JP2012247663A - Liquid crystal device, projection type display device, and electronic appliance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal device in which deterioration of display quality due to aggregation of ionic impurities in an image display region can be prevented by neutralizing the ionic impurities into non-ionic impurities, and provide a projection type display device and an electronic appliance including the liquid crystal device.SOLUTION: A liquid crystal device 100 includes a first electrode 81 and a second electrode 82 which are in contact with a liquid crystal layer 50 in a peripheral region 10b of an element substrate 10 and a counter substrate 20. Different potentials are applied to the first electrode 81 and the second electrode 82. The first electrode 81 has a structure in which a first charge injection layer 812 is stacked on a first conductive layer 811, and the second electrode 82 has a structure in which a second charge injection layer 822 is stacked on a second conductive layer 821. Thus, ionic impurities exchange charges with the first electrode 81 or the second electrode 82 to become non-ionic impurities.

Description

  The present invention relates to a liquid crystal device in which a liquid crystal layer is held between a pair of substrates, a projection display device using the liquid crystal device as a light valve, and an electronic apparatus.

  In a liquid crystal device, an element substrate provided with an image display region in which a plurality of pixel electrodes are arranged on one surface side and a counter substrate provided with a common electrode to which a common potential is applied are bonded together by a sealing material, A liquid crystal layer is held in a region surrounded by a sealing material between the substrate and the counter substrate. In such a liquid crystal device, when the ionic impurities mixed at the time of liquid crystal injection or the ionic impurities eluted from the sealing material are aggregated in the image display region as the liquid crystal device is driven, the liquid crystal is liquidated in the region where the ionic impurities are aggregated. As a result, it becomes impossible to drive the layers properly, resulting in deterioration of display quality such as image burn-in. Therefore, a technique has been proposed in which an electrode for trapping ionic impurities is provided outside the image display region, and the ionic impurities are attracted and retained on the electrode (see Patent Documents 1 and 2).

  For example, in Patent Document 1, a first electrode for trapping an ionic impurity covered with an alignment film is provided outside an image display region of an element substrate, while being covered with an alignment film outside the image display region of a counter substrate. There has been proposed a technique of providing a second electrode for trapping ionic impurities and electrostatically trapping ionic impurities by a DC voltage applied between the first electrode and the second electrode. In Patent Document 2, a first electrode and a second electrode for ionic impurity trapping covered with an alignment film are provided outside the image display region of the element substrate, and the first electrode and the second electrode are provided between the first electrode and the second electrode. Techniques have been proposed for electrostatically trapping ionic impurities with an applied AC voltage.

FIG. 1 of JP-A-2002-196355 FIG. 3 of Japanese Patent Laid-Open No. 2008-58497

  However, in the configuration in which ionic impurities are electrostatically trapped as in the techniques described in Patent Documents 1 and 2, since the amount of ionic impurities that can be trapped is small, the ionicity that tends to aggregate in the image display region There is a problem that impurities cannot be attracted sufficiently and trapped.

  In view of the above problems, the object of the present invention is to neutralize ionic impurities into nonionic impurities, thereby preventing deterioration in display quality due to aggregation of ionic impurities in the image display region. An object of the present invention is to provide a liquid crystal device that can be used, a projection display device including the liquid crystal device, and an electronic device.

  In order to solve the above problems, a liquid crystal device according to the present invention includes an element substrate in which a pixel electrode and an alignment film are provided in an image display region, and a counter substrate in which a common electrode and an alignment film are provided in the image display region. A sealing material for bonding the element substrate and the counter substrate, a liquid crystal layer held in a region surrounded by the sealing material between the element substrate and the counter substrate, the element substrate and the counter substrate A first electrode provided in a region sandwiched between the image display region of at least one of the substrates and the sealing material; and the image display of at least one of the element substrate and the counter substrate. A second electrode to which a potential different from that of the first electrode is applied, the at least one of the first electrode and the second electrode being provided in a region sandwiched between the region and the sealing material Square of electrodes includes a conductive layer, is laminated on the side of the liquid crystal layer is positioned relative to the conductive layer, and a, a charge injection layer in contact with the liquid crystal layer.

  In the present invention, the first electrode and the second electrode are provided in a region sandwiched between the image display region and the sealing material in the element substrate or the counter substrate, and different potentials are applied to the first electrode and the second electrode. ing. For this reason, ionic impurities in the image display region are attracted to the first electrode and the second electrode. Here, at least one of the first electrode and the second electrode has a structure in which a charge injection layer is laminated on a side where the liquid crystal layer is located with respect to the conductive layer. It is in contact with the liquid crystal layer. Accordingly, the ionic impurities attracted to the first electrode or the second electrode transfer charges to or from the first electrode or the second electrode, and become nonionic impurities outside the image display region. Therefore, unlike the configuration in which the ionic impurities are electrostatically trapped, the ionic impurities discharged outside the image display area can be lost, so that the ionic impurities aggregate in the image display area. High ability to prevent Therefore, according to the present invention, it is difficult for display quality to be deteriorated due to aggregation of ionic impurities.

  In the present invention, the first electrode is provided on one of the element substrate and the counter substrate, and the second electrode is provided on the other substrate of the element substrate and the counter substrate. A configuration can be adopted.

  In the present invention, the first electrode includes a first conductive layer as the conductive layer, and an energy barrier when electrons move from the first conductive layer to the liquid crystal layer side as the charge injection layer. The second electrode includes a second conductive layer as the conductive layer, and the charge injection layer has electrons from the liquid crystal layer side to the second conductive layer. It is possible to employ a configuration including a second charge injection layer that lowers an energy barrier when moving. According to this configuration, both the positive ionic impurities and the negative ionic impurities can be neutralized to nonionic impurities.

  In the present invention, the first charge injection layer is, for example, any one of a hydroxyquinoline-aluminum complex, an azomethine-zinc complex, and a distyrylbiphenyl derivative, and the second charge injection layer is, for example, a phthalocyanine compound. , A triallylamine compound, a perylene compound, and a europium complex.

  In the present invention, a configuration in which a DC voltage having a higher potential on the second electrode side than the first electrode side is applied between the first electrode and the second electrode can be employed.

  In the present invention, a configuration in which an AC voltage is applied between the first electrode and the second electrode may be employed. Even when an AC voltage is applied between the first electrode and the second electrode, the surfaces of the first electrode and the second electrode are in a period in which the first electrode is at a low potential and the second electrode is at a high potential. Thus, the positive ionic impurities and the negative ionic impurities can be neutralized to nonionic impurities.

  In the present invention, since the alignment film is not formed in a region overlapping the charge injection layer on the liquid crystal layer side, the charge injection layer is exposed from the alignment film and is in contact with the liquid crystal layer. The configuration can be adopted.

  In the present invention, in the region overlapping the charge injection layer on the liquid crystal layer side, the alignment film is formed as an inorganic alignment film composed of a plurality of protrusions, so that the charge injection layer is A configuration may be adopted in which the liquid crystal layer is exposed from the alignment film between the portions.

  A liquid crystal device to which the present invention is applied can be used in a projection display device, and the projection display device emits light supplied to the liquid crystal device and light modulated by the liquid crystal device. A projection optical system for projecting.

  The projection display device according to the present invention can be used in various electronic devices other than the projection display device.

1 is a block diagram showing an electrical configuration of a liquid crystal device according to Embodiment 1 of the present invention. It is explanatory drawing of the liquid crystal panel of the liquid crystal device which concerns on Embodiment 1 of this invention. It is explanatory drawing of the electrode etc. which are formed in the element substrate of the liquid crystal device which concerns on Embodiment 1 of this invention. 2 is a plan view of a plurality of adjacent pixels in the element substrate used in the liquid crystal device according to Embodiment 1 of the present invention. FIG. It is explanatory drawing which shows the cross-sectional structure of the liquid crystal device which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows typically the electrode for the ionic impurity trap of the liquid crystal device which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows typically the electrode for the ionic impurity trap of the liquid crystal device which concerns on Embodiment 2 of this invention. It is explanatory drawing which shows typically the electrode for the ionic impurity trap of the liquid crystal device which concerns on Embodiment 3 of this invention. It is explanatory drawing which shows typically the electrode for the ionic impurity trap of the liquid crystal device which concerns on Embodiment 4 of this invention. It is explanatory drawing which shows typically the electrode for the ionic impurity trap of the liquid crystal device which concerns on Embodiment 5 of this invention. It is a schematic block diagram of the projection type display apparatus using the liquid crystal device to which this invention is applied.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings to be referred to in the following description, the scales are different for each layer and each member so that each layer and each member have a size that can be recognized on the drawing. Note that when the direction of the current flowing through the field effect transistor is reversed, the source and the drain are interchanged. However, in the following description, for convenience, the side to which the pixel electrode is connected is used as the drain and the data line is connected. The side will be described as a source. Further, when describing the layers formed on the element substrate, the upper layer side or the surface side means the side opposite to the side where the substrate body of the element substrate is located (the side on which the counter substrate is located), and the lower layer side means It means the side where the substrate body of the element substrate is located (the side opposite to the side where the counter substrate is located).

[Embodiment 1]
(Electrical configuration of image display area, etc.)
FIG. 1 is a block diagram showing an electrical configuration of the liquid crystal device according to Embodiment 1 of the present invention. FIG. 1 is a block diagram showing the electrical configuration to the last, and does not show the shape or extending direction of the wiring or electrode, the layout, or the like. In this embodiment, the “first substrate” in the present invention corresponds to the element substrate 10, and the “second substrate” corresponds to the counter substrate 20.

  In FIG. 1, a liquid crystal device 100 has a liquid crystal panel 100p in a TN (Twisted Nematic) mode or a VA (Vertical Alignment) mode, and the liquid crystal panel 100p has a plurality of pixels 100a arranged in a matrix in the central region. The image display area 10a (pixel array area / effective pixel area) is provided. In the liquid crystal panel 100p, in an element substrate 10 (see FIG. 2 and the like) described later, a plurality of data lines 6a (image signal lines) and a plurality of scanning lines 3a extend vertically and horizontally inside the image display region 10a. A pixel 100a is formed at a position corresponding to the intersection. In each of the plurality of pixels 100a, a pixel transistor 30 made of a field effect transistor and a pixel electrode 9a described later are formed. The data line 6 a is electrically connected to the source of the pixel transistor 30, the scanning line 3 a is electrically connected to the gate of the pixel transistor 30, and the pixel electrode 9 a is electrically connected to the drain of the pixel transistor 30. Has been.

  In the element substrate 10, a scanning line driving circuit 104 and a data line driving circuit 101 are provided on the outer peripheral side of the image display region 10 a. The data line driving circuit 101 is electrically connected to each data line 6a, and sequentially supplies the image signal supplied from the image processing circuit to each data line 6a. The scanning line driving circuit 104 is electrically connected to each scanning line 3a, and sequentially supplies a scanning signal to each scanning line 3a.

  In each pixel 100a, the pixel electrode 9a is opposed to a common electrode formed on a counter substrate 20 (see FIG. 2 and the like), which will be described later, via a liquid crystal layer, and constitutes a liquid crystal capacitor 50a. Further, a storage capacitor 55 is added to each pixel 100a in parallel with the liquid crystal capacitor 50a in order to prevent fluctuation of the image signal held in the liquid crystal capacitor 50a. In this embodiment, in order to configure the storage capacitor 55, the element substrate 10 is provided with a capacitor line 5b extending across the plurality of pixels 100a. In this embodiment, the capacitor line 5b is electrically connected to the constant potential wiring 6s to which the common potential Vcom is applied.

  In this embodiment, as will be described in detail later, the element substrate 10 is supplied with a first electrode 81 for trapping ionic impurities and a predetermined potential supplied to the first electrode 81 on the outer peripheral side of the image display region 10a. An electric wire 87 is formed. In this embodiment, the power supply line 87 extends from the data line driving circuit 101.

(Configuration of liquid crystal panel 100p and element substrate 10)
FIG. 2 is an explanatory diagram of the liquid crystal panel 100p of the liquid crystal device 100 according to Embodiment 1 of the present invention. FIGS. 2A and 2B each show the liquid crystal panel 100p together with each component on the side of the counter substrate. It is the top view seen from and HH 'sectional drawing. FIG. 3 is an explanatory diagram of electrodes and the like formed on the element substrate 10 of the liquid crystal device 100 according to Embodiment 1 of the present invention. FIGS. 3 (a) and 3 (b) are formed on the entire element substrate 10. It is explanatory drawing of the electrode etc. which are used, and explanatory drawing of a dummy pixel electrode. Note that in FIG. 3 and the like, the number of pixel electrodes 9a is small.

  As shown in FIG. 2, in the liquid crystal panel 100 p, the element substrate 10 and the counter substrate 20 are bonded to each other with a seal material 107 through a predetermined gap, and the seal material 107 is framed along the outer edge of the counter substrate 20. It is provided in the shape. The sealing material 107 is an adhesive made of a photo-curing resin, a thermosetting resin, or the like, and is mixed with a gap material 107a such as glass fiber or glass beads for setting the distance between both substrates to a predetermined value. In the liquid crystal panel 100p, the liquid crystal layer 50 is held in a region surrounded by the sealant 107 between the element substrate 10 and the counter substrate 20. In this embodiment, the sealing material 107 is formed with a discontinuous portion 107c used as a liquid crystal injection port, and the discontinuous portion 107c is closed by the sealing material 108 after the liquid crystal material is injected.

  As shown in FIGS. 2 and 3A, in the liquid crystal panel 100p, the element substrate 10 and the counter substrate 20 are both square, and the image described with reference to FIG. The display area 10a is provided as a rectangular area. Corresponding to this shape, the sealing material 107 is also provided in a substantially square shape, and the outer side of the image display area 10a is a rectangular frame-shaped outer peripheral area 10c.

  In the element substrate 10, the data line driving circuit 101 and a plurality of terminals 102 are formed along one side of the element substrate 10 in the outer peripheral region 10 c, and the scanning line driving circuit 104 is formed along another side adjacent to the one side. Is formed. Note that a flexible wiring board (not shown) is connected to the terminal 102, and various potentials and various signals are input to the element substrate 10 through the flexible wiring board.

  As will be described in detail later, the pixel transistor described with reference to FIG. 1 is provided in the image display region 10a on the one surface 10s side of the element substrate 10 facing the counter substrate 20 out of the one surface 10s and the other surface 10t. 30 and pixel electrodes 9a electrically connected to the pixel transistors 30 are formed in a matrix, and an alignment film 16 is formed on the upper layer side of the pixel electrodes 9a.

  Further, on the one surface 10 s side of the element substrate 10, in the outer peripheral region 10 c outside the image display region 10 a, the rectangular frame-shaped peripheral region 10 b sandwiched between the image display region 10 a and the sealing material 107 includes pixels. A dummy pixel electrode 9b formed simultaneously with the electrode 9a is formed.

  As shown in FIG. 3B, in the dummy pixel electrode 9b, adjacent dummy pixel electrodes 9b are connected to each other by a narrow connecting portion 9u. The dummy pixel electrode 9b compresses the difference in height between the image display region 10a and the peripheral region 10b when the surface on which the alignment film 16 is formed on the element substrate 10 is flattened by polishing. This contributes to flattening the surface to be formed. In the present embodiment, a first electrode 81 for trapping ionic impurities, which will be described later, is configured using the dummy pixel electrode 9b.

  In FIG. 2 again, the common electrode 21 is formed on the one surface 20 s facing the element substrate 10 out of the one surface 20 s and the other surface 20 t of the counter substrate 20. The common electrode 21 is formed across the plurality of pixels 100a as substantially the entire surface of the counter substrate 20 or a plurality of strip electrodes. In this embodiment, the common electrode 21 is formed on substantially the entire surface of the counter substrate 20.

  A light shielding layer 29 is formed on the lower side of the common electrode 21 on the one surface 20 s side of the counter substrate 20, and an alignment film 26 is laminated on the surface of the common electrode 21. In this embodiment, the light shielding layer 29 is formed as a frame portion 29a extending along the outer periphery of the image display region 10a, and the image display region 10a is defined by the inner periphery of the frame portion 29a. In this embodiment, the light shielding layer 29 is also formed as a black matrix portion 29b that overlaps the inter-pixel region 10f sandwiched between the adjacent pixel electrodes 9a. Here, the frame portion 29 a is formed at a position overlapping the dummy pixel electrode 9 b, and the outer peripheral edge of the frame portion 29 a is at a position with a gap between it and the inner peripheral edge of the sealing material 107. Therefore, the frame portion 29a and the sealing material 107 do not overlap.

  In the liquid crystal panel 100p, the inter-substrate conduction electrode portions 25t are formed on the four corners on the one surface 20s side of the counter substrate 20 outside the sealing material 107, and the element substrate 10 side on the one surface 10s side. The inter-substrate conduction electrode portion 6t is formed at a position facing the four corners of the counter substrate 20 (inter-substrate conduction electrode portion 25t). In this embodiment, the inter-substrate conduction electrode portion 25 t is formed of a part of the common electrode 21. The inter-substrate conduction electrode portion 6t is electrically connected to the constant potential wiring 6s to which the common potential Vcom is applied, and the constant potential wiring 6s is electrically connected to the common potential application terminal 102a among the terminals 102. An inter-substrate conducting material 109 containing conductive particles is disposed between the inter-substrate conducting electrode portion 6t and the inter-substrate conducting electrode portion 25t, and the common electrode 21 of the counter substrate 20 serves as an inter-substrate conducting electrode. It is electrically connected to the element substrate 10 side through the electrode portion 6t, the inter-substrate conducting material 109, and the inter-substrate conducting electrode portion 25t. Therefore, the common potential Vcom is applied to the common electrode 21 from the element substrate 10 side. The sealing material 107 is provided along the outer peripheral edge of the counter substrate 20 with substantially the same width dimension. For this reason, the sealing material 107 is substantially rectangular. However, the sealing material 107 is provided so as to pass through the inside avoiding the inter-substrate conduction electrode portions 6t and 25t in the region overlapping the corner portion of the counter substrate 20, and the corner portion of the sealing material 107 is substantially arc-shaped. is there.

  In the liquid crystal device 100 having such a configuration, in this embodiment, the pixel electrode 9a and the common electrode 21 are formed of a light-transmitting conductive film such as an ITO (Indium Tin Oxide) film or an IZO (Indium Zinc Oxide) film. Reference numeral 100 denotes a transmissive liquid crystal device. In the transmissive liquid crystal device 100, light incident from the counter substrate 20 side is modulated while being transmitted through the element substrate 10 and emitted to display an image. Of the pixel electrode 9a and the common electrode 21, for example, the common electrode 21 may be formed of a light-transmitting conductive film, and the pixel electrode 9a may be formed of a reflective conductive film such as an aluminum film. In this case, the reflective liquid crystal device 100 can be configured. In the reflective liquid crystal device 100, light incident from the counter substrate 20 side of the element substrate 10 and the counter substrate 20 is modulated while being reflected by the element substrate 10 and emitted to display an image.

  The liquid crystal device 100 can be used as a color display device of an electronic device such as a mobile computer or a mobile phone. In this case, a color filter (not shown) is formed on the counter substrate 20 or the element substrate 10. Further, in the liquid crystal device 100, the polarizing film, the retardation film, the polarizing plate, etc. have a predetermined orientation with respect to the liquid crystal panel 100p according to the type of the liquid crystal layer 50 to be used and the normally white mode / normally black mode. Placed in. Furthermore, the liquid crystal device 100 can be used as a light valve for RGB in a projection display device (liquid crystal projector) described later. In this case, each color liquid crystal device 100 for RGB receives light of each color separated through RGB color separation dichroic mirrors as projection light, so that no color filter is formed.

  In this embodiment, the liquid crystal device 100 is a transmissive liquid crystal device used as a RGB light valve in a projection display device described later, and light incident from the counter substrate 20 is transmitted through the element substrate 10 and emitted. The case will be mainly described. Further, in the present embodiment, the liquid crystal device 100 will be described focusing on a case where the liquid crystal device 100 includes a VA mode liquid crystal panel 100p using a nematic liquid crystal compound having a negative dielectric anisotropy as the liquid crystal molecules of the liquid crystal layer 50.

(Specific configuration of pixels, etc.)
FIG. 4 is a plan view of a plurality of adjacent pixels in the element substrate 10 used in the liquid crystal device 100 according to Embodiment 1 of the present invention. 5 is an explanatory diagram showing a cross-sectional configuration of the liquid crystal device 100 according to Embodiment 1 of the present invention, and FIGS. 5A and 5B are cross-sectional views of the pixel shown in FIG. It is sectional drawing of the outer periphery area | region 10c. In FIG. 4, the light shielding layer 8a on the lower layer side = thin and long broken line Semiconductor layer 1a = thin and short dotted line Scan line 3a = thick solid line Drain electrode 4a = thin solid line Data line 6a and relay electrode 6b = Thin alternate long and short dashed lines Capacitance line 5b = thick alternate long and short dashed line Light-shielding layer 7a on the upper layer side and relay electrode 7b = thin alternate long and two short dashed line Pixel electrode 9a = shown by a thick broken line. In FIG. 4, the positions of the end portions of the layers overlapping with each other are shifted so that the shape of the layer can be easily understood.

  As shown in FIG. 4, on one surface 10 s of the element substrate 10 facing the counter substrate 20, pixel electrodes 9 a are formed on each of the plurality of pixels 100 a, and between the pixels sandwiched between adjacent pixel electrodes 9 a. A data line 6a and a scanning line 3a are formed along the region 10f. In this embodiment, the inter-pixel region 10f extends vertically and horizontally, and the scanning line 3a is linear along the first inter-pixel region 10g extending in the X direction (first direction) in the inter-pixel region 10f. The data line 6a extends linearly along the second inter-pixel region 10h extending in the Y direction (second direction). Further, a pixel transistor 30 is formed corresponding to the intersection of the data line 6a and the scanning line 3a. In this embodiment, the pixel transistor 30 uses the intersection region of the data line 6a and the scanning line 3a and its vicinity. Is formed. A capacitance line 5b is formed on the element substrate 10, and a common potential Vcom is applied to the capacitance line 5b. In this embodiment, the capacitor line 5b is formed in a lattice shape extending so as to overlap the scanning line 3a and the data line 6a. A light shielding layer 7a is formed on the upper layer side of the pixel transistor 30, and the light shielding layer 7a extends so as to overlap the data line 6a. A light shielding layer 8a is formed on the lower layer side of the pixel transistor 30, and the light shielding layer 8a is an intersection between the main line portion linearly extending so as to overlap the scanning line 3a and the data line 6a and the scanning line 3a. And a sub-line portion extending so as to overlap the data line 6a.

  As shown in FIG. 5A, the element substrate 10 is disposed on the substrate surface (on the one surface 10s facing the counter substrate 20) on the liquid crystal layer 50 side of the translucent substrate body 10w such as a quartz substrate or a glass substrate. The pixel electrode 9a, the pixel transistor 30 for pixel switching, and the alignment film 16 are mainly formed. The counter substrate 20 includes a translucent substrate body 20w such as a quartz substrate or a glass substrate, a light shielding layer 29 formed on a surface of the liquid crystal layer 50 side (one surface 20s facing the element substrate 10), a common electrode 21, And the alignment film 26 as a main component.

  In the element substrate 10, a lower light shielding layer 8 a made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal compound film is formed on the one surface 10 s side of the substrate body 10 w. . In this embodiment, the light shielding layer 8a is made of a light shielding film such as tungsten silicide (WSi), and when the light after passing through the liquid crystal device 100 is reflected by another member, the reflected light is incident on the semiconductor layer 1a. The pixel transistor 30 is prevented from malfunctioning due to photocurrent. The light shielding layer 8a may be configured as a scanning line. In this case, the gate electrode 3c described later and the light shielding layer 8a are electrically connected.

A translucent insulating film 12 is formed on the upper surface side of the light shielding layer 8a on the one surface 10s side of the substrate body 10w, and the pixel transistor 30 including the semiconductor layer 1a on the surface side of the insulating film 12 is provided. Is formed. In this embodiment, the insulating film 12 is a silicon oxide film (including silicate glass) such as NSG (non-silicate glass), PSG (phosphorus silicate glass), BSG (boron silicate glass), or BPSG (boron phosphorus silicate glass). And made of a silicon nitride film. The insulating film 12 is formed of silane gas (SiH ₄ ), silane dichloride (SiCl ₂ H ₂ ), TEOS (tetraethoxysilane / tetraethylorthosilicate / Si (OC ₂ H ₅ ) ₄ ), TEB (tetra · It is formed by an atmospheric pressure CVD method, a low pressure CVD method, a plasma CVD method, or the like using ethyl boatrate), TMOP (tetramethyloxyphosphate), or the like.

  The pixel transistor 30 includes a semiconductor layer 1a having a long side direction in the extending direction of the data line 6a, and a central portion in the length direction of the semiconductor layer 1a extending in a direction orthogonal to the length direction of the semiconductor layer 1a. In this embodiment, the gate electrode 3c is formed of a part of the scanning line 3a. The pixel transistor 30 has a translucent gate insulating layer 2 between the semiconductor layer 1a and the gate electrode 3c. The semiconductor layer 1a includes a channel region 1g opposed to the gate electrode 3c via the gate insulating layer 2, and includes a source region 1b and a drain region 1c on both sides of the channel region 1g. In this embodiment, the pixel transistor 30 has an LDD structure. Therefore, each of the source region 1b and the drain region 1c includes a low concentration region on both sides of the channel region 1g, and includes a high concentration region in a region adjacent to the low concentration region on the opposite side to the channel region 1g.

  The semiconductor layer 1a is composed of a polysilicon film (polycrystalline silicon film) or the like. The gate insulating layer 2 includes a first gate insulating layer 2a made of a silicon oxide film obtained by thermally oxidizing the semiconductor layer 1a and a silicon oxide film made of a low pressure CVD method under a high temperature condition of 700 to 900 ° C. It has a two-layer structure with a two-gate insulating layer 2b. The gate electrode 3c and the scanning line 3a are made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal compound film. In this embodiment, the gate electrode 3c has a two-layer structure of a conductive polysilicon film and a tungsten silicide film.

  A translucent interlayer insulating film 41 made of a silicon oxide film such as NSG, PSG, BSG, or BPSG is formed on the upper layer side of the gate electrode 3c, and a drain electrode 4a is formed on the upper layer of the interlayer insulating film 41. Has been. In this embodiment, the interlayer insulating film 41 is made of a silicon oxide film. The drain electrode 4a is made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal compound film. In this embodiment, the drain electrode 4a is made of a titanium nitride film. The drain electrode 4 a is formed so as to partially overlap the drain region 1 c (pixel electrode side source / drain region) of the semiconductor layer 1 a, and through a contact hole 41 a penetrating the interlayer insulating film 41 and the gate insulating layer 2. It is electrically connected to the drain region 1c.

  A translucent etching stopper layer 49 made of a silicon oxide film or the like and a translucent dielectric layer 40 are formed on the upper layer side of the drain electrode 4a, and a capacitance is formed on the upper layer side of the dielectric layer 40. A line 5b is formed. As the dielectric layer 40, a silicon compound such as a silicon oxide film or a silicon nitride film can be used, and an aluminum oxide film, a titanium oxide film, a tantalum oxide film, a niobium oxide film, a hafnium oxide film, a lanthanum oxide film, zirconium A dielectric layer having a high dielectric constant such as an oxide film can be used. The capacitor line 5b is made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal compound film. In this embodiment, the capacitor line 5b has a three-layer structure of a titanium nitride film, an aluminum film, and a titanium nitride film. Here, the capacitor line 5 b overlaps with the drain electrode 4 a through the dielectric layer 40, and constitutes a storage capacitor 55.

  An interlayer insulating film 42 is formed on the upper layer side of the capacitor line 5b. On the upper layer side of the interlayer insulating film 42, the data line 6a and the relay electrode 6b are formed of the same conductive film. The interlayer insulating film 42 is made of a silicon oxide film. The data line 6a and the relay electrode 6b are made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal compound film. In this embodiment, the data line 6a and the relay electrode 6b are made of an aluminum alloy film or a laminated film of two to four layers of a titanium nitride film and an aluminum film. The data line 6a is electrically connected to the source region 1b (data line side source / drain region) through a contact hole 42a penetrating the interlayer insulating film 42, the etching stopper layer 49, the interlayer insulating film 41 and the gate insulating layer 2. The relay electrode 6 b is electrically connected to the drain electrode 4 a through a contact hole 42 b that penetrates the interlayer insulating film 42 and the etching stopper layer 49.

  A light-transmitting interlayer insulating film 44 made of a silicon oxide film or the like is formed on the upper side of the data line 6a and the relay electrode 6b. On the upper layer side of the interlayer insulating film 44, the light shielding layer 7a and the relay electrode 7b are formed. Are formed of the same conductive film. The interlayer insulating film 44 is made of, for example, a silicon oxide film formed by a plasma CVD method using tetraethoxysilane and oxygen gas or a plasma CVD method using silane gas and nitrous oxide gas, and the surface thereof is flat. It has become. The light shielding layer 7a and the relay electrode 7b are made of a conductive film such as a conductive polysilicon film, a metal silicide film, a metal film, or a metal compound film. In this embodiment, the light shielding layer 7a and the relay electrode 7b are made of an aluminum alloy film or a laminated film of two to four layers of a titanium nitride film and an aluminum film. The relay electrode 7 b is electrically connected to the relay electrode 6 b through a contact hole 44 a that penetrates the interlayer insulating film 44. The light shielding layer 7a extends so as to overlap the data line 6a, and functions as a light shielding layer. The light shielding layer 7a may be electrically connected to the capacitor line 5b and used as a shield layer.

  A light-transmitting interlayer insulating film 45 made of a silicon oxide film or the like is formed on the upper side of the light shielding layer 7a and the relay electrode 7b, and a light-transmitting layer such as an ITO film is formed on the upper layer side of the interlayer insulating film 45. A pixel electrode 9a made of a conductive film is formed. In this embodiment, the pixel electrode 9a is made of an ITO film. The interlayer insulating film 45 is made of, for example, a silicon oxide film formed by a plasma CVD method using tetraethoxysilane and oxygen gas or a plasma CVD method using silane gas and nitrous oxide gas, and the surface is flattened. Has been.

  The pixel electrode 9 a partially overlaps the relay electrode 7 b and is electrically connected to the relay electrode 7 b through a contact hole 45 a that penetrates the interlayer insulating film 45. As a result, the pixel electrode 9a is electrically connected to the drain region 1c through the relay electrode 7b, the relay electrode 6b, and the drain electrode 4a.

An alignment film 16 is formed on the surface of the pixel electrode 9a. In this embodiment, the alignment film 16 is an obliquely deposited film of SiO _x (x <2), SiO ₂ , TiO ₂ , MgO, Al ₂ O ₃ , In ₂ O ₃ , Sb ₂ O ₃ , Ta ₂ O ₅ or the like. (Inclined vertical alignment film / inorganic alignment film).

(Configuration of counter substrate 20)
In the counter substrate 20, a light shielding layer 29, a transparent substrate body 20 w (translucent substrate) such as a quartz substrate or a glass substrate, on the liquid crystal layer 50 side surface (one surface 20 s facing the element substrate 10), An insulating film 28 made of a silicon oxide film or the like and a common electrode 21 made of a light-transmitting conductive film such as an ITO film are formed. An alignment film 26 is formed so as to cover the common electrode 21. In this embodiment, the common electrode 21 is made of an ITO film. Similar to the alignment film 16, the alignment film 26 is oblique such as SiO _x (x <2), SiO ₂ , TiO ₂ , MgO, Al ₂ O ₃ , In ₂ O ₃ , Sb ₂ O ₃ , and Ta ₂ O _5. It is a deposited film (tilted vertical alignment film / inorganic alignment film). Such alignment films 16 and 26 schematically show a nematic liquid crystal compound having an alignment regulation force antiparallel and a negative dielectric anisotropy used for the liquid crystal layer 50, and a liquid crystal molecule 50b shown by a solid line L1 in FIG. And tilted vertically. In this way, the liquid crystal panel 100p is configured as a normally black VA mode liquid crystal panel. In the present embodiment, the pretilt direction of the liquid crystal molecules 50b is set such that two corners 10a ₁ , 10a located diagonally out of the _four corners 10a _{1 to} 10a 4 of the image display region 10a as indicated by an arrow P in FIG. It is set in the direction of the diagonal line connecting _three .

(Configuration of the peripheral region 10b)
In FIG. 3 and FIG. 5B, the dummy pixel electrode 9b is used in the peripheral region 10b sandwiched between the image display region 10a and the sealing material 107 on the one surface 10s side of the element substrate 10 to display an image. A first electrode 81 for trapping ionic impurities is formed around the display region 10 a, and a potential Vip for trapping ionic impurities is applied to the first electrode 81.

  As shown in FIG. 5B, the second electrode 82 for trapping ionic impurities is provided in the peripheral region 10b sandwiched between the image display region 10a and the sealing material 107 on the one surface 20s side of the counter substrate 20. The second electrode 82 is formed so as to face the first electrode 81. In this embodiment, the second electrode 82 is configured by using a part of the common electrode 21 and is applied with the common potential Vcom.

Here, different potentials are applied to the first electrode 81 and the second electrode 82. In this embodiment, the common potential Vcom is 0V, and the potential Vip is a negative potential such as −5V. Therefore, the common potential Vcom and the potential Vip are expressed by the following relational potential Vip <common potential Vcom.
It is in.

  In the liquid crystal device 100 configured as described above, in the element substrate 10, the alignment film 16 is not formed on the surface of the first electrode 81. That is, the first electrode 81 is formed in the non-formation region of the alignment film 16 and is in direct contact with the liquid crystal layer 50. The first electrode 81 includes a first conductive layer 811 made of an ITO film (dummy pixel electrode 9b) formed simultaneously with the pixel electrode 9a, and a first charge injection layer stacked on the upper layer side of the first conductive layer 811. 812, and the first charge injection layer 812 is in contact with the liquid crystal layer 50. The first charge injection layer 812 is made of a hydroxyquinoline-aluminum complex, an azomethine-zinc complex, or a distyrylbiphenyl derivative. Such a material is a material used as an electron injection layer in the organic electroluminescence element, and has a function of lowering an energy barrier when electrons move from the first conductive layer 811 to the liquid crystal layer 50 side. In this embodiment, a hydroxyquinoline-aluminum complex layer is formed as the first charge injection layer 812.

  On the other hand, in the counter substrate 20, the alignment film 26 is not formed on the surface of the second electrode 82. That is, the second electrode 82 is formed in a region where the alignment film 26 is not formed, and is in direct contact with the liquid crystal layer 50. The second electrode 82 includes a second conductive layer 821 made of a part of the ITO film constituting the common electrode 21, and a second charge injection layer 822 stacked on the upper side of the second conductive layer 821. The second charge injection layer 822 is in contact with the liquid crystal layer 50. The second charge injection layer 822 is made of a phthalocyanine compound, a triallylamine compound, a perylene compound, or a europium complex. Such a material is a material used as a hole injection layer in the organic electroluminescence element, and has a function of lowering an energy barrier when electrons move from the liquid crystal layer side to the second conductive layer 821. In this embodiment, a copper phthalocyanine compound layer is formed as the second charge injection layer 822.

  Although not illustrated, the data line driver circuit 101 and the scan line driver circuit 104 described with reference to FIGS. 1 and 2 include an n-channel driving transistor and a p-channel driving transistor. Complementary transistor circuits and the like are provided. Here, the driving transistor is formed by utilizing a part of the manufacturing process of the pixel transistor 30. Therefore, the region where the data line driving circuit 101 and the scanning line driving circuit 104 are formed in the element substrate 10 also has a cross-sectional configuration substantially similar to the cross-sectional configuration shown in FIG.

(Ionic impurity trapping and non-ionization)
FIG. 6 is an explanatory view schematically showing electrodes for trapping ionic impurities of the liquid crystal device 100 according to Embodiment 1 of the present invention.

In FIG. 5, when the voltage applied between the pixel electrode 9a and the common electrode 21 exceeds the threshold voltage, the liquid crystal molecules 50b used in the liquid crystal layer 50 are changed to a posture indicated by a solid line L1 and a posture indicated by a dotted line L2. As a result, weak flow indicated by arrows F1 and F2 is generated in the liquid crystal layer 50. For this reason, the ionic impurities eluted into the liquid crystal layer 50 from the sealing material 107 or the like tend to aggregate at the corners 10a ₁ and 10a ₃ of the image display region 10a. Therefore, in the liquid crystal device 100 of the present embodiment, the liquid crystal device 100 is operated at the stage of displaying an image or before the liquid crystal device 100 is shipped, and the first electrode 81 and the second electrode as described below. The ionic impurities present inside the image display region 10a in the liquid crystal layer 50 are attracted to the outside of the image display region 10a by the potential applied between the electrode 82 and the ionic impurities attracted to the nonionic impurities. To become sexual.

More specifically, as shown in FIG. 6, when the liquid crystal device 100 is operated, the potential Vip for trapping ionic impurities is applied to the first electrode 81 on the element substrate 10 side, while the counter substrate 20. The common potential Vcom is applied to the second electrode 82, and the common potential Vcom and the potential Vip have the following relational potential Vip <common potential Vcom.
It is in. Accordingly, among the ionic impurities in the image display region 10 a, the positive ionic impurity ions M ⁺ are attracted to the first electrode 81, while the negative ionic impurity ions X ⁻ are attracted to the second electrode 82. Gravitate. Here, in the first electrode 81, since the first charge injection layer 812 is formed on the upper side of the first conductive layer 811 made of an ITO film, the positive ionic impurity attracted to the first electrode 81 is formed. The ion M ⁺ is represented by the following formula: M ⁺ + e ⁻ = M
As shown, the electron e ⁻ is received from the first electrode 81 and becomes the nonionic impurity M. In addition, since the second charge injection layer 822 is formed on the second electrode 82 on the upper side of the second conductive layer 821 made of an ITO film, negative ionic impurity ions attracted to the second electrode 82 are formed. X ⁻ represents the following formula: X ⁻ = X + e ⁻
As shown, the electron e ⁻ is transferred to the second electrode 82 and becomes a nonionic impurity X.

As described above, the ionic impurities M ⁺ and X ^{− that} are to be aggregated at the end of the image display region 10 a are attracted to the outside of the image display region 10 a and are neutralized by the nonionic impurities M and X. .

(Main effects of this form)
As described above, in the liquid crystal device 100 of the present embodiment, the first electrode 81 in contact with the liquid crystal layer 50 is disposed in the peripheral region 10b sandwiched between the image display region 10a and the sealing material 107 in the element substrate 10 and the counter substrate 20. And a second electrode 82, and different potentials are applied to the first electrode 81 and the second electrode 82. For this reason, the ionic impurities in the image display region 10 a are attracted to the first electrode 81 and the second electrode 82. Here, the first electrode 81 has a structure in which the first charge injection layer 812 is laminated on the side where the liquid crystal layer 50 is located with respect to the first conductive layer 811, and the second electrode 82 has the second conductive layer. The second charge injection layer 822 is stacked on the side where the liquid crystal layer 50 is located with respect to the layer 821. Accordingly, the ionic impurities attracted to the first electrode 81 or the second electrode 82 exchange charges with the first electrode 81 or the second electrode 82, and nonionic impurities are generated outside the image display region 10a. It becomes. Therefore, unlike the configuration in which the ionic impurities are electrostatically trapped, the ionic impurities discharged to the outside of the image display region 10a can be eliminated, and the ionic impurities are aggregated in the image display region 10a. High ability to prevent Therefore, according to this embodiment, it is difficult for display quality to be deteriorated due to aggregation of ionic impurities.

Therefore, an acceleration test in which light irradiation (3 W / cm ² ) is performed with a metal halide lamp at a temperature of 80 ° C. is performed on the liquid crystal device 100 of this embodiment, and display unevenness is recognized in the peripheral portion of the image display region 10a. As a result, it took a very long time of 2500 hours for display unevenness to be recognized in the periphery of the image display area 10a. On the other hand, when a similar acceleration test was performed on Reference Example 1 in which no potential was applied to the first electrode 81 and the second electrode 82, display unevenness was recognized in the peripheral portion of the image display region 10a in 300 hours. It was. A similar acceleration test was performed on Reference Example 2 in which a DC voltage of +5 v was applied to the first electrode 81 and the second electrode 82 without providing the first charge injection layer 812 and the second charge injection layer 822. Display unevenness was recognized in the periphery of the image display area 10a over time. As described above, according to the present embodiment, it was confirmed that display quality deterioration due to aggregation of ionic impurities hardly occurs.

[Embodiment 2]
FIG. 7 is an explanatory view schematically showing electrodes for trapping ionic impurities of the liquid crystal device 100 according to Embodiment 2 of the present invention. In this embodiment, the “first substrate” in the present invention corresponds to the counter substrate 20, and the “second substrate” corresponds to the element substrate 10. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 7, in the liquid crystal device 100 of the present embodiment, the first electrode 81 is formed on the counter substrate 20 using a part of the ITO film constituting the common electrode 21, contrary to the first embodiment. The second electrode 82 is formed on the element substrate 10 using the dummy pixel electrode 9b. In the liquid crystal device 100 configured as described above, different potentials are applied to the first electrode 81 and the second electrode 82. In this embodiment, the common potential Vcom applied to the first electrode 81 is 0V, and the potential Vip applied to the second electrode 82 is a positive potential such as + 5V. Therefore, the common potential Vcom and the potential Vip are expressed by the following relational potential Vip> common potential Vcom
It is in.

  Here, in the counter substrate 20, the alignment film 26 is not formed on the surface of the first electrode 81, and the first electrode 81 is in direct contact with the liquid crystal layer 50. The first electrode 81 includes a first conductive layer 811 made of an ITO film simultaneously formed with the common electrode 21 and a first charge injection layer 812 stacked on the upper layer side of the first conductive layer 811. The first charge injection layer 812 is in contact with the liquid crystal layer 50. The first charge injection layer 812 is made of a hydroxyquinoline-aluminum complex, an azomethine-zinc complex, or a distyrylbiphenyl derivative. In the element substrate 10, the alignment film 16 is not formed on the surface of the second electrode 82, and the second electrode 82 is in direct contact with the liquid crystal layer 50. The second electrode 82 includes a second conductive layer 821 made of an ITO film constituting the dummy pixel electrode 9b, and a second charge injection layer 822 stacked on the upper side of the second conductive layer 821. The second charge injection layer 822 is in contact with the liquid crystal layer 50. The second charge injection layer 822 is made of a phthalocyanine compound, a triallylamine compound, a perylene compound, or a europium complex.

When the liquid crystal device 100 configured as described above is operated, the potential Vip for trapping ionic impurities is applied to the second electrode 82 on the element substrate 10 side, while the first electrode 81 of the counter substrate 20 is commonly used. The potential Vcom is applied, and the common potential Vcom and the potential Vip have the following relationship: common potential Vcom <potential Vip
It is in. Therefore, of the ionic impurities in the image display region 10a, M ⁺ is a positive ionic impurity ions are attracted to the first electrode 81, electrons e from the first electrode 81 ^- the receiving result, the non-ionic impurities M It becomes. Further, the negative ionic impurity ions X ⁻ are attracted to the second electrode 82, and the electrons e ⁻ are transferred to the second electrode 82, resulting in the nonionic impurities X. Therefore, the liquid crystal device 100 of the present embodiment also has the same effect as that of the first embodiment.

[Embodiment 3]
FIG. 8 is an explanatory view schematically showing an ionic impurity trapping electrode of the liquid crystal device 100 according to Embodiment 3 of the present invention. FIGS. 8A and 8B show the first electrode 81 as shown in FIG. It is explanatory drawing of the period when it is a high potential, and explanatory drawing of the period when the 1st electrode 81 is a low potential. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  8A and 8B, in the liquid crystal device 100 of the present embodiment as well, the first electrode 81 is formed on the element substrate 10 and the second electrode 82 is formed on the counter substrate 20 as in the first embodiment. Has been. The first electrode 81 includes a first conductive layer 811 made of an ITO film, and a first charge injection layer 812 made of a hydroxyquinoline-aluminum complex, an azomethine-zinc complex, or a distyrylbiphenyl derivative. The one charge injection layer 812 is in contact with the liquid crystal layer 50. The second electrode 82 includes a second conductive layer 821 made of an ITO film, and a second charge injection layer 822 made of a phthalocyanine compound, a triallylamine compound, a perylene compound, or a europium complex. 822 is in contact with the liquid crystal layer 50.

  When the liquid crystal device 100 configured as described above is operated, a common potential Vcom having a constant potential (0 V) is applied to the second electrode 82 of the counter substrate 20, while the first electrode 81 on the element substrate 10 side is applied to the first electrode 81. AC potential Vip such as ± 5V is applied.

Therefore, as shown in FIG. 8A, during the period of the potential Vip> the common potential Vcom, the positive ionic impurity ions M ⁺ are attracted to the second electrode 82, and the negative ionic impurity ions X ⁻ Is attracted to the first electrode 81.

On the other hand, as shown in FIG. 8B, in the period of potential Vip <common potential Vcom, positive ionic impurity ions M ⁺ are attracted to the first electrode 81 and electrons are transmitted from the first electrode 81. As a result of receiving e ⁻ , it becomes a nonionic impurity M. Further, the negative ionic impurity ions X ⁻ are attracted to the second electrode 82, and the electrons e ⁻ are transferred to the second electrode 82, resulting in the nonionic impurities X. Therefore, the liquid crystal device 100 of the present embodiment also has the same effect as that of the first embodiment.

[Embodiment 4]
FIG. 9 is an explanatory diagram schematically showing electrodes for trapping ionic impurities of the liquid crystal device 100 according to Embodiment 4 of the present invention. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  In the above-described embodiment, the first electrode 81 and the second electrode 82 are in contact with the liquid crystal layer 50 by not providing the alignment films 16 and 26 in the region where the first electrode 81 and the second electrode 82 are formed. did. On the other hand, in the present embodiment, as shown in FIG. 9, a plurality of layers extending obliquely are formed by forming an inorganic alignment film such as a silicon oxide film in the image display region 10a and the peripheral region 10b by oblique deposition. An alignment film 16 having a column structure provided with convex portions 16a is formed. According to the alignment film 16 having such a configuration, the first charge injection layer 812 is exposed from the alignment film 16 at the interval 16b between the convex portions 16a and is in contact with the liquid crystal layer 50. Also, if the alignment film 26 has the same configuration as the alignment film 16, the second charge injection layer 822 is exposed from the alignment film 26 between the convex portions 26 a and is in contact with the liquid crystal layer 50.

[Embodiment 5]
FIG. 10 is an explanatory view schematically showing electrodes for trapping ionic impurities of the liquid crystal device 100 according to Embodiment 5 of the present invention. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  In the above embodiment, one of the first electrode 81 and the second electrode 82 is provided on the element substrate 10 and the other is provided on the counter substrate 20. However, as shown in FIG. The present invention may be applied when both the second electrode 82 and the second electrode 82 are provided on the element substrate 10. Further, as shown in FIG. 10B, the present invention may be applied when both the first electrode 81 and the second electrode 82 are provided on the counter substrate 20. Further, in the form shown in FIGS. 10A and 10B, although not shown, the first electrode is formed on the substrate opposite to the substrate on which the first electrode 81 and the second electrode 82 are formed. 81 and the second electrode 82 may be provided, and a potential may be applied between the counter electrode and the first electrode 81 and between the counter electrode and the second electrode 82.

[Other embodiments]
In the above embodiment, the first electrode 81 and the second electrode 82 are formed on the entire circumference surrounding the image display region 10a. However, the first electrode 81 and the second electrode 82 are provided only at the two corners 10a ₁ and 10a ₃ positioned in the pretilt direction. A second electrode 82 may be provided. Moreover, in the said embodiment, although the 1st electrode 81 and the 2nd electrode 82 were provided one each, you may provide at least one of the 1st electrode 81 and the 2nd electrode 82 more than one.

  In the above embodiment, the present invention is applied to the transmissive liquid crystal device 100, but the present invention may be applied to the reflective liquid crystal device 100.

[Example of mounting on electronic devices]
An electronic apparatus to which the liquid crystal device 100 according to the above-described embodiment is applied will be described. FIG. 11 is a schematic configuration diagram of a projection display device using the liquid crystal device 100 to which the present invention is applied, and FIGS. 11A and 11B each show a projection display using the transmissive liquid crystal device 100. FIG. 2 is an explanatory diagram of the device and an explanatory diagram of a projection display device using the reflective liquid crystal device 100.

(First example of projection display device)
A projection display device 110 shown in FIG. 11A is a so-called projection-type projection display device that irradiates light onto a screen 111 provided on the viewer side and observes light reflected by the screen 111. . The projection display device 110 includes a light source unit 130 including a light source 112, dichroic mirrors 113 and 114, liquid crystal light valves 115 to 117 (liquid crystal device 100), a projection optical system 118, a cross dichroic prism 119, and a relay. System 120.

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

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

  The liquid crystal light valve 115 is a transmissive liquid crystal device 100 that modulates red light transmitted through the dichroic mirror 113 and reflected by the reflection mirror 123 in accordance with an image signal. The liquid crystal light valve 115 includes a λ / 2 phase difference plate 115a, a first polarizing plate 115b, a liquid crystal panel 115c, and a second polarizing plate 115d. Here, the red light incident on the liquid crystal light valve 115 remains s-polarized light because the polarization of the light does not change even if it passes through the dichroic mirror 113.

  The λ / 2 phase difference plate 115a is an optical element that converts s-polarized light incident on the liquid crystal light valve 115 into p-polarized light. The first polarizing plate 115b is a polarizing plate that blocks s-polarized light and transmits p-polarized light. The liquid crystal panel 115c is configured to convert p-polarized light into s-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to the image signal. Furthermore, the second polarizing plate 115d is a polarizing plate that blocks p-polarized light and transmits s-polarized light. Therefore, the liquid crystal light valve 115 is configured to modulate the red light according to the image signal and emit the modulated red light toward the cross dichroic prism 119.

  Note that the λ / 2 phase difference plate 115a and the first polarizing plate 115b are disposed in contact with a light-transmitting glass plate 115e that does not convert polarized light, and the λ / 2 phase difference plate 115a and the first polarizing plate 115b. It is possible to avoid distortion of 115b due to heat generation.

  The liquid crystal light valve 116 is a transmissive liquid crystal device 100 that modulates green light reflected by the dichroic mirror 114 after being reflected by the dichroic mirror 113 in accordance with an image signal. Similarly to the liquid crystal light valve 115, the liquid crystal light valve 116 includes a first polarizing plate 116b, a liquid crystal panel 116c, and a second polarizing plate 116d. Green light incident on the liquid crystal light valve 116 is s-polarized light that is reflected by the dichroic mirrors 113 and 114 and then incident. The first polarizing plate 116b is a polarizing plate that blocks p-polarized light and transmits s-polarized light. The liquid crystal panel 116c is configured to convert s-polarized light into p-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to the image signal. The second polarizing plate 116d is a polarizing plate that blocks s-polarized light and transmits p-polarized light. Accordingly, the liquid crystal light valve 116 is configured to modulate green light in accordance with the image signal and emit the modulated green light toward the cross dichroic prism 119.

  The liquid crystal light valve 117 is a transmissive liquid crystal device 100 that modulates blue light reflected by the dichroic mirror 113 and transmitted through the dichroic mirror 114 and then through the relay system 120 in accordance with an image signal. Similarly to the liquid crystal light valves 115 and 116, the liquid crystal light valve 117 includes a λ / 2 retardation film 117a, a first polarizing plate 117b, a liquid crystal panel 117c, and a second polarizing plate 117d. Here, since the blue light incident on the liquid crystal light valve 117 is reflected by the two reflecting mirrors 125a and 125b described later of the relay system 120 after being reflected by the dichroic mirror 113 and transmitted through the dichroic mirror 114, the s-polarized light is reflected. It has become.

  The λ / 2 phase difference plate 117a is an optical element that converts s-polarized light incident on the liquid crystal light valve 117 into p-polarized light. The first polarizing plate 117b is a polarizing plate that blocks s-polarized light and transmits p-polarized light. The liquid crystal panel 117c is configured to convert p-polarized light into s-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to the image signal. Furthermore, the second polarizing plate 117d is a polarizing plate that blocks p-polarized light and transmits s-polarized light. Accordingly, the liquid crystal light valve 117 is configured to modulate blue light in accordance with an image signal and emit the modulated blue light toward the cross dichroic prism 119. The λ / 2 phase difference plate 117a and the first polarizing plate 117b are disposed in contact with the glass plate 117e.

  The relay system 120 includes relay lenses 124a and 124b and reflection mirrors 125a and 125b. The relay lenses 124a and 124b are provided to prevent light loss due to a long blue light path. Here, the relay lens 124a is disposed between the dichroic mirror 114 and the reflection mirror 125a. The relay lens 124b is disposed between the reflection mirrors 125a and 125b. The reflection mirror 125a is disposed so as to reflect the blue light transmitted through the dichroic mirror 114 and emitted from the relay lens 124a toward the relay lens 124b. The reflection mirror 125b is arranged to reflect the blue light emitted from the relay lens 124b toward the liquid crystal light valve 117.

  The cross dichroic prism 119 is a color combining optical system in which two dichroic films 119a and 119b are arranged orthogonally in an X shape. The dichroic film 119a is a film that reflects blue light and transmits green light, and the dichroic film 119b is a film that reflects red light and transmits green light. Therefore, the cross dichroic prism 119 is configured to combine the red light, the green light, and the blue light modulated by the liquid crystal light valves 115 to 117 and emit the resultant light toward the projection optical system 118.

  Note that light incident on the cross dichroic prism 119 from the liquid crystal light valves 115 and 117 is s-polarized light, and light incident on the cross dichroic prism 119 from the liquid crystal light valve 116 is p-polarized light. Thus, by making the light incident on the cross dichroic prism 119 into different types of polarized light, the light incident from the liquid crystal light valves 115 to 117 in the cross dichroic prism 119 can be synthesized. Here, in general, the dichroic films 119a and 119b are excellent in s-polarized reflection transistor characteristics. Therefore, red light and blue light reflected by the dichroic films 119a and 119b are s-polarized light, and green light transmitted through the dichroic films 119a and 119b is p-polarized light. The projection optical system 118 has a projection lens (not shown) and is configured to project the light combined by the cross dichroic prism 119 onto the screen 111.

(Second example of projection display device)
A projection display device 1000 shown in FIG. 11B includes a light source unit 1021 that generates light source light and a color separation light guide optical that separates the light source light emitted from the light source unit 1021 into three colors of red, green, and blue. A system 1023 and a light modulation unit 1025 illuminated by the light source light of each color emitted from the color separation light guide optical system 1023 are provided. In addition, the projection display apparatus 1000 uses a cross dichroic prism 1027 (combining optical system) that combines the image light of each color emitted from the light modulation unit 1025 and the image light that has passed through the cross dichroic prism 1027 on a screen (not shown). A projection optical system 1029 which is a projection optical system for projecting.

  In the projection display apparatus 1000, the light source unit 1021 includes a light source 1021a, a pair of fly-eye optical systems 1021d and 1021e, a polarization conversion member 1021g, and a superimposing lens 1021i. In the present embodiment, the light source unit 1021 includes a reflector 1021f having a paraboloid and emits parallel light. The fly-eye optical systems 1021d and 1021e are composed of a plurality of element lenses arranged in a matrix in a plane orthogonal to the system optical axis, and the light source light is divided and condensed and diverged individually by these element lenses. The polarization conversion member 1021g converts the light source light emitted from the fly-eye optical system 1021e into, for example, only a p-polarized component parallel to the drawing, and supplies it to the optical path downstream optical system. The superimposing lens 1021i allows the plurality of liquid crystal devices 100 provided in the light modulation unit 1025 to uniformly illuminate each other by appropriately converging the light source light that has passed through the polarization conversion member 1021g as a whole.

  The color separation light guide optical system 1023 includes a cross dichroic mirror 1023a, a dichroic mirror 1023b, and reflection mirrors 1023j and 1023k. In the color separation light guide optical system 1023, the substantially white light source light from the light source unit 1021 enters the cross dichroic mirror 1023a. The red (R) light reflected by one of the first dichroic mirrors 1031a constituting the cross dichroic mirror 1023a is reflected by the reflecting mirror 1023j, passes through the dichroic mirror 1023b, and passes through the incident side polarizing plate 1037r and the p-polarized light. Then, the light is incident on the red (R) liquid crystal device 100 as p-polarized light through the wire grid polarizer 1032r that reflects s-polarized light and the optical compensation plate 1039r.

  Further, the green (G) light reflected by the first dichroic mirror 1031a is reflected by the reflection mirror 1023j, and then also reflected by the dichroic mirror 1023b to transmit the incident side polarizing plate 1037g and p-polarized light, and s-polarized light. Is incident on the green (G) liquid crystal device 100 as p-polarized light through the wire grid polarizing plate 1032g and the optical compensation plate 1039g.

  On the other hand, the blue (B) light reflected by the other second dichroic mirror 1031b constituting the cross dichroic mirror 1023a is reflected by the reflection mirror 1023k and passes through the incident side polarizing plate 1037b and the p-polarized light. On the other hand, it enters the liquid crystal device 100 for blue (B) as p-polarized light through the wire grid polarizing plate 1032b that reflects s-polarized light and the optical compensation plate 1039b. Note that the optical compensation plates 1039r, 1039g, and 1039b optically compensate the characteristics of the liquid crystal layer by adjusting the polarization states of the incident light and the emitted light to the liquid crystal device 100.

  In the projection display apparatus 1000 configured as described above, the three colors of light incident through the optical compensation plates 1039r, 1039g, and 1039b are modulated in the liquid crystal devices 100, respectively. At that time, of the modulated light emitted from the liquid crystal device 100, the s-polarized component light is reflected by the wire grid polarizing plates 1032r, 1032g, and 1032b, and crossed dichroic prisms via the outgoing-side polarizing plates 1038r, 1038g, and 1038b. Incident at 1027. In the cross dichroic prism 1027, a first dielectric multilayer film 1027a and a second dielectric multilayer film 1027b intersecting in an X shape are formed, and the first dielectric multilayer film 1027a reflects R light, The other second dielectric multilayer film 1027b reflects B light. Therefore, the three colors of light are combined by the cross dichroic prism 1027 and emitted to the projection optical system 1029. The projection optical system 1029 projects the color image light synthesized by the cross dichroic prism 1027 on a screen (not shown) at a desired magnification.

(Other projection display devices)
In addition, about a projection type display apparatus, you may comprise the LED light source etc. which radiate | emit the light of each color as a light source part, and supply each color light radiate | emitted from this LED light source to another liquid crystal device. .

(Other electronic devices)
As for the liquid crystal device 100 to which the present invention is applied, in addition to the electronic devices described above, mobile phones, personal digital assistants (PDAs), digital cameras, liquid crystal televisions, car navigation devices, video phones, POS terminals, You may use as a direct view type | mold display apparatus in electronic devices, such as an apparatus provided with the touch panel.

9a ... Pixel electrode, 9b ... Dummy pixel electrode, 10 ... Element substrate, 10a ... Image display area, 10b ... Peripheral area, 20 ... Counter substrate, 21 ... Common electrode, 50 ... Liquid crystal layer, 81..First electrode 82..Second electrode 107..Sealant 100..Liquid crystal device 110, 1000..Projection type display device

Claims (10)

An element substrate provided with a pixel electrode and an alignment film in an image display region;
A counter substrate provided with a common electrode and an alignment film in the image display region;
A sealing material for bonding the element substrate and the counter substrate;
A liquid crystal layer held in a region surrounded by the sealing material between the element substrate and the counter substrate;
A first electrode provided in a region sandwiched between the image display region and the sealing material of at least one of the element substrate and the counter substrate;
A second electrode that is provided in a region sandwiched between the image display region and the sealing material of at least one of the element substrate and the counter substrate, and to which a potential different from that of the first electrode is applied;
Have
At least one of the first electrode and the second electrode includes a conductive layer and a charge injection layer that is stacked on the side where the liquid crystal layer is located with respect to the conductive layer and is in contact with the liquid crystal layer. A liquid crystal device comprising: The first electrode is provided on one of the element substrate and the counter substrate,
The liquid crystal device according to claim 1, wherein the second electrode is provided on the other of the element substrate and the counter substrate. The first electrode includes a first conductive layer as the conductive layer, and as the charge injection layer, a first barrier that lowers an energy barrier when electrons move from the first conductive layer to the liquid crystal layer side. One charge injection layer,
The second electrode includes a second conductive layer as the conductive layer, and as the charge injection layer, the second electrode lowers an energy barrier when electrons move from the liquid crystal layer side to the second conductive layer. The liquid crystal device according to claim 1, further comprising a two-charge injection layer. The first charge injection layer is one of a hydroxyquinoline-aluminum complex, an azomethine-zinc complex, and a distyrylbiphenyl derivative;
The liquid crystal device according to claim 3, wherein the second charge injection layer is one of a phthalocyanine compound, a triallylamine compound, a perylene compound, and a europium complex.   5. The DC voltage having a higher potential on the second electrode side than on the first electrode side is applied between the first electrode and the second electrode. 6. Liquid crystal device.   5. The liquid crystal device according to claim 3, wherein an alternating voltage is applied between the first electrode and the second electrode.   Since the alignment film is not formed in a region overlapping the charge injection layer on the liquid crystal layer side, the charge injection layer is exposed from the alignment film and is in contact with the liquid crystal layer. The liquid crystal device according to claim 1, wherein the liquid crystal device is a liquid crystal device.   In the region overlapping the charge injection layer on the liquid crystal layer side, the alignment film is formed as an inorganic alignment film composed of a plurality of protrusions, so that the charge injection layer is interposed between the protrusions. The liquid crystal device according to claim 1, wherein the liquid crystal device is exposed from the alignment film and is in contact with the liquid crystal layer. A projection display device comprising the liquid crystal device according to any one of claims 1 to 8,
A light source unit for emitting light supplied to the liquid crystal device;
A projection optical system for projecting light modulated by the liquid crystal device;
A projection display device characterized by comprising:   An electronic apparatus comprising the liquid crystal device according to any one of claims 1 to 8.

Images