image. In order to satisfy the above-mentioned requirements, the transmission type projection screen is formed on a light incident surface 41 and is provided on a light incident side lens portion 42 such as a lenticular lens for condensing light, and on a light exit surface 44 side, and has a light incident surface. The light emitting side lens portion 47 formed near the light condensing point of the side lens portion 42 and the light absorbing layer (black stripe: black stripe) formed on the convex portion 48 provided at the non-light converging portion of the light incoming side lens portion 42 A lenticular lens sheet 40 with a BS that diffuses light and reduces the influence of external light at the same time is used.

Further, a projection television using a cell light source such as an LCD (Liquid Crystal Display) or a DMD (Digital Micro-mirror Device) has been developed as an image light source. Also in this projection television, the lenticular lens sheet with BS described above is used from the viewpoint of improving diffusion characteristics and preventing reflection of external light. With this lenticular lens sheet, in order to improve the contrast of the image,
It is effective to increase the BS rate.

[0005]

However, the above-mentioned conventional transmission screen has a projection tube (CR) in which images are separated into three colors.
T), etc., are projected onto the screen, and the angle between each projection tube (concentration angle) to reduce the thickness of the system
However, it has been difficult to increase the BS rate any more under the current situation where it is increasing year by year.

In the lenticular lens sheet described above, light is diffused only in the horizontal direction due to the lens shape, so that light diffusing fine particles (diffusing agent) are mixed into the sheet in order to diffuse light in the vertical direction. Was. The projection light and the external light incident from the light exit surface become stray light in the lenticular lens sheet due to the light diffusing fine particles, causing a reduction in contrast. In order to suppress the decrease in contrast, the entire lenticular lens sheet was lightly colored (body coloring). However, the effect of improving the contrast was small, although the transmittance was reduced.

An object of the present invention is to provide a lenticular lens sheet and a transmission screen which can suppress reflection of external light and increase contrast without significantly lowering the intensity of image light, and which can make the system thinner. To provide.

[0008]

According to a first aspect of the present invention, there is provided a base material layer having a light-collecting property formed in a convex shape on a light incident surface side of the base material layer. A light incident side lens portion in which a number of unit lens elements are arranged, a colored layer formed at least near a light incident surface of the light incident side lens portion, and a light exit surface side of the base material layer, A lenticular lens sheet comprising: a light absorbing layer formed on a non-light-collecting portion of the side lens portion.

According to a second aspect of the present invention, there is provided a light-entering side lens unit having a plurality of light-collecting unit lens elements arranged in a convex shape on the light-entering surface side of the substrate layer. A colored layer formed at least in the vicinity of the light incident surface of the light incident side lens portion;
A light-emitting side lens portion formed on the light-emitting surface side of the base material layer and near a light-collecting portion of the light-entering lens portion; and a light-emitting side lens on the light emitting surface side of the base material layer. A lenticular lens sheet comprising: a light absorbing layer formed in a non-light collecting portion of the portion.

According to a third aspect of the present invention, there is provided the lenticular lens sheet according to the second aspect, wherein the light emitting side lens portion has a convex or concave shape on the light emitting surface side.

[0011] The invention of claim 4 is the invention of claim 1 or claim 2.
3. The lenticular lens sheet according to claim 1, wherein a diffusing agent is added to at least the coloring layer.

The invention of claim 5 is the invention of claims 1 to 4.
A lenticular lens sheet according to any one of the above, and a Fresnel lens sheet disposed on a light source side of the lenticular lens sheet.

According to a sixth aspect of the present invention, there is provided the transmission screen according to the fifth aspect, further comprising: a front plate disposed on an observation side of the lenticular lens sheet;
A transmissive screen characterized by being colored near the light entrance surface, near the light exit surface, or as a whole.

According to a seventh aspect of the present invention, in the transmissive screen according to the fifth aspect, the lenticular lens sheet is characterized in that the vicinity of the light exit surface is colored.

[0015] The colored layer may be characterized in that its thickness is not less than 0.05 of the pitch of the lenticular lens shape. The colored layer may be characterized in that its thickness is not more than の of the sheet thickness. The colored layer has a thickness at the center of each of the lens portions t.
_1, the thickness as measured perpendicular to the lens surface of the skirt when the t _2, so that the t _1> t _2, can be characterized in that defines its thickness. When the concentration of the diffusing agent mixed in the colored layer is C ₁ and the concentration of the diffusing agent mixed in the base layer is C ₀ , 0 ≦ C ₀ <C ₁ holds. it can. The coloring layer is not mixed with a diffusing agent, the base layer is not colored or is colored thinner than the coloring layer, and further, between the coloring layer and the base layer. A diffusion layer formed and mixed with a diffusion agent may be provided.

[0016] The lenticular lens shape may be characterized in that the lenticular lens includes a portion whose tangent is at an angle greater than a critical angle with respect to the lenticular lens sheet surface. The light emitting side lens portion is characterized in that at least one of an antireflection layer, a low reflection layer, a polarizing filter layer, an antistatic layer, an antiglare treatment layer, and a hard code treatment layer is formed on a surface thereof. be able to.

The front plate has an anti-reflection layer on its light exit surface,
At least one of a low reflection layer, a polarizing filter layer, an antistatic layer, an antiglare treatment layer, and a hard coat treatment layer may be formed. The transmission screen may have a total light transmittance of 40 to 70%.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The present invention will be described in more detail with reference to an embodiment. (Embodiment of Transmission Screen) FIG. 1 is a view showing an embodiment of a transmission screen according to the present invention. This transmissive screen 1 is a combination of a lenticular lens sheet 10 and a Fresnel lens sheet 20 shown in FIG. 2 to be described later, together with a light source (not shown) using three CRTs of red, green and blue. , Constituting a rear projection system. The transmissive screen 1 has a configuration in which a lenticular lens 10 and a Fresnel lens sheet 20 (or a film Fresnel lens sheet) in which a Fresnel lens 21 is formed on the light exit side are used for uniformity of image brightness. Is preferred to increase the

(First Embodiment of Lenticular Lens Sheet) FIG. 2 is a view showing a first embodiment of a lenticular lens sheet according to the present invention and a first function of a colored layer. The lenticular lens sheet 10 includes a base layer 15 and a light-receiving side on which a number of light-collecting unit lens elements such as lenticular lenses are arranged in a convex shape on the light-entering surface 11 side of the base layer 15. The lens portion 12, the colored layer 13 formed at least near the light incident surface of the light incident side lens portion 12, and the light emitting surface 14 side of the base material layer 15 near the light condensing portion of the light incident side lens portion 12. Outgoing side lens part 1 formed in
7 and a light absorbing layer 19 formed on a convex portion 18 provided at a non-light collecting portion of the light incident side lens portion 12.
Here, the base material layer 15 is a layer from the coloring layer 13 to the light emitting surface 14. The colored layer 13 has a function of increasing contrast even though it is a lenticular lens sheet 10 having one side of light.

(Second Embodiment of Lenticular Lens Sheet) FIG. 3 is a view showing a second embodiment of a lenticular lens sheet according to the present invention and a first function of a colored layer. The lenticular lens sheet 10 </ b> A has a light incident side on which a plurality of light-collecting unit lens elements such as a lenticular lens, which are formed in a convex shape on the light incident surface 11 side of the substrate layer 15, are arranged. The lens unit 12 includes a colored layer 13 formed at least in the vicinity of a light incident surface of the light incident side lens unit 12, a light absorbing layer 19 formed on a non-light collecting part of the light incident side lens unit 12, and the like. ing. The colored layer 13 has a function of increasing contrast even though it is a lenticular lens sheet 10 having one side of light.

(Third Embodiment of Lenticular Lens Sheet) FIG. 4 is a view showing a third embodiment of a lenticular lens sheet according to the present invention and a first function of a colored layer. In the lenticular lens sheet 10B, the light-emitting side lens portion 17B has a concave shape. When the light-emitting side lens portion 17B has a concave shape, it does not have a function of correcting the convergence angle, and is used in a projection system having a single tube light source such as an LCD. At this time, it is also difficult to increase the BS ratio in order to increase the diffusion angle and the plate thickness. Therefore, the lenticular lens sheet 10B of this embodiment
As described above, by forming the colored layer 13 along the light incident side lens portion 12 as described above, it is possible to prevent a decrease in contrast due to external light.

(First Function of Colored Layer) The first function of the colored layer is to efficiently remove external light and improve contrast. As shown in FIG. 6, in the case of the lenticular lens sheet 40 with the BS, about half of the external light E vertically incident from the observation side is absorbed by the BS 49, and the outside light E enters the sheet from the light emitting side lens unit 47. The incident light,
To escape to the light source side without total reflection,
External light E has not been considered as a factor that lowers the contrast. However, the ambient light is incident from all angles, and some light enters the light exit side lens unit 17 at an angle. As shown in FIGS. 2 to 4, the external light B obliquely incident becomes light B <b> 1 and B <b> 2 emitted from the adjacent light exit side lens unit 17 after being totally reflected by the light entrance side lens unit 12. . As shown in FIGS. 2 to 4, the totally reflected light is transmitted a plurality of times (2 to 3) along the shape of the light incident side lens unit 12.
After repeating the total reflection, the colored layer 13 is formed along the shape of the light incident side lens portion 12 of the light incident surface 11 in order to emit light after the total reflection, whereby the light can be efficiently removed.

Next, the fact that the lenticular lens sheets 10, 10A and 10B according to the respective embodiments can obtain good contrast will be described in comparison with a lenticular lens sheet (body coloring type) 60 as a comparative example. The first function of the light incident surface coloring layer of the lenticular lens sheet according to each embodiment will be described with reference to FIGS. FIG. 5 is an explanatory diagram showing a lenticular lens sheet (body coloring type) according to a comparative example.

Lenticular lens sheet 60 of comparative example
Is a double-sided lenticular lens sheet of a body coloring type in which the base layer 65 is entirely colored. The external light D incident from the observation side is totally reflected by the lens portion 62 formed on the light incident surface 61, and the external light D is incident on the observation side.
1 and D2 are emitted again. At this time, the external light D is repeatedly reflected along the lenticular lens shape of the lens unit 62.

In the lenticular lens sheets 10, 10A, and 10B of the present embodiment, since the coloring layer 13 is formed along the path of the total reflection light, the coloring layer 13 of the image light is formed.
The optical path length of the external light B in the colored layer 13 is 5 to 10 times the internal optical path length. On the other hand, in the case of the lenticular lens sheet 60 of the body coloring type, the ratio is only about 2 to 3 times at most. For this purpose, the lenticular lens sheets 10, 10A, 10B of the present invention are used.
Since the reflection of the external light B can be suppressed without significantly lowering the intensity of the image light, a screen having good contrast can be obtained.

(Second Function of Colored Layer) The second function of the colored layer is to effectively remove stray light of image light. Second
The function of (1) is that a light emitting side lens portion is formed,
(2) The effect is more enhanced under the two conditions that the focal point of the light entrance side lens portion is substantially on the light exit surface.

As shown in FIG. 8, in the case of the conventional lenticular lens sheet 60 with BS, the image light C is
Light entrance side lens portion 62 of lenticular lens sheet 60
(C1) and the light exit side lens unit 64
(C3), a part (about 4%) of the energy of the light is reflected (C2, C4). The reflected light C4 becomes stray light, and the lenticular lens sheet 60
(C5, C6) after being reflected several times inside the image (C5), the light is again emitted from the observation side (C7), which causes a problem of lowering the contrast.

FIG. 7 is a view for explaining the second function of the colored layer of the lenticular lens sheet according to the first embodiment. Here, image light A incident at an inclination of θ = 10 °
[Usually, red (R) or blue (B) light has such an incident angle]. The image light A is condensed by the light incident side lens unit 12-1 on an inclined surface opposite to the incident side of the light exit side lens unit 17-1 (A1), and is condensed by the light exit side lens unit 17-1. The reflected light A4 is transmitted to the adjacent light entrance side lens unit 12-
Head to 2. After the total reflection is repeated by the adjacent light incident side lens unit 12-2 (A5, A6), the light is further emitted from the adjacent light exit side lens unit 17-3 (A7).

Here, with respect to vertically incident light, such as green (G) light, the condensing point of the light-entering lens portion 12 is usually a portion at the center of the light-emitting side lens portion 17 that is not inclined. Therefore, the light reflected by the light-emitting side lens unit 17 passes through the same light-entering side lens unit 12 as the incident light to the light source side. Therefore, as shown in FIG. 7, if the coloring layer 13 is formed along the lens surface of the light incident side lens portion 12, the coloring of the entire lenticular lens sheet as shown in FIG. This stray light can be effectively removed.

FIG. 9 is a view for explaining the second function of the colored layer of the lenticular lens sheet according to the third embodiment. The lenticular lens sheet 10B is a lens in which the light emitting side lens portion 17B has a concave shape. The lenticular lens sheet 10 </ b> B
Since B has no color correction effect, it is used for projection televisions with a single light source such as LCD and DLP.

Therefore, the incident light F enters the screen surface perpendicularly. This lenticular lens sheet 10
B sets the focal point of the light entrance side lens portion 12-1 inside the light exit side lens portion 17B-1, so that the image light F incident on the light entrance side lens portion 12 from the left slope is on the opposite side. Out of the inclined surface of the light exit side lens portion 17-1 (F
3). At this time, a part (about 4%) of the light F4 is reflected by the emission-side lens unit 17B-1, and the adjacent light-incidence-side lens unit 12-B.
Head to 2. After the total reflection is repeated by the adjacent light entrance side lens unit 12-2 (F5, F6, F7), the light is further emitted from the adjacent light exit side lens unit 17B-3 (F8). Therefore, as shown in FIG. 9, if the colored layer 13 is formed along the lens surface of the light incident side lens portion 12, this stray light can be effectively removed rather than coloring the entire lenticular lens sheet. can do.

(Lens Part) The lenticular lens sheet 10A efficiently absorbs the external light B totally reflected by the lens part 12 of the light entrance surface 11, as described with reference to FIG. The external light B incident at an angle θ from the light-emitting surface of the adjacent lens unit is totally reflected by the light-entering lens unit 12 and returns to the observation side again, and acts to deteriorate the contrast. At this time, the condition that the colored layer 13 formed along the lens surface of the light incident side lens portion 12 effectively absorbs the external light is such that the same light incident side lens portion 12 performs total reflection twice or more. That is. That is, when returning to the observation side by only one total reflection, only the same effect as when the entire body is uniformly colored can be obtained. In order to perform total reflection two or more times with the same light incident side lens portion 12, the light incident side lens portion 12 has an angle at the steepest point where the light totally reflected at that portion is parallel to the screen surface. It is necessary to have an angle greater than or equal to

FIG. 10 is a diagram showing conditions for performing total reflection twice or more with the same light-entering lens unit. Assuming that the refractive index of the resin constituting the lenticular lens sheet 10A is n, the relationship between φ and θ can be expressed by the following equation. φ = (π / 4) −arcsin [(sin θ) / n] Here, when θ is set to 90 °, φ = (π / 4) −a
rcsin (1 / n), and an angle larger than this angle is
When the light incident side lens unit 12 has the effect of the present invention.

(Coloring Method of Coloring Layer) The coloring of the coloring layer 13 can be performed by using a dye or a fine pigment and mixing or dispersing it in the molding resin of the lenticular lens sheet 10.

(Color of Colored Layer) Colors to be colored are achromatic colors such as gray and three primary colors (red,
One that selectively absorbs or transmits light of a specific color that controls the balance between green and blue) can be used.

(Coloring Density of Coloring Layer) The coloring density of the coloring layer 13 is determined in a portion closer to the light emitting surface than the coloring layer 13 (base layer 15).
It is preferable that the coloring density of the base layer 15 is set to be higher or lower than zero, and to keep the coloring density of the base layer 15 at zero or low in order to suppress the influence of external light without significantly impairing the transmittance of the projection light from the light source.

Table 1 is a table showing the relationship between the transmittance and the contrast of the transmission screen according to this embodiment.

[0038]

[Table 1]

The color density is such that the screen transmittance is 40 to 40%.
It is preferable that the density be 70%. When the color density is reduced so that the transmittance is higher than 70%, the transmittance is improved.
In step 2, the intensity of external light that is totally reflected and returns to the observation side increases, and the contrast deteriorates. Conversely, when the coloring density is increased so that the transmittance is lower than 40%, the transmittance of the image light only deteriorates, and the reflection of external light on the light exit side lens unit 17 becomes relatively conspicuous. Again, the contrast is deteriorated.

Table 1 shows that a lenticular lens sheet having a light absorbing layer provided with a thin colored layer on the light incident surface side of the present invention was prepared by varying the coloring density of the colored layer, and a haze meter (Murakami Color Research Laboratory) This is a table showing the transmittance, the reflectance and the ratio of the transmittance and the reflectance (transmittance / reflectance) by measuring the transmittance and the reflectance using HR-100 (manufactured by HR-100). Here, the measurement of the reflectance was performed at 45 ° light incidence. By lowering the coloring density, the transmittance of the lenticular lens sheet increases, but the reflectance sharply increases when the transmittance exceeds about 70%. This is because the coloring layer 13 cannot sufficiently absorb external light because the coloring concentration becomes low. On the other hand, the lenticular lens sheet of the present invention does not absorb the external light reflected on the observation side (light exit surface side). Therefore, even when the color density is increased and the transmittance is reduced, the ratio between the transmittance and the reflectance is reduced. Is decreasing. Therefore, it is preferable that the coloring be performed so that the transmittance is 40 to 70%.

When a transmissive LCD light source is used as the light source, the output of the transmissive LCD light source is not so large. Is more preferable.

(Dimension of Colored Layer) The thickness t _{1 of the} colored layer 13 is 0.05 times the pitch p of the lenticular lens 12.
As described above, the ratio is more preferably 0.05 to 1.0 times.
The colored layer 13 has a thickness t ₁ of the sheet thickness to.
Is preferably equal to or less than 1/2. In any case, conditions suitable for forming the colored layer 13 in a portion where reflected external light passes well are shown.

FIG. 11 is a diagram showing the thickness of the colored layer of the lenticular lens sheet according to the first embodiment. Further, the colored layer 13, in one light incidence side lens unit 12, toward the thickness t ₂ of the skirt portion than the thickness t ₁ of the top of the lens portion 12, preferably to reduce the thickness thereof ( t ₁ > t ₂ ). When the colored layer 13 is formed to have a uniform thickness, the colored layer 13 has a lower portion 12b than an optical path in the colored layer 13 for the image light incident from the top 12a of the light incident side lens portion 12.
This is because the optical path of the image light incident on the lens becomes longer and is absorbed more. As a result, the intensity of the light emitted at 30 to 40 degrees is reduced.

FIG. 12 is a light diffusion characteristic diagram showing a case where the thickness of the skirt portion of the colored layer of the lenticular lens sheet according to the first embodiment is reduced, as compared with a case where the thickness is made uniform. As shown in FIG. 12, the lenticular lens sheet 10 reduces the thickness at the foot 12b of the colored layer 13 to reduce the intensity of the emitted light as shown in FIG.
Can be suppressed. Further, the thickness of the coloring layer 13 is
It is desirable to form the light diffusion member in accordance with the length of the path of the incident light because light diffusion characteristics as designed by the lens can be obtained.

(Light Diffusing Layer) In the lenticular lens sheet 10, at least the coloring layer 13 is added with a light diffusing agent. As the light diffusing agent, glass beads, an organic crosslinked polymer, or the like can be used. This light diffusing agent is added to the molding resin of the lenticular lens sheet 10 in an amount of about 8 parts by weight, and performs a function of suitably performing vertical diffusion of the projection light from the light source.

This diffusing agent can be mixed into the entire lenticular lens sheet 10. However, if a light diffusing agent is present on the observation side of the colored layer 13, the external light is diffused there and a part thereof is diffused. It is preferable that the diffusing agent of the base material layer 15 be thinned in order to return to the observation side before the temperature reaches the threshold. That is, when the concentration of the diffusing agent mixed in the colored layer 13 is C ₁ and the concentration of the diffusing agent mixed in the base layer 15 is C ₀ ,
It is desirable that the relationship 0 ≦ C ₀ <C _{1 be} satisfied.

(Light Output Surface) Lenticular Lens Sheet 1
Numeral 0 indicates a smooth surface or a mat surface of the light exit side lens portion 17. In the case of a smooth surface, a clear feeling of the image can be obtained. Since the colored layer 13 is formed in the vicinity of the light incident surface 11, reflection by the light incident surface 11 does not occur as compared with the case where a transparent flat panel is arranged on the front surface of the screen. Is obtained.

When the light exit side lens portion 17 has a smooth surface, an antireflection layer, a low reflection layer, a polarizing filter layer, and the like can be provided. In this case, a contrast equivalent to that of a conventional lenticular lens having a light absorbing layer can be obtained. Also, the light exit side lens unit 17
, A hard coat layer, an antiglare layer, and an antistatic layer can be formed on the surface. In addition, the surface of the light emitting side lens portion 17 has an advantage that when it has a matt surface, it is anti-glare, and there is no reflection on the screen surface.

(Manufacturing Method of Lenticular Lens) The lenticular lens sheet of the present invention has, for example, a roll-shaped mold having a light-entering surface shape having an inverted shape of a lenticular lens, and a shape of a light-emitting side lens portion and a light absorbing layer. The light emitting surface forming roll-shaped molds are arranged in parallel, and a colored resin is coated on the light incident surface side between them, and a transparent or thinner colored resin (light diffusing agent) is formed on the light emitting surface side. May be extruded in two layers and molded. Alternatively, a similar mold may be used to extrude and mold the resin, and at the same time, along the mold on the light incident surface side, It can be produced by leading a colored film and laminating the colored film. In the lenticular lens sheet of the present invention, a lens layer can be formed on a film substrate using a colored ultraviolet curable resin.

(Another Embodiment of Lenticular Lens Sheet) FIG. 13 is a view showing another embodiment of the lenticular lens sheet according to the present invention. The lenticular lens sheets 10 </ b> C to 10 </ b> E of these embodiments have a lens layer formed on the film substrate 50 using a colored ultraviolet curable resin.

The lenticular lens sheet 10C shown in FIG. 13A has a light incident side lens portion 12 formed on the light incident side of the film substrate 50 using a colored ultraviolet curable resin. The light emitting side lens portion 17, the convex portion 18, and the light absorbing layer 19 are formed. When used in a projection system having a single tube light source, such as an LCD, which does not require the function of correcting the convergence angle, the light emitting side lens unit 17 may be a concave light emitting side lens unit 17B (see FIG. 4). It is possible.

The lenticular lens sheet 10D shown in FIG. 13B uses a colored ultraviolet curable resin to form a light incident side lens portion 12 formed on the light incident side of the film substrate 50.
The colored layer 13 is formed along the line, and the light absorbing layer 19 is formed directly on the light exit side of the film substrate 50. FIG. 13 (C)
The lenticular lens sheet 10E uses a colored ultraviolet curable resin to form the light entrance side lens portion 12 on the light entrance side of the film substrate 50, and to form the light absorption layer 19 on the light exit side of the film substrate 50. It was formed directly.

FIG. 14 is a view showing still another embodiment of the lenticular lens sheet according to the present invention. The lenticular lens sheets 10F of these embodiments,
10G is obtained by forming colored layers 13F and 13G on a portion including the top of the entrance / exit lens portion 12. FIG.
The lenticular lens sheet 10F of (A) has a colored layer 13F formed in a wedge shape. FIG.
The lenticular lens sheet 10G of (B) has a light incident side lens portion 12 formed on the light incident side of the film base material 50, and a colored layer 13G formed in a plane including a top portion thereof.

(Another Embodiment of Transmissive Screen) FIG. 1
FIG. 5 is a view showing another embodiment of the transmission screen according to the present invention. In this embodiment, a front panel (front panel) 30 for a display is further arranged on the observation side of the lenticular lens sheet 10.

The lenticular lens sheet 10 is often mixed with a light diffusing agent in order to give vertical diffusion characteristics. Due to the diffusing agent, part of the projected light becomes stray light and is emitted from a unit lens element different from the original pitch. Further, as shown in FIG. 2, part of the light incident from the light exit side lens unit 17 returns to the observation side irrespective of the total reflection by the light entrance side lens unit 12 described above. In this embodiment,
In order to prevent the contrast from being lowered by the diffusing agent, the lenticular lens sheet 1 mixed with the diffusing agent is used.
By forming a colored layer on the observation side (or the most observation side) rather than 0, it is possible to more effectively prevent a decrease in contrast.

The transmission screen 1A shown in FIG.
On the observation side of the lenticular lens sheet 10, a front panel 30A composed entirely of a colored base material 31A is arranged.

The transmission screen 1B shown in FIG.
On the observation side of the lenticular lens sheet 10, a front panel 30B including a transparent base material 31B and a colored layer 32B formed on the light exit surface side of the base material 31B is arranged.

The transmission screen 1C shown in FIG.
On the observation side of the lenticular lens sheet 10, a front panel 30C including a transparent base material 31C and a colored layer 32C formed on the light incident surface side of the base material 31C is arranged.

The transmission screen 1D shown in FIG.
In addition to the structure of the lenticular lens sheet 10, a front panel 30D made of a transparent base material 31D is arranged on the observation side of the lenticular lens sheet 10H provided with the coloring layer 13H near the light exit surface 14. Of course, each front panel 30 has an anti-reflection layer, a low reflection layer,
Various functional layers such as a polarizing filter layer, an antistatic layer, an antiglare treatment layer, and a hard coat treatment layer can be formed.

(Modifications) Various modifications and changes are possible without being limited to the embodiments described above, and these are also within the equivalent scope of the present invention. For example, the light entrance side lens unit has been described as an example of a lenticular lens, but a “fly-eye lens sheet” that diffuses light also in the vertical direction.
Similarly, the present invention can be applied. The front panel 30 may be provided with, for example, a colored lenticular lens for vertical diffusion on the surface on the incident side. In this case, unnecessary light such as external light and stray light is totally reflected on the surface of the lenticular lens, so that better contrast can be obtained than when uniform coloring is applied to the entire front plate.

[0061]

Next, the present invention will be described in more detail with reference to specific examples. Here, BS molded by two-layer extrusion
A lenticular lens in which a colored layer is formed on the light incident surface is produced, and the result of the evaluation is shown. The lenticular lenses of this example and comparative example have a pitch of 0.72 mm,
The distance between the light entrance side lens section and the light exit side lens section is 0.87 m
m, the input / output light lens part is a convex lens, and the BS ratio is 50%
It is. Here, three types of a colored layer having a thickness of 0.14 mm (Example), a thinly colored layer (Comparative Example 1), and a non-colored layer (Comparative Example 2) were prepared and evaluated. The results are as shown in Table 2 below.

[0062]

[Table 2]

Here, the transmittance and the reflectance were measured by a haze meter in the same manner as described above. The contrast was determined by combining a lenticular lens sheet with a Fresnel lens sheet in a dark room, setting the projection TV, displaying a black-and-white pattern, and measuring the luminance ratio of the white portion to the black portion near the center of the screen. Comparative Example 1
Compared with the embodiment, the luminance of the black portion is higher and the ratio is relatively smaller.

The brightness of the bright room (TV-OFF) is obtained by turning on the fluorescent lamp in the room and turning off the power of the TV from the front (0 °) and obliquely (40 °) from the center of the TV. This is the result of measuring the luminance of the sample. Since the measurement is performed with the power supply of the TV turned off, the reflection of environmental light is measured. The reflection of ambient light in the front direction (brightness of a bright room 0 °)
Although there is almost no difference between the embodiment and Comparative Examples 1 and 2, reflection of ambient light in an oblique direction (brightness of a bright room of 40 °).
Is smaller in the example than in the comparative example.

[0065]

As described above in detail, according to the present invention, it is possible to suppress the reflection of external light and increase the contrast without significantly reducing the intensity of the image light, and it is possible to reduce the thickness of the system. became.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a transmission screen according to the present invention.

FIG. 2 is an explanatory view showing a first embodiment of a lenticular lens sheet and a first function of a colored layer according to the present invention.

FIG. 3 is an explanatory view showing a second embodiment of a lenticular lens sheet according to the present invention and a first function of a colored layer.

FIG. 4 is an explanatory view showing a third embodiment of a lenticular lens sheet according to the present invention and a first function of a colored layer.

FIG. 5 is an explanatory diagram showing a lenticular lens sheet (body coloring type) according to a comparative example.

FIG. 6 is a diagram showing a conventional lenticular lens sheet with BS.

FIG. 7 is an explanatory diagram showing a second function of the coloring layer of the lenticular lens sheet according to the first embodiment.

FIG. 8 is a view for explaining a lenticular lens sheet (body coloring type) according to a comparative example.

FIG. 9 is an explanatory diagram showing a second function of the colored layer of the lenticular lens sheet according to the third embodiment.

FIG. 10 is a diagram illustrating an angle of a lenticular lens sheet according to a second embodiment with respect to a screen surface.

FIG. 11 is a diagram illustrating the thickness of the colored layer of the lenticular lens sheet according to the first embodiment in the lens.

FIG. 12 is a graph showing light diffusion characteristics when the thickness of a colored layer is constant and when the thickness is changed.

FIG. 13 is a view showing another embodiment of the lenticular lens sheet according to the present invention.

FIG. 14 is a view showing still another embodiment of the lenticular lens sheet according to the present invention.

FIG. 15 is a view showing another embodiment of the transmission screen according to the present invention.

[Explanation of symbols]

 1, 1A to 1D Transmission screen 10, 10A to 10H Lenticular lens sheet 11 Light entrance surface 12 Light entrance side lens portion 13 Colored layer 14 Light exit surface 15 Base layer 17, 17B Light exit side lens portion 18 Convex portion 19 Light absorption Layer 20 Fresnel lens sheet 21 Fresnel lens 30 (30A to 30D) Front panel 50 Film base

Claims (7)

[Claims] A light-receiving side lens section in which a plurality of light-collecting unit lens elements formed in a convex shape on the light-entering surface side of the base material layer are arranged; A colored layer formed at least in the vicinity of the light incident surface of the lens portion; and a light absorbing layer formed on the light exit surface side of the base layer and on the non-light collecting portion of the light incident side lens portion. Lenticular lens sheet. 2. A light-entering side lens section in which a plurality of unit lens elements having a light-collecting property formed in a convex shape on the light-incident side of the substrate layer are arranged. A colored layer formed at least in the vicinity of the light incident surface of the lens portion, and a light emitting side lens portion formed on the light emitting surface side of the base material layer and near the light collecting portion of the light incident side lens portion; A light-absorbing layer formed on a light-exiting surface side of the base material layer and on a non-light-collecting portion of the light-incident-side lens portion. 3. The lenticular lens sheet according to claim 2, wherein the light-emitting-side lens portion is convex or concave on the light-emitting surface side. 4. The lenticular lens sheet according to claim 1, wherein a diffusing agent is added to at least the coloring layer. 5. The method according to claim 1, wherein:
13. A transmissive screen, comprising: the lenticular lens sheet described in the above section; and a Fresnel lens sheet disposed on the light source side of the lenticular lens sheet. 6. The transmissive screen according to claim 5, further comprising a front plate disposed on the observation side of the lenticular lens sheet, wherein the front plate is colored near a light incident surface, near a light emitting surface, or entirely. A transmission screen characterized by the following. 7. The transmission screen according to claim 5, wherein the lenticular lens sheet is colored near a light exit surface.