Optical: systems and elements – Diffusing of incident light
Reexamination Certificate
1999-06-02
2001-10-02
Nguyen, Thong (Department: 2872)
Optical: systems and elements
Diffusing of incident light
C359S900000, C349S064000, C362S035000
Reexamination Certificate
active
06297908
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a directional light-diffusing film that is mounted to a display surface of a liquid-crystal display or plasma display or the like for the purpose of preventing a reduction in frontal intensity and preventing parallax, to a method of manufacturing the above-noted directional light-diffusing film, and to a display that uses this directional light-diffusing film.
2. Description of the Related Art
In the past, in a display such as a reflective-type liquid-crystal display as noted above, a light-diffusing film was mounted for the purpose of preventing a reduction in the frontal intensity of the display screen and preventing parallax.
This light-diffusing film was, for example, a resin sheet (film) that had surface unevenness and that included a light-diffusing substance, or was a resin sheet over which a light-diffusing layer having surface unevenness and including a light-diffusing substance was provided, so as to diffuse the light exiting from the display surface.
In the above-noted types of light-diffusing films that is a resin sheet over which a light-diffusing layer having surface unevenness and including a light-diffusing substance is provided, there are film types that have extremely small surface unevenness, which mainly use the diffusion effect of internal diffusion within the light-diffusing layer.
Because a lens film also has the same type of effect as a light-diffusing film, there are cases in which it is used in the application of a light-diffusing film.
Additionally, there is a louver film that is similar to the above-noted lens film and light-diffusing film. This louver film absorbs oblique external light and has the effect of improving frontal contrast.
While the above-noted type of light-diffusing film and lens film can improve the frontal intensity and parallax by diffusion of transmitted light, the light-diffusion effect thereof increases the scattered reflections of external light, thereby causing a significant decrease in contrast, or a tendency for an image formed by pixels on the display screen to appear out of focus.
With a light-diffusing film that mainly uses internal diffusion, it is possible to reduce the reflection of external light in comparison with the usual light-diffusing film. However, with such a light-diffusing film there is an increase in the diffusion of image light, the result being the defocusing of the image is greater than with a usual light-diffusing film.
With the above noted louver film, oblique external light is absorbed, and there is the effect of improving the frontal contrast. However, because there is no effect of diffusing transmitted light, it is not possible with this type of film to achieve an improvement in intensity and parallax.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention, in consideration of the above-noted drawbacks in the prior art, to provide a directional light-diffusing film that can improve the image defocusing without sacrificing the function of preventing an excessive reduction in frontal intensity and preventing parallax, to provide a method for manufacturing the above-noted directional light-diffusing film, and to provide a display that uses the above-noted directional light-diffusing film.
To achieve the above-noted object, the present invention is a directional light-diffusing film that is configured with minute light-transmitting regions that pass light in the thickness direction and minute light-diffusing regions that diffuse light in the thickness direction, these regions being arranged in an alternating manner and without space therebetween in either the direction of one dimension or the directions of two dimensions, on at least one surface of the front and rear surfaces of a transparent base material film.
The above-noted light-diffusing regions can have a polygonal cross-section in a cutting direction that is perpendicular to the front surface or the rear surface.
In the above-noted directional light-diffusing film, the light-diffusing regions and the light-transmitting regions can be configured in parallel lines arranged in an alternating manner.
Additionally, the above-noted light-diffusing regions can be made by including a light-diffusing substance in a transparent resin.
It is also possible to have the border between the above-noted light-diffusing regions and light-transmitting regions be an uneven surface in which a minute depression and protrusion are formed.
In the above-noted directional light-diffusing film, it is possible to use the above-noted light-transmitting regions as either convex lenses or concave lenses.
In the above-noted directional light-diffusing film, it is additionally possible to cover the outside of the above-noted light-diffusing regions and light-transmitting regions with an anti-reflective layer.
In the above-noted directional light-diffusing film, it is also possible to further provide a light-transmitting adhesive layer on at least one surface of the front and rear surfaces.
In the above-noted directional light-diffusing film, it is also possible to laminate a polarizer onto at least one of the above-noted front surface and rear surface.
In the above-noted directional light-diffusing film, it is also possible for the above-noted polarizer to be a polarizer on a surface of a liquid-crystal display.
It is additionally possible in the above-noted directional light-diffusing film to form the light-transmitting regions using a light-transmitting resin.
In the above-noted directional light-diffusing film, it is also possible to have the light-transmitting regions be voids.
As related to a display device, the present invention achieves the above-noted object by virtue of a configuration having a display panel that displays an image by means of pixels, and a directional light-diffusing film such as described above, which is laminated onto the display surface of this display device.
In the above-noted display, it is possible to adhere the above-noted directional light-diffusing film onto the display panel via an intervening light-transmitting adhesive layer.
Additionally, in the case of the above-noted display panel being a liquid-crystal display panel, it is possible to adhere the above-noted directional light-diffusing film to the display side polarizer of the liquid-crystal display panel, via an intervening light-transmitting adhesive layer.
A method of manufacturing a directional light-diffusing film that achieves the above-noted object is one whereby a directional light-diffusing film that is configured with minute light-transmitting regions that pass light in the thickness direction and minute light-diffusing regions that diffuse light in the thickness direction, these regions being arranged in an alternating manner and without space therebetween in either the direction of one dimension or the directions of two dimensions, on at least one surface of the front and rear surfaces of a transparent base material film is manufactured, this method having a step of causing a roller die, which is formed so as to have intermittently formed in it shape-imparting depressions along its outer periphery, to rotate, while applying a fluid resin into the depression parts of a roller die, and while a transparent resin film is wound around the outside of the roller die and caused to come into contact with the resin inside the above-noted depressions, a step whereby, during rotation of the above-noted roller die, resin inside the above-noted shape-imparting depressions is caused to come into intimate contact with the transparent base material film and caused to be hardened, thereby forming either a light-diffusing region or a light-transmitting region, and a step of peeling both the hardened resin and the transparent base material film from the roller die.
In the above-noted method of manufacturing a directional light-diffusing film, after the above-noted peeling step, there can be a step of filling the between the hardened resin that forms the light-diffusing region or ligh
Dai Nippon Printing Co. Ltd.
Nguyen Thong
Oliff & Berridg,e PLC
LandOfFree
Directional light-diffusing film, a method of manufacturing... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Directional light-diffusing film, a method of manufacturing..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Directional light-diffusing film, a method of manufacturing... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2603599