JP2005326871A - Liquid crystal projector using dye system polarizing film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal projector, having superior durability by using a dye system polarizing film which is less deteriorated with respect to strong light from a light source. <P>SOLUTION: The liquid crystal projector has a light source system, a reflection/spectrum system, and a macroprojection system and is equipped with liquid crystal cells 7R, 7G, and 7B, light incident-side polarizing plates 8R, 8G, and 8B, and light exit-side polarizing plates 9R, 9G, and 9B, respectively in correspondence to red light R, green light G, and blue light B in the reflection/spectrum system. At least either the light incident-side polarizing plate 8B or the light exit-side polarizing plate 9B, through which the blue light B passes is constituted of the dye system polarizing plate, formed by laminating a protective plate on the at least one surface of the polarization film which is formed by subjecting a polyvinyl alcohol-based film to adsorption of a dichromatic dye and orientation and has an adsorption thickness of the dichromatic dye of ≥6 μm, in the section of the polyvinyl alcohol-based film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal projector using a dye-based polarizing film.

  Conventionally, a liquid crystal projector in which a liquid crystal display device called a video projector, a data projector, or the like is incorporated has three primary colors of light, that is, red (R), green (G), and blue (B) light beams of red light. A liquid crystal panel for green light, a liquid crystal panel for green light, and a liquid crystal panel for blue light are respectively irradiated to obtain images of respective primary colors, which are synthesized by a dichroic mirror or the like and projected.

  An outline of a general liquid crystal projector will be described with reference to FIG. 1. A liquid crystal projector usually has a light source system, a reflection / spectral system, and an enlarged projection system. The light source system includes a light source 11, a condensing lens 13, and a UV / IR cut filter 14. The white light L from the light source 11 is collected by the condensing lens 13, and further, UV is irradiated by the UV / IR cut filter 14. The infrared rays are cut and sent to the first dichroic mirror 1. As the light source 11, a metal halide lamp, a high-pressure mercury lamp, or the like is usually used.

  The reflection / spectral system includes four types of dichroic mirrors 1, 2, 3, and 4 and two total reflection mirrors 5 and 6, and liquid crystal cells 7R, 7G, and 7B corresponding to red light R, green light G, and blue light B, respectively. , Incident side polarizing plates 8R, 8G and 8B, outgoing side polarizing plates 9R, 9G and 9B, and condensing lenses 10R, 10G and 10B.

  The first dichroic mirror 1 transmits only the green light G and the blue light B, and the green light G and the blue light B transmitted therethrough are sent to the second dichroic mirror 2. The red light R reflected by the first dichroic mirror 1 is sent to the first total reflection mirror 5, and after being reflected there, the red condenser lens 10R, the incident side polarizing plate 8R, the liquid crystal cell. 7R and the exit-side polarizing plate 9R are sent to the third dichroic mirror 3. On the other hand, the second dichroic mirror 2 transmits only the green light G, and among the green light G and blue light B transmitted through the first dichroic mirror 1, green light transmitted through the second dichroic mirror. G is sent to the second total reflection mirror 6 through the green condensing lens 10G, the incident side polarizing plate 8G, the liquid crystal cell 7G, and the output side polarizing plate 9G. Further, the blue light B reflected by the second dichroic mirror 2 passes through the blue condensing lens 10B, the incident side polarizing plate 8B, the liquid crystal cell 7B, and the outgoing side polarizing plate 9B, and passes through the third dichroic mirror 3. Sent to. The third dichroic mirror 3 transmits only the red light R. From the first total reflection mirror 5, the red condenser lens 10R, the incident side polarizing plate 8R, the liquid crystal cell 7R, and the outgoing side polarizing plate 9R. The red light R passing therethrough passes through the third dichroic mirror 3 as it is, and from the second dichroic mirror 2, the blue condenser lens 10B, the incident side polarizing plate 8B, the liquid crystal cell 7B, and the outgoing side polarizing plate 9B. The blue light B that has passed through is reflected by the third dichroic mirror 3 and sent to the fourth dichroic mirror 4. The fourth dichroic mirror 4 transmits only the red light R and the blue light B, and the red light R and the blue light B from the third dichroic mirror 3 are transmitted as they are, and the second total reflection. The green light G from the mirror 6 is reflected here and sent to the magnifying projection lens 16.

  The magnifying projection system has a magnifying projection lens 16, where an image corresponding to each light is enlarged and a magnified image is projected onto the screen 17. In addition, the incident side polarizing plates 8R, 8G, and 8B and the outgoing side polarizing plates 9R, 9G, and 9B of the liquid crystal cells 7R, 7G, and 7B corresponding to the respective colors are used by being bonded to the liquid crystal cells 7R, 7G, and 7B. In general, however, the liquid crystal cells 7R, 7G, and 7B are spaced apart from each other, and this spacing serves as a cooling air passage. Further, the incident-side polarizing plates 8R, 8G, and 8B are spaced from the condenser lenses 10R, 10G, and 10B. As described above, when the polarizing plates 8R, 8G, 8B, 9R, 9G, and 9B are arranged apart from the liquid crystal cells 7R, 7G, and 7B and the condensing lenses 10R, 10G, and 10B, they are attached to a reinforcing material such as glass. Used in a combined form.

  As described above, in the liquid crystal projector, the light of each primary color is obtained by separating the white light from the light source with a dichroic mirror or the like. And in such a liquid crystal panel for a projector, a polarizing film on which a dichroic dye is adsorbed and oriented is frequently used in terms of heat resistance and light resistance to a light source. It is used as a polarizing plate in a state where protective plates are bonded to both sides.

  However, the conventional polarizing plate has a problem that optical characteristics are often deteriorated or discolored due to strong light and heat from the light source. Therefore, the present inventor has developed a polarizing plate with little deterioration against strong light from a light source, and as a result of earnest research to make a liquid crystal projector with excellent durability, a dichroic dye was added to a polyvinyl alcohol film. In the present invention, in the dye-based polarizing film obtained by adsorbing and orienting the dichroic dye, the thickness of the dichroic dye in the cross section of the polyvinyl alcohol film is set to a certain value or more, and the resistance to strong light is increased. It came.

  That is, the present invention has a light source system, a reflection / spectral system, and an enlarged projection system, and the reflection / spectral system corresponds to each of red light, green light, and blue light, and a liquid crystal cell, a light incident side polarizing plate. And at least one of the light incident side polarizing plate and the light emitting side polarizing plate through which blue light passes is adsorbed and oriented on a polyvinyl alcohol film. And a liquid crystal projector comprising a dye-based polarizing plate in which a protective plate is bonded to at least one surface of a polarizing film having a dichroic dye adsorption thickness of 6 μm or more in the cross section of the polyvinyl alcohol film. Is. The dye-based polarizing plate can be bonded to glass and disposed at a distance from the liquid crystal cell.

  Since the polarizing film prescribed | regulated by this invention has durability with respect to the strong light from a light source, and the heat accompanying it, when it is applied to a liquid crystal projector, degradation by light can be suppressed. Therefore, the liquid crystal projector using the polarizing plate in which the protective plate is bonded to the polarizing film is excellent in durability.

BEST MODE FOR CARRYING OUT THE INVENTION

  The polarizing film used in the present invention is a so-called dye-based polarizing film obtained by adsorbing and orienting a dichroic dye on a polyvinyl alcohol film. And what adsorb | sucking thickness of the dichroic dye in the cross section of this polyvinyl alcohol-type film is 6 micrometers or more is employ | adopted. The adsorption thickness of the dichroic dye here refers to the thickness of the layer on which the dichroic dye is adsorbed in the dyed polyvinyl alcohol film, and can be determined by cross-sectional observation.

  The polyvinyl alcohol film is a polymer film mainly composed of vinyl alcohol units or modified products thereof, and specifically, a polymer obtained by saponifying polyvinyl acetate which is a polymer of vinyl acetate. And saponification treatment of vinyl acetate and other monomers copolymerizable therewith, such as unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, etc. Examples thereof include polymer films, and films of polyvinyl formal and polyvinyl acetal, which are modified products of these polymers. The saponification degree of such a polyvinyl alcohol resin is usually 80 to 100 mol%, preferably 98 mol% or more. The degree of polymerization of the polyvinyl alcohol resin in this film is usually 1,000 or more, preferably about 1,500 or more, and more preferably about 2,000 or more. The degree of polymerization is usually about 10,000 or less, preferably about 5,000 or less. The thickness of the polyvinyl alcohol film is, for example, about 50 to 150 μm.

  Examples of the dichroic dye that is adsorbed and oriented on the polyvinyl alcohol film include compounds classified into the following A to E.

A. When expressed in the form of the free acid, the following formula (I)

(Wherein M represents a transition metal selected from copper, nickel, zinc and iron;
A ¹ represents optionally substituted phenyl or optionally substituted naphthyl;
B ¹ represents an optionally substituted 1- or 2-naphthol residue, and the hydroxyl group of the naphthol is adjacent to the azo group and is complex-bonded with the transition metal represented by M;
R ¹ and R ² each independently represent hydrogen, lower alkyl, lower alkoxy, carboxyl, sulfo, sulfamoyl, N-alkylsulfamoyl, amino, acylamino, nitro or halogen)
A metal-containing disazo compound represented by:

B. When expressed in the form of the free acid, the following formula (II)

(In the formula, A ² and B ² each independently represent an optionally substituted phenyl or an optionally substituted naphthyl;
R ³ and R ⁴ each independently represent hydrogen, lower alkyl, lower alkoxy, carboxyl, sulfo, sulfamoyl, N-alkylsulfamoyl, amino, acylamino, nitro or halogen;
m represents 0 or 1)
A trisazo compound represented by:

C. When expressed in the form of the free acid, the following formula (III)

A ³ −N = N−Q ¹ −XQ ² −N = N−B ³ (III)

Wherein A ³ and B ³ each independently represents an optionally substituted phenyl or an optionally substituted naphthyl;
Q ¹ and Q ² each independently represents an optionally substituted phenylene;
X represents a direct bond, -N = N- or -N (→ O) = N-)
A biphenyl disazo, trisazo or disazo monoazoxy compound represented by the formula:

D. When expressed in the form of the free acid, the following formula (IV)

(Wherein M represents a transition metal selected from copper, nickel, zinc and iron;
A ⁴ and B ⁴ each independently represents an optionally substituted 1- or 2-naphthol residue, and the hydroxyl group of the naphthol is adjacent to the azo group and is complexed with the transition metal represented by M. Combined;
Y represents a direct bond, —N═N— or —N (→ O) ═N—;
R ⁵ and R ⁶ each independently represents hydrogen, lower alkyl, lower alkoxy or sulfo)
Metal-containing biphenyl disazo, trisazo or disazo monoazoxy compounds represented by

E. The following dichroic dyes described in the color index (C.I.).
CI Direct Yellow 12,
CI Direct Yellow 28,
CI Direct Yellow 44,
CI Direct Yellow 142,
CI Direct Blue 1,
CI Direct Blue 71,
CI Direct Blue 78,
CI Direct Blue 168,
CI Direct Blue 202,
CI Direct Red 2,
CI Direct Red 31,
CI Direct Red 79,
CI Direct Red 81,
CI Direct Red 247,
CI Direct Violet 9,
CI Direct Violet 51,
CI Direct Orange 26,
CI Direct Orange 39,
CI Direct Orange 107,
CI Direct Green 85,
CI Direct Brown 106,
CI Direct Brown 223 etc.

  In formula (I) and formula (IV), the transition metal represented by M is particularly preferably copper. In addition, the lower alkyl and lower alkoxy defined by the above formulas and the alkyl in N-alkylsulfamoyl each have about 1 to 4 carbon atoms, and the same applies to the lower alkyl and lower alkoxy appearing below. is there. Further, acyl in acylamino may be about 2 to 4 carbon atoms in total such as acetyl and propionyl, and specific examples of halogen include fluorine, chlorine, bromine and the like.

A ¹ in formula (I), A ² and B ² in formula (II), and A ³ and B ^{3 in} formula (III) are each phenyl or naphthyl, and these phenyl and naphthyl are respectively It may be unsubstituted or substituted. Examples of the group that can be substituted with phenyl include sulfo, sulfamoyl, lower alkyl, lower alkoxy, nitro, hydroxyl group, carboxyl, unsubstituted or mono- or di-substituted amino, halogen, and the like. Examples of the group that can be substituted are lower alkyl, lower alkyl substituted with a hydroxyl group or cyano, acyl having 2 to 4 carbon atoms, and the like. Examples of the group that can be substituted with naphthyl include sulfo, a hydroxyl group, and amino.

B ¹ in the formula (I) and A ⁴ and B ⁴ in the formula (IV) are each 1- or 2- which is in a complex bond with the transition metal represented by M, with the hydroxyl group adjacent to the azo group It is a residue of naphthol, and this naphthol residue may be unsubstituted or substituted. Examples of the group that can be substituted with the naphthol residue include sulfo, hydroxyl group, carboxyl, unsubstituted or mono- or di-substituted amino, and the group that can be substituted with amino includes, for example, lower Examples thereof include lower alkyl substituted with alkyl, hydroxyl group or cyano, acyl having 2 to 4 carbon atoms, carbamoyl, sulfamoyl, unsubstituted or substituted phenyl, unsubstituted or substituted benzoyl, and the like. Examples of the group that can be substituted with phenyl and benzoyl here include sulfo, lower alkyl, and lower alkoxy.

Q ¹ and Q ^{2 in} formula (III) are each phenylene, which may be unsubstituted or substituted, and Q ¹ and Q ² may be the same or different. Examples of the group that can be substituted with phenylene include a hydroxyl group, lower alkyl, lower alkoxy, sulfo, and the like. Q ¹ and Q ² are each preferably unsubstituted or phenylene having one or two substituents, which is also p-phenylene. X in the formula (III) and Y in the formula (IV) are each a direct bond, azo (—N═N—) or azoxy (—N (→ O) ═N—).

R ¹ and R ^{2 in} formula (I), and R ³ and R ^{4 in} formula (II) are each hydrogen, lower alkyl, lower alkoxy, carboxyl, sulfo, sulfamoyl, N-alkylsulfamoyl, amino, Acylamino, nitro or halogen. R ⁵ and R ⁶ in formula (IV) are each hydrogen, lower alkyl, lower alkoxy or sulfo.

  The compounds represented by formula (I), formula (III) and formula (IV) usually have at least one sulfo or carboxyl in the molecule as a water-soluble group. As the water-soluble group, sulfo is particularly preferable, and it is more preferable to have two or more sulfos in the molecule. Similarly, the compound represented by the formula (II) preferably has two or more sulfos in the molecule.

  Of the above dichroic dyes, the compounds having sulfo or carboxyl when expressed in the form of free acid are usually used in the form of alkali metal salts, especially sodium salts. It can be used in the form of other alkali metal salts such as potassium salt or in the form of free acid. Furthermore, it can also be used in the form of an ammonium salt, or an amine salt such as an ethanolamine salt or an alkylamine salt.

Any of these dichroic dyes can be produced according to a known method. That is, the metal-containing disazo compound represented by the formula (I) can be produced according to a known method described in, for example, West German Patent No. 32 36 238 or Japanese Patent Publication No. 64-5623, The trisazo compound represented by the formula (II) can be produced, for example, according to a known method described in JP-A-2-75672, and among the compounds represented by the formula (III), Disazomonoazoxy compounds and metal-containing trisazo or disazomonoazoxy compounds among the compounds represented by formula (IV) are, for example, Ind. Eng. Chem., 27 , 1045 (1935) and J. Am. Chem. Soc. ., 73 , 1323 (1951) and the like.

  In adsorbing and orienting the above dichroic dye on the polyvinyl alcohol film, any one dichroic dye may be used, or two or more dichroic dyes may be used in combination.

  In order to adsorb and orient such a dichroic dye on the polyvinyl alcohol film, for example, a method of stretching the polyvinyl alcohol film and immersing it in an aqueous solution of the dichroic dye can be employed. The aqueous solution used for dyeing is usually prepared by dissolving a dichroic dye at a ratio of about 0.0001 to 1 part by weight with respect to 100 parts by weight of water. A dyeing assistant may be added to this aqueous solution. For example, when using nitric acid as a dyeing assistant, the amount used is about 0.1 to 10 parts by weight per 100 parts by weight of water. The higher the temperature of this aqueous solution, the better. For example, it is preferably about 68 to 80 ° C, more preferably about 70 to 80 ° C. If the dyeing temperature is too high, the film dissolves, so there is an upper limit temperature at which continuous processing is possible. Further, in the immersion treatment (dyeing), it is preferable that the tension applied to the film is low. However, since the film is dissolved if the tension is too low, it is preferable to dye while applying a certain amount of tension. Accordingly, the tension at this time is suitably 160 g / cm or less, for example.

  Moreover, it is preferable that the polyvinyl alcohol film is subjected to an immersion treatment in warm water before the dyeing treatment. When such a hot water treatment is employed, a treatment temperature of about 40 to 65 ° C. and a treatment time of about 10 to 300 seconds are appropriate.

  The stretching of the polyvinyl alcohol film may be performed before the immersion treatment in the aqueous solution of the dichroic dye, may be performed while the immersion treatment is performed, or may be performed after the immersion treatment. Stretching is usually performed by uniaxial stretching. The method for uniaxial stretching is not particularly limited, and may be either wet stretching or dry stretching. The draw ratio is usually 4 times or more, preferably 8 times or less. In order to uniaxially stretch a polyvinyl alcohol-based film in a dry manner, for example, a method in which the film is brought into contact with a heating roll to be oriented in the longitudinal direction while applying a back tension to the film, and between a pair of heating rolls. A method of passing and compressing and stretching is used. The temperature of the heating roll is not lower than the glass transition temperature of the polyvinyl alcohol-based resin, and is usually 160 ° C. or lower, preferably about 80 to 130 ° C.

  The polyvinyl alcohol film in which the dichroic dye is adsorbed and oriented in this manner is usually subjected to boric acid treatment thereafter. The boric acid treatment is performed by immersing this film in an aqueous solution containing boric acid. The concentration of boric acid in this aqueous solution is not particularly limited. Usually, however, an aqueous solution in which boric acid is dissolved at a ratio of about 2 to 15 parts by weight, preferably about 5 to 12 parts by weight, with respect to 100 parts by weight of water. Used. The temperature of the boric acid-containing aqueous solution is usually about 60 to 85 ° C, preferably about 65 to 80 ° C. The treatment time is not particularly limited, but is usually about 100 to 1,200 seconds, preferably about 150 to 600 seconds. After the boric acid treatment, the polarizing film having the dichroic dye adsorbed and oriented can be obtained by washing and drying in the same manner as usual.

  In the present invention, the polarizing film is a polyvinyl alcohol film produced as described above and having a dichroic dye adsorbed and oriented and having a dichroic dye adsorption thickness of 6 μm or more. In order to increase the adsorption thickness of the dichroic dye in this way, as described above, for example, the temperature at the time of dyeing with an aqueous solution containing the dichroic dye is set higher, or during the dyeing process What is necessary is just to set the tension | tensile_strength provided to a film low.

  This polarizing film usually has a protective plate bonded on one side or both sides thereof to form a polarizing plate. The protective plate is the same as that used for ordinary polarizing films, for example, cellulose acetate film, acrylic film, polyester film, cyclic polyolefin film having a norbornene structure, polyolefin film, polycarbonate film, etc. Polyarylate films, polyethersulfone films, and the like can be used. Examples of the cellulose acetate film include a triacetyl cellulose film and a diacetyl cellulose film. The thickness of the protective plate is not particularly limited, but is usually about 40 to 200 μm. These protective plates may contain an ultraviolet absorber or the like, and commercially available products can be used as such protective plates. Examples of commercially available protective plates include “Konica KC80UVSF” and “Konica KC80UVN” (both manufactured by Konica Corporation), which are triacetyl cellulose films.

  Various optical functional treatments may be performed on the surface of the polarizing plate, and for example, antireflection treatment can be performed. The antireflection treatment is not particularly limited, and examples thereof include a method of forming an antireflection layer by laminating two or more layers made of a substance selected from inorganic and organic substances such as metals and metal oxides on the surface. It is done. Examples of the metal used in this case include silver. Examples of the metal oxide include titanium oxide, silicon oxide, indium oxide, aluminum oxide, cesium oxide, tin oxide, zirconium oxide, yttrium oxide, and tantalum oxide. Examples of inorganic substances other than these metals and metal oxides include magnesium fluoride. Examples of the organic substance include a fluorine-based resin. Examples of the method for laminating these substances include vapor deposition, sputtering, ion plating, etc., and coating methods such as roll coating, gravure coating, and spray coating. In order to improve the adhesion between the antireflection layer and the protective plate, the surface of the protective plate is preferably subjected to hard coat treatment, corona treatment, chemical cleaning, and the like. Such an antireflection treatment may be performed on one side of the polarizing plate or may be performed on both sides.

  The polarizing plate having the protective plate bonded to the dye-based polarizing film as described above is applied to one or a plurality of liquid crystal cells corresponding to the three primary colors constituting the liquid crystal projector, and is provided on at least one surface side thereof. Can be arranged. Among these, among the three liquid crystal panels constituting the liquid crystal projector, the light incident side adjacent to the polarizing plate of the liquid crystal panel through which blue light with particularly high light energy passes, that is, the blue light liquid crystal cell 7B shown in FIG. Although it is effective to use it for the polarizing plate 8B and the light emission side polarizing plate 9B, it can of course be used for a liquid crystal panel corresponding to green light or red light.

  In order to dispose the polarizing plate on both sides or one side of the liquid crystal cell, the polarizing plate may be bonded to the liquid crystal cell using a transparent adhesive. In this case, the polarizing plate is bonded via another optical element. Also good. Moreover, in order to avoid the influence of the heat generated from the polarizing film, it is preferable to arrange the liquid crystal cell with a space. Thus, when arrange | positioning at intervals from a liquid crystal cell, it arrange | positions in the form like the light-incidence side polarizing plate 8R, 8G, 8B and the light emission side polarizing plate 9R, 9G, 9B shown in FIG. Thus, for example, an appropriate mode is selected such that the polarizing film or the polarizing plate is bonded to the surface of the glass which has been subjected to non-reflective treatment on one side, and which has not been subjected to non-reflective treatment.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited at all by these Examples. The transmittance T (λ) at an arbitrary wavelength λ is measured using a spectrophotometer [“UV-2200” manufactured by Shimadzu Corporation], and the polarization degree P (λ) of the polarizing film at an arbitrary wavelength λ. Was obtained from the parallel transmittance Tp (λ) and the orthogonal transmittance Tc (λ) by the following equation (1).

  In the following example, the surface temperature is kept at 120 ° C. while lightly cooling the polarizing plate, and irradiated with high-pressure mercury lamp light for a liquid crystal projector for 48 hours, and irradiation defined by the following formula (2) The difference ΔP (λ) between the degree of polarization before and after irradiation was used as an index of light resistance. The smaller ΔP (λ), the better the light resistance.

ΔP (λ) = [P (λ) before light irradiation] − [P (λ) after light irradiation] (2)

Example 1
A film of polyvinyl alcohol having a polymerization degree of 2,400 and having a thickness of 75 μm is uniaxially about 5 times by a method in which the film is brought into contact with a heating roll at about 120 ° C. and oriented longitudinally uniaxially while applying a back tension to the film. Stretched. The stretched film is immersed in warm water at 60 ° C. for 60 seconds, and then 0.025 part by weight of CI Direct Orange 39 and 0.015 part by weight of CI Direct Red 81 per 100 parts by weight of water. The sample was immersed in a 70 ° C. aqueous solution in which 2 parts by weight and 2 parts by weight of sodium nitrate were dissolved for dyeing for 120 seconds. Next, the dyed film was immersed in a 76 ° C. aqueous solution consisting of 100 parts by weight of water and 7.5 parts by weight of boric acid for 300 seconds. Then, it washed with water and dried and obtained the polarizing film. When the cross section was observed, the adsorption thickness of the dye was about 6 μm. A triacetyl cellulose film [“Konica KC80UVN” manufactured by Konica Co., Ltd.] was bonded to both surfaces of this polarizing film to obtain a polarizing plate.

  When the obtained polarizing plate was irradiated with light from a high-pressure mercury lamp, the polarization degree difference ΔP at a wavelength of 440 nm before and after the light irradiation was 1.3%.

Comparative Example 1
A polarizing film was produced in the same manner as in Example 1 except that the temperature of the aqueous dye solution was 65 ° C. The obtained polarizing film had a dye adsorption thickness of 3 μm. The same triacetyl cellulose film as used in Example 1 was bonded to both surfaces of this polarizing film to obtain a polarizing plate.

  When the obtained polarizing plate was irradiated with light from a high-pressure mercury lamp, the polarization degree difference ΔP at a wavelength of 440 nm before and after the light irradiation was 5.1%.

It is a figure which shows the structure of a liquid crystal projector roughly.

Explanation of symbols

1,2,3,4 ... Dichroic mirror,
5, 6 ... Total reflection mirror,
7R, 7G, 7B ... Liquid crystal cell,
8R, 8G, 8B ... Incident side polarizing plate,
9R, 9G, 9B ... Output side polarizing plate,
10R, 10G, 10B ... Condensing lens,
L: White light (light source light),
R …… Red light,
G ... Green light,
B …… Blue light,
11 …… Light source,
13 …… Condensing lens,
14 …… UV / IR cut filter,
16 ... Magnifying projection lens,
17: Screen.

Claims (2)

  It has a light source system, a reflection / spectral system, and an enlarged projection system, and the reflection / spectral system corresponds to each of red light, green light, and blue light, a liquid crystal cell, a light incident side polarizing plate, and a light emitting side polarized light. A liquid crystal projector including a plate, wherein at least one of a light incident side polarizing plate and a light emitting side polarizing plate through which blue light passes is formed by adsorbing and orienting a dichroic dye on a polyvinyl alcohol-based film. A liquid crystal projector comprising a dye polarizing plate in which a protective plate is bonded to at least one surface of a polarizing film having an adsorption thickness of 6 μm or more in the cross section of an alcohol film. The liquid crystal projector according to claim 1, wherein the dye-based polarizing plate is bonded to glass and disposed at a distance from the liquid crystal cell.

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