JP3335588B2 - Transmission screen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the, LCD (Liquid Crystal Display) or DMD (Digtal Micro - mirror Device) permeable to the image from the image light source suitable for observation by projecting with a cell structure as such It relates to an oversized screen.

[0002]

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

FIG. 4 is a view showing an example of a conventional transmission type projection screen. In order to satisfy the above-mentioned requirements, the transmission type projection screen forms a lens unit 42 such as a lenticular lens for condensing light on a light entrance surface 41, and a light exit surface 44 near a focal point of the lens unit 42, and a light exit surface 44. Face 44
A lenticular lens sheet 40 with a BS that diffuses light and reduces the influence of external light at the same time by providing a non-light emitting portion 47 in a part of the light shielding portion (black stripe: hereinafter referred to as BS) 48. It is used.

Further, a projection television using an LCD or DMD as an image light source has been developed. 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.

[0005]

However, the aforementioned LC
In a projection television using D or DMD, a lattice pattern caused by a cell structure of a panel is projected on a screen. Therefore, when an image is projected and observed on a lenticular lens sheet having a periodic structure at a constant pitch as described above. Moire may occur due to the sampling effect of the lenticular lens.

In order to prevent the occurrence of such moiré, it is said that it is preferable that the pitch of the lenticular lens is reduced so as to be 1 / 3.5 or less of the pitch of the projected grating pattern. In addition, LCD and DM
In the projection television using D, image glare called scintillation occurs, but reducing the pitch of the lenticular lens is also effective in weakening the scintillation.

On the other hand, when the lenticular lens sheet with the BS shown in FIG. 4 is used for the transmission type projection screen, the light is diffused over a wide range of 40 ° or more, and at the same time, the BS is formed. The distance between the light entrance lens and the light exit surface must be about 1.3 times the lens pitch. For this reason, in order to make the moire between the lattice pattern projected on the screen and the lens pitch inconspicuous, the lens pitch must be 0.4 mm or less, and the lens thickness must be 0.54 mm or less.

However, as described above, when the thickness of the screen is reduced, the rigidity of the screen is reduced, and it becomes difficult to hold the screen flat. Moreover, it is very difficult to accurately mold such a thin lens sheet by extrusion molding or the like.

[0009] Further, for the above-mentioned reasons, the transmission type projection screen has been used for projection televisions using LCDs and DMDs by coloring a light-emitting side single-sided lenticular lens or a light-entering side single-sided lenticular lens. I have.

The light-emitting side single-sided lenticular lens has a sectional shape of a part of a circle or an ellipse, and a shape utilizing total reflection. In the former case where the cross section is a part of a circle or an ellipse, the viewing angle cannot be widened because the lens angle with respect to the projected light exceeds the critical angle at the foot of the lens shape and causes total reflection. For the latter that uses total reflection,
Due to its peculiar shape, there is a problem that accurate mold transfer cannot be performed by extrusion molding, and it must be manufactured by cast molding with low productivity.

FIG. 6 is a diagram showing the relationship between the inclination angle of the light incident position of the lenticular lens sheet on one side of the light incident surface and the light emission angle. In FIG. 6, φ is the lens angle at the foot of the light-entering lens, θ is the emission angle of light incident on the foot of the lens, h is the height of the light-entering lens, and L is the light-entering point (of the lens). It is the distance from the skirt portion) to the focal point. Table 4 shows that
The light exit angle and the position of the condensing point with respect to the lens angle of the skirt portion of the light incident lens are shown. As shown in FIG. 6 and Table 4, the incident side single-sided lenticular lens must have an angle φ of the bottom of the lens shape of 60 ° or more as shown in FIG. Need to be bigger. However, when the angle of the skirt is increased, as shown in FIG. 3B, external light incident from the light-emitting surface side is totally reflected by the light-entering lens and re-emitted from the light-emitting surface and observed. There is a problem that the contrast of an image is significantly reduced. Usually, since many lenticular lens sheets with BS form a light exit surface almost at the focal point of the light entrance lens, the distance between the light entrance lens and the light exit surface is h + L. Are 1.41, 7 when φ is 60 °
When the angle is 0 °, the value is 1.25.
It can be seen that the distance between the light emitting surfaces needs to be designed to be approximately 1.3 times the lens pitch. Therefore, when the lens pitch is reduced, the thickness of the lens sheet is reduced, rigidity is reduced, and molding becomes difficult.

[0012]

[Table 4]

The present invention, without reducing the intensity of image light so much, suppressing reflection of external light, it is possible to increase the contrast, moreover, aims to provide a transparently screen you allow fine pitch And

[0014]

In order to solve the above-mentioned problems, a lenticular lens sheet is provided.
Disposed on the light source side of the lenticular lens sheet.
Transmission screen including a Fresnel lens sheet
The lenticular lens sheet may include a base layer, a lens portion having a lenticular lens shape formed in a convex shape on one side of the light incident surface of the base layer, and at least a vicinity of the light incident surface of the lens portion. The base layer is not colored or is colored thinner than the colored layer, the lens pitch of the lens portion is 0.4 mm or less, the colored layer, Its thickness is 0.05 to 1 of the pitch of the lenticular lens shape.
This is a transmission type screen characterized by being 0 times.

According to a second aspect of the present invention, there is provided a transmission system according to the first aspect.
A transparent screen , wherein the colored layer has a shape following the lens shape.
It is down.

[0016] The invention of claim 3 is claim 1 or claim 2.
A transmissive screen according to the colored layer is characterized by being formed along the path of the total reflected light
It is a transmission screen .

According to a fourth aspect of the present invention, there is provided the first to third aspects.
A transmissive screen according to any one of the colored layer is a transmissive screen, characterized in that its thickness is less than 1/2 of the sheet thickness.

The invention according to claim 5 is the invention according to claims 1 to 4.
In the transmission screen according to any one of the above, the lens portion, when the lenticular lens shape is substantially elliptical in cross section, and the horizontal diameter is a, the vertical diameter is b,
The thickness t1 of the colored layer at the top of the lenticular lens shape is substantially ^{t1 = b-b 2 / (} a 2 + b 2)
A transmission screen characterized by being expressed by a formula of ^1/2 .

The invention of claim 6 is the invention of claims 1 to 5
A transmissive screen according to any one of, at least the colored layer, a transmission type screen, characterized in that the diffusion agent is added.

The invention according to claim 7 is the transmission according to claim 6.
In the mold screen , the concentration of the diffusing agent mixed in the colored layer is C1, and the concentration of the diffusing agent mixed in the base layer is C0.
When a is a transmissive screen, characterized in that 0 ≦ C0 <C1 is satisfied.

[0021] The invention of claim 8 is the invention of claims 1 to 5.
In the transmission screen according to any one of the above, the coloring layer is not mixed with a diffusing agent, the base layer is not colored or colored less than the colored layer, further, A transmission screen including a diffusion layer formed between the coloring layer and the base material layer and mixed with a diffusing agent.

According to a ninth aspect of the present invention, there are provided the first to eighth aspects.
A transmissive screen according to any one of the lenticular lens shape, a transmissive screen to which the tangent with respect to the lenticular lens sheet surface, characterized in that it includes a portion to be at an angle greater than the critical angle It is.

According to a tenth aspect of the present invention, in the transmission screen according to any one of the first to ninth aspects,
The base material layer is a transmissive screen characterized in that the light emitting surface is a flat surface or a mat surface.

[0024] The invention of claim 11 is the invention according to claim 10.
In the transmission screen , the base layer has 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 formed on the light exit surface. Transmission type screw
It is over emissions.

[0025] The twelfth aspect of the present invention is the first aspect of the present invention.
12. The transmission screen according to any one of items 11 to 11 , further comprising a display front plate disposed on the observation side of the lenticular lens sheet.

According to a thirteenth aspect of the present invention, in the transmissive screen according to the twelfth aspect , the display front plate has a base layer and a lenticular lens formed in a convex shape on a light incident surface of the base layer. A lens part having a shape, and a colored layer formed at least in the vicinity of a light incident surface of the lens part, wherein the light emitting surface of the base material layer is a flat surface or a mat surface. It is a type screen.

According to a fourteenth aspect of the present invention, in the transmission screen according to the thirteenth aspect, the base layer has an antireflection layer, a low reflection layer, a polarizing filter layer, an antistatic layer, and an antiglare treatment on its light emitting surface. A transmission screen, wherein at least one of a layer and a hard coat treatment layer is formed.

According to a fifteenth aspect of the present invention, the first to the fifth aspects are provided.
14. The transmission screen according to any one of items 14 to 14, wherein the total light transmittance is 40 to 70%.

[0029]

[0030]

[0031]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The present invention will be described in more detail with reference to an embodiment.

FIG. 1 is a view showing an embodiment of a lenticular lens sheet and a transmission screen according to the present invention. FIG. 2 is a diagram illustrating the behavior of external light reflected by the lenticular lens sheet.

(Embodiment of Transmission Screen) As shown in FIG. 1A, the transmission screen 1 has a lenticular lens sheet 10 and a Fresnel lens sheet 20.
And one lens type LCD
A rear projection system is configured together with the light source 2 of the projector.

(Embodiment of Lenticular Lens Sheet) In the lenticular lens sheet 10, a lens portion 12 having a convex lenticular lens shape is formed on a light incident surface 11 as shown in an enlarged view in FIG. The colored layer 13 is formed near the light incident surface 11 of the lens unit 12. The base layer 15 is formed from the colored layer 13 to the light exit surface 14.
Up to the layer. The colored layer 13 has a function of increasing contrast even though it is a lenticular lens sheet 10 having one side of light.

(Function of Colored Layer) Next, the fact that the lenticular lens sheet 10 according to the present embodiment can obtain good contrast will be described in comparison with the lenticular lens sheet 60 according to the conventional example. FIG. 3 is an explanatory diagram showing the function of the light incident surface coloring layer of the lenticular lens sheet according to the present embodiment in comparison with a lenticular lens sheet (body coloring type) according to a conventional example.

Conventional lenticular lens sheet 60
Is a light incident surface single-sided lenticular lens sheet,
The base layer 65 is of a body coloring type in which all of the base layers are colored. The external light B1 incident from the observation side is totally reflected by the lens portion 62 formed on the light incident surface 61, and the external light D4 is emitted again to the observation side. At this time, the external light D1 repeats reflection along the lenticular lens shape of the lens unit 62 (D1 → D2 → D3 → D4).

In the lenticular lens sheet 10 of the present embodiment, since the coloring layer 13 is formed along the path of the totally reflected light, the external light B The optical path length in the colored layer 13 becomes 5 to 10 times. On the other hand, in the case of the conventional body coloring type lenticular lens sheet 60, the ratio is at most 2 to 2.
Only about three times. For this reason, the lenticular lens sheet 10 of the present invention can suppress the reflection of the external light B without significantly lowering the intensity of the image light A, and can provide a screen with good contrast.

(Lens Part) The lenticular lens sheet 10 of the present embodiment efficiently absorbs external light B totally reflected by the lens part 12 of the light entrance surface 11. Therefore, the lens unit 12 must have a portion having an inclination at which the angle φ with respect to the screen surface shown in FIG. 5 is at least equal to or greater than the critical angle (about 42 °), and the lens unit 12 has an inclination smaller than this. In the case of (1), the superiority cannot be exhibited with respect to the lenticular lens sheet 60 of the body coloring type shown in FIG. FIG. 5 shows that the incident angle φ when the external light perpendicularly incident on the lenticular lens sheet exits from the light incident lens or is totally reflected by the light incident lens,
It is a figure explaining that it is equal to the lens angle with respect to the screen surface of the part. In FIG. 5, LL ′ (tangent line)
And MM '(normal) intersect at a right angle and i = i', so that φ = φ '. Therefore, in order to totally reflect the external light on the light-entering lens surface, the lens angle φ is equal to the critical angle sin ⁻¹ (1
/ N) It is necessary that the light-entering lens has a portion equal to or greater than [n is the refractive index of the lens sheet].

However, as shown in Table 4, the inclination is 42
At about ゜, only a diffusion angle of about 25 ° can be obtained,
Normally, the lens unit 12 is set so that the diffusion angle is 40 ° or more.
The lenticular lens shape desirably has a portion having an angle of about 60 ° or more.

(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) The 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).
And the color density of the base material layer 15 is preferably kept to zero or low in order to suppress the influence of external light without significantly impairing the transmittance of the light projected from the light source 2.

FIG. 7 is a diagram showing the relationship between the transmittance and the contrast of the transmission screen according to this embodiment.
The coloring density is preferably such that the screen transmittance is 40 to 70%. When the coloring density is reduced so that the transmittance is higher than 70%, the transmittance is improved, but the intensity of external light that is totally reflected by the lens unit 12 and returns to the observation side is increased, thereby deteriorating the contrast. . 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 emitting surface 14 becomes relatively conspicuous. Causes deterioration of contrast. FIG. 7 shows a single-sided lenticular lens sheet provided with a thin colored layer on the light incident surface side of the present invention by changing the coloring concentration of the colored layer in various ways, and using a spectrophotometer (UV2100 manufactured by Shimadzu Corporation). FIG. 5 is a diagram in which the transmittance and the reflectance are measured using the above method, and the reflectance and the ratio of the transmittance and the reflectance (transmittance / reflectance) are plotted with respect to the transmittance. Reflectivity is on the left axis, and the ratio of transmittance to reflectance is on the right axis. 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 becomes insufficient in absorbing the 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. Decreases, and the ratio of the transmittance to the reflectance is 50%.
%, And falls on both sides with a peak. Therefore,
It is preferable to color so that the transmittance is 40 to 70%.

When a transmissive LCD light source is used as the light source 2, 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.
It is preferable that the ratio is 1.0 to 1.0. The coloring layer 13
It is preferable that the thickness t ₁ is not more than の of the thickness to of the sheet. In any case, conditions suitable for forming the colored layer 13 in a portion where reflected external light passes well are shown.

(Shape of Colored Layer) FIG. 8 is a view for explaining the optimum value of the thickness of the colored layer of the lenticular lens sheet according to the present embodiment. As described above, the lenticular lens sheet 10 of the present embodiment utilizes the fact that external light incident from the light-emitting surface (observation side) travels along the lens portion 12, so that the coloring layer 13 12
It is desirable to make the shape along.

In this case, the colored layer 13 has a minimum geometric optical thickness t _min equal to the lens height at which the inclination の of the tangent line T of the lens portion 12 becomes ψ = 45 °. Can be calculated by the following equation (1) when the cross-sectional shape is an ellipse. t ₁ = b−b ² (a ² + b ² ) ^1/2 (1) where a and b are the horizontal diameter (short diameter) and the vertical diameter (long diameter) of the ellipse.
It is. At this time, the contrast is the best.

When the conic coefficient is k = 0.45 (= a ² / b ² −)
In the case of an elliptical lenticular lens having a lens angle of about 1 ° and about 60 °, t ₁ is about 1/10 of the pitch of the lenticular lens shape.

On the other hand, the colored layer 13 does not conform to the lens shape, for example, as shown in FIG.
Even if the interface between the substrate and the base layer 15 is flat, as can be expected from the comparison of FIGS.
A better lenticular lens sheet 10A than that of the body coloring type is obtained. In this case, the colored layer 13
It is preferable that the thickness of the colored layer 13 be equal to or less than the pitch of the lenticular lens shape or at least equal to or less than の of the sheet thickness in order to exhibit the effect brought to the lens portion 12 side.

(Thickness of foot of colored layer) FIG.
The thickness of the colored layer of the lenticular lens sheet according to the embodiment.
FIG. Further, the coloring layer 13 includes one lens unit 1.
2, the thickness t of the top of the lens portion 12₁More hem
Thickness t_TwoIs preferable to reduce its thickness (t
₁> T _Two). When the colored layer 13 is formed to have a uniform thickness,
Coloring layer of image light incident from the top part 12a of the lens part 12
13, the optical path of the image light incident on the foot 12 b
Is longer and is absorbed more. So
As a result, the intensity of light emitted at 30 to 40 ° is low.
It becomes.

FIG. 10 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 present embodiment is reduced, as compared with a case where the thickness is made uniform. This lenticular lens sheet 10 has a color layer 1
1 by reducing the thickness at the bottom 12b of FIG.
As shown in FIG. 0, the above-described phenomenon (a decrease in the intensity of the emitted light) can be suppressed. Furthermore, if the thickness of the colored layer 13 is formed according to the length of the path of the incident light, it is desirable to obtain light diffusion characteristics as designed by the lens.

(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 diffusing the projection light from the light source 2 vertically.

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, external light is diffused there and a part thereof is diffused. It is preferable that the diffusing agent of the base material layer 15 is thinned in order to return to the observation side before the temperature reaches the threshold value. 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.

When an anti-reflection layer, a polarizing filter layer, a hard coat layer, etc., which will be described later, are formed by laminating films having these functions, the light exit surface 14
Is preferably a flat surface. In that case, laminating is easier if the diffusing agent is not mixed into the base layer 15.

Further, a diffusing agent layer (intermediate layer) is formed in the middle of the coloring layer 13 on the light incident surface without mixing a diffusing agent, and is used to absorb light reflected by the diffusing agent. A colored layer having a low concentration can be formed on the observation side [FIG.
(B), (c)].

(Light output surface) Lenticular lens sheet 1
0 indicates that the light exit surface 14 is a flat surface or a mat surface. In the case of a flat surface, a clear feeling of the image can be obtained. Since the coloring 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 entire surface of the screen. Is obtained.

When the light exit surface 14 is a flat 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. In addition, a hard coat layer,
An antiglare layer and an antistatic layer can also be formed. When the light emitting surface 14 is formed as a matte surface, the light emitting surface 14 has an advantage that it is anti-glare and is not reflected on the screen surface.

(Sheet Thickness) As described above, in the lenticular lens sheet of the present embodiment, since the light emitting surface 14 is flat, various functional layers can be formed. By setting the thickness to 0.5 mm or more, a front plate used in a screen using a conventional lenticular lens sheet with BS can be eliminated.

(Light Source) Since the lenticular lens sheet 10 of the present embodiment does not have a lens for correcting the optical axis on the light exit surface 14, the light source 2 is a single lens that projects image light from one lens. It is preferable to use in combination with a type, single tube type projector. Further, the light source 2 separates the light of the lamp into three primary colors of light by a dichroic mirror, transmits the light through the LCD, gives image information, combines the light again, and projects the light again, such as an LCD projector or a DMD projector. Can be suitably used.

(Method of Manufacturing Lenticular Lens) The lenticular lens sheet of the present invention is used for molding a light emitting surface having a flat or mat-like surface, for example, a light entering surface having a reverse shape of a lenticular lens. The roll-shaped molds are arranged in parallel, and a colored resin is provided on the light incident surface side between them, and on the light emitting surface side, a resin colored transparent or thinner than a colored layer (a light diffusing agent may be included. ) Is extruded and molded in two layers, and a similar mold is used to extrude and mold the resin, and at the same time, a colored film is formed along the mold on the light incident surface side. And laminating the colored film. In addition, the lenticular lens sheet of the present invention uses a colored ultraviolet curable resin,
The lens layer can be formed on a film substrate.

(Other Embodiments of Lenticular Lens)
FIG. 11 is a view showing another embodiment of the lenticular lens sheet according to the present invention. The lenticular lens sheet 10A shown in FIG. 11A is an example of a shape in which the colored layer 13 does not conform to the lens shape. This lenticular lens sheet 10A can be used even if the interface between the colored layer 13 and the base material layer 15 is flat, as shown in FIG.
As can be expected from the comparison of (B), a better lenticular lens sheet is obtained than the body-colored type. Further, in order for the colored layer 13 to exhibit the effect brought to the lens portion 12 side, it is preferable that the thickness of the colored layer 13 be equal to or less than the pitch of the lenticular lens, or at least 1/2 or less of the sheet thickness. .

The lenticular lens sheet 10B shown in FIG. 11 (b) has a colored layer 13 formed along the lens portion 12 and a base layer 15B which is lightly colored without containing a diffusing agent.
Also, an intermediate layer (diffusion layer) 16 containing a diffusing agent was formed between the colored layer 13 and the base layer 15B.

The lenticular lens sheet 10C shown in FIG. 11C has a colored layer 13 formed along the lens portion 12 and a base material layer 15B provided on the light emitting surface 14 side and containing no diffusing agent. In addition, a base layer 15C that does not contain a diffusing agent and is not colored, and an intermediate layer (diffusion layer) 16C that contains a diffusing agent is formed between the coloring layer 13 and the base layer 15C.

Lenticular lens sheets 10B, 10
According to C, reflected light can be effectively absorbed by the diffusing agent and the lightly colored layer.

(Another Embodiment of Transmission Screen) FIG. 1
FIG. 2 is a view showing another embodiment of the transmission screen according to the present invention. Lenticular lens 10 of the present embodiment
Can form a transmission screen 1A in combination with a Fresnel lens sheet 20 (or a film Fresnel lens sheet) having a Fresnel lens formed on the light exit side.
It is preferable to increase the brightness uniformity of the image.

In this embodiment, a display front plate 30 is arranged on the observation side of the lenticular lens sheet 10.

(Embodiment of Display Front Plate) The display front plate 30 has, for example, a colored lenticular lens 32 for vertical diffusion on the incident side surface, and external light and stray light on the surface. Since unnecessary light such as light is totally reflected, better contrast can be obtained than when uniform coloring is applied to the entire front plate. Of course, the display front panel 30 can form various functional layers such as an antireflection layer, a low reflection layer, a polarizing filter layer, an antistatic layer, an antiglare treatment layer, and a hard coat treatment layer.

[0068]

Next, the present invention will be described in more detail with reference to specific examples. (Example 1) A lenticular lens sheet 10 is made of an impact-resistant acrylic resin (refractive index: 1.51), and the lens portion 12 has a pitch P = 0.2 mm and a lens lateral diameter a = 0.
12, the vertical diameter b = 0.15 mm, and the sheet thickness t ₀ =
The colored layer 13 was formed so as to have a thickness of 1.0 mm and a thickness t _{1 of} 0.06 mm.

(Example 2) A transparent film having an antireflection layer formed thereon was laminated on the light emitting surface of the lens portion 12 formed in the same manner as in Example 1.

(Comparative Example 1) A single-sided lenticular lens sheet having the same shape as in Example 1 and having a body coloring and having substantially the same screen gain was formed.

The lenticular lens sheets of Example 1 and Comparative Example 1 were combined with a Fresnel lens sheet mixed with an acrylic bead diffusing agent having an average particle diameter of 30 μm to obtain an LC.
Example 1 on the right side of a rear-projection television using a D light source
When the lenticular lens sheet of Example 1 was set on the left side with the lenticular lens sheet of Comparative Example 1 and compared and observed in a room where a fluorescent lamp was turned on, the screen of Example 1 had better contrast.

Subsequently, Example 1, Example 2, Comparative Example 1,
In addition, a lenticular lens sheet with BS having a pitch p = 0.72 (BS ratio: 45%) is combined with a Fresnel lens sheet mixed with an acrylic bead diffusing agent having an average particle diameter of 30 μm to measure the transmittance and reflectance at 550 nm. When measured with a photometer (Shimadzu Corporation UV2100) and the ratio of transmittance to reflectance (transmittance / reflectance) was calculated, Example 1 was twice as large as Comparative Example 1 as shown in Table 1. As described above, Example 2 had a value equivalent to that of the lenticular lens with BS.

[0073]

[Table 1]

(Example 3) The lenticular lens sheet 10 is made of an impact-resistant acrylic
Is a pitch P = 0.4 mm, a lens lateral diameter a = 0.12,
The vertical diameter b = 0.28 mm, and the sheet thickness t ₀ = 1.0
mm, the colored layer 13 was formed with a thickness t ₁ = 0.06 mm (the ideal colored layer thickness was 0.056 mm). When the transmittance and the reflectance of the lenticular lens sheet were measured by a spectrophotometer, the transmittance was 65%, the reflectance was 7.2%, and the transmittance / reflectance ratio was 9.0. As a comparative example, a molded article having the same shape and a colored layer thickness of t ₁ = 0.10 mm had a transmittance of 62%, a reflectance of 8.0%, and a transmittance / reflectance ratio of 7.8.

(Example 4) A lenticular lens sheet 10 is made of an impact-resistant acrylic resin (refractive index 1.51). The lens part 12 has a pitch P = 0.14 mm and a lateral lens diameter a = 0.07. , The vertical diameter b = 0.09 mm,
Sheet thickness t ₀ = 0.9 mm, coloring layer 13 has thickness t ₁ =
It was formed at 0.04 mm. Sample 4-1 was prepared by mixing a styrene bead in the colored layer without mixing a diffusing agent into the base layer.
Part by weight was mixed. In Sample 4-2, 0.1 parts by weight of acrylic beads were used as the base material layer, and styrene beads were used as the colored layer.
0 parts by weight were mixed. In Sample 4-3, 0.9 parts by weight of styrene beads was mixed into both the base layer and the colored layer. Table 2
As shown in Table 2, the lower the diffusivity of the substrate layer, the better the contrast.

[0076]

[Table 2]

(Example 5) The lenticular lens sheet according to claim 1 was prepared by using a methacrylic material and changing the plate thickness by a two-layer extrusion method. And fixed. Then, the set transmission screen was set on a transmission projection TV, and the reflection of the room light under the room light was evaluated. Further, a front plate made of a currently used methacrylic material was simultaneously evaluated as a comparative example. Table 3 shows the results.

[0078]

[Table 3]

As shown in Table 3, with the lenticular lens sheet having a plate thickness of 1.5 mm or more, distortion of the reflected image was difficult to recognize, and the appearance was good. In addition, the same result was obtained with the same plate thickness as compared with the front plate.

[0080]

As described above in detail, according to the present invention, reflection of external light can be suppressed, contrast can be increased without significantly lowering the intensity of image light, and fine pitch can be achieved. Was.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a lenticular lens sheet and a transmission screen according to the present invention together with external light.

FIG. 2 is a ray tracing diagram of external light reflected by the lenticular lens according to the present embodiment.

FIG. 3 is a diagram showing a comparison between a lenticular lens sheet of the present invention and a conventional single-sided lenticular lens sheet.

FIG. 4 is a view showing a conventional lenticular lens sheet with BS.

FIG. 5 is a diagram for explaining an angle of the lenticular lens sheet of the present embodiment with respect to a screen surface.

FIG. 6 is a diagram showing the relationship between the angle of inclination of the lenticular lens sheet at the position where light is incident and the light emission angle.

FIG. 7 is a diagram showing a relationship between transmittance and contrast of the transmission screen according to the embodiment.

FIG. 8 is a diagram showing an optimum value of a thickness of a coloring layer of the lenticular lens sheet according to the embodiment.

FIG. 9 is a view for explaining the thickness of the colored layer of the lenticular lens sheet according to the present embodiment in one lens.

FIG. 10 is a graph showing light diffusion characteristics when the thickness of a colored layer is constant and when the thickness is changed.

FIG. 11 is a view showing another embodiment of the lenticular lens sheet according to the present invention.

FIG. 12 is a view showing another embodiment of the transmission screen according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transmissive screen 2 Light source 10, 10A, 10B, 10C Lenticular lens sheet 11 Light entrance surface 12 Lens part 13 Color layer 14 Light exit surface 15 Base layer 16 Diffusion layer 20 Fresnel lens sheet 30 Front plate for display

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G02B 3/00 G02B 3/06 G03B 21/62

Claims (15)

(57) [Claims] 1. A lenticular lens sheet and a lenticular lens sheet disposed on a light source side of the lenticular lens sheet.
A transmissive screen including a Fresnel lens sheet
The lenticular lens sheet has a base layer, a lens portion having a lenticular lens shape formed in a convex shape on one side of the light incident surface of the base layer, and at least a vicinity of the light incident surface of the lens portion. The base layer is not colored or is colored thinner than the colored layer, the lens pitch of the lens unit is 0.4 mm or less, and the colored layer is A transmission screen having a thickness of 0.05 to 1.0 times the pitch of the lenticular lens shape. 2. A have your <br/> the transmissive screen according to claim 1, a transmissive screen in which the colored layer is characterized in that has a shape along the lens shape. 3. The transmission type switch according to claim 1 or 2 .
In a clean screen , the colored layer is formed along a path of total reflection light. 4. The transmissive screen as claimed in any one of claims 3, wherein the colored layer is transmissive, wherein the thickness is less than 1/2 of the sheet thickness Screen . 5. The transmission screen according to claim 1, wherein the lenticular lens shape of the lens portion is substantially elliptical in cross section, the horizontal diameter is a, and the vertical diameter is a. when was is b, the thickness t1 of the colored layer at the top of the lenticular lens shape is substantially ^{t1 = b-b 2 / (} a 2 + b
² ) A transmission-type screen characterized by being expressed by the formula of ^1/2
Or In the transmission type screen as set forth in claim 6] claim 1 in any one of claims 5, at least the colored layer, the transmissive screen, characterized in that the diffusion agent is added. 7. The transmissive screen according to claim 6, wherein the concentration of the diffusing agent mixed in the colored layer is C1, and the concentration of the diffusing agent mixed in the base layer is C0. Sometimes 0 ≦ C0
< Transmissive screen characterized by satisfying C1. 8. The transmission screen according to claim 1, wherein the coloring layer is not mixed with a diffusing agent, and the base layer is not colored or A transmission layer characterized by being provided with a diffusion layer formed between the coloring layer and the base layer and mixed with a diffusing agent.
Type screen . 9. The transmissive screen according to claim 1, wherein the lenticular lens shape is such that a tangent of the lenticular lens has an angle greater than a critical angle with respect to the lenticular lens sheet surface. Transmission screen characterized by containing
N. 10. The transmissive screen as claimed in any one of claims 9, wherein the substrate layer is transmissive screen that light exit surface, characterized in that a flat surface or a mat surface . 11. The transmission screen according to claim 10, wherein the base material layer has an antireflection layer, a low reflection layer, a polarizing filter layer, an antistatic layer, and an antiglare treatment layer on the light emitting surface. And a transmission screen , wherein at least one of the hard code processing layers is formed. 12. The method according to claim 1, wherein :
The transmission screen according to claim 1 , further comprising a display front plate disposed on an observation side of the lenticular lens sheet. 13. The transmissive screen according to claim 12 , wherein the front panel for a display has a base layer, and a lens portion having a lenticular lens shape formed in a convex shape on a light incident surface of the base layer. And a colored layer formed at least in the vicinity of the light incident surface of the lens part, wherein the light emitting surface of the base layer is a flat surface or a mat surface. 14. The transmission screen according to claim 13 , wherein the base layer has an antireflection layer, a low reflection layer, a polarizing filter layer, an antistatic layer, an antiglare treatment layer, and a hard coat treatment on a light exit surface. A transmission screen, wherein at least one of the layers is formed. 15. The transmissive screen according to any one of claims 1 to 14, a transmission screen which total light transmittance is characterized in that 40 to 70%.