JP2006227156A - Liquid crystal display device and electronic appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device, in which electric resistance is lowered while retaining continuity between substrates. <P>SOLUTION: A conductive protrusion 72 is formed on a color filter substrate 10 out of a pair of substrates 10, 25 with a liquid crystal layer 50 interposed in between, for the purpose of retaining continuity with the element substrate 25. An end face of the conductive protrusion 72 is made to be a projecting and recessing face having a plurality of protrusions 72a. Besides, relative positions of the pair of substrates 10, 25 are fixed in the state in which the end face of the conductive protrusion 72 is brought into contact with the element substrate 25 and the protrusions 72a are compressed and deformed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device and an electronic apparatus.

  Liquid crystal display devices are widely used as image display means for electronic devices such as mobile phones. A liquid crystal display device is configured by sandwiching a liquid crystal layer between a pair of substrates on which electrodes are formed, applies an electric field between the electrodes to align liquid crystal molecules, and controls the light transmittance of the liquid crystal layer in units of pixels. Thus, an image is displayed.

FIG. 11 is a side sectional view of a liquid crystal display device according to the prior art described in Patent Document 1. In this liquid crystal display device, the element substrate 25 and the color filter substrate (CF substrate) 10 are bonded together with a sealant 19 interposed therebetween. The routing wiring 78 formed on the element substrate 25 and the scanning line 9 formed on the CF substrate 10 are electrically connected via the conductive particles 80 dispersed in the sealing material 19.
JP 2003-5196 A

  However, in the liquid crystal display device described above, the concentration of the conductive particles 80 dispersed in the sealing material 19 becomes a problem. If the concentration of the conductive particles 80 is too high, the adhesive force between the substrates by the sealing material 19 becomes weak. If the concentration of the conductive particles 80 is too low, the conductive particles are not arranged between some of the wirings, and conduction is ensured. This is because there is a risk that it will not be possible. In addition, even if the diameter of the conductive particles 80 varies, there is a possibility that conduction cannot be secured between some of the wirings.

  Furthermore, since the wirings of both substrates and the conductive particles 80 are in point contact, there is a problem that the electrical resistance of the conducting portion is increased. A structure in which the electrical resistance is lowered by compressing and deforming the conductive particles 80 and bringing them into surface contact with both substrates is also conceivable. However, a large load is required to compress and deform the conductive particles 80.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a liquid crystal display device that can reduce electrical resistance while ensuring conduction between substrates.
It is another object of the present invention to provide an electronic device with excellent electrical connection reliability.

In order to achieve the above object, in the liquid crystal display device of the present invention, at least the first substrate out of the pair of substrates sandwiching the liquid crystal layer ensures conduction with the second substrate out of the pair of substrates. Conductive protrusions are formed, the tip surfaces of the conductive protrusions are brought into contact with the second substrate, and the conductive protrusions are compressed and deformed, and the first substrate and the second substrate are A liquid crystal display device in which a relative position is fixed, wherein a tip surface of the conductive protrusion is an uneven surface.
According to this configuration, the conductive protrusion brought into contact with the second substrate can be easily compressed and deformed. Therefore, even when the conductive protrusions are formed slightly lower due to manufacturing errors or the like, conduction between the substrates can be ensured. Moreover, it becomes possible to increase the contact area of an electroconductive protrusion and a 2nd board | substrate, and can reduce the electrical resistance in the conduction | electrical_connection part between board | substrates.

In addition, it is desirable that the conductive protrusion is formed by disposing a conductive film on the surface of a core member made of an elastic material, and the tip surface of the core member is an uneven surface.
According to this structure, it becomes possible to hold | maintain the electroconductive protrusion in the state urged | biased toward the 2nd board | substrate, and can ensure the conduction | electrical_connection between board | substrates.

In addition, the front end surface of the conductive protrusion is an uneven surface having a plurality of protrusions, and the first protrusion is in a state where the protrusion is brought into contact with the second substrate and the protrusion is compressed and deformed. It is desirable that the relative position between the substrate and the second substrate is fixed.
According to this configuration, even when the height of the conductive protrusion is formed slightly higher due to a manufacturing error or the like, the conductive protrusion can be easily compressed and deformed with a small force, thereby realizing a desired cell gap. Can

On the other hand, an electronic apparatus according to the present invention includes the above-described liquid crystal display device.
According to this configuration, since the liquid crystal display device in which conduction between the substrates is ensured is provided, an electronic apparatus having excellent electrical connection reliability can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size. In the present specification, the liquid crystal layer side in each component of the liquid crystal display device is referred to as an inner side, and the opposite side is referred to as an outer side.

[First Embodiment]
First, a liquid crystal display device according to a first embodiment of the present invention will be described with reference to FIGS. The liquid crystal display device according to the first embodiment shown in FIG. 4 is a transmissive liquid crystal display device, in which a liquid crystal layer 50 is sandwiched between an element substrate 25 and a color filter substrate (CF substrate) 10. A pixel electrode 31 for applying a voltage to the liquid crystal layer 50 is formed between the substrate 25 and the liquid crystal layer 50. The liquid crystal layer 50 has a dielectric anisotropy that is aligned substantially perpendicular to the electric field direction when a selection voltage is applied. Is composed of negative liquid crystal molecules. In the first embodiment, an active matrix liquid crystal display device including a thin film diode (TFD) element will be described as an example. However, the present invention may be applied to a passive matrix liquid crystal display device. Is possible.

(Liquid crystal display device)
FIG. 1 is an exploded perspective view of a liquid crystal display device. The liquid crystal display device 100 is configured by bonding the CF substrate 10 so that the end of the element substrate 25 is exposed. The data line 11 formed on the element substrate 25 is routed to the exposed end portion of the element substrate 25. The scanning line 9 formed on the CF substrate 10 is also routed to the end portion of the element substrate 25 through the inter-substrate conduction portion 70 and the routing wiring 78.

  The driving IC 4 is mounted on the end of the element substrate 25 and is electrically connected to the data line 11 and the scanning line 9. The driving IC 4 is also electrically connected to a flexible printed circuit board (FPC) 5 mounted on the end of the element substrate 25. Then, a signal is supplied from the outside to the driving IC 4 via the FPC 5, and further, a signal is supplied from the driving IC 4 to the pixel area of the liquid crystal display device 100 via the data line 11 and the scanning line 9. As a result, the liquid crystal display device 100 is driven to display an image.

(Equivalent circuit)
FIG. 2 is an equivalent circuit diagram of a liquid crystal display device using a TFD element. In the image display area of the liquid crystal display device 100, a plurality of scanning lines 9 driven by the scanning signal driving circuit 110 and a plurality of data lines 11 driven by the data signal driving circuit 120 are arranged in a grid pattern. Yes. TFD elements 13 and liquid crystal display elements (liquid crystal layers) 50 are arranged near the intersections of the scanning lines 9 and the data lines 11, respectively. Each TFD element 13 and each liquid crystal layer 50 are connected in series between each scanning line 9 and each data line 11.

(Planar structure)
FIG. 3 is a partial perspective view showing a display area of a liquid crystal display device using a TFD element. The liquid crystal display device 100 of this embodiment is mainly composed of an element substrate 25 and a CF substrate 10 facing each other, and a liquid crystal layer (not shown) is sandwiched between the substrates 10 and 25.

The element substrate 25 includes a substrate body 25A made of a translucent material such as glass, plastic, or quartz. A plurality of data lines 11 are provided in a stripe shape on the inner side (lower side in the figure) of the substrate body 25A. Further, a plurality of pixel electrodes 31 having a substantially rectangular shape in plan view made of a transparent conductive material such as ITO (indium tin oxide) are arranged in a matrix.
Each pixel electrode 31 is connected to the data line 11 via the TFD element 13.
The TFD element 13 includes a first conductive film mainly composed of Ta formed on the substrate surface, an insulating film mainly composed of Ta ₂ O ₃ formed on the surface of the first conductive film, and an insulating film formed by the insulating film. A second conductive film mainly composed of Cr formed on the surface of the film (so-called MIM structure). The first conductive film is connected to the data line 11 and the second conductive film is connected to the pixel electrode 31. Accordingly, the TFD element 13 functions as a switching element that controls energization to the pixel electrode 31.

  On the other hand, the CF substrate 10 includes a substrate body 10A made of a translucent material such as glass, plastic, or quartz. Further, a color filter layer (CF layer) 22 and a plurality of counter electrodes (scanning lines) 9 are formed on the inner side (upper side in the drawing) of the substrate body 10A. The CF layer 22 has a configuration in which color filters 22R, 22G, and 22B having a substantially rectangular shape in plan view are periodically arranged. Each of the color filters 22R, 22G, and 22B is formed corresponding to the pixel electrode 31 of the element substrate 25. A counter electrode 9 is formed so as to cover the color filters 22R, 22G, and 22B. The counter electrode 9 is formed in a substantially strip shape by a transparent conductive material such as ITO, and extends in a direction intersecting with the data line 11 of the element substrate 25 and functions as a scanning line. One dot is constituted by the formation region of the pixel electrode 31, and one pixel is constituted by 3 dots provided with the color filters 22R, 22G, and 22B.

(Cross-section structure)
4 is a side cross-sectional view taken along line AA in FIG. In FIG. 4, the description of the TFD elements and various wirings in the element substrate 25 is omitted for easy understanding.

  The element substrate 25 and the CF substrate 10 are bonded to each other by a sealing material (not shown) applied to the peripheral edge thereof. A liquid crystal layer 50 is sealed in a space formed by the element substrate 25 and the CF substrate 10 and the sealing material. The thickness (cell gap) of the liquid crystal layer 50 is regulated by bringing a photo spacer 52 erected on the CF substrate 10 into contact with the element substrate 25. The photo spacer 52 is made of acrylic resin or the like, and is arranged at the peripheral edge of the pixel region. A black matrix 28 is formed by laminating color filters 22R, 22G, and 22B at the peripheral edge of the pixel region. By forming the photo spacer 52 over the black matrix 28 via the overcoat layer 29, the aspect ratio of the photo spacer 52 is reduced.

  On the inner surfaces of the element substrate 25 and the CF substrate 10, alignment films 33 and 23 for aligning liquid crystal molecules when a non-selection voltage is applied are formed. The liquid crystal layer 50 sandwiched between the element substrate 25 and the CF substrate 10 is made of a liquid crystal material having negative dielectric anisotropy. As conceptually shown by the liquid crystal molecules 51, this liquid crystal material is aligned substantially perpendicular to the alignment film when a non-selection voltage is applied, and is substantially parallel to the alignment films 33 and 23 when a selection voltage is applied (ie, (Or substantially perpendicular to the electric field direction). Here, “when non-selective voltage is applied” and “when selective voltage is applied” are respectively “when the applied voltage to the liquid crystal layer is close to the threshold voltage of the liquid crystal” and “applied voltage to the liquid crystal layer is It means “when it is sufficiently higher than the threshold voltage”.

  In addition, it is desirable to provide alignment regulating means (not shown) such as dielectric protrusions and electrode slits on the element substrate 25 and the liquid crystal layer 50 side of the CF substrate 10. The alignment regulating means is configured to incline and align the liquid crystal molecules in a certain direction from the vertical direction of the substrates 10 and 25 when a non-selection voltage is applied. By providing such alignment regulating means, a plurality of directors of liquid crystal molecules can be created, and a liquid crystal display device having a wide viewing angle can be provided.

  On the other hand, a phase difference plate 36 and a polarizing plate 37 are provided on the outer surface of the element substrate 25, and a phase difference plate 26 and a polarizing plate 27 are also provided on the outer surface of the CF substrate 10. The polarizing plates 27 and 37 have a function of transmitting only linearly polarized light that vibrates in a specific direction. The retardation plates 26 and 36 are λ / 4 plates having a phase difference of approximately ¼ wavelength with respect to the wavelength of visible light. The transmission axes of the polarizing plates 27 and 37 and the slow axis of the retardation plates 26 and 36 are arranged at about 45 °, and the polarizing plates 27 and 37 and the retardation plates 26 and 36 are respectively circularly polarized. A plate is constructed. With this circularly polarizing plate, linearly polarized light can be converted into circularly polarized light, and circularly polarized light can be converted into linearly polarized light. Further, the transmission axis of the polarizing plate 27 and the transmission axis of the polarizing plate 37 are arranged to be orthogonal to each other, and the slow axis of the retardation film 26 and the slow axis of the retardation film 36 are also arranged to be orthogonal.

Further, a backlight (illuminating means) 60 having a light source, a reflector, a light guide plate, and the like is installed outside the liquid crystal cell corresponding to the outer surface side of the CF substrate 10.
In the transmissive liquid crystal display device shown in FIG. 4, image display is performed as follows. Light that has entered the CF substrate 10 from the backlight 60 passes through the polarizing plate 27 and the retardation plate 26, is converted into circularly polarized light, and enters the liquid crystal layer 50. When the non-selection voltage is applied, the vertically aligned liquid crystal molecules have no refractive index anisotropy, so that incident light passes through the liquid crystal layer 50 while maintaining circular polarization. Further, the circularly polarized light is converted into linearly polarized light orthogonal to the transmission axis of the polarizing plate 37 in the process of passing through the phase difference plate 36. Since this linearly polarized light does not pass through the polarizing plate 37, the liquid crystal display device of this embodiment performs black display when a non-selection voltage is applied (normally black mode).

  Further, when a selection voltage is applied to the liquid crystal layer 50, the liquid crystal molecules are realigned substantially parallel to the substrate (substantially perpendicular to the electric field direction) to have refractive index anisotropy. Therefore, the circularly polarized light incident on the liquid crystal layer 50 is converted into elliptically polarized light in the process of passing through the liquid crystal layer 50. Even if this incident light passes through the phase difference plate 36, it is not converted into linearly polarized light orthogonal to the transmission axis of the polarizing plate 37, and all or part of it is transmitted through the polarizing plate 37. Therefore, in the liquid crystal display device of the present embodiment, white display is performed when the selection voltage is applied. Note that gradation display can be performed by adjusting the voltage applied to the liquid crystal layer 50.

(Conductor between boards)
FIG. 5A is a side sectional view of an end portion of the liquid crystal display device according to the second embodiment. As described above, the element substrate 25 and the CF substrate 10 are bonded to each other by the sealing material 19 applied to the peripheral portions thereof. A liquid crystal layer 50 is sealed in a space formed by the element substrate 25 and the CF substrate 10 and the sealing material 19. The scanning lines 9 formed on the CF substrate 10 are routed to the element substrate 25 via the inter-substrate conductive portion 70 and the routing wiring 78 (see also FIG. 1). A plurality of inter-substrate conductive portions 70 and routing wirings 78 are formed corresponding to the plurality of scanning lines 9 formed on the CF substrate 10.

  The inter-substrate conduction portion 70 shown in FIG. 5A is obtained by bringing a conductive protrusion 72 formed on the CF substrate 10 and a lead wiring 78 formed on the element substrate 25 into contact with each other. . The conductive protrusion 72 includes a core member 74 formed on the inner surface of the CF substrate 10 and made of an elastic material or the like, and a conductive film 76 formed on the surface of the core member 74 and made of ITO or the like. The conductive film 76 is electrically connected to the scanning line 9 formed on the CF substrate 10. If a photosensitive resin is employed as the elastic material constituting the core member 74, the core member 74 can be easily formed by a photolithography technique.

  On the other hand, the routing wiring 78 of the element substrate 25 extends to the end of the element substrate 25 along the outside of the sealing material 19. A pad that is electrically connected to the routing wiring 78 may be formed at a position where the inter-substrate conductive portion 70 is formed. The relative position between the CF substrate 10 and the element substrate 25 is fixed in a state where the tip of the conductive protrusion 72 is in contact with the surface of the routing wiring 78. Thereby, the conduction | electrical_connection between board | substrates is ensured.

  FIG.5 (b) is an enlarged view of the C section of Fig.5 (a). FIG. 5B shows a state in which the wiring 78 is simply brought around the tip of the conductive protrusion 72 and brought into contact therewith. The tip surface of the conductive protrusion 72 described above is an uneven surface. Specifically, the tip surface of the core member 74 is an uneven surface, and a uniform conductive film 76 is formed on the surface, so that the tip surface of the conductive protrusion 72 is an uneven surface having a height of about 0.5 μm. Yes. The leading end surface of the core member may be a flat surface, and an uneven conductive film may be formed on the surface.

  In order to make the tip surface of the core member 74 an uneven surface, a photolithography method, a shape transfer (stamper) method, a polishing method, a blast method, an ashing method, or the like can be used. In the photolithography method, the resin material used as the core member 74 is exposed and developed using a photomask in which light and shade are formed in a region corresponding to the tip surface of the core member 74, whereby the tip surface of the core member 74 is uneven. A surface. In the shape transfer method, the front end surface of the core member 74 is pressed by pressing the front end surface of the core member 74 using a transfer mold in which a reverse-shaped uneven surface is formed in a region corresponding to the front end surface of the core member 74. The surface is uneven. In the polishing method, the height of the core member 74 is formed slightly higher in advance, and the tip end surface of the core member 74 is roughened by polishing the tip with a grinder or the like. In the blast method, the height of the core member 74 is formed slightly higher in advance, and the tip surface of the core member 74 is roughened by colliding fine particles with the tip portion. In the ashing method, the tip surface of the core member 74 is roughened by treating the tip surface of the core member 74 with oxygen plasma or the like.

  As shown in FIG. 5B, the height H of the conductive protrusion 72 before contacting the CF substrate 10 realizes a desired liquid crystal layer thickness (cell gap) by contacting the CF substrate 10. In this state, the conductive protrusion 72 is formed larger than the height G. The relative position between the CF substrate 10 and the element substrate 25 is fixed in a state where the element substrate 25 is pressed against the distal end surface of the conductive protrusion 72 and the conductive protrusion 72 is compressed and deformed. In addition, since the front end surface of the conductive protrusion 72 is an uneven surface, the conductive protrusion 72 can be easily compressed and deformed. Thereby, even when the height of the conductive protrusion 72 is formed slightly lower due to a manufacturing error or the like, it is possible to ensure conduction between the substrates. In particular, since the core member 74 is made of an elastic material, the conductive protrusion 72 can be held in a state of being biased to the element substrate 25, and conduction between the substrates can be ensured. In addition, by compressively deforming the conductive protrusions 72, the contact area with the routing wiring 78 can be increased, and the electrical resistance in the inter-substrate conducting portion can be reduced.

By the way, when the height of the conductive protrusion 72 is formed slightly high due to a manufacturing error or the like, a large force is required to compressively deform the conductive protrusion 72, and a desired liquid crystal layer thickness (cell gap) is required. ) May be difficult to achieve.
However, since the plurality of convex portions 72a are formed on the tip surface of the conductive protrusion 72 of this embodiment, the conductive protrusion 72 is formed in a mountain shape (that is, only one convex portion is formed). Compared to the case, the conductive protrusion 72 can be easily compressed and deformed with a small force. Therefore, even when the conductive protrusion 72 is formed slightly higher, a desired cell gap can be realized.

  As described in detail above, the liquid crystal display device according to the present embodiment has a configuration in which the front end surface of the conductive protrusion that ensures conduction between the CF substrate and the element substrate is an uneven surface. According to this configuration, the conductive protrusion in contact with the mating substrate can be easily compressed and deformed. Therefore, even when the conductive protrusions are formed slightly lower due to manufacturing errors or the like, conduction between the substrates can be ensured. In addition, it is possible to increase the contact area between the conductive protrusion and the routing wiring, and it is possible to reduce the electrical resistance in the inter-substrate conductive portion.

  In the first embodiment, the conductive protrusion formed on the CF substrate is brought into contact with the lead wiring formed on the element substrate. However, the conductive protrusion formed on the element substrate is brought into contact with the electrode pad formed on the CF substrate. You may let them. In this case, the conductive film of the conductive protrusion of the element substrate is routed to be conducted to the wiring, and the electrode pad of the CF substrate is conducted to the scanning line. On the other hand, conductive protrusions may be formed on both the CF substrate and the element substrate, and conduction between the substrates may be ensured by abutting them.

[Second Embodiment]
Next, a liquid crystal display device according to a second embodiment of the present invention will be described with reference to FIGS. The liquid crystal display device of the second embodiment shown in FIG. 8 is a transflective liquid crystal display device, in which a transmissive display region T and a reflective display region R are provided in the formation region (dot region) of the pixel electrode 31; This is different from the first embodiment, which is a transmissive liquid crystal display device, in that a liquid crystal layer thickness adjusting layer 21 is provided at least in the reflective display region R. Further, as shown in FIG. 7, the thin film transistor (TFT) element 30 is adopted as a switching element, which is different from the first embodiment adopting a TFD element. Note that detailed descriptions of portions having the same configurations as those of the first embodiment and the second embodiment are omitted.

(Liquid crystal display device)
FIG. 6 is a plan view of the element substrate of the liquid crystal display device according to the second embodiment. An image display area 101 is formed at the center of the element substrate 25, and a sealing material 19 is disposed on the periphery thereof. On the outside of the sealing material 19, a driving IC constituting the scanning signal driving circuit 110 and the data signal driving circuit 120 is mounted. Further, wiring is routed from the drive circuits 110 and 120 to the connection terminal 8 at the end of the element substrate 25.

On the other hand, a common electrode 7 is formed on a CF substrate (not shown) bonded to the element substrate 25. The common electrode 7 is formed over almost the entire area of the image display area 101, and an inter-substrate conducting part 70 is provided at at least one of the peripheral edges. In FIG. 6, inter-substrate conducting portions 70 are provided at the four corners of the common electrode 7. Further, a lead wiring 78 is formed from the inter-substrate conducting portion 70 to the connection terminal 8.
Then, an externally input signal is supplied to the image display area 101 via the connection terminal 8. Thereby, the liquid crystal display device is driven to display an image.

(Equivalent circuit)
FIG. 7 is an equivalent circuit diagram of a liquid crystal display device using TFT elements. In the image display area of the liquid crystal display device, the data lines 6a and the gate lines 3a are arranged in a lattice pattern, and dots as image display units are arranged in the vicinity of their intersections. A plurality of dots arranged in a matrix form a pixel electrode 31 and a TFT element 30 that is a switching element for controlling energization of the pixel electrode 31. A data line 6 a is electrically connected to the source of the TFT element 30. Image signals S1, S2,..., Sn are supplied to each data line 6a. The image signals S1, S2,..., Sn may be supplied to each data line 6a in this order, or may be supplied for each group to a plurality of adjacent data lines 6a.

  A gate line (scanning line) 3 a is electrically connected to the gate of the TFT element 30. The gate lines 3a are supplied with scanning signals G1, G2,..., Gn in a pulsed manner at a predetermined timing. The scanning signals G1, G2,..., Gn are applied sequentially to the respective gate lines 3a in this order. A pixel electrode 31 is electrically connected to the drain of the TFT element 30. When the TFT elements 30 serving as switching elements are turned on for a certain period by the scanning signals G1, G2,..., Gn supplied from the gate line 3a, the image signals S1, S2,. , Sn are written to the liquid crystal of each pixel at a predetermined timing.

  Image signals S1, S2,..., Sn written at a predetermined level in the liquid crystal are held for a certain period by a liquid crystal capacitor formed between the pixel electrode 31 and the common electrode. In order to prevent leakage of the held image signals S1, S2,..., Sn, a storage capacitor 17 is formed between the pixel electrode 31 and the capacitor line 3b, and is arranged in parallel with the liquid crystal capacitor. . When a voltage signal is applied to the liquid crystal as described above, the alignment state of the liquid crystal molecules changes according to the applied voltage level. As a result, light incident on the liquid crystal is modulated to enable gradation display.

(Cross-section structure)
FIG. 8 is a side sectional view of the liquid crystal display device according to the second embodiment. In FIG. 8, the description of the TFT elements and the various wirings in the element substrate 25 is omitted for easy understanding. As described above, when a TFT element is employed, it is necessary to form a storage capacitor between the pixel electrode 31 and the capacitor line. Therefore, if the pixel electrode 31 is disposed on the light source side substrate and the capacitor line is disposed outside the pixel electrode 31, it is possible to avoid a decrease in the aperture ratio due to the capacitor line. Therefore, in the present embodiment, a case where the element substrate 25 is disposed on the light source side (lower side) and the CF substrate 10 is disposed on the observer side (upper side) will be described as an example.

  At one end of the dot region inside the element substrate 25, a resin layer 20a having an uneven surface is formed. On the surface of the resin layer 20a, a reflective film 20 made of a highly reflective metal film such as aluminum or silver is formed. An overlapping portion between the formation region of the reflective film 20 and the formation region of the pixel electrode 31 is a reflective display region R, and an overlap portion between the non-formation region of the reflective film 20 and the formation region of the pixel electrode 31 is a transmissive display region T. It has become.

  A liquid crystal layer thickness adjusting layer 21 is formed on the surface of the reflective film 20. The liquid crystal layer thickness adjusting layer 21 is made of an electrically insulating material such as an acrylic resin, and has a thickness of, for example, about 0.5 to 2.5 μm. Thereby, the layer thickness of the liquid crystal layer 50 in the reflective display region R is set to about half of the layer thickness of the liquid crystal layer 50 in the transmissive display region T, thereby realizing a multi-gap structure.

  In the transflective liquid crystal display device, incident light to the reflective display region R passes through the liquid crystal layer 50 twice, but incident light to the transmissive display region T passes through the liquid crystal layer 50 only once. In this case, if the retardation (phase difference value) of the liquid crystal layer 50 is different between the reflective display region R and the transmissive display region T, a difference occurs in the light transmittance and a uniform image display cannot be obtained. However, by providing the liquid crystal layer thickness adjusting layer 21, the retardation can be adjusted in the reflective display region R. Accordingly, uniform image display can be obtained in the reflective display region R and the transmissive display region T.

The pixel electrode 31 in the reflective display region R is disposed on the inner surface of the liquid crystal layer thickness adjusting layer 21. An alignment film 33 is formed on the inner surface of the pixel electrode 31. On the other hand, an alignment film 23 is also formed on the inner surface of the common electrode 7.
Also in the second embodiment, in order to regulate the thickness (cell gap) of the liquid crystal layer 50, the photo spacer 52 is provided upright at the peripheral portion of the pixel region in the CF substrate. However, in the second embodiment, the liquid crystal layer thickness adjusting layer 21 is extended to the periphery of the pixel region in the element substrate 25, and the photo spacer 52 is brought into contact with the surface thereof. Thereby, the aspect ratio of the photo spacer 52 is reduced.

(Conductor between boards)
FIG. 9 is a side sectional view of an end portion of the liquid crystal display device according to the second embodiment. The common electrode 7 formed on the CF substrate 10 is routed to the element substrate 25 via the inter-substrate conduction portion 70 and the routing wiring 78 (see also FIG. 1). The inter-substrate conducting portion 70 shown in FIG. 9 is obtained by bringing a conductive protrusion 72 formed on the CF substrate 10 and a routing wiring 78 formed on the element substrate 25 into contact with each other. The conductive protrusion 72 includes a core member 74 formed on the inner surface of the CF substrate 10 and made of a resin material or the like, and a conductive film 76 formed on the surface of the core member 74 and made of ITO or the like. The conductive film 76 is electrically connected to the common electrode 7 formed on the CF substrate 10.

  The relative position between the CF substrate 10 and the element substrate 25 is fixed in a state in which the tip of the conductive protrusion 72 is in contact with the surface of the routing wiring 78. Thereby, the conduction | electrical_connection between board | substrates is ensured.

  Also in the second embodiment, the front end surface of the conductive protrusion 72 is an uneven surface formed with a plurality of convex portions. Specifically, the leading end surface of the core member 74 is an uneven surface, and a uniform conductive film 76 is formed on the surface. According to this configuration, the conductive protrusion in contact with the mating substrate can be easily compressed and deformed. Therefore, even when the conductive protrusions 72 are formed slightly lower due to manufacturing errors or the like, it is possible to ensure conduction between the substrates. In addition, the contact area between the conductive protrusion 72 and the routing wiring 78 can be increased, and the electrical resistance in the inter-substrate conducting portion can be reduced. Furthermore, since the conductive protrusion 72 can be easily compressed and deformed with a small force, a desired cell gap can be realized even when the conductive protrusion 72 is formed slightly higher due to a manufacturing error or the like.

  In the second embodiment, the conductive protrusion is formed on the CF substrate side of the inter-substrate conductive portion. However, it may be formed on the element substrate side or on both substrates. In the second embodiment, the thickness adjustment layer is formed on the element substrate side of the inter-substrate conduction portion, but it may be formed on the CF substrate side or on both substrates.

[Electronics]
FIG. 10 is a perspective view showing an example of an electronic apparatus according to the invention. A cellular phone 1300 illustrated in FIG. 10 includes the display device of the present invention as a small-sized display portion 1301 and includes a plurality of operation buttons 1302, a mouthpiece 1303, and a mouthpiece 1304.
The display device of each of the above embodiments is not limited to the mobile phone, but is an electronic book, a personal computer, a digital still camera, a liquid crystal television, a viewfinder type or a monitor direct view type video tape recorder, a car navigation device, a pager, and an electronic notebook. It can be suitably used as an image display means for a calculator, a word processor, a workstation, a video phone, a POS terminal, a device equipped with a touch panel, etc., and any electronic device is excellent in reliability of electrical connection.

  The technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications made to the above-described embodiments without departing from the spirit of the present invention. That is, the specific materials and configurations described in the embodiments are merely examples, and can be changed as appropriate.

1 is an exploded perspective view of a liquid crystal display device according to a first embodiment. 1 is an equivalent circuit diagram of a liquid crystal display device according to a first embodiment. It is a fragmentary perspective view in the display area of the liquid crystal display device concerning a 1st embodiment. It is side surface sectional drawing in the display area of the liquid crystal display device which concerns on 1st Embodiment. It is side surface sectional drawing in the edge part of the liquid crystal display device which concerns on 1st Embodiment. It is a top view of the liquid crystal display device which concerns on 2nd Embodiment. It is an equivalent circuit diagram of the liquid crystal display device according to the second embodiment. It is side surface sectional drawing in the display area of the liquid crystal display device which concerns on 2nd Embodiment. It is side surface sectional drawing in the edge part of the liquid crystal display device which concerns on 2nd Embodiment. It is a perspective view of a mobile phone. It is side surface sectional drawing in the edge part of the liquid crystal display device which concerns on a prior art.

Explanation of symbols

  10. Color filter substrate 25 Element substrate 50 Liquid crystal layer 72 Conductive protrusion 72a Projection

Claims (4)

Of the pair of substrates sandwiching the liquid crystal layer, at least the first substrate is provided with a conductive protrusion for ensuring electrical connection with the second substrate of the pair of substrates,
A liquid crystal display device in which a relative position between the first substrate and the second substrate is fixed in a state in which a tip surface of the conductive projection is brought into contact with the second substrate and the conductive projection is compressed and deformed. Because
A liquid crystal display device, wherein a tip end surface of the conductive protrusion is an uneven surface. The conductive protrusion is formed by disposing a conductive film on the surface of a core member made of an elastic material,
The liquid crystal display device according to claim 1, wherein a leading end surface of the core member is an uneven surface. The front end surface of the conductive protrusion is an uneven surface having a plurality of protrusions,
2. The relative position between the first substrate and the second substrate is fixed in a state where the convex portion is brought into contact with the second substrate and the convex portion is compressed and deformed. The liquid crystal display device according to claim 2.   An electronic apparatus comprising the liquid crystal display device according to any one of claims 1 to 3.

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