JP2006220786A - Active matrix type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of performing display in a frame area without newly preparing another dedicated display area. <P>SOLUTION: This display device is structured to hold a liquid crystal layer 42 between a TFT substrate 40 and CF substrate 41, and in an area A showing a part of a pixel forming part composing a main display part, a predetermined voltage is applied across a transparent conductive film 70 in a transmission display area a2 as well as a reflecting conductive film 72 in reflection display area a1 and a transparent conductive film 71 to vary an optical transmittance of the liquid crystal layer 42, and thereby reflection display and transmission display are performed, and also in an area B which is the frame area, the predetermined voltage is applied by a segment system across a shading resin layer 66 having a plurality of aperture parts of shapes to be displayed as well as a plurality of reflecting electrodes, which are the reflecting conductive film 72, and the above transparent conductive film 71. Thus, the reflection display is performed in the frame area. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an active matrix display device, and more specifically, a display region including a plurality of pixel formation portions arranged in a matrix in such a display device, and a position around the display region. The present invention relates to a display device having a frame region to be displayed.

  In general, an active matrix liquid crystal display device includes a display unit including two substrates sandwiching a liquid crystal layer, and one of the two substrates has a plurality of data as video signal lines. Lines and a plurality of gate lines as scanning signal lines are arranged in a lattice pattern, and a plurality of pixel formation portions are provided that are arranged in a matrix corresponding to the intersections of the plurality of data lines and the gate lines. Yes. Each pixel formation portion constitutes a display portion (display region) of the device, and a TFT (Thin Film Transistor) which is a switching element in which a gate terminal is connected to a gate line and a source terminal is connected to a data line. And a pixel electrode connected to the drain terminal of the TFT. The substrate including these pixel formation portions is called a TFT substrate.

  In addition, the other substrate facing the TFT substrate out of the two substrates displays a common color which is a common electrode provided in common to the plurality of pixel forming portions and a desired color by additive color mixing. And a color filter (CF: Color Filter) for forming at least two or more predetermined colors. This substrate is called a CF substrate.

  Such an active matrix type liquid crystal display device includes a data driver for driving the data line of the display unit, a gate driver for driving the gate line of the display unit, and a display control circuit for controlling the data driver and the gate driver. Various circuit groups other than the circuit of the display portion including these are called peripheral circuits. In recent years, a so-called driver (full) monolithic display device in which all of the peripheral circuits and a plurality of pixel circuits constituting the plurality of pixel forming portions are formed on a single TFT substrate, or a peripheral circuit is provided. The number of partial driver monolithic display devices including a part is increasing.

  Here, generally, peripheral circuits or various wirings are arranged in a so-called frame region that is a region around the display unit, and display is not performed in this frame region. This frame region is used as a region for applying a sealing agent for bonding the TFT substrate to the CF substrate at the time of manufacture even when the peripheral circuit and various wirings are not arranged. Often used as a region for separating each TFT substrate from a substrate including Therefore, this frame area is required regardless of whether peripheral circuits and various wirings are arranged.

In addition, some active matrix liquid crystal display devices have a sub display unit (for example, a pictographic display region) different from the display unit in the vicinity of the display unit (see Patent Document 1). Since the sub-display unit basically employs an active matrix system similar to that of the display unit, a general frame region is required. For this reason, the sub display section is provided in a dedicated area newly added to a general frame area.
Japanese Patent Laid-Open No. 2002-6787

  As described above, in the active matrix liquid crystal display device having the sub display section, a dedicated area for the sub display section must be newly provided in addition to the general frame area. Increases area. For this reason, the frame area remains as a useless area without being effectively used, and it is difficult to use it as a display device such as a mobile phone that is required to be downsized. In particular, in the conventional (partial or complete) driver monolithic type active matrix display device, since the frame area is wider for arranging the peripheral circuits, it is difficult to further reduce the size.

  The conventional driver monolithic active matrix display device does not have a different sub display unit in the vicinity of the display unit. This reason will be described with reference to FIG.

  FIG. 8 is a schematic plan view of the conventional driver monolithic display device and its TFT substrate as viewed from above in the direction perpendicular to the substrate surface. As shown to Fig.8 (a), the display apparatus has the frame area | region 92 which does not display in the display area 91 outer periphery. As shown in FIG. 8B, the TFT substrate corresponding to (that is, directly below) the frame region 92 includes a data driver 901, a gate driver 902, and a control unit 920 including a display control circuit. A peripheral circuit is arranged. The peripheral circuits are arranged in the frame region 92 in this way because the peripheral circuits that require a high degree of integration cannot be formed at positions that overlap the pixel circuits and the substrate surface in the vertical direction. Therefore, in the conventional driver monolithic display device, the same display as the display in the display area 91 cannot be performed in the frame area 92 where the peripheral circuits are arranged.

  Therefore, an object of the present invention is to provide a display device that can perform display in a frame area without newly providing a dedicated display area in addition to a generally required frame area. Another object of the present invention is to provide a (mono- or complete) driver monolithic display device capable of performing display in a frame region located in a direction perpendicular to the substrate surface from a peripheral circuit. .

According to a first aspect of the present invention, there are provided a plurality of pixel formation portions arranged in a matrix corresponding to intersections of a plurality of video signal lines and a plurality of scanning signal lines in the display portion for displaying an image, and the pixel formation A common electrode provided corresponding to the pixel electrode for applying a voltage or flowing a current between the substrate including the pixel electrode provided in a section and the pixel electrode, and the pixel electrode and the common electrode And an active matrix type comprising: a first electro-optic element that displays the image according to the voltage or the current; and a second electro-optic element that displays an image different from the image A display device,
The substrate includes a predetermined conductive region on a surface near the periphery,
The second electro-optic element is disposed between the conductive region and the common electrode, and is different from the image according to a voltage applied or a current flowing between the conductive region and the common electrode. An image is displayed.

According to a second invention, in the first invention,
The substrate receives an image signal representing the image, applies a voltage to the plurality of video signal lines in accordance with the image signal, and a scanning signal selectively drives the plurality of scanning signal lines. Including all or part of a peripheral circuit consisting of at least one of the line drive circuit and
The substrate includes the conductive region in a vicinity of a substantially vertical direction with respect to a substrate surface from a predetermined region where the peripheral circuit is formed.

According to a third invention, in the first or second invention,
Forming the image to be displayed on the second electro-optic element by partially blocking at least one of the light to the second electro-optic element and the light from the second electro-optic element It further includes a light shielding portion.

According to a fourth invention, in the third invention,
The light shielding portion is opened in a shape corresponding to the image to be displayed.

According to a fifth invention, in any one of the first to fourth inventions,
The second electro-optical element is a liquid crystal;
The conductive region is an electrode for reflective display.

According to a sixth invention, in the fifth invention,
The first electro-optic element is the same liquid crystal layer as the second electro-optic element.

In a seventh invention according to the first or second invention,
The conductive region has a shape corresponding to the image to be displayed.

The eighth invention is the first or second invention,
The substrate includes a conductive light-shielding region in the vicinity of a direction substantially perpendicular to the substrate surface from a predetermined region where the peripheral circuit is formed,
The conductive region is formed so as to electrically separate a predetermined portion of the light shielding region from a portion excluding the predetermined portion of the light shielding region.

In a ninth aspect based on the eighth aspect,
A portion of the light shielding region excluding the predetermined portion is electrically connected to the common electrode so that no voltage is applied to the common electrode or no current flows.

  According to the first aspect of the invention, an image displayed (in a matrix) by the first electro-optic element by the conductive region and the common electrode formed on the peripheral surface of the substrate including the plurality of pixel forming portions. An image different from that is displayed on the second electro-optical element. For example, a conductive region formed in a frame region in the vicinity of the periphery of the substrate, a substrate including a pixel electrode, and another substrate including a common electrode are opposed to each other, and the first and second electro-optical elements are opposed to these substrates. To display different images. With this configuration, it is possible to perform display in the frame area without providing a dedicated display area in addition to the generally required frame area.

  According to the second aspect, the image displayed by the first electro-optic element (in the form of a matrix) with the conductive region and the common electrode included in the substrate integrally including a plurality of pixel forming portions and peripheral circuits. An image different from that is displayed on the second electro-optical element. For example, the substrate including the conductive region and the pixel electrode formed immediately above the peripheral circuit and another substrate including the common electrode are opposed to each other, and the first and second electro-optical elements are sandwiched between these substrates, and different images are obtained. Is displayed. With this configuration, it is possible to perform display in a frame area in the vicinity of a substantially vertical direction with respect to the substrate surface from a predetermined area where the peripheral circuit is formed.

  According to the third aspect, at least one of the light to the second electro-optical element and the light from the second electro-optical element is partially blocked by the light-shielding portion, thereby displaying an image to be displayed. Form. With this configuration, the shape of the image to be displayed can be easily defined by the shape of the light shielding portion regardless of the shape of the conductive region or the like, so that display can be performed in the frame region easily and at low cost. Here, for example, when the light shielding portion is made of resin, it can be processed into a desired shape particularly easily at a low cost.

  According to the fourth aspect of the invention, the light shielding portion is opened in a shape corresponding to the image to be displayed. With this configuration, the shape of the image to be displayed can be very easily defined by the shape of the opening regardless of the shape of the conductive region, etc., so that display can be performed in the frame region more easily and at low cost. Can do.

  According to the fifth aspect of the invention, since the conductive region for applying a voltage to the second electro-optic element that is a liquid crystal is an electrode for reflective display, other dedicated display regions in the frame region near the periphery of the substrate. Reflective display can be performed without providing a new one. Further, in this configuration, even in the case where a peripheral circuit is formed in the substrate, for example, in a frame region near the substrate surface in a direction substantially perpendicular to the substrate surface from the predetermined region where the peripheral circuit is formed by the reflective electrode. Reflective display can be performed.

  According to the sixth aspect, since the first electro-optic element and the second electro-optic element are the same liquid crystal layer, a display device can be manufactured at a low cost in the same process without adding a new process. Can be manufactured.

  According to the seventh aspect, since the conductive area has a shape corresponding to the image to be displayed, display according to the shape of the conductive area (for example, segment display) can be performed.

  According to the eighth aspect of the invention, since the conductive region is formed so as to electrically separate the predetermined portion of the light shielding region from the remaining light shielding region portion, the conductive region is electrically conductive from the already formed light shielding region by, for example, an etching process. An area can be created easily and at low cost.

  According to the ninth aspect, the portion other than the conductive region of the light shielding region is electrically connected to the common electrode so that no voltage is applied to the common electrode or no current flows. Thus, unnecessary display such as stray light can be blocked by performing black display, for example, so that the function of the light shielding region can be assisted.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<1. First Embodiment>
<1.1 Overall configuration and operation>
First, the overall configuration and operation of the liquid crystal display device according to the first embodiment of the present invention will be described. The liquid crystal display device of this embodiment includes a circuit similar to the pixel circuit in the conventional driver monolithic display device shown in FIG. 8, but the circuit corresponding to the peripheral circuit is provided outside the liquid crystal panel. It is not a driver monolithic display device. Further, unlike the conventional display device, a configuration to be described later for performing display in the frame area is newly included.

  FIG. 1 is a block diagram showing the configuration of the liquid crystal display device according to this embodiment together with an equivalent circuit of the display unit. Like the conventional active matrix liquid crystal display device, this liquid crystal display device includes a data driver 101 as a video signal line driving circuit, a gate driver 102 as a scanning signal line driving circuit, an active matrix main display unit 103, and the like. A main display control circuit 210 for controlling the data driver 101 and the gate driver 102. The liquid crystal display device further includes a sub display unit 300 for performing display in the sub display region 30 and a sub display control circuit 220 for controlling display in the sub display unit 300.

  The main display unit 103 has the same configuration as a conventional display unit. In other words, the main display unit 103 includes gate lines GL1 to GLm as a plurality (m lines) of scanning signal lines, and a plurality (n lines) of video signal lines that intersect with each of the gate lines GL1 to GLm. Data lines SL1 to SLn, and a plurality (m × n) of pixel forming portions provided corresponding to the intersections of the gate lines GL1 to GLm and the data lines SL1 to SLn, respectively.

  These pixel formation portions are arranged in a matrix to form a pixel array, and each pixel formation portion is connected to a gate line GLj that passes through a corresponding intersection and a data line SLk that passes through the intersection. The TFT 11 that is a switching element to which a source terminal is connected, the pixel electrode that is connected to the drain terminal of the TFT 11, the common electrode Ec that is a common electrode provided in the plurality of pixel formation portions, and the plurality And a liquid crystal layer sandwiched between the pixel electrode and the common electrode Ec. If necessary, an auxiliary capacitor is provided in parallel with the capacitor formed by the pixel electrode and the common electrode Ec. Is added. A pixel capacitor Cp is configured by a capacitor formed by the pixel electrode and the common electrode Ec (a capacitor obtained by adding an auxiliary capacitor to the capacitor if an auxiliary capacitor is added). For convenience of explanation, the pixel circuit including the TFT 11 is also referred to as a pixel formation portion.

  Since the display device according to the present embodiment is not a driver monolithic type, the peripheral circuit including the data driver 101, the gate driver 102, and the control unit 200 including the display control circuit is provided outside the liquid crystal panel. ing. Hereinafter, a specific structure of the pixel formation portion and the frame region will be described with reference to FIG.

  FIG. 2 is a cross-sectional view perpendicular to the substrate surface showing a structural example of the pixel forming portion in the vicinity of the TFT 11 and in the vicinity of the frame region. For these TFTs, continuous grain silicon (hereinafter, abbreviated as “CG silicon”), which is polycrystalline silicon having higher crystallinity than ordinary polycrystalline silicon (Poly Silicon), is used. In place of this CG silicon, other polycrystalline silicon or amorphous silicon may be used.

  Here, a region A shown in FIG. 2 is a region where a part of the pixel formation portion is formed, and a region B is a general frame region. An area a1 in the area A indicates a reflective display area for performing reflective display described later, and an area a2 in the area A indicates a transmissive display area for performing transparent display described later.

  The display device includes a TFT substrate 40, a CF substrate 41, and a liquid crystal layer 42 provided so as to be sandwiched between these substrates. Since the liquid crystal layer 42 is configured to be provided not only in the region A but also in the region B in the same process, the device can be easily manufactured. Conventionally, the liquid crystal layer 42 is often provided not only in the region A but also in the region B. Therefore, in the configuration of the present embodiment, the conventional display device can be used as it is. Note that the liquid crystal layer provided in the region A and the liquid crystal layer provided in the region B may be different.

  This display device is a display (hereinafter referred to as “transmission display”) using transmitted light from a backlight illumination device (not shown) provided at a position opposite to the CF substrate 41 at a position facing the TFT substrate 40. This is a so-called transflective display device that simultaneously performs display using external light incident through the CF substrate 41 from the outside of the device (hereinafter referred to as “reflective display”). This transflective display device can provide an easy-to-see display mainly by transmissive display in a dark place and mainly by reflective display in a bright place.

  The CF glass substrate 61 is provided with a polarizing plate (not shown) on the outer side (the side opposite to the TFT substrate 40), and the pixels formed by the pixel forming portions on the inner side (side facing the TFT substrate 40). A color filter layer 65 made of a resin that transmits light corresponding to the colors is provided. The polarizing plate may include an optical functional film other than the polarizing film such as a retardation film and an optical compensation film.

  Further, a light shielding resin layer 66 functioning as a light shielding film is provided inside the color filter layer 65 in the region B shown in FIG. The light shielding resin layer 66 may be replaced with a light shielding material such as a metal film. Conventionally, there is a configuration in which a later-described reflective conductive film 72 functions as a light shielding film. This configuration will be described in detail in the second embodiment. In general, in a display device of a transmissive display type or a transflective display type, light emitted from the backlight illumination device does not leak from the frame region 20 or external light is not reflected, and a peripheral circuit is provided in the frame region 20. When provided, a light-shielding film for covering the frame region 20 is provided in order to prevent external light from passing through the CF substrate 41 and the liquid crystal layer 42 and hitting this peripheral circuit to change the electrical characteristics of the TFT. ing. Similarly, a light shielding resin layer 66 is also provided inside the color filter layer 65 in the region A shown in FIG. Since this light shielding resin layer 66 is provided so as to cover the TFTs of the pixel circuit and the like, unlike the light shielding resin layer 66 in the region B, it is provided only in the vicinity of the boundary region of the pixel (that is, the portion to be the pixel is an opening). Have been). Further, a transparent resin layer 67 is provided further inside the reflective display area a1 and area B.

  Further, on the glass substrate 61 for CF, a transparent conductive film 71 made of ITO (Indium Tin Oxide) is formed over almost the entire area A and area B in contact with the inner liquid crystal layer 42. The transparent conductive film 71 functions as the common electrode Ec.

  As shown in FIG. 2, a CG silicon thin film 52 is formed as an active layer in the region A of the TFT glass substrate 60, and a gate electrode 51 and an interlayer insulating film 54 are formed with a gate insulating film 53 interposed therebetween. . Thereafter, two contact portions are opened so that the CG silicon thin film 52 is exposed, and a wiring layer 55 including a drain electrode and a source electrode of the TFT is formed in these contact portions. The wiring layer is a metal laminated film in which, for example, tantalum (Ta) and tantalum nitride (TaN) are laminated. Further, a passivation film 56 for passivation and a planarizing film 57 for planarizing the surface are formed thereon, and further contact portions are formed so that the wiring layer 55 corresponding to the drain electrode is exposed. Opened. A transparent conductive film 70 made of ITO (Indium Tin Oxide) is formed in the entire region A (excluding the region B). The transparent conductive film 70 functions as a pixel electrode. Note that the transparent conductive film 70 may also be formed over the entire region B. Further, a reflective conductive film 72 made of a conductive material such as aluminum (Al) or silver (Ag) having a high light reflectivity (and light shielding property) is formed on the entire region A and region B by sputtering or the like. Etching and removing the reflective conductive film 72 in the region B and the reflective conductive film 72 in the transmissive display region a2 in the region A by using a photoresist patterned in a shape corresponding to the region other than the reflective display region a1 in the region A To do. Thereby, the reflective conductive film 72 is formed in the reflective display area a1.

  As shown in FIG. 2, a wiring layer 75 made of a metal laminated film similar to the wiring layer is formed in the region B of the TFT glass substrate 60. In order to arrange the wiring layer 75 in the liquid crystal panel, the region B which is a frame region is indispensable. Note that a passivation film 56 may be provided between the wiring layer 75 and the planarizing film 57, and a film for preventing electrolytic corrosion is provided between the transparent conductive film 70 and the reflective conductive film 72 as necessary. It may be formed.

  Furthermore, as shown in FIG. 2, the length (thickness) in the direction perpendicular to the substrate surface of the CF substrate 41 in the reflective display region a1 and region B is increased by providing the transparent resin layer 67. This is to prevent the display (brightness) from changing in either the transmissive display or the reflective display in the pixel formation portion. That is, the voltage applied or the current flowing between the transparent conductive film 70 in the transmissive display region a2 and the transparent conductive film 71 that is the common electrode is the transparent conductive film that is the common electrode and the reflective conductive film 72 in the reflective display region a1. 71 is equal to the voltage or current flowing between the liquid crystal layer 42 and the liquid crystal layer 42 generated in the light passing through the liquid crystal layer 42 by equalizing the optical path length of the light passing through the liquid crystal layer corresponding to both display regions. The phase difference of the electric field component between the slow axis and the advancing axis of the light just before entering, and the phase difference of the electric field component between the slow axis and the advancing axis of light just after passing through the liquid crystal layer 42, The vertical length (thickness) of the liquid crystal layer 42 in the transmissive display area a2 is set to the thickness in the reflective display area a1 so that the difference between the transmissive display area a2 and the reflective display area a1 is equal. Set to approximately twice that.

  Next, a driving method and a driving circuit for the main display unit 103 of the present embodiment having the above configuration will be described below. In the present embodiment, image data Dv, which is data representing an image to be displayed on the liquid crystal panel, including data for determining the timing of the display operation and the like is sent to the main display control circuit 210 from a CPU or the like in an external computer.

  The main display control circuit 210 receives the image data Dv, and as a signal for causing the main display unit 103 to display an image represented by the image data Dv, a data driver start pulse signal and a clock signal, and an image to be displayed. Generates and outputs a data driver control signal CD including a digital image signal indicating a gate driver control signal CG including a start pulse signal and a clock signal for a gate driver, and a predetermined polarity switching control signal φ described later. . As the polarity switching control signal φ, the synchronization signal included in the image data Dv may be used as it is.

  The data driver 101 generates data signals S (1) to S (n) as analog voltages corresponding to pixel values in each horizontal scanning line of the image represented by the digital image signal based on the data driver control signal CD including the digital image signal. The data signals S (1) to S (n) are sequentially generated for each horizontal scanning period and applied to the data lines SL1 to SLn, respectively. In the data driver 101 in the present embodiment, the polarity of the voltage applied to the liquid crystal layer is inverted every frame period, and is also inverted every horizontal scanning line in each frame. A driving method in which S (n) is output, that is, a line inversion driving method is employed.

  Instead of this line inversion driving method, a frame inversion method in which the polarity is inverted every frame period may be adopted. From the viewpoint of improving display quality, in addition to the line inversion driving method, a driving method that reverses the polarity of the voltage applied to the liquid crystal layer for each data line (each vertical line), that is, a dot inversion driving method is adopted. May be. That is, the data driver 101 may output the data signals S (1) to S (n) so that the polarity of the voltage applied to the data lines SL1 to SLn is inverted for each data line. Further, the data driver 101 may be configured to sequentially latch input analog image signals and sequentially apply them to the data lines SL1 to SLn as data signals S (1) to S (n).

  The gate driver 102 sequentially selects the gate lines GL1 to GLm in each frame period (each vertical scanning period) of the digital image signal based on the gate driver control signal CG, and an active gate signal (TFT11) is applied to the selected gate line. Is applied). In the main display unit 103, when each of the gate lines GL1 to GLm is selected within each frame period, each TFT 11 whose gate terminal is connected to the selected gate line GLj is turned on in each selection period. . As a result, a voltage corresponding to the value of the corresponding pixel in the image represented by the digital image signal is held in the pixel capacitor Cp connected to the drain terminal of each TFT 11.

  By the data driver 101 and the gate driver 102, in the main display unit 103, the data signals S (1) to S (n) are applied to the data lines SL1 to SLn, respectively, and the gate signal G is applied to the gate lines GL1 to GLm. (1) to G (m) are respectively applied. As a result, the voltage corresponding to the value of the corresponding pixel in the image represented by the digital image signal is given to the pixel capacitance Cp of each pixel forming unit in the main display unit 103 by the data signals S (1) to S (n). A voltage corresponding to the potential difference between the pixel electrode and the common electrode Ec is applied to the liquid crystal layer in accordance with the digital image signal. That is, the voltage held in each pixel capacitor Cp becomes the voltage applied to the corresponding liquid crystal portion. Note that the potential of the common electrode Ec is given by a common electrode driving circuit (not shown), and this common electrode driving circuit responds to a polarity switching control signal φ from the main display control circuit 210 for one frame (one vertical scan). A voltage that switches between two types of reference voltages in a period) is generated, and this voltage is supplied to the common electrode Ec of the CF substrate as the potential of the common electrode Ec.

  The main display unit 103 displays the image represented by the digital image signal, that is, the image represented by the digital video signal received from an external signal source or the like, by controlling the light transmittance of the liquid crystal layer by the applied voltage.

  The configuration and operation of the data driver 101, the gate driver 102, and the main display control circuit 210 are the same as those of the conventional display device. However, as described above, the sub display unit 300 includes the light shielding resin layer 66 in the region B. While being used as a light-shielding film as in the prior art, it is used for reflective display using the reflective conductive film 72 in the region B as a reflective electrode. The configuration and operation of the sub display unit 300 and the sub display control circuit 220 that controls display by the sub display unit 300 will be described with reference to FIGS. 3 and 4.

<1.2 Configuration and Operation of Sub Display Unit>
FIG. 3 is a plan view showing a display example displayed in the sub display area by the sub display unit. FIG. 4 is a diagram showing a structural example for performing reflective display in the sub display section. More specifically, FIG. 4A is an enlarged view of a part of the reflective conductive film 72 serving as the sub display section. FIG. 4B is a plan view illustrating an example of a structure in which a part of the light shielding resin layer 66 serving as a sub display unit is enlarged.

  Here, the example shown in FIG. 3 is a display example when the present display device is built in a mobile phone, and the figures in the figure are, in order from the left, the electric field strength of the radio wave to be received and out of the talking area. , Time, and remaining battery level. For example, when the electric field strength is at the lowest level at which communication is possible, only the graphic element imitating the left antenna is displayed among the four graphic elements constituting the graphic, and the electric field strength increases. As a result, the graphic elements displayed among these graphic elements increase one by one from the left. FIG. 4 shows the structure of the four electrodes forming the graphic showing the electric field strength composed of these four graphic elements and the opening of the corresponding light shielding resin layer.

  That is, the first electrode 721 shown in FIG. 4A is a reflective electrode (electrode for reflection display) for displaying a graphic element imitating the left antenna among the four graphic elements, and the second To fourth electrodes 722 to 724 are reflective electrodes for displaying the remaining graphic elements.

  However, among these electrode shapes, in particular, the shape of the first electrode 721 cannot display a figure imitating a desired antenna. Therefore, an opening having a shape corresponding to the above four graphic elements is provided in the light shielding resin layer 66, and a graphic having a desired shape is displayed by light passing through the opening. FIG. 4B shows first to fourth openings 661 to 664 which are these openings. In addition, the dotted line in the figure has shown the said 1st-4th electrodes 721-724 corresponding to these opening parts.

  Thus, since the displayed graphic is defined by the shape of the opening including the first to fourth openings 661 to 664 formed in the light shielding resin layer 66, the graphic for displaying these graphics is displayed. The first to fourth electrodes 721 to 724, which are reflective electrodes, have a size necessary for display, and have a shape that does not leak light that prevents desired display from an opening other than the corresponding opening. If there is, the shape is not limited. Therefore, since the processing accuracy is not required, it is possible to make the reflective electrode for these displays a simple structure.

  Note that the reflective conductive film 72 around the first to fourth electrodes 721 to 724 is removed by, for example, an etching process, and the first to fourth electrodes 721 to 724 are sub-display controlled. The circuits 220 are connected to each other by predetermined wiring (not shown). Here, the reflective electrode portion corresponding to the wiring does not contribute to display because it is hidden by the light shielding resin layer 66. Therefore, it is not necessary to make these wiring portions particularly thin (that is, to reduce the area) as in the case of the second embodiment described later. This also makes it possible to make the reflective electrode have a simple structure.

  The sub display control circuit 220 receives sub display data Ds including an instruction to appropriately display each graphic element in accordance with the electric field strength of the received radio wave from the outside of the apparatus (for example, a control unit of the mobile phone main body), and this sub display data Ds. Based on the above, the respective voltage values to be applied to the first to fourth electrodes 721 to 724 are determined, and the determined voltage is applied to the corresponding electrodes. These voltage values are based on the polarity switching control signal φ given from the main display control circuit 210, and when the reflective display is performed by the first to fourth electrodes 721 to 724, the potential of the common electrode (transparent conductive film) In the case where a predetermined potential for display (typically a potential for white display in a normally black display device) that gives a predetermined potential difference with reference to (71 potential) is applied and reflection display is not performed. A predetermined potential for non-display that is the same potential as the common electrode (typically a potential for black display in a normally black display device) is applied. Then, in accordance with the control of the sub display control circuit 220, the graphic shown in FIG.

  Also, for example, the reflective conductive film 72 around the first to fourth electrodes 721 to 724 is replaced with the first to fourth electrodes 721 to 724 and the reflective conductive film 72 (in the region B shown in FIG. 2). The reflective conductive film 72 around the first to fourth electrodes 721 to 724 may be partially removed by, for example, an etching process so that they are separated from each other with a very narrow interval. Thus, by electrically connecting the remaining reflective conductive film 72 electrically disconnected from the first to fourth electrodes 721 to 724 and the transparent conductive film 71 that is a common electrode, the reflective conductive film 72 The potential is set to the same potential as that of the common electrode. In this case, it is possible to prevent the remaining reflective conductive film 72 from performing unnecessary reflective display (due to a potential difference from the potential of the common electrode). Furthermore, by making the potential of the reflective conductive film 72 equal to the potential of the common electrode and performing black display in that portion, unnecessary light such as stray light from the main display region 10 can be blocked, for example. The function of the light shielding resin layer 66 as a light shielding film can be assisted.

  As described above, the opening including the first to fourth openings 661 to 664 formed in the light shielding resin layer 66, the reflective electrode including the first to fourth electrodes 721 to 724, and the common electrode With the transparent conductive film 71, the sub-display unit 300 performs reflection display by a so-called segment method (or static drive method). In this segment system display, the above-described pixel circuit and matrix wiring included in the main display portion 103 that performs display by the active matrix system are not necessary, so that display can be easily performed. In addition, the sub display unit 300 performs reflection display by a so-called passive matrix method by performing wiring crossing each other in a matrix form (viewed from above) with the liquid crystal layer sandwiched between the upper part of the peripheral circuit and the common electrode part corresponding thereto. May be performed. Further, the sub display control circuit 220 may perform gradation control in which the predetermined potential given for display is changed stepwise so that gradation display is possible.

<1.3 Effect>
As described above, the liquid crystal display device according to the present embodiment includes the first to fourth openings including the first to fourth openings 661 to 664 formed in the light shielding resin layer 66 functioning as a light shielding film. By using the electrodes 721 to 724 (that is, a part of the reflective conductive film 72 in the region B shown in FIG. 2), a dedicated display region is newly provided in addition to the generally required frame region. In general, the reflective display (by the segment method) can be performed in the frame area 20 that does not contribute to the display. Therefore, in general, a frame area that does not contribute to display can be used effectively, and the device can be made smaller than the conventional configuration in which a new display area is provided. It becomes easy to use as a display device.

  In addition, the openings including the first to fourth openings 661 to 664 formed in the light shielding resin layer 66 can be easily formed to have a desired shape, and the fifth display that performs this reflective display. To 8th electrodes 725 to 728 need only have a simple structure (in addition, it is not necessary to make the reflective electrode portion corresponding to the wiring thin), so that the sub display portion can be easily and inexpensively created. be able to.

<2. Second Embodiment>
<2.1 Overall configuration and operation>
Next, the overall configuration and operation of the liquid crystal display device according to the second embodiment of the present invention will be described. The liquid crystal display device of this embodiment includes a circuit similar to the pixel circuit and the peripheral circuit in the conventional driver monolithic type display device shown in FIG. 8, and has a new configuration to be described later for displaying in the frame area. Contains. A block diagram showing the configuration of the liquid crystal display device according to the present embodiment together with an equivalent circuit of the display unit is the same as that in FIG.

  FIG. 5 is a schematic plan view of the driver monolithic display device and the TFT substrate according to the present embodiment as viewed from above in the direction perpendicular to the substrate surface. As shown in FIG. 5A, the display device has a frame area 20 on the outer periphery of the main display area 10, and the frame area 20 includes a sub display area 30 for performing display. Yes. As shown in FIG. 5B, a peripheral circuit including a data driver 101, a gate driver 102, and a control unit 200 including a display control circuit is arranged on the TFT substrate corresponding to the sub display area 30. In the figure, an example is shown in which the control unit 200 is arranged directly below the sub display area 30. It should be noted that a part or all of the peripheral circuit may be arranged immediately below the sub display area 30, for example, a part of the data driver 101 may be arranged.

  FIG. 6 is a cross-sectional view perpendicular to the substrate surface showing a structural example of the vicinity of the TFT 11 and the frame region in the pixel formation portion. Since the configuration of the TFT 11 is the same as the configuration of the TFT 11 of the pixel formation portion in the first embodiment, detailed description thereof is omitted. Note that it is preferable to use the above-described CG silicon having a high electron mobility (particularly, low-temperature CG silicon that can be formed at a low temperature) for a driver monolithic display device such as the display device in the present embodiment. Polycrystalline silicon or amorphous silicon may be used.

  Here, a region A shown in FIG. 6 is a region where a part of the pixel formation portion is formed, and a region B is formed with a part of the peripheral circuit unlike the region in the first embodiment where the wiring is formed. It is an area to be done. An area a1 in the area A indicates a reflective display area for performing reflective display described later, and an area a2 in the area A indicates a transmissive display area for performing transparent display described later.

  As shown in FIG. 6, the CF glass substrate 61 in this region B is not provided with the light shielding resin layer 66 functioning as a light shielding film on the inner side (side facing the TFT substrate 40). In this embodiment, as will be described later, the reflective conductive film 72 functions as a light shielding film. The reflective conductive film 72 is formed as follows, for example. That is, a reflective conductive film 72 made of a conductive material such as aluminum (Al) or silver (Ag) having a high light reflectance (and light shielding property) is formed on the entire region A and region B by a sputtering method or the like. By using a photoresist patterned in a shape corresponding to a region other than the reflective display region a1 in A, the reflective conductive film 72 in the transmissive display region a2 in the region A is etched away. In this manner, the reflective conductive film 72 is formed in the reflective display area a1 and the area B.

  As described above, only the reflective conductive film 72 is formed in the region B. Since this region B is in the frame region 20 as shown in FIG. 5, the reflective conductive film 72 in the region B is irrelevant to the (reflection) display by the main display unit 103, but the light shielding property of the frame region 20. It functions as a light-shielding film for ensuring. That is, in the transmissive display type or transflective display type display device, the light emitted from the backlight illumination device does not leak from the frame region 20 through the gaps between the elements included in the peripheral circuit and the like. In order to prevent the electrical characteristics of the TFT from changing due to the light from the light passing through the CF substrate 41 and the liquid crystal layer 42 and hitting the peripheral circuit, a light shielding film for covering the frame region 20 is required. If the reflective conductive film 72 in the region B is formed simultaneously with the reflective conductive film 72 in the region A as this light-shielding film, it is not necessary to newly form another light-shielding film. Thus, it has been known that the reflective conductive film 72 in the region B can be used as a light shielding film. This display device is characterized in that the reflective conductive film 72 in the region B is used for reflective display in the sub-display region 30 while using the reflective conductive film 72 in the region B as a conventional light shielding film. This detailed configuration will be described later.

  In the region B, not only the reflective conductive film 72 is laminated, but also a transparent conductive film 70 may be laminated on (or under) the reflective conductive film 72. Further, in order to cover the TFT of the pixel circuit and the like, a color filter layer 65 having a pattern for shielding the part may be used, or a light shielding resin layer 66 similar to that of the first embodiment may be provided. .

  As described above, the sub display unit 300 uses the reflective conductive film 72 in the region B shown in FIG. 6 that is used as the light shielding film in the frame region 20 for reflective display. The configuration and operation of the sub display unit 300 and the sub display control circuit 220 that controls display by the sub display unit 300 will be described with reference to FIG.

<2.2 Configuration and operation of sub-display unit, etc.>
FIG. 7 is a plan view showing a structural example in which a part of the reflective conductive film 72 serving as the sub display portion is enlarged. The display example displayed in the sub display area by the sub display unit is an example shown in FIG. 3, that is, a display example when the display device is built in a mobile phone. FIG. 7 shows the structure of four electrodes forming the graphic showing the electric field strength composed of four graphic elements constituting the graphic showing the electric field strength.

  That is, the fifth electrode 725 shown in FIG. 7 is a reflection electrode (electrode for reflection display) for displaying a graphic element imitating the left antenna among the four graphic elements, and is from the sixth to the eighth. The electrodes 726 to 728 are reflective electrodes for displaying the remaining graphic elements. The fifth to eighth electrodes 725 to 728 and the entire reflective conductive film 72 (in the region B shown in FIG. 6) are separated with a very narrow space therebetween. The reflective conductive film 72 around 725 to 728 is partially removed by, for example, an etching process. The fifth to eighth electrodes 725 to 728 are electrically separated from the entire reflective conductive film 72 by a very thin strip-shaped nonconductive region formed as a result of this removal. Therefore, the fifth to eighth electrodes 725 to 728 can be set to a desired potential different from that of the reflective conductive film 72.

  Specifically, among these fifth to eighth electrodes 725 to 728, each electrode portion that is formed to be very thin (to the extent that it is difficult to distinguish with the naked eye) extends downward in the figure. These are connected by predetermined wirings not shown. Note that the electrode portion extending downward is very thin (that is, has a small area), so that reflective display is not performed, and the display shape of the graphic is not impaired. Further, since the non-conductive region is very thin (area is small), the function of the reflective conductive film 72 as a light-shielding film is not impaired.

  Further, instead of the configuration in which the lower portions of the fifth to eighth electrodes 725 to 728 are formed very thin as described above, the CF substrate 41 corresponding to each of these electrode portions (that is, facing the vertical direction) The transparent conductive film 71 may not be provided (for example, partially removed). In this configuration, no voltage is applied to the liquid crystal layer in contact with each of the electrode portions, so that reflective display is not performed, and the display shape of the graphic is not impaired. Further, the function of the reflective conductive film 72 as a light shielding film is not impaired.

  Further, for example, by electrically connecting the reflective conductive film 72 and the transparent conductive film 71 that is a common electrode, the potential of the reflective conductive film 72 is set to the same potential as that of the common electrode. In this way, it is possible to prevent the reflective conductive film 72 shown in FIG. 7 from performing unnecessary reflective display (due to a potential difference from the potential of the common electrode). Furthermore, by making the potential of the reflective conductive film 72 equal to the potential of the common electrode and performing black display in that portion, unnecessary light such as stray light from the main display region 10 can be blocked, for example. The function of the reflective conductive film 72 as a light shielding film can be assisted. Note that the two regions of the reflective conductive film 72 surrounded by the fifth electrode 725 shown in FIG. 7 are electrically connected to the entire other reflective conductive film 72 by a very thin electrode (not shown). Here, you may comprise so that the reflective film 72 whole may be electrically connected by changing the shape of the graphic element imitating the said antenna.

  As described above, the sub-display unit 300 performs the reflective display by the so-called segment system (or static drive system) by the reflective electrode including the fifth to eighth electrodes 725 to 728 and the transparent conductive film 71 as the common electrode. . In this segment system display, the above-described pixel circuit and matrix wiring included in the main display portion 103 that performs display by the active matrix system are unnecessary, and therefore it is easy to use an extremely thin portion directly above the peripheral circuit. Can be displayed. In addition, the sub display unit 300 performs reflection display by a so-called passive matrix method by performing wiring crossing each other in a matrix form (viewed from above) with the liquid crystal layer sandwiched between the upper part of the peripheral circuit and the common electrode part corresponding thereto. May be performed. Further, the sub display control circuit 220 may perform gradation control in which the predetermined potential given for display is changed stepwise so that gradation display is possible.

<2.3 Effects>
As described above, in the driver monolithic liquid crystal display device according to the second embodiment, a part of the reflective conductive film 72 in the region B shown in FIG. 6 that functions as a light shielding film is used for the reflective display shown in FIG. By using them as the fifth to eighth electrodes 725 to 728, the reflective display can be performed (by the segment system) in the frame region 20 located in the direction perpendicular to the substrate surface from the peripheral circuit. . Further, the fifth to eighth electrodes 725 to 728 for performing the reflective display can be easily and inexpensively produced from the already formed reflective conductive film 72 by, for example, etching.

<3. Modification>
In the display device according to the first embodiment, a circuit corresponding to a peripheral circuit is provided outside the liquid crystal panel by a TCP (Tape Carrier Package) method, a COF (Chip On Flexible) method, or the like. A configuration in which the circuit is not integrally formed with the circuit on the TFT substrate (that is, not a driver monolithic type) is arranged on the substrate, for example, a COG (Chip On Glass) configuration.

  In the display device according to the first embodiment, openings such as the first to fourth openings 661 to 664 are formed in the light shielding resin layer 66 functioning as a light shielding film. However, by leaving the portion of the light shielding resin layer 66 corresponding to these openings and removing the surrounding light shielding resin layer 66, the remaining portion of the light shielding resin layer 66 is displayed darkly and the periphery thereof is displayed brightly. May be. Further, by providing a resin layer that transmits a predetermined color in the opening or a region corresponding to the periphery thereof, the portion may be displayed in a predetermined color.

  Although all the peripheral circuits included in the display device in the second embodiment are formed in the TFT substrate 40, a part of the peripheral circuits may be provided outside the liquid crystal panel. For example, the main display control circuit 210 or a part of the circuit constituting the main display control circuit 210 may be provided outside. Further, the sub display control circuit 220 included in the display device according to the second embodiment is included in the peripheral circuit and formed in the TFT substrate 40, but may be provided outside the liquid crystal panel. In this configuration, for example, among the first to fourth electrodes 721 to 724 shown in FIG. 7, each of the very thin electrode portions extending downward in the drawing is extended to the vicinity of the outer extension of the TFT substrate 40, and there To the external sub-display control circuit 220. Therefore, according to this configuration, the TFT substrate 40 can be easily formed only by forming the sub-display unit 300 (by an etching process or the like) on the conventional TFT substrate.

  The display device according to the second embodiment performs reflective display using the reflective electrodes including the fifth to eighth electrodes 725 to 728 having the shape of a graphic to be displayed, and the display device according to the first embodiment. Performs reflective display through openings including first to fourth openings 661-664 having the shape of the graphic to be displayed. However, in the display device according to the second embodiment, the reflective display may be performed through an opening having a shape of a graphic to be displayed, as in the case of the first embodiment. In the display device according to the first embodiment, the reflective display may be performed by the reflective electrode having the shape of the graphic to be displayed as in the case of the second embodiment.

  The display device in the first and second embodiments is a transflective display type liquid crystal display device, but may be a reflective display type liquid crystal display device or applied to a transmissive display type liquid crystal display device. Is possible. Note that when applied to a transmissive liquid crystal display device, a part of the conductive film corresponding to the reflective conductive film 72 is used as a reflective electrode as shown in FIG. It is possible. In this configuration, a structure for thinning the liquid crystal layer of the portion so that the display luminance of the sub display region 30 is not much darker than the display luminance of the main display portion 103, specifically, the substrate of the liquid crystal layer 42 of the portion. It is preferable to increase the thickness of the CF substrate 41 with respect to the substrate surface in the region B as shown in FIG. 6 so that the length (thickness) in the direction perpendicular to the surface is approximately half of the thickness in the transmissive display region. is there. In addition, in order to increase the thickness of the CF substrate 41 with respect to the substrate surface in this way, in addition to the configuration in which the transparent resin 67 is added to the portion where the thickness is to be increased, any known configuration is used. Good.

  The display device in the first and second embodiments includes a liquid crystal between the transparent conductive film 71 included in the CF substrate 41 that is a common electrode and the transparent conductive film 70 or the reflective conductive film 72 included in the TFT substrate 40. A so-called IPS (In-Plane Switching) type display device in which the transparent conductive film 71 included in the CF substrate 41 is omitted and a common electrode is formed on the TFT substrate 40 instead. It may be.

  The display devices in the first and second embodiments use a liquid crystal for the pixel formation portion, but use an electro-optical element other than the liquid crystal for the entire pixel formation portion (or other than the portion corresponding to the sub display portion). May be. Here, the electro-optical element is an organic EL (Eelectro Luminescence) element, FED (Field Emission Display), LED (light emitting diode), charge driving element, liquid crystal, E ink (Electronic Ink), etc. All elements whose general characteristics change shall be said. In this configuration, instead of the liquid crystal layer, for example, a light emitting layer (electro-optical layer) that emits light when supplied with an electric current is used, and this light emitting layer is typically sandwiched between two electrodes in the same manner as described above. . Note that the light emitting layer is not necessarily sandwiched as in the IPS method.

  Here, when this light emitting layer functions as an organic EL element, it replaces with the transparent conductive film 70 (and reflective conductive film 72) shown in FIG. 6, and the metal electroconductivity used as the anode (anode electrode) of an organic EL element. A layer is formed, and the transparent conductive film 71 becomes a cathode (cathode electrode) of the organic EL element. In this structure, light does not pass through the TFT glass substrate 60 by the metal conductive layer, and light is emitted in the direction of the CF glass substrate 61. Such a structure is called a top emission structure, but in the bottom emission structure in which the metal conductive layer serving as the anode electrode and the transparent conductive film 71 serving as the cathode electrode are interchanged, the direction of the TFT glass substrate 60 is Give off light. Therefore, in the configuration of the second embodiment, it is difficult to display in the frame area 20 including the peripheral circuit, and thus the top emission structure is preferable. In the configuration of the first embodiment, even the bottom emission structure is not particularly problematic.

It is a block diagram which shows the structure of the liquid crystal display device which concerns on 1st Embodiment in this invention with the equivalent circuit of the display part. It is sectional drawing of the orthogonal | vertical direction with respect to the substrate surface which shows the structural example of TFT vicinity of the pixel formation part in the said embodiment, and a frame area | region. It is a figure which shows the structural example for performing the example of a display of the subdisplay part in the said embodiment, and reflective display. It is a figure which shows the structural example for performing the example of a display of the subdisplay part in the said embodiment, and reflective display. It is the typical top view which looked at the driver monolithic type display device concerning the 2nd embodiment in the present invention, and its TFT substrate from the perpendicular direction to the substrate surface. It is sectional drawing of the orthogonal | vertical direction with respect to the substrate surface which shows the structural example of TFT vicinity of the pixel formation part in the said embodiment, and TFT vicinity of a peripheral circuit. It is a figure which shows the structural example for performing the reflective display of the subdisplay part in the said embodiment. It is the typical top view which looked at the conventional driver monolithic type display device and its TFT substrate from the upper direction perpendicular to the substrate surface.

Explanation of symbols

10: Main display area 11: Thin film transistor (TFT)
DESCRIPTION OF SYMBOLS 20 ... Frame area 30 ... Sub-display area 40 ... TFT substrate 41 ... CF substrate 42 ... Liquid crystal layer 51 ... Gate electrode 52 ... Silicon thin film 53 ... Gate insulating film 54 ... Interlayer insulating film 55 ... Wiring layer 56 ... Passivation film 57 ... Flat Chemical conversion film 60 ... TFT glass substrate 61 ... CF glass substrate 65 ... Color filter layer 66 ... Light shielding resin layer 67 ... Transparent resin layer 70, 71 ... Transparent conductive film 72 ... Reflective conductive film 101 ... Data driver 102 ... Gate driver 103 ... main display section 200 ... control section 210 ... main display control circuit 220 ... sub display control circuit 300 ... sub display sections 661 to 664 ... first to fourth openings 721 to 728 ... first to eighth (reflection) Electrode CD ... Data driver control signal CG ... Gate driver control signal φ ... Polarity switching control signal Cp ... Pixel capacitance Ds: Sub display data Dv: Image data Ec: Common electrode GL1 to GLm: Gate line (scanning signal line)
G (1) to G (m)... Gate signal (scanning signal)
SL1 to SLn: Data line (video signal line)
S (1) to S (n)... Data signal (video signal)

Claims (9)

A plurality of pixel formation portions arranged in a matrix corresponding to intersections of a plurality of video signal lines and a plurality of scanning signal lines in a display portion for displaying an image, and pixels provided in the pixel formation portions A common electrode provided corresponding to the pixel electrode to apply a voltage or flow a current between the substrate including the electrode and the pixel electrode; and disposed between the pixel electrode and the common electrode. An active matrix type display device comprising: a first electro-optic element that displays the image according to the voltage or the current; and a second electro-optic element that displays an image different from the image,
The substrate includes a predetermined conductive region on a surface near the periphery,
The second electro-optic element is disposed between the conductive region and the common electrode, and is different from the image according to a voltage applied or a current flowing between the conductive region and the common electrode. An active matrix display device characterized by displaying an image. The substrate receives an image signal representing the image, applies a voltage to the plurality of video signal lines in accordance with the image signal, and a scanning signal selectively drives the plurality of scanning signal lines. Including all or part of a peripheral circuit consisting of at least one of the line drive circuit and
2. The active matrix display device according to claim 1, wherein the substrate includes the conductive region in a vicinity of a substantially vertical direction with respect to a substrate surface from a predetermined region in which the peripheral circuit is formed.   Forming the image to be displayed on the second electro-optic element by partially blocking at least one of the light to the second electro-optic element and the light from the second electro-optic element The active matrix display device according to claim 1, further comprising a light-shielding portion.   4. The active matrix display device according to claim 3, wherein the light shielding portion is opened in a shape corresponding to the image to be displayed. The second electro-optical element is a liquid crystal;
The active matrix display device according to claim 1, wherein the conductive region is an electrode for reflective display.   The active matrix display device according to claim 5, wherein the first electro-optical element is the same liquid crystal layer as the second electro-optical element.   The active matrix display device according to claim 1, wherein the conductive area has a shape corresponding to the image to be displayed. The substrate includes a conductive light-shielding region in the vicinity of a direction substantially perpendicular to the substrate surface from a predetermined region where the peripheral circuit is formed,
3. The active matrix according to claim 1, wherein the conductive region is formed so as to electrically separate a predetermined portion of the light shielding region from a portion other than the predetermined portion of the light shielding region. Type display device.   The portion excluding the predetermined portion of the light shielding region is electrically connected to the common electrode so that no voltage is applied to the common electrode or no current flows. 9. An active matrix display device according to 8.

Images