JP4499180B1 - Substrate for liquid crystal projector, liquid crystal panel for liquid crystal projector using the same, and liquid crystal projector - Google Patents

Abstract

An object of the present invention is to provide a substrate for a liquid crystal projector that is excellent in the transmittance of light of each wavelength of R (red), G (green), and B (blue), the fluctuation thereof is suppressed, and the productivity is excellent.
A liquid crystal projector substrate having a substrate main body and a laminated film laminated on the substrate main body, wherein the laminated film is in order from the substrate main body 2 side. (H) and low-refractive index film 3 (L) are alternately laminated in a total of six layers, and a film thickness of the laminated film 3 is not less than 155 nm and not more than 250 nm.
[Selection] Figure 1

Description

  The present invention relates to a liquid crystal projector substrate, a liquid crystal projector liquid crystal panel using the same, and a liquid crystal projector.

  Conventionally, a liquid crystal projector is used to project image information onto a projection object such as a screen. Such a liquid crystal projector has a liquid crystal panel as a spatial modulation element, modulates the liquid crystal panel by irradiating light from a light source, and projects it onto an external projection object by a projection lens.

  In a liquid crystal panel, liquid crystal is arranged between a pair of substrates, a display electrode for aligning liquid crystals is formed by applying a voltage to one substrate, and a common electrode is formed on the other substrate (counter substrate). An ITO (Indium Tin Oxide) film is formed on the entire surface.

  As the counter substrate, for example, a glass substrate or the like is used as the substrate body, a light shielding member called a black matrix is formed on the substrate body, and an ITO film is formed on substantially the entire surface so as to cover the light shielding member. Are known (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 8-338991

  In recent years, with regard to such a liquid crystal projector, in order to improve brightness, improve the performance as a projector, reduce power consumption, and consider the environment, the transmittance of the liquid crystal panel, particularly the counter substrate, has been increased. There is a need to improve.

  However, such a counter substrate is not suitable for use as a projector if it only has excellent transmittance of light of a specific wavelength, and transmits light of each wavelength of R (red), G (green), and B (blue). It is required to be excellent in rate. Further, even though the transmittance of light of each wavelength is excellent, if there is a large difference in the transmittance, it is not suitable for use as a projector, and the variation in transmittance is required to be small. Furthermore, from the viewpoint of mass productivity, it is also required that there is no excessive increase in the manufacturing process.

  The present invention has been made in order to solve the above-described problems, and provides a liquid crystal projector substrate that has excellent transmittance of light of each wavelength of R, G, and B, little variation, and excellent productivity. It is intended to provide. Another object of the present invention is to provide a liquid crystal panel for a liquid crystal projector and a liquid crystal projector using such a substrate for a liquid crystal projector.

The substrate for a liquid crystal projector of the present invention comprises a substrate body, a laminated film laminated on the substrate body, and an ITO film provided on the surface of the laminated film opposite to the substrate body side. In the laminated film, a high refractive index film having a refractive index of 1.9 to 2.5 and a low refractive index film having a refractive index of 1.2 to 1.5 are alternately arranged in this order from the substrate body side. A total of 6 layers are laminated in each of 3 layers, and the film thickness of the laminated film is 155 nm or more and 250 nm or less , and the film thickness of the refractive index film that is the first layer from the substrate body side in the laminated film is 5 nm or more and 25 nm. Hereinafter, the film thickness of the second refractive index film is 15 nm or more and 75 nm or less, and the film thickness of the third refractive index film is 5 nm or more and 45 nm or less. The film thickness of the fourth refractive index film is 5 nm or more. 35 nm or less The thickness of the fifth refractive index film is 25 nm or less 135nm or less, the film thickness of the refractive-index film serving as the 6 th layer is at 40nm or more 55nm or less, the wavelength is 450 nm, 550 nm, and 650nm light transmittance is equal to or 92% or more

  The high refractive index film is preferably made of at least one selected from tantalum oxide, titanium oxide, zirconium oxide, and hafnium oxide, and the low refractive index film is made of silicon oxide and magnesium fluoride. It is preferable that it consists of at least 1 sort chosen from these.

  The surface of the laminated film on the opposite side to the substrate body side of the refractive index film that is the sixth layer from the substrate body side preferably has a surface roughness of 0.5 nm or less.

  In the laminated film, the total thickness of the two layers of the refractive index film as the second layer and the refractive index film as the fifth layer from the substrate body side is preferably 60 nm or more and 165 nm or less.

  The total film thickness of a total of three high refractive index films, which are odd layers from the substrate body side in the laminated film, is preferably 60 nm or more and 155 nm or less, and the even layer from the substrate body side in the laminated film. The total thickness of the three low refractive index films is preferably 80 nm or more and 155 nm or less.

The film thickness of the pre-Symbol ITO film is preferably 10nm or more 30nm or less. The liquid crystal projector substrate preferably has a variation value represented by a difference between a maximum value and a minimum value of light transmittance in a wavelength range of 400 nm to 700 nm of 4% or less. The substrate body is preferably a quartz substrate, for example.

  A liquid crystal panel for a liquid crystal projector of the present invention is a liquid crystal panel for a liquid crystal projector having a pair of substrates disposed opposite to each other and a liquid crystal disposed between the pair of substrates, and one of the substrates is as described above. It is a substrate for a liquid crystal projector of the present invention.

  The liquid crystal projector of the present invention is a liquid crystal projector having a liquid crystal panel for forming image information to be projected onto a projection object, and the liquid crystal panel is the liquid crystal panel for a liquid crystal projector of the present invention described above. Features.

  According to the present invention, there is provided a liquid crystal projector substrate that is excellent in the transmittance of light of each wavelength of R, G, and B, has little fluctuation, is excellent in productivity, and is suitably used for a liquid crystal panel of a liquid crystal projector. be able to.

  In addition, according to the present invention, it has such a substrate for a liquid crystal projector, is excellent in the transmittance of light of each wavelength of R, G, and B, has little fluctuation, is excellent in productivity, and is suitable for a liquid crystal projector. A liquid crystal panel for a liquid crystal projector used in the above can be provided.

  Furthermore, according to the present invention, there is provided a liquid crystal projector that has such a liquid crystal panel for a liquid crystal projector, has improved brightness, improved performance as a projector, reduced power consumption, and is environmentally friendly. can do.

Sectional drawing which shows an example of the board | substrate for liquid crystal projectors of this invention. Sectional drawing which shows an example of the board | substrate for liquid crystal projectors of this invention which has an ITO film | membrane and a light-shielding member. Sectional drawing which shows the other example of the board | substrate for liquid crystal projectors of this invention which has an ITO film | membrane and a light-shielding member. Sectional drawing which shows an example of the liquid crystal panel for liquid crystal projectors of this invention. 6 is a graph showing the transmittance of the liquid crystal projector substrate of Example 1 and Comparative Example 1. 10 is a graph showing the transmittance of a liquid crystal projector substrate of Comparative Examples 2 and 3; 6 is a graph showing the transmittance of the liquid crystal projector substrates of Examples 2 and 3. FIG. 7 is a graph showing the transmittance of the liquid crystal projector substrates of Examples 4 and 5.

  The present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing an example of a substrate for a liquid crystal projector of the present invention.
The liquid crystal projector substrate 1 of the present invention aligns liquid crystal by applying a voltage among a pair of substrates arranged via liquid crystal in a liquid crystal panel for liquid crystal projector (hereinafter simply referred to as a liquid crystal panel) as described later. The substrate (opposite substrate) is arranged so as to face the substrate (main substrate) on which the display electrode is formed.

  The liquid crystal projector substrate 1 of the present invention has a substrate body 2 and a laminated film 3 laminated on one main surface of the substrate body 2. In the laminated film 3, a high refractive index film 31, a low refractive index film 32, a high refractive index film 33, a low refractive index film 34, a high refractive index film 35, and a low refractive index film 36 are laminated in order from the substrate body 2 side. A high refractive index film and a low refractive index film are alternately laminated in a total of 6 layers, for a total of 6 layers. Further, the film thickness of the laminated film 3, that is, the total film thickness of the six layers including the three high refractive index films and the three low refractive index films is 155 nm or more and 250 nm or less.

  In FIG. 1, the letter “H” in parentheses means a high refractive index film, and the letter “L” means a low refractive index film. In the following, when the three high refractive index films are not particularly distinguished, they are referred to as a high refractive index film 3 (H). Similarly, when the three low refractive index films are not particularly distinguished, the low refractive index film 3 ( L) and will be described. In addition, for example, in the case where the transmittance capable of exhibiting sufficient functions for a liquid crystal projector can be maintained, a film other than the high refractive index film and the low refractive index film, for example, between the substrate and the laminated film 3 is used. A base film or the like may be provided on the substrate, or a protective film or the like may be provided on the laminated film 3.

  In such a liquid crystal projector substrate 1, an ITO (Indium Tin Oxide) film (not shown) is formed on the main surface of the laminated film 3 opposite to the substrate body 2 side (upper side in the figure), and this ITO film is formed. The liquid crystal panel is arranged so as to face the main substrate so that the main surface side is the inner side.

  In such a liquid crystal projector substrate 1, a high refractive index film 3 (H) and a low refractive index film 3 (L) are alternately laminated on the substrate body 2 as a laminated film 3, for a total of 6 layers, When the ITO film is formed as described above by setting the film thickness to 155 nm or more and 250 nm or less, the transmittance of light of each wavelength of R, G, and B is excellent, the fluctuation is small, and the productivity And can be suitably used for a liquid crystal panel in a liquid crystal projector.

  That is, when an ITO film is directly formed on the substrate body 2 as in the prior art, for example, when the substrate body 2 is a quartz substrate, the refractive index of the quartz substrate (refractive index at a wavelength of 550 nm, the same applies hereinafter) is about 1.46. In addition, since the refractive index of the ITO film is about 2.1, sufficient transmittance cannot always be obtained due to the difference in refractive index. Further, even if the transmittance of light of any wavelength of R, G, and B can be improved, the transmittance of light of each wavelength cannot always be made sufficient, and the fluctuation thereof is small. Can not do it.

  As described above, by forming the laminated film 3 having a specific laminated structure and film thickness on the substrate body 2, the difference in refractive index between the substrate body 2 and the ITO film is alleviated and the transmittance is excellent. In particular, the transmittance of light of each wavelength of R, G, and B is excellent, the fluctuation thereof is small, and the balance is excellent. In addition, the laminated film 3 having such a laminated structure and film thickness does not necessarily add a large manufacturing process as compared with the conventional liquid crystal projector substrate, and therefore the productivity may be sufficient. it can.

  Here, when the number of layers of the laminated film 3 is less than 6, the transmittance of light of each wavelength of R, G, and B may not be sufficient, and the variation may not be reduced. If the number of layers of the laminated film 3 is 6 layers, the transmittance of light of each wavelength of R, G, and B can be made sufficient, and the fluctuation can be sufficiently reduced, exceeding this. On the other hand, there is a possibility that the manufacturing process increases and the productivity is lowered.

  Further, when the film thickness of the laminated film 3 is less than 155 nm, the transmittance of light of each wavelength of R, G, and B is necessarily sufficient even if the number of layers of the laminated film 3 is six. And the fluctuation cannot be reduced sufficiently. If the film thickness of the laminated film 3 is 250 nm, the transmittance of light of each wavelength of R, G, and B can be made sufficient, and the fluctuation can be sufficiently reduced. Manufacturing time may increase and productivity may be reduced. From the viewpoint of such characteristics and productivity, the film thickness of the laminated film 3 is preferably 225 nm or more and 245 nm or less, particularly preferably 230 nm or more and 240 nm or less.

  In the liquid crystal projector substrate 1 according to the present invention, by adopting such a configuration, for example, the substrate body 2 is a quartz substrate having a thickness of 0.5 mm or more and 2.5 mm or more, and the film thickness of the laminated film 3 is 10 nm or more. When an ITO film having a thickness of 30 nm or less is formed, the transmittance of light having wavelengths of 450 nm, 550 nm, and 650 nm can be 92% or more, more preferably 93% or more, and still more preferably 94% or more.

  Further, in the liquid crystal projector substrate 1 of the present invention, under the same conditions, the fluctuation value represented by the difference between the maximum value and the minimum value of the light transmittance in the wavelength range of 400 nm to 700 nm is 4% or less. More preferably, it can be 3% or less, and more preferably 2% or less. For example, when the maximum value of the transmittance of light having a wavelength in the range of 400 nm to 700 nm is 95% and the minimum value is 93%, the variation value can be obtained as 95% −93% = 2%. .

  As the substrate body 2 in the liquid crystal projector substrate 1, the above-described quartz substrate is preferably used. However, the substrate is not necessarily limited to this as long as it is made of a translucent material. Is mentioned. Further, the thickness of the substrate body 2 is not necessarily limited, and may be the same as that generally employed as the thickness of the substrate for a liquid crystal projector. A quartz substrate is preferred because of its high transmittance and low thermal expansion.

  The high refractive index film 3 (H) has, for example, a refractive index (refractive index at a wavelength of 550 nm, the same applies hereinafter) of 1.9 or more, preferably 1.9 or more and 2.5 or less. Specifically, tantalum oxide (refractive index: 2.0 to 2.2), titanium oxide (refractive index: 2.2 to 2.5), zirconium oxide (refractive index: 1.9 to 2.0) And at least one selected from high refractive index materials such as hafnium oxide (refractive index: 1.95 to 2.15). Among these, those made of tantalum oxide having excellent heat resistance are preferable from the viewpoint of suppressing deterioration due to heat treatment when forming the ITO film.

  The three high refractive index films 3 (H) may be made of the same high refractive index material, or may be made of different high refractive index materials. Further, each of the three high refractive index films 3 (H) may be a single layer film or a multilayer film. When the high refractive index film 3 (H) is a multilayer film, each layer constituting the multilayer film can be made of the above-described high refractive index material.

  On the other hand, as the low refractive index film 3 (L), for example, the refractive index is 1.5 or less, preferably 1.2 or more and 1.5 or less. Specifically, silicon oxide ( Examples thereof include those composed of at least one selected from low refractive index materials such as refractive index: 1.44 to 1.48) and magnesium fluoride (refractive index: 1.35 to 1.41).

  The three layers of the low refractive index film 3 (L) may be made of the same low refractive index material as in the case of the high refractive index film 3 (H), or may be made of different low refractive index materials. It may be. Further, each of the three high refractive index films 3 (H) may be a single layer film or a multilayer film. When the low refractive index film 3 (L) is a multilayer film, each layer constituting the multilayer film can be made of the above-described low refractive index material.

  The film thickness of the low refractive index film 32 which is the second layer from the substrate body 2 side in the laminated film 3 is preferably 15 nm or more and 75 nm or less. Moreover, it is preferable that the film thickness of the high refractive index film | membrane 35 used as the 5th layer is 25 nm or more and 135 nm or less. For the laminated film 3 in which the high refractive index film 3 (H) and the low refractive index film 3 (L) are alternately laminated in a total of six layers, a high refractive index that is the first to third layers from the substrate body 2 side. The refractive index film 31, the low refractive index film 32, and the high refractive index film 33, and the low refractive index film 34, the high refractive index film 35, and the low refractive index film 36 that are the fourth to sixth layers can be broadly classified.

  In particular, the film thickness of the second low-refractive index film 32 serving as the first to third intermediate layers and the film thickness of the fifth high-refractive index film 35 serving as the fourth to sixth intermediate layers are set. By setting it within the above range, it is possible to effectively and effectively improve the transmittance of light of each wavelength of R, G, and B, and to effectively and effectively suppress the variation thereof.

  The film thickness of the low refractive index film 32 as the second layer is more preferably 30 nm to 75 nm, and still more preferably 50 nm to 60 nm. The film thickness of the high refractive index film 35 serving as the fifth layer is more preferably 50 nm to 70 nm, and still more preferably 60 nm to 70 nm.

  The low refractive index film 32 as the second layer and the high refractive index film 35 as the fifth layer preferably have a total film thickness of 60 nm to 165 nm. If the total thickness of the two layers is out of such a range, the transmittance of light of each wavelength of R, G, and B may not be sufficient, and the variation may not be sufficiently reduced. The thickness of these two layers is more preferably 70 nm to 130 nm, and still more preferably 115 nm to 125 nm.

  The film thickness of the high refractive index film 31 as the first layer is preferably 5 nm or more and 25 nm or less. Moreover, it is preferable that the film thickness of the low refractive index film | membrane 36 used as the 6th layer is 40 nm or more and 55 nm or less. By making the film thickness of the high-refractive index film 31 as the first layer and the low-refractive index film 36 as the sixth layer like this, the transmittance of light of each wavelength of R, G, B is excellent, The fluctuations are less likely to occur. The film thickness of the high refractive index film 31 as the first layer is more preferably 5 nm or more and 15 nm or less. The film thickness of the low refractive index film 36 serving as the sixth layer is more preferably 45 nm or more and 50 nm or less.

  Further, the surface of the sixth layer of the low refractive index film 36 on the side opposite to the substrate body 2 side (upper side in the figure) has a decrease in transmittance at these interfaces when the ITO film is laminated. From the viewpoint of suppression, the surface roughness is preferably 0.5 nm or less. The surface roughness here is measured according to JIS B0601.

  The film thickness of the third layer of the high refractive index film 33 is preferably 5 nm or more and 45 nm or less. The film thickness of the low refractive index film 34 as the fourth layer is preferably 5 nm or more and 35 nm or less. By making the film thickness of the high refractive index film 33 as the third layer and the low refractive index film 34 as the fourth layer such as this, the transmittance of light of each wavelength of R, G, B is excellent. The fluctuations are less likely to occur. The film thickness of the high refractive index film 33 serving as the third layer is more preferably 20 nm or more and 45 nm or less, and further preferably 35 nm or more and 45 nm or less. The film thickness of the high refractive index film 33 as the fourth layer is more preferably 10 nm or more and 30 nm or less, and further preferably 15 nm or more and 25 nm or less.

  Further, the total thickness of the odd-numbered layers, that is, the three layers of the high refractive index film 31, the high refractive index film 33, and the high refractive index film 35, which are the high refractive index film 3 (H), is 60 nm or more and 155 nm or less. Preferably there is. The total thickness of the even-numbered layers, that is, the three layers of the low refractive index film 32, the low refractive index film 34, and the low refractive index film 36, which are the low refractive index film 3 (L), is 80 nm or more and 155 nm or less. Preferably there is. By setting the total thickness of the odd-numbered layers and even-numbered layers to such values, the transmittance of light of each wavelength of R, G, and B is excellent, and the variation is easily reduced. The total thickness of the three odd-numbered layers is more preferably 100 nm to 120 nm, and still more preferably 110 nm to 120 nm. The film thickness of the high refractive index film 33 as the fourth layer is more preferably 100 nm to 125 nm, and still more preferably 115 nm to 125 nm. The film thickness can be optimized by evaluating all films as equivalent.

  The most typical form of the substrate 1 for a liquid crystal projector is a quartz substrate having a substrate body 2 with a thickness of 1 mm or more and 1.5 mm or more, and a high refractive index film 3 (H) (high refractive index film 31, high refractive index). The film 33 and the high refractive index film 35) are made of a tantalum oxide film, and the low refractive index film 3 (L) (the low refractive index film 32, the low refractive index film 34, and the low refractive index film 36) are made of silicon oxide. The film thickness of the high refractive index film 31 is 10 nm, the film thickness of the low refractive index film 32 is 56 nm, the film thickness of the high refractive index film 33 is 40 nm, the film thickness of the low refractive index film 34 is 17 nm, and the high refractive index film 35. The thickness of the low refractive index film 36 is 48 nm.

  According to such a structure, for example, when an ITO film having a film thickness of 10 nm to 30 nm, particularly 15 nm to 25 nm is formed, the transmittance of light having wavelengths of 450 nm, 550 nm, and 650 nm is 94% or more. In addition, the fluctuation value of the transmittance of light in the wavelength range of 400 nm to 700 nm can be set to 2% or less. Further, by using a tantalum oxide film as the high refractive index film 3 (H), the film is excellent in heat resistance, and damage to the high refractive index film 3 (H) when forming the ITO film is suppressed, and productivity is increased. It can be made excellent. Furthermore, since the respective film thicknesses are not excessively thin and are not excessively thick, the film formation can be easily controlled, thereby further improving the productivity.

  The liquid crystal projector substrate 1 of the present invention may be one in which only the laminated film 3 is formed on the substrate body 2 as shown in FIG. 1, for example, the substrate of the laminated film 3 as shown in FIG. A light-shielding member 4 called a so-called black matrix is formed on the side opposite to the main body 2 side (the upper side in the figure), and the ITO film 5 as described above is formed on substantially the entire surface so as to cover the light-shielding member 4. May be. For example, as shown in FIG. 3, the laminated film 3 may be formed only on a portion of the substrate body 2 where the light blocking member 4 is not formed. The configuration shown in FIG. 2 is preferable in terms of productivity.

  In such a liquid crystal projector substrate 1, a total of 6 layers of high refractive index films 3 (H) and low refractive index films 3 (L) are alternately laminated on a substrate body 2 by a known sputtering method. Can be manufactured. Examples of the sputtering method include a DC (direct current) sputtering method, an AC (alternating current) sputtering method, a high-frequency sputtering method, and a magnetron sputtering method. From the viewpoints of controlling the film thickness, the DC magnetron sputtering method and the AC magnetron sputtering method are preferable.

  In addition to the sputtering method, a vacuum deposition method can also be used. Examples of the vacuum deposition method include an ion plating method and an ion assist method. In general, the DC magnetron sputtering method, the AC magnetron sputtering method, the ion plating method, and the ion assist method are preferable because the process is stable, the film formation on a large area is easy, and the film thickness control accuracy is stable. .

  For the tantalum oxide layer, titanium oxide, zirconium oxide, and hafnium oxide as the high refractive index film 3 (H), for example, a target composed of a metal element constituting these metal oxides is used, and oxygen is contained as a sputtering gas. It can be easily formed by a reactive sputtering method using a gas to be used. The silicon oxide layer as the low refractive index film 3 (L) can be easily formed by reactive sputtering using, for example, silicon carbide as a target and a gas containing oxygen as a sputtering gas. The target may be doped with a known dopant such as Al, Si, Zn or the like as long as not departing from the spirit of the present invention.

  FIG. 4 is a cross-sectional view showing the liquid crystal panel of the present invention. The liquid crystal panel 11 is sealed between a main substrate 12, the liquid crystal projector substrate 1 of the present invention which is a counter substrate disposed opposite to the main substrate 12, and the main substrate 12 and the liquid crystal projector substrate 1. Liquid crystal 13 to be used. On the main substrate 12, display electrodes 12 a that orient the liquid crystal 13 by applying a voltage are formed. The liquid crystal projector substrate 1 is arranged such that the main surface side on which the light shielding member 4 and the ITO film 5 are formed is the inner side (the liquid crystal 13 side). For example, dustproof glasses 14 and 15 for protecting the liquid crystal panel 11 from dust in the air may be disposed outside the main substrate 12 or the liquid crystal projector substrate 1.

  Such a liquid crystal panel 11 is disposed and used inside a liquid crystal projector. Light from a light source (not shown) enters the liquid crystal panel 11 from the main substrate 12 side. The incident light is modulated by the liquid crystal panel 11 and emitted from the liquid crystal projector substrate 1 side, and is arranged outside by a projection lens (not shown). Projected onto the projected object. For such a liquid crystal panel 11 and a liquid crystal projector, since the liquid crystal projector substrate 1 is excellent in the transmittance of light of each wavelength of R, G, and B, and its fluctuation is suppressed, the brightness is improved. In addition to being excellent in performance as a projector, power consumption is reduced and the environment is considered.

  Hereinafter, the present invention will be specifically described with reference to examples.

Example 1
A tantalum oxide film as a high refractive index film and a silicon oxide film as a low refractive index film are alternately measured in three layers on a quartz substrate having a thickness of 1.2 mm as a substrate body by the following method. Six layers were laminated to form a laminated film. In addition, the film thickness of each refractive index film which becomes the first to sixth layers from the substrate main body side in the laminated film was as shown in Table 1. Thereafter, an ITO film having a film thickness of 20 nm was formed on the surface of the laminated film opposite to the substrate main body by the method as described below to manufacture a liquid crystal projector substrate.

(Formation of tantalum oxide film)
A Ta target as a sputtering target was placed on the cathode in the vacuum chamber, and after the vacuum chamber was evacuated to 2.0 × 10 ⁻³ Pa or less, oxygen gas 60 sccm and argon gas 140 sccm were introduced as sputtering gas. . The pressure at this time was 3.0 × 10 ⁻¹ Pa. In this state, reactive sputtering was performed using a DC pulse power source, whereby a tantalum oxide film was formed on a quartz substrate or a laminated film sequentially formed as an object to be processed installed in a vacuum chamber.

(Formation of silicon oxide film)
A Si target as a sputtering target was placed on the cathode in the vacuum chamber, and after the vacuum chamber was evacuated to 2.0 × 10 ⁻³ Pa or less, argon gas 210 sccm and oxygen gas 190 sccm were introduced as sputtering gases. . The pressure at this time was 3.4 × 10 ⁻¹ Pa. In this state, by performing reactive sputtering using an AC power source, a silicon oxide film was formed on a quartz substrate that was sequentially formed on a quartz substrate as an object to be processed installed in a vacuum chamber.

(Formation of ITO film)
It formed by sputtering method.

(Comparative Example 1)
A liquid crystal projector substrate was manufactured by directly forming an ITO film having a thickness of 20 nm on the same quartz substrate as in Example 1 without forming a laminated film composed of a high refractive index film and a low refractive index film. .

(Comparative Example 2)
In the same manner as in Example 1, after a high-refractive index film (tantalum oxide film) and a low-refractive index film (silicon oxide film) were alternately stacked on a quartz substrate in a total of four layers to form a stacked film, A liquid crystal projector substrate was manufactured by forming an ITO film having a thickness of 20 nm. In addition, the film thickness of each refractive index film which becomes the first layer to the fourth layer from the substrate main body side in the laminated film is as shown in Table 1.

(Comparative Example 3)
In the same manner as in Example 1, a high refractive index film (tantalum oxide film) and a low refractive index film (silicon oxide film) are alternately stacked on a quartz substrate, and three high refractive index films and two layers of low refractive index are stacked. After forming a total of five laminated films composed of a rate film, an ITO film having a thickness of 20 nm was formed to manufacture a liquid crystal projector substrate. In addition, the film thickness of each refractive index film which becomes the first layer to the fifth layer from the substrate main body side in the laminated film is as shown in Table 1.

  Next, the transmittance of the liquid crystal projector substrates of Example 1 and Comparative Examples 1 to 3 was evaluated. The transmittance was evaluated with a Hitachi U4000 type self-recording spectrophotometer. The results of the liquid crystal projector substrates of Example 1 and Comparative Example 1 are shown in FIG. 5, and the results of the liquid crystal projector substrates of Comparative Examples 2 and 3 are shown in FIG. FIG. 6 also shows the results of the liquid crystal projector substrate of Example 1 for comparison.

  As is apparent from FIG. 5, the transmittance of the liquid crystal projector substrate of Comparative Example 1 in which the laminated film having the predetermined film thickness composed of the high refractive index film and the low refractive index film is not formed is about 90% at the maximum. On the other hand, with respect to the liquid crystal projector substrate of Example 1, it is recognized that the light transmittance of any of wavelengths 450 nm, 550 nm, and 650 nm is 93% or more, and the wavelength is 400 nm or more and 700 nm or less. It is recognized that the fluctuation value of the light transmittance in the range of 4% or less is also 4% or less.

  Further, as is apparent from FIG. 6, the substrate for the liquid crystal projector of Comparative Example 2 in which the number of layers of the laminated film is 4 has a relatively high transmittance, but there is a slight variation in the transmittance. It is recognized that the liquid crystal projector substrate of Comparative Example 3 having 5 layers has a low transmittance and a large variation.

(Examples 2 and 3)
The substrates for liquid crystal projectors of Examples 2 and 3 were manufactured in the same manner as Example 1 except that the thickness of each refractive index film of the laminated film was as shown in Table 2. The liquid crystal projector substrate of Example 2 is obtained by adjusting the thickness of the second refractive index film in the laminated film to 20 nm and adjusting the film thickness of other refractive index films. Mainly, the second refractive index film in the laminated film is 70 nm, and the film thickness of the other refractive index film is adjusted. With respect to the liquid crystal projector substrates of Examples 2 and 3, the transmittance was evaluated in the same manner as in Example 1. The results are shown in FIG.

  As is clear from FIG. 7, the liquid crystal projector substrates of Examples 2 and 3 in which the second refractive index film in the laminated film is 20 nm and 70 nm are more transparent than the liquid crystal projector substrate of Example 1. However, the transmittance of light of any wavelength of 450 nm, 550 nm, and 650 nm is 92% or more, and the wavelength is in the range of 400 nm to 700 nm. The variation value of the light transmittance is also 4% or less, and it is recognized that the light transmittance still has sufficient characteristics.

(Examples 4 and 5)
The substrates for liquid crystal projectors of Examples 4 and 5 were manufactured in the same manner as Example 1 except that the thickness of each refractive index film of the laminated film was as shown in Table 3. Note that the liquid crystal projector substrate of Example 4 is one in which the refractive index film of the fifth layer in the laminated film is mainly 30 nm and the film thickness of the other refractive index film is adjusted. Mainly, the refractive index film of the fifth layer in the laminated film is 130 nm, and the film thicknesses of the other refractive index films are adjusted. The liquid crystal projector substrates of Examples 4 and 5 were evaluated for transmittance in the same manner as in Example 1. The results are shown in FIG.

  As is clear from FIG. 8, the liquid crystal projector substrates of Examples 4 and 5 in which the fifth refractive index film in the laminated film is 30 nm and 130 nm are also more transparent than the liquid crystal projector substrate of Example 1. However, the transmittance of light having wavelengths of 450 nm, 550 nm, and 650 nm is 92% or more, and the transmittance of light having a wavelength in the range of 400 nm to 700 nm is also reduced. It is recognized that the fluctuation value is 4% or less and still has sufficient characteristics.

  DESCRIPTION OF SYMBOLS 1 ... Substrate for liquid crystal projectors, 2 ... Substrate body, 3 ... Laminated film, 3 (H) ... High refractive index film, 3 (L) ... Low refractive index film, 4 ... Light shielding member, 5 ... ITO film, 11 ... Liquid crystal panel, 12 ... main substrate, 13 ... liquid crystal, 14, 15 ... dust-proof glass, 31 ... high refractive index film, 32 ... low refractive index film, 33 ... high refractive index film, 34 ... low refractive index film, 35 ... high Refractive index film, 36 ... low refractive index film

Claims (12)

A substrate for a liquid crystal projector, comprising: a substrate body; a laminated film laminated on the substrate body; and an ITO film provided on a surface of the laminated film opposite to the substrate body side ,
The laminated film has three layers of alternating high refractive index films having a refractive index of 1.9 to 2.5 and low refractive index films having a refractive index of 1.2 to 1.5 in order from the substrate body side. A total of 6 layers are laminated, and the film thickness of the laminated film is 155 nm or more and 250 nm or less , and the film thickness of the refractive index film that is the first layer from the substrate body side in the laminated film is 5 nm or more and 25 nm or less. The film thickness of the refractive index film as the layer is 15 nm or more and 75 nm or less, the film thickness of the refractive index film as the third layer is 5 nm or more and 45 nm or less, and the film thickness of the refractive index film as the fourth layer is 5 nm or more and 35 nm or less. The thickness of the fifth refractive index film is 25 nm to 135 nm, the thickness of the sixth refractive index film is 40 nm to 55 nm, and the light transmittance is 450 nm, 550 nm, and 650 nm. it is characterized in that at least 92% Substrate for a liquid crystal projector. The high refractive index film, tantalum oxide, titanium oxide, zirconium oxide, and a substrate for a liquid crystal projector according to claim 1 Symbol mounting, characterized in that it consists of at least one selected from the group consisting of hafnium oxide. 3. The liquid crystal projector substrate according to claim 1, wherein the low refractive index film is made of at least one selected from silicon oxide and magnesium fluoride. According to claim 1, wherein the surface roughness of the opposite surface is 0.5nm or less and the substrate main body side of the refractive index film serving as the 6 th layer from the substrate main body side of the laminated film The substrate for liquid crystal projectors of any one of Claims 1. The total thickness of the two layers of the refractive index film as the second layer and the refractive index film as the fifth layer from the substrate body side in the laminated film is 60 nm or more and 165 nm or less. 5. The liquid crystal projector substrate according to any one of 1 to 4 . Any one of claims 1 to 5, wherein the total thickness of the high refractive index film of the odd-th layer and comprising a total of three layers from the substrate main body side of the laminated film is 60nm or more 155nm or less LCD projector substrate. Any one of claims 1 to 6, characterized in that the total thickness of the low refractive index film of the even-th layer and comprising a total of three layers from the substrate main body side of the laminated film is 80nm or more 155nm or less LCD projector substrate. Substrate for a liquid crystal projector of any one of claims 1 to 7, wherein the thickness of the ITO film is 10nm or more 30nm or less. Any one of claims 1 to 8, wherein the variation value wavelength is expressed by the difference between the maximum value and the minimum value of the transmittance of light of 700nm or less in the range of 400nm is not more than 4% LCD projector substrate. Substrate for a liquid crystal projector of any one of claims 1 to 9, characterized in that the substrate body is a quartz substrate. A liquid crystal panel for a liquid crystal projector having a pair of substrates disposed opposite to each other and a liquid crystal disposed between the pair of substrates,
11. A liquid crystal projector liquid crystal panel, wherein one of the substrates is a liquid crystal projector substrate according to any one of claims 1 to 10 . A liquid crystal projector having a liquid crystal panel for forming image information to be projected onto a projection object,
A liquid crystal projector according to claim 11, wherein the liquid crystal panel is a liquid crystal panel for a liquid crystal projector.

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