JP2011008172A - Polarizing element and manufacturing method therefor, projection type display, liquid crystal device, and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire grid type polarizing element that improves balance between transmission characteristics and reflection characteristics.SOLUTION: The wire grid type polarizing element includes :a substrate 11; a plurality of first protrusion parts 13a provided in a substantially stripe shape in plan view, on the substrate 11; a pair of metal fine wires 14 provided to be extended in a substantially stripe shape in plan view, along the same directions as extension directions of the first protrusion parts 13a, on each of the first protrusion parts 13a; and second protrusion parts 13b having an area between the paired metal fine wires 14 which is embedded lower than upper ends 14b of the metal fine wires 14, between the paired metal fine wires 14 on each of the first protrusion parts 13a.

Description

  The present invention relates to a polarizing element, a method for manufacturing the polarizing element, a projection display device, a liquid crystal device, and an electronic apparatus.

  A liquid crystal device is used as a light modulation device of various electro-optical devices. As a structure of a liquid crystal device, a structure in which a liquid crystal layer is sandwiched between a pair of substrates arranged opposite to each other is widely known, and a polarizing element for inputting predetermined polarized light into the liquid crystal layer, a voltage A configuration including an alignment film that controls the alignment of liquid crystal molecules when no voltage is applied is common.

  As a polarizing element, a film-type polarizing element manufactured by orienting iodine or a dichroic dye in a stretching direction by stretching a resin film containing iodine or a dichroic dye in one direction, or on a transparent substrate There is known a wire grid type polarizing element formed by laying nanoscale metal wires on the surface.

  Since the wire grid polarizing element is composed of an inorganic material, it has the feature of being excellent in heat resistance, and is particularly suitably used in a place where heat resistance is required. For example, it is suitably used as a polarizing element for a light valve of a liquid crystal projector exposed to light from a high-output light source. As such a wire grid type polarization element, for example, techniques disclosed in Patent Documents 1 and 2 are disclosed.

  In Patent Document 1, in a wire grid polarizing element having a metal thin wire having a cross-sectional shape with a large aspect ratio, a dielectric thin wire extending in parallel with the metal thin wire is formed in contact with the side surface of the metal thin wire, and the dielectric thin wire is formed. The structure which uses and supports a metal fine wire is proposed. According to this configuration, the thin metal wires are not easily collapsed, and high reliability can be obtained.

  Patent Document 2 proposes a configuration in which conductive elements are formed on ribs formed in a stripe shape on the surface of a substrate. According to this configuration, the optical constant (dielectric constant) decreases in the layer below the conductive element (on the rib side), thereby shifting the resonant wavelength of the wire grid polarizing element by a short wavelength, and with respect to TM light in the visible light region. The light transmittance (Tp) can be increased and the light transmittance (Tc) with respect to TE light can be decreased.

JP 2008-145581 A Special table 2003-502708 gazette

  However, for the purpose of improving the brightness of devices using wire grid polarizing elements, such as projectors and liquid crystal devices, wire grids exhibiting better optical characteristics than the physical properties of wire grid polarizing elements having the configuration shown in the above document. There is a need for polarizing elements.

  In order to improve the luminance of light through the wire grid polarizing element, in the case of a reflective wire grid polarizing element, it is required to improve the balance between transmission characteristics and reflection characteristics. That is, a high TM light transmittance and a low TE light transmittance are required. By adopting a wire grid polarizing element with improved balance, for example, as a polarizing element for a liquid crystal light valve of a liquid crystal projector, it is possible to improve luminance and realize high-contrast image display.

  The present invention has been made in view of such circumstances, and provides a wire grid type polarizing element in which the balance between transmission characteristics and reflection characteristics, which are main optical characteristics, is improved, and a method for manufacturing the same. Objective. It is another object of the present invention to provide a projection display device, a liquid crystal device, and an electronic apparatus that are provided with such a polarizing element and have high display quality and excellent reliability.

  In order to solve the above-described problems, a polarizing element of the present invention includes a substrate, a plurality of first dielectric layers provided on the substrate in a substantially stripe shape in plan view, and on each of the first dielectric layers. A pair of fine metal wires provided extending in a substantially stripe shape in plan view in the same direction as the direction in which the first dielectric layer extends, and the pair of metals on each of the first dielectric layers And a second dielectric layer provided between the thin wires so that a region between the pair of thin metal wires is buried below the upper end of the thin metal wires.

  According to this configuration, since the fine metal wires are supported by the second dielectric layer, the fine metal wires are unlikely to fall down, and damage can be suppressed. In addition, since the region between the first dielectric layers (hereinafter referred to as the groove) is deeper than the lower end of the fine metal wire, the substrate material disposed around the fine metal wire can be reduced, and the characteristics against transmitted light are improved. Can be made. Therefore, it can be set as the polarizing element which has a favorable optical characteristic.

In the present invention, the height from the upper end of the thin metal wire to the upper end of the second dielectric layer is equal to the height from the lower end of the fine metal wire to the bottom of the region between the first dielectric layers. be able to.
In the present invention, the height from the lower end of the thin metal wire to the bottom of the region between the first dielectric layers is larger than the height from the upper end of the thin metal wire to the upper end of the second dielectric layer. It can also be.
According to this configuration, the abundance of the substrate and the second dielectric layer disposed around the fine metal wire can be changed, and a design suitable for the required optical characteristics is possible.

In the present invention, the interval between the two fine metal wires adjacent to each other with the second dielectric layer interposed therebetween is equal to the interval between the two adjacent metal fine wires without sandwiching the second dielectric layer. can do.
In the present invention, an interval between the two fine metal wires adjacent to each other with the second dielectric layer interposed therebetween is different from an interval between the two fine metal wires adjacent to each other without sandwiching the second dielectric layer. It can also be.
According to this structure, the freedom degree of the space | interval of a metal fine wire becomes high, and the design of the metal fine wire suitable for the required optical characteristic becomes easy.

  Further, in the method for manufacturing a polarizing element of the present invention, the step of forming a metal film on the substrate so as to cover the upper surfaces and side surfaces of the plurality of temporary protrusions provided in a substantially striped shape in plan view on one surface side of the substrate. And removing the metal film that is a part of the metal film and is provided on the upper surface of the temporary ridge portion and a region between the adjacent temporary ridge portions, and on both sides of the temporary ridge portion. The method includes a step of forming a plurality of fine metal wires, and a step of digging up the temporary protrusions and the substrate exposed from a region where a part of the metal film is removed.

  According to this method, the fine metal wires can be provided with a cycle that is half the cycle (pitch) of the ridges, and it is easy to narrow the pitch of the fine metal wires. In addition, after forming the temporary ridges in advance, forming the fine metal wires, and then dug down the temporary ridges and the grooves, thereby reducing the substrate material disposed around the fine metal wires and having a high aspect ratio. Formation of a fine metal wire can be easily achieved. Therefore, a polarizing element having good optical characteristics can be easily formed.

In the present invention, it is desirable to dig up the temporary protrusion and the substrate simultaneously.
According to this method, a manufacturing process can be simplified and manufacture becomes easy.

The projection display device of the present invention includes an illumination optical system that emits light, a liquid crystal light valve that modulates the light, the polarizing element that receives light modulated by the liquid crystal light valve, and the polarizing element. And a projection optical system that projects the transmitted polarized light onto the projection surface.
According to this configuration, since the polarizing element having excellent optical characteristics is provided, it is possible to provide a projection display apparatus having high reliability and excellent display characteristics.

In the present invention, the illumination optical system emits light including a plurality of colored lights having different wavelengths, the liquid crystal light valve is provided corresponding to each of the plurality of colored lights, and the polarizing element is the polarized light It is desirable that the depth of digging in the groove provided between the plurality of fine metal wires of the element be different corresponding to the color light modulated by the liquid crystal light valve.
According to this configuration, since a polarizing element designed for a plurality of color lights is used, a transmittance can be controlled for each color light, and a projection display device capable of excellent display can be obtained.

The liquid crystal device of the present invention is characterized in that a liquid crystal layer is sandwiched between a pair of substrates, and the above-described polarizing element is formed on the liquid crystal layer side of at least one of the pair of substrates. .
According to this configuration, it is possible to provide a liquid crystal device having a polarizing element having excellent optical characteristics and having excellent display characteristics.

An electronic apparatus according to the present invention includes the above-described liquid crystal device.
According to this configuration, it is possible to provide an electronic apparatus including a display unit or a light modulation unit that is excellent in display quality and reliability.

It is the schematic of the polarizing element which concerns on embodiment of this invention. It is process sectional drawing which shows the manufacturing process of the polarizing element of this embodiment. It is a schematic block diagram which shows an example of the exposure apparatus used for manufacture of a polarizing element. It is a schematic diagram of a projector which is one form of electronic equipment. It is a schematic block diagram which shows an example of the liquid crystal device provided with the polarizing element of this embodiment. It is a perspective view of a mobile phone which is one form of electronic equipment. It is explanatory drawing which shows the Example of this invention. It is explanatory drawing which shows the Example of this invention. It is explanatory drawing which shows the Example of this invention. It is explanatory drawing which shows the Example of this invention. It is explanatory drawing which shows the Example of this invention. It is explanatory drawing which shows the Example of this invention. It is explanatory drawing which shows the Example of this invention. It is explanatory drawing which shows the Example of this invention.

  Hereinafter, a polarizing element and a method for manufacturing the polarizing element according to embodiments of the present invention will be described with reference to the drawings. 1A and 1B are schematic views of a polarizing element 1 according to the present embodiment. FIG. 1A is a partial perspective view, and FIG. 1B is a partial cross-sectional view of the polarizing element 1 cut along a YZ plane.

  In the following description, an XYZ coordinate system is set, and the positional relationship of each member will be described with reference to this XYZ coordinate system. At this time, a predetermined direction in the horizontal plane is defined as an X-axis direction, a direction orthogonal to the X-axis direction in the horizontal plane is defined as a Y-axis direction, and a direction orthogonal to each of the X-axis direction and the Y-axis direction is defined as a Z-axis direction. In the case of this embodiment, the extending direction of the fine metal wires is the X-axis direction, and the arrangement axis of the fine metal wires is the Y-axis direction. In all of the following drawings, the film thicknesses and dimensional ratios of the constituent elements are appropriately changed in order to make the drawings easy to see.

(Polarizing element)
As shown in FIG. 1A, the polarizing element 1 includes a substrate 11 and a fine metal wire 14 formed on the substrate 11 so as to extend in one direction.

The substrate 11 is made of a translucent dielectric material such as glass, quartz, or plastic. Depending on the application to which the polarizing element 1 is applied, since the polarizing element 1 stores heat and becomes high temperature, the substrate 11 is preferably made of glass or quartz having high heat resistance. In the present embodiment, a glass substrate mainly composed of SiO ₂ is used as the substrate 11.

  A plurality of first groove portions (groove portions) 12 extending in the X-axis direction are formed on the surface of the substrate 11, and a portion between adjacent first groove portions 12 is a ridge extending in the X-axis direction. It becomes part 13. The first groove parts 12 are formed at equal intervals in the Y-axis direction with a period shorter than the wavelength of visible light, and the ridges 13 are also arranged with the same period.

  The ridge 13 is a first ridge (first dielectric layer) 13 a having a substantially rectangular cross-sectional shape formed so as to rise from the bottom of the first groove 12 in the vertical direction (Z-axis direction) of the substrate 11. And a second ridge (second dielectric layer) 13b having a substantially rectangular cross-sectional shape formed on the upper portion of the first ridge 13a. The bottom area (plan view area from the Z-axis direction) of the second ridge 13b is smaller than the surface area of the upper surface of the first ridge 13a, and the first ridge 13a and the second ridge 13b is provided so as to overlap each other in the center in the longitudinal direction. Therefore, a part of the 1st protruding item | line part 13a is exposed on both sides on both sides of the 2nd protruding item | line part 13b. In the drawing, the exposed surface of the first ridge 13a is represented by reference numeral 13y.

  Further, the side surface of the ridge 13 facing the first groove 12, that is, the side of the first ridge 13 a comes into contact with the air in the first groove 12.

  The fine metal wires 14 are attached to the side surfaces of the second ridges 13b in each of the two exposed surfaces 13y of the ridges 13 so as to form a pair. Therefore, the side surfaces of the first ridges 13a are It is a side wall portion of one groove portion 12. Further, the fine metal wires 14 are formed so as to extend in the X-axis direction in the same manner as the extending direction of the ridges 13. Such a thin metal wire 14 transmits linearly polarized light (TM light) that vibrates in a direction (Y-axis direction) orthogonal to its extending direction, and linearly polarized light that vibrates in its own extending direction (X-axis direction). (TE light) is reflected. As a material for forming the metal thin wire 14, for example, a metal material such as aluminum is used.

  A space between two thin metal wires 14 provided on one protruding line portion 13 is a second groove portion 15 extending in the X-axis direction. Accordingly, the first groove portions 12 and the second groove portions 15 are alternately provided between the plurality of fine metal wires 14 included in the polarizing element 1. In other words, between the fine metal wires 14, the first groove portions 12 and the second convex stripe portions 13 b are alternately provided in a direction intersecting with the extending direction of the fine metal wires 14. Similar to the first groove 12, the second groove 15 is formed at equal intervals in the Y-axis direction with a period shorter than the wavelength of visible light.

  The dimension of each part shown in FIG.1 (b) is the space | interval P2 of two metal fine wires 14 provided on the protruding item | line part 13, for example, 70 nm, and the space | interval P2 of the adjacent metal fine wires 14 on both sides of the 2nd groove part 15: It is 70 nm, and the interval (period) T: 140 nm between the adjacent ridges 13. The metal thin wire 14 has a height H: 50 nm and a width W1: 17.5 nm.

  Further, the lower end 14a of the fine metal wire 14 is provided so as to be higher than the bottom 12x of the first groove 12 (on the opposite side to the substrate 11 side in the Z-axis direction). Further, the upper end 14 b of the fine metal wire 14 is provided so as to be higher than the bottom of the second groove 15, that is, the upper end 13 x of the ridge 13.

  The height L2 of the first ridge portion 13a, the height L3 of the second ridge portion 13b, and the depth L4 of the second groove portion 15 shown in the figure are the formation of the first groove portion 12 and the second groove portion 15 depending on the design. It can be controlled in the process. As is apparent from the figure, the height from the bottom 12x of the first groove 12 to the lower end 14a of the thin metal wire 14 is equal to the height L2 of the first protruding portion 13a, and the metal from the upper end 13x of the protruding portion 13 is metal. The height of the thin wire 14 to the upper end 14b is equal to the depth L4 of the second groove 15. In this embodiment, L2, L3, and L4 are all 25 nm. Further, the thickness L1 of the substrate 11 shown in the figure is the thickness from the back surface of the substrate 11.

  Among these values, the height L2 of the first ridge 13a and the depth L4 of the second groove 15 are particularly closely related to the optical characteristics of the polarizing element 1. Details will be described later with reference to examples.

(Polarizing element manufacturing method)
FIG. 2 is an explanatory diagram of a method for manufacturing the polarizing element 1. FIG. 2 corresponds to the cross-sectional view of FIG.

  First, as shown in FIG. 2A, a substrate material 11X such as a glass substrate is prepared, a resist material is applied on one surface side of the substrate material 11X by spin coating, and a resist layer is formed by pre-baking this. . As the resist material, for example, a chemically amplified positive photoresist TDUR-P338EM (manufactured by Tokyo Ohka Kogyo Co., Ltd.) is used. Then, for example, the resist layer is exposed by a two-beam interference exposure method using laser light having a wavelength of 266 nm as exposure light, and the resist layer is baked (PEB), and then the resist layer is developed. Thereby, the resist 20 having a striped pattern is formed. The height of the resist 20 of this embodiment is 200 nm.

  Here, as an exposure apparatus that performs the two-beam interference exposure method, for example, the one shown in FIG. 3 can be used. The exposure apparatus 120 includes a laser light source 121 that irradiates exposure light, a diffraction beam splitter 122, a light shielding plate 123, beam expanders 124 and 125, mirrors 126 and 127, and a stage 128 on which the substrate 11X is placed. I have.

  The laser light source 121 is, for example, an Nd: YVO4 laser device having a fourth harmonic wavelength of 266 nm. The diffractive beam splitter 122 is a branching unit that splits one laser beam output from the laser light source 121 to generate two laser beams. The diffractive beam splitter 122 is configured to generate two diffracted beams (± first order) having the same intensity when the incident laser beam is TE polarized light. Note that although it is slight, a straight component (0th-order light) is generated, which adversely affects the resist pattern. Therefore, the 0th-order light is shielded by the light shielding plate 123.

  The beam expander 124 includes a lens 124a and a spatial filter 124b, and has a configuration in which one of the two laser beams branched by the diffractive beam splitter 122 is expanded to, for example, about 300 mm. Similarly, the beam expander 125 also includes a lens 125a and a spatial filter 125b, and is configured to increase the other beam diameter of the two laser beams.

  The mirrors 126 and 127 are configured to reflect the laser beams transmitted through the beam expanders 124 and 125 toward the stage 128, respectively. Here, the mirrors 126 and 127 generate interference light by intersecting the reflected laser beams, and irradiate the resist layer 20a on the substrate 11 with the interference light.

  By irradiating the resist layer 20 a with interference light using such an exposure apparatus 120, the resist layer 20 a can be exposed with a formation pitch narrower than the wavelength of the laser light source 121.

Next, as shown in FIG. 2B, a dry etching process is performed through the resist 20, and the substrate material 11X is patterned by digging down the substrate material 11X, so that the substrate having the groove 12A and the temporary protruding portion 13A is obtained. 11A is formed. As the dry etching in this step, for example, anisotropic etching by performing reactive ion etching using a mixed gas of C ₂ F ₆ , CF ₄ , and CHF ₃ as an etching gas is preferably used.

  Next, as shown in FIG. 2C, a metal thin film 14A using aluminum as a forming material is formed on the entire surface of the substrate 11A so as to cover the upper surface and side surfaces of the temporary protrusion 13A and the bottom surface of the groove 12A. The metal thin film 14A can be formed using a generally known method such as a sputtering method, a CVD method, or a vapor deposition method.

  Next, as shown in FIG. 2 (d), among the metal thin film 14A provided on the entire surface of the substrate 11A, one of the metal thin films 14A provided on the upper surface of the temporary protrusion 13A and the bottom surface of the groove 12A. The portion is removed by dry etching to form a fine metal wire 14. For example, when anisotropic etching by reactive ion etching using a chlorine-based gas as an etching gas is performed, the width in the Y-axis direction of the formed thin metal wire 14 is preferable.

  The width and height of the thin metal wire 14 formed in this way are defined by the film thickness of the metal thin film 14A formed on the temporary protrusion 13A and the height of the temporary protrusion 13A. . Therefore, the aspect ratio of the thin metal wire 14 can be easily changed by changing the height of the temporary protruding portion 13A or the thickness of the metal thin film 14A.

Next, as shown in FIG. 2E, the first groove portion 12, the ridge portion 13, and the second groove portion 15 are formed by digging up the substrate 11A by performing dry etching using the fine metal wires 14 as a mask. To do. In the present embodiment, control is performed so that the digging amount (height of the first ridge 13a) L2 of the first groove 12 and the depth L4 of the second groove 15 are equal. The amount of digging down can be controlled by the etching time.
As described above, the polarizing element 1 of the present embodiment is completed.

  According to the polarizing element 1 having the above-described configuration, since the fine metal wires 14 are supported by the ridges 13, the fine metal wires 14 are unlikely to fall down, and damage can be suppressed. Moreover, since the substrate material between the thin metal wires 14 is removed by providing the first groove portion 12 and the second groove portion 15, it is possible to improve characteristics with respect to transmitted light. In addition, since the first groove portion 12 is dug deeper than the lower end of the thin metal wire 14 (on the substrate 11 side in the Z-axis direction), the substrate material disposed around the fine metal wire 14 can be further reduced. The characteristic with respect to transmitted light can be improved. Therefore, it can be set as the polarizing element 1 which has a favorable optical characteristic.

  Moreover, according to the manufacturing method of the polarizing element 1 having the above-described configuration, the metal fine wires 14 can be provided with a period that is half the period (pitch) of the temporary protrusion 13A that is formed in advance. Can be improved. Moreover, after forming the temporary protrusion 13A, the fine metal wire 14 is formed, and then the first groove portion 12 and the second groove portion 15 are provided, whereby the fine metal wire between the first groove portion 12 and the second groove portion can be easily formed. 14 The amount of digging from the upper end (the side opposite to the substrate 11 in the Z-axis direction) can be changed. Therefore, it is possible to easily achieve both the removal of the substrate material around the fine metal wires 14 and the suppression of the damage of the fine metal wires 14. Therefore, the polarizing element 1 having good optical characteristics can be easily formed.

  In the present embodiment, the thin metal wires 14 are formed of aluminum. However, the present invention is not limited to this, and a different metal material may be used.

  In the present embodiment, the two-beam interference exposure method is used for forming the resist 20, but the resist 20 can also be formed by transferring a resist pattern to a resist material using a nanoimprint method.

  Further, in the present embodiment, anisotropic etching is performed to form the first groove 12, and the first groove 12 having a substantially rectangular shape in cross section is shown in FIG. 1, but the lower end 14 a of the thin metal wire 14 is shown. If the bottom part 12x of the 1st groove part 12 is formed low, it will not restrict to this. For example, the first ridge 13 a that is the side wall of the first groove 12 may be over-etched, and the first groove 12 may enter the region overlapping with the fine metal wire 14.

  Moreover, in this embodiment, although the space | interval P1 of the two metal fine wires 14 provided on the protruding item | line part 13 and the space | interval P2 of the adjacent metal fine wires 14 on both sides of the 2nd groove part 15 shall be equal. Not limited to this, the interval P1 and the interval P2 may be different. Also, some of the intervals P1 may be different from the other intervals P1, and some of the intervals P2 may be different from the other intervals P2.

  In the present embodiment, the height L2 of the first ridge 13a and the depth L4 of the second groove 15 are formed to be equal, but not limited to this, the values of L2 and L4 are It may be different. As will be described later with reference to examples, it was found that a polarizing element having different values of L2 and L4 can provide good optical characteristics. Suitable for obtaining.

  For example, by performing dry etching in FIG. 2E through an appropriate mask, the depth of the first groove 12 and the second groove 15 can be changed.

  Further, by using different formation materials for the ridges 13 and the substrate 11 below the ridges 13, the difference between the etching rates due to the difference in the formation materials can be used, and the first groove 12 It is also possible to change the digging depth with the second groove 15. Such a configuration can be achieved by forming a layer of the material for forming the ridges 13 on the surface of the substrate material 11X.

  Further, even when the interval P1 and the interval P2 are set to different values, the manner in which the etching gas enters can be changed and the etching rate can be made different for each groove portion, so that the depth of the first groove portion 12 and the second groove portion 15 is reduced. Can be changed.

[Projection display]
Next, an embodiment of the electronic device of the present invention will be described. 4 includes a light source 810, dichroic mirrors 813 and 814, reflection mirrors 815, 816, and 817, an incident lens 818, a relay lens 819, an exit lens 820, light modulation units 822, 823, and 824, and a cross dichroic prism 825. , And a projection lens 826.

  The light source 810 includes a lamp 811 such as a metal halide and a reflector 812 that reflects the light of the lamp. As the light source 810, besides a metal halide, an ultrahigh pressure mercury lamp, a flash mercury lamp, a high pressure mercury lamp, a deep UV lamp, a xenon lamp, a xenon flash lamp, or the like can be used.

  The dichroic mirror 813 transmits red light contained in white light from the light source 810 and reflects blue light and green light. The transmitted red light is reflected by the reflection mirror 817 and is incident on the light modulation unit 822 for red light. Of the blue light and green light reflected by the dichroic mirror 813, green light is reflected by the dichroic mirror 814 and is incident on the green light light modulation unit 823. The blue light is transmitted through the dichroic mirror 814, and the blue light is transmitted through the relay optical system 821 including the incident lens 818, the relay lens 819, and the output lens 820 provided to prevent light loss due to a long optical path. Is incident on.

  In the light modulators 822 to 824, an incident side polarization element 840 and an emission side polarization element part 850 are arranged on both sides of the liquid crystal light valve 830. The incident side polarizing element 840 and the exit side polarizing element unit 850 are arranged so that their transmission axes are orthogonal to each other (crossed Nicols arrangement).

  The incident side polarization element 840 is a reflection type polarization element, and reflects light in a vibration direction orthogonal to the transmission axis.

  On the other hand, the exit-side polarizing element unit 850 includes a first polarizing element (pre-polarizing plate, pre-polarizer) 852 and a second polarizing element 854. As the first polarizing element 852, the polarizing element of the present invention according to the second embodiment described above, which includes a protective film and has high heat resistance, is used. The second polarizing element 854 is a polarizing element using an organic material as a forming material. The exit side polarization element section 850 is an absorption type polarization element, and the polarization elements 852 and 854 cooperate to absorb light. The first polarizing element 852 may be the polarizing element according to the first embodiment of the present invention.

  In general, an absorption-type polarizing element formed of an organic material is easily deteriorated by heat, so that it is difficult to use it as a polarizing means for a high-power projector that requires high luminance. However, in the projector 800 of the present invention, the first polarizing element 852 formed of an inorganic material having high heat resistance is disposed between the second polarizing element 854 and the liquid crystal light valve 830, and the polarizing elements 852 and 854 are disposed. Cooperate to absorb light. Therefore, deterioration of the second polarizing element 854 formed of an organic material can be suppressed.

  In addition, each first polarizing element 852 has the first polarizing element 852 corresponding to the wavelength of the light modulated by the light modulating units 822 to 824 in order to efficiently transmit the light modulated by the light modulating units 822 to 824. The digging depth between the fine metal wires is changed. Therefore, efficient light utilization is possible.

  The three color lights modulated by the respective light modulation units 822 to 824 are incident on the cross dichroic prism 825. The cross dichroic prism 825 is formed by bonding four right-angle prisms. A dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in an X shape at the interface. Yes. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 827 by the projection lens 826 which is a projection optical system, and the image is enlarged and displayed.

  Since the projector 800 configured as described above uses the above-described polarizing element of the present invention for the exit-side polarizing element unit 850, deterioration of the polarizing element can be suppressed even when a high-output light source is used. Therefore, the projector 800 having high reliability and excellent display characteristics can be obtained.

[Liquid Crystal Device]
FIG. 5 is a schematic cross-sectional view showing an example of a liquid crystal device 300 including the polarizing element according to the present invention. The liquid crystal device 300 of the present embodiment is configured such that a liquid crystal layer 350 is sandwiched between an element substrate 210 and a counter substrate 320.

  The element substrate 210 and the counter substrate 320 include polarizing elements 330 and 340. The polarizing elements 330 and 340 are the polarizing elements of the second embodiment described above, and each has a structure in which a thin metal wire having a protective film is formed on a light-transmitting substrate such as glass, quartz, or plastic. Yes.

  The polarizing element 330 includes a substrate body 331, a metal thin wire 332, and a protective film 333, and the polarizing element 340 includes a substrate body 341, a metal thin wire 242, and a protective film 343, respectively. In the present embodiment, the substrate bodies 331 and 341 are not only substrates for polarizing elements but also serve as substrates for liquid crystal devices. Further, the fine metal wire 332 and the fine metal wire 242 are arranged so as to cross each other. In any of the polarizing elements, the fine metal wire is disposed on the inner surface side (the liquid crystal layer 350 side).

  On the inner surface side of the polarizing element 330, a pixel electrode 314, wiring (not shown) and a TFT element are provided, and an alignment film 316 is provided. Similarly, a common electrode 324 and an alignment film 326 are provided on the inner surface side of the polarizing element 340.

  In the liquid crystal device having such a configuration, the substrate main bodies 331 and 341 function as the substrate for the liquid crystal device and the substrate for the polarizing element, so that the number of components can be reduced. Therefore, the entire device can be thinned, and the function of the liquid crystal device 300 can be improved. Furthermore, since the device structure is simplified, manufacturing is easy and cost reduction can be achieved.

  In the liquid crystal device of the present embodiment, the polarizing element of the second embodiment is used, but the polarizing element of the first embodiment that does not include a protective film can also be used. In that case, it is preferable to provide a protective layer for protecting each polarizing element separately at the positions of the protective films 333 and 343.

[Electronics]
Next, another embodiment according to the electronic apparatus of the present invention will be described. 6 is a perspective view illustrating an example of an electronic apparatus using the liquid crystal device illustrated in FIG. A cellular phone (electronic device) 1300 illustrated in FIG. 6 includes the liquid crystal device of the present invention as a small-sized display portion 1301, and includes a plurality of operation buttons 1302, an earpiece 1303, and a mouthpiece 1304. . Accordingly, the mobile phone 1300 including a display portion that is excellent in reliability and capable of high-quality display can be provided.

  In addition to the mobile phone, the liquid crystal device of the present invention includes an electronic book, a personal computer, a digital still camera, a liquid crystal television, a projector, a viewfinder type or a monitor direct view type video tape recorder, a car navigation device, a pager, It can be suitably used as image display means for electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, devices equipped with touch panels, and the like.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

[Example]
Examples of the present invention will be described below. In this example, evaluation was performed by simulation analysis in order to confirm the effects of the invention. In this example, evaluation was performed by simulation analysis of the modeled polarizing element. In the following description of the embodiments, the reference numerals shown in FIG. 1 are used as appropriate.

  The simulation analysis was performed using GSolver, which is analysis software manufactured by Grating Solver Development, using each parameter such as the shape and refractive index of the modeled polarizing element.

[Verification of the depth of the first groove]
First, with respect to the depth of the first groove 12, a polarizing element dug down until the bottom 12 x of the first groove 12 is located below the lower end 14 a of the thin metal wire 14 (hereinafter, this structure is referred to as a structure A), The optical characteristics of the polarizing element (hereinafter, this structure is referred to as structure B) in which the bottom 12x of the first groove 12 is the same height as the lower end 14a of the thin metal wire 14 are compared, and the depth of the first groove 12 is deepened. The influence on the optical characteristics of the polarizing element was verified. The optical characteristics compared are light transmittance (Tp) for TM light, light transmittance (Tc) for TE light, reflectance (Rp) for TM light, and reflectance (Rc) for TE light.

  Here, in the structure shown in FIG. 1B, a model in which the height H of the fine metal wire is constant and the values of L2 and L4 are changed by the same amount is verified for the structure A. Similarly, for structure B, L2 was set to 0, and a model in which the value of L4 was changed was verified. In any structure, the value of L3 changes complementarily according to the change of L4.

  7 and 8 are graphs showing the evaluation results. Each (a) shows transmission characteristics with the horizontal axis representing the values L2 and L4 (nm) and the vertical axis representing the transmittance (%). Each (b) represents the horizontal axis representing the values L2 and L4 (nm) and the vertical axis. The reflection characteristics with the axis as the reflectance (%) are shown. FIG. 7 shows the result when the distance between the metal thin wires (the interval (period) between adjacent ridges 13) T is 70 nm, and FIG. 8 shows the result when the period T is 140 nm.

  As a result of the evaluation, a comparison between FIG. 7 and FIG. 8 showed better optical characteristics when the period T was 70 nm than when the period T was 140 nm, and it was confirmed that the physical properties were improved by narrowing the fine metal wires. . Further, when the results of the structure A and the structure B were compared, the polarizing element of the structure A showed better physical properties regardless of the period of the thin metal wire.

[Verification of digging depth between first groove and second groove]
Next, with respect to the polarizing element of structure A, a model in which the values of L2 and L4 were made different was verified.

  9 to 14 are graphs showing the evaluation results. 9 to 11 show the results when the period T is 70 nm, and FIGS. 12 to 14 show the results when the period T is 140 nm. 9 and 12 are the evaluation results for blue light (wavelength: 440 nm), FIGS. 10 and 13 are the evaluation results for green light (wavelength: 530 nm), and FIGS. 11 and 14 are for red light (wavelength: 640 nm). The evaluation results are shown.

  Each (a) shows transmission characteristics with the horizontal axis representing the L2 value (nm) and the vertical axis representing the transmittance (%), and the optical characteristics with respect to changes in the L2 value when the L4 value is used as a reference. It shows a change. Each (b) also shows reflection characteristics with the horizontal axis representing the value of L2 (nm) and the vertical axis representing the reflectance (%).

  As a result of the evaluation, the light of each color showed the best Tp in the structure having different values of L2 and L4. The optimum value of L2 with respect to a predetermined value of L4 in each color light is as shown in Table 1 below.

  From this result, it was found that the optimum values of L2 and L4 differ depending on the transmission wavelength. Further, it has been found that the values of L2 and L4 do not necessarily have to be equal, but rather the larger the value of L2, the better the transmittance.

  From these results, it was confirmed that the polarizing element having the configuration of the present invention has good optical characteristics, and it was confirmed that the configuration of the present invention is effective for solving the problems.

DESCRIPTION OF SYMBOLS 1,330,340 ... Polarizing element, 11 ... Board | substrate, 11X ... Board | substrate material, 12 ... 1st groove part (groove part), 13 ... Projection stripe part, 13a ... 1st projection stripe part (1st dielectric material layer), 13b ... Second ridge (second dielectric layer), 13A ... Temporary ridge, 14 ... Metal fine wire, 20 ... Resist, 300 ... Liquid crystal device, 310 ... Element substrate (pair of substrates), 320 ... Counter substrate (pair) ) ... Light source (illumination optical system), 826 ... Projection lens (projection optical system), 830 ... Liquid crystal light valve, 852 ... First polarizing element (Polarizing element), 1300 ... mobile phone (electronic device),

Claims (11)

A substrate,
A plurality of first dielectric layers provided in a substantially stripe shape in plan view on the substrate;
On each of the first dielectric layers, a pair of fine metal wires provided extending in a substantially stripe shape in plan view in the same direction as the extending direction of the first dielectric layer;
And a second dielectric layer provided on each of the first dielectric layers and buried in a region between the pair of thin metal wires lower than the upper end of the fine metal wires. Polarizing element.   The height from the upper end of the thin metal wire to the upper end of the second dielectric layer is equal to the height from the lower end of the thin metal wire to the bottom of the region between the first dielectric layers. A polarizing element according to 1.   The height from the lower end of the thin metal wire to the bottom of the region between the first dielectric layers is larger than the height from the upper end of the thin metal wire to the upper end of the second dielectric layer. The polarizing element according to 1.   The interval between the two fine metal wires adjacent to each other with the second dielectric layer interposed therebetween is equal to the interval between the two fine metal wires adjacent to each other without sandwiching the second dielectric layer. The polarizing element according to any one of 1 to 3.   The interval between the two fine metal wires adjacent to each other with the second dielectric layer interposed therebetween is different from the interval between the two fine metal wires adjacent to each other without sandwiching the second dielectric layer. The polarizing element according to any one of 1 to 3. Covering a top surface and side surfaces of a plurality of temporary protrusions provided in a substantially striped shape in plan view on one surface side of the substrate, and forming a metal film on the substrate;
A part of the metal film, the metal film provided on the upper surface of the temporary ridge portion and a region between the adjacent temporary ridge portions is removed, and a plurality of pieces are provided on both sides of the temporary ridge portion. Forming a thin metal wire;
And a step of digging up the temporary protrusions and the substrate exposed from a region where a part of the metal film has been removed.   The method for manufacturing a polarizing element according to claim 6, wherein the temporary protrusions and the substrate are simultaneously dug down. An illumination optical system that emits light;
A liquid crystal light valve that modulates the light;
The polarizing element according to any one of claims 1 to 5, wherein light modulated by the liquid crystal light valve enters.
A projection display system, comprising: a projection optical system that projects the polarized light transmitted through the polarizing element onto a projection surface. The illumination optical system emits light including a plurality of colored lights having different wavelengths,
The liquid crystal light valve is provided corresponding to each of the plurality of color lights,
9. The polarizing element according to claim 8, wherein the depth of the groove provided between the plurality of fine metal wires of the polarizing element differs according to the color light modulated by the liquid crystal light valve. The projection display device described in 1.   A liquid crystal layer is sandwiched between a pair of substrates, and the polarizing element according to claim 1 is formed on the liquid crystal layer side of at least one of the pair of substrates. A liquid crystal device characterized by the above.   An electronic apparatus comprising the liquid crystal device according to claim 10.

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