JP2007017824A - Electro-optical device, and electronic appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device in which occurrence of display unevenness is prevented by making layer thickness of an electro-optical material layer, such as a liquid crystal layer, fixed. <P>SOLUTION: A liquid crystal display device has a TFD element 21 mounted on an element substrate 11; an interlayer insulating film 22 formed on the TFD element 21 and having a contact hole 25 in the inside; a pixel electrode 24a formed on the interlayer insulating film 22 and connected to the TFD element 21 via the contact hole 25; a color filter substrate 12 arranged so as to be face the element substrate 11; and an overcoat layer 33 disposed on a surface of the color filter substrate 12 facing the element substrate 11. The overcoat layer 33 is formed, in such a way that the thickness t1 of a region V0, overlapping with the TFD element 21 in plan view, is made thinner than thickness t2 of a region in its periphery. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electro-optical device such as a liquid crystal display device. The present invention also relates to an electronic apparatus configured using the electro-optical device.

  Currently, electro-optical devices are widely used in various electronic devices such as mobile phones and portable information terminals. For example, an electro-optical device is used as a display unit for visually displaying various types of information related to electronic devices. In this electro-optical device, a device using liquid crystal as an electro-optical material, that is, a liquid crystal display device is known.

  A liquid crystal display device having an insulating layer is known. As such an insulating layer, for example, on a substrate constituting the liquid crystal display device, a switching element such as a TFT (Thin Film Transistor) element or a layer provided with wiring and a layer provided with a pixel electrode are separated. (For example, refer to Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-111899 (page 4, FIG. 1)

  However, when observing the sub-pixel region, which is the minimum unit of display, the region where the switching element is provided has a surface height of the insulating layer that is higher than the surrounding region by the thickness of the switching element. As a result, it is conceivable that the thickness of the liquid crystal layer is reduced. As described above, when the layer thickness of the liquid crystal layer becomes non-uniform in the sub-pixel region, there is a possibility that the display of the liquid crystal display device may be uneven.

  The present invention has been made in view of the above problems, and even when there is a partial protruding region on the substrate because of the switching element, the thickness of the electro-optical material layer such as a liquid crystal layer is reduced. An object of the present invention is to provide an electro-optical device and an electronic apparatus that can prevent the occurrence of unevenness in display by keeping the display constant.

  The electro-optical device according to the present invention includes a substrate, a switching element provided on the substrate, an insulating layer formed on the switching element, and formed on the insulating layer and provided on the insulating layer. A reflection electrode connected to the switching element through a contact hole; a counter substrate provided opposite to the substrate; and a resin layer provided on a surface of the counter substrate facing the substrate; A thickness of the resin layer in a region overlapping with the element in a plane is smaller than a thickness of a peripheral region.

  Examples of the switching element include a TFT element in which a semiconductor layer is sandwiched between a plurality of electrodes, and a TFD (Thin Film Diode) element in which an insulating film is sandwiched between a pair of electrodes. In addition, the region overlapping the switching element in a plan view may be a region overlapping the entire switching element or a region overlapping a part of the switching element.

  In the electro-optical device according to the present invention described above, the thickness of the resin layer in the region overlapping the switching element in a plan view is formed thinner than the peripheral region. Thereby, even if the surface height of the insulating layer is increased by the thickness of the switching element in the region where the switching element is provided, it is possible to prevent the electro-optical material layer from being thinned. Accordingly, the thickness of the electro-optical material layer can be made uniform. As a result, when display is performed in an effective display area formed by a set of a plurality of sub-pixel areas, it is possible to prevent display unevenness from occurring in the effective display area in which the switching element is provided. .

  Next, in the electro-optical device according to the aspect of the invention, it is preferable that the reflective electrode is formed by a single layer of a light-reflective and conductive material or a stacked layer of a light-reflecting film and a pixel electrode. This electro-optical device is a so-called reflective display device or transflective display device. A reflective display device is a device that performs display by reflecting the entire area of a sub-pixel region, which is the minimum unit of display, as a reflective display region and reflecting external light or the like through the reflective display region. On the other hand, the transflective device is a display device that can provide both reflective display and transmissive display by providing both a reflective display region and a transmissive display region in a sub-pixel region.

  As an aspect of providing the reflective electrode on the substrate, (1) In the transflective display device, a light reflective film is provided in the reflective display region, and light transmittance is provided over the entire reflective display region and transmissive display region. A configuration in which a pixel electrode is provided, or (2) a transflective display device in which a pixel electrode is formed of a light reflective material in a reflective display region and a pixel electrode having light transmittance is formed in a transmissive display region; (3) In a reflective display device, a configuration in which pixel electrodes are formed in the entire sub-pixel region with a light-reflective material is conceivable. In these reflective display areas, a switching element is provided so as to overlap the pixel electrode or the light reflecting film formed of the light reflecting material in a plane. Therefore, it is conceivable that the electro-optic material layer is thinned by the thickness of the switching element in the reflective display area and in the area overlapping the switching element in a plane.

  If the present invention is applied to the electro-optical device having the reflective display area as described above, the thickness of the resin layer in the area overlapping the switching element in the reflective display area is made thinner than the surrounding area. Therefore, even if the height of the surface of the insulating layer is increased by the thickness of the switching element in a region overlapping with the switching element, it is possible to prevent the electro-optic material layer from being thinned. Accordingly, the thickness of the electro-optical material layer can be made uniform. As a result, when display is performed in an effective display area formed by a set of a plurality of sub-pixel areas, it is possible to prevent display unevenness from occurring in the effective display area in which the switching element is provided. .

  Next, the electro-optical device according to the aspect of the invention preferably further includes a coloring element on the counter substrate on the side facing the substrate, and the resin layer is an overcoat layer that covers the coloring element. This overcoat layer is formed, for example, by patterning a photosensitive resin into a predetermined shape by photolithography. When this overcoat layer is used as the resin layer, it is possible to reduce the thickness of the overcoat layer in a region that overlaps with the active element in a plane simultaneously with the patterning of the overcoat layer.

  Next, in the electro-optical device according to the aspect of the invention, it is preferable that the region where the resin layer is formed thin is a region that covers the entire switching element in a planar manner. The area covering the entire switching element in plan view is (1) an area including both the entire element portion and an electrode extending therefrom (for example, FIG. 9 (a), FIG. 10 (a)), or (2) element A region including the end portion of the main body portion to the terminal connected to the pixel electrode (for example, FIG. 9B and FIG. 10B) can be considered. Further, the region covering the entirety of these switching elements may be a region covered with a square when seen in a plan view, or may be a curved shape roughly according to the outer shape of the switching element. As described above, if the thickness of the resin layer corresponding to the region covering the entire switching element is thin, the electro-optic material layer is formed over the entire region where the height of the surface of the insulating layer is increased by the switching element. The layer thickness can be kept constant.

  Next, in the electro-optical device according to the aspect of the invention, it is preferable that the region where the resin layer is thinly formed is a region that covers at least the highest part of the switching element in a planar manner. The thickest region of the switching element is a region where the constituent elements of the switching device are stacked and thickened, and is considered to be a region having the largest number of layers, for example. This region is the portion where the change in the thickness of the electro-optic material layer is the largest. If the resin layer in this region is formed thin, the thickness of the electro-optic material layer can be reliably maintained constant.

  Next, in the electro-optical device according to the aspect of the invention, it is preferable that the switching element is a TFD element in which an insulating film is sandwiched between a pair of electrodes. In this case, the surface height of the insulating layer is increased by the thickness of the TFD element in the region where the TFD element is provided. When the present invention is applied to the electro-optical device having such a configuration, the thickness of the region overlapping the TFD element is made thinner than the surrounding region, so that the thickness of the electro-optical material layer is reduced. Can be prevented. Accordingly, the thickness of the electro-optical material layer can be made uniform. As a result, when display is performed in an effective display area formed by a set of a plurality of sub-pixel areas, it is possible to prevent unevenness in display in the area where the TFD element is provided in the effective display area. .

  Next, in the electro-optical device according to the invention, it is desirable that the switching element is a TFT element having a semiconductor layer sandwiched between a plurality of electrodes. In this case, in the region where the TFT element is provided, the height of the surface of the insulating layer is increased by the thickness of the TFT element. When the present invention is applied to the electro-optical device having such a configuration, the thickness of the electro-optic material layer is reduced by forming the thickness of the region overlapping the TFT element in a plane smaller than that of the surrounding region. Can be prevented. Accordingly, the thickness of the electro-optical material layer can be made uniform. As a result, when display is performed in an effective display area formed by a set of a plurality of sub-pixel areas, it is possible to prevent display unevenness from occurring in an area where TFT elements are provided in the effective display area. .

  Next, an electronic apparatus according to the present invention includes the electro-optical device having the above-described configuration. In the electro-optical device according to the present invention, the thickness of the resin layer in the region that overlaps the switching element in a planar manner is made thinner than the peripheral region, thereby making the layer thickness of the electro-optical material layer non-uniform. Therefore, unevenness in display can be prevented. Accordingly, even in an electronic apparatus using the electro-optical device according to the present invention, it is possible to prevent unevenness in displaying information related to the electronic apparatus performed using the electro-optical device.

(First embodiment of electro-optical device)
Hereinafter, an electro-optical device according to the invention will be described based on embodiments. Of course, the present invention is not limited to this embodiment. Further, in the drawings used in the following description, components may be illustrated with a dimensional ratio different from an actual dimensional ratio in order to easily show a feature portion.

  FIG. 1 shows a liquid crystal display device which is an embodiment of an electro-optical device according to the present invention. 2 is a cross-sectional view taken along the line BB in FIG. FIG. 3 shows an enlarged view of the pixel portion indicated by arrow C in FIG. 4 is an enlarged plan view showing the pixel portion from the direction of arrow A in FIG. In this embodiment, the present invention is applied to an active matrix type liquid crystal display device using a two-terminal switching element or a TFD (Thin Film Diode) element which is an active element as a switching element.

  In FIG. 1, a liquid crystal display device 1 includes a liquid crystal panel 2 as an electro-optical panel, an illumination device 3 attached to the liquid crystal panel 2, and an FPC (Flexible Printed Circuit: FPC) as a wiring board connected to the liquid crystal panel 2. Flexible printed circuit board) 4. Regarding the liquid crystal display device 1, the side on which the arrow A is drawn is the observation side, and the illumination device 3 is disposed on the opposite side to the observation side with respect to the liquid crystal panel 2 and functions as a backlight.

  The liquid crystal panel 2 includes a pair of substrates 11 and 12 that are bonded to each other by a rectangular or square annular sealing material 5 when viewed from the observation side on which an arrow A is drawn. These substrates 11 and 12 are both formed in a rectangle or a square when viewed from the direction of arrow A. The substrate 11 is an element substrate on which switching elements are formed. The substrate 12 is a counter substrate with respect to the substrate 11 and is a color filter substrate on which a color filter is formed.

  As shown in FIG. 2, the sealing material 5 forms a gap, so-called cell gap G, between the element substrate 11 and the color filter substrate 12. As shown in FIG. 1, the sealing material 5 has a liquid crystal inlet 5a in a part thereof, and a liquid crystal as an electro-optical material is interposed between the element substrate 11 and the color filter substrate 12 through the liquid crystal inlet 5a. Is injected. The injected liquid crystal forms a liquid crystal layer 10 within the cell gap G as shown in FIG. The liquid crystal injection port 5a in FIG. 1 is sealed with resin after the liquid crystal injection is completed. As a method for injecting liquid crystal, a method of supplying liquid crystal droplets into a region surrounded by a continuous annular sealing material 5 having no liquid crystal injection port is employed in addition to the method of performing through the liquid crystal injection port 5a as described above. it can.

  The interval between the cell gaps G shown in FIG. 2, that is, the layer thickness of the liquid crystal layer 10 is maintained constant by a plurality of spacers (not shown) provided in the cell gap G. This spacer can be formed by placing a plurality of spherical resin members randomly (ie, disorderly) on the surface of the element substrate 11 or the color filter substrate 12. The spacer can also be formed in a columnar shape at a predetermined position by photolithography.

  In FIG. 1, an illuminating device 3 includes a light source, specifically, an LED (Light Emitting Diode) 6 as a point light source, and a light guide that converts the point light emitted from the LED 6 into a planar shape and emits the light. 7. The light guide 7 is formed of, for example, a light transmissive resin. Each of the LEDs 6 is provided in a plurality, three in the present embodiment, and the light emitting surfaces thereof are provided so as to face the light incident surface 7 a that is one side surface of the light guide 7. Light emitted from each LED 6 is introduced from the light incident surface 7 a into the light guide 7, emitted from the light exit surface 7 b of the light guide 7 as planar light, and supplied to the liquid crystal panel 2. In addition, the light-diffusion layer 8 is provided in the light-projection surface 7b of the light guide 7 as needed. Further, a light reflecting layer 9 is provided on the surface of the light guide 7 opposite to the light emitting surface 7b as necessary. The light source can also be constituted by a point light source other than the LED 6 or a linear light source such as a cold cathode tube.

  The element substrate 11 includes a first light-transmitting substrate 11a in FIG. The first translucent substrate 11a is formed of, for example, translucent glass, translucent plastic, or the like. A polarizing plate 13a is attached to the outer surface of the first translucent substrate 11a by, for example, sticking. If necessary, an optical element other than the polarizing plate 13a, such as a retardation plate, may be additionally provided. On the other hand, on the inner surface of the first translucent substrate 11a, a plurality of data lines 14 are formed in parallel to each other in the direction perpendicular to the paper surface (that is, the row direction X in FIG. 1). Each data line 14 extends in the left-right direction in FIG. 2 (that is, the column direction Y in FIG. 1). A plurality of TFD elements 21 as switching elements functioning as switching elements are formed along the data lines 14 and connected to the data lines 14.

  As shown in FIG. 3, an interlayer insulating film 22 as an insulating layer is formed on the TFD elements 21 and the data lines 14 so as to cover them, and a light reflecting film 23 is formed thereon. A pixel electrode 24a is formed thereon, and an alignment film 26a is formed thereon. The interlayer insulating film 22 is formed, for example, by patterning a resin having translucency, photosensitivity, and insulation, such as an acrylic resin or a polyimide resin, by a photolithography process. The light reflecting film 23 is formed by patterning a light reflecting material such as Al (aluminum) or an Al alloy by a photoetching process. The pixel electrode 24a is formed by patterning a metal oxide such as ITO (Indium Tin Oxide) by a photoetching process. The alignment film 26a is formed, for example, by applying polyimide or the like. In the present embodiment, the reflective electrode is formed by two layers of the light reflective film 23 and the pixel electrode 24a.

  As shown in FIG. 1, a plurality of light reflecting films 23 and pixel electrodes 24 a are formed in a dot matrix on the element substrate 11. The light reflecting film 23 and the pixel electrode 24 a are connected to the individual TFD elements 21 and are provided along the data lines 14. The plurality of pixel electrodes 24a are individually formed in a dot shape as illustrated, and are formed so as to be arranged in a matrix in the vertical and horizontal directions, that is, in the matrix (XY) direction. The alignment film 26a in FIG. 3 is formed over substantially the entire surface of the element substrate 11. The alignment film 26a is subjected to an alignment process, for example, a rubbing process, whereby the initial alignment of liquid crystal molecules in the vicinity of the element substrate 11 is determined.

  In FIG. 3, a contact hole 25 for electrically connecting the light reflecting film 23 and the TFD element 21 is formed in the interlayer insulating film 22. The contact hole 25 is formed at the same time when the interlayer insulating film 22 is formed by photolithography. The contact hole 25 is formed at a position that does not overlap with the TFD element 21 in a plan view, that is, in a plan view, and that overlaps with the light reflection film 23.

  In the present embodiment, the TFD element 21 is formed by a pair of TFD elements 21a and 21b that are electrically connected to each other in series. The first TFD element 21a is formed by stacking a first element electrode 27, an insulating film 28, and a second element electrode 29a in that order. The second TFD element 21b is formed by overlapping the first element electrode 27, the insulating film 28, and the second element electrode 29b in that order. The first element electrode 27 is made of, for example, Ta (tantalum) or Ta alloy. As the Ta alloy, for example, TaW (tantalum / tungsten) can be used. The insulating film 28 is formed by, for example, an anodic oxidation process. The second element electrodes 29a and 29b are made of, for example, Cr (chromium) or MoW (molybdenum / tungsten) alloy.

  The second element electrode 29 a in the first TFD element 21 a extends from the data line 14. The second element electrode 29b in the second TFD element 21b is connected to the pixel electrode 24a through the contact hole 25 and the light reflecting film 23. Considering that a signal is transmitted from the data line 14 to the pixel electrode 24a, the first TFD element 21a and the second TFD element 21b are connected in series with two TFD elements having opposite polarities. This structure is sometimes referred to as a back-to-back structure. In this embodiment, the back-to-back structure TFD element is used as described above. However, the TFD element may be formed by a single TFD element.

  In this embodiment, by providing the interlayer insulating film 22 under the pixel electrode 24a, the layer of the pixel electrode 24a and the layer of the TFD element 21 are separated into different layers. This structure makes it possible to effectively use the surface of the element substrate 11 as compared with a structure in which the pixel electrode 24a and the TFD element 21 are formed in the same layer. For example, the area of the pixel electrode 24a, that is, the pixel area can be increased, so that the display can be easily viewed in the liquid crystal display device 1.

  In FIG. 2, the color filter substrate 12 facing the element substrate 11 includes a second light-transmitting substrate 12 a that is rectangular or square when viewed from the observation side indicated by an arrow A. The second translucent substrate 12a is formed of, for example, translucent glass or translucent plastic. A polarizing plate 13b is attached to the outer surface of the second light transmissive substrate 12a, for example, by sticking. If necessary, an optical element other than the polarizing plate 13b, for example, a retardation plate, may be additionally provided.

  As shown in FIG. 3, a coloring element 31 is formed on the inner surface of the second translucent substrate 12 a, a light shielding member 32 is formed around the coloring element 31, and a resin layer is formed on the coloring element 31 and the light shielding member 32. The overcoat layer 33 is formed, the strip electrode 24b is formed thereon, and the alignment film 26b is formed thereon. The strip electrode 24b extends in the direction perpendicular to the paper surface of FIG. 3 (that is, the row direction X). The alignment film 26b is formed by applying polyimide or the like, for example.

  The coloring element 31 is formed in a rectangular or square dot shape when viewed from the direction of the arrow A. A plurality of the coloring elements 31 are arranged in a matrix in the row direction X (perpendicular to the plane of FIG. 3) and the column direction Y (lateral direction in FIG. 3) when viewed from the direction of arrow A. The light shielding member 32 is formed in a lattice shape surrounding the coloring elements 31. Each of the coloring elements 31 is set to an optical characteristic that allows one of B (blue), G (green), and R (red) to pass therethrough, and the coloring elements 31 of B, G, and R are viewed from the direction of the arrow A. They are arranged in a predetermined arrangement, for example, a stripe arrangement. The stripe arrangement is an arrangement in which the same colors B, G, and R are arranged in the column direction Y, and B, G, and R are arranged alternately in the row direction X.

  Note that the arrangement of the coloring elements 31 can be any arrangement other than the stripe arrangement, for example, a mosaic arrangement, a delta arrangement, or the like. Further, the optical characteristics of the coloring element 31 are not limited to the three primary colors B, G, and R, and may be a characteristic that allows the three primary colors C (cyan), M (magenta), and Y (yellow) to pass. In the present embodiment, the light shielding member 32 is formed by overlapping any two of the three primary colors B, G, and R. However, the light shielding member 32 can be formed by overlapping three colors of B, G, and R, or can be formed by patterning a predetermined material by photolithography. As the predetermined material in this case, for example, a light shielding material such as Cr can be considered.

  The overcoat layer 33 formed on the coloring element 31 and the light shielding member 32 is for flattening the surfaces of the coloring element 31 and the light shielding member 32, and the strip electrode 24 b is formed by the overcoat layer 33 thus planarized. Formed on top. The strip electrode 24b is formed by patterning a metal oxide such as ITO, for example, by a photoetching process. As shown in FIG. 1, a plurality of strip electrodes 24b are provided on the color filter substrate 12 so as to be arranged in parallel to each other. Each strip-like electrode 24b extends in the row direction X. In FIG. 3, the alignment film 26b formed on the strip electrode 24b is subjected to an alignment process, for example, a rubbing process, whereby the initial alignment of liquid crystal molecules in the vicinity of the color filter substrate 12 is determined.

  In FIG. 2, the plurality of pixel electrodes 24 a provided on the element substrate 11 are arranged in a matrix in the row direction X and the column direction Y as seen in a plan view from the arrow A direction. On the other hand, the plurality of strip-like electrodes 24b provided on the color filter substrate 12 are arranged in stripes so as to overlap with the plurality of pixel electrodes 24a arranged in the row direction X when viewed in a plane from the arrow A direction. Thus, the pixel electrode 24a and the strip electrode 24b overlap each other when viewed from the direction of the arrow A, and the overlapped region forms a sub-pixel region D which is a minimum unit for display. A plurality of sub-pixel areas D are arranged in a matrix in the row direction X and the column direction Y to form the display area V in FIG. 1, and images such as characters, numbers, figures, etc. are displayed in the display area V. .

  When color display is performed using the coloring elements 31 composed of the three colors B, G, and R as in the present embodiment, 3 corresponding to the three coloring elements 31 corresponding to the three colors B, G, and R One pixel is formed by one sub-pixel region D. On the other hand, when monochrome display is performed in black and white or any two colors, one pixel is formed by one sub-pixel region D. As shown in FIG. 4, which is a plan view showing one pixel portion, the sub-pixel D is formed in a rectangular shape.

  In FIG. 3, which is a cross-sectional view taken along line EE in FIG. 4, the light reflecting film 23 is formed by, for example, a photo etching process. The light reflecting film 23 is provided in a part of the sub-pixel region D, and is not provided in the remaining region T. As shown in FIG. 4, the region R is a part of the rectangular region in the sub-pixel region D, and the region T is the remaining rectangular region in the sub-pixel region D.

  In each sub-pixel region D, a region where the light reflecting film 23 exists is a reflective display region R, and a region T where the light reflecting film 23 does not exist is a transmissive display region. In FIG. 3, the external light L0 incident from the observation side indicated by the arrow A is reflected by the reflective display region R. On the other hand, the light L1 in FIG. 3 emitted from the light guide 7 of the illumination device 3 in FIG.

  Convex portions or concave portions are formed on the surface of the interlayer insulating film 22 and corresponding to the reflective display region R in each sub-pixel region D to form a concave / convex pattern. This concavo-convex pattern is a random (that is, disordered) pattern as viewed from the direction of arrow A. The light reflecting film 23 is formed on the interlayer insulating film 22 on which such a concavo-convex pattern is formed, and itself has the same concavo-convex pattern. By forming the uneven pattern on the light reflecting film 23 in this way, the light L0 reflected by the light reflecting film 23 can be not a specular reflection but a light having scattered light or directivity.

  The light shielding member 32 formed around the coloring element 31 in the color filter substrate 12 is formed so as to surround the periphery of the sub-pixel D as indicated by a chain line in FIG. The light blocking member 32 prevents light from leaking from the periphery of the sub-pixel D and improves display contrast.

  Next, in FIG. 2, the first translucent substrate 11 a constituting the element substrate 11 has an overhanging portion 34 that protrudes to the outside of the color filter substrate 12. A wiring 35 is formed on the surface of the overhang portion 34 by a photo etching process or the like. A plurality of wirings 35 are formed as viewed from the direction of arrow A, and the plurality of wirings 35 are arranged in parallel at equal intervals in the direction perpendicular to the paper surface. Further, a plurality of external connection terminals 36 are formed at the side edges of the overhang portion 34 so as to be arranged in parallel to each other at equal intervals in the direction perpendicular to the paper surface. The wiring formed on the FPC board 4 shown in FIG. 1 is conductively connected to the external connection terminal 36 shown in FIG.

  Some of the plurality of wirings 35 serve as data lines 14 and extend on the surface of the first light transmitting substrate 11a. Further, the remaining part of the plurality of wirings 35 is electrically connected to a strip electrode 24b provided on the color filter base 12 through a conductive material 37 included randomly (that is, disorderly) in the seal material 5. Yes. Although the conductive material 37 is schematically drawn large in FIG. 2, the conductive material 37 is actually smaller than the width of the cross section of the seal material 5, and a plurality of conductive materials 37 are included in one cross section of the seal material 5. Usually included.

  A driving IC 39 is mounted on the surface of the overhang portion 34 by COG (Chip On Glass) technology using an ACF (Anisotropic Conductive Film) 38. In this embodiment, a plurality of, for example, three drive ICs 39 are mounted as shown in FIG. For example, one driving IC 39 in the center transmits a data signal to the data line 14. On the other hand, the driving ICs 39 on both sides transmit the scanning signal to the strip-like electrode 24b formed on the color filter substrate 12.

  According to the liquid crystal display device 1 configured as described above, when the liquid crystal display device 1 is placed outdoors or in a bright room, a reflective display is performed using external light such as sunlight or room light. . On the other hand, when the liquid crystal display device 1 is placed outside a dark room or in a dark room, a transmissive display is performed using the lighting device 3 as a backlight.

  In the case of performing the reflective display, the external light L0 that has entered the liquid crystal panel 2 through the color filter substrate 12 from the direction of the arrow A on the observation side in FIG. 3 passes through the liquid crystal layer 10 and enters the element substrate 11. Then, the light is reflected by the light reflection film 23 in the reflective display region R and supplied to the liquid crystal layer 10 again. On the other hand, when performing the transmissive display described above, the LED 6 of the illumination device 3 in FIG. 2 is turned on, and light from the LED 6 is introduced from the light incident surface 7a of the light guide 7 to the light guide 7, and further, the light exit surface. 7b is emitted as planar light. The emitted light is supplied to the liquid crystal layer 10 through a region where the light reflection film 23 does not exist in the transmissive display region T as indicated by a symbol L1 in FIG.

  While light is supplied to the liquid crystal layer 10 as described above, a predetermined distance specified by the scanning signal and the data signal is provided between the pixel electrode 24a on the element substrate 11 side and the strip electrode 24b on the color filter substrate 12 side. Thus, the orientation of the liquid crystal molecules in the liquid crystal layer 10 is controlled for each sub-pixel region D. As a result, the light supplied to the liquid crystal layer 10 is modulated for each sub-pixel region D. When the modulated light passes through the polarizing plate 13b (see FIG. 2) on the color filter substrate 12 side, the passage is allowed or blocked for each sub-pixel region D according to the polarization characteristics of the polarizing plate 13b. Thus, an image such as letters, numbers, figures, etc. is displayed on the surface of the color filter substrate 12, and this is visually recognized from the arrow A direction.

  FIG. 5 shows an enlarged view of the portion indicated by arrow F in FIG. 3, that is, the portion where the TFD element 21 is formed. In FIG. 5, the overcoat layer 33 is formed on the color filter substrate 12 and on the coloring element 31 and the light shielding member 32. The TFD element 21 is formed on the inner surface of the element substrate 11 facing the color filter substrate 12. In the planar region in which the pixel electrode 24a is provided, that is, in the sub-pixel region D, the overcoat layer 33 has a layer thickness t1 in the region V0 that planarly overlaps the TFD element 21 compared to the layer thickness t2 in the surrounding region. Thinly formed.

  In the present embodiment, the region V0 that overlaps the TFD element 21 in a plan view is a region that includes at least the width W0 of the TFD element 21 as viewed in the cross section shown in FIG. Specifically, this is a region including the end of one second element electrode 29a to the end of the other second element electrode 29b. On the other hand, this region V0 surrounds the entire TFD element 21 connected to the data line 14 along the outline of the TFD element 21 when viewed in a plan view as shown in an enlarged manner by the arrow H in FIG. It is a curved area.

  In FIG. 5, the layer thickness t1 of the overcoat layer 33 in the region V0 is determined by the thickness of the TFD element 21 (that is, the height from the surface of the first translucent substrate 11a) t0. Specifically, it is formed thinner than the layer thickness t2 of the overcoat layer 33 in the peripheral region of the region V0 by the thickness t0 of the TFD element 21. The TFD element 21 is formed by laminating the first element electrode 27, the insulating film 28, and the second element electrodes 29a and 29b as described above, and the thickness thereof can be seen from FIG. However, the entire TFD element 21 is not constant. Therefore, in the present embodiment, the thickness t0 of the TFD element 21 is set to an average thickness in the entire TFD element 21.

  Specifically, the thickness t3 of the thinnest portion (that is, the portion where only the second element electrodes 29a and 29b are formed) and the thickest portion (that is, the first element electrode 27, the insulating film 28, and the second element). This is the average thickness with the thickness t4 of the portion where the electrodes 29a and 29b are laminated. For example, when the first element electrode 27 is formed with Ta to a thickness of about 1000 mm, the insulating film 28 is formed with TaOx to a thickness of about 1000 mm, and the second element electrodes 29a and 29b are formed with Cr to 1600 mm, the TFD The thickness t0 of the element 21 can be about 1200 mm, which is the average of them. FIG. 5 illustrates a case where the thickness t0 of the TFD element 21 serving as a reference for determining the layer thickness t1 of the overcoat layer 33 is the thickest thickness t4.

  By the way, in the interlayer insulating film 22 formed on the element substrate 11, the height h1 in the region V0 that planarly overlaps the TFD element 21 is higher than the height h2 in the peripheral region. The difference between the height h1 and the height h2 is substantially equal to the thickness t0 of the TFD element 21 described above. As a result, the light reflecting film 23, the pixel electrode 24a, and the alignment film 26a formed on the interlayer insulating film 22 are also formed higher by the thickness t0 of the TFD element 21 in the region V0. Here, considering the conventional liquid crystal display device in which the thickness of the overcoat layer 33 in the region V0 shown in FIG. 5 is not thinned, the surface of the alignment film is formed high in the region on the TFD element. In the upper region, it is conceivable that the layer thickness of the liquid crystal layer, that is, the cell gap becomes thinner than the other regions in the sub-pixel region. When the cell gap becomes non-uniform in the sub-pixel region as described above, there is a possibility that the display of the liquid crystal display device becomes uneven.

  On the other hand, according to the liquid crystal display device 1 of the present embodiment in which the overcoat layer 33 is thinly formed in the region V0, the thickness T0 of the TFD element 21 in the region V0 where the TFD element 21 is provided. Even if the height h1 of the surface of the interlayer insulating film 22 is increased, the thickness of the liquid crystal layer 10, that is, the cell gap G can be prevented from being reduced. That is, in the sub-pixel region D, the cell gap G0 in the region V0 and the cell gap G1 in other regions can be made uniform. As a result, display unevenness can be prevented from occurring in the region Vo where the TFD element 21 is provided.

(Second embodiment of electro-optical device)
Next, another embodiment of the electro-optical device according to the invention will be described with reference to FIGS. Of course, the present invention is not limited to the embodiment. Further, the structures shown in these drawings may be shown with dimensions different from those of the actual structures in order to show the characteristic parts in an easy-to-understand manner. In the present embodiment, the present invention is applied to an active matrix liquid crystal display device using a TFT (Thin Film Transistor) element, which is a three-terminal switching element, as a switching element.

  The overall configuration of the liquid crystal display device according to this embodiment is substantially the same as that of the previous embodiment shown in FIGS. The difference is that in the previous embodiment, the TFD element 21 (see FIG. 3) was used as a switching element, but in this embodiment, a TFT element was used instead. Some changes have been made. The TFT elements, that is, switching elements are formed on the element substrate 11 of FIG. 2, and the color filters, that is, coloring elements are formed on the color filter substrate 12, as in the previous embodiment.

  6 is an enlarged cross-sectional view of the pixel portion indicated by the arrow C in FIG. FIG. 7 is a plan view showing an enlarged pixel portion from the direction of arrow A in FIG. In FIG. 6, a cell gap G is formed between the element substrate 11 and the color filter substrate 12, and the liquid crystal layer 10 is formed in the cell gap G.

  A coloring element 71 is formed on the second light-transmitting substrate 12a, which is a component of the color filter substrate 12, and a light shielding member 72 is formed so as to surround the coloring element 71. An overcoat layer 73 as a resin layer is formed thereon. The common electrode 64b is formed thereon, and the alignment film 66b is formed thereon. The common electrode 64b used in the present embodiment is provided in a plane with a uniform thickness on the second light transmitting substrate 12a.

  The TFT element used in this embodiment is an amorphous TFT element. This TFT element is a component of the element substrate 11 as shown by reference numeral 51 in FIG. 6 which is a cross-sectional view according to the line KK in FIG. A gate electrode 52 formed on a certain first transparent substrate 11a, a gate insulating film 53 formed on the substrate 11a so as to cover it, and formed on the gate electrode 52 through the gate insulating film 53 The semiconductor layer 54 made of amorphous silicon (a-Si), the source electrode 55 formed so as to be connected to one of the semiconductor layers 54, and the drain electrode 56 formed so as to be connected to the other of the semiconductor layers 54 And have.

  The source electrode 55 extends from a source electrode line 55 'serving as a wiring extending in a direction perpendicular to the paper surface of FIG. Further, the gate electrode 52 extends from a gate electrode line 52 ′ as a wiring extending in the left-right direction in FIG. 6 (left-right direction in FIG. 7). As shown in FIG. 7, the source electrode line 55 'and the gate electrode line 52' are formed so as to be orthogonal to each other through an insulating film. The source electrode line 55 'is electrically connected to one of the three driving ICs 39 in FIG. 1 and supplied with a data signal. Further, the gate electrode line 52 ′ in FIG. 7 is electrically connected to two on both sides of the three driving ICs 39 in FIG. 1 and supplied with a scanning signal.

  In the present embodiment in which the TFT element is used as the switching element, the data line and the scanning line are both formed on the element substrate 11, and therefore, the conductive material 37 dispersed in the sealing material 5 in FIG. 2 is used. A vertical conduction structure is not required.

  In FIG. 6, an interlayer insulating film 62 is provided on the TFT element 51 and the gate insulating film 53, a light reflecting film 63 is formed thereon, a pixel electrode 64a is formed thereon, and an alignment film 66a is formed thereon. Is formed. A region R where the light reflecting film 63 exists in the sub-pixel region D is a reflective display region, and a region T where the light reflecting film 63 does not exist is a transmissive display region. In the present embodiment, the reflective electrode is formed by two layers of the light reflective film 63 and the pixel electrode 64a.

  FIG. 8 is an enlarged view of a portion indicated by an arrow I in FIG. 6, that is, a portion where the TFT element 51 is formed. In FIG. 8, the overcoat layer 73 is formed on the color filter substrate 12 and on the coloring elements 71 and the light shielding member 72. The TFT element 51 is formed on the inner surface of the element substrate 11 facing the color filter substrate 12. In the planar region in which the pixel electrode 64a is provided, that is, in the sub-pixel region D, the overcoat layer 73 has a layer thickness t1 in the region V0 that planarly overlaps the TFT element 51 compared to the layer thickness t2 in the peripheral region. Thinly formed.

  In the present embodiment, the region V0 that planarly overlaps the TFT element 51 is a region that includes at least the width W0 of the TFT element 51 as viewed in the cross section shown in FIG. Specifically, the region includes from the end of the source electrode 55 to the end of the drain electrode 56. This region V0 is a curved region that encloses the entire TFT element 51 roughly along the outline of the TFT element 51 when viewed in plan as shown in an enlarged manner by an arrow J in FIG.

  In FIG. 8, the layer thickness t1 of the overcoat layer 73 in the region V0 is determined by the thickness t0 of the TFT element 51 from the surface of the first translucent substrate 11a. Specifically, the thickness t0 is formed thinner than the layer thickness t2 of the other overcoat layer 73 in the sub-pixel region D by the thickness t0 of the TFT element 51. The TFT element 51 is formed by stacking the gate electrode 52, the gate insulating film 53, the semiconductor layer 54, the source electrode 55, and the drain electrode 56 as described above, and the thickness thereof is shown in FIG. As can be seen, the entire TFT element 51 is not constant. Therefore, in the present embodiment, the thickness t0 of the TFT element 51 is set to the average thickness of the entire TFT element 51. Specifically, the thickness t3 of the thinnest portion (that is, the portion where the source electrode 55 and the drain electrode 56 are formed) and the thickest portion (that is, the gate electrode 52, the gate insulating film 53, the semiconductor layer 54, the source) This is the average thickness with the thickness t4 of the portion where the electrode 55 and the drain electrode 56 are laminated. FIG. 8 shows a case where the thickness t0 of the TFT element 51 serving as a reference for determining the layer thickness t1 of the overcoat layer 73 is the thickest thickness t4.

  According to this embodiment, even if the height h1 of the surface of the interlayer insulating film 62 is increased by the thickness t0 of the TFT element 51 in the region V0 where the TFT element 51 is provided, the layer thickness of the liquid crystal layer 10 is increased. That is, it is possible to prevent the cell gap G from becoming thin. That is, in the sub-pixel region D, the cell gap G0 in the region V0 and the cell gap G1 in other regions can be made uniform. As a result, it is possible to prevent display unevenness in the region V0 where the TFT element 51 is provided.

(Other embodiments of electro-optical device)
The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the invention described in the claims.
For example, in the first embodiment, as shown in FIG. 4, the region V <b> 0 that overlaps the TFD element 21 in a plane is a region that surrounds the entire TFD element 21 with a curve. However, this region V0 may be a region surrounding the entire TFD element 21 in a square shape as shown in FIG. Further, the region V0 may be a region surrounding a portion excluding the second element electrode 29b connected to the data line 14 as shown in FIG. 9B. Further, the region V0 may be a region that covers the thickest portion of the TFD element 21 as shown in FIG. Specifically, it is a portion indicated by W1 in FIG. 5, and more specifically, a portion where the first element electrode 27, the insulating film 28, and the second element electrodes 29a and 29b are laminated. In this case, it is desirable to set the thickness t0 of the TFD element 21, that is, the difference between the layer thicknesses t1 and t2 of the overcoat layer 33, to the thickness of the thickest portion of the TFD element 21.

  In the second embodiment, as shown in FIG. 7, the region V <b> 0 that overlaps the TFT element 51 in a plan view is the region that surrounds the entire TFT element 51 with a curve. However, this region V0 may be a region surrounding the entire TFT element 51 in a square shape as shown in FIG. Further, as shown in FIG. 10B, the region V0 is a region surrounding a portion excluding the gate electrode 52 connected to the gate electrode line 52 ′ and the source electrode 55 connected to the source electrode line 55 ′. Also good. Further, the region V0 may be a region covering the thickest part of the TFT element 51 as shown in FIG. Specifically, it is a portion indicated by W1 in FIG. 8, and more specifically, a portion where the gate electrode 52, the gate insulating film 53, the semiconductor layer 54, the source electrode 55, and the drain electrode 56 are stacked. In this case, the thickness t0 of the TFT element 51, that is, the difference between the layer thicknesses t1 and t2 of the overcoat layer 73 is preferably set to the thickness of the thickest portion of the TFT element 51.

  In the embodiment shown in FIG. 6, the present invention is applied to a liquid crystal display device using an amorphous TFT element as a switching element. However, the present invention can be applied to other switching elements such as a high-temperature polysilicon TFT element, a low-temperature poly-crystal element, and the like. It can also be applied to a liquid crystal display device using a silicon TFT element or the like.

  The present invention also provides an electro-optical device other than a liquid crystal display device, for example, an organic EL device, an inorganic EL device, a plasma display device (PDP), an electrophoretic display (EPD), a field emission display device ( It can also be applied to FED (Field Emission Display).

(Embodiment of electronic device)
Hereinafter, an electronic device according to the present invention will be described with reference to embodiments. In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment.

  FIG. 11 shows an embodiment of an electronic apparatus according to the invention. The electronic apparatus shown here includes a liquid crystal display device 101 and a control circuit 100 that controls the liquid crystal display device 101. The control circuit 100 includes a display information output source 104, a display information processing circuit 105, a power supply circuit 106, and a timing generator 107. The liquid crystal display device 101 includes a liquid crystal panel 102 and a drive circuit 103.

  The display information output source 104 includes a memory such as a random access memory (RAM), a storage unit such as various disks, a tuning circuit that tunes and outputs a digital image signal, and various clock signals generated by the timing generator 107. Based on the above, display information such as an image signal in a predetermined format is supplied to the display information processing circuit 105.

  Next, the display information processing circuit 105 includes a number of well-known circuits such as an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, a clamp circuit, and the like, executes processing of input display information, and outputs an image signal. It is supplied to the drive circuit 103 together with the clock signal CLK. Here, the drive circuit 103 is a generic term for an inspection circuit and the like together with a scanning line drive circuit and a data line drive circuit. The power supply circuit 106 supplies a predetermined power supply voltage to each of the above components.

  The liquid crystal display device 101 can be configured using, for example, a liquid crystal display device having the configuration shown in FIG. 5 or FIG. According to the liquid crystal display device shown in FIG. 5, the thickness of the liquid crystal layer 10 can be increased by forming the overcoat layer 33 in the region V <b> 0 that overlaps the TFD element 21 in a plan view thinner than the surrounding region. Since non-uniformity can be prevented, unevenness in display can be prevented. Further, according to the liquid crystal display device shown in FIG. 8, the layer of the liquid crystal layer 10 is formed by forming the thickness of the overcoat layer 73 in the region V <b> 0 that overlaps the TFT element 51 in a plane as compared with the peripheral region. Since it is possible to prevent the thickness from becoming uneven, it is possible to prevent unevenness in display. Accordingly, even in the electronic apparatus using the electro-optical device according to the present invention, it is possible to prevent the display performed using the liquid crystal display device 101 from being uneven.

  FIG. 12 shows a mobile phone which is another embodiment of the electronic apparatus according to the invention. A cellular phone 110 shown here includes a main body 111 and a display body 112 that can be opened and closed. A display device 113 configured by an electro-optical device such as a liquid crystal display device is disposed inside the display body portion 112, and various displays relating to telephone communication can be visually recognized on the display body portion 112 on the display screen 114. Operation buttons 115 are arranged on the main body 111.

  An antenna 116 is attached to one end of the display body 112 so as to be extendable and contractible. A speaker (not shown) is arranged inside the receiver unit 117 provided at the upper part of the display body unit 112. Further, a microphone (not shown) is built in the transmitter 118 provided at the lower end of the main body 111. A control unit for controlling the operation of the display device 113 is stored inside the main body unit 111 or the display body unit 112 as a part of the control unit that controls the entire mobile phone or separately from the control unit. The

  The display device 113 can be configured using, for example, a liquid crystal display device configured as shown in FIG. 5 or FIG. According to the liquid crystal display device shown in FIG. 5, the thickness of the liquid crystal layer 10 can be increased by forming the overcoat layer 33 in the region V <b> 0 that overlaps the TFD element 21 in a plan view thinner than the surrounding region. Since non-uniformity can be prevented, unevenness in display can be prevented. Further, according to the liquid crystal display device shown in FIG. 8, the layer of the liquid crystal layer 10 is formed by forming the thickness of the overcoat layer 73 in the region V <b> 0 that overlaps the TFT element 51 in a plane as compared with the peripheral region. Since it is possible to prevent the thickness from becoming uneven, it is possible to prevent unevenness in display. Accordingly, even in the electronic apparatus using the electro-optical device according to the invention, it is possible to prevent the display performed using the display device 113 from being uneven.

(Modification)
In addition to the above-described mobile phones and the like as electronic devices, personal computers, liquid crystal televisions, viewfinder type or monitor direct view type video tape recorders, car navigation devices, pagers, electronic notebooks, calculators, word processors, Examples include workstations, video phones, and POS terminals.

1 is a perspective view showing an embodiment of an electro-optical device according to the invention. It is sectional drawing according to the BB line of FIG. It is sectional drawing which expands and shows the part shown by the arrow C of FIG. It is a top view which shows a pixel part from the arrow A direction of FIG. It is sectional drawing which expands and shows the part shown by the arrow F of FIG. FIG. 10 is a cross-sectional view illustrating a main part of another embodiment of the electro-optical device according to the invention. It is a top view which shows a pixel part from the arrow A direction of FIG. It is sectional drawing which expands and shows the part shown by the arrow I of FIG. It is a figure which shows the modification of the part shown expanded by the arrow H of FIG. It is a figure which shows the modification of the part expanded and shown by the arrow J of FIG. It is a block diagram which shows one Embodiment of the electronic device which concerns on this invention. It is a perspective view which shows other embodiment of the electronic device which concerns on this invention.

Explanation of symbols

1. 1. liquid crystal display device (electro-optical device), LCD panel (electro-optical panel),
3. 3. lighting device; 4. FPC board, Seal material, 6. LED, 7. Light guide,
8). 8. light diffusion layer; A light reflection layer, 10. Liquid crystal layer (electro-optic material layer),
11. Element substrate, 11a. 11. a first translucent substrate; Color filter substrate,
12a. 2nd translucent board | substrate, 13a, 13b. Polarizing plate, 14. Data line,
21. TFD element (switching element), 21a. A first TFD element;
21b. Second TFD element, 22,62. Interlayer insulation film (insulation film),
23, 63. Light reflecting film,
24a, 64a. Pixel electrode, 24b. Band electrode, 25. Contact hole,
26a, 26b, 66a, 66b. Alignment film, 27. First element electrode, 28. Insulation film,
29a, 29b. Second element electrode 31, 71. Coloring elements, 32,72. Light shielding member,
33, 73. 35. overcoat layer (resin layer) 35. Overhang part. wiring,
36. Terminal for external connection, 39. Driving IC, 51. TFT element (switching element),
52. A gate electrode, 52 '. Gate electrode line, 53. Gate insulation film,
54. Semiconductor layer, 55. Source electrode, 55 '. Source electrode wire,
56. Drain electrode, 64b. Common electrode, 100. Control circuit,
101. Liquid crystal display device (electro-optical device), 102. LCD panel (electro-optical panel),
103. Drive circuit, 110. Mobile phones (electronic devices),
113. Display device (electro-optical device); A sub-pixel region; Reflective display area,
T.A. Transparent display area

Claims (8)

A substrate,
A switching element provided on the substrate;
An insulating layer formed on the switching element;
A reflective electrode formed on the insulating layer and connected to the switching element through a contact hole provided in the insulating layer;
A counter substrate provided facing the substrate;
A resin layer provided on a surface of the counter substrate facing the substrate;
The electro-optical device is characterized in that a thickness of the resin layer in a region overlapping the switching element in a plan view is smaller than a thickness of a peripheral region.   The electro-optical device according to claim 1, wherein the reflective electrode is formed of a single layer of a light-reflective and conductive material, or a stacked layer of a light-reflective film and a pixel electrode. An electro-optical device.   3. The electro-optical device according to claim 1, further comprising a coloring element on the counter substrate on the side facing the substrate, wherein the resin layer is an overcoat layer that covers the coloring element. An electro-optical device.   4. The electro-optical device according to claim 1, wherein the region in which the resin layer is formed to be thin is a region that covers the entire switching element in a planar manner. Electro-optical device characterized.   4. The electro-optical device according to claim 1, wherein the region where the thickness of the resin layer is formed covers at least the highest portion of the switching element in a planar manner. An electro-optical device that is a region.   6. The electro-optical device according to claim 1, wherein the switching element is a TFD element formed by sandwiching an insulating film between a pair of electrodes.   6. The electro-optical device according to claim 1, wherein the switching element is a TFT element having a semiconductor layer sandwiched between a plurality of electrodes. An electronic apparatus comprising the electro-optical device according to claim 1.

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