JP6673378B2 - Liquid crystal devices, electronic devices, projection display devices - Google Patents

Description

  The present invention relates to a reflection type liquid crystal device, an electronic device, and a projection type display device.

  As a reflection-type liquid crystal device, for example, in Patent Document 1, a reflection electrode is formed in a matrix on a substrate, a transistor is formed corresponding to each reflection electrode, and a passivation film is formed on the reflection electrode. There is disclosed a reflective liquid crystal panel in which a liquid crystal panel substrate and a light incident side substrate are arranged with a gap, and liquid crystal is sealed in the gap.

  In the liquid crystal panel of Patent Document 1, the use of a silicon oxide film having a thickness of 500 to 2,000 angstroms as a passivation film makes it possible to reduce a change in reflectance due to a variation in the thickness of the passivation film. Further, the thickness of the passivation film is set within an appropriate range according to the wavelength of light incident on the liquid crystal panel.

JP-A-2004-4885

  Patent Literature 1 discloses a projector using a reflective liquid crystal panel as a light valve. A reflective liquid crystal panel used as a light valve receives stronger light from a light source than a direct-view liquid crystal panel. When an inorganic alignment film obtained by obliquely depositing an inorganic compound such as silicon oxide is used as an alignment film in such a reflective liquid crystal panel, the inorganic alignment film and the liquid crystal material undergo a photoreaction by incident light. It is known that the liquid crystal material is easily deteriorated.

  The inventor of the present application has investigated the cause of the deterioration of the liquid crystal material due to the photoreaction, and in the reflection type liquid crystal panel, a standing wave is generated by interference between the light incident from the light source and the light reflected by the reflection electrode, It has been found that when the antinode of the standing wave at which the power density of the standing wave is high is located near the interface between the inorganic alignment film and the liquid crystal layer, the photoreaction proceeds and the liquid crystal material is easily deteriorated. Also, the degree of deterioration of the liquid crystal material due to the photoreaction varies among individual liquid crystal panels, and one of the factors of the variation is that the position of the interface between the inorganic alignment film and the liquid crystal layer on the substrate varies. I found it.

  That is, even if the material and the thickness of the passivation film formed on the reflective electrode are specified as in the reflection type liquid crystal panel of Patent Document 1, the antinode of the standing wave, the inorganic alignment film and the liquid crystal layer may not be formed. However, since the positional relationship with the interface is not always in a favorable state, there is a problem that variation in deterioration of the liquid crystal material due to photoreaction cannot be suppressed.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following embodiments.

A liquid crystal device according to the present application includes a first substrate having a reflective first electrode , a first insulating film that covers the first electrode , a first alignment film that is an obliquely deposited film on the first insulating film , A second electrode having a second orientation film, a second alignment film that is an obliquely deposited film, and a liquid crystal layer provided between the first substrate and the second substrate. A plurality of regions having different optical distances D between the pixel and the center of the first alignment film in the thickness direction are provided in the pixel, and a difference ΔD between the optical distances D in the plurality of regions is as follows. Equation (1) is satisfied.
0.225λ ≦ ΔD ≦ 0.275λ (1)
(Λ is the wavelength of light incident on the first electrode)

  In the above liquid crystal device, the plurality of regions include a first region and a second region having different optical distances D, and an area ratio of the first region to an opening area of the pixel and a ratio of the second region to the opening area of the pixel. It is preferable that the area ratio is the same.

In the above liquid crystal device, it is preferable that the difference ΔD between the optical distances D in the plurality of regions satisfies the following expression (1).
0.225λ ≦ ΔD ≦ 0.275λ (1)
(Λ is the wavelength of light incident on the first electrode)

In the above liquid crystal device, it is more preferable that the difference ΔD between the optical distances D in the plurality of regions satisfies the following expression (2).
ΔD = 0.25λ (2)

In the liquid crystal device described above, the thickness of Oite the first electrode to the plurality of regions are different from each other, respectively.

Alternatively, the liquid crystal device described above may be respectively made different thickness of Oite the first insulating film on the plurality of regions.

  In the above-described liquid crystal device, it is preferable that a boundary between the plurality of regions is parallel or perpendicular to a vibration direction of an electric field of incident light.

  In the above liquid crystal device, it is preferable that the boundary between the plurality of regions is parallel or perpendicular to the vibration direction of the electric field of the incident light, and the first electrode forms an inclined surface at the boundary between the plurality of regions. .

  In the above liquid crystal device, the boundary between the plurality of regions may be parallel or perpendicular to the vibration direction of the electric field of the incident light, and the first insulating film may have a slope at the boundary between the plurality of regions. preferable.

In the above liquid crystal device, it is preferable that a transistor be provided in the pixel as a switching element, and that a contact portion for electrically connecting the transistor and the first electrode overlap a boundary portion of the plurality of regions in plan view. .

  According to another aspect of the invention, there is provided an electronic apparatus including the above-described liquid crystal device.

  The projection type display device of the present application is a lighting device that can emit three color lights, a first light modulation unit that modulates red light among three color lights, and a second light modulation that modulates green light among three color lights. Means, third light modulating means for modulating blue light of the three color lights, and light modulated by each of the first light modulating means, second light modulating means, and third light modulating means, and display light. And a projection lens for projecting display light, wherein at least the third light modulator among the first light modulator, the second light modulator, and the third light modulator has the liquid crystal device. It is characterized by being used.

FIG. 1 is a schematic plan view illustrating a configuration of a liquid crystal device according to a first embodiment. FIG. 2 is a schematic sectional view taken along the line H-H ′ shown in FIG. 1. FIG. 2 is an equivalent circuit diagram illustrating an electrical configuration of the liquid crystal device according to the first embodiment. FIG. 2 is a schematic cross-sectional view illustrating a structure of a pixel of the liquid crystal device according to the first embodiment. 5 is a graph showing a power density of a standing wave S generated near a pixel electrode of the element substrate shown in FIG. FIG. 2 is a schematic plan view illustrating a planar configuration of a pixel in the liquid crystal device according to the first embodiment. FIG. 7 is a schematic cross-sectional view showing the structure of a pixel along the line A-A ′ in FIG. 6. 4 is a graph in which the power density (PD) of the standing wave S is approximated to a sine wave under a predetermined condition. 9 is a graph showing power densities PD (A), PD (B), and PD (AB) of the standing wave S when Δd is set to 0.25λ / n ₁ . 9 is a graph showing the power densities PD (A), PD (B), and PD (AB) of the standing wave S when Δd is set to 0.225λ / n ₁ . 9 is a graph showing the power densities PD (A), PD (B), and PD (AB) of the standing wave S when Δd is set to 0.275λ / n ₁ . FIG. 7 is a schematic cross-sectional view illustrating a structure of a pixel in a liquid crystal device according to a second embodiment. FIG. 1 is a schematic diagram illustrating a configuration of a three-panel reflective liquid crystal projector that is an example of a projection display device as an electronic apparatus. FIG. 11 is a schematic plan view showing an arrangement of a plurality of regions having different optical distances D in pixels P of a modified example. FIG. 11 is a schematic plan view showing an arrangement of a plurality of regions having different optical distances D in pixels P of a modified example. FIG. 11 is a schematic plan view showing an arrangement of a plurality of regions having different optical distances D in pixels P of a modified example. FIG. 11 is a schematic cross-sectional view illustrating a structure of a pixel of a liquid crystal device according to a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings used are appropriately enlarged or reduced so that the portions to be described can be recognized.

  In the present embodiment, an active matrix type liquid crystal device including a thin film transistor (TFT) as a pixel switching element will be described as an example. This liquid crystal device can be suitably used, for example, as a light modulator (liquid crystal light valve) of a projection display device (liquid crystal projector) described later.

(1st Embodiment)
<Liquid crystal device>
First, the liquid crystal device of the present embodiment will be described with reference to FIGS. FIG. 1 is a schematic plan view showing the configuration of the liquid crystal device according to the first embodiment, FIG. 2 is a schematic sectional view taken along line HH ′ shown in FIG. 1, and FIG. 3 is an electrical diagram of the liquid crystal device according to the first embodiment. FIG. 3 is an equivalent circuit diagram showing a configuration.

  As shown in FIGS. 1 and 2, the liquid crystal device 100 according to the present embodiment includes an element substrate 10 and a counter substrate 20 as a pair of substrates disposed to face each other, and a liquid crystal layer 50 sandwiched between the pair of substrates. Have. As the base material 10s of the element substrate 10 and the base material 20s of the counter substrate 20, for example, a transparent quartz substrate or a glass substrate is used.

The element substrate 10 is larger than the opposing substrate 20, and the two substrates are bonded to each other with a gap therebetween via a seal portion 40 arranged along the outer edge of the opposing substrate 20. A portion of the seal portion 40 interrupted is an injection port 41, and liquid crystal is injected from the injection port 41 at the above interval by a vacuum injection method, and the injection port 41 is sealed using a sealant 42. Note that the method of sealing the liquid crystal at the above intervals is not limited to the vacuum injection method. For example, the liquid crystal is dropped inside the sealing portion 40 arranged in a frame shape, and the liquid crystal is sealed with the element substrate 10 under reduced pressure. An ODF (One Drop Fill) method of bonding the counter substrate 20 may be employed.
For the seal portion 40, for example, an adhesive such as a thermosetting or ultraviolet curable epoxy resin is employed. A spacer (not shown) for keeping the distance between the pair of substrates constant is mixed in the seal portion 40.

  Inside the seal portion 40, a display area E1 including a plurality of pixels P arranged in a matrix is provided. Further, a parting-off portion 21 is provided in a peripheral region E2 between the seal portion 40 and the display region E1 so as to surround the display region E1. The parting-off part 21 is made of, for example, a light-shielding metal, alloy, or metal compound.

  The element substrate 10 is provided with a terminal portion in which a plurality of external connection terminals 104 are arranged. A data line driving circuit 101 is provided between the first side portion along the terminal portion and the seal portion 40. In addition, an inspection circuit 103 is provided between the seal portion 40 along the second side facing the first side and the display area E1. Further, a scanning line driving circuit 102 is provided between the seal portion 40 and the display area E1 along the third and fourth sides orthogonal to the first side and facing each other. A plurality of wirings 105 that connect the two scanning line driving circuits 102 are provided between the seal portion 40 on the second side and the inspection circuit 103.

Wirings connected to the data line driving circuit 101 and the scanning line driving circuit 102 are connected to a plurality of external connection terminals 104 arranged along the first side. Note that the arrangement of the inspection circuit 103 is not limited to this, and may be provided at a position along the inside of the seal portion 40 between the data line driving circuit 101 and the display area E1.
Hereinafter, the direction along the first side will be referred to as the X direction, and the direction along the third side will be referred to as the Y direction. Viewing along the direction from the counter substrate 20 side toward the element substrate 10 side is referred to as “plan view” or “planar”.

  As shown in FIG. 2, on the surface of the element substrate 10 on the liquid crystal layer 50 side, a reflective pixel electrode 15 provided for each pixel P and a thin film transistor (hereinafter referred to as a TFT) 30 as a switching element are provided. , Signal wiring, and an alignment film 18 covering them. Further, a light-shielding structure for preventing the switching operation from becoming unstable due to light incident on the semiconductor layer in the TFT 30 is employed. The element substrate 10 is an example of a first substrate of the present invention, and includes a substrate 10s, a pixel electrode 15 as a first electrode formed on the substrate 10s, a TFT 30 as a transistor, a signal wiring, and a first alignment. It includes an alignment film 18 as a film.

  The counter substrate 20 facing the element substrate 10 is an example of a second substrate in the present invention, and includes a base material 20s, a parting portion 21 formed on the base material 20s, and a film formed so as to cover the base part 20s. Flattened layer 22, a common electrode 23 covering the flattened layer 22 and provided at least over the display region E <b> 1 as a light-transmitting second electrode, and a second alignment film covering the common electrode 23. And an alignment film 24.

  The parting part 21 surrounds the display area E1 as shown in FIG. 1 and is provided at a position overlapping the scanning line driving circuit 102 and the inspection circuit 103 in a plane. Thus, the light incident on these circuits from the counter substrate 20 side is shielded, and these circuits play a role in preventing malfunctions due to the light. Further, unnecessary stray light is shielded so as not to enter the display area E1, and high contrast in display of the display area E1 is secured.

  The flattening layer 22 is made of, for example, an inorganic material such as silicon oxide, and is provided so as to have light transmittance and cover the parting portion 21. As a method of forming such a flattening layer 22, for example, a method of forming a film using a plasma CVD method or the like can be given.

  The common electrode 23 is made of, for example, a transparent conductive film such as ITO (Indium Tin Oxide), covers the flattening layer 22 and, as shown in FIG. Is electrically connected to The vertical conducting part 106 is electrically connected to the wiring on the element substrate 10 side.

  The alignment film 18 covering the pixel electrode 15 and the alignment film 24 covering the common electrode 23 are selected based on the optical design of the liquid crystal device 100. The alignment films 18 and 24 are formed of, for example, an organic material such as polyimide, and rubbed on the surface thereof to substantially horizontally align liquid crystal molecules having positive dielectric anisotropy, or SiOx ( An inorganic alignment film (oblique vapor deposition film) that obliquely vapor-deposits an inorganic material such as silicon oxide) and substantially vertically aligns liquid crystal molecules having negative dielectric anisotropy.

Such a liquid crystal device 100 is of a reflective type, and has a normally white mode in which the reflectance of the pixel P is maximum when no voltage is applied, and a normally black mode in which the reflectance of the pixel P is minimum when no voltage is applied. A mode optical design is employed. A polarizing element is arranged and used on the light incident side of the liquid crystal panel 110 including the element substrate 10 and the counter substrate 20 according to the optical design.
In the present embodiment, an example in which the above-described inorganic alignment films and liquid crystals having negative dielectric anisotropy are used as the alignment films 18 and 24 and an optical design of a normally black mode is applied will be described below.

  Next, an electrical configuration of the liquid crystal device 100 will be described with reference to FIG. The liquid crystal device 100 includes a plurality of scanning lines 3a and a plurality of data lines 6a as signal wirings which are insulated from each other and are orthogonal to each other at least in the display region E1, and a capacitance line 3b arranged in parallel along the data lines 6a. . The direction in which the scanning lines 3a extend is the X direction, and the direction in which the data lines 6a extend is the Y direction.

  The pixel electrode 15, the TFT 30, and the storage capacitor 31 are provided in a region divided by the scanning line 3a, the data line 6a, the capacitor line 3b, and these signal lines, and these constitute a pixel circuit of the pixel P. doing.

  The scanning line 3a is electrically connected to the gate of the TFT 30, and the data line 6a is electrically connected to the source of the TFT 30. The pixel electrode 15 is electrically connected to the drain of the TFT 30.

  The data line 6a is connected to the data line driving circuit 101 (see FIG. 1), and supplies the image signals D1, D2,..., Dn supplied from the data line driving circuit 101 to the pixels P. The scanning line 3a is connected to the scanning line driving circuit 102 (see FIG. 1), and supplies the scanning signals SC1, SC2,..., SCm supplied from the scanning line driving circuit 102 to the pixels P.

  The image signals D1 to Dn supplied from the data line driving circuit 101 to the data lines 6a may be supplied line-sequentially in this order, or may be supplied in groups to a plurality of data lines 6a adjacent to each other. Good. The scanning line driving circuit 102 supplies the scanning signals SC1 to SCm to the scanning line 3a in a pulsed line-sequential manner at a predetermined timing.

  In the liquid crystal device 100, the image signal D1 to Dn supplied from the data line 6a is supplied to the pixel electrode 15 at a predetermined timing by turning on the TFT 30 as a switching element for a predetermined period by input of the scanning signals SC1 to SCm. Is written in the file. The image signals D1 to Dn of a predetermined level written to the liquid crystal layer 50 via the pixel electrode 15 are held for a certain period between the pixel electrode 15 and the common electrode 23 opposed to each other via the liquid crystal layer 50. You. The frequency of the image signals D1 to Dn is, for example, 60 Hz.

  In order to prevent the held image signals D1 to Dn from leaking, a storage capacitor 31 is connected in parallel with a liquid crystal capacitor formed between the pixel electrode 15 and the common electrode 23. The storage capacitor 31 is provided between the drain of the TFT 30 and the capacitor line 3b.

  The test circuit 103 shown in FIG. 1 is connected to the data line 6a. In the manufacturing process of the liquid crystal device 100, an operation defect or the like of the liquid crystal device 100 can be confirmed by detecting the image signal. However, illustration is omitted in the equivalent circuit of FIG.

  Peripheral circuits for driving and controlling the pixel circuit in the present embodiment include a data line driving circuit 101, a scanning line driving circuit 102, and an inspection circuit 103. Further, the peripheral circuit includes a sampling circuit that samples the image signal and supplies it to the data line 6a, and a precharge circuit that supplies a precharge signal of a predetermined voltage level to the data line 6a prior to the image signal. Is also good.

  Next, the structure of the pixel P in the liquid crystal device 100 (liquid crystal panel 110) of the present embodiment will be described. FIG. 4 is a schematic sectional view showing the structure of the pixel of the liquid crystal device according to the first embodiment.

  As shown in FIG. 4, the scanning lines 3a are first formed on the base material 10s of the element substrate 10. The scanning line 3a is made of, for example, a single metal, alloy, metal silicide, or polymetal containing at least one of metals such as Ti (titanium), Cr (chromium), W (tungsten), Ta (tantalum), and Mo (molybdenum). Silicide, nitride, or a laminate of these can be used and has light-shielding properties.

  A base insulating film 11a made of, for example, silicon oxide or the like is formed so as to cover the scanning lines 3a, and a semiconductor layer 30a is formed in an island shape on the base insulating film 11a. The semiconductor layer 30a is made of, for example, a polycrystalline silicon film, into which impurity ions are implanted, and has an LDD (Lightly Doped Drain) structure having a first source / drain region, a junction region, a channel region, a junction region, and a second source / drain region. Are formed.

  Gate insulating film 11b is formed to cover semiconductor layer 30a. Further, a gate electrode 30g is formed at a position facing the channel region with the gate insulating film 11b interposed therebetween.

  A first interlayer insulating film 11c is formed so as to cover gate electrode 30g and gate insulating film 11b, and penetrates gate insulating film 11b and first interlayer insulating film 11c at positions overlapping respective ends of semiconductor layer 30a. Two contact holes CNT1 and CNT2 are formed.

  Then, a conductive film is formed using a light-shielding conductive material such as Al (aluminum) or an alloy thereof so as to fill the two contact holes CNT1 and CNT2 and cover the first interlayer insulating film 11c, and pattern the conductive film. Thereby, the data line 6a connected to the first source / drain region via the contact hole CNT1 is formed. At the same time, a first relay electrode 6b connected to the second source / drain region via the contact hole CNT2 is formed.

  Next, a second interlayer insulating film 12 is formed to cover the data line 6a, the first relay electrode 6b, and the first interlayer insulating film 11c. The second interlayer insulating film 12 is made of, for example, silicon oxide or nitride. Then, a flattening process for flattening unevenness of the surface caused by covering the region where the TFT 30 is provided is performed. As a method of the flattening process, for example, a chemical mechanical polishing process (Chemical Mechanical Polishing: CMP process), a spin coating process, or the like can be given.

  A contact hole CNT3 penetrating through the second interlayer insulating film 12 is formed at a position overlapping the first relay electrode 6b. A conductive film made of, for example, a light-shielding metal such as Al (aluminum) or an alloy thereof is formed so as to cover the contact hole CNT3 and the second interlayer insulating film 12, and pattern the wiring. And a second relay electrode 7b electrically connected to the first relay electrode 6b via the contact hole CNT3. The wiring 7a is formed so as to overlap the semiconductor layer 30a of the TFT 30 and the data line 6a in a plane, and is provided with a fixed potential and functions as a shield layer.

  A third interlayer insulating film 13a is formed so as to cover wiring 7a and second relay electrode 7b. The third interlayer insulating film 13a can also be formed using, for example, silicon oxide, nitride, or oxynitride.

  A contact hole CNT4 is formed in the third interlayer insulating film 13a at a position overlapping with the second relay electrode 7b. A conductive film made of a light-shielding metal such as TiN (titanium nitride) is formed so as to cover the contact hole CNT4 and cover the third interlayer insulating film 13a, and by patterning the conductive film, the first capacitor electrode 31a is formed. And the third relay electrode 31d.

  The protection film 13b is formed by patterning so as to cover an outer edge of a portion of the first capacitance electrode 31a facing the second capacitance electrode 31b via the dielectric layer 31c to be formed later. Further, the protective film 13b is formed by patterning so as to cover the outer edge of the third relay electrode 31d except for the portion overlapping the contact hole CNT5.

A dielectric layer 31c is formed to cover the protection film 13b and the first capacitance electrode 31a. As the dielectric layer 31c, a silicon nitride film, a single layer film of hafnium oxide (HfO ₂ ), alumina (Al ₂ O ₃ ), tantalum oxide (Ta ₂ O ₅ ), or at least one of these single layer films A multilayer film in which two types of single-layer films are stacked may be used. The portion of the dielectric layer 31c that overlaps the third relay electrode 31d in a plane is removed by etching or the like. A conductive film such as, for example, TiN (titanium nitride) is formed so as to cover the dielectric layer 31c, and by patterning the conductive film, the second capacitor electrode is disposed to face the first capacitor electrode 31a and is connected to the third relay electrode 31d. 31b is formed. The first capacitance electrode 31a and the second capacitance electrode 31b opposed to each other with the dielectric layer 31c interposed therebetween constitute the storage capacitance 31.

  Next, a fourth interlayer insulating film 14 covering the second capacitor electrode 31b and the dielectric layer 31c is formed. The fourth interlayer insulating film 14 is also made of, for example, silicon oxide or nitride, and is subjected to a planarization process such as a CMP process. A contact hole CNT5 penetrating through the fourth interlayer insulating film 14 is formed to reach a portion of the second capacitance electrode 31b which is in contact with the third relay electrode 31d.

  A reflective conductive film (electrode film) such as Al is formed to cover the contact hole CNT5 and cover the fourth interlayer insulating film. The conductive film (electrode film) is patterned to form the pixel electrode 15 electrically connected to the second capacitance electrode 31b and the third relay electrode 31d via the contact hole CNT5.

  The second capacitance electrode 31b is electrically connected to the drain of the TFT 30 via the third relay electrode 31d, the contact hole CNT4, the second relay electrode 7b, the contact hole CNT3, and the first relay electrode 6b, and serves as a contact portion. It is electrically connected to the pixel electrode 15 via the contact hole CNT5.

  The first capacitance electrode 31a is formed so as to straddle a plurality of pixels P, and functions as a capacitance line 3b in an equivalent circuit (see FIG. 3). A fixed potential is applied to the first capacitance electrode 31a. Thus, the potential applied to the pixel electrode 15 via the drain of the TFT 30 can be held between the first capacitance electrode 31a and the second capacitance electrode 31b.

  As described above, a plurality of wirings are formed on the base material 10s of the element substrate 10, and the wiring layers are represented by using the symbols of the insulating film or the interlayer insulating film for insulating between the wirings. That is, the base insulating film 11a, the gate insulating film 11b, and the first interlayer insulating film 11c are collectively called a wiring layer 11. A typical wiring of the wiring layer 11 is the scanning line 3a. A representative wiring of the wiring layer 12 including the second interlayer insulating film 12 is the data line 6a. The third interlayer insulating film 13a, the protective film 13b, and the dielectric layer 31c are collectively called a wiring layer 13, and a typical wiring is the wiring 7a. Similarly, a representative wiring of the wiring layer 14 including the fourth interlayer insulating film 14 is a first capacitance electrode 31a functioning as the capacitance line 3b. The wiring structure of the element substrate 10 is not limited to this.

  A first insulating film 16 is formed so as to cover the pixel electrode 15, and an alignment film 18 is formed on the first insulating film 16. Further, an alignment film 24 is formed so as to cover the common electrode 23 of the counter substrate 20 which is disposed to face the element substrate 10 with the liquid crystal layer 50 interposed therebetween. The first insulating film 16 in the present embodiment is, for example, a deposited film of silicon oxide. As described above, the alignment films 18 and 24 are inorganic alignment films, and are an aggregate of columnar members 18a and 24a in which an inorganic material such as silicon oxide is obliquely vapor-deposited from a predetermined direction and deposited in a columnar shape. The liquid crystal molecules LC having a negative dielectric anisotropy with respect to the alignment films 18 and 24 have a pretilt of 3 to 5 degrees in the inclination direction of the columnar bodies 18a and 24a with respect to the normal direction of the alignment film surface. Substantially vertical alignment (VA; Vertical Alignment) having an angle θp. By applying an AC voltage (drive signal) between the pixel electrode 15 and the common electrode 23 to drive the liquid crystal layer 50, the liquid crystal molecules LC are inclined in the direction of the electric field generated between the pixel electrode 15 and the common electrode 23. Behaves (vibrates). In other words, the liquid crystal molecules LC vibrate in the pretilt direction.

<Structure for improving variation in light resistance life>
Next, a configuration for improving the variation of the light-proof life in the liquid crystal device 100 will be described with reference to FIGS. The liquid crystal device 100 according to the present embodiment is used as a light valve in a projection display device described later, and strong light from a light source enters the pixel P. In the pixel P, if a photoreaction occurs due to light incident on the interface between the alignment films 18 and 24 and the liquid crystal layer 50, the liquid crystal material may be deteriorated. The deterioration of the liquid crystal material in the photoreaction is treated as the light-resistant life of the liquid crystal device 100.

  Light incident on the liquid crystal panel 110 (the liquid crystal device 100) from the counter substrate 20 side is reflected by the pixel electrode 15 having reflectivity. When the light incident on the pixel electrode 15 is referred to as incident light and the light reflected by the pixel electrode 15 is referred to as reflected light, the incident light and the reflected light interfere with each other near the surface of the pixel electrode 15 to form a sinusoidal constant. A standing wave S is generated.

  FIG. 5 is a graph showing the power density of the standing wave S generated near the pixel electrode of the element substrate shown in FIG. The vertical axis in the graph of FIG. 5 is a value obtained by calculating the power density of the standing wave S by the FDTD (Finite-difference time-domain method) method, and the horizontal axis is the pixel electrode in the Z direction orthogonal to the X direction and the Y direction. The coordinates z (nm) indicate a position where the position of the surface of No. 15 is 0 nm and the direction from the surface toward the counter substrate 20 is positive.

  As shown in FIG. 5, the power density (Power Density; PD) is minimal at a portion corresponding to the node S1 of the standing wave S, and is maximal at a portion corresponding to the antinode S2 of the standing wave S. Therefore, when the antinode S2 of the standing wave S is located at the interface between the alignment film 18 which is an inorganic alignment film and the liquid crystal layer 50 shown in FIG. In addition, a photoreaction easily occurs in the liquid crystal material. In other words, if the antinode S2 of the standing wave S is not located at the interface between the alignment film 18 and the liquid crystal layer 50, a photoreaction does not easily occur in the liquid crystal material. Note that the light incident on the pixel electrode 15 is reflected after penetrating to a predetermined depth from the surface of the pixel electrode 15, so that the end S 0 of the standing wave S is located at a position at a predetermined depth from the surface of the pixel electrode 15. And the power density at the end S0 of the standing wave S is “0”.

  As shown in FIG. 4, since the alignment film 18 is an aggregate of columnar bodies 18 a obtained by obliquely depositing an inorganic material such as silicon oxide, the alignment film 18 has porosity. An interface between the alignment film 18 and the liquid crystal layer 50 exists in the entire thickness direction of the film 18.

Therefore, first, a condition in which the node S1 of the standing wave S is located near the center in the thickness direction (Z direction) of the alignment film 18 will be examined. Specifically, the center wavelength of incident light incident from the counter substrate 20 side is λ (nm), the refractive index of the first insulating film 16 is n ₁ , the film thickness is d _1, and the refractive index of the alignment film 18 is n ₂ and the film thickness are d ₂ . Further, assuming that the penetration depth of the incident light into the pixel electrode 15 is δ (nm) and the refractive index of the pixel electrode 15 is nt, the node S1 of the standing wave S becomes an alignment film if the following expression (1) is satisfied. 18 is located near the center in the thickness direction.
_{mλ / 2 = ntδ + n 1} d 1 + (n 2 d 2/2) ··· (1)
m is a positive integer of 1 or more, and the left side of the above equation (1) is an integer multiple of the length λ / 2 from the node S1 to the node S1 of the standing wave S. The right side of the above equation (1) indicates an optical distance (optical path length) D from the substantial reflection surface of the incident light on the pixel electrode 15 to the center of the alignment film 18 in the thickness direction. The optical distance D is given by the sum of the product of the refractive index and the thickness of each layer through which light passes. Since the standing wave S is generated by the incident light and the reflected light, the wavelength of the standing wave S is the same as the wavelength λ of the incident light in the same medium through which the light passes. The thickness d ₁ of the first insulating film 16, the thickness d ₂ of the alignment film 18 is, for example, can be confirmed accurately by observing the cross section of the element substrate 10 with a scanning electron microscope (SEM) It is.

  The penetration depth δ of the incident light into the pixel electrode 15 is determined by setting the electrical resistivity of the pixel electrode 15 to ρ [Ωm], setting the absolute magnetic permeability to μ [H / m; Henry per meter], and setting the angular frequency of the photoelectric field to ω. If [rad / sec; radians per second] is given by the following equation (2).

なお、角周波数ω［ｒａｄ／ｓｅｃ］は、ω＝２πｃ／λで与えられる。ｃは真空中の光の速度［ｍ／ｓｅｃ；メートル毎秒］である。

Note that the angular frequency ω [rad / sec] is given by ω = 2πc / λ. c is the speed of light in a vacuum [m / sec; meter per second].

When, for example, Al (aluminum) is used as a material forming the pixel electrode 15, the penetration depth δ is approximately 3.17 nm according to the above equation (2). When Ag (silver) is used, it is about 2.46 nm, and when Ni (nickel) is used, it is about 0.21 nm. On the other hand, the thicknesses of the first insulating film 16 and the alignment film 18 covering the pixel electrode 15 are each 50 nm or more in consideration of the electrical characteristics of the liquid crystal device 100, the alignment of liquid crystal molecules, the film forming property, and the like. Is required. Therefore, the value of the penetration depth δ of the incident light penetrating from the surface of the pixel electrode 15 is smaller than the film thickness of the first insulating film 16 and the alignment film 18, so that the above-described optical distance (optical path length) D The relationship between the refractive index nt of the pixel electrode 15 and the refractive index n ₁ of the first insulating film 16 in the mathematical expression (1) for obtaining can be regarded as nt = n ₁ . Further, by forming the first insulating film 16 and the alignment film 18 both the same material, the relationship between the refractive index n ₂ of the refractive index n ₁ and the orientation film 18 of the first insulating film 16, n ₁ = n ₂ Therefore, the above equation (1) can be changed to the following equation (3).
_{D = mλ / 2 = n 1} (δ + d 1 + d 2/2) ··· (3)
_{δ + d 1 + d 2/} 2 is the distance d from the substantial reflecting surface of the pixel electrode 15 in the Z direction until the thickness direction center of the alignment film 18.

From the viewpoint of suppressing the deterioration of the liquid crystal material due to the photoreaction at the interface between the alignment film 18 and the liquid crystal layer 50, the node S1 of the standing wave S is located near the center in the thickness direction (Z direction) of the alignment film 18. However, since it is difficult to position the optical distance strictly near the center, it is preferable that the following formula (4) is satisfied when the allowable range of the optical distance (optical path length) D is examined.
(Mλ / 2) − (λ / 8) <D <(mλ / 2) + (λ / 8) (4)
λ / 8 is an optical distance between a node S1 at which the power density of the standing wave S is minimum and an inflection point S3 at which the power density is halfway between the minimum and maximum. When the allowable range of the optical distance D defined by the above equation (4) is replaced with the allowable range of the distance d from the surface of the pixel electrode 15 in the Z direction to the center of the alignment film 18 in the thickness direction, the following equation is obtained. (5) is derived.

  That is, assuming that a positive integer indicating the number of the node of the standing wave S is m, the distance d from the surface of the pixel electrode 15 in the Z direction to the center in the thickness direction of the alignment film 18 is expressed by the above equation (5 ), The inflection point S3 closest to the node S1 of the standing wave S as indicated by arrows M1, M2, M3,... In FIG. The vicinity of the center of the alignment film 18 in the thickness direction, that is, the interface between the alignment film 18 and the liquid crystal layer 50 is located within the allowable range up to.

For example, when m is set to a minimum of 1, the wavelength λ of the incident light is set to 450 nm, the penetration depth δ is set to 3 nm, and the refractive index n ₁ of the first insulating film 16 is set to 1.43, the above equation (5) is used. , The allowable range of the distance d is 115 nm <d <193 nm.

By making the film thickness of the alignment film 18 smaller than λ / 4n ₂ , not only the center in the thickness direction of the alignment film 18 but also the position of the standing wave S where the power density PD is maximized at a position deviated from the center. It is considered that the position of the belly S2 can be avoided. For example, if λ is 450 nm and the refractive index n ₂ is 1.43, the preferred thickness of the alignment film 18 is about 79 nm.

  On the other hand, actually, the positional relationship between the antinode S2 of the standing wave S and the interface between the alignment film 18 and the liquid crystal layer 50 is not only a variation in the thickness of the alignment film 18 but also a variation in the thickness of the first insulating film 16. It is also affected by variations. That is, the light-proof life of the liquid crystal device 100 varies. Therefore, even if there is variation in the thickness of the first insulating film 16 and variation in the thickness of the alignment film 18, it is hardly affected by the antinode S2 of the standing wave S having the maximum power density. The structure of the element substrate 10 capable of suppressing the variation was studied.

  FIG. 6 is a schematic plan view illustrating a planar configuration of a pixel in the liquid crystal device according to the first embodiment, and FIG. 7 is a schematic cross-sectional view illustrating a pixel structure along line A-A ′ in FIG. Note that the line A-A ′ in FIG. 6 is a line segment that crosses the pixel P in the Y direction. In FIG. 7, the details of the wiring layers 11, 12, 13, and 14 in the element substrate 10 are omitted.

  As shown in FIG. 6, the pixel P has a first region P (A) having a different optical distance D from the substantial reflection surface of the pixel electrode 15 in the Z direction to the center in the thickness direction of the alignment film 18. And a second region P (B). The planar shape of the pixel P (pixel electrode 15) in the present embodiment is a square. The first area P (A) and the second area P (B) are obtained by dividing the pixel P into two in the Y direction, and each have a rectangular shape long in the X direction. In other words, the area ratio of the first region P (A) and the area ratio of the second region P (B) with respect to the area of the pixel P are the same, each being ２.

  The alignment of the liquid crystal molecules LC in the liquid crystal layer 50 of the liquid crystal device 100 of the present embodiment is substantially vertical alignment (VA) as described above, and the direction of the pretilt of the liquid crystal molecules LC passes through the center of the pixel P, for example. The arrow AO intersects a line segment (indicated by a dashed line in FIG. 6) extending in the Y direction at an angle θa. Such a state of substantially vertical alignment is called uniaxial VA alignment. The angle θa in the uniaxial VA alignment of this embodiment is 45 degrees, and the direction of the pretilt of the liquid crystal molecules LC is, for example, a direction from the lower left corner to the upper right corner of the pixel P shown in FIG. . The direction of the pretilt of the liquid crystal molecules LC may be a direction from the upper right corner to the lower left corner. Further, the direction of the pretilt of the liquid crystal molecules LC is not limited to this, and the direction from the upper left corner to the lower right corner or the lower right corner to the upper left corner of the pixel P shown in FIG. Direction. Therefore, in FIG. 6, the arrow AO indicating the direction of the pretilt in the uniaxial VA orientation is indicated by a double-ended arrow.

  In such a uniaxial VA orientation, the vibration direction PL of the electric field of the incident light, which is polarized light for maximizing the contrast, is the X direction in this case. The vibration direction PL of the electric field of the incident light is defined by a polarizing element arranged on the light incident side of the liquid crystal panel 110. Note that the vibration direction PL of the electric field of the incident light may be the Y direction orthogonal to the X direction.

  The pixel P has the first region P (A) and the second region P (B) having different optical distances D as described above. From the viewpoint of suppressing the occurrence of a difference in contrast at the boundary between the first area P (A) and the second area P (B) having different optical distances D, the first area P (A) The boundary of the second region P (B) is preferably parallel or perpendicular to the vibration direction PL of the electric field of the incident light.

  At the boundary between the first region P (A) and the second region P (B), a contact hole CNT5 for electrically connecting the pixel electrode 15 and the TFT 30 is provided. The planar shape of the contact hole CNT5 is a rectangle long in the X direction. The contact hole CNT5 is arranged such that the center of the pixel P matches the center of the contact hole CNT5. Note that the position of the contact hole CNT5 is not limited to the center of the pixel P, but a rectangular contact hole CNT5 in plan view is formed by the first region P (A) and the second region P (B ), The decrease in contrast due to the disorder of the alignment of the liquid crystal molecules LC in the contact hole CNT5 also becomes less noticeable.

  As shown in FIG. 7, the incident light L that has entered the first region P (A) of the pixel P passes through the alignment film 18 and the first insulating film 16 in the element substrate 10 and enters the pixel electrode 15. And reflected to become reflected light Lr. The penetration depth of the incident light L at the pixel electrode 15 is δ, and a substantial reflection surface exists at a position advanced from the surface of the pixel electrode 15 by the penetration depth δ. The substantial position of the reflective surface of the pixel electrode 15 is the same in the second region P (B).

  In the first region P (A) and the second region P (B) of the pixel P, the film thickness of the pixel electrode 15 is made different from the substantial reflection surface of the pixel electrode 15 in the Z direction to make the alignment film. The optical distance D to the center in the thickness direction of 18 is different. Specifically, the thickness of the pixel electrode 15 in the first region P (A) is larger (thicker) than the thickness of the pixel electrode 15 in the second region P (B). Hereinafter, the optical distance of the first area P (A) is referred to as D (A), and the optical distance of the second area P (B) is referred to as D (B).

  The first insulating film 16 covering the pixel electrode 15 is subjected to a flattening process so that the step due to the difference in the thickness of the pixel electrode 15 in the pixel P is not reflected on the surface of the alignment film 18 and is in a flat state. Is given. Thereby, the thickness of the first insulating film 16 formed between the pixel electrode 15 and the alignment film 18 is smaller in the first region P (A) than in the second region P (B) ( Thin). That is, the distance d (A) from the surface of the pixel electrode 15 in the first region P (A) to the center of the alignment film 18 is equal to the distance d (A) from the surface of the pixel electrode 15 in the second region P (B) to the alignment film 18. It is smaller than the distance d (B) to the center, and d (A) <d (B). Therefore, the optical distance D (A) of the first area P (A) is smaller than the optical distance D (B) of the second area P (B), and D (A) <D (B). It has become.

  Since the thickness of the pixel electrode 15 is different between the first region P (A) and the second region P (B), the boundary between the first region P (A) and the second region P (B). In the portion, a slope 15 c is formed on the pixel electrode 15. The slope 15c extends in the X direction along the boundary. Since the surface of the alignment film 18 above the boundary is also flat, the slope 15c of the pixel electrode 15 does not affect the alignment of the liquid crystal molecules LC. Even if the incident light L is incident on such a slope 15c and the reflected light Lr proceeds in a direction different from the incident direction, the above-mentioned boundary portion is in the vibration direction PL of the electric field of the incident light L as shown in FIG. , The decrease in contrast at the boundary is hardly noticeable. Specifically, the pixel electrode 15 forms the inclined surface 15c at the boundary, and the angle formed by the boundary and the vibration direction PL of the electric field of the incident light L is either 0 degree (parallel) or 90 degrees (vertical). In this case, the vibration direction of the electric field of the incident light L and the reflected light Lr becomes the same, so that the contrast does not decrease. Note that the contrast refers to a contrast in a case where the liquid crystal molecules LC in the liquid crystal layer 50 are uniaxial VA alignment and black display is performed when no voltage is applied.

The power density (PD) of the standing wave S shown in FIG. 5 can be approximated to a sine wave when m is 1 or more. Hereinafter, a sine wave approximating the power density (PD) of the standing wave S is formulated. From the above equation (5), since the distance d at which PD = 0 is d = mλ / 2n ₁ −δ, the period T of the sine wave (the distance between the valleys in the power density of the standing wave S) Becomes the following equation (6).
T = λ / 2n ₁ (6)

The angular frequency ω of the sine wave is ω = 2π / T. When the amplitude of the sine wave is A and the initial phase is φ, the following equation (7) is derived.
PD = (A / 2) sin (2πz / T−φ) + A / 2 (7)
z is the distance from the surface of the pixel electrode 15.

Since the power density PD of the standing wave S is PD = 0 on the reflection surface that has advanced from the surface of the pixel electrode 15 by the penetration depth δ, the following equation can be obtained by substituting φ = 2πδ / T into the above equation (7). (8) is derived.
PD = (A / 2) sin (2πz / T−2πδ / T) + A / 2
= (A / 2) sin [2π / T (z-δ)] + A / 2 (8)

When the above equation (6) is substituted into the above equation (8), the following equation (9) is derived.
PD = (A / 2) sin [4n ₁ π (z−δ) / λ] + A / 2 (9)

FIG. 8 is a graph in which the power density (PD) of the standing wave S is approximated to a sine wave under a predetermined condition.
For example, when A = 2, n ₁ = 1.43, λ = 450 nm, and δ = 3.17 and applied to the above equation (9), the power density (PD) of the standing wave S shown in FIG. As shown in (1), the average value of the power density (PD) can be approximated to a sine wave standardized as “1”.

  Next, the power density (PD) of the standing wave S in the pixel P of the present embodiment is determined by applying the above equation (9). Specifically, the power density of the standing wave S in the first region P (A) is PD (A), and the power density of the standing wave S in the second region P (B) is PD (B). , The average value of the power density PD of the standing wave S in the pixel P is PD (AB).

When the power density PD (A) of the standing wave S in the first area P (A) is applied to the above equation (9) to obtain the following equation (10), the standing wave in the second area P (B) is obtained. The power density PD (B) of S is represented by the following equation (11), and the average value PD (AB) of the power density of the standing wave S of the pixel P is represented by the following equation (12).
PD (A) = (A / 2) sin [4n ₁ π (z−δ) / λ] + A / 2 (10)
PD (B) = (A / 2) sin [4n ₁ π (z + Δd−δ) / λ] + A / 2 (11)
2PD (AB) = (A / 2) sin [4n 1 π (z-δ) / λ] + (A / 2) sin [4n 1 π (z + Δd-δ) / λ] + A ··· (12)
Δd = d (B) −d (A), which corresponds to the difference in the thickness of the pixel electrode 15 between the first region P (A) and the second region P (B).

FIG. 9 is a graph showing the power densities PD (A), PD (B), and PD (AB) of the standing wave S when Δd is 0.25λ / n ₁ .
Since T = λ / 2n ₁ as shown in the above equation (6), if Δd = 0.25λ / n ₁ as shown in FIG. 9, then Δd = 0.5T. Accordingly, a sine wave indicating the power density PD (A) of the standing wave S in the first area P (A) and a power density PD (B) of the standing wave S in the second area P (B) are illustrated. In the case of a sine wave, the phase is shifted by 周期 cycle, and when one is maximum, the other is minimum. Therefore, the power density PD of the standing wave S in the pixel P, that is, the average value of the power density. PD (AB) is a standardized value “1”. That is, the power density PD of the standing wave S in the pixel P is averaged. At this time, the optical distance D (A) from the substantial reflection surface of the pixel electrode 15 in the first region P (A) to the center in the thickness direction of the alignment film 18 and the second region P (B The difference ΔD from the optical distance D (B) from the substantial reflection surface of the pixel electrode 15 to the center in the thickness direction of the alignment film 18 is ΔD = n ₁ Δd = 0.25λ.

  That is, the film thickness of the pixel electrode 15 is set so that the difference ΔD between the optical distances D (A) and D (B) becomes 0.25λ by the first region P (A) and the second region P ( B), the variation in the deterioration of the liquid crystal material due to the photoreaction of the standing wave S is suppressed even if the thicknesses of the first insulating film 16 and the alignment film 18 vary.

  As a method of forming the pixel electrode 15 by precisely varying the film thickness between the first region P (A) and the second region P (B) so that the difference ΔD = 0.25λ, When patterning the electrode 15, a method of forming a multi-stage resist layer using a halftone mask and performing dry etching to etch the electrode film (in this case, a reflective metal film such as Al) is used.

Since varying the thickness of the pixel electrode 15 between the first region P (A) and the second region P (B) also involves variation, the allowable range of the difference ΔD will be examined. More specifically, it sets the patterning accuracy of the pixel electrode 15, and about 10% ± the value of Δd with respect to 0.25λ / n _1. Then, 0.225λ / n ₁ ≦ Δd ≦ 0.275λ / n ₁ holds. The difference ΔD between the optical distances D is 0.225λ ≦ ΔD ≦ 0.275λ. That is, the allowable range defined by the wavelength λ of the incident light does not depend on the refractive index n ₁ of the first insulating film 16.

FIG. 10 is a graph showing the power densities PD (A), PD (B), and PD (AB) of the standing wave S when Δd is 0.225λ / n _1, and FIG. 11 is a graph showing Δd at 0.275λ. 6 is a graph showing the power densities PD (A), PD (B), and PD (AB) of the standing wave S when / n ₁ is set.
As shown in FIGS. 10 and 11, the allowable range of the difference ΔD of the optical distance D between the first region P (A) and the second region P (B) is 0.225λ ≦ ΔD ≦ 0. .275λ, the power density PD (AB) of the standing wave S in the pixel P falls within a range of about ± 15% on the average of the normalized “1”. In other words, the influence of the variation in the thickness of the first insulating film 16 and the alignment film 18 is eliminated, and the standing wave S causes a photoreaction at the interface between the alignment film 18 and the liquid crystal layer 50, thereby deteriorating the liquid crystal material. Variation can be suppressed.

According to the first embodiment, the following effects can be obtained.
(1) The optical distance between the substantial reflection surface of the pixel electrode 15 and the center in the thickness direction of the alignment film 18 in the first region P (A) and the second region P (B) of the pixel P D, the standing wave S generated by the interference between the light incident on the pixel electrode 15 and the light reflected by the pixel electrode 15 in the first region P (A) and the second region P (B). Have different phases. Therefore, in the pixel P, the antinode S2 of the standing wave S is less likely to be located near the interface between the liquid crystal layer 50 and the alignment film 18. Therefore, even if the film thickness of the first insulating film 16 or the alignment film 18 related to the optical distance D between the substantial reflection surface of the pixel electrode 15 and the center in the thickness direction of the alignment film 18 is constant, Deterioration of the liquid crystal material due to the presence of the wave S becomes difficult to progress, and variation in deterioration of the liquid crystal material due to a photoreaction can be suppressed.

  (2) Since the area ratio of the first region P (A) and the area ratio of the second region P (B) to the opening area of the pixel P are the same, the antinode S2 of the standing wave S is A state in which it is difficult to be located near the interface between the alignment film 18 and the liquid crystal layer 50 can be homogenized for each pixel P. Therefore, variation in deterioration of the liquid crystal material due to a photoreaction can be further suppressed.

  (3) The pixel electrode 15 is adjusted so that the difference ΔD in the optical distance D between the first region P (A) and the second region P (B) satisfies 0.225λ ≦ ΔD ≦ 0.275λ. Since the film thickness is controlled, the variation of the power density PD of the standing wave S generated near the surface of the pixel electrode 15 of the pixel P is within a range of about ± 15%. That is, the light-proof life of the liquid crystal device 100 (the liquid crystal panel 110) can be kept within a predetermined range of variation.

  (4) The thickness of the pixel electrode 15 is controlled so that the difference ΔD in the optical distance D between the first region P (A) and the second region P (B) satisfies ΔD = 0.25λ. Then, even if the power density PD (A) of the standing wave S in the first area P (A) is maximized, the power density PD (B) of the standing wave S is increased in the second area P (B). Minimize. In other words, since the power density PD of the standing wave S in the pixel P can be averaged and reduced, variation in deterioration of the liquid crystal material due to photoreaction can be further suppressed.

  (5) In the first region P (A) and the second region P (B), the thickness of the pixel electrode 15 is made different, and the first insulating film 16 covering the pixel electrode is subjected to a flattening process. , The optical distance D differs. Therefore, the configuration is such that the slope 15c, which is the step portion of the pixel electrode 15 due to the difference in film thickness, is not reflected on the alignment film 18 via the first insulating film 16. Therefore, it is possible to prevent the inclined surface 15c, which is the step portion of the pixel electrode 15, from affecting the alignment film 18 and causing the disorder of the alignment of the liquid crystal molecules.

  (6) The boundary between the first area P (A) and the second area P (B) is parallel or perpendicular to the vibration direction PL of the electric field of the incident light. Therefore, the boundary between the first region P (A) and the second region (B) having different optical distances D obliquely intersects the vibration direction PL of the electric field of the incident light. It is possible to suppress a decrease in contrast in the portion.

  (7) The contact hole CNT5 as a contact portion for electrically connecting the pixel electrode 15 and the TFT 30 is provided at the boundary between the first region P (A) and the second region P (B). . Even if the surface of the pixel electrode 15 has irregularities due to the provision of the contact holes CNT5, the decrease in contrast due to the irregularities is less noticeable because the irregularities overlap the boundary portion in plan view.

(2nd Embodiment)
Next, a liquid crystal device according to a second embodiment will be described with reference to FIG. FIG. 12 is a schematic sectional view showing the structure of a pixel in the liquid crystal device according to the second embodiment. The liquid crystal device according to the second embodiment differs from the liquid crystal device 100 according to the first embodiment in that the optical distance D between the first region P (A) and the second region P (B) is different. Was changed. Therefore, the same components as those of the liquid crystal device 100 according to the first embodiment are denoted by the same reference numerals, and detailed description is omitted. FIG. 12 is a schematic cross-sectional view taken along the line AA ′ of FIG. 6 similarly to FIG. 7 used in the first embodiment.

  As shown in FIG. 12, the liquid crystal device 200 of the present embodiment includes a liquid crystal panel 210 having a liquid crystal layer 50 sandwiched between an element substrate 10B and a counter substrate 20. The alignment film 18 is formed on the liquid crystal layer 50 side of the element substrate 10B, and the alignment film 24 is formed on the liquid crystal layer 50 side of the counter substrate 20. The alignment films 18 and 24 are an aggregate of columnar bodies obtained by obliquely depositing an inorganic material such as silicon oxide.

  The pixel P of the liquid crystal panel 210 is provided with a first region P (A) and a second region P (B). In the element substrate 10B, the thickness of the first insulating film 16 between the reflective pixel electrode 15 and the alignment film 18 is made different between the first region P (A) and the second region P (B). Thus, the optical distance D between the substantial reflection surface of the pixel electrode 15 and the center in the thickness direction of the alignment film 18 is made different. Specifically, the thickness of the first insulating film 16 in the first region P (A) is smaller (thinner) than the thickness of the first insulating film 16 in the second region P (B).

  The distance d (A) from the surface of the pixel electrode 15 in the first region P (A) to the center in the thickness direction of the alignment film 18 is equal to the distance d (A) from the surface of the pixel electrode 15 in the second region P (B). Is smaller (shorter) than the distance d (B) to the center in the thickness direction. The incident light L is reflected after penetrating from the surface of the pixel electrode 15 to the penetration depth δ. In other words, the substantial reflection surface of the pixel electrode 15 is located at a position where the pixel electrode 15 enters from the surface to the inside with a penetration depth δ. Therefore, the relationship between the optical distance D (A) of the first area P (A) and the optical distance D (B) of the second area P (B) in the present embodiment is D (A). <D (B).

  At the boundary between the first region P (A) and the second region P (B), a slope 16c is formed in the first insulating film 16 due to the difference in film thickness. Since the alignment film 18 is formed on the first insulating film 16, the alignment film 18 also has a slope 18 c at a position corresponding to the slope 16 c of the first insulating film 16. The slope 18c of the alignment film 18 extends in the X direction along the boundary between the first region P (A) and the second region P (B). Therefore, since the boundary is parallel to the vibration direction PL of the electric field of the incident light, even if the alignment film 18 has the inclined surface 18c due to the inclined surface 16c of the first insulating film 16, the liquid crystal on the inclined surface 18c The decrease in contrast due to disorder in the orientation of molecules is less noticeable.

  The first insulating film 16 is formed such that a difference ΔD in an optical distance D between the first region P (A) and the second region P (B) satisfies 0.225λ ≦ ΔD ≦ 0.275λ. The thickness is controlled. The thickness of the first insulating film 16 is set such that the difference ΔD in the optical distance D between the first region P (A) and the second region P (B) is ΔD = 0.25λ. It is preferable to control.

According to the liquid crystal device 200 of the second embodiment, the following effects are obtained in addition to the effects (1), (2), (6), and (7) of the liquid crystal device 100 of the first embodiment. .
(8) The first insulating film so that the difference ΔD of the optical distance D between the first region P (A) and the second region P (B) satisfies 0.225λ ≦ ΔD ≦ 0.275λ. Since the film thickness of the pixel 16 is controlled, the variation of the power density PD of the standing wave S generated near the surface of the pixel electrode 15 of the pixel P is in the range of about ± 15%, as in the first embodiment. Become. That is, the light-proof life of the liquid crystal device 200 (the liquid crystal panel 210) can be kept within a predetermined range of variation. In addition, at the boundary between the first region P (A) and the second region P (B), the pixel electrode 15 does not have the slope 15c as the stepped portion as in the first embodiment, so The traveling direction of the reflected light Lr does not vary at the boundary between the first area P (A) and the second area P (B). That is, at the boundary portion, the contrast does not decrease due to the variation in the traveling direction of the reflected light Lr.

  (9) The thickness of the first insulating film 16 is set so that the difference ΔD in the optical distance D between the first region P (A) and the second region P (B) satisfies ΔD = 0.25λ. Is controlled, the power density PD (A) of the standing wave S in the second region P (B) is maximized even if the power density PD (A) of the standing wave S in the first region P (A) is maximized. ) Is minimized. In other words, since the power density PD of the standing wave S in the pixel P can be averaged and reduced, variation in deterioration of the liquid crystal material due to photoreaction can be further suppressed.

(Third embodiment)
<Electronic equipment>
Next, the electronic apparatus of the present embodiment will be described with reference to FIG. 13 using a projection display device as an example. FIG. 13 is a schematic diagram illustrating a configuration of a three-panel reflective liquid crystal projector that is an example of a projection display device as an electronic apparatus.

As shown in FIG. 13, the liquid crystal projector 1000 is a projection type display device of this embodiment, the polarizing illumination device 1100 is disposed along a system optical axis L _0, three as a color separating means of the dichroic mirror 1111, 1112, 1115, two reflection mirrors 1113, 1114, reflection type liquid crystal light valves 1250, 1260, 1270 as three light modulating means, and light modulated by each of the three light modulating means. A cross dichroic prism 1206 as a light combining means for forming display light and a projection lens 1207 are provided.

  The polarized light illuminating device 1100 is roughly composed of a lamp unit 1101 as a light source composed of a white light source such as an ultra-high pressure mercury lamp and a halogen lamp, an integrator lens 1102, and a polarization conversion element 1103.

  The polarized luminous flux emitted from the polarized light illuminating device 1100 enters the dichroic mirror 1111 and the dichroic mirror 1112 arranged orthogonally to each other. The dichroic mirror 1111 as a color separating unit reflects red light (R) of the incident polarized light beam. A dichroic mirror 1112 as another color separation unit reflects green light (G) and blue light (B) in the incident polarized light beam.

  The reflected red light (R) is reflected again by the reflection mirror 1113 and enters the liquid crystal light valve 1250 as the first light modulation unit. On the other hand, the reflected green light (G) and blue light (B) are reflected again by the reflection mirror 1114 and enter a dichroic mirror 1115 as color separation means. The dichroic mirror 1115 reflects green light (G) and transmits blue light (B). The reflected green light (G) enters a liquid crystal light valve 1260 as a second light modulation unit. The transmitted blue light (B) enters a liquid crystal light valve 1270 as a third light modulation unit.

  In the present embodiment, a configuration including the polarized illumination device 1100 and three dichroic mirrors 1111, 1112, and 1115 is an example of the illumination device according to the invention.

The liquid crystal light valve 1250 includes a reflective liquid crystal panel 1251 and a wire grid type polarizer 1253 that is a reflective polarizer.
The liquid crystal light valve 1250 is arranged such that the red light (R) reflected by the polarizing element 1253 is perpendicularly incident on the incident surface of the cross dichroic prism 1206. Further, an auxiliary polarizing element 1254 for compensating for the degree of polarization of the polarizing element 1253 is arranged on the incident side of the red light (R) in the liquid crystal light valve 1250, and another auxiliary polarizing element 1255 is provided on the emitting side of the red light (R). It is arranged along the incident surface of the dichroic prism 1206. When a polarizing beam splitter is used as the reflective polarizing element, the pair of auxiliary polarizing elements 1254 and 1255 can be omitted.
The configuration of such a reflective liquid crystal light valve 1250 and the arrangement of each component are the same in the other reflective liquid crystal light valves 1260 and 1270.

  The respective color lights incident on the liquid crystal light valves 1250, 1260, 1270 are modulated based on the image information, and again enter the cross dichroic prism 1206 via the wire grid type polarizing elements 1253, 1263, 1273. In the cross dichroic prism 1206, the respective color lights are combined, and the combined display light is projected on the screen 1300 by the projection lens 1207, and the image is enlarged and displayed.

  In the present embodiment, the liquid crystal device 100 of the first embodiment is applied as the liquid crystal light valves 1250, 1260, 1270. On the light incident side of the liquid crystal device 100 as the liquid crystal light valve 1250, a wire grid type polarizing element 1253 is arranged in a state inclined at an angle of 45 degrees with respect to the optical axis. The same applies to other wire grid type polarizing elements 1263, 1273.

  The green light (G) modulated by the liquid crystal light valve 1260 goes straight to the cross dichroic prism 1206, and the red light (R) modulated by the liquid crystal light valve 1250 and the green light (R) modulated by the liquid crystal light valve 1270. The left and right sides of the image are reflected by the dielectric multilayer film with respect to the blue light (B). Therefore, the optical conditions are set corresponding to the colored light so that the combined light does not cause coloring due to the viewing angle characteristics of each of the liquid crystal light valves 1250, 1260, and 1270. Specifically, with respect to the direction of the pretilt of the liquid crystal molecules in the liquid crystal panel 1261 for the green light (G), the liquid crystal molecules 1251 for the liquid crystal panel 1251 for the other red light (R) and the liquid crystal panel 1271 for the blue light (B). The inorganic orientation film is formed by inverting the planar deposition direction of the oblique deposition by 180 ° so that the pretilt direction is reversed.

  According to such a liquid crystal projector 1000, the liquid crystal device 100 is applied to the reflection type liquid crystal light valves 1250, 1260, 1270 provided for each color light, and the reflection type liquid crystal light valves 1250, 1260, and 1270 correspond to the wavelength of the color light incident on the liquid crystal panel 110. Thus, the optics from the substantially reflective surface of the pixel electrode 15 in the first region P (A) and the second region P (B) of the pixel P to the center in the thickness direction of the alignment film 18 which is an inorganic alignment film. Distance D is different. Therefore, it is possible to provide the reflection-type liquid crystal projector 1000 capable of suppressing variations in light-proof life and obtaining a good-looking display state.

  Since the deterioration of the liquid crystal material due to the photoreaction is considered to progress more easily as the wavelength of the light is shorter, the liquid crystal device 100 of the above embodiment is connected to at least the liquid crystal light valve 1270 as the third light modulator into which the blue light is incident. By applying the present invention, it is possible to provide the reflection-type liquid crystal projector 1000 in which the variation in the light-proof life is suppressed. Similar effects can be obtained by using the liquid crystal device 200 of the second embodiment as the liquid crystal light valves 1250, 1260, 1270.

  In the present embodiment, the white light (polarized light flux) emitted from the polarized light illuminating device 1100 is separated into each color light by a dichroic mirror and is incident on the liquid crystal light valves 1250, 1260, 1270. Not done. As a lighting device capable of emitting three colors of light, for example, a solid-state light source such as a laser light source or an LED that can emit light of each color may be used. This can eliminate the need for a color separation unit.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or spirit of the invention which can be read from the claims and the entire specification, and a reflective liquid crystal with such a change. The device and electronic equipment to which the reflection type liquid crystal device is applied are also included in the technical scope of the present invention. Various modifications other than the above embodiment are conceivable. Hereinafter, a description will be given with a modification.

(Modification 1) In the pixel P, a plurality of regions having different optical distances D from the substantial reflection surface of the pixel electrode 15 to the center in the thickness direction of the alignment film 18 are different from the first region P (A). The present invention is not limited to the two second regions P (B). FIGS. 14 to 16 are schematic plan views showing the arrangement of a plurality of regions having different optical distances D in the pixels P of the modified example.
For example, as shown in FIG. 14, the pixel P may be divided into four parts in the Y direction in plan view, and the first regions P (A) and the second regions P (B) may be arranged alternately.
Further, for example, as shown in FIG. 15, the pixel P is divided into four in the X direction and the Y direction in a plan view, for a total of 16 divisions. Then, the first regions P (A) and the second regions P (B) may be alternately arranged in the X direction and the Y direction. That is, the first area P (A) and the second area P (B) may be arranged in a checkered pattern in the pixel P.
Further, for example, as shown in FIG. 16, the pixel P is divided into four in the X direction and the Y direction in a plan view, for a total of 16 divisions. Then, the first region P (A) and the second region P (B) may be randomly arranged in the X direction and the Y direction. However, the number of the first regions P (A) is the same as the number of the second regions P (B).
In the modified examples shown in FIGS. 14 to 16, it is preferable that the area ratio of the first region P (A) to the opening area of the pixel P be the same as the area ratio of the second region P (B). Further, the form of division of the pixel P in a plan view is such that the boundary between the first region P (A) and the second region P (B) is parallel or perpendicular to the vibration direction PL of the electric field of the incident light. Is preferable from the viewpoint of suppressing a decrease in contrast at the boundary portion.

(Modification 2) The configuration in which the optical distance D from the substantial reflection surface of the pixel electrode 15 to the center in the thickness direction of the alignment film 18 in a plurality of regions of the pixel P is different from that of the first embodiment. The present invention is not limited to making the film thickness of the pixel electrode 15 different or changing the film thickness of the first insulating film 16 as in the second embodiment. FIG. 17 is a schematic sectional view showing the structure of a pixel of a liquid crystal device according to a modification. FIG. 17 corresponds to FIG. 7 used in the first embodiment, and shows the structure of a pixel according to a modification along the line AA ′ in FIG.
As shown in FIG. 17, a liquid crystal device 300 according to a modification includes a liquid crystal panel 310 having a liquid crystal layer 50 sandwiched between an element substrate 10C and a counter substrate 20. The element substrate 10C includes, in the pixel P, a first area P (A) and a second area P (A) in which the optical distance D from the substantial reflection surface of the pixel electrode 15 to the center in the thickness direction of the alignment film 18 is different. P (B). In the first region P (A), an insulating film 16a is provided between the pixel electrode 15 and the alignment film 18. In the second region P (B), an insulating film 16b is provided between the pixel electrode 15 and the alignment film 18. The thicknesses of the insulating films 16a and 16b are the same, but the constituent materials are different. For example, the insulating film 16a is made of silicon oxide (SiO ₂ ) and has a refractive index of, for example, 1.43. On the other hand, the insulating film 16b is made of silicon oxynitride (SiOxNy) and has a refractive index of, for example, 1.60. As described in the first embodiment, the optical distance D is obtained as the sum of the product of the refractive index and the thickness of each layer through which light passes. Therefore, even if the film thickness is the same, the optical distance D (A) of the first region P (A) and the optical distance D (A) of the second region P are changed by making the refractive indexes of the insulating films 16a and 16b different. The optical distance D (B) of (B) can be made different. In the present modification, no step is formed in the pixel electrode 15 or the alignment film 18 at the boundary between the first region P (A) and the second region P (B). That is, a decrease in contrast due to the step does not occur.

  (Modification 3) The electronic apparatus to which the liquid crystal device of each of the above embodiments is applied is not limited to the liquid crystal projector 1000. For example, the counter substrate 20 of the liquid crystal device 100 may include at least color filters corresponding to red (R), green (G), and blue (B), and the liquid crystal light valve may have a single-plate configuration. Further, for example, a projection type HUD (head-up display), an HMD (head mounted display), an electronic book, a personal computer, a digital still camera, a liquid crystal television, a viewfinder type or a monitor direct-view type video recorder, a car navigation system, The liquid crystal device 100 can be suitably used as a display unit of an information terminal device such as an electronic organizer and a POS. Similarly, the liquid crystal device 200 can be suitably used.

  Hereinafter, the contents derived from the above embodiment will be described.

  The liquid crystal device of the present invention includes a first substrate having a reflective first electrode, a first insulating film, and a first alignment film that is an oblique deposition film, and a light-transmitting second electrode and a first substrate that is an oblique deposition film. A second substrate having a two-alignment film, and a liquid crystal layer provided between the first substrate and the second substrate, wherein an optical path between the first electrode and a center of the first alignment film in a thickness direction is provided. A plurality of regions having different distances D are provided for each pixel.

  According to this configuration, since the optical distance D between the first electrode and the center in the thickness direction of the first alignment film in the plurality of regions of the pixel is different, light incident on the first electrode in the plurality of regions is different. And the phase of the standing wave generated by the interference with the light reflected by the first electrode. Therefore, in the pixel, it is difficult for the antinode of the standing wave to be located near the interface between the liquid crystal layer and the first alignment film. Therefore, even if the film thickness of the first insulating film or the first alignment film related to the optical distance D between the first electrode and the center of the first alignment film in the thickness direction fluctuates, the liquid crystal material due to the standing wave Of the liquid crystal material due to the photoreaction can be suppressed.

In the above liquid crystal device, the plurality of regions include a first region and a second region having different optical distances D, and an area ratio of the first region to an opening area of the pixel and a ratio of the second region to the opening area of the pixel. It is preferable that the area ratio is the same.
According to this configuration, the state in which the antinode of the standing wave is hardly located near the interface between the liquid crystal layer and the first alignment film can be homogenized for each pixel. Variation can be further suppressed.

In the above liquid crystal device, it is preferable that the difference ΔD between the optical distances D in the plurality of regions satisfies the following expression (1).
0.225λ ≦ ΔD ≦ 0.275λ (1)
(Λ is the wavelength of light incident on the first electrode)
According to this configuration, the difference ΔD between the optical distances D of the plurality of regions in the pixel is set such that the antinode of the standing wave is positioned near the interface between the liquid crystal layer and the first alignment film according to the wavelength of the incident light. It can be set to a predetermined range that makes it difficult.

In the above liquid crystal device, it is more preferable that the difference ΔD between the optical distances D in the plurality of regions satisfies the following expression (2).
ΔD = 0.25λ (2)
According to this configuration, the antinode of the standing wave is easily located near the interface between the liquid crystal layer and the first alignment film in one of the plurality of regions of the pixel, and the node of the standing wave in the other region. Are easily located near the interface between the liquid crystal layer and the first alignment film. Therefore, even if the light energy of the standing wave in one region is maximized, the light energy of the standing wave is minimized in the other region. That is, since it is possible to average and reduce the light energy of the standing wave in the pixel, it is possible to further suppress the variation in the deterioration of the liquid crystal material due to the photoreaction.

In the above-described liquid crystal device, the optical distance D is changed by changing the thickness of the first electrode in a plurality of regions.
According to this configuration, even if the first insulating film covering the first electrode is planarized, the optical distances D in the plurality of regions can be made different, so that the first film due to the different film thickness can be obtained. It is possible to adopt a configuration in which the step portion of one electrode is not reflected on the first alignment film via the first insulating film. Therefore, it is possible to prevent the step portion of the first electrode from affecting the first alignment film and causing the alignment of the liquid crystal molecules to be disturbed.

In the above liquid crystal device, the optical distance D may be changed by changing the thickness of the first insulating film in a plurality of regions.
According to this configuration, even if a step due to a difference in film thickness occurs in the first insulating film, the step does not affect the reflection of light on the first electrode. The optical characteristics, such as contrast and light use efficiency, are unlikely to vary due to the difference in the optical characteristics.

In the above-described liquid crystal device, it is preferable that a boundary between the plurality of regions is parallel or perpendicular to a vibration direction of an electric field of incident light.
According to this configuration, it is possible to suppress a decrease in contrast at the boundary, as compared with a case where the boundary between a plurality of regions having different optical distances D obliquely intersects the vibration direction of the electric field of the incident light. it can.

  In the above liquid crystal device, the boundary between the plurality of regions may be parallel or perpendicular to the vibration direction of the electric field of the incident light, and the first electrode may be inclined at the boundary between the plurality of regions. preferable.

In the above liquid crystal device, the boundary between the plurality of regions is parallel or perpendicular to the vibration direction of the electric field of the incident light, and the first insulating film has a slope at the boundary between the plurality of regions. Is preferred.
According to these configurations, a sharp decrease in contrast at the boundary can be suppressed.

In the above liquid crystal device, a transistor as a switching element is provided for each pixel, and a contact portion for electrically connecting the transistor and the first electrode overlaps with a boundary portion of a plurality of regions in plan view. preferable.
According to this configuration, even if unevenness occurs on the surface of the first electrode by providing a contact portion for electrically connecting the transistor and the first electrode, the unevenness is in plan view with the boundary between the plurality of regions. Because of the overlap, the decrease in contrast due to the unevenness becomes less noticeable.

  According to another aspect of the invention, there is provided an electronic apparatus including the above-described liquid crystal device.

  According to this configuration, it is possible to provide an electronic device in which variation in deterioration of a liquid crystal material due to a photoreaction, that is, variation in light resistance life is suppressed.

  The projection type display device of the present application is a lighting device that can emit three color lights, a first light modulation unit that modulates red light among three color lights, and a second light modulation that modulates green light among three color lights. Means, third light modulating means for modulating blue light of the three color lights, and light modulated by each of the first light modulating means, second light modulating means, and third light modulating means, and display light. And a projection lens for projecting display light. The liquid crystal device of the present application is provided in at least the third light modulating means among the first light modulating means, the second light modulating means, and the third light modulating means. It is characterized by being used.

  According to this configuration, the deterioration of the liquid crystal material due to the photoreaction is considered to proceed more easily as the wavelength of the light is shorter. Therefore, by applying the liquid crystal device of the present application to at least the third light modulating unit to which blue light is incident, It is possible to provide a projection display device in which variation in deterioration of a liquid crystal material due to photoreaction, that is, variation in light resistance life is suppressed.

  10: Element substrate as first substrate, 15: Pixel electrode as reflective first electrode, 15c: Slope of pixel electrode as first electrode, 16: First insulating film, 16c: Slope of first insulating film Reference numeral 18 denotes an alignment film as a first alignment film, 20 denotes a counter substrate as a second substrate, 23 denotes a common electrode as a second electrode, 24 denotes an alignment film as a second alignment film, 30 denotes a thin film transistor as a transistor (TFT), 50: liquid crystal layer, 100: liquid crystal device, 200: liquid crystal device, 1000: liquid crystal projector as projection display device, 1206: cross dichroic prism as light combining means, 1207: projection lens, 1250: first light A liquid crystal light valve as a modulating means, 1260... A liquid crystal light valve as a second light modulating means, and 1270 a liquid crystal light as a third light modulating means. Lube, CNT5 ... contact hole as a contact portion, P ... pixel, P (A) ... first region, P (B) ... second region.

Claims (11)

A first substrate having a reflective first electrode , a first insulating film covering the first electrode, and a first alignment film that is an obliquely deposited film on the first insulating film;
A second substrate having a light-transmitting second electrode and a second alignment film that is an oblique deposition film;
A liquid crystal layer provided between the first substrate and the second substrate;
A plurality of regions having different optical distances D between the first electrode and the center of the first alignment film in the thickness direction are provided in the pixel ,
The liquid crystal device, wherein a difference ΔD between the optical distances D in the plurality of regions satisfies the following equation (1).
0.225λ ≦ ΔD ≦ 0.275λ (1)
(Λ is the wavelength of light incident on the first electrode) The plurality of regions include a first region and a second region where the optical distance D is different,
The liquid crystal device according to claim 1, wherein an area ratio of the first region and an area ratio of the second region to an opening area of the pixel are the same. The difference ΔD between the optical distances D in the plurality of regions satisfies the following equation (2):
The liquid crystal device according to claim 1 .
ΔD = 0.25λ (2) The thickness of the first electrode in a plurality of regions are different, the liquid crystal device according to any one of claims 1 to 3. The thickness of the first insulating film in a plurality of regions are different, the liquid crystal device according to any one of claims 1 to 3. The boundary between the plurality of regions is parallel or perpendicular to the vibration direction of the electric field of the incident light,
The liquid crystal device according to any one of claims 1 to 5. The boundary between the plurality of regions is parallel or perpendicular to the vibration direction of the electric field of the incident light,
The liquid crystal device according to claim 4 , wherein the first electrode has a slope at a boundary between the plurality of regions. The boundary between the plurality of regions is parallel or perpendicular to the vibration direction of the electric field of the incident light,
The liquid crystal device according to claim 5 , wherein the first insulating film has a slope at a boundary between the plurality of regions. The pixel is provided with a transistor as a switching element,
Contact portion for electrically connecting the said transistor first electrode overlaps the boundary portion of the plurality of regions in a plan view, the liquid crystal device according to any one of claims 6-8. Including the liquid crystal device according to any one of claims 1 to 9, the electronic device. A lighting device that can emit three color lights,
First light modulation means for modulating red light among the three color lights;
Second light modulating means for modulating green light among the three color lights;
Third light modulating means for modulating blue light among the three color lights;
Light combining means for combining light modulated by each of the first light modulating means, the second light modulating means, and the third light modulating means into display light;
And a projection lens for projecting the display light,
The liquid crystal device according to any one of claims 1 to 9 , wherein at least the third light modulating means among the first light modulating means, the second light modulating means, and the third light modulating means is used. Is a projection display device.

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