JP2009198638A - Wire grid type polarizing element, method for manufacturing the same, electrooptical apparatus and projection type display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire grid type polarizing element which can improve both transmittance and contrast, its manufacturing method, a liquid crystal apparatus equipped with the wire grid type polarizing element and a projection type display apparatus. <P>SOLUTION: In the wire grid type polarizing element 1, two or more rows of catalyst layers 21a are formed with film thickness of 3 to 10 nm on one substrate surface 15 of a light translucent substrate 10 such as quartz glass and heat-resistant glass and further a light shielding grid 25a is formed on a top layer of the catalyst layer 21a. The light shielding grid 25a is a carbon nanotube layer of 35 to 350 nm film thickness and can be obtained by making carbon nanotube selectively grow on the top layer of the catalyst layer 21a by a plasma chemical vapor growth method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wire grid type polarizing element, a manufacturing method thereof, an electro-optical device, and a projection display device.

  As shown in FIGS. 11A and 11B, the wire grid type polarizing element includes a plurality of rows of metal gratings 20A as light shielding gratings on the substrate surface of the translucent substrate 10A, and the pitch ( If the period is shorter than the wavelength of the incident light, the polarized light component that vibrates in the direction perpendicular to the longitudinal direction of the metal grating 20A is transmitted, while the polarized light that vibrates in a direction parallel to the longitudinal direction of the metal grating 20A. The component is reflected.

  In the wire grid type polarizing element 1A, conventionally, after forming a metal film having a thickness of several hundreds of nanometers on the surface of the translucent substrate 10A, a groove-like opening is formed on the surface of the metal film in a region where the metal lattice 20A is to be formed. The prepared etching mask is formed, and in this state, the metal film is patterned to produce the mask.

In forming the etching mask, after applying a resin to the surface of the metal film, the concavo-convex pattern formed on the mold member is transferred to form a resist having a groove-like opening in the region where the metal lattice 20A is to be formed. A method for obtaining a mask has been proposed (see Patent Document 1).
JP 2006-84776 A

  In the wire grid type polarizing element 1A, the metal grating 20A reflects a part of the incident light. Therefore, even when the pitch of the metal grating 20A is shorter than the wavelength of the incident light, the metal grating 20A is perpendicular to the longitudinal direction of the metal grating 20A. The oscillating polarization component cannot be transmitted 100%. For this reason, the performance of the wire grid type polarizing element 1 </ b> A is expressed by “Transmittance” and “Contrast”. “Transmittance” is the transmittance of the polarization component that vibrates in the direction perpendicular to the longitudinal direction of the metal grating 20A, and “Contrast” is the polarization component that vibrates in the direction perpendicular to the longitudinal direction of the metal grating 20A. Is divided by the transmittance of the polarization component that vibrates in the direction parallel to the longitudinal direction of the metal grating 20A.

  Here, in order to increase “contrast”, the pitch of the metal grating 20A must be considerably shorter than the wavelength of incident light, and in order to increase “transmittance”, the width dimension of the metal grating 20A is reduced, In addition, the width dimension and the thickness dimension of the metal grid 20A must satisfy predetermined conditions.

  However, in the conventional method of forming the metal grating 20A by etching a thick metal film of several hundred nm, the width dimension and the thickness dimension of the metal grating 20A are affected by the etching accuracy with respect to the metal film. For this reason, for example, there is a restriction that the pitch of the metal grating 20A is limited to about 140 nm, and therefore, with regard to “transmittance” and “contrast”, it is the limit to obtain the performance shown in FIG. The “transmittance” has a problem that there is a large difference in the visible light band.

  Therefore, when a liquid crystal device using the conventional wire grid type polarizing element 1A is used as a light valve for red (R), green (G), and blue (B) light in a projection display device, red (R) However, there is a problem that the amount of light is reduced.

  In view of the above problems, an object of the present invention is to provide a wire grid type polarizing element capable of improving both “transmittance” and “contrast”, a manufacturing method thereof, and an electro-optical device including the wire grid type polarizing element. And a projection display device including the electro-optical device.

  In order to solve the above-described problem, in the present invention, in a wire grid type polarizing element including a plurality of rows of light shielding gratings on a substrate surface of a light-transmitting substrate, the substrate surface has a plurality of rows along the light shielding gratings. A catalyst layer is formed, and a carbon nanotube layer constituting the light-shielding lattice is laminated on the catalyst layer.

  Further, in the present invention, in the method of manufacturing a wire grid type polarizing element provided with a plurality of rows of light shielding grids on the substrate surface of the translucent substrate, the plurality of rows of light shielding grids are to be formed in the region to be formed with respect to the substrate surface. A catalyst layer forming step of forming a plurality of rows of catalyst layers along the carbon nanotube layer, and a carbon nanotube layer forming the light shielding lattice by selectively growing carbon nanotubes in the thickness direction on the catalyst layer And a forming step.

  In the present invention, in the carbon nanotube layer forming step, the carbon nanotube layer is preferably selectively grown by a plasma chemical vapor deposition method.

  In the wire grid type polarizing element according to the present invention, a plurality of rows of catalyst layers are formed on the substrate surface of the translucent substrate, and a carbon nanotube layer constituting a light shielding lattice is selectively formed on the upper layer of the catalyst layer. Since it is configured, the width dimension and pitch of the light shielding grating are defined by the width dimension and pitch of the catalyst layer. Here, the catalyst layer only needs to be selectively grown by carbon nanotubes, and may be thin. Therefore, even when patterning is performed by etching, the catalyst layer can be patterned with high accuracy. Therefore, the width dimension of the catalyst layer can be reduced to less than 70 nm, for example, 35 nm, and the pitch of the catalyst layer can be decreased to less than 140 nm, for example, 70 nm. Therefore, the width dimension of the light shielding grating can be reduced to less than 70 nm, for example, 35 nm, and the pitch of the light shielding grating can be reduced to less than 140 nm, for example, 70 nm. Therefore, both “transmittance” and “contrast” of the wire grid type polarizing element can be improved. Further, since the light shielding grating is made of a carbon nanotube layer having light absorption, unlike the case where the light shielding grating is made of a metal grating, there is an advantage that stray light is not generated because there is no reflection of light.

  In the present invention, the catalyst layer includes, for example, iron (Fe), cobalt (Co), nickel (Ni), titanium (Ti), vanadium (V), manganese (Mn), copper (Cu), and chromium (Cr). First transition metals (3d transition elements) such as zinc (Zn), second transition metals (4d transition elements) such as molybdenum (Mo), zirconium (Zr), palladium (Pd), silver (Ag), tungsten ( Third transition metals (4f transition elements) such as W), tantalum (Ta), platinum (Pt), and hafnium (Hf) can be used. In particular, iron, cobalt, nickel, titanium, and alloys of these metals It is preferable to consist of a single layer film or a laminated film of a metal selected from In particular, when iron, cobalt, or nickel is used as the catalyst layer, adhesion is improved by forming titanium in the lower layer.

  In the present invention, the catalyst layer may have a thickness of 3 to 10 nm. In order to form such a catalyst layer, in the catalyst layer forming step, after forming a metal layer constituting the catalyst layer on the substrate surface, an etching mask is formed on the surface of the metal layer, and thereafter The catalyst layer is patterned by etching into the metal layer.

  In the present invention, the carbon nanotube layer may have a thickness of 35 to 350 nm.

  In the wire grid type polarizing element to which the present invention is applied, the transmittance of the polarization component that vibrates in the direction perpendicular to the longitudinal direction of the light shielding grating is 80% or more over the entire wavelength band of 460 nm to 780 nm. Can be achieved.

  The wire grid type polarizing element to which the present invention is applied can be used for an electro-optical device or the like. The electro-optical device includes a liquid crystal panel including an element substrate, a counter substrate disposed opposite to the element substrate, and a liquid crystal held between the counter substrate and the element substrate. The wire grid type polarizing element is disposed on at least one of both surfaces sandwiching the liquid crystal panel.

  In this case, it is preferable that the wire grid type polarizing element is integrally formed on at least one of the element substrate and the counter substrate.

  The electro-optical device to which the present invention is applied can be used as a display unit of an electronic device such as a mobile computer or a mobile phone, and can also be used as a light valve in a projection display device. A light source unit that causes light to be incident on the optical device; and a projection optical system that enlarges and projects light modulated by the electro-optical device. In the present invention, the configuration used in the projection display device in which the three electro-optical devices are respectively used as light valves corresponding to red (R), green (G), and blue (B) can be adopted. It is also possible to adopt a configuration in which the emitted light is optically modulated by a liquid crystal device incorporating a color filter and enlarged and projected by a projection optical system. In any of these projection type display devices, if a wire grid type polarizing element to which the present invention is applied is used, it has a high transmittance for any color light of red (R), green (G), and blue (B). Therefore, a color image with high quality can be displayed.

  Embodiments of the present invention will be described below. In the drawings to be referred to in the following description, the scales of the layers and the members are different from each other in order to make the layers and the members large enough to be recognized on the drawings. In the following description, common portions will be described with the same reference numerals so that the comparison with the configuration described with reference to FIG. 7 can be easily understood.

[Wire grid type polarizing element to which the present invention is applied]
(Structure of wire grid type polarization element)
1A, 1B, and 1C are a cross-sectional view, a plan view, and another wire grid type polarized light to which the present invention is applied, schematically showing the configuration of a wire grid type polarizing element to which the present invention is applied. It is sectional drawing which shows the structure of an element typically.

  1A and 1B, the wire grid type polarizing element 1 of this embodiment includes a plurality of rows of light shielding gratings 25a on one substrate surface 15 of a translucent substrate 10 such as quartz glass or heat resistant glass. Yes. In this embodiment, a plurality of rows of catalyst layers 21a are formed on the substrate surface 15 along the light shielding lattice 25a, and a carbon nanotube layer constituting the light shielding lattice 25a is laminated on the upper layer of the catalyst layer 21a. As shown in FIG. 1C, a metal oxide film such as a silicon oxide film or a metal nitride film such as a silicon nitride film is used so as to fill the upper layer side of the light shielding grating 25a and the space between the light shielding gratings 25a. The translucent protective film 28 may be formed. According to such a configuration, a smooth surface in which both the region where the light shielding grating 25a is formed and the region where the light shielding grating 25a is not formed is continuous is formed. It is composed.

  In this embodiment, the catalyst layer 21a includes iron (Fe), cobalt (Co), nickel (Ni), titanium (Ti), vanadium (V), manganese (Mn), copper (Cu), chromium (Cr), First transition metal (3d transition element) such as zinc (Zn), second transition metal (4d transition element) such as molybdenum (Mo), zirconium (Zr), palladium (Pd), silver (Ag), tungsten (W ), Platinum (Pt), hafnium (Hf), and other third transition metals (4f transition elements) can be used, in particular of metals selected from iron, cobalt, nickel, titanium, and alloys of these metals. A single layer film or a laminated film is preferably used. Here, when iron, cobalt, or nickel is used as the catalyst layer 21a, adhesion is improved by forming titanium in the lower layer.

  In this embodiment, the catalyst layer 21a has a film thickness of 3 to 10 nm, and the light-shielding grating 25a has a film thickness of 35 to 350 nm. Here, the thickness dimension, the width dimension, and the interval of the light shielding pattern including the light shielding grating 25a and the catalyst layer 21a are generally set to 1: 1: 1. In the present embodiment, the width dimension and interval of the light shielding grating 25a and the catalyst layer 21a are both 35 nm, and the pitch between the light shielding grating 25a and the catalyst layer 21a is 70 nm.

  In the wire grid type polarizing element 1 configured as described above, when the pitch (period) of the light shielding grating 25a is shorter than the wavelength of the incident light, a polarization component that vibrates in a direction perpendicular to the longitudinal direction of the light shielding grating 25a (for example, The P-polarized component is transmitted, while the polarized component that vibrates in the direction parallel to the longitudinal direction of the light shielding grating 25a (for example, the S-polarized component) is reflected.

(Manufacturing method of wire grid type polarization element 1)
Hereinafter, with reference to FIG. 2 and FIG. 3, the configuration of the wire grid type polarizing element 1 of the present embodiment will be described in detail while explaining the manufacturing method of the wire grid type polarizing element 1 of the present embodiment. 2A to 2H are process cross-sectional views illustrating a manufacturing method of the wire grid type polarizing element 1 to which the present invention is applied. FIG. 3 is an explanatory view schematically showing a configuration of a plasma chemical vapor deposition apparatus for selectively growing carbon nanotubes constituting the light-shielding grating 25a in the manufacturing process of the wire grid type polarizing element 1 of the present embodiment. .

  In order to manufacture the wire grid type polarizing element 1 of this embodiment, as shown in FIG. 2A, after preparing a translucent substrate 10 with smooth both surfaces, refer to FIGS. 2B to 2G. Then, the catalyst layer forming step described below is performed.

  In this catalyst layer forming step, first, as shown in FIG. 2B, iron, cobalt, nickel, titanium, etc. are applied to the substrate surface 15 of the translucent substrate 10 by a method such as sputtering or vacuum deposition. The metal film 21 is formed to a thickness of 3 to 10 nm. Here, in the case of using iron, cobalt, or nickel as the metal film 21, adhesion is improved by forming titanium in the lower layer.

  Next, a mask formation process for forming an etching mask on the surface of the metal film 21 is performed. For this purpose, a photosensitive resin 60 is applied to the surface of the metal film 21 as shown in FIG. 2C, and then the photosensitive resin 60 is exposed through an exposure mask 64 as shown in FIG. Let Next, the photosensitive resin 60 is developed and then baked, and as shown in FIG. 2E, an etching mask 61 having a groove-like opening 62 in the region where the metal film 21 is to be removed. (Resist mask) is formed. Here, since the opening width dimension of the groove-shaped openings 62 is 35 nm, and the interval between the portions located between the groove-shaped openings 62 is 35 nm, the pitch of the groove-shaped openings 62 is 70 nm. In FIG. 2E, the positive photosensitive resin 60 is irradiated with ultraviolet light through the exposure mask 64 to form the etching mask 61. However, extreme ultraviolet light may be used as the ultraviolet light. Instead of the ultraviolet light, the photosensitive resin may be exposed by an electron beam, an X-ray or the like. In this case, direct drawing may be performed without using the exposure mask 61.

  Next, as shown in FIG. 2F, etching is performed on the substrate surface 15 of the translucent substrate 10 while the etching mask 61 is formed on the surface of the metal film 21, and the metal films 21 are arranged in a plurality of rows. The catalyst layer 21a is patterned. As such etching, either dry etching or wet etching may be used.

  Next, as shown in FIG. 2 (g), after removing the etching mask 61 from the surface of the catalyst layer 21a, as shown in FIG. 2 (h), carbon nanotubes are formed in the thickness direction on the upper layer of the catalyst layer 21a. A carbon nanotube layer forming step of forming a carbon nanotube layer that selectively grows to constitute the light shielding lattice 25a is performed.

  In the carbon nanotube layer forming step, the light shielding lattice 25a (carbon nanotube layer) is selectively grown by plasma chemical vapor deposition using the plasma chemical vapor deposition apparatus 90 shown in FIG.

  A plasma enhanced chemical vapor deposition apparatus 90 illustrated in FIG. 3 is an electric field application type plasma CVD apparatus. Electrodes 92 and 93 are disposed in a chamber 91, and the translucent substrate 10 is placed on the electrode 92. The The chamber 91 has a carbon supply gas made of methane, ethane, ethylene, acetylene, or a mixed gas thereof, a reaction gas introduction path 97 for introducing hydrogen gas, an exhaust vacuum pump 94, and a microwave plasma generator 96. A DC power supply 95 is connected to the electrodes 92 and 93. In such a plasma chemical vapor deposition apparatus 90, for example, methane gas and hydrogen gas are introduced into the chamber 91, and plasma is generated to form carbon nanotubes by plasma chemical vapor deposition. At that time, for example, the substrate temperature is set to 450 ° C. or higher, the pressure is set to several 10 to 100 Pa, the applied voltage to the substrate is set to several tens V or more, and carbon nanotubes are selectively grown in the thickness direction on the catalyst layer 21a. Then, the light shielding grid 25a is formed. As a result, the wire grid type polarizing element 1 described with reference to FIG. 1 can be obtained.

  As shown in FIG. 1C, when the protective film 28 is formed, it is made of a metal oxide film such as a silicon oxide film or a metal nitride film such as a silicon nitride film so as to cover the light shielding grating 25a. After the light-transmitting film is formed, a polishing process may be performed on the surface of the light-transmitting film. Chemical mechanical polishing can be used as a polishing process, and in such chemical mechanical polishing, a smooth polished surface is obtained at high speed by the action of chemical components contained in the polishing liquid and the relative movement of the abrasive and the light-transmitting substrate 10. Can do. More specifically, in a polishing apparatus, while rotating a surface plate on which a polishing cloth (pad) made of a nonwoven fabric, polyurethane foam, porous fluororesin, or the like is attached, and a holder that holds the translucent substrate 10 are relatively rotated. Polish. At that time, for example, an abrasive containing cerium oxide particles having an average particle diameter of 0.01 to 20 μm, an acrylate derivative as a dispersant, and water is supplied between the polishing cloth and the translucent substrate 10.

(Another manufacturing method of the wire grid type polarizing element 1)
With reference to FIG. 4, another manufacturing method of the wire grid type polarizing element 1 of this form is demonstrated. 4A to 4H are process cross-sectional views showing another method for manufacturing the wire grid type polarizing element 1 to which the present invention is applied.

  In order to manufacture the wire grid type polarizing element 1 of this embodiment, as shown in FIG. 4A, after preparing a translucent substrate 10 having smooth both surfaces, refer to FIGS. 4B to 4G. Then, the catalyst layer forming step described below is performed.

  In this catalyst layer forming step, first, as shown in FIG. 4B, iron, cobalt, nickel, titanium, etc. are applied to the substrate surface 15 of the translucent substrate 10 by a method such as sputtering or vacuum deposition. The metal film 21 is formed to a thickness of 3 to 10 nm.

  Next, a mask formation process for forming an etching mask on the surface of the metal film 21 is performed. 4 (c), after applying a photosensitive resin layer as a mask material layer 65 to the surface of the metal film 21, as shown in FIG. 4 (c), a nanoprint mold member is used. In 70, the molding surface provided with the protrusions 71 is pressed against the mask material layer 65 to transfer the formation pattern of the protrusions 71 to the mask material layer 65. Meanwhile, the mask material layer 65 is cured by irradiating the mask material layer 65 with ultraviolet light from the translucent substrate 10 side. Next, the mold member 70 is pulled away from the translucent substrate 10 side. As a result, as shown in FIGS. 4D and 4E, an etching mask 66 having a groove-shaped opening 67 that is pressed and thinned by the protrusion 71 is formed on the surface of the metal film 21. . Here, both the protrusion 71 of the mold member 70 and the groove-shaped opening 67 of the etching mask 66 correspond to the region where the metal film 21 is to be removed. Here, since the opening width dimension of the groove-like opening 67 is 35 nm and the interval between the portions located between the groove-like openings 67 is 35 nm, the pitch of the groove-like openings 67 is 70 nm. According to such a method, there is an advantage that when the etching mask 66 is formed, a process that requires a great amount of labor such as exposure and development and an expensive apparatus is not required. When a thermosetting resin layer is formed as the mask material layer 65, the mask material layer 65 is cured by heating while pressing the mold member 70 against the mask material layer 65.

  Next, the metal film 21 is etched while the etching mask 66 is formed on the surface of the metal film 21. As such etching, dry etching is performed. As a result, while the etching mask 66 is being etched, the metal film 21 is etched in a portion corresponding to the groove-shaped opening 67 of the etching mask 66, and as shown in FIG. 21a is formed.

  Next, as shown in FIG. 4G, after removing the etching mask 61 from the surface of the catalyst layer 21a, the carbon nanotubes are formed in the thickness direction on the upper layer of the catalyst layer 21a as shown in FIG. 4H. A carbon nanotube layer forming step of forming a carbon nanotube layer that selectively grows to constitute the light shielding lattice 25a is performed.

  In the carbon nanotube layer forming step, the light shielding lattice 25a (carbon nanotube layer) is selectively grown by plasma chemical vapor deposition using the plasma chemical vapor deposition apparatus shown in FIG.

  Even when the manufacturing method W is adopted, as shown in FIG. 1C, when the protective film 28 is formed, a metal oxide film such as a silicon oxide film, a silicon nitride film, or the like is formed so as to cover the light shielding grating 25a. After forming a light-transmitting film made of a metal nitride film or the like, a polishing process may be performed on the surface of the light-transmitting film.

(Main effects of this form)
FIG. 5 is a graph showing transmittance characteristics and contrast characteristics of a wire grid type polarizing element to which the present invention is applied.

  As described above, in the wire grid type polarizing element 1 to which the present invention is applied, a plurality of rows of catalyst layers 21a are formed on the substrate surface 15 of the translucent substrate 10, and the light shielding grating 25a is formed on the upper layer of the catalyst layer 21a. Therefore, the width dimension and pitch of the light shielding grating 25a are defined by the width dimension and pitch of the catalyst layer 21a. Here, the catalyst layer 21a may be thin as long as carbon nanotubes are selectively grown. Therefore, even when the catalyst layer 21a is patterned by etching, the catalyst layer 21a can be patterned with high accuracy. Therefore, the width dimension of the catalyst layer 21a can be reduced to less than 70 nm, for example, 35 nm, and the pitch of the catalyst layer 21a can be decreased to less than 140 nm, for example, 70 nm. Accordingly, the width dimension of the light shielding grating 25a can be reduced to less than 70 nm, for example, 35 nm, and the pitch of the light shielding grating 25a can be reduced to less than 140 nm, for example, 70 nm. Further, the ratio of the thickness dimension to the width dimension of the catalyst layer 21a and the light-shielding grating 25a can be set to approximately 1: 1. Therefore, both “transmittance” and “contrast” of the wire grid type polarizing element 1 can be improved.

  Therefore, the wire grid type polarizing element 1 of the present embodiment has transmittance characteristics and contrast characteristics as shown in FIG. 5, and has a polarization component that vibrates in a direction perpendicular to the longitudinal direction of the light shielding grating 25a. The “transmittance” is 80% or more over the entire wavelength band from 460 nm to 780 nm. Moreover, the wire grid type polarizing element 1 of this embodiment vibrates the transmittance of the polarization component that vibrates in the direction perpendicular to the longitudinal direction of the light shielding grating 25a in a direction parallel to the longitudinal direction of the light shielding grating 25a. The value (contrast) divided by the transmittance of the polarization component is 170000 or more over the entire wavelength band from 460 nm to 780 nm.

  Therefore, a liquid crystal device is configured using the wire grid type polarizing element 1 of the present embodiment, and the liquid crystal device is used as a color display unit of an electronic device such as a mobile computer or a mobile phone, or a projection for color display described later. When used for a light valve of a type display device, a high transmittance can be obtained for any color light of red (R), green (G), and blue (B), so that a high-quality color image is displayed. be able to.

  Further, in the wire grid type polarizing element 1 of this embodiment, since the light shielding grating 25a is made of a carbon nanotube layer having light absorption, unlike the case where the light shielding grating is made of a metal grating, there is no reflection of light. There is also an advantage that does not occur.

[Other wire grid type polarizing elements]
In the wire grid type polarizing element 1 described with reference to FIG. 1, an antireflection layer may be formed on both surfaces thereof, and the antireflection layer includes, for example, five layers of a silicon oxide film and a titanium oxide film. Can be realized. The wire grid type polarizing element 1 configured as described above has excellent transmittance characteristics.

[Application Example 1 to Projection Display Device]
(Configuration of projection display device)
FIGS. 6A and 6B are a first example of a projection display device using a liquid crystal device (electro-optical device) using a wire grid type polarizing element according to the present invention as a light valve, and the projection display. It is a schematic block diagram of the light valve etc. which were used for the apparatus.

  The projection type display device 110 shown in FIGS. 6A and 6B irradiates light onto a screen 111 (projected surface) provided on the viewer side, and observes the light reflected by the screen 111. This is a liquid crystal projector. The projection display device 110 includes a light source unit 150 including a light source 112 and dichroic mirrors 113 and 114, liquid crystal light valves 100 (R), (G), and (B) described later, a projection optical system 118, and a cross A dichroic prism 119 (color synthesis optical system) and a relay system 120 are provided.

  The liquid crystal light valves 100 (R), (G), and (B) each include a liquid crystal panel 101 (R), (G), and (B). Since the liquid crystal panels 101 (R), (G), and (B) are well-known ones, a detailed description thereof is omitted, but the element substrate 71 on which pixel electrodes and pixel switching elements are formed, and a common electrode The counter substrate 72 thus formed is bonded with a sealant 79 through a predetermined gap, and the liquid crystal 70 is held in a region surrounded by the sealant 79 between the element substrate 71 and the counter substrate 72.

  In the light source unit 150, the light source 112 is configured by an ultrahigh pressure mercury lamp that supplies light including red light, green light, and blue light. The dichroic mirror 113 is configured to transmit red light from the light source 112 and reflect green light and blue light. The dichroic mirror 114 is configured to transmit blue light and reflect green light among green light and blue light reflected by the dichroic mirror 113. Thus, the dichroic mirrors 113 and 114 constitute a color separation optical system that separates the light emitted from the light source 112 into red light, green light, and blue light.

  Here, between the dichroic mirror 113 and the light source 112, an integrator 121 and a polarization conversion element 122 are arranged in order from the light source 112. The integrator 121 is configured to make the illuminance distribution of the light emitted from the light source 112 uniform. Further, the polarization conversion element 122 is configured to change the light from the light source 112 into polarized light having a specific vibration direction such as s-polarized light.

  The liquid crystal light valve 100 (R) is a transmissive liquid crystal device (electro-optical device) that modulates red light transmitted through the dichroic mirror 113 and reflected by the reflecting mirror 123 according to an image signal, and has a λ / 2 phase difference. A plate 102 (R), an incident side polarizing plate 108 (R), a liquid crystal panel 101 (R), and an output side polarizing plate 105 (R) are provided. In addition, an incident-side dustproof glass 103 (R) and an emission-side dustproof glass 104 (R) are attached to both surfaces of the liquid crystal panel 101 (R), respectively. The dust-proof glass prevents dust and the like from appearing on the projected image.

  The red light incident on the liquid crystal light valve 100 (R) remains as s-polarized light because the polarization of the light does not change even if it passes through the dichroic mirror 113. The λ / 2 retardation film 102 (R) is an optical element that converts s-polarized light incident on the liquid crystal light valve 100 (R) into p-polarized light. The incident-side polarizing plate 108 (R) blocks the s-polarized light and transmits the p-polarized light and makes it incident on the liquid crystal panel 101 (R). The liquid crystal panel 101 (R) modulates the p-polarized light by modulating the image signal. Conversion to s-polarized light (circularly polarized light or elliptically polarized light if it is halftone). The exit-side polarizing plate 105 (R) is a polarizing plate that blocks p-polarized light and transmits s-polarized light. Accordingly, the liquid crystal light valve 100 (R) is configured to modulate the red light in accordance with the image signal and emit the modulated red light toward the cross dichroic prism 119.

  The liquid crystal light valve 100 (G) is a transmissive liquid crystal device (electro-optical device) that modulates green light reflected by the dichroic mirror 114 after being reflected by the dichroic mirror 113 in accordance with an image signal. Similarly to (R), an incident side polarizing plate 108 (G), a liquid crystal panel 101 (G), and an output side polarizing plate 105 (G) are provided. In addition, an incident-side dustproof glass 103 (G) and an emission-side dustproof glass 104 (G) are attached to both surfaces of the liquid crystal panel 101 (G), respectively.

  The green light incident on the liquid crystal light valve 100 (G) is s-polarized light that is reflected by the dichroic mirrors 113 and 114 and incident. The incident-side polarizing plate 108 (G) blocks the p-polarized light and transmits the s-polarized light and makes it incident on the liquid crystal panel 101 (G). The liquid crystal panel 101 (G) modulates the s-polarized light by modulating the image signal. It is configured to convert to p-polarized light (circularly polarized light or elliptically polarized light if it is halftone). The exit-side polarizing plate 105 (G) is a polarizing plate that blocks s-polarized light and transmits p-polarized light. Accordingly, the liquid crystal light valve 100 (G) is configured to modulate green light in accordance with an image signal and emit the modulated green light toward the cross dichroic prism 119.

  The liquid crystal light valve 100 (B) is a transmissive liquid crystal device (electro-optical device) that modulates blue light reflected by the dichroic mirror 113 and transmitted through the dichroic mirror 114 and then through the relay system 120 in accordance with an image signal. Yes, as with the liquid crystal light valve 100 (R), a λ / 2 retardation film 102 (B), an incident side polarizing plate 108 (B), a liquid crystal panel 101 (B), and an output side polarizing plate 105 (B) are provided. ing. In addition, an incident-side dustproof glass 103 (B) and an emission-side dustproof glass 104 (B) are attached to both surfaces of the liquid crystal panel 101 (B), respectively.

  The blue light incident on the liquid crystal light valve 100 (B) is reflected by two reflecting mirrors 125a and 125b (to be described later) of the relay system 120 after being reflected by the dichroic mirror 113 and transmitted through the dichroic mirror 114. It has become. The λ / 2 retardation film 102 (B) is an optical element that converts s-polarized light incident on the liquid crystal light valve 100 (B) into p-polarized light. The incident-side polarizing plate 108 (B) blocks the s-polarized light and transmits the p-polarized light and makes it incident on the liquid crystal panel 101 (B). The liquid crystal panel 101 (B) modulates the p-polarized light by modulating the image signal. It is converted into s-polarized light (circularly polarized light or elliptically polarized light if it is halftone). The exit-side polarizing plate 105 (B) is a polarizing plate that blocks p-polarized light and transmits s-polarized light. Accordingly, the liquid crystal light valve 100 (B) is configured to modulate blue light in accordance with an image signal and emit the modulated blue light toward the cross dichroic prism 119.

  The relay system 120 includes relay lenses 124a and 124b and reflection mirrors 125a and 125b. The relay lenses 124a and 124b are provided to prevent light loss due to a long blue light path. Here, the relay lens 124a is disposed between the dichroic mirror 114 and the reflection mirror 125a. The relay lens 124b is disposed between the reflection mirrors 125a and 125b. The reflection mirror 125a is disposed so as to reflect the blue light transmitted through the dichroic mirror 114 and emitted from the relay lens 124a toward the relay lens 124b. The reflection mirror 125b is disposed so as to reflect the blue light emitted from the relay lens 124b toward the liquid crystal light valve 100 (B).

  The cross dichroic prism 119 is a color combining optical system in which two dichroic films 119a and 119b are arranged orthogonally in an X shape. The dichroic film 119a is a film that reflects blue light and transmits green light, and the dichroic film 119b is a film that reflects red light and transmits green light. Accordingly, the cross dichroic prism 119 combines the red light, the green light, and the blue light modulated by the liquid crystal light valves 100 (R), (G), and (B), respectively, and emits the light toward the projection optical system 118. Is configured to do.

  The light incident on the cross dichroic prism 119 from the liquid crystal light valves 100 (R) and (B) is s-polarized light, and the light incident on the cross dichroic prism 119 from the liquid crystal light valve 100 (G) is p-polarized light. In this way, by making the light incident on the cross dichroic prism 119 into different types of polarized light, the light incident from the liquid crystal light valves 100 (R), (G), and (B) in the cross dichroic prism 119 is effectively combined. it can. Here, in general, the dichroic films 119a and 119b are excellent in the reflection characteristics of s-polarized light. For this reason, red light and blue light reflected by the dichroic films 119a and 119b are s-polarized light, and green light transmitted through the dichroic films 119a and 119b is p-polarized light. The projection optical system 118 has a projection lens (not shown) and is configured to project the light combined by the cross dichroic prism 119 onto the screen 111.

(Application of wire grid type polarizing element 1 to projection type display device)
In the projection type display device 110 configured as described above, the wire grid type polarizing element 1 described with reference to FIGS. 1 to 5 is the incident side polarization of the liquid crystal light valves 100 (R), (G), and (B). It can be used as the plate 108 (R), (G), (B).

  In addition, the wire grid type polarizing element 1 described with reference to FIGS. 1 to 5 is different from the case where the light shielding grating is made of a metal lattice because the light shielding grating 25a is made of a carbon nanotube layer having light absorption. Since there is no reflection of light, no stray light is generated. Therefore, the wire grid type polarizing element 1 described with reference to FIG. 1 to FIG. 5 includes the liquid crystal light valves 100 (R), (G), and (B) emitting side polarizing plates 105 (R), (G). , (B), and in this case, the light reflected by the output-side polarizing plates 105 (R), (G), (B) is applied to the liquid crystal panels 101 (R), (G), (B). It does not enter as stray light. Moreover, the wire grid type polarizing element 1 demonstrated with reference to FIGS. 1-5 is the incident-side polarizing plate 108 (R), (G) of liquid crystal light valve 100 (R), (G), (B), It can be used as (B) and output side polarizing plate 105 (R), (G), (B).

[Application Example 2 to Projection Display Device]
FIGS. 7A and 7B show a second example of a projection display device using a liquid crystal device (electro-optical device) using a wire grid type polarizing element according to the present invention as a light valve, and the projection display. It is a schematic block diagram of the light valve etc. which were used for the apparatus. 7A and 7B has a basic configuration similar to that of the projection display device 110 described with reference to FIG. The same reference numerals are given and description thereof is omitted.

  In the liquid crystal light valves 100 (R), (G), and (B) used in the projection display device 110 shown in FIGS. 6 (a) and 6 (b), the liquid crystal panels 101 (R), (G), and (B) are used. In addition to the liquid crystal panels 101 (R), (G), and (B), the incident side polarizing plates 108 (R), (G), and (B) and the outgoing side polarizing plates 105 (R), ( G) and (B) are arranged, but in the projection type display device 110 shown in FIGS. 7A and 7B, the wire grid type polarizing element 1 described with reference to FIGS. The incident-side polarizing plates 108 (R), (G) formed integrally with the counter substrate 72 of the liquid crystal panels 101 (R), (G), (B) and described with reference to FIGS. ) And (B). For this reason, in the liquid crystal light valves 100 (R), (G), and (B), the incident-side polarizing plates 108 (R) and (G) from the light incident side of the liquid crystal panels 101 (R), (G), and (B). ) And (B) can be omitted, so that the number of parts can be reduced. Such a configuration can be realized by configuring the counter substrate 72 using the translucent substrate 10 shown in FIG. 1 as a base material.

[Application Example 3 to Projection Display Device]
FIGS. 8A and 8B show a third example of a projection display device using a liquid crystal device (electro-optical device) using a wire grid type polarizing element according to the present invention as a light valve, and the projection display. It is a schematic block diagram of the light valve etc. which were used for the apparatus. The basic configuration of the projection display device 110 shown in FIGS. 8A and 8B is the same as that of the projection display device 110 described with reference to FIG. The same reference numerals are given and description thereof is omitted.

  In the wire grid type polarizing element 1 described with reference to FIGS. 1 to 5, since the light shielding grating 25a is made of a carbon nanotube layer having light absorption, unlike the case where the light shielding grating is made of a metal grating, Since there is no reflection, no stray light is generated. Therefore, in the projection type display device 110 shown in FIGS. 7A and 7B, the wire grid type polarizing element 1 described with reference to FIGS. 1 to 5 includes the liquid crystal panels 101 (R) and (G). , (B) are formed integrally with the element substrate 71 and function as the output side polarizing plates 108 (R), (G), (B) described with reference to FIGS. For this reason, in the liquid crystal light valves 100 (R), (G), and (B), the light exit side polarizing plates 105 (R) and (G) from the light exit side of the liquid crystal panels 101 (R), (G), and (B). ) And (B) can be omitted, so that the number of parts can be reduced. Such a configuration can be realized by configuring the element substrate 71 using the translucent substrate 10 shown in FIG. 1 as a base material.

[Application Example 4 to Projection Display Device]
FIGS. 9A and 9B show a fourth example of a projection display device using a liquid crystal device (electro-optical device) using a wire grid type polarizing element according to the present invention as a light valve, and the projection display. It is a schematic block diagram of the light valve etc. which were used for the apparatus. The basic configuration of the projection display device 110 shown in FIGS. 9A and 9B is the same as that of the projection display device 110 described with reference to FIG. The same reference numerals are given and description thereof is omitted.

  In the projection display device 110 shown in FIGS. 9A and 9B, the wire grid type polarizing element 1 described with reference to FIGS. 1 to 5 includes the liquid crystal panels 101 (R), (G), and (B). ) And the opposing substrate 72, and functions as the incident-side polarizing plates 108 (R), (G), and (B) described with reference to FIGS. 6 (a) and 6 (b). For this reason, in the liquid crystal light valves 100 (R), (G), and (B), the incident-side polarizing plates 108 (R) and (G) from the light incident side of the liquid crystal panels 101 (R), (G), and (B). ) And (B) can be omitted. Moreover, the wire grid type polarizing element 1 demonstrated with reference to FIGS. 1-5 is integrally formed with the element substrate 71 of liquid crystal panel 101 (R), (G), (B), and FIG. 6 (a). , (B) functions as the output side polarizing plate 108 (R), (G), (B). For this reason, in the liquid crystal light valves 100 (R), (G), and (B), the light exit side polarizing plates 105 (R) and (G) from the light exit side of the liquid crystal panels 101 (R), (G), and (B). ) And (B) can be omitted.

[One light valve type projection display]
FIG. 10 is a schematic configuration diagram of a projection display device using a liquid crystal device (electro-optical device) using the wire grid type polarizing element according to the present invention as a light valve.

  In the projection type display device 210 shown in FIG. 10, a color image is projected and displayed on the screen 211 by one liquid crystal device 100 (electro-optical device). That is, the projector 210 includes a light source unit 240 including a white light source 212, an integrator 221, and a polarization conversion element 222, a liquid crystal device 1001, and a projection optical system 218. In the liquid crystal device 100, the first polarizing plate 216a and the second polarizing plate 216b are disposed on both sides of the liquid crystal panel 100a with a built-in color filter.

  In the projector 110 configured as described above, when the wire grid type polarizing element 1 described with reference to FIGS. 1 to 5 is used as the first polarizing plate 216a and the second polarizing plate 116b, red (R), green ( Since a high transmittance can be obtained for any color light of G) and blue (B), a high-quality color image can be displayed.

  Also in the projection display device 210 having such a configuration, if the wire grid type polarizing element 1 described with reference to FIGS. 1 to 5 is formed integrally with the element substrate and / or the counter substrate of the liquid crystal panel 100a, the number of components is increased. Can be reduced.

(A), (b), (c) is a cross-sectional view, a plan view schematically showing the configuration of a wire grid type polarizing element to which the present invention is applied, and another wire grid type polarizing element to which the present invention is applied. It is sectional drawing which shows a structure typically. (A)-(h) is process sectional drawing which shows the manufacturing method of the wire grid type polarizing element to which this invention is applied. It is explanatory drawing which shows typically the structure of the plasma chemical vapor deposition apparatus for selectively growing the carbon nanotube which comprises a light-shielding grating | lattice among the manufacturing processes of the wire grid type polarizing element to which this invention is applied. It is process sectional drawing which shows another manufacturing method of the wire grid type polarizing element to which this invention is applied. It is a graph which shows the transmittance | permeability characteristic and contrast characteristic of the wire grid type polarizing element to which this invention is applied. (A), (b) is a first example of a projection display device using a liquid crystal device (electro-optical device) using a wire grid type polarizing element according to the present invention as a light valve, and the projection display device. It is a schematic block diagram of the used light valve. (A), (b) is the 2nd example of the projection type display apparatus which used the liquid crystal device (electro-optical apparatus) using the wire grid type polarizing element concerning this invention as a light valve, and this projection type display apparatus. It is a schematic block diagram of the used light valve. (A), (b) is a third example of a projection display device using a liquid crystal device (electro-optical device) using a wire grid type polarizing element according to the present invention as a light valve, and this projection display device. It is a schematic block diagram of the used light valve. (A), (b) is a fourth example of a projection display device using a liquid crystal device (electro-optical device) using a wire grid type polarizing element according to the present invention as a light valve, and this projection display device. It is a schematic block diagram of the used light valve. It is a schematic block diagram of the projection type display apparatus which used the liquid crystal device (electro-optical apparatus) using the wire grid type polarizing element which concerns on this invention as a light valve. (A), (b) is sectional drawing and the top view which respectively show the structure of the conventional wire grid type polarizing element typically. It is a graph which shows the transmittance | permeability characteristic and contrast characteristic of the conventional wire grid type polarizing element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wire grid type polarizing element 10 ... Translucent substrate 15 ... Substrate surface 21a ... Catalyst layer 25a ... Light-shielding grating

Claims (13)

In the wire grid type polarizing element provided with a plurality of rows of light shielding gratings on the substrate surface of the translucent substrate,
On the substrate surface, a plurality of rows of catalyst layers are formed along the light-shielding grid,
A wire grid type polarizing element, wherein a carbon nanotube layer constituting the light-shielding lattice is laminated on an upper layer of the catalyst layer.   The wire grid type polarizing element according to claim 1, wherein the catalyst layer comprises a single layer film or a laminated film of a metal selected from iron, cobalt, nickel, titanium, and an alloy of these metals.   The wire grid type polarizing element according to claim 1, wherein the catalyst layer has a thickness of 3 to 10 nm.   4. The wire grid type polarizing element according to claim 1, wherein the carbon nanotube layer has a thickness of 35 to 350 nm. 5.   5. The transmittance of the polarization component that vibrates in a direction perpendicular to the longitudinal direction of the light-shielding grating is 80% or more over the entire wavelength band from 460 nm to 780 nm. The wire grid type polarizing element according to item. In the manufacturing method of the wire grid type polarization element provided with a plurality of rows of light shielding grids on the substrate surface of the translucent substrate,
A catalyst layer forming step of forming a plurality of rows of catalyst layers along a region where the plurality of rows of light shielding grids are to be formed with respect to the substrate surface;
A carbon nanotube layer forming step of forming a carbon nanotube layer constituting the light-shielding lattice by selectively growing carbon nanotubes in a thickness direction on the catalyst layer;
The manufacturing method of the wire grid type polarizing element characterized by having.   The method of manufacturing a wire grid type polarizing element according to claim 6, wherein in the carbon nanotube layer forming step, the carbon nanotube layer is selectively grown by a plasma chemical vapor deposition method.   The wire grid type polarization according to claim 6 or 7, wherein the catalyst layer comprises a single layer film or a laminated film of a metal selected from iron, cobalt, nickel, titanium, and an alloy of these metals. Device manufacturing method. The catalyst layer has a thickness of 3 to 10 nm,
In the catalyst layer forming step, after forming a metal layer constituting the catalyst layer on the substrate surface, an etching mask is formed on the surface of the metal layer, and then the metal layer is etched to etch the catalyst. The method of manufacturing a wire grid type polarizing element according to any one of claims 6 to 8, wherein the layer is formed by patterning.   The method for manufacturing a wire grid type polarizing element according to any one of claims 6 to 9, wherein the carbon nanotube layer has a thickness of 35 to 350 nm. An electro-optical device comprising the wire grid type polarizing element according to any one of claims 1 to 5,
A liquid crystal panel comprising: an element substrate; a counter substrate disposed opposite to the element substrate; and a liquid crystal held between the counter substrate and the element substrate.
The electro-optical device, wherein the wire grid type polarizing element is disposed on at least one side of both surfaces of the liquid crystal panel.   The electro-optical device according to claim 11, wherein the wire grid type polarization element is integrally formed on at least one of the element substrate and the counter substrate. A projection display device comprising the electro-optical device according to claim 11 as a light valve,
A light source unit for causing light to enter the electro-optical device;
A projection optical system for enlarging and projecting light modulated by the electro-optical device;
A projection display device characterized by comprising:

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