JPH03120503A - Polarizing component - Google Patents

Abstract

PURPOSE:To take out linearly polarized light without generating heat by holding a parallel flat plate in which a thin film to separate incident light to P- and S-polarized light is provided at a plane on one side of a container comprised of an optically transparent material and filling liquid in the container. CONSTITUTION:A thin film multilayer film 2 which separates the incident light to the P- and S-polarized light is provided at the parallel flat plate 1, and it is housed in the optically transparent container 3, and the liquid 4 such as ethylene glycol, silicone gel, etc., is filled in the container 3. The parallel flat plate 1 is held with the container 3, and the liquid 4 is sealed in the container 3 so as not to leak. When natural light is made incident from the right side, it transmits the container 3, and transmits the liquid 4, then, it is made incident on the multilayer film 2, and all the P-polarized light transmits it, and most of the S-polarized light are reflected. Transmitting P-polarized light transmits the liquid 4, and can be taken out outside a polarizing component passing the container 3. Therefore, it is possible to take out the linearly polarized light without generating heat with an inexpensive material.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a polarizing component used in an optical system using polarized light, such as a polarizer for a liquid crystal projector.

Conventional technology Conventionally, in order to obtain linearly polarized light from natural light or circularly polarized light,
Polarizing plates and polarizers made of crystals that exhibit birefringence are used.

Problems to be Solved by the Invention However, when a cheap and commonly used polarizing plate receives natural light, it absorbs 50% of the light and generates heat on its own.
The temperature of the polarizing plate increases. However, polarizing plates are sensitive to temperature rises (and when used in a system with a large amount of light, the characteristics of the polarizing plate deteriorate. There are prisms made of glass, polarizing beam splitters made of glass, etc., but they are both expensive and have the problem of being thick (and large).

The present invention aims to solve such conventional problems, and aims to provide an inexpensive polarizing component that does not generate heat and can extract linearly polarized light from natural light or circularly polarized light. It is something to do.

Means for Solving the Problems The polarizing component of the present invention comprises a parallel plane plate provided on one side with a thin film that separates incident light into P-polarized light and S-polarized light, and the parallel plane plate made of an optically transparent material. A container that holds a face plate and a liquid that fills the container, a parallel plane plate is placed in the container, and the container is filled with the liquid.Incoming natural light is divided into P polarized light and S polarized light. The light is separated into polarized light, with the P-polarized light passing through the thin film and the S-polarized light being reflected by the thin film. Polarized light can be obtained directly by extracting the transmitted P-polarized light or the reflected S-polarized light.

Effect Generally, when a light ray enters a substance with a different refractive index, if the angle between the normal to the boundary surface of the substance and the incident light is the angle of incidence, then if the angle of incidence is other than 0 degrees, the light will be P It is divided into polarized light and S-polarized light, each exhibiting different transmittance and reflectance. When the incident angle is increased, the reflectance of P-polarized light decreases and the reflectance of S-polarized light increases.

If the incident angle is set to Brewster's angle, the reflection of P-polarized light becomes 0, and only S-polarized light is reflected. The transmitted light includes not only P-polarized light but also S-polarized light. In order to transmit only P-polarized light, it is sufficient to stack films with two types of refractive index under the condition that all P-polarized light is transmitted.

Natural light incident on the polarizing component of the present invention passes through the container,
It passes through the liquid and enters the thin film. Here, all of the P-polarized light is transmitted, and most of the S-polarized light is reflected.

The transmitted P-polarized light can be transmitted through the liquid, transmitted through the container, and taken out of the polarizing component. Therefore, according to the present invention, it is possible to extract linearly polarized light without generating heat using inexpensive materials.

EXAMPLE Hereinafter, a polarizing component according to an example of the present invention will be described with reference to the drawings. FIG. 1 shows a plan cross-sectional view of a polarizing component according to a first embodiment of the present invention.

In FIG. 1, l is a parallel plane plate, 2 is a thin multilayer film provided on the parallel plane plate 1 and separates incident light into P-polarized light and S-polarized light, 3 is an optically transparent container, and 4 is a Liquids such as ethylene glycol and silicone gel. parallel plane plate l
is held by container 3. The liquid 4 is sealed by the container 3 so as not to leak. Natural light incident from the right side is transmitted to the multilayer film 2. Multi [S by 112
Polarized light is reflected and P-polarized light is transmitted.

FIG. 2 shows a plan sectional view of a polarizing component according to a second embodiment of the present invention. In the embodiment shown in FIG. 2, a plurality of parallel plane plates 1 are installed in a container 3.

According to this configuration, the length in the optical axis direction can be shortened, and the first
The same effect as shown in the figure can be obtained.

FIG. 3 shows a plan sectional view of a polarizing component according to a third embodiment of the present invention. In FIG. 3, 5 is a thermosetting or photocurable silicone gel, and the difference from FIG. 1 is that this material If the silicone gel 5 is injected and cured during assembly, it can be brought into close contact with the multilayer film 2, parallel plane plate 1, and container 3, and there is no fear of liquid leakage after assembly.

FIG. 4 shows a plan sectional view of a polarizing component according to a fourth embodiment of the present invention. In FIG. 4, 6 is a part of the container 3, which is a member painted black so as to absorb light. That is, in FIG. 4, a member 6 that absorbs light is provided except for the entrance surface and the exit surface, and it is possible to prevent the reflected S-polarized light from leaking to the outside.

FIG. 5 shows a fifth embodiment of the present invention used in a liquid crystal projector. In FIG. 5, 7 is a projection lens, 8 is a polarizing plate, 9 is a liquid crystal panel, IO is a condenser lens,
11 is a light source. Natural light emitted from the light source 11 becomes parallel light by the condenser lens IO, becomes linearly polarized light by the polarizing component of the present invention, is polarized by the liquid crystal panel 9 according to the image, and is converted by the polarizing plate 8 into light amplitude according to the image. be done. The image is enlarged and projected by a projection lens 7.

According to this configuration, there is no need to use a polarizing plate in areas where the amount of light is large, and reliability is improved.

FIG. 6 shows a sixth embodiment of the present invention used in a liquid crystal projector. In FIG. 6, 12 is a polarizing plate.

In addition to the polarizing plate 8, the accuracy of polarization can be increased by placing a polarizing plate 12 in the optical path.Since most of the light is converted into linearly polarized light by the polarizing component of the present invention, the burden on the polarizing plate 12 is small and the temperature rise is reduced. There is also little deterioration in the characteristics of the polarizing plate 12 due to temperature rise.

Effects of the Invention As described above, according to the present invention, it is possible to provide a polarizing component that can extract linearly polarized light without generating heat using inexpensive materials.

[Brief explanation of drawings]

FIG. 1 is a sectional plan view of a polarizing component according to a first embodiment of the present invention, FIG. 2 is a sectional plan view of a polarizing component according to a second embodiment of the present invention, and FIG. FIG. 4 is a cross-sectional plan view of a polarizing component according to an embodiment of the present invention; FIG. 4 is a cross-sectional plan view of a polarizing component according to a fourth embodiment of the present invention; FIG. FIG. 6 is a schematic diagram showing a sixth embodiment of the present invention used in a liquid crystal projector. l...Parallel plane plate, 2...Ilg provided on parallel plane plate 1, 3...Container, 4...
...Liquid, 5...Thermosetting or photocurable silicone gel, 6...Member painted black to absorb light, 7...・Projection lens, 8
．． 12...Polarizing plate, 9...Liquid crystal panel, lO...Condenser lens, ll...
··light source.

Claims (1)

[Scope of Claims] (1) A plane-parallel plate having a thin film on one side that separates incident light into P-polarized light and S-polarized light, and a container for holding the plane-parallel plate, which is made of an optically transparent material. and a liquid filling the container, a parallel plane plate is placed in the container,
A polarizing component characterized in that the container is filled with the liquid described above. (2) The polarizing component according to claim 1, having a plurality of folded portions formed by a plurality of parallel plane plates. (3) The polarizing component according to claim 1, wherein a silicone gel that is cured by heat or light is used as the liquid filling the container. (4) The polarizing component according to claim 1, wherein the container is made of a material that absorbs light except for the entrance surface and the exit surface. (5) A polarizing component used in a polarizer that converts natural light from a light source into linearly polarized light in a liquid crystal projector that enlarges and projects an image on an upper liquid crystal plate by passing incident light from a light source through a liquid crystal plate, a polarizing plate, and a lens. (6) The polarizing component according to claim 4, wherein the polarizing component is used in combination with a polarizing plate and is placed on the incident side of the polarizing plate.