Patent Publication Number: US-2018039146-A1

Title: Active matrix substrate, and display device including same

Description:
TECHNICAL FIELD 
     The present invention relates to an active matrix substrate and a display device including the same. 
     BACKGROUND ART 
     Patent Document 1 described below discloses a display panel in which two pixel regions each of which includes a group of pixels defined by a plurality of gate lines and a plurality of data lines are arrayed in a direction in which the gate lines extend. The data lines in each pixel region are connected to one another in a frame region in the vicinity of one-side ends of the data lines. Further, in frame regions on the right and left sides of the display panel, gate drivers for the respective pixel regions are arranged. 
     PRIOR ART DOCUMENT 
     Patent Document 
     Patent Document 1: U.S. Pat. No. 8,659,583 
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     In a case of a display panel in which a plurality of pixel regions are arrayed along the gate lines, if driving circuits for driving gate lines in each pixel region are arranged in frame regions on the right and left sides of the display panel as is the case with Patent Document 1, the frame regions on the right and left sides of the display panel cannot be narrowed. 
     It is an object of the present invention to provide a technique for narrowing a frame region in an active matrix substrate that includes a display region in which a plurality of pixel regions are arrayed along gate lines, the pixel regions including pixel groups independent from each other, respectively. 
     Means to Solve the Problem 
     An active matrix substrate according to the present invention includes: a display region in which a plurality of pixel regions each of which includes data lines and gate lines are arrayed along a direction in which the gate lines extend; a terminal part provided outside the display region, in a first frame region in vicinity of one-side ends of the data lines, the terminal part supplying a data signal; and driving circuits provided in each of the pixel regions, for switching the gate lines in the pixel regions to a selected state or a non-selected state. In the active matrix substrate, the data lines in at least one pixel region among the plurality of pixel regions are connected with the terminal part, and the data lines in another pixel region are connected with the data lines in the one pixel region. 
     Effect of the Invention 
     With the configuration of the present invention, it is possible to narrow a frame region in an active matrix substrate that includes a display region in which a plurality of pixel regions are arrayed along gate lines, the pixel regions including pixel groups independent from each other, respectively. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  illustrates a schematic configuration of a liquid crystal display device according to Embodiment 1. 
         FIG. 2  is a schematic diagram illustrating an exemplary arrangement of source lines on the active matrix substrate illustrated in  FIG. 1 . 
         FIG. 3  is a schematic diagram illustrating a schematic configuration of the active matrix substrate in which the illustration of the source lines shown in  FIG. 2  is omitted. 
         FIG. 4  illustrates an equivalent circuit of the gate driver illustrated in  FIG. 3 . 
         FIG. 5A  is a schematic diagram illustrating an arrangement layout of the gate drivers illustrated in  FIG. 4 . 
         FIG. 5B  is a schematic diagram illustrating an arrangement layout of the gate drivers illustrated in  FIG. 4 . 
         FIG. 6  illustrates a timing chart when the gate driver illustrated in  FIG. 4  drives the gate lines. 
         FIG. 7  illustrates a timing chart of a data signal writing operation in Embodiment 1. 
         FIG. 8  illustrates a comparative example for the an active matrix substrate in Embodiment 1. 
         FIG. 9  is a schematic diagram illustrating an exemplary arrangement of source lines in an active matrix substrate in Embodiment 2. 
         FIG. 10A  is an enlarged schematic diagram illustrating a connection part in the frame region illustrated in  FIG. 9  where the source line portions and the source lines are connected. 
         FIG. 10B  is a cross-sectional view taken along line I-I in  FIG. 10  A, at the connection part where the source line and the routing line portion are connected with a connection line. 
         FIG. 11  illustrates a timing chart of a data signal writing operation in Embodiment 2. 
         FIG. 12  is a schematic diagram illustrating an exemplary arrangement of source lines in an active matrix substrate in Embodiment 3. 
         FIG. 13  illustrates a timing chart of a data signal writing operation in Embodiment 3. 
         FIG. 14  is a schematic diagram illustrating exemplary connection of source lines on an active matrix substrate in Embodiment 4. 
         FIG. 15  illustrates a timing chart of a data signal writing operation in Embodiment 4. 
         FIG. 16A  is an enlarged schematic diagram of source lines in a broken line frame P illustrated in  FIG. 14 . 
         FIG. 16B  is a cross-sectional view illustrating the source lines illustrated in  FIG. 16A , taken along line II-II. 
         FIG. 16C  is a cross-sectional view illustrating the source lines illustrated in  FIG. 16A , taken along line II-II. 
         FIG. 17A  is an enlarged schematic diagram illustrating a connection part in the frame region where the source line portions and the source lines are connected in Embodiment 5. 
         FIG. 17B  is a cross-sectional view of the connection part illustrated in  FIG. 17A , taken along line III-III. 
         FIG. 18  is a schematic diagram illustrating an active matrix substrate in Embodiment 6. 
         FIG. 19  illustrates a timing chart of a data signal writing operation in Embodiment 6. 
         FIG. 20  is a schematic diagram illustrating a schematic configuration of an active matrix substrate in Embodiment 7. 
         FIG. 21  illustrates an equivalent circuit of the gate driver illustrated in Embodiment 7. 
         FIG. 22A  is a schematic diagram illustrating an arrangement layout of the gate drivers illustrated in  FIG. 21 . 
         FIG. 22B  is a schematic diagram illustrating an arrangement layout of the gate drivers illustrated in  FIG. 21 . 
         FIG. 22C  is a schematic diagram illustrating an arrangement layout of the gate drivers illustrated in  FIG. 21 . 
         FIG. 22D  is a schematic diagram illustrating an arrangement layout of the gate drivers illustrated in  FIG. 21 . 
         FIG. 22E  is a schematic diagram illustrating an arrangement layout of the gate drivers illustrated in  FIG. 21 . 
         FIG. 23  illustrates a timing chart when the gate driver illustrated in  FIG. 21  drives a part of the gate lines. 
         FIG. 24A  is a timing chart of a data signal writing operation with respect to the first frame in Embodiment 7. 
         FIG. 24B  is a timing chart of a data signal writing operation in each frame period with respect to the second to sixtieth frames in Embodiment 7. 
         FIG. 25  is a schematic configuration of an active matrix substrate in Embodiment 8. 
         FIG. 26  is a schematic diagram illustrating an exemplary connection of source lines on an active matrix substrate in a modification example (1). 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     An active matrix substrate according to one embodiment of the present invention includes: a display region in which a plurality of pixel regions each of which includes data lines and gate lines are arrayed along a direction in which the gate lines extend; a terminal part provided outside the display region, in a first frame region in vicinity of one-side ends of the data lines, the terminal part supplying a data signal; and driving circuits provided in each of the pixel regions, for switching the gate lines in the pixel regions to a selected state or a non-selected state. In the active matrix substrate, the data lines in at least one pixel region among the plurality of pixel regions are connected with the terminal part, and the data lines in another pixel region are connected with the data lines in the one pixel region (the first configuration). 
     According to the first configuration, the active matrix substrate includes a display region in which a plurality of pixel regions are arrayed along a direction in which the gate lines extend. The active matrix substrate includes a terminal part in a first frame region for supplying a data signal to the data lines. Further, the active matrix substrate includes driving circuits provided in each of the pixel regions, for switching the gate lines in the pixel regions to a selected state or a non-selected state. The data lines in at least one pixel region are connected with the terminal part, and the data lines in another pixel region are connected with the data lines in the one pixel region. 
     In the first configuration, driving circuits are provided in each pixel region, which narrow the frame region in the vicinity of ends of the gate lines. Further, as the driving circuits are provided in each pixel region, a display region in which three or more pixel regions are arrayed along the gate line extending direction can be formed on the active matrix substrate. Further, the number of data lines connected with the terminal part is smaller than the total number of the data lines in all of the pixel regions. In other words, the number of data lines routed from the terminal part to the first frame region can be reduced, which makes it possible to narrow the first frame region, as compared with a case where all of the data lines are routed from the terminal part to the first frame region. 
     The second configuration may be the first configuration further characterized as follows: the data lines in the one pixel region and the data lines in the another pixel region are connected with each other in the first frame region. 
     With the second configuration, the data lines in the one pixel region can be connected with the data lines in the another pixel region in the first frame region. This makes it possible to narrow the first frame region, as compared with a case where all of the data lines are connected with the terminal part. 
     The third configuration may be the second configuration that further includes a switching part that selectively switches the data lines in the one pixel region for inputting the data signal, among the data lines in the one pixel region and the another pixel region. 
     With the third configuration, the data lines in the one pixel region for inputting a data signal can be selectively switched, whereby the electric power consumption when data signals are input can be reduced. 
     The fourth configuration may be the second or third configuration further characterized as follows: the active matrix substrate has a laminate structure that includes a first metal layer, and a second metal layer that is different from the first metal layer; the gate lines are formed in the first metal layer; the data lines are formed in the second metal layer; and the active matrix substrate further includes connection lines formed in the first metal layer or the second metal layer, the connection lines connecting, among the data lines of the another pixel region, the data lines that when extended intersect with the data lines of the one pixel region in the first frame region, and the data lines of the one pixel region. 
     With the fourth configuration, the data lines in the one pixel region and the data lines in the another pixel region can be connected, without intersecting with each other, by the connection lines. 
     The fifth configuration may be the second or third configuration further characterized as follows: the active matrix substrate has a laminate structure that includes a first metal layer, and a second metal layer that is different from the first metal layer; the gate lines are formed in the first metal layer; the data lines in the another pixel region are formed in the second metal layer; the data lines in the one pixel region have portions arranged in the one pixel region, which are formed in the second metal layer, and portions arranged in the first frame region, which are formed in the first metal layer; and the active matrix substrate further includes connection lines formed in the second metal layer, the connection lines connecting the data lines in the another pixel region and the data lines in the one pixel region. 
     With the fifth configuration, the data lines in the one pixel region and the data lines in the another pixel region can be connected, without intersecting with each other, by the connection lines. 
     The sixth configuration may be the second configuration further characterized as follows: the active matrix substrate has a laminate structure that includes a first metal layer, a second metal layer that is different from the first metal layer, and a third metal layer that is different from the first and second metal layers; the gate lines are formed in the first metal layer; the data lines in the another pixel region are formed in the second metal layer; the data lines in the one pixel region have portions arranged in the one pixel region, which are formed in the second metal layer, and portions arranged in the first frame region, which are formed in the first metal layer or the second metal layer; and the active matrix substrate further includes connection lines formed in the third metal layer, the connection lines connecting the data lines in the one pixel region and the data lines in the another pixel region. 
     With the sixth configuration, the data lines in the one pixel region and the data lines in the another pixel region can be connected, without intersecting with each other, by the connection lines. Besides, since portions of the data lines in the another pixel region arranged in the first frame region are formed in one of the first metal layer and the second metal layer, the interval of the data lines arranged in the first frame region can be narrowed, as compared with a case where the data lines are formed in the same metal layer. As a result, the first frame region can be further narrowed. 
     The seventh configuration may be the first configuration further characterized as follows: the data lines in the another pixel region are formed with the data lines in the one pixel region that are extended to the another pixel region while passing through a second frame region that is on an opposite side to the first frame region. 
     According to the seventh configuration, the data lines in the one pixel region double as the data lines in the another pixel region. Only the same number of data lines as in the one pixel region are therefore required to be arranged in the first frame region, which makes it possible to narrow the first frame region. 
     The eighth configuration may be the first configuration further characterized in that the data lines of the one pixel region and the data lines of the another pixel region are connected with each other in the display region. 
     According to the eighth configuration, the data lines of the one pixel region are connected with the data lines of the another pixel region in the display region. This makes it possible to narrow the first frame region, as compared with a case where all of the data lines are connected with the terminal part. 
     The ninth configuration may be any one of the first to seventh configurations further characterized in that a frame frequency for writing the data signal to a part of pixels in at least one pixel region among the pixel regions is lower than a frame frequency for writing the data signal to other pixels in the pixel region. 
     With the ninth configuration, it is possible to cause a part of pixels to display a still image, and cause other pixels to display a moving image, thereby reducing the electric power consumption when data signals are written. 
     The tenth configuration may be any one of the first to ninth configuration further characterized in that the display region has a non-rectangular shape. 
     A display device according to one embodiment of the present invention includes the active matrix substrate having any one of the first to tenth configurations, and a counter substrate including color filters provided at positions respectively corresponding to the pixels on the active matrix substrate (the eleventh configuration). 
     The twelfth configuration may be the eleventh configuration further characterized in that the color filters include color filters of R (red), G (green), and B (blue), and the color filters of R (red), G (green), and B (blue) are arrayed in an order of R (red), G (green), and B (blue) along a direction in which the data lines extend on the active matrix substrate. 
     With the twelfth configuration, the number of data lines can be decreased, as compared with a case where the pixels corresponding to the color filters of R (red), G (green), and B (blue) are arrayed in an order of R (red), G (green), and B (blue) along a direction in which the gate lines extend. As a result, the number of data lines routed from the terminal part to the first frame region can be reduced, whereby the first frame region can be further narrowed. 
     The following describes embodiments of the present invention in detail, while referring to the drawings. Identical or equivalent parts in the drawings are denoted by the same reference numerals, and the descriptions of the same are not repeated. 
     Embodiment 1 
     (Configuration of Liquid Crystal Display Device) 
       FIG. 1  is a top view illustrating a schematic configuration of a liquid crystal display device according to the present embodiment. The liquid crystal display device  1  includes a display panel  2 , a source driver  3 , a display control circuit  4 , and a power source  5 . The display panel  2  includes an active matrix substrate  20   a , a counter substrate  20   b , and a liquid crystal layer (not shown) interposed between these substrates. Though the illustration is omitted in  FIG. 1 , a pair of polarizing plates are provided so that the active matrix substrate  20   a  and the counter substrate  20   b  are interposed therebetween. On the counter substrate  20   b , there are formed a black matrix (BM), color filters of three colors, which are red (R), green (G), and blue (B), and a common electrode (all are not shown). 
     As illustrated in  FIG. 1 , the active matrix substrate  20   a  is electrically connected with the source driver  3  formed on a flexible substrate. The display control circuit  4  is electrically connected with the display panel  2 , the source driver  3 , and the power source  5 . The display control circuit  4  outputs control signals to the source driver  3 , and driving circuits (referred to as gate drivers) provided on the active matrix substrate  20   a , which are described below. The power source  5  is electrically connected with the display panel  2 , the source driver  3 , and the display control circuit  4 , and supplies a power source voltage signal to each of the same. 
     (Configuration of Active Matrix Substrate) 
       FIG. 2  is a schematic diagram illustrating a schematic configuration of the active matrix substrate  20   a . The active matrix substrate  20   a  includes a display region  200  in a rectangular shape in which areas  201 A and  201 B that include independent pixel groups, respectively, are arrayed along an X axis direction. 
     N gate lines  13  ( 13 ( 1 ) to  13 (N)) are formed in each of the area  201 A and the area  201 B, and are driven independently by areas. 
     In the area  201 A, M/2 (M: even integer) source lines (data lines)  15   a  ( 15 ( 1 ) to  15 (M/2) are formed. Each data line  15   a  in the area  201 A has the following configuration: one-side ends thereof is connected with a terminal part  12   s , and is extended from the terminal part  12   s , in a direction approximately vertical to the gate lines  13 , over a frame region R 1  outside the display region  200 , on one of sides parallel to the gate lines  13 , and the area  201 A. 
     In the area  201 B, M/2 source lines  15   b  ( 15 ( 1 ) to  15 (M/2) are formed. Each data line  15   b  in the area  201 B has the following configuration: one-side end thereof is connected with the source line  15   a  of the area  201 A, at the frame region R 1 , is extended from the connection position in a direction approximately parallel with the gate lines  13  to a predetermined position in the frame region R 1 , and is extended from the predetermined position in the direction approximately vertical to the gate lines  13  in the area  201 B. Hereinafter the source lines in the area  201 A and those in the area  201 B are referred to as the source lines  15  when they are not distinguished from each other. 
     In other words, in this example, M source lines  15  in total are provided in the areas  201 A and  201 B in the active matrix substrate  20   a.    
     Further, in the active matrix substrate  20   a , the terminal part  12   s  is provided in the frame region R 1 . The terminal part  12   s  receives data signals supplied from the source driver  3 . 
     In the present embodiment, the source lines  15   a  in one area  201 A are connected to the terminal part  12   s , and the source lines  15   b  in the other area  201 B are connected, in the frame region R 1 , with the source lines  15   a  of the area  201 A. The number of the source lines  15  routed from the terminal part  12   s  to the frame region R 1  is therefore only M/2. The width L in the extending direction of the source line  15  in the frame region R 1  is required only to have a length for arranging the M/2 source lines  15  of the area  201 B in parallel. 
     In this example, the source lines  15   a  of the area  201 A are connected with the terminal part  12   s , but the configuration may such that the source lines  15   b  of the area  201 B and the terminal part  12   s  are connected, and the source lines  15   a  of the area  201 A are connected, in the frame region R 1 , with the source lines  15   b  of the area  201 B. 
     Each pixel in the areas  201 A and  201 B corresponds to any one of the colors of R, G, and B of the color filters. The color filters of the respective colors of R, G, and B in the counter substrate  20   b  are arrayed in the order of R, G, and B along the direction in which the gate lines  13  extend. 
     Further, in the vicinity of the intersection of one gate line  13  and one source line  15  in each pixel, a pixel thin film transistor (TFT)  17  (see  FIGS. 5A, 5B  and the like) connected to the gate line  13  and the source line  15  is arranged. At each pixel, a pixel electrode (not shown) is arranged, and the pixel electrode is connected to the drain terminal of the pixel TFT. 
     In each of the areas  201 A and  201 B, a plurality of gate drivers  11  for switching the gate lines  13  in the area into a selected state or a non-selected state are provided.  FIG. 3  is a schematic diagram illustrating a schematic configuration of the active matrix substrate  20   a  in which the illustration of the source lines  15  and the terminal part  12   s  is omitted. As illustrated in  FIG. 3 , in the frame region R 1 , a terminal part  12   g  is arranged. The terminal part  12   g  is connected with the display control circuit  4  (see  FIG. 1 ), and supplies control signals supplied from the display control circuit  4  via control lines  16  to each gate driver  11 . 
     Next, the following description describes the gate driver  11 .  FIG. 4  illustrates an equivalent circuit of one gate driver  11  in the present embodiment. In the example in  FIG. 4 , an equivalent circuit of the gate driver  11 ( n ) that drives the gate line  13 ( n ) (n: integer, 1≦n≦N) is illustrated. 
     As illustrated in  FIG. 4 , the gate driver  11 ( n ) has TFTs indicated by alphabetic characters A to L (hereinafter referred to as TFTs-A to -L), and a capacitor Cbst. 
     In  FIG. 4 , an internal line to which a source terminal of TFT-B, drain terminals of TFT-A, TFT-C, and TFT-K, a gate terminal of TFT-F, and one of electrodes of the capacitor Cbst are connected is referred to as “netA”. Further, an internal line to which a source terminal of TFT-G, drain terminals of TFT-H, TFT-I, and TFT-J, and a gate terminal of TFT-C are connected is referred to as “netB”. 
     Since the gate drivers  11  are provided in the area  201 A or the area  201 B, netA and netB have parasitic capacitances Cpa and Cpb, respectively, between the same and the source lines  15  (see  FIG. 2 ) or other elements provided in the pixels. 
     The drain terminal of TFT-A is connected with netA, a reset signal CLR is supplied to the gate terminal, and the power source voltage signal VSS is supplied to the source terminal. The TFT-A pulls down netA(n) to a low (L) level (VSS) according to the potential of the reset signal CLR. 
     Regarding TFT-B, netA in the gate driver  11 ( n −2) that drives the gate line  13 ( n −2) (hereinafter referred to as “netA(n−2)”) is connected to the gate terminal thereof, the drain terminal thereof is connected with the gate line  13 ( n −1), and the source terminal thereof is connected with netA in the gate driver  11 ( n ) (hereinafter referred to as “netA(n)”). 
     To the gate terminal and the drain terminal of TFT-B in the gate driver  11 ( 1 ) that drives the gate line  13 ( 1 ), a startpulse signal is supplied as a set signal S from the display control circuit  4  at a predetermined timing. 
     Regarding TFT-C, the gate terminal thereof is connected with netB(n), the drain terminal thereof is connected with netA(n), and to the source terminal thereof, a power source voltage signal VSS is supplied. 
     Regarding TFT-K, the gate terminal thereof is connected with the gate line  13 ( n +2), the drain terminal thereof is connected with netA(n), and to the source terminal thereof, the power source voltage signal VSS is supplied. 
     Regarding TFT-F, the gate terminal thereof is connected with netA(n), the source terminal thereof is connected to the gate line  13 ( n ), and to the drain terminal thereof, a clock signal CKA is supplied. It should be noted that TFT-F has to have a great channel width since it drives the gate line  13  on which a relatively heavy load is applied. In the equivalent circuit illustrated in  FIG. 5 , TFT-F is represented by one TFT, but TFT-F is formed with a plurality of TFTs connected in parallel. 
     Regarding the capacitor Cbst, one of electrodes thereof is connected with netA(n), and the other electrode thereof is connected with the gate line  13 ( n ). 
     Regarding TFT-E, the drain terminal thereof is connected with the gate line  13 ( n ), the reset signal CLR is supplied to the gate terminal thereof, and a power source voltage signal VSS is supplied to the source terminal thereof. 
     Regarding TFT-D, the drain terminal thereof is connected with the gate line  13 ( n ), a clock signal CKB is supplied to the gate terminal, and the power source voltage signal VSS is supplied to the source terminal. 
     Regarding TFT-L, the drain terminal thereof is connected with the gate line  13 ( n ), the gate terminal thereof is connected with the gate line  13 ( n +2), and the power source voltage signal VSS is supplied to the source terminal. 
     Regarding TFT-G, the gate terminal thereof and the drain terminal thereof are connected, a clock signal CKD is supplied to the gate terminal and the drain terminal, and the source terminal is connected to netB(n). 
     Regarding TFT-H, the drain terminal thereof is connected to netB(n), a clock signal CKC is supplied to the gate terminal thereof, and the power source voltage signal VSS is supplied to the source terminal thereof. 
     Regarding TFT-I, the drain terminal thereof is connected with netB(n), the reset signal CLR is supplied to the gate terminal thereof, and the power source voltage signal VSS is supplied to the source terminal thereof. 
     Regarding TFT-J, the drain terminal thereof is connected with netB(n), the gate terminal thereof is connected with the gate line  13 ( n −1), and the power source voltage signal VSS is supplied to the source terminal thereof. To the gate terminal of TFT-J in the gate driver  11 ( 1 ), the startpulse signal is supplied as a set signal S from the display control circuit  4 . 
     Next, an exemplary arrangement of respective elements of the gate driver  11  is described below.  FIGS. 5A and 5B  are schematic diagrams that illustrate arrangement layouts of respective elements of the gate driver  11 ( n ), and the gate driver  11 ( n −2) that drives the gate line  13 ( n −2), arranged in, for example, the area  201 A.  FIGS. 5A and 5B  are assumed to be continuous to each other, with the column P 1  illustrated in  FIG. 5A  and the column P 2  illustrated in  FIG. 5B  being adjacent to each other. 
     In these diagrams, the illustration of the arrangement layout of the gate driver  11 ( n −1) and the gate driver  11 ( n +1) is omitted; these gate drivers are arranged in columns different from those where the gate driver  11 ( n ) and the gate driver  11 ( n −2) are arranged, in the same manner as that where the gate driver  11 ( n ) and the gate driver  11 ( n −2) are arranged. Here, thought the illustration is omitted, the elements of the gate driver  11  are arranged in the area  201 B in the same manner as the manner in the area  201 A. 
     As illustrated in  FIGS. 5A and 5B , TFTs-A to -L, the capacitor Cbst, netA(n−2), and netB(n−2) of the gate driver  11 ( n −2) are arranged between the gate line  13 ( n −2) and the gate line  13 ( n −1). TFTs-A to -L, the capacitor Cbst, netA(n), and netB(n) of the gate driver  11 ( n ) are arranged between the gate line  13 ( n ) and the gate line  13 ( n +1). 
     As illustrated in  FIGS. 5A and 5B , the control lines  16  supplying the clock signals CKA to CKD, the reset signal CLR, and the power source voltage signal VSS are led out of the terminal part  12   g  (see  FIG. 3 ), and are connected with the TFTs to which the control signals supplied through the control lines  16  are input. 
     Next, the following description describes operations of the gate driver  11 .  FIG. 6  illustrates exemplary waveforms of the clock signals CKA to CKD, and a timing chart when the gate driver  11 ( n ) drives the gate line  13 ( n ). 
     As illustrated in  FIG. 6 , the clock signals CKA, CKB, CKC, and CKD are control signals having potentials that change to the high (H) level or to the low (L) level every two horizontal scanning periods ( 2 H). 
     The phases of the clock signals CKA and CKB are opposite, and so are the phases of the clock signals CKC and CKD. Further, the phases of the clock signals CKA and CKC are shifted by ¼ cycle, and so are the phases of the clock signals CKC and CKB. Still further, the phases of the clock signals CKB and CKD are shifted by ¼ cycle, and so are the phases of the clock signals CKD and CKA. 
     As illustrated in  FIGS. 5A and 5B , the clock signals CKB, CKA, CKD, and CKC are supplied to the TFTs-D, -F, -G, and -H of the gate driver  11 ( n ), respectively, whereas the clock signals CKA, CKB, CKC, and CKD are supplied to the TFTs-D, -F, -G, and -H of the gate driver  11 ( n −2), respectively. In other words, the clock signals having phases opposite to each other are supplied to the gate driver  11 ( n ) and the gate driver  11 ( n −2). 
     Though the illustration of the reset signal CLR is omitted in  FIG. 6 , the reset signal CLR is a control signal that is maintained at the H level during a certain period every one perpendicular scanning period. When the reset signal CLR is input to the gate driver  11 , potentials of netA and netB in the gate driver  11 , and the gate line  13  driven by the gate driver  11 , fall to the L level. The following description describes the operations of the gate driver  11 ( n ), while referring to  FIGS. 4 and 6 . 
     At a timing of time t 1  in  FIG. 6 , the gate line  13 ( n −1) is switched to the selected state, the voltage at the H level of the gate line  13 ( n −1) is input as a set signal S to the drain terminal of TFT-B of the gate driver  11 ( n ). Further, the voltage of netA(n−2) is input to the gate terminal of TFT-B. The potential of netA(n−2) is at H level before time t 1 , and TFT-B is turned ON at time t 1 . TFT-B remains in the in the ON state until time  2  when the potential of netA(n−2) falls to the L level, and netA(n) is precharged to the potential at the H level of the gate line  13 ( n −1) from time t 1  to t 2 . 
     The gate terminal of TFT-F is turned ON since the voltage at the H level of netA(n) is input thereto. At time t 1 , TFT-D is turned ON since a voltage at the H level of the clock signal CKB is input to the gate terminal of TFT-D, and the voltage (VSS) at the L level is input to the gate line  13 ( n ). 
     Further, at time t 1 , the potential of the clock signal CKD is at the H level, and the potential of the clock signal CKC is at the L level. This causes TFT-G to be turned ON, and TFT-H to be turned OFF. The voltage at the H level of the gate line  13 ( n −1) is input as a set signal S to the gate terminal of TFT-J, whereby TFT-J is turned ON. NetB(n) is therefore maintained at the potential at the L level, and TFT-C is turned OFF. 
     At time t 2 , the potential of the clock signal CKA rises to the H level, a voltage at the H level of the clock signal CKA is input to the gate line  13 ( n ) via TFT-F. As the potential of the gate line  13 ( n ) rises, netA(n) is charged to a potential higher than the potential at the H level of the clock signal CKA by the capacitor Cbst connected between netA(n) and the gate line  13 ( n ). 
     At time t 2 , the potential of the gate line  13 ( n −1) is at the H level, TFT-J remains in the ON state. At time t 3 , the potential of the clock signal CKC rises to the H level, and remains at the H level until time t 4 . During this period, TFT-H is turned ON, and netB(n) is maintained at the potential at the L level. 
     Further, at time t 2 , the potential of the clock signal CKB shifts from the H level to the L level, and TFT-D is turned OFF. This causes the potential at the H level of the clock signal CKA (selection voltage) to be output to the gate line  13 ( n ) during a period from time t 2  to time t 4 , thereby causing the gate line  13 ( n ) to be switched to the selected state. 
     The gate driver  11 ( n +1) driving the gate line  13 ( n +1) operates in the same manner as the gate driver  11 ( n ), using the potential of the gate line  13 ( n ) as the set signal S, and the gate driver  11 ( n +2) driving the gate line  13 ( n +2) operates in the same manner as the gate driver  11 ( n ), using the potential of the gate line  13 ( n +1) as the set signal S. As a result, the gate line  13 ( n +1) is switched to the selected state at the timing of time t 3 , and the gate line  13 ( n +2) is switched to the selected state at the timing of time t 4 . 
     The potential of the clock signal CKB rises to the H level at time t 4 , whereby TFT-D is turned ON. Further, at time t 4 , the potential of the gate line  13 ( n +2) rises to the H level, whereby TFT-K and TFT-L are also turned ON. This causes a voltage at the L level to be input to the gate line  13 ( n ) via TFT-D and TFT-L, whereby the gate line  13 ( n ) is switched to the non-selected state. Further, a voltage at the L level is input to netA(n) via TFT-K. Here, since the potential of the clock signal CKC is at the H level and TFT-H is in the ON state, the potential of netB(n) is maintained at the L level. 
     Subsequently, at time t 5 , when the potential of the clock signal CKD rises to the H level and the potential of the clock signal CKC falls to the L level, TFT-H is turned OFF and TFT-G is turned ON. This causes netB(n) to be charged to a potential that is smaller by the threshold value voltage of TFT-G, with respect to the potential at the H level of the clock signal CKD. Here, since TFT-K and TFT-L are in the ON state and TFT-C is turned ON, netA(n) and the gate line  13 ( n ) are maintained at the potential at the L level. 
     After time t 6 , at a timing when the clock signal CKB has a potential at H level, the gate line  13 ( n ) is maintained at the potential at the L level via TFT-D. 
     Further, after time t 6 , at a timing when the clock signal CKD has a potential at H level, netB(n) is charged to the potential at the H level, while netA(n) maintains a potential at the L level via TFT-C. 
     Next, the following description describes an operation of writing data signals to the pixels in the areas  201 A and  201 B.  FIG. 7  is a timing chart when data signals are written in the areas  201 A and  201 B. Waveforms of the gate lines  13 ( 1 ) to  13 (N) in this diagram are waveforms during one horizontal scanning period ( 1 H) that is latter one of two horizontal scanning periods ( 2 H) when the gate lines  13  have a potential at the H level. In other words, the waveforms of the gate lines  13 ( n ) in  FIG. 7  are waveforms of the gate lines  13 ( n ) during one horizontal scanning period from time t 3  to time t 4  illustrated in  FIG. 6 . 
     After supplying the reset signal CLR to the terminal part  12   g , the display control circuit  4  supplies, to the terminal part  12   g , a startpulse signal SPa as a set signal S for the gate driver  11 ( 1 ) in the area  201 A, and supplies control signals (the clock signals CKA to CKD) to the terminal part  12   g . This causes the gate lines  13 ( 1 ) to  13 (N) in the area  201 A to be sequentially driven by the gate drivers  11  in the area  201 A. 
     The gate lines  13 ( 1 ) to  13 (N) in the area  201 A are sequentially driven, and the source driver  3  supplies data signals to be written in the pixels of the respective rows in the area  201 A, to the terminal part  12   s , at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( 1 ) to  13 (N) in the area  201 A. 
     This allows data signals Da( 1 , j), Da( 2 , j) . . . Da(N, j) to be supplied to the source lines  15   a ( j ) (j: integer, 1≦j≦M) in the area  201 A, respectively, from the terminal part  12   s . Further, to the source lines  15   b ( j ) in the area  201 B as well, the data signals Da( 1 , j), Da( 2 , j) . . . Da(N, j) are supplied, via the source lines  15   a ( j ), respectively. 
     As a result, the data signals Da( 1 , j), Da( 2 , j) . . . Da(N, j) are sequentially input to the pixel electrodes connected to the pixel TFTs connected with the source lines  15   a ( j ), at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( 1 ) to  13 (N) in the area  201 A, whereby data signals are written in all of the pixels in the area  201 A. Here, since all of the gate lines  13  in the area  201 B have potentials at the L level, data signals supplied to the source lines  15   b ( j ) are not written in the pixels in the area  201 B. 
     Subsequently, the display control circuit  4  supplies, to the terminal part  12   g , a startpulse signal SPb as a set signal S for the gate driver  11 ( 1 ) in the area  201 B, and at the same time, supplies control signals (the clock signals CKA to CKD) to the terminal part  12   g . This causes the gate lines  13   b ( 1 ) to  13   b (N) to be sequentially driven by the gate drivers  11  in the area  201 B. 
     The gate lines  13 ( 1 ) to  13 (N) in the area  201 B are sequentially driven, and the source driver  3  supplies data signals to be written in the pixels of the respective rows in the area  201 B, to the terminal part  12   s , at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( 1 ) to  13 (N) in the area  201 B. This causes data signals Db( 1 , j), Db( 2 , j) . . . Db(N, j) to be supplied from the terminal part  12   s  to the source lines  15   a ( j ). Further, the data signals Db( 1 , j), Db( 2 , j) . . . Db(N, j) are supplied via the source lines  15   a ( j ) to the source lines  15   b ( j ). 
     As a result, at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( 1 ) to  13 (N) in the area  201 B, data signals Db( 1 , j), Db( 2 , j) . . . Db(N, j) are input to the source lines  15   b ( j ), respectively, whereby data signals are written in all of the pixels in the area  201 B. Here, since the potentials of all of the gate lines  13  in the area  201 A are at the L level, the data signals supplied to the source lines  15   a ( j ) are not written in the pixels in the area  201 A. 
     In this way, by driving the gate lines  13  in the area  201 B after driving the gate lines  13  in the area  201 A, data signals can be written in all of the pixels of the areas  201 A and  201 B. 
     In the example described above, the startpulse signal SPb is supplied as the set signal S from the display control circuit  4  to the gate driver  11 ( 1 ) in the area  201 B, but the potential of the gate line  13 (N) in the area  201 A may be supplied in place of the startpulse signal SPb. 
     Here, the following description describes, as a comparative example, an active matrix substrate  50  in which the terminal part  12   s , the gate lines  13 , and the source lines  15  of the active matrix substrate  20   a  in the present embodiment are provisionally arranged as illustrated in  FIG. 8 . In frame regions R 2  and R 3  in the right and left parts of the active matrix substrate  50 , gate drivers  100  for driving the gate lines  13  in areas  201 A and  201 B are provided, respectively. In this case, the width L 11  in the gate line  13  extending direction of each of the frame regions R 2  and R 3  is required to be a width enough to arrange the gate driver  100 . On the other hand, in Embodiment 1 described above, the gate drivers  11  for driving the gate lines  13  in the areas  201 A and  201 B are arranged in the areas, respectively (see  FIGS. 2, 3 ). This allows the width in the gate line  13  extending direction of each of the right and left frame regions R 1  and R 2  in the active matrix substrate  20   a  to be narrower than the width of each of the frame regions R 1  and R 2  illustrated in  FIG. 8 . 
     Further, since M/2 source lines  15  are routed from the terminal part  12   s  to each of the areas  201 A and  201 B on the active matrix substrate  50  illustrated in  FIG. 8 , the frame region R 1  is required to have a width L for routing M source lines  15  from the terminal part  12   s . On the other hand, in Embodiment 1 described above, as illustrated in  FIG. 2 , the source lines  15   a  are routed from the terminal part  12   s  to the area  201 A, without being bent. The source lines  15   b  are, at one-side ends thereof, connected to portions  150   a  of the source lines  15   a  in the frame region R 1 , and are routed to the area  201 B. In Embodiment 1, therefore, the frame region R 1  is required only to have a width L for routing M/2 source lines  15   a  from the terminal part  12   s , and hence, the width of the frame region R 1  can be narrower than the width of the frame region R 1  illustrated in  FIG. 8 . 
     Embodiment 2 
     The display region  200  of the active matrix substrate  20   a  of the present embodiment is different from Embodiment 1 in the point that four pixel regions having independent pixel groups, respectively, are arrayed. The following description describes configurations thereof different from those in Embodiment 1. 
       FIG. 9  is a schematic diagram illustrating an exemplary arrangement of source lines on the active matrix substrate  20   a  in the present embodiment. As illustrated in  FIG. 9 , in the present embodiment, N gate lines  13  and M/4 source lines  15  ( 15   a ,  15   b ,  15   c ,  15   d ) are formed in each of four areas  201 A,  201 B,  201 C, and  201 D. In other words, the active matrix substrate  20   a  includes M source lines  15  in total, as is the case with Embodiment 1. Hereinafter, when the source lines in the respective areas are not distinguished, they are referred to as the “source lines  15 ” collectively. 
     Though the illustration is omitted in  FIG. 9 , gate drivers  11  for driving the gate lines  13  in each area are provided in the area, as is the case with Embodiment 1. Further, a terminal part  12   s  is provided in the frame region R 1 . 
     As illustrated in  FIG. 9 , source lines  15   a  in the area  201 A and source lines  15   d  in the area  201 D are routed separately from the terminal part  12   s . The source lines  15   a  and the source line  15   d  are arranged so as to be approximately horizontally symmetric with respect to the boundary between the area  201 B and the area  201 C. The source lines  15   b  in the area  201 B are connected with portions  150   a  of the source lines  15   a  arranged in the frame region R 1  through connection lines  131 . Further, the source lines  15   c  in the area  201 C are connected with portions  150   d  of the source lines  15   d  arranged in the frame region R 1  through connection lines  131 . 
       FIG. 10A  is an enlarged schematic diagram illustrating a connection part where the source lines  15   d  and the source lines  15   c  are connected through the connection lines  131 . As illustrated in  FIG. 10A , the portions  150   d  of the source lines  15   d  arranged in the frame region R 1  (hereinafter referred to as the source line portions  150   d ) are arranged approximately in parallel with one another, with a certain angle being formed between the source line portions  150   d  and the connection lines  131 . Each connection line  131  extends approximately linearly from an end of one of the source lines  15   c  arranged in the area  201 C to the source line portions  150   d  of the source line  15   d  corresponding to the source line  15   c.    
       FIG. 10B  is a cross-sectional view of the connection part illustrated in  FIG. 10A  where the source line  15   c  and the source line portion  150   d  are connected with the connection line  131 , the cross-section being taken along line I-I in  FIG. 10A . As illustrated in  FIG. 10B , the connection line  131  is formed on the first metal layer  1300  formed on the substrate  1000  composing the active matrix substrate  20   a . Though not illustrated in this drawing, the gate lines  13  are formed on the first metal layer  1300 . 
     In  FIG. 10B , an insulating film  1100  is provided to cover the connection line  131 , and a second metal layer  1500  is formed on the insulating film  1100 . On the second metal layer  1500 , the source line  15   c  and the source line portions  150   d  are formed. The source line  15   c  and the source line portion  150   d  are connected with the connection line  131  though contact holes CH provided in the insulating film  1100 . 
     In this way, the connection lines  131  are formed in the first metal layer  1300  that is different from the second metal layer  1500  in which the source line portions  150   d  and the source lines  15   c  are formed. This makes it possible to connect the source lines  15   d  and the source lines  15   c , without causing the source line portions  150   d  and the source lines  15   c  to intersect with one another. 
     With reference to the above-described example, the structure of connection between the source line  15   c  and the source line portion  150   d  is described in the foregoing description. The structure of connection between the source line  15   b  and the portion  150   a  of the source line  15   a  arranged in the frame region R 1  (hereinafter referred to as the source line portion  150   a ) is identical to the above-described structure. 
     Next, the following description describes a data signal writing operation in the present embodiment.  FIG. 11  illustrates a timing chart of a data signal writing operation in the present embodiment. As is the case with  FIG. 7  mentioned above, the waveforms of the gate lines  13 ( 1 ) to  13 (N) in this diagram are waveforms during one horizontal scanning period ( 1 H) that is latter one of two horizontal scanning periods ( 2 H) when the gate lines  13  have a potential at the H level. In other words, the waveforms of the gate lines  13 ( n ) in  FIG. 11  are waveforms of the gate lines  13 ( n ) during one horizontal scanning period from time t 3  to time t 4  illustrated in  FIG. 6 . 
     After supplying the reset signal CLR to the terminal part  12   g , the display control circuit  4  supplies, to the terminal part  12   g , startpulse signals SPa and SPc as set signals S for the gate drivers  11 ( 1 ) in the areas  201 A and area  201 C, and supplies control signals (the clock signals CKA to CKD) to the terminal part  12   g , and at the same time, supplies control signals (the clock signals CKA to CKD) to the terminal part  12   g.    
     This causes the gate lines  13 ( 1 ) to  13 (N) in the area  201 A and the gate lines  13 ( 1 ) to  13 (N) in the area  201 C to be sequentially driven at the same timings by the gate drivers  11  in the areas  201 A and  201 C. 
     The gate lines  13 ( 1 ) to  13 (N) in the area  201 A and the area  201 C are sequentially driven, and at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( 1 ) to  13 (N) in the area  201 A and the area  201 C, data signals Da (Da( 1 , j), Da( 2 , j) . . . Da(N, j)) to be written in the pixels of the respective rows in the area  201 A, and data signals Dc (Dc( 1 , j), Dc( 2 , j) . . . Dc(N, j)) to be written in the pixels of the respective rows in the area  201 C (j: integer, 1≦j≦M/4), are supplied from the source driver  3  to the terminal part  12   s.    
     This allows the data signals Da( 1 , j), Da( 2 , j) . . . Da(N, j) to be sequentially input to the source lines  15   a ( j ) at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( 1 ) to  13 (N) in the area  201 A, whereby the data signals are written in all of the pixels in the area  201 A. Further, this allows the data signals Dc( 1 , j), Dc( 2 , j) . . . Dc(N, j) to be sequentially input through the connection lines  131  to the source lines  15   c ( j ) at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( 1 ) to  13 (N) in the area  201 C, whereby the data signals are written in all of the pixels in the area  201 C. Here, data signals are supplied to the source lines  15   b ( j ) and  15   d ( j ) as well, but since the potentials of all of the gate lines  13  in the areas  201 B and  201 D are at the L level, the data signals are not written in the pixels in the areas  201 B and  201 D. 
     Next, the display control circuit  4  supplies, to the terminal part  12   g , startpulse signals SPb and SPd as set signals S for the gate drivers  11 ( 1 ) in the areas  201 B and  201 D, and supplies control signals (the clock signals CKA to CKD) to the terminal part  12   g.    
     This causes the gate lines  13   b ( 1 ) to  13   b (N) in the area  201 B and the area  201 D to be sequentially driven by the gate drivers  11  in the areas  201 B and  201 D at the same timings. 
     The gate lines  13  in the areas  201 B and the area  201 D are sequentially driven, and at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13  in the areas  201 B and the area  201 D, data signals Db (Db( 1 , j), Db( 2 , j) . . . Db(N, j)) to be written in the pixels of the respective rows in the area  201 B, and data signals Dd (Dd( 1 , j), Dd( 2 , j) . . . Dd(N, j)) to be written in the pixels of the respective columns in the area  201 D, are supplied from the source driver  3  to the terminal part  12   s.    
     This allows the data signals Db( 1 , j), Db( 2 , j) . . . Db(N, j) to be sequentially input through the connection lines  131  to the source lines  15   b ( j ) at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( 1 ) to  13 (N) in the area  201 B, whereby the data signals are written in all of the pixels in the area  201 B. Further, this allows the data signals Dd( 1 , j), Dd( 2 , j) . . . Dd(N, j) to be sequentially input to the source lines  15   d ( j ) at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( 1 ) to  13 (N) in the area  201 D, whereby the data signals are written in all of the pixels in the area  201 D. Here, data signals are supplied to the source lines  15   a ( j ) and  15   c ( j ) as well, but since the potentials of all of the gate lines  13  in the areas  201 A and  201 C are at the L level, the data signals are not written in the pixels in the areas  201 A and  201 C. 
     In Embodiment 2 described above, first, the gate lines  13  in the areas  201 A and  201 C are driven, and data signals are written in the pixels in these areas. Then, after the writing of data signals in the areas  201 A and  201 C ends, the gate lines  13  in the areas  201 B and  201 D are driven, and data signals are written to the pixels in these areas. In this way, data signals can be written in all of the pixels in the active matrix substrate  20   a.    
     Further, in Embodiment 2, M/2 source lines  15  in total, which are M/4 source lines  15   a  in the area  201 A and M/4 source lines  15   d  in the area  201 D, are routed from the terminal part  12   s ; among these, the source lines  15   a  and the source lines  15   d  are routed approximately horizontally symmetrically with respect to the boundary between the areas  201 B and  201 C interposed therebetween. The width L of the frame region R 1 , therefore, is required only to be a width enough for routing M/4 source lines  15  from the terminal part  12   s . As compared with the case where the source lines  15  in all of the areas are routed from the terminal part  12   s , therefore, the width L of the frame region R 1  can be reduced. 
     The foregoing description of Embodiment 2 refers to an exemplary case where all of the source lines  15   b  and  15   c  are connected through the connection lines  131  to the source lines  15   a  and  15   d , respectively, but the configuration may be as follows. For example, among the source lines  15   b  and  15   c  arranged in the areas  201 B and  201 C, the source lines  15   b  and  15   c  that when extended intersect with the source lines  15   b  and  15   c  are connected through the connection lines  131  with the source lines  15   a  and  15   d , and the other source lines  15   b  and  15   c  are directly connected with the corresponding source lines  15   a  and  15   d.    
     Further, the foregoing description of Embodiment 2 refers to an exemplary case where the connection lines  131  are formed in the first metal layer  1300 , but the connection lines  131  may be formed in the second metal layer  1500 . In this case, however, the source line portions  150   a  and  150   d  are formed in the first metal layer  1300 , and the source line portions  150   a  and  150   d  and the source lines  15   a  and  15   d  are connected through contacts. Then, the source lines  15   b  and  15   c  may be connected through the connection lines  131  with the source line portions  150   a  and  150   d.    
     Embodiment 3 
     The present embodiment is different from Embodiment 2 described above in the following point: the source lines  15   a  in the area  201 A and the source lines  15   b  in the area  201 B are connected through switching elements, and the source lines  15   c  in the area  201 C and the source lines  15   d  in the area  201 D are connected through switching elements. 
       FIG. 12  is a schematic diagram illustrating exemplary connection of the source lines  15   a  to  15   d  in the areas  201 A to  201 D in the present embodiment. In this diagram, the illustration of the gate drivers  11  and the terminal part  12   g  is omitted. The following description describes configurations different from those in Embodiment 2. 
     As illustrated in  FIG. 12 , the source lines  15   a  and the source lines  15   c  are connected with switching elements SW 1  in the frame region R 1 , and the source lines  15   b  and the source lines  15   d  are connected with switching elements SW 2  in the frame region R 1 . 
     The source lines  15   a  are connected through the switching elements SW 1  with the terminal part  12   s . The source lines  15   b  are connected, through the switching elements SW 2 , with the source line portions  150   a  connected with the terminal part  12   s . Further, the source lines  15   d  are connected through the switching elements SW 2  with the terminal part  12   s . The source lines  15   c  are connected through the switching elements SW 1  with the source line portions  150   d  connected with the terminal part  12   s.    
     The source lines  15   a  are conductive with the terminal part  12   s  when the switching elements SW 1  are in the ON state. The source lines  15   d  are conductive with the terminal part  12   s  when the switching elements SW 2  are in the ON state. The source lines  15   b  are conductive with the terminal part  12   s  through the source line portions  150   a  when the switching elements SW 2  are in the ON state. The source lines  15   c  are conductive with the terminal part  12   s  through the source line portions  150   d  when the switching elements SW 1  are in the ON state. 
     The switching elements SW 1  and SW 2  are connected with the display control circuit  4  (see  FIG. 2 ). To the gate terminals of the switching elements SW 1  and SW 2 , a voltage at the H level or the L level is supplied from the display control circuit  4   
       FIG. 13  illustrates a timing chart of a data signal writing operation in the present embodiment. The present embodiment is identical to Embodiment 2 regarding the point that data signal writing is performed with respect to the areas  201 B and  201 D after data signal writing with respect to the areas  201 A and  201 C, but the present embodiment is different from Embodiment 2 regarding the following point. As is the case with  FIG. 7  mentioned above, the waveforms of the gate lines  13 ( 1 ) to  13 (N) in this diagram are waveforms during one horizontal scanning period ( 1 H) that is latter one of two horizontal scanning periods ( 2 H) when the gate lines  13  have a potential at the H level. In other words, the waveforms of the gate lines  13 ( n ) in  FIG. 13  are waveforms of the gate lines  13 ( n ) during one horizontal scanning period from time t 3  to time t 4  illustrated in  FIG. 6 . 
     As illustrated in  FIG. 13 , at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13  in the areas  201 A and  201 C, the display control circuit  4  input data signals for the areas  201 A and  201 C to the terminal part  12   s , and at the same time, supplies a voltage at the H level to the gate terminals of the switching elements SW 1 , while supplying a voltage at the L level to the gate terminals of the switching elements SW 2 . This causes the switching elements SW 1  to be turned ON, and causes the switching elements SW 2  to be turned OFF. As a result, the source lines  15   a ( j ) become conductive with the terminal part  12   s . Further, the source lines  15   c ( j ) become conductive with the terminal part  12   s  through the source line portions  150   d . This causes data signals for the areas  201 A and  201 C to be input to the source lines  15   a ( j ) and the source lines  15   c ( j ), respectively, from the terminal part  12   s . During this period, since the source lines  15   b ( j ) and  15   d ( j ) in the areas  201 B and  201 D are not conductive, data signals for the areas  201 A and  201 C are not input to the source lines  15   a ( j ) and  15   c ( j ), respectively. 
     After the writing of data signals to the areas  201 A and  201 C ends, the display control circuit  4  inputs data signals for the areas  201 B and  201 D to the terminal part  12   s , and at the same time, supplies a voltage at the L level to the gate terminals of the switching elements SW 1 , while supplying a voltage at the H level to the gate terminals of the switching elements SW 2 . This causes the switching elements SW 1  to be turned OFF, and causes the switching elements SW 2  to be turned ON, whereby the source lines  15   b ( j ) become conductive with the terminal part  12   s  through the source line portions  150   a . Further, the source lines  15   d ( j ) become conductive with the terminal part  12   s . As a result, data signals for the area  201 B are input to the source lines  15   b ( j ) from the terminal part  12   s , and data signals for the area  201 D are input to the source lines  15   d ( j ) from the terminal part  12   s . During this period, since the source lines  15   a ( j ) and  15   c ( j ) are not conductive, data signals for the areas  201 A and  201 C are not input to the source lines  15   a ( j ) and  15   c ( j ). 
     In Embodiment 3, by controlling ON/OFF of the switching elements SW 1  and SW 2 , only the source lines in an area to which data signals are to be written are caused to be conductive with the terminal part  12   s , so that the data signals are not input to the source lines in the other areas. Charging/discharging of the source lines  15  in areas where the writing of data signals is not performed is therefore made unnecessary, which makes it possible to reduce the power consumption for inputting data signals to the source lines  15 . 
     Embodiment 4 
       FIG. 14  is a schematic diagram illustrating an exemplary arrangement of the source lines  15  in the present embodiment. In the present embodiment, the exemplary arrangement of the source lines in the areas  201 A to  201 D is different from that in Embodiment 2 described above. The following description describes configurations different from those in Embodiment 2. 
     As illustrated in  FIG. 14 , the source lines  15  routed from the terminal part  12   s  to the area  201 B pass through the frame region R 4  (second frame region) opposed to the frame region R 1 , and are routed inside the area  201 A. Further, the source lines  15  routed from the terminal part  12   s  to the area  201 C pass through the frame region R 4 , and are routed inside the area  201 D. In this example, the source lines  15  are formed in the same metal layer. In other words, in the present embodiment, the source lines  15   a  in the area  201 A and the source lines  15   b  in the area  201 B are connected, and the source lines  15   c  in the area  201 C and the source lines  15   d  in the area  201 D are connected. 
     The number of the source lines arranged in each area is M/4, as is the case with Embodiment 2. Besides, though the illustration is omitted in this drawing, in the area, the gate drivers  11  for driving the gate lines  13  are arranged in the area, and the terminal part  12   g  is arranged in the frame region R 1 . 
     Next, the following description describes a data signal writing operation in the present embodiment.  FIG. 15  illustrates a timing chart of a data signal writing operation in the present embodiment. As is the case with  FIG. 7  mentioned above, the waveforms of the gate lines  13 ( 1 ) to  13 (N) in this diagram are waveforms during one horizontal scanning period ( 1 H) that is latter one of two horizontal scanning periods ( 2 H) when the gate lines  13  have a potential at the H level. In other words, the waveforms of the gate lines  13 ( n ) in  FIG. 15  are waveforms of the gate lines  13 ( n ) during one horizontal scanning period from time t 3  to time t 4  illustrated in  FIG. 6 . 
     The present embodiment is identical to Embodiment 2 in the point that the writing of data signals to the areas  201 B and  201 D is performed after the writing of data signals in the areas  201 A and  201 C, but the present embodiment is different from Embodiment 2 in the following point. 
     As illustrated in  FIG. 15 , the gate lines  13  in the area  201 A are sequentially driven, and at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13  in the area  201 A, data signals Da( 1 , j) . . . Da(N, j) for the area  201 A are input through the terminal part  12   s  to the source lines  15   b ( h ) (h=M/4−j+1, j: integer, 1≦j≦M/4) in the area  201 B. This causes the data signals Da( 1 , j) . . . Da(N, j) to be input to the source lines  15   a ( j ) in the area  201 A, whereby data signals are written in all of the pixels in the area  201 A. 
     Likewise, the gate lines  13  in the area  201 C are sequentially driven, and at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13  in the area  201 C, data signals Dc( 1 , j) . . . Dc(N, j) for the area  201 C are input through the terminal part  12   s  to the source lines  15   c ( j ) in the area  201 C, whereby data signals are written in all of the pixels in the area  201 C. 
     Next, after the writing of data signals to the areas  201 A and  201 C, the gate lines  13  in the area  201 B and the area  201 D are driven sequentially. At respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13  in the area  201 B, data signals Db( 1 , h) . . . Db(N, h) for the area  201 B are input through the terminal part  12   s  to the source lines  15   b ( h ). Thereby, data signals are written in all of the pixels in the area  201 B. 
     Likewise, the gate lines  13  in the area  201 D are sequentially driven, and at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13  in the area  201 D, data signals Dd( 1 , h) . . . Dd(N, h) for the area  201 D are input through the terminal part  12   s  to the source lines  15   d ( h ) in the area  201 D, whereby data signals are written in all of the pixels in the area  201 D. 
     Incidentally, in the present embodiment, as the set signal S for the gate driver  11 ( 1 ) in the area  201 B, the voltage of the gate line  13 (N) in the area  201 A may be input in place of the startpulse signal SPb. Further, as the set signal S for the gate driver ( 1 ) in the area  201 D, the voltage of the gate line  13 (N) in the area  201 C may be input in place of the startpulse signal SPd. Alternatively, a common startpulse signal may be supplied to the gate drivers  11 ( 1 ) in the areas  201 A and  201 C, and a common startpulse signal may be supplied to the gate drivers  11 ( 1 ) in the areas  201 C and  201 D. 
     Each source line  15  may be formed in the same metal layer, or may be formed in the following manner.  FIG. 16A  is a schematic diagram illustrating parts of the source lines  15  in the broken line frame P illustrated in  FIG. 14 .  FIG. 16B  is a cross-sectional view taken along line II-II in the portions of the source lines  15  illustrated in  FIG. 16A . As illustrated in  FIGS. 16A and 16B , the source lines  15  are formed at uniform intervals in the first metal layer  1300  on the substrate  1000  that composes the active matrix substrate  20   a . On an insulating film  1100  formed on the first metal layer  1300 , a second metal layer  1500  is formed, and in the second metal layer  1500 , source lines  15  are further formed at positions between the source line  15  and the source line  15  on the first metal layer  1300 . In this way, in the frame region R 1 , the source lines  15  formed in the first metal layer  1300 , and the source lines  15  formed in the second metal layer  1500  are alternately arranged. 
     The source lines  15  arranged in the areas  201 A to  201 D and the frame region R 4  are formed in the second metal layer  1500 . The source lines  15  formed in the first metal layer  1300 , therefore, are connected with the source lines  15  arranged in the areas  201 A to  201 D, through the contact holes formed in the insulating film  1100 . 
     In Embodiment 4, the source lines  15  do not intersect in the frame region R 1 . As illustrated in  FIGS. 16A and 16B , therefore, the portions of the source lines  15  arranged in the frame region R 1  are formed alternately in the first metal layer  1300  and the second metal layer  1500 , whereby the source lines  15  arranged in the frame region R 1  can be arranged at smaller intervals. As a result, as compared with the case where the portions of the source lines  15  arranged in the frame region R 1  are formed in the same layer, the frame region R 1  for routing the source lines  15  is allowed to have a smaller width L. 
     The example illustrated in  FIG. 16B  is an example in which the source lines  15  formed in the second metal layer  1500  and the source lines  15  formed in the first metal layer  1300  are arranged so as to be adjacent to each other in the horizontal direction of the active matrix substrate  20   a , but the source lines  15  arranged in the frame region R 1  may be configured as illustrated in  FIG. 16C , for example. In other words, as illustrated in  FIG. 16C , the source lines  15  formed in the second metal layer  1500  may be arranged so as to overlap the source lines  15  formed in the first metal layer  1300 , with the insulating film  1100  being interposed therebetween. 
     Embodiment 5 
     The present embodiment is different from Embodiment 2 regarding the configuration illustrated in  FIG. 9  in which the source line portions  150   d  and the source lines  15   c  are connected. The following description describes the configuration different from that of Embodiment 2. 
       FIG. 17A  is an enlarged schematic diagram illustrating a connection part where the source line portions  150   d  and the source lines  15   c  illustrated in  FIG. 9  are connected.  FIG. 17B  is a cross-sectional view of the connection part of the source line portions  150   d  and the source lines  15   c  illustrated in  FIG. 17A , the view being taken long line III-III. 
     As illustrated in  FIG. 17A , the source line portions  150   d  are connected with connection lines  161 , and are connected with the source lines  15   c  through the connection lines  161 . More specifically, as illustrated in  FIG. 17B , the source line portions  150   d  are formed at uniform intervals in the first metal layer  1300  on the substrate  1000 , and the insulating film  1100  is formed so as to cover the source line portions  150   d . In the second metal layer  1500  on the insulating film  1100 , the source line portions  150   d  are formed at positions between the source line portions  150   d  formed in the first metal layer  1300 . Then, the insulating film  1200  is formed so as to cover the source line portions  150   d  formed in the second metal layer  1500 , and the connection lines  161  are formed in a third metal layer  1600  on the insulating film  1200 . The connection lines  161  are connected with the source line portions  150   d  and the source lines  15   c  formed in the second metal layer  1500 , through contact holes provided in the insulating film  1200 . 
     Though illustration is omitted, the source line portions  150   d  formed in the first metal layer  1300  are connected with the connection lines  161  through the contact holes provided in the insulating film  1200  and the insulating film  1100 . Further, the source line portions  150   d  formed in the first metal layer  1300  are connected with the source lines  15   d  in the area  201 D, through the contact holes provided in the insulating films  1200  and  1100 . 
     The example described above is referred to when the structure of connection of the source line portions  150   d  and the source lines  15   c  is described, and the structure of connection of the source lines  15   b  in the area  201 B and the source line portions  150   a  in the frame region R 1  is identical to the above-described structure of connection. 
     In Embodiment 5 described above, the source line portions in one area in the frame region R 1  are alternately formed in the first metal layer  1300  and the second metal layer  1500 , and the source line portions and the source lines  15  in the other areas are connected through the connection lines  161  formed in the third metal layer  1600 . As compared with a case where all of the source line portions in the frame region R 1  are formed in the same layer, the source line portions can be arrange at smaller intervals, whereby the frame region R 1  for routing the source lines is allowed to have a smaller width L as compared with Embodiment 2. 
     Embodiment 6 
     Embodiment 2 is described with reference to an exemplary case where the pixels corresponding to R, G, and B of the color filters are arrayed in the order of R, G, B along the gate line  13  extending direction. The present embodiment is described with reference to an exemplary case where the pixels corresponding to R, G, and B of the color filters are arrayed in the order of R, G, B along the source line  15  extending direction. 
       FIG. 18  is a schematic diagram illustrating a schematic configuration of the active matrix substrate  20   a  in the present embodiment. As illustrated in  FIG. 18 , each of the areas  201 A to  201 D of the active matrix substrate  20   a ,  3 N gate lines  13  ( 13 ( 1 ) to  13 ( 3 N)), and M/12 source lines  15 ( 1 ) to  15 (M/12) are arranged. In other words, each of the areas  201 A to  201 D in the present embodiment includes the gate lines  13  the number of which is three times the number thereof in Embodiment 2, and the source lines  15  the number of which is ⅓ of the number thereof in Embodiment 2. Though illustration is omitted in  FIG. 18 , in the pixels in each area, gate drivers  11  for diving the gate lines  13  in the area are provided, and a terminal part  12   g  is provided in the frame region R 1 . 
       FIG. 19  illustrates a timing chart of a data signal writing operation in the present embodiment. As is the case with  FIG. 7  mentioned above, the waveforms of the gate lines  13 ( 1 ) to  13 (N) in this diagram are waveforms during one horizontal scanning period ( 1 H) that is latter one of two horizontal scanning periods ( 2 H) when the gate lines  13  have a potential at the H level. In other words, the waveforms of the gate lines  13 ( n ) in  FIG. 19  are waveforms of the gate lines  13 ( n ) during one horizontal scanning period from time t 3  to time t 4  illustrated in  FIG. 6 . In the present embodiment as well, as is the case with Embodiment 2, after the writing of data signals in the areas  201 A and  201 C is performed, the gate lines  13  in the areas  201 B and  201 D are driven, and data signals are written in the pixels in the areas  201 B and  201 D. 
     The timing chart illustrated in  FIG. 19  is different from the timing chart in Embodiment 2 illustrated in  FIG. 10  in the following point:  3 N gate lines  13 ( 1 ) to  13 ( 3 N) are sequentially driven in each area, and data signals for the pixels in the first to  3 K-th rows in the foregoing area are supplied to the source lines  15  in the foregoing area at the timings when the gate lines  13 ( 1 ) to  13 ( 3 N) are sequentially driven. 
     For example, the gate lines  13 ( 1 ) to  13 ( 3 N) in the area  201 A are sequentially driven, and at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( 1 ) to  13 ( 3 N) in the area  201 A, the display control circuit  4  supplies, to the terminal part  12   s , data signals Da( 1 , j) . . . Da( 3 N, j) for the pixels in the first to  3 N-th rows in the area  201 A. In the present embodiment, however, “j” satisfies 1≦j≦M/12. This allows data signals Da( 1 , j) . . . Da( 3 N, j) to be input to the source lines  15 ( 1 ) to  15 (M/12) in the area  201 A, whereby data signals are written in all of the pixels in the area  201 A. The data signal writing operations with respect to the other areas  201 B to  201 D are identical to the data signal writing operation with respect to the area  201 A. 
     While the number of the source lines  15  routed from the terminal part  12   s  to the frame region R 1  is M/2 In Embodiment 2 described above, the number of the same is M/6 in Embodiment 6 described above. In Embodiment 6, therefore, the width L for routing the source lines  15  from the terminal part  12   s  to the frame region R 1  can be further reduced, as compared with Embodiment 2. 
     Embodiment 7 
     The description of the present embodiment describes an exemplary case where data signal writing with respect to specific pixels in a part of areas in Embodiment 2 is performed at a frame frequency of, for example, 60 Hz, and data signal writing with respect to the other pixels is performed at a frame frequency of, for example, 1 Hz. 
       FIG. 20  is a schematic diagram illustrating a schematic configuration of an active matrix substrate  20   a  in the present embodiment. On the active matrix substrate  20   a  illustrated in  FIG. 20 , as is the case with the configuration illustrated in  FIG. 9 , N gate lines  13 ( 1 ) to  13 (N) are provided in each of the areas  201 A to  201 D, and M/2 source lines  15  are routed from the terminal part  12   s.    
     In the present embodiment, data signal writing with respect to a part of pixels in the areas  201 B and  201 C in a dashed dotted line frame Q in  FIG. 20  is performed at a frame frequency of 60 Hz, data signal writing with respect to the other pixels is performed at a frame frequency of 1 Hz. 
     Though illustration is omitted in  FIG. 20 , gate drivers for driving the gate lines  13  in each area are arranged in the pixels in the area, and a terminal part  12   g  is arranged in the frame region R 1 . 
       FIG. 21  illustrates an equivalent circuit of the gate driver in the present embodiment. The configuration of the gate driver  110  in the present embodiment is different from the configuration of the gate driver  11  in Embodiment 2 in the following point. 
     The gate driver  110 ( n ) includes TFTs-A to -M, and TFT-P, as well as internal lines netA(n), netB(n), and netC(n). 
     To netA(n) in the gate driver  110 ( n ), the source terminal of TFT-B, the drain terminals of TFT-A, TFT-C, and TFT-K, the gate terminals of TFT-F and TFT-P, and one of electrodes of the capacitor Cbst are connected. 
     To netB(n), the source terminal of TFT-G, the drain terminals of TFT-H, TFT-I, and TFT-J, and the gate terminals of TFT-C and TFT-M are connected. 
     To netC(n), the source terminal of TFT-F, the capacitor Cbst, the drain terminal of TFT-E, and the drain terminal of TFT-D are connected. The voltage R(n) of netC(n) is input to the gate terminal of TFT-L of the gate driver  110 ( n −2) for driving the gate line  13 ( n −2). 
     Regarding TFT-F, the gate terminal thereof is connected with netA(n), the clock signal CKA is supplied to the drain terminal thereof, and the source terminal thereof is connected to netC(n). 
     Regarding TFT-E, the reset signal CLR is supplied to the gate terminal thereof, the drain terminal thereof is connected to netC(n), and the power source voltage signal VSS is supplied to the source terminal thereof. 
     Regarding TFT-D, the clock signal CKB is supplied to the gate terminal thereof, the drain terminal thereof is connected to netC(n), and the power source voltage signal VSS is supplied to the source terminal thereof. 
     Regarding TFT-L, the gate terminal thereof is connected with netC(n+2) in the gate driver  110 ( n +2) for driving the gate line  13 ( n +2), the drain terminal thereof is connected with the gate line  13 ( n ), and the power source voltage signal VSS is supplied to the source terminal thereof. 
     Regarding TFT-N, the reset signal CLR is supplied to the gate terminal thereof, the drain terminal thereof is connected with the gate line  13 ( n ), and the power source voltage signal VSS is supplied to the source terminal thereof. 
     Regarding TFT-M, the gate terminal thereof is connected with netB(n), the drain terminal thereof is connected with the gate line  13 ( n ), and the power source voltage signal VSS is supplied to the source terminal thereof. 
     Regarding TFT-P, the gate terminal thereof is connected with netA(n), a row selection signal ENA to be described below is supplied to the drain terminal thereof, and the source terminal thereof is connected with the gate line  13 ( n ). 
     Regarding TFT-K, the gate terminal thereof is connected with netA(n+2), the clock signal CKA is supplied to the drain terminal thereof, and the source terminal thereof is connected with netA(n). 
     Regarding TFT-J, the gate terminal thereof is connected with netA(n), the drain terminal thereof is connected with netB(n), and the power source voltage signal VSS is supplied to the source terminal thereof. 
     In Embodiment 2, to the gate terminal of the TFT-J, the adjacent gate line  13 ( n −1) is connected, but in the present embodiment, the adjacent the gate line  13 ( n −1) is not driven in some cases. In the present embodiment, therefore, the configuration is such that the voltage of the adjacent gate line  13  should not be input to the gate driver  110 ( n ). 
     The row selection signal is a signal that exhibits a potential at the H level (VDD) or the L level (VSS). The display control circuit  4  supplies, as control signals, any one of row selection signals ENA, ENB, ENC, and END in addition to the clock signals, to the drain terminal of TFT-P in each gate driver  110 . 
     Next, the following description describes an arrangement layout of elements that compose the gate driver  110 , while referring to  FIGS. 22A to 22E .  FIGS. 22A to 22E  are schematic diagram illustrating an exemplary arrangement of elements in the gate driver  110 ( n ), and the gate driver  110 ( n −2) for driving the gate line  13 ( n −2). 
     Though the description of “TFT-” is omitted in  FIGS. 22A to 22E  for convenience sake, TFTs denoted by alphabetic characters in each drawing corresponding to TFTs denoted by the same alphabetic characters in  FIG. 21 .  FIGS. 22A and 22B  are continuous to each other at the column S 1  in each drawing, and  FIGS. 22B and 22C  are continuous to each other at the column S 2  in each drawing. Further,  FIGS. 22C and 22D  are continuous at the column S 3  in each drawing, and  FIGS. 22D and 22E  are continuous to each other at the column S 4  in each drawing. 
     As illustrated in  FIGS. 22A to 22E , TFTs-A to -M, TFT-P, netA(n), netB(n), and netC(n) of the gate driver  110 ( n ) are arranged in a space between the gate line  13 ( n ) and the gate line  13 ( n +2). Further, TFTs-A to -M, TFT-P, netA(n−2), netB(n−2), and netC(n−2) of the gate driver  110 ( n −2) are arranged in a space between the gate line  13 ( n −2) to the gate line  13 ( n ). 
     As illustrated in  FIG. 22C , TFT-P is formed with three TFTs-P that are connected in parallel. Though TFT-P is formed with three TFTs connected in parallel in this example, the number of TFTs is not limited to this. The drain terminal of each TFT-P in the gate driver  110 ( n ) is connected to the control line  16  to which the row selection signal ENA is supplied. On the other hand, the drain terminal of each TFT-P in the gate driver  110 ( n −2) is connected with the control line  16  to which the row selection signal ENB is supplied. 
     Though illustration is omitted, the drain terminal of TFT-P in the gate driver  110 ( n −1) for driving the gate line  13 ( n −1) is connected with the control line  16  to which the row selection signal END is supplied. Further, the drain terminal of TFT-P in the gate driver  110 ( n +1) for driving the gate line  13 ( n +1) is connected with the control line  16  to which the row selection signal ENC is supplied. Further, the drain terminal of each TFT-P in the gate driver  110 ( n +2) for driving the gate line  13 ( n +2) is connected with the control line  16  to which the row selection signal ENB is supplied. 
     Further, as illustrated in  FIG. 22D , TFT-L is formed with three TFTs-L connected in parallel. Though TFT-L is formed with three TFTs connected in parallel in this example, the number of TFTs is not limited to this. The gate terminal of each TFT-L in the gate driver  110 ( n ) is connected with netC(n+2) in the gate driver  110 ( n +2), and the voltage R(n+2) of netC(n+2) is input thereto. The gate terminal of each TFT-L in the gate driver  110 ( n −2) is connected with netC(n), and the potential R(n) of netC(n) is input thereto. In  FIG. 22D , the control line  16  to which the direct current voltage signal at the L level (VSS) is supplied is connected with the source terminal of each TFT-L in the gate driver  110 ( n ) and the gate driver  110 ( n −2). 
     In  FIG. 22E , netC(n) in the gate driver  110 ( n ) is connected to the gate terminal of TFT-L in the gate driver  110 ( n −2) illustrated in  FIG. 22D . Further, netC(n−2) in the gate driver  110 ( n −2) is connected to the gate terminal of TFT-L in the gate driver  110 ( n −4), which is not illustrated. 
     Next, the following description describes operations of the gate driver  110 ( n ) in the present embodiment.  FIG. 23  illustrates a timing chart in a case where arbitrary gate lines  13  ( 13 ( n −1) to  13 (n+1)) in one area is driven in one frame, and the driving of other gate lines  13  ( 13 ( n −2),  13 (n+2)) is stopped. 
     The display control circuit  4  supplies row selection signals END, ENA, and ENC of a voltage at the H level to the gate driver  110 ( n −1), the gate driver  110 ( n ), and the gate driver  110 ( n +1) at the timings when the potentials of netA(n−1), netA(n), netA(n+1) rise to the H level. Further, the display control circuit  4  supplies the row selection signal ENB that has a L level voltage during one frame to the gate driver  110 ( n −2) and the gate driver  110 ( n +2). 
     Referring to  FIGS. 21 and 23 , the clock signals CKD and the potential of netA(n−2) are at the H level at time t 1 . At time t 1 , therefore, TFT-B of the gate driver  110 ( n ) is in the ON state, and the potential at the H level (VDD) of the clock signal CKD is precharged through TFT-B to netA(n). This causes TFT-P of the gate driver  110 ( n ) to be turned ON. At time t 1 , since the potential of the row selection signal ENA is at the H level, the gate line  13 ( n ) is charged to the potential of (VDD minus the threshold voltage of TFT-P) through TFT-P. Further, here, TFT-F is also turned ON, but since the potential of the clock signal CKA is at the L level, the potential R(n) of netC(n) is maintained at the L level. 
     At time t 2 , the potential of the clock signal CKA rises to the H level. Since TFT-F of the gate driver  110 ( n ) is in the ON state, a voltage at the H level of the clock signal CKA is input to netC(n) through TFT-F. As the potential of netC(n) rises, the potential of netA(n) is boosted through the capacitor Cbst, and is charged to the potential greater than (VDD plus the threshold voltage of TFT-P) (hereinafter referred to as “main charge”). Here, since TFT-P of the gate driver  110 ( n ) is in the ON state and the potential of the row selection signal ENA is at the H level, a voltage at the H level is input to the gate line  13 ( n ), whereby the gate line  13 ( n ) shifts to the selected state. 
     At time t 3 , the potential of the clock signal CKA is at the H level, netA(n) maintains the potential at the H level, and TFT-F and TFT-P are in the ON state. The gate line  13 ( n ) therefore remains in the selected state. 
     From time t 4  to time t 5 , the potentials of the clock signal CKA and the row selection signal ENA fall to the L level, the potential of the clock signal CKB rises to the H level, netA(n+2) in the gate driver  110 ( n +2) is subjected to main charge, and the potential R(n+2) of netC(n+2) rises to the H level. This causes TFT-K and TFT-L in the gate driver  110 ( n ) to be turned ON. As a result, the potential of netA(n) is pulled down to the L level (VSS) through TFT-K, and the voltage at the L level (VSS) is applied through TFT-L to the gate line  13 ( n ). Here, TFT-P of the gate driver  110 ( n +2) is in the ON state, but since the potential of the row selection signal ENB is at the L level, the potential of the gate line  13 ( n +2) remains at the L level. 
     After time t 6 , since the potential R(n+2) of netC(n+2) and netA(n+2) fall to the L level, TFT-K and TFT-L of the gate driver  110 ( n ) are turned OFF, but at the timing when the potential of the clock signal CKD rises to the H level, a voltage at the H level is input to netB(n), whereby TFT-C and TFT-M are turned ON. NetA(n) is maintained at the potential at the L level through TFT-C, and the gate line  13 ( n ) is maintained at the potential at the L level through TFT-M. 
     The gate driver  110 ( n −2), the gate driver  110 ( n −1), and the gate driver  110 ( n +1) are driven in the same manner as the gate driver  110 ( n ). In other words, from time t 0  to time t 2 , netA(n−2) in the gate driver  110 ( n −2) is subjected to main charge as the potential R(n−2) of netC(n−2) rises, but since the potential of the row selection signal ENB is at L level, the potential of the gate line  13 ( n −2) remains at the L level. From time t 1  to t 3 , netA(n−1) of the gate driver  110 ( n −1) is subjected to main charge as the potential R(n−1) of netC(n−1) rises. Here, since the potential of the row selection signal END is at the H level, the gate line  13 ( n −1) shifts to the selected state. From time t 3  to time t 5 , netA(n+1) in the gate driver  110 ( n +1) is subjected to main charge as the potential R(n+1) of netC(n+1) rises. Here, since the potential of the row selection signal ENC is at the H level, the gate line  13 ( n +1) shifts to the selected state. 
     In this way, the row selection signal of a voltage at the H level is supplied to the gate driver  110  corresponding to the gate line  13  to be driven, during a period while the gate line  13  is to be driven, and the row selection signal of a voltage at the L level is supplied to the gate driver  110  corresponding to the gate line  13  not to be driven, during a period of one frame. This makes it possible to drive only arbitrary gate lines  13  during one frame period. 
     Next, the following description describes the data signal writing operation in the present embodiment.  FIG. 24A  is a timing chart of a data signal writing operation with respect to the first frame among sixty frames. As is the case with  FIG. 7  mentioned above, the waveforms of the gate lines  13 ( 1 ) to  13 (N) in this diagram are waveforms during one horizontal scanning period ( 1 H) that is latter one of two horizontal scanning periods ( 2 H) when the gate lines  13  have a potential at the H level. In other words, the waveforms of the gate lines  13 ( n ) in  FIG. 24A  are waveforms of the gate lines  13 ( n ) during one horizontal scanning period from time t 3  to time t 4  illustrated in  FIG. 6 . Further, in  FIG. 24A , for convenience sake, the row selection signals (ENA to END) supplied to the gate drivers  110  in the areas  201 A and  201 B,  201 C, and  201 D are referred to generally as EN 1 , EN 2 , EN 3 , and EN 4 , respectively. 
     In the present embodiment, regarding the first frame, as is the case with Embodiment 2 described above, all of the gate lines  13  in the areas  201 A and  201 C are sequentially driven so that data signal writing is performed with respect to the areas  201 A and  201 C, and thereafter, all of the gate lines  13  in the areas  201 B and  201 D are sequentially driven so that data signal writing is performed with respect to the areas  201 B and  201 D. 
     With respect to the first frame, the display control circuit  4  starts supplying the clock signals CKA to CKD to the gate drivers  110  in the area  201 A to  201 D, and as illustrated in  FIG. 24A , supplies row selection signals EN 1  to EN 4  of a voltage at the H level. This causes all of the gate lines  13  in the areas  201 A and  201 C to be sequentially driven, and at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13  in the areas  201 A and  201 C, the data signals Da (Da( 1 , j) . . . Da(N, j)) for the area  201 A, and the data signals Dc ((Dc( 1 , j) . . . Dc(N, j)) for the area  201 C, are supplied to the source lines  15   a ( j ) and the source lines  15   c ( j ), respectively. As a result, data signals are written in all of the pixels in the areas  201 A and  201 C. 
     After the writing of data signals in the areas  201 A and  201 C, startpulse signals SPb and SPd are supplied from the display control circuit  4  to the gate drivers  110 ( 1 ) in the areas  201 B and  201 D, whereby all of the gate line  13  in the areas  201 A and  201 C are sequentially driven. At respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13  in the areas  201 B and  201 D, data signals Db (Db( 1 , j) . . . Db(N, j)) for the area  201 B and, data signal Dd (Dd( 1 , j) . . . Dd(N, j)) for the area  201 D are supplied to the source lines  15   b ( j ) and the source lines  15   d ( j ), respectively. As a result, data signals are written in all of the pixels in the areas  201 B and  201 D. 
     The following description describes the data signal writing operation with respect to the second to sixtieth frames.  FIG. 24B  is a timing chart of a data signal writing operation in each frame period with respect to the second to sixtieth frames. In this drawing as well, as is the case with  FIG. 24A , the waveforms of the gate lines  13 ( 1 ) to  13 (N) in this diagram are waveforms during one horizontal scanning period ( 1 H) that is latter one of two horizontal scanning periods ( 2 H) when the gate lines  13  have a potential at the H level. 
     In the dashed dotted line frame Q illustrated in  FIG. 20 , which is arranged in the areas  201 B and  201 C, (s+1) gate lines  13 , i.e., gate lines  13 ( k ) to  13 ( k +s) (k, s: integers, 1≦k&lt;N, 1≦s&lt;N−2) are arranged. In this example, the gate lines  13 ( k ) to  13 ( k +s) arranged in the areas  201 B and  201 C are driven at 60 Hz, and the other gate lines  13  are driven at 1 Hz. 
     As illustrated in  FIG. 24B , the display control circuit  4  supplies startpulse signals SPa and SPc to the gate drivers  110 ( 1 ) in the areas  201 A and  201 C at the start of each frame, supplies the row selection signal EN 1  having a potential at the L level to the gate drivers  110  in the area  201 A in each frame period, and does not supply data signals to the source lines  15   a ( j ) in the area  201 A. 
     Further, as  FIG. 24B , the display control circuit  4  supplies the row selection signal EN 3  having a potential at the H level to the gate drivers  110  in the area  201 C during each frame period, at timings of driving the gate lines  13 ( k ) to  13 ( k +s) in the area  201 C. Further, the display control circuit  4  supplies, to the source lines  15   d ( j ), data signals Dc (Dc(k, j) . . . Dc(k+s, j) for respective pixels that are formed by the gate lines  13 ( k ) to  13 ( k +s), at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( k ) to  13 ( k +s). 
     This causes all of the gate lines  13  in the area  201 A to have a potential at the L level in each frame period of the second to sixtieth frames, whereby data signals are written in none of the pixels in the area  201 A. Further, in the area  201 C, the gate lines  13  except for the gate lines  13 ( k ) to  13 ( k +s) have a potential at the L level, whereby only the gate lines  13 ( k ) to  13 ( k +s) are driven. As a result, the data signals Dc are input through the source lines  15   d ( j ) to the source lines  15   c ( j ), whereby data signals are written in the respective pixels formed by the gate lines  13 ( k ) to  13 ( k +s) in the area  201 C. 
     After the data signal writing in the area  201 C, as illustrated in  FIG. 24B , the display control circuit  4  supplies the startpulse signals SPb and SPd to the gate drivers  110 ( 1 ) in the areas  201 B and  201 D, supplies the row selection signal EN 4  having a voltage at the L level to the gate drivers  110  in the area  201 D, and does not supply data signals to the source lines  15   d ( j ) in the area  201 D. 
     Further, as illustrated in  FIG. 24B , the display control circuit  4  supplies the row selection signal EN 2  having a voltage at the H level to the gate drivers  110  in the area  201 B at timings of driving the gate lines  13 ( k ) to  13 ( k +s) in the area  201 B. Further, the display control circuit  4  supplies, to the source lines  15   a ( j ), data signals Db (Db(k, j) . . . Db(k+s, j) for respective pixels that are formed by the gate lines  13 ( k ) to  13 ( k +s) in the area  201 B, at respective timings when one horizontal scanning period ( 1 H) elapses from the respective starts of driving of the gate lines  13 ( k ) to  13 ( k +s). 
     This causes all of the gate lines  13  in the area  201 D to have a potential at the L level in each frame period of the second to sixtieth frames, whereby data signals are written in none of the pixels in the area  201 D. Further, in the area  201 B, the gate lines  13  except for the gate lines  13 ( k ) to  13 ( k +s) have a potential at the L level, whereby only the gate lines  13 ( k ) to  13 ( k +s) are driven. As a result, the data signals Db are input through the source lines  15   a ( j ) to the source lines  15   b ( j ), whereby data signals of each frame are written in the respective pixels formed by the gate lines  13 ( k ) to  13 ( k +s) in the area  201 B. 
     In this way, in Embodiment 7 described above, arbitrary gate lines  13  can be driven with a certain frame frequency, and the other gate lines  13  can be driven with a frame frequency lower than the foregoing frame frequency. This makes it possible to, for example, drive the gate lines  13  for the pixels displaying a still image with a low frame frequency (for example 1 Hz), and drive the gate lines  13  for the pixels displaying a moving image with a high frame frequency (for example, 60 Hz), whereby the electric power consumption needed for the data signal writing operation can be reduced. 
     Embodiment 8 
     Embodiments 1 to 7 described above are described with reference to an exemplary case where the active matrix substrate  20   a  includes the display region  200  in an approximately rectangular shape, but the shape of the display region is limited to the rectangular shape. 
     For example, as illustrated in  FIG. 25 , the active matrix substrate  20   a  may have a display region  200  in a circular shape composed of pixel groups formed in areas  201 A to  201 D in non-rectangular shapes. In each of the areas  201 A to  201 D, a plurality of gate lines  13  and a plurality of source lines  15  are arranged. 
     Though illustration is omitted in  FIG. 25 , gate drivers  11  for driving the gate lines  13  in each area are arranged in each area, as is the case with Embodiments 1 to 7 described above. In the example illustrated in  FIG. 25 , however, the columns do not have uniform numbers of pixels in each area, and therefore, the lengths of the gate lines  13  are not uniform. In this case, the gate driver  11  is provided to the gate line  13  provided in the column having the largest number of pixels among the columns in each area. 
     Further, as illustrated in  FIG. 25 , the terminal part  12   s  for supplying data signals to the source lines  15  in each area is arranged in the frame region R 1 . As is the case with Embodiment 2 described above, the source lines  15  in the area  201 A and those in the area  201 D are routed form the terminal part  12   s  so as to be approximately horizontally symmetric with respect to the boundary between the area  201 B and the area  201 C interposed therebetween. In the frame region R 1 , the source lines  15   b  and  15   c  in the areas  201 B and  201 C are connected to the source line portions  150   a  and  150   d  in the frame region R 1 . 
     In the present embodiment as well, as is the case with Embodiment 2, the number of source lines routed in the frame region R 1  is only M/4, and this allows the frame region R 1  to have a smaller width L as compared with the case of Embodiment 1. Further, by arranging the gate driver  11  in each area, not only the frame region R 1  but also frame regions in outer edge portions of the display region  200  can be narrowed, which makes it possible to produce a display panel in a non-rectangular shape. 
     The embodiments of the present invention, described above, are merely examples for implementing the present invention. The present invention, therefore, is not limited to the above-described embodiments, and any of the above-described embodiments can be modified appropriately without departing from the scope of the invention so that the present invention is implemented. The following description describes modifications of the present invention. 
     &lt;Modification&gt; 
     (1) In Embodiments 1 to 8, the source lines  15  in one of adjacent areas are routed from the terminal part  12   s , and the source lines  15  in the other area are connected to the source lines  15  in the one area in the frame region R 1  where the terminal part  12   s  is provided. The connection, however, may be as follows. 
       FIG. 26  is a schematic diagram illustrating an exemplary connection of source lines on an active matrix substrate in a modification example of the present invention. As is the case with Embodiment 2, independent gate lines  13 ( 1 ) to  13 (N) are formed in the areas  201 A to  201 D. 
     As illustrated in  FIG. 26 , in the present modification example, source lines  15   b  and  15   c  are respectively routed from the terminal part  12   s  to the area  201 B and the area  201 C. In the area  201 A and the area  201 D, source lines  15   a  and  15   d  that intersect with all of the gate lines  13  ( 13 ( 1 ) to  13 (N)) (for example, see  FIG. 10 ) provided in the foregoing areas are provided. In the area  201 A and the area  201 B, connection lines  151  each of which connects one source line  15   a  and one source line  15   b  corresponding to the source line  15   a  are provided. Further, in the area  201 C and the area  201 D, connection lines  152  each of which connects one source line  15   c  and one source line  15   d  corresponding to the source line  15   c  are provided. The connection lines  151  and  152  are formed in the same layer as the gate lines  13 . 
     Since the source lines  15   a  in the area  201 A are connected through the connection lines  151  with the source lines  15   b  in the area  201 B, respectively, data signals for the area  201 A supplied from the terminal part  12   s  can be received through the source lines  15   b  and the connection lines  151 . Further, since the source lines  15   d  in the area  201 D are connected through the connection lines  152  with the source lines  15   c  in the area  201 C, respectively, data signals from the terminal part  12   s  for the area  201 D can be received through the source lines  15   c  and the connection lines  152 . 
     In this example, the gate lines  13  in the area  201 B and the area  201 C are driven by the gate drivers  11  in the area  201 B and the area  201 C, so that data signals are written in the area  201 B and the area  201 C. During this period, the gate lines  13  in the area  201 A and the area  201 D are not driven. By so doing, data signals of the area  201 B and the area  201 C are input to the source lines  15   a  and  15   d  in the area  201 A and the area  201 D through the connection lines  151  and  152 , but the data signals are not written in the area  201 A and the area  201 D. 
     Further, after data signals are written in the area  201 B and the area  201 C, the gate lines  13  in the area  201 A and the area  201 D are driven by the gate drivers  11  in the area  201 A and the area  201 D, whereby data signals are written in the area  201 A and the area  201 D. During this period, the gate lines  13  in the area  201 B and the area  201 C are not driven. This allows data signals in the area  201 A and the area  201 D to be input to the source lines  15   b ,  15   c  in the area  201 B and the area  201 C, but the data signals are not written in the area  201 B and the area  201 C. 
     The parts of the source lines  15   b  and  15   c  arranged in the frame region R 1  may be arranged alternately in the first metal layer  1300  and the second metal layer  1500 , as is the case with Embodiment 5 described above. With such a configuration, the frame region R 1  can have a further smaller width L 1 . 
     (2) In Embodiments 1, 3, 6, 7, and 8 described above, the source line portions in one area arranged in the frame region R 1 , and the source lines in another area adjacent to the foregoing one area, may be connected by using the connection lines  131 , as is the case with Embodiment 2. The source line portions in one area arranged in the frame region R 1  may be formed alternately in the first metal layer  1300  and the second metal layer  1500 , and may be connected with the source lines in another area by using the connection lines  161  formed in the third metal layer  1600 , as is the case with Embodiment 5. 
     (3) Embodiments 1 to 8 described above are described with reference to an example in which the source lines  15  in one area connected with the terminal part  12   s  are connected with the source lines  15  in one area adjacent to the foregoing one area, but the configuration may be as follows. For example, in a case where a display region  200  composed of three areas having independent pixel groups, respectively, is provided on the active matrix substrate  20   a , the source lines  15  in one area connected to the terminal part  12   s  may be connected with the source lines  15  in the two other areas. In this case, the following control is performed: the gate lines  13  are driven area by area according to a preliminarily determined order in which the gate lines of the three areas are driven, and data signals to be written in the area are supplied thereto. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
           1  . . . liquid crystal display device 
           1 ,  2  . . . display panel 
           3  . . . source driver 
           4  . . . display control circuit 
           5  . . . power source  5   
           11 ,  110  . . . gate driver 
           12   g ,  12   s  . . . terminal part 
           13  . . . gate line 
           15  . . . source line 
           16  . . . control line 
           20   a  . . . active matrix substrate 
           20   b  . . . counter substrate 
           131 ,  151 ,  152 ,  161  . . . connection line 
           150 ,  150   a  to  150   d  . . . source line portions 
           200  . . . display region 
           201 A to  201 D . . . area 
           1300  . . . first metal layer 
           1500  . . . second metal layer 
           1600  . . . third metal layer 
         R 1  to R 4  . . . frame region 
         SW 1 , SW 2  . . . switching element