WO2004104693A1

WO2004104693A1 - Projection screen and method of manufacturing thereof

Info

Publication number: WO2004104693A1
Application number: PCT/IB2003/003096
Authority: WO
Inventors: Anton A. Dremlyuga; Andrey V. Kokhanov; Vladimir A. Kokhanov
Original assignee: Dremlyuga Anton A; Kokhanov Andrey V; Kokhanov Vladimir A
Priority date: 2003-05-26
Filing date: 2003-05-26
Publication date: 2004-12-02
Also published as: EA200501862A1; EA009996B1; AU2003304149A1

Abstract

The invention relates to projection-type apparatus and to projection screens, in particular, and is intended for use in TV projection systems both for household applications and for large viewing halls as well as other public facilities. Also filed is a method of manufacturing such screens. An easy to manufacture and to use projection screen with enhanced contrast and brightness comprises a substrate (1) and a film (2) applied thereon, said film (2) containing first particles (4) varying the direction of light propagation without light absorption. The film (2) may present in itself from one to thirty layers (3) of transparent material, wherein said first particles (4) are concentrated on the surface of each layer (3) facing said substrate (1). The substrate (1) may be made both transparent and reflecting as well as rigid or flexible. During the manufacturing of the screen (6) the layers of transparent material solution with uniformly distributed first particles (4) are applied on the substrate (1), while said first particles (4) are precipitated on the layer surface facing said substrate during the process of hardening of each layer (3).

Description

PROJECTION SCREEN AND METHOD OF MANUFACTURING THEREOF

FIELD OF THE INVENTION

The invention relates to projection-type apparatus, and to projection screens in particular, and is intended for use in TV projection systems both for household applications and for large halls, auditoriums (viewing halls) as well as other public facilities. Also filed is a method of manufacturing such screens.

BACKGROUND OF THE INVENTION

The state of projection technique at present is subject to rapid growth. In connection with this a great number of various screens are known including an ordinary sheet of white material used as the screen as well as rather sophisticated multi-layered structures with the absorbing and dissipating layers [JP 3103802 B2, IPC 7: G 03B 21/62, published 30.10.2000] and the layers of the Fresnel lens [JP 3043485 B2, IPC 7: G 03B 21/62, published 22.05.2000; JP 3031804 B2, IPC 7: G03B 21/62, published 10.04.2000].

The screens not equipped with the Fresnel lens are characterized by a wide viewing angle; however, a substantial "hot spot" effect, i.e. non-uniform brightness distribution throughout the screen area features such screens.

As opposed to the above, the screens equipped with the Fresnel lens as one of the layers are characterized by a marked decrease of a "hot spot" effect, but the viewing angle of such screen is also considerably lessened.

The known screen and method of manufacturing described in [JP 2769518 B2, IPC 7: G 03B 21/62, published 25.06.1998] are the most closely related references to the claimed screen and method.

A projection screen described in [JP 2769518] comprises a substrate and a dye film applied thereon, said dye film containing the particles uniformly distributed therein, said particles varying the direction of light propagation without light absorption. Such screens are manufactured by application on a substrate of a dye film containing the particles uniformly distributed therein, said particles varying the direction of light propagation without light absorption. The screens of the type described above are rather simple in design, such screens however do not provide the required contrast and brightness.

SUMMARY OF THE INVENTION

Therefore it is the aim of the present invention to design a screen with enhanced brightness and contrast which is easy to manufacture and to use, as well as an inexpensive and fast method of manufacturing such screens.

The aim set forth in a projection screen comprising a substrate and a film applied thereon, said film containing first particles varying the direction of light propagation without light absorption, is achieved by means of said film presenting in itself at least one layer of transparent material with said first particles being concentrated on the surface facing said substrate.

The film may be comprised of 2 to 30 layers.

The substrate can be made both transparent and reflecting, and either rigid or flexible. To meet these requirements the substrate is to be made either of plastic or glass.

The layers of said film may be lacquer-made.

The first particles preferably have the dimensions varying from 3 to 11 μm and may be both the particles of transparent amorphous substance, glass in particular, and the transparent or reflecting crystals.

If required the film may contain uniformly distributed light-dissipating second particles, which may be color pigment particles e.g. black ones.

In a method of manufacturing of a projection screen by means of making a film on a substrate, said film containing first particles varying the direction of light propagation without light absorption, the aim set forth is achieved by means of applying on the substrate surface of at least one layer of transparent material solution containing said first particles and precipitation of said first particles on the layer surface facing said substrate during the process of hardening of said layer, while the hardening time is chosen sufficient to provide precipitation of said first particles.

Preferably from 2 to 30 layers may be applied. Hardening of each layer can be performed alternatively by means of drying, polymerization or crystallization.

The process of hardening may be performed with the substrate being positioned horizontally for example.

The layers of said film can be possibly lacquer-made.

The first particles having the dimensions from 3 to 11 μm are pre-produced of transparent amorphous substance e.g. of glass, or either transparent or reflecting crystals are used as the above first particles.

If required the solution containing the material of film layers may be added with uniformly distributed light-dissipating second particles. Said second particles may be color pigment particles e.g. black ones.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig.l shows a cross-sectional view of an example of a screen structure as filed in its diagrammatic form.

Fig.2 shows an example of a screen as filed in assembly.

DETAILED DESCRIPTION AND MOST PREFERABLE EXAMPLES OF THE

INVENTION

The filed method of manufacturing of a screen as filed is comprised of the following steps:

i. Producing the material for manufacturing of film layers. The substrate material can be chosen from both rigid materials (glass, plexiglas etc., having the thickness from 2 to 20 mm, for example) and flexible materials (polyvinyl etc.).

The choice of reflecting material (such as polished sheet metal e.g: aluminium-lamellar, or metal films) as the substrate material makes possible the implementation of a reflecting-type screen. The material of the layers may be made of any transparent film-forming material in combination with an appropriate dissolvent, the above combination featuring the required adhesion to the substrate material chosen.

To manufacture a screen having the dimensions of 3x2 m the components required are as follows:

1. A transparent nitrolacquer;

2. An appropriate dissolvent.

Depending on the final purpose of the screen the required quantity of nitrolacquer mixed up with the dissolvent makes up from 10 to 30 liters.

3. First particles varying the direction of light propagation without light absorption and having the dimensions from 3 to 11 μm in the form of the particles of transparent amorphous substance, of glass in particular, or in the form of low- dispersion transparent or reflecting crystals. For example, the required- quantity of low- dispersion crystalline powder makes up from 200 gram to 2 kilogram.

4. Second particles in the form of color pigment (a black nitrodye could be chosen in the example). The quantity of nitrodye used makes up to 500 ml.

All of the above-mentioned components have to be mixed up to obtain the resulting homogeneous substance of the uniform color. ii. Applying the first and the subsequent layers and their successive hardening;

Applying the layers could be performed by means of a method employing a dye sprayer or an air compressor, and also by means of pouring, centrifugatiόn, dipping or any other appropriate means known to those skilled in the art.

Afterwards hardening in the form of drying, polymerization or crystallization of the first and each subsequent layers are carried out. Each subsequent layer is applied after partial or complete hardening of the preceding layer. During the period of partial hardening of each layer the first particles are precipitated on the substrate or for the second and subsequent layers on the surface of the preceding layer. The hardening time is chosen sufficient to provide precipitation of said first particles. iii. Final solidification of the film. To provide solidification of the screen the processes of drying, polymerization or crystallization could be used.

The implementation of a screen filed by a method filed can be supported by the following non-limiting examples.

EXAMPLE 1.

A poly vinyl sheet having the dimensions of 2x3 m with a non-transparent aluminium film glued to one of its surfaces was used as the substrate. The sheet was secured horizontally by any means known to those skilled in the art with the metal film facing upwards.

i. Producing the material for manufacturing of film layers.

Nitrolaque mixed up with the dissolvent was used in the quantity of 10 liters, low-dispersion crystalline powder in the quantity of 200 gram, black nitrodye in the quantity of 250 ml.

All of the above-mentioned components were mixed up at intensive stirring during 1 hr until the resulting homogeneous substance of the uniform color was obtained.

ii. Applying the first layer of a film.

A layer of the material pre-made as described above was applied on a substrate.

A method employing a dye sprayer or an air compressor was used as one of the easiest methods for application of the layers.

Afterwards hardening of the first layer was carried out. For the example described the layer was dried in the open air at the temperature of 25°C during 1,5 hrs. ^•

iii. Applying the subsequent layers of a film.

The second, third and forth layers were applied similar to the first layer. The layers were applied uniformly in turn with the layer thickness ranging from 0,5 to 1 mm.

Each subsequent layer was applied after complete drying of the preceding layer.

iv. Solidification of the finished screen

To provide solidification of the screen the process of drying was used as in the example described. Drying was carried out at the temperature of 40 °C during at least 24 hrs until complete solidification of all the layers applied during manufacturing of the screen was achieved.

The end result was the reflecting-type screen having the dimensions of 2x3 m, which could be rolled for convenient transportation. When in use the screens of the type could be secured in a vertical frame by any means known to those skilled in the art or hung up on the wall.

EXAMPLE 2.

The plexiglass sheet having the thickness 10 mm was used as transparent material in the example described. The plexiglass sheet was secured in horizontal position by any means known to those skilled in the art.

i. Producing the material for manufacturing of film layers.

The nitrolaque mixed up with the dissolvent was used in the quantity of 30 liters, low- dispersion crystalline powder in the quantity of 2000 gram, black nitrodye in the quantity of 500 ml.

All of the above-mentioned components were mixed up at intensive stirring during 1 hr until the resulting homogeneous substance of the uniform colour was obtained.

ii - iii. Applying the layers was provided similar to the description given in Example 1.

The number of the layers applied was 8.

Hardening of each layer was carried out. For the example described the layers were dried in the open air at the temperature of 60-70°C during 0,5hr.

The layers are applied uniformly in turn with the layer thickness ranging from 1 to 3 mm. Each subsequent layer was applied after partial or complete drying of the preceding layer.

iv. Solidification of the finished screen.

To provide solidification of the screen the process of drying was used in the example described. Drying was carried out at the temperature of 40 °C during at least 24 hrs until complete hardening of all the layers applied during manufacturing of the screen was achieved.

The end result was the rigid rear-projection screen having the dimensions of 2x3 m.

Fig.1 shows an example of a screen structure as filed in its diagrammatic form. The screen comprises a substrate 1 and a film 2 applied thereon. The film 2 is comprised of several layers, as for the example described of four layers 3. Each such layer 3 is made of transparent material and contains two types of particles i.e. first particles 4 varying the direction of light propagation without light absorption, and second particles 5 of light- dissipating type. Second particles 5 are uniformly distributed in the material layer 3, while first particles 4 are concentrated on the border of each layer facing the substrate 1. The transparent spatial gaps are formed between the layers of particles 4 in the screen.

In comparison to the previous models of screens, the screen as manufactured using several light-dissipating layers 3 is characterized by enhanced light-dissipating characteristics due to interaction of a flow of light with all dissipating layers in turn. A flow of light passing through light-dissipating layers 3 initiates an effect of multiple reflection and refraction of beams inside first particles 4, this resulting in enhanced glowing of the screen and improved distribution uniformity of the image brightness throughout the screen area.

This effect is initiated irrespective of whether the flow of light is supplied behind the screen passing through the substrate 1 and the layers 3 or supplied in front of the screen passing through the layers 3, reflecting from the substrate 1 and again passing through the layers 3.

The use of the dye for screen manufacturing makes it possible to achieve considerable darkening of the screen surface, thus resulting in the enhanced contrast of the image on the screen (black-to- white ratio).

The screen as manufactured may be installed for example in the manner shown in Fig.2. A screen 6 is secured in a steel frame 7. In the bottom part of the frame 7 there is a stand 8 for a light source with the mirror 9 being installed in the rear part of the frame 7 to direct said light onto the screen 6.

The screen as filed makes it possible¹: to achieve the aim of the invention due to its simplicity in manufacturing and use as well as to the characteristics that follow:

1. Enhanced brightness;

2. Enhanced contrast;

3. Improved uniformity of image brightness throughout the screen area.

Claims

1. A projection screen comprising a substrate and a film applied thereon, said film containing first particles varying the direction of light propagation without light absorption, wherein said film presents in itself at least one layer of transparent material with said first particles being concentrated on the surface facing said substrate.

2. A projection screen as in claim 1, wherein said film may be comprised of 2 to 30 layers.

3. A projection screen as in claim 1, wherein said substrate is made a transparent one.

4. A projection screen as in claim 1, wherein said substrate is made a reflecting one.

5. A projection screen as in claim 1, wherein said substrate is made a rigid one.

6. A projection screen as in claim 1, wherein said substrate is made a flexible one.

7. A projection screen as in claims 4-6, wherein said substrate is made of polished metal or metal film.

8. A projection screen as in claims 1-5, wherein said substrate is made of glass.

9. A projection screen as in claims 1-6, wherein said substrate is made of plastic.

10. A projection screen as in claims 1-9, wherein said layers of said film are lacquer-made.

11. A projection screen as in claims. 1-10, wherein said first particles have the dimensions ranging from 3 to 11 μm.

12. A projection screen as in claim 11, wherein said first particles are the particles of transparent amorphous substance.

13. A projection screen as in claim 12, wherein said first particles are the particles of glass.

14. A projection screen as in claim 11, wherein said first particles are transparent or reflecting crystals.

15. A projection screen as in claims 1-14, wherein second light-dissipating particles are uniformly distributed in the material of film layers.

16. A projection screen as in claim 15, wherein said second particles are the pigment particles.

17. A projection screen as in claim 16, wherein said pigment is a color one.

18. A method of manufacturing of a projection screen by means of making a film on a substrate, said film containing first particles varying the direction of light propagation without light absorption, wherein said film is made by means of applying- on the substrate surface of at least one layer of transparent material solution containing said first particles and precipitation of said first particles on the layer surface facing said substrate during the process of hardening of said layer, while the hardening time is chosen sufficient to provide precipitation of said first particles .

19. A method as in claim 18, wherein from 2 to 30 layers are applied thereon.

20. A method as in claim 19, wherein the process of hardening is performed with the substrate being positioned horizontally.

21. A method as in claims 18-20, wherein hardening of each of said layers is performed by means of drying.

22. A method as in claims 18-20, wherein hardening of each of said layers is performed by means of polymerization.

23. A method as in claims 18-20, wherein hardening of each of said layers is performed by means of crystallization.