JP2012220810A - Liquid crystal device and projector - Google Patents

Abstract

Provided is a liquid crystal device capable of further improving light resistance and extending a lifetime by suppressing deterioration of a liquid crystal layer while preventing reflection of dust and the like.
In a liquid crystal device 1 in which a liquid crystal layer 30 is sandwiched between an element substrate 10 and a counter substrate 20, a dustproof substrate bonded to a surface of the counter substrate 20 opposite to the side facing the liquid crystal layer 30. 50 and the dustproof substrate 50 has a function of cutting light on the short wavelength side. Thereby, deterioration of the liquid crystal layer 30 can be suppressed while preventing reflection of dust or the like.
[Selection] Figure 2

Description

  The present invention relates to a liquid crystal device and a projector including such a liquid crystal device.

In recent years, in a liquid crystal device used for a projector, with the increase in luminance, deterioration of an alignment film due to light has become a problem. For this reason, compared with organic materials, such as a polyimide, the inorganic alignment film excellent in light resistance and heat resistance has come to be employ | adopted.

As the inorganic alignment film, those using an oblique deposition method, a directional sputtering method, a coating type inorganic material having a siloxane skeleton, and the like have been proposed. Among them, the oblique vapor deposition method is generally used for a liquid crystal display device for a projector.

In such a liquid crystal device for projector use, a vertical alignment mode is used as a liquid crystal mode. In this vertical alignment mode liquid crystal device, a predetermined pretilt angle is given to liquid crystal molecules when no electric field is applied, and birefringence is obtained by tilting and aligning liquid crystal molecules when a voltage is applied.

By the way, with respect to the deterioration of the alignment film described above, although the light resistance has been drastically improved by using the inorganic alignment film, the deterioration due to the light of the liquid crystal material itself in the liquid crystal panel has become a problem. . In particular, many liquid crystal materials have light absorptivity in the ultraviolet region. If light having a wavelength in the ultraviolet region is included in the light emitted from the light source, it is used for a long time even if it is weak. As a result, the liquid crystal material is deteriorated and the display quality is lowered.

On the other hand, in a liquid crystal device for a projector, when dust or the like adheres to the substrate surface, the light from the light source is condensed near the substrate surface, so that these shadows are magnified and projected onto the screen as display defects. There is a problem of being reflected.

For such a problem, by attaching a dust-proof substrate to the outer surface of the substrate (opposite the surface facing the liquid crystal layer), the surface to which dust or the like adheres and the light emitted from the light source Measures are taken so as not to affect the display quality while separating the focused surface and defocusing dust and the like (see, for example, Patent Documents 1 and 2).

JP 2004-117580 A JP 2005-195909 A

However, using such a dustproof substrate can suppress the reflection of dust and the like on the screen, but it is difficult to suppress the deterioration of the liquid crystal due to the light in the ultraviolet region described above.

For example, Patent Document 1 below describes that a quartz having a high thermal conductivity is used as a dust-proof substrate, and that this dust-proof substrate has a function as a heat sink. However, since quartz shows high transmittance (about 90%) for light having a wavelength in the ultraviolet region, it is difficult to suppress the deterioration of the liquid crystal due to the light in the ultraviolet region described above.

On the other hand, the following Patent Document 2 describes that a composite glass obtained by bonding quartz or crystallized glass and high thermal conductivity glass is used as a dustproof substrate, and thereby a high heat dissipation effect is obtained. . However, the dustproof substrate described in Patent Document 2 is intended to obtain a heat dissipation effect, and like the dustproof substrate described in Patent Document 1, the above-described deterioration of liquid crystal due to light in the ultraviolet region is suppressed. It is difficult.

The present invention has been proposed in view of such circumstances, and by further preventing deterioration of the liquid crystal layer while preventing the reflection of dust and the like, it is possible to further improve the light resistance and extend the lifetime. An object of the present invention is to provide a liquid crystal device. It is another object of the present invention to provide a projector having both good display characteristics and high reliability by including such a liquid crystal device.

In order to achieve the above object, a liquid crystal device according to the present invention is disposed to face each other with a liquid crystal layer interposed between a light source, a first substrate on which light emitted from the light source is incident, and the first substrate. In the liquid crystal device including the second substrate and the third substrate disposed on the light incident side of the light source of the first substrate, the third substrate has a shorter wavelength band of the incident light. The light having a wavelength band longer than the predetermined wavelength, which is a wavelength, is transmitted to the liquid crystal layer side, and the light having a wavelength band shorter than the predetermined wavelength, which is a short wavelength, is not transmitted to the liquid crystal layer side. And

According to this configuration, the surface of the third substrate to which dust or the like adheres is separated from the surface on which the light emitted from the light source is collected so that the display quality is not affected while the dust or the like is defocused. In addition to the function, the third substrate has a function of cutting light on the short wavelength side, so that deterioration of the liquid crystal layer can be suppressed while preventing reflection of dust and the like.
Therefore, according to the present invention, it is possible to provide a liquid crystal device that is optimal for projector use as a liquid crystal device capable of further improving light resistance and extending its life.

In the liquid crystal device, the third substrate is preferably made of crystallized glass having a thickness set so as not to transmit light having a short wavelength and a wavelength band equal to or shorter than a predetermined wavelength to the liquid crystal layer side.
In this case, it is possible to achieve both a function of preventing reflection of dust and the like and a function of cutting light on the short wavelength side. Further, it is possible to provide a function of cutting light on the short wavelength side even for light incident from an oblique direction.

In the liquid crystal device, the third substrate preferably has a structure in which an optical multilayer film is stacked on the surface of the transparent substrate.
In this case, it is possible to achieve both a function of preventing reflection of dust and the like and a function of cutting light on the short wavelength side. Further, it is possible to arbitrarily adjust the wavelength range of light to be cut by adjusting the optical multilayer film.

In the liquid crystal device, the third substrate preferably has a structure in which crystallized glass and a transparent substrate on which an optical multilayer film is stacked are bonded.
In this case, it is possible to achieve both the function of preventing the reflection of dust and the like and the function of cutting light in the short wavelength region. Even if light on the short wavelength side leaks from the optical multilayer film with respect to light incident from an oblique direction, the crystallized glass can cut the light on the short wavelength side. Furthermore, it is possible to reduce the thickness by combining the crystallized glass and the transparent substrate on which the optical multilayer film is laminated on the surface, as compared with the case of cutting light on the short wavelength side only by the crystallized glass. .

Further, in the liquid crystal device, the wavelength band of a predetermined wavelength or less that is a short wavelength of the third substrate is
A wavelength band of 350 nm or less is preferable.
In this case, the deterioration of the liquid crystal layer can be suppressed, and the light resistance can be improved and the life can be extended.

Further, in the liquid crystal device, the wavelength band of a predetermined wavelength or less that is a short wavelength of the third substrate is
A wavelength band of 430 nm or less is preferable.
In this case, the deterioration of the liquid crystal layer can be further suppressed, and the light resistance can be improved and the life can be extended.

Further, in the liquid crystal device, on the surface of the first substrate and the second substrate facing the liquid crystal layer,
It is preferable to provide an inorganic alignment film that controls the alignment direction of each liquid crystal layer.
In this case, it is possible to provide an optimum liquid crystal device for projector use as a liquid crystal device excellent in heat resistance and light resistance.

In the projector according to the invention, the liquid crystal device is provided as a light valve that forms image light obtained by modulating light according to image information, and has a projection optical system that projects image light.
According to this configuration, it is possible to provide a projector having both good display characteristics and high reliability.

It is a figure which shows typically the cross-section of the liquid crystal device which concerns on embodiment of this invention. It is an example of the liquid crystal device to which the dustproof board | substrate was attached, Comprising: (a) is the top view, (b) is the A-A 'sectional drawing. It is an example which shows the dust-proof board | substrate of this invention, (a) is the case where crystallized glass is used, (b) is the case where the transparent substrate on which the optical multilayer film was laminated | stacked on the surface, (c) is crystallized. It is sectional drawing at the time of combining glass and the transparent substrate by which the optical multilayer film was laminated | stacked on the surface. It is a schematic diagram which shows the structure of a projector. 3 is a graph showing the result of measuring the spectrum of Example 1. It is a graph which shows the result of having measured the spectrum of Example 2. FIG. 6 is a graph showing the result of measuring the spectrum of Comparative Example 1. It is a graph which shows the result of having measured the spectrum of comparative example 2. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each of the following drawings, the scale of each layer and each member is different in order to make each layer and each member recognizable on the drawing.

(Liquid crystal device)

FIG. 1 is a diagram schematically showing a cross-sectional structure of a liquid crystal device 1 according to an embodiment of the present invention.
The liquid crystal device 1 includes a liquid crystal layer 30 made of a liquid crystal material having a negative dielectric anisotropy between an element substrate 10 that is a first substrate and a counter substrate 20 that is a second substrate disposed opposite thereto. Are sandwiched, and the initial alignment state is vertical alignment. The liquid crystal device 1 is an active matrix reflective liquid crystal device using a TFT (Thin-Film Transistor) element as a switching element.

The element substrate 10 includes a base material part 14 and a first alignment film 15 provided on one surface side of the base material part 14. The first alignment film 15 is for imparting a pretilt angle in a predetermined direction to the liquid crystal molecules 30a.

The base material part 14 is mainly composed of a substrate body 11 made of a translucent material such as glass, and a pixel made of a highly reflective conductive material such as Al or Ag is formed on the inner surface of the substrate body 11. An electrode 12 is formed. A passivation film 13 made of silicon oxide (SiO _x ) as silicon oxide is formed on the pixel electrode 12 by, for example, vacuum evaporation or sputtering (DC
The film is formed by a PVD method such as sputtering) or a CVD method. As a material for forming the passivation film 13, silicon nitride (SiN _x ) as silicon nitride,
Alternatively, aluminum oxide (Al _x O _y ) as an aluminum oxide can be used (x and y are positive integers).

In addition, the element substrate 10 includes a TFT element that is a switching element for controlling energization to the pixel electrode 12, a data line to which an image signal is supplied, a scanning line (none of which is shown), and the like. Note that the data line and the scanning line may have a function as a light shielding film.

On the other hand, the counter substrate 20 includes a base material portion 24 and a second alignment film 25 provided on one surface side of the base material portion 24. The second alignment film 25 is for imparting a pretilt angle in a predetermined direction to the liquid crystal molecules 30a.

The base material part 24 is mainly composed of a substrate body 21 made of a translucent material such as glass, and a counter electrode 22 made of a transparent conductive material such as ITO is formed on the inner surface of the substrate body 21. . The counter electrode 22 is formed in a solid shape on the entire surface of the substrate body 21. Counter electrode 22
On the top, a passivation film 23 is formed by, for example, a CVD method. The material for forming the passivation film 23 is made of the same material as that for the passivation film 13. A polarizing plate 42 is formed on the outer surface of the substrate body 21. The counter substrate 2
0 includes a color filter and a light shielding film.

Between the element substrate 10 and the counter substrate 20, a liquid crystal layer 30 having an initial alignment state of vertical alignment is sandwiched between the first alignment film 15 and the second alignment film 25. In the liquid crystal layer 30, the initial alignment state (alignment state when no voltage is applied) of the liquid crystal molecules 30a exhibits vertical alignment.

The first alignment film 15 and the second alignment film 25 are both made of an inorganic alignment film, and can be obtained by evaporating an inorganic material on the substrate bodies 11 and 21 using, for example, an oblique evaporation method. The first alignment film 15 and the second alignment film 25 have a plurality of columnar laminates, and have a porous surface with unevenness. The plurality of columnar laminates have a surface shape corresponding to the angle of incidence during oblique deposition, and the surface shape causes the pretilt angle (
The angle with respect to the normal direction of the substrate bodies 11 and 21 is given, and the tilt direction when driving the liquid crystal molecules 30a is defined.

As a material of the first alignment film 15 and the second alignment film 25, silicon oxide (SiO _x ) can be used. Here, silicon oxide is an inorganic material including one or more materials of SiO ₂ and SiO. In addition to silicon oxide, inorganic materials such as SiON and SiN can also be used.

In the liquid crystal device 1, as shown in FIGS. 2A and 2B, the peripheral portion between the element substrate 10 and the counter substrate 20 arranged to face each other has a substantially rectangular frame shape in plan view. Seal material 31
And the element substrate 10 and the counter substrate 20 are bonded to each other through the sealing material 31. The liquid crystal layer 30 is formed inside the sealing material 31 with a thickness corresponding to the cell gap.

The liquid crystal device 1 includes a dust-proof substrate 50 that is a third substrate bonded to the surface of the counter substrate 20 opposite to the side facing the liquid crystal layer 30. The dustproof substrate 50 has a function of separating the surface on which dust or the like adheres from the surface on which the light emitted from the light source is collected so as not to affect the display quality while defocusing the dust or the like. .

The dustproof substrate 50 has a function of cutting light on the short wavelength side, that is, the liquid crystal layer 30 transmits light in a wavelength band longer than a predetermined wavelength, which is a short wavelength, in the wavelength band of incident light. And has a function of not transmitting light in a wavelength band equal to or shorter than a predetermined wavelength, which is a short wavelength, to the liquid crystal layer 30 side.

Here, the light on the short wavelength side means light in a wavelength region that causes deterioration of the liquid crystal layer 30 by absorption by the liquid crystal layer 30, and the liquid crystal material has light absorption in the ultraviolet region. Since there are many, it refers to light having such a wavelength in the ultraviolet region, specifically light having a wavelength of 350 nm or less, and further light having a wavelength of 430 nm or less. In the present invention, not only light having a wavelength of 350 nm or less or 430 nm or less is cut, but in addition to cutting light having these wavelengths, a part of light on the longer wavelength side than the wavelength is also cut. Including the case of cutting, it is possible to suppress the deterioration of the liquid crystal layer 30.

For example, a crystallized glass 51 as shown in FIG. 3A is used as the dustproof substrate 50 that achieves both the function of preventing the reflection of dust and the like and the function of cutting light on the short wavelength side. Can do. The crystallized glass 51 is made of, for example, neo-serum (manufactured by Nippon Electric Glass Co., Ltd.) or clear serum (manufactured by OHARA), etc. It is pasted on the surface.

The crystallized glass 51 is formed with a thickness sufficient to cut the light on the short wavelength side described above. On the other hand, if the thickness of the crystallized glass 51 is insufficient, it is difficult to exhibit the function of cutting light on the short wavelength side even if the function of preventing the reflection of dust or the like is obtained. Therefore, although the thickness of the crystallized glass 51 is not particularly defined, it is desirable to set the thickness within a range that does not increase the thickness unnecessarily.

On the other hand, the dustproof substrate 50 may have a structure in which an optical multilayer film 53 is laminated on the surface of a transparent substrate 52 as shown in FIG. 3B, for example. The transparent substrate 52 is made of, for example, quartz glass or the like, is formed in a rectangular flat plate shape, and is bonded to the surface of the counter substrate 20 opposite to the side facing the liquid crystal layer 30. The optical multilayer film 53 is formed by alternately laminating dielectric films 53a and 53b made of different materials such as TiO ₂ and SiO ₂ on the surface of the transparent substrate 52, and a combination of these dielectric films 53a and 53b. It is possible to arbitrarily adjust the wavelength range of light to be cut by adjusting the thickness, the number of layers, the number of layers, and the like. That is, the optical multilayer film 53 is adjusted to cut the light on the short wavelength side described above. The optical multilayer film 53 can be laminated on the surface of the transparent substrate 52 on the side to be bonded to the counter substrate 20.

On the other hand, the dust-proof substrate 50 has, for example, a structure in which the crystallized glass 51 as shown in FIG. 3C and a transparent substrate 52 on which the optical multilayer film 53 is laminated are bonded together. There may be.

In this case, even if light on the short wavelength side leaks from the optical multilayer film 53 with respect to light incident from an oblique direction, the crystallized glass 51 can cut the light on the short wavelength side. Furthermore, compared with the case where light on the short wavelength side is cut only by the crystallized glass 51, the combination of the crystallized glass 51 and the transparent substrate 52 in which the optical multilayer film 53 is laminated on the surface reduces the thickness. Is possible.

The dust-proof substrate 50 shown in FIG. 3 has a structure in which a transparent substrate 52, an optical multilayer film 53, and a dust-proof substrate 51 are laminated in this order on the surface of the counter substrate 20 opposite to the side facing the liquid crystal layer 30. However, the present invention is not limited to such a structure, and the order of the optical multilayer film 53, the transparent substrate 52 and the dust-proof substrate 51, or the order of the dust-proof substrate 51, the optical multilayer film 53 and the transparent substrate 52, or the dust-proof substrate 51. The transparent substrate 52 and the optical multilayer film 53 may be stacked in this order.

As described above, in the liquid crystal device 1, deterioration of the liquid crystal layer 30 can be suppressed while preventing reflection of dust and the like. Therefore, according to the present invention, it is possible to provide the liquid crystal device 1 that is most suitable for projector use as the liquid crystal device 1 that can further improve the light resistance and extend the life.

(projector)
Next, a configuration of the projector 100 including the liquid crystal device 1 according to the embodiment of the present invention as a light valve (light modulation unit) will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating a schematic configuration of the projector 100.

The projector 100 according to the present embodiment includes a polarized illumination device 101 that is schematically configured by a light source unit 110, a lens array 120, a reflection mirror 160, and an optical element 130. Also,
A color separation optical system 500 that separates light from the polarized illumination device 101 into three color light beams, and a plurality of light valves 3 that modulate each of the three color light beams separated by the color separation optical system 500.
00R, 300G, 300B, a cross dichroic prism 550 that synthesizes light modulated by the three light valves 300R, 300G, 300B, and a projection optical system 600 that projects the color light synthesized by the cross dichroic prism 550 onto the projection surface 700.
And. Further, the respective color lights separated by the color separation optical system 500 are reflected to reach the light valves 300R, 300G, and 300B, and the light valve 3
Three polarization beam splitters 200R, 200G, and 200B that transmit light modulated by 00R, 300G, and 300G and reach the cross dichroic prism 550 are provided.

The light source unit 110 is roughly composed of a light source lamp 111 and a parabolic reflector 112. The light emitted from the light source lamp 111 is reflected in one direction by the parabolic reflector 112 and enters the lens array 120 as a substantially parallel light beam. Here, as the light source lamp 111, a metal halide lamp, a xenon lamp, a high-pressure mercury lamp, a halogen lamp, or the like is used, and as the reflector, the parabolic reflector 112 described in the present embodiment is used.
Besides, an elliptical reflector, a spherical reflector, etc. can be used.

The reflection mirror 160 is disposed between the lens array 120 and the optical element 130.
The light transmitted through the lens array 120 is reflected by the reflection mirror 160 and enters the optical element 130.

The optical element 130 includes a condenser lens array 131, a plate-shaped polarization conversion element 140 including a polarization separation unit array 141 and a selective phase difference plate 147, and an intermediate light beam emitted from the polarization conversion element 140 to the reflective liquid crystal element 300. It is a composite that is roughly composed of the exit side lens 150 to be superimposed. The optical element 130 separates each of the intermediate light beams into a P-polarized light beam and an S-polarized light beam, and then aligns the polarization direction of one polarized light beam with the polarization direction of the other polarized light beam, so that the polarization directions are substantially aligned. The light beam is guided to one illuminated area.

In the polarization illumination device 101, a random polarized light beam emitted from the light source unit 110 is divided into a plurality of intermediate light beams by the lens array 120, and then a single type of polarized light beam (mainly aligned by the optical element 130). In the embodiment, it is converted into an S-polarized light beam.

The color separation optical system 500 converts the light emitted from the polarization illumination device 101 into red light R, green light G,
This is an optical system that separates the three colors of blue light B. The color separation optical system 500 includes a blue light / green light reflecting dichroic mirror 501, a red light reflecting dichroic mirror 502, a green light reflecting dichroic mirror 505, and two reflecting mirrors 503 and 504.

The light emitted from the polarization illumination device 101 enters the color separation optical system 500. Of the light emitted from the polarization illumination device 101, the red light R component is reflected by the red light reflecting dichroic mirror 502 toward the reflecting mirror 503. The red light R thus separated enters the polarization beam splitter 200R.

On the other hand, components of green light G and blue light B out of the light emitted from the polarization illumination device 101 are reflected by the green light / blue light reflecting dichroic mirror 501 toward the reflection mirror 504. Further, the green light G and the blue light B reflected by the reflection mirror 504 enter the green light reflection dichroic mirror 505, where only the component of the green light G is reflected. The green light G reflected by the green light reflecting dichroic mirror 505 is incident on the polarization beam splitter 200G. The blue light B transmitted through the green light reflecting dichroic mirror 505 is
The light enters the polarization beam splitter 200B.

Most of the S-polarized light beams incident on the polarization beam splitters 200R, 200G, and 200B are reflected by the S-polarized light beam reflecting films of the polarization beam splitters 200R, 200G, and 200B, so that the reflective liquid crystal elements 300R and 300G are reflected. , 300B will be reached.

Each color light incident on the light valves 300R, 300G, and 300B undergoes modulation based on predetermined image information, and is emitted to the polarization beam splitters 200R, 200G, and 200B side.
Only the light transmitted through each S-polarized light flux reflecting film is emitted to the cross dichroic prism 550 side.

The cross dichroic prism 550 is composed of four triangular prisms each having an isosceles triangle cross section in the XZ plane. The side surfaces of the four triangular prisms are bonded to each other, and two types of dichroic films 551 and 552 are formed along the bonding surfaces.
Is formed. The wavelength selection characteristic of the dichroic film 551 is set so as to reflect the red light R and transmit the green light G and the blue light B. The wavelength selection characteristics of the dichroic film 552 are set so as to reflect the blue light B and transmit the red light R and the green light G. Accordingly, the light incident on the cross dichroic prism 550 is synthesized based on the wavelength selection characteristics of the two types of dichroic films 551 and 552 and projected onto the projection surface 700 via the projection optical system 600.

As described above, according to the present invention, as the light valves 300R, 300G, and 300B,
Since the liquid crystal device 1 that can further improve the light resistance and extend the life described above is provided, it is possible to provide the projector 100 having both good display characteristics and high reliability.

The preferred embodiment of the present invention has been described above with reference to the accompanying drawings.
It goes without saying that the present invention is not limited to such examples.

Specifically, in the above-described embodiment, the reflective liquid crystal device 1 is exemplified, but the present invention can also be applied to a transmissive liquid crystal device and a projector using such a transmissive liquid crystal device as a light valve. It is. In this case, in general, in the transmissive type, the dustproof substrate 50 is disposed outside the light incident side substrate (light incident side) or outside both the incident side and emission side substrates. On the other hand, in the reflection type described above, light is incident and exited on the same side, and is disposed outside one substrate on which light is incident and exited.

Further, the shapes and combinations of the constituent members shown in the above-described examples are examples,
Various modifications can be made based on design requirements and the like without departing from the spirit of the present invention. For example, as the pixel electrode 9 and the common electrode 21, IZO (indium zinc oxide) may be used instead of ITO.

Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement.

Example 1
In Example 1, using a crystallized glass (neo-ceram) having a thickness of 2.3 mm as a dust-proof substrate and a high-pressure mercury lamp as a light source, a spectrum was measured after light emitted from the light source was transmitted through the dust-proof substrate. The measurement results are shown in FIG.
As shown in FIG. 5, it can be seen that the dustproof substrate of Example 1 has a function of cutting light having a wavelength of 350 nm or less.

(Example 2)
In Example 2, the same procedure as in Example 1 was used, except that the dust-proof substrate used was a laminate of TiO ₂ and SiO ₂ alternately laminated as an optical multilayer film on the surface of a quartz substrate having a plate thickness of 1.0 mm. The spectral spectrum after the light emitted from the light source transmitted through the dust-proof substrate was measured. The measurement results are shown in FIG.
As shown in FIG. 6, it can be seen that the dustproof substrate of Example 2 has a function of cutting light having a wavelength of 430 nm or less.

(Comparative Example 1)
In Comparative Example 1, Example 1 was used except that a quartz substrate having a thickness of 2.3 mm was used as the dustproof substrate.
In the same manner as described above, the spectrum after the light emitted from the light source transmitted through the dust-proof substrate was measured. The measurement results are shown in FIG.
As shown in FIG. 7, it can be seen that the dustproof substrate of Comparative Example 1 does not have a function of cutting light of a specific wavelength.

(Comparative Example 2)
In Comparative Example 2, the spectral spectrum after the light emitted from the light source was transmitted through the dustproof substrate in the same manner as in Example 1 except that crystallized glass (Neoceram) having a thickness of 1.1 mm was used as the dustproof substrate. Was measured. The measurement results are shown in FIG.
As shown in FIG. 8, the dust-proof substrate of Comparative Example 2 has a function of cutting light having a wavelength of 350 nm or less, but has a function of cutting light of wavelength 430 nm or less as compared with Example 1. Recognize.

This is because the thickness (1.1 mm) of the crystal glass constituting the dust-proof substrate is thinner than the thickness (2.3 mm) of the crystallized glass of Example 1, and light with a wavelength of 430 nm or less cannot be cut sufficiently. . On the other hand, in the dustproof substrate of Example 1, the thickness of the crystal glass is set to a thickness sufficient to cut light having a wavelength of 430 nm or less.

Next, as shown in Table 1, as a dustproof glass, a quartz substrate (synthetic quartz) with a plate thickness of 2.3 mm
(Sample 1), crystallized glass (neoceram) with a thickness of 1.1 mm (Sample 2), thickness 2.3 m
m crystallized glass (neoceram) (sample 3), an optical multilayer film laminated on a quartz substrate with a plate thickness of 1.0 mm (sample 4), crystallized glass with a plate thickness of 1.1 mm and a plate thickness of 1. For a sample obtained by laminating a laminate of optical multilayer films on a 0 mm quartz substrate (sample 5), the transmittance when light with a wavelength of 335 nm is incident from the front and an angle of 25 ° with respect to the front The transmittance when obliquely incident was measured. The results are summarized in Table 1.

As shown in Table 1, it can be seen that the dust-proof glasses of Samples 3 to 5 that satisfy the conditions of the present invention sufficiently cut light of 335 nm compared to Samples 1 and 2. Especially as dustproof glass,
It can be seen that Samples 3 and 5 using crystallized glass have an excellent cutting function for light incident from an oblique direction. Sample 5 can be thinned by combining crystallized glass and a quartz substrate laminated with an optical multilayer film.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal device 10 ... Element substrate 15 ... 1st alignment film 20 ... Opposite substrate 25 ... 2nd alignment film 30 ... Liquid crystal layer 50 ... Dust-proof substrate 51 ... Crystallized glass 52 ... Transparent substrate 53 ... Optical multilayer film 53a, 53b ... Dielectric film 100 ... projector 110 ... light source 330
R, 300G, 300B ... Light valve 600 ... Projection optical system

Claims (8)

From the light source, the first substrate on which the light emitted from the light source is incident, the second substrate sandwiched between the first substrate and the liquid crystal layer, and the light source of the first substrate A third substrate disposed on the light incident side of the liquid crystal device,
The third substrate transmits light in a wavelength band longer than a predetermined wavelength, which is a short wavelength among wavelength bands of incident light, to the liquid crystal layer side and the short wavelength. A liquid crystal device, wherein light having a wavelength band equal to or less than a predetermined wavelength is not transmitted to the liquid crystal layer side. The said 3rd board | substrate consists of crystallized glass by which thickness was set so that the light of the wavelength band below the said predetermined wavelength made into the said short wavelength may not be permeate | transmitted to the said liquid crystal layer side. The liquid crystal device according to 1. The liquid crystal device according to claim 1, wherein the third substrate has a structure in which an optical multilayer film is laminated on a surface of a transparent substrate. The liquid crystal device according to claim 1, wherein the third substrate has a structure in which crystallized glass and a transparent substrate on which an optical multilayer film is laminated are bonded to each other. 5. The liquid crystal device according to claim 1, wherein the third substrate has a wavelength band equal to or shorter than the predetermined wavelength, the wavelength being equal to or shorter than 350 nm. 5. The liquid crystal device according to claim 1, wherein the third substrate has a wavelength band equal to or shorter than the predetermined wavelength which is the short wavelength, and is a wavelength band equal to or less than 430 nm. The inorganic alignment film for controlling the alignment direction of the liquid crystal layer is provided on each of the surfaces of the first substrate and the second substrate facing the liquid crystal layer, respectively. The liquid crystal device according to item. The liquid crystal device according to claim 1 is provided as a light valve that forms image light obtained by modulating the light according to image information, and has a projection optical system that projects the image light. Projector.

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