JP2003270727A - Transmission screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive transmission screen consisting of the lenticular lenses and Fresnel lenses kept tightly stuck to each other even under the environment of a high temperature and high humidity and having an excellent resolution. <P>SOLUTION: The transmission screen consisting of a lenticular lens sheet 21 having light shielding patterns 22a and a Fresnel lens sheet 22, in which at least either of the lenticular lens sheet 21 or the Fresnel lens sheet 22 is made flexible by forming lens sections of a UV curing resin on a base material film of polyethylene terephthalate or polycarbonate. The transmission screen is formed by firmly sticking the lenticular lens sheet and the Fresnel lens sheet and integrally fixing both the sheets with an outer frame existing in a peripheral part. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmissive screen used in a projection type projection television or the like.

[0002]

2. Description of the Related Art As a conventional transmissive screen, a CRT is used.
A transmissive screen, which is mainly used for a projection television and the like, has conventionally used a double-sided lens manufactured by extrusion molding or the like. It is difficult to make the screen made by this method fine with a lenticular lens pitch of 0.3 mm or less on both sides, and it will be moistened in liquid crystal projection TVs using high definition panels compatible with digital high definition (HDTV) images. There are limits in terms of resolution, etc.

Recently, a liquid crystal projection television using a high-definition panel corresponding to this digital high-definition image has emerged, and a liquid crystal projection screen provided with a fine lenticular lens and a high-density black stripe has been developed. It has been put to practical use. This LCD projection screen uses a high-definition panel that is compatible with digital high-definition (HDTV) images because it has a wide viewing angle, high resolution, and high contrast because it has a finer lens and a high-density black stripe. Even on the LCD projection TV, the moire is not noticeable and a clear image is projected by the liquid crystal projection.

The present inventors have further investigated the vertical viewing angle by CRT.
-In addition to a lenticular lens in order to bring it closer to a TV, a microlens is proposed as a new optical element, and a higher performance screen is proposed. However, most of these screens are mainly made of acrylic resin such as PMMA (polymethylmethacrylate) or acrylic resin such as MS resin (methylmethacrylic-styrene copolymer resin) due to the rigidity, transparency and cost of the screen. To be done.

Among these acrylic resins, the elongation of the resin is particularly large when absorbing moisture, and high temperature and high humidity (60 ° C., 90% R
H) The effect is remarkable under the environment. When such elongation is large, since the outer periphery of the screen mounting is fixed by a mounting jig, both the lenticular lens and the Fresnel lens swell due to expansion, and the space of the contact portion between them expands, resulting in image blurring and This leads to a decrease in resolution.

In order to prevent this, there is also a method of increasing the adhesion by bending the wrench fresnel to the opposite side to each other. However, this method of adding a warp increases the number of steps and makes it difficult to control the warp. There is.

[0007]

SUMMARY OF THE INVENTION The present invention is intended for high definition (HDTV) broadcasting such as liquid crystal or DLP (using a mirror device developed by Texas Instruments Inc., USA) projection type projection television. In order to provide a transmissive screen for the purpose of projecting high-resolution and high-definition images, we provide a transmissive screen that is cheaper and maintains the adhesion between the lenticular lens and Fresnel lens even in a hot and humid environment and has excellent resolution. That is.

Specifically, a self-luminous display such as a direct-view CRT television or a PDP is provided by improving the drawbacks of the projection system which has a higher resolution and a wider viewing angle, and more particularly, a vertical viewing angle, which is conventionally dependent on the viewing angle. The purpose is to get closer to. Moreover, in order to further popularize it as a television, it is possible to manufacture it at a relatively low cost.

[0009]

That is, the invention according to claim 1 is a Fresnel lens sheet having a function of emitting projection light from a projector as substantially parallel light to a lenticular lens sheet arranged on the observation side, Cylindrical lenses are arranged in parallel on one surface, and a stripe-shaped light-shielding pattern and a light diffusion layer in which a portion corresponding to a light condensing portion by each cylindrical cylinder lens is an opening are formed on the other surface,
Outgoing light from the Fresnel lens sheet, by the function of the cylindrical lens and the light diffusing layer, in a transmissive screen consisting of a lenticular lens sheet having a function to spread and emit as display light, the lenticular lens sheet and the Fresnel lens sheet At least one is a polyethylene terephthalate, on the substrate film of polycarbonate, the lens portion is formed of an ultraviolet curable resin is a flexible structure, and the lenticular lens sheet and Fresnel lens sheet are in close contact with each other, the peripheral portion. It is a transmissive screen characterized in that it is integrally fixed by a positioned outer frame.

According to a second aspect of the present invention, the Fresnel lens sheet having a function of emitting the projection light from the projector as substantially parallel light to the microlens sheet arranged on the observation side, and the unit lens on one side are two. It has a microlens array part that is arranged in a substantially dimensional array, and on the other surface, a light-shielding pattern and a light-diffusing layer whose openings are the light-collecting parts of individual unit lenses are formed. In the transmissive screen consisting of a microlens sheet having a function of spreading and emitting the emitted light as display light by the function of the microlens array portion and the light diffusion layer, at least one of the microlens sheet and the Fresnel lens sheet is UV curing on polyethylene terephthalate and polycarbonate base films It is a flexible structure in which a lens portion is formed of resin, and is characterized in that the microlens sheet and the Fresnel lens sheet are brought into close contact with each other and integrally fixed by an outer frame located in the peripheral portion. It is a transmissive screen.

According to a third aspect of the present invention, the light-shielding pattern is formed of a photosensitive resin layer in which a condensing portion / non-condensing portion is defined according to the condensing characteristics of the cylindrical lens or the microlens array portion. The transmissive screen according to claim 1, wherein the transfer screen is formed by transferring a black transfer layer with a transfer sheet having a black transfer layer on the surface of the non-light-collecting portion.

The invention according to claim 4 is the transmissive screen according to any one of claims 1 to 3, characterized in that a front plate is provided on the outermost surface on the observation side.

Further, the invention according to claim 5 is characterized in that at least one surface treatment layer selected from a hard coat, an antistatic layer and an antireflection layer is provided on the observation surface side of the front plate. It is the transmissive screen according to claim 4.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. As shown in FIG. 1, an image is reflected from a projector (11) such as a liquid crystal display or a CRT to a reflection mirror (12,
The image formed by being reflected by 13) and being incident on the transmissive screen (20) from the back side is viewed from the front side. This transmissive screen (20) uses a Fresnel lens sheet (21) and a lenticular lens sheet (22) by an optical process to form a black stripe (22a) formed on a flat side and a diffusion layer (22b) on an emission surface. ) With a lenticular lens (22).

The Fresnel lens (21) makes the light projected from the incident light uniform on the entire screen, so that the light from the incident light is collimated and emitted to the lenticular lens.

The Fresnel lens (21) is manufactured as follows, as shown in FIG. The surface of a Fresnel lens mold (40) that has been optically designed and machined in advance is coated with an ultraviolet curable resin (hereinafter referred to as UV resin) and has a polyethylene terephthalate (PET) or polycarbonate (PC) base of about 200 μ. The material sheets (21a) are superposed, and ultraviolet rays are irradiated from the sheet surface to cure the lens surface of the UV resin. Next, when this is peeled from the mold, a sheet-shaped Fresnel lens sheet (2
1) is formed. Since this step is repeated in actual mass production, it is possible to obtain a rolled Fresnel lens in addition to the sheet-shaped one. Finally, this is cut into a predetermined size (screen size).

Next, the lenticular lens sheet and the microlens sheet are manufactured as follows. For liquid crystal projection TVs that use high-definition panels that support digital high-definition (HDTV) images, the lenticular has a pitch of 0.2 mm or less, and the microlens has a pitch of 0.1 mm or less to reduce pixel moire and improve resolution. Prepare a mold that has been processed as described above, coat the mold surface with UV curable resin (UV resin), and PET or PC on top of it.
The base sheets such as are stacked and handled with a roll to make the UV resin uniform on the front surface. After that, ultraviolet rays are cured from the sheet, and the lens is solidified and then peeled from the mold. The process up to here is the same as the process for forming the Fresnel lens sheet, which is the lens forming process for forming the lens substrate.

Next, a black stripe (hereinafter referred to as BS) or a black matrix (hereinafter referred to as BM) is formed in order to improve contrast and prevent reflection of external light. At this time, a method of forming BS or BM by the optical method shown in FIG. 3 is used as a method of forming high-concentration and high-fine BS or BM.

This is the incident side lenticular lens or microlens (incident lens A) formed in the previous step.
(23) is coated on the opposite surface of the lens with a sensitive material (25) having an adhesive property, and the lens A is formed by parallel light exposure.
The part of (23) where the light is transmitted and collected is the non-adhesive part (25
A), a non-transparent part that does not collect light and an adhesive part (2
5B) to form a sticky / non-sticky pattern.
(See FIGS. 3 (a) and 3 (b))

By using a transfer foil (40) having a black transfer layer (41) precoated on this portion and transferring the black ink only to the adhesive portion, only the non-light-collecting portion synchronized with the lens A is transferred. BS (22a) or BM can be formed on the substrate. (See FIGS. 3 (c) and 3 (d))

In this way, a perspective view of a screen configuration in which a lenticular lens sheet having a BS (black stripe) and a BM (black matrix) formed thereon and a Fresnel lens sheet, and a microlens sheet and a Fresnel lens sheet are combined is illustrated. 4 shows. Figure 4
Since (a) uses a lenticular lens, it has a stripe pattern, while FIG. 4 (b) has a circular pattern because it uses circular microlenses.

Next, a diffusion layer is formed on this BS or BM.

This diffusion layer is formed directly on the BS or BM, or on the transparent substrate such as PET by previously forming a diffusion layer in which a diffusion material such as an acrylic resin or an epoxy resin is dispersed or a minute microlens. A method is used in which the diffusion film having the diffusion layer is formed on the BS or BM with an adhesive material or an adhesive material. In addition, these diffusion layers are not affected by external scratches or abrasion, and thus B
It also serves as a protective layer for protecting the S or BM layer and the screen surface. Further, it is possible to impart an antistatic effect such as mixing an antistatic agent due to dirt due to electrification.

In the present invention, as a method for directly forming a diffusion layer on the BM, a resin binder such as acrylic or epoxy is mixed with a resin filler such as MS resin or acrylic, or a diffusing material such as an inorganic filler such as silica or silicon. Further, a diffusion resin layer or a diffusion layer formed by lenses such as micro lenses is formed.

In addition to the method of directly forming a diffusion layer on a BM, a diffusion layer in which a diffusion material such as an acrylic resin or an epoxy resin is dispersed and a minute microlens are formed and molded on a transparent substrate such as PET in advance. It is also possible to use a method in which the diffusion film having the diffusion layer is formed on the BM by sticking it with an adhesive material or an adhesive material. Further, this diffusion layer may be provided on the front plate provided with the outermost layer on the observation side.

For the purpose of protecting the lenticular lens and the microlens, a transparent resin substrate having a thickness of 3 mm or less such as acrylic resin, MS resin or polycarbonate resin is used as a front plate for the purpose of protecting it from scratches from the outside of the observation surface or pressure kelps. May be used. Since this front plate is closest to the observation surface, the antistatic effect of mixing an antistatic material into these diffusion layers to prevent electrostatic charges and the hard coat effect of increasing the surface hardness to prevent deterioration due to scratches and external light reflection It is more effective to simultaneously provide an AG (anti-glare) effect for reduction.

By the way, finally, the lenticular screen or the microlens screen on which the BS or BM is formed is cut into a predetermined size. Since the screen made here is a thin sheet of flexible screen and is not self-supporting as it is, as shown in FIG. 5, a screen fitted to an outer peripheral frame formed of highly rigid metal or resin. To make it a self-sustaining structure.

[0028]

Since the transmission screen of the present invention is composed of a sheet-shaped Fresnel lens and a lenticular lens or a Fresnel lens, it is less warped than a plate-shaped one and can be manufactured at low cost. Further, by providing the diffusion layer on the emission surface, it is possible to widen the viewing range and reduce the reflection of external light.

Further, since the conventional screen is made of a material such as acrylic having a large hygroscopic property and a large elongation due to the large hygroscopic property, the elongation under a high-temperature and high-humidity environment is large, resulting in a reduction in resolution. On the other hand, the transmissive screen of the present invention uses PET as a base material.
Because the base material is a sheet base material that does not stretch easily due to heat resistance and moisture absorption resistance such as PC and PC, it has excellent adhesion without stretching or bending even in such an environment, and a warp process to give adhesion The result is a screen with stable quality and low cost.

Further, BS or BM is formed by an optical process using a lenticular lens or a microlens which is actually used as a transmission type screen, and P is used as a base material.
Digital HD in the future by using a sheet base material with low elongation due to heat resistance and moisture absorption resistance such as ET and PC
As a screen of a liquid crystal projection type television (LCD-PJTV) or a DLP projection type television for high-definition images such as TV broadcasting, by providing a screen with excellent flexibility and low resolution even under a hot and humid environment at low cost. This will be supported by the widespread use of large-sized televisions that replace conventional CRT direct-view tubes.

[Brief description of drawings]

FIG. 1 illustrates a transmissive screen,
(A) shows an example of a projection type TV, (b) is a figure which shows typically the optical path to watch.

FIG. 2 is a diagram illustrating a method of producing a Fresnel lens sheet.

FIG. 3 is a diagram illustrating a method of forming a BS or BM.

FIG. 4A is a perspective view of a screen configuration in which a BS (black stripe) -formed lenticular lens sheet and a Fresnel lens sheet are combined, and FIG.
[Fig. 3] is a perspective view of a screen configuration in which a microlens sheet having a BM (black matrix) formed thereon and a Fresnel lens sheet are combined.

FIG. 5 is a diagram showing a state in which the transmissive screen is fixed by a frame.

[Explanation of symbols] 11 ... Projector 12, 13 ... Reflective mirror 20 ... Transparent screen 21 ... Fresnel lens sheet 21a ... Base sheet 21b ... lens part 22 ... Lenticular lens sheet 22a ... Black stripe 22b ... Diffusion layer 23 ... Lens part 24 ... Base sheet 25 ... Sensitive material 25A ... Non-adhesive part 25B ... Adhesive part 26 ... Black stripe 30 ... Mold 40 ... Transfer foil 41 ... Transfer layer 42 ... Transfer foil substrate

Claims (5)

[Claims] 1. A Fresnel lens sheet having a function of emitting projection light from a projector to a lenticular lens sheet arranged on the observation side as substantially parallel light, and a cyrindrum lens arranged in parallel on one surface, and the other surface on the other surface. A striped light-shielding pattern and a light diffusing layer whose openings correspond to the light condensing portion by the individual cylindrical lenses are formed, and the light emitted from the Fresnel lens sheet is processed by the functions of the cylindrical lens and the light diffusing layer. In a transmissive screen including a lenticular lens sheet having a function of spreading and outputting as display light, at least one of the lenticular lens sheet and the Fresnel lens sheet is polyethylene terephthalate,
On a substrate film of polycarbonate, a flexible structure in which a lens portion is formed of an ultraviolet curable resin,
A transmissive screen characterized in that a lenticular lens sheet and a Fresnel lens sheet are brought into close contact with each other and integrally fixed by an outer frame located in the peripheral portion. 2. A Fresnel lens sheet having a function of emitting projection light from a projector as substantially parallel light to a microlens sheet arranged on an observation side, and unit lenses are arranged two-dimensionally in a matrix on one side. And a light-diffusing layer in which a light-diffusing layer having an opening at a light-collecting portion formed by individual unit lenses is formed on the other surface of the microlens array. In a transmissive screen including a microlens sheet having a function of spreading and emitting as display light by the function of the light-diffusing layer and the light diffusion layer, at least one of the microlens sheet and the Fresnel lens sheet is a base film of polyethylene terephthalate or polycarbonate. The lens part was formed on the top with UV curable resin A transmissive screen having a flexible structure, in which a microlens sheet and a Fresnel lens sheet are brought into close contact with each other and integrally fixed by an outer frame located in a peripheral portion. 3. A light-shielding pattern is black-transferred onto the surface of the non-light-collecting part of a photosensitive resin layer in which the light-collecting part / non-light-collecting part is defined according to the light-collecting characteristics of a cylindrical lens or a microlens array part. The transmissive screen according to claim 1, wherein the transmissive screen is formed by transferring a black transfer layer with a transfer sheet having a layer. 4. The transmissive screen according to claim 1, further comprising a front plate provided on the outermost surface on the observation side. 5. The transmissive type according to claim 4, wherein at least one surface treatment layer selected from a hard coat, an antistatic layer and an antireflection layer is provided on the observation surface side of the front plate. screen.