JP2006215176A - Liquid crystal display panel and liquid crystal display (lcd) driver chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display panel wherein quality of a display image is heightened, relating to the liquid crystal display panel wherein a liquid crystal is encapsulated between a segment substrate on which segment electrodes are arranged and a common substrate on which common electrodes are arranged and the image is displayed by performing ON/OFF of the liquid crystal by performing On/Off of voltage application between the segment electrodes and the common electrodes and an LCD driver chip driving the liquid crystal display panel. <P>SOLUTION: Common transition point groups 12C1_1 and 12C1_2 to be connected directly to common electrodes 13a1, ... , 13a6, ... , 13a84 of a common glass 13 are provided at left and light sides of a segment glass 12, respectively, and common transition point groups 12C2_1 and 12C2_2 to be connected to common electrodes 13a85, ... , 13a161, 13a92, ... , 13a168 are provided at a lower side of the segment glass 12. Routing of wiring to the common electrodes 13a1, ... , 13a168 is assigned not only to the upper part of the segment glass 12 but also to the upper part of the common glass 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, a liquid crystal is sealed between a segment substrate on which segment electrodes are arranged and a common substrate on which common electrodes are arranged, and the liquid crystal is turned on and off by applying voltage between the segment electrodes and the common electrode. The present invention relates to a liquid crystal display panel that displays an image by turning on and off and an LCD driver chip that drives the liquid crystal display panel.

  Conventionally, between a segment substrate in which segment electrodes extending in a first direction in a predetermined screen area are arranged and a common substrate in which common electrodes extending in a second direction are arranged in a screen area overlapping the screen area. There is known a liquid crystal display panel in which a liquid crystal is sealed, and an image is displayed by turning on and off the liquid crystal by turning on and off the voltage application between the segment electrode and the common electrode. As such a liquid crystal display panel, a passive matrix (simple matrix) type liquid crystal display panel using STN (Super Twisted Nematic) liquid crystal is widely used.

  FIG. 4 is a diagram showing a simplified example of the structure of a conventional passive matrix liquid crystal display panel.

  FIG. 4A shows a front view of the passive matrix type liquid crystal display panel 100. FIG. 4B shows a side view of the passive matrix type liquid crystal display panel 100. Further, FIG. 4C shows a cross-sectional view of the passive matrix type liquid crystal display panel 100.

  As shown in FIG. 4A, the liquid crystal display panel 100 includes a segment glass 102 having a predetermined screen area 10a and a driver chip 11 fixed to a portion 10b excluding the screen area 10a. Yes. In addition, the liquid crystal display panel 100 includes a sealing portion 10c that surrounds a predetermined screen area 10a. Note that FIG. 4A shows a common transition portion A described later.

  Further, as shown in FIG. 4B, the liquid crystal display panel 100 is provided with a common glass 103 and a polarizing plate 14 so as to cover the screen region 10 a of the segment glass 102. Further, a polarizing plate 15 is provided at a portion of the segment glass 102 that faces the portion where the common glass 103 and the polarizing plate 14 are provided.

  4C, the liquid crystal display panel 100 includes a segment electrode 102a made of ITO (Indium Tin Oxide) arranged on the segment glass 102, and a color filter layer 16a constituting the color filter 16. And alignment films 17 and 18, and a common electrode 103 a made of ITO arranged on the common glass 103. In addition, the liquid crystal display panel 100 includes a liquid crystal 20 sealed between a segment glass 102 and a common glass 103 with a sealing agent 19 provided along the sealing portion 10c. Furthermore, the liquid crystal display panel 100 is also provided with a backlight unit 21 that is disposed on the common glass 103 side and that emits light.

  FIG. 5 is a plan view of segment glass and common glass constituting the liquid crystal display panel shown in FIG.

  FIG. 5A shows a plan view of the segment glass 102. FIG. 5B shows a plan view of the common glass 103.

  In the segment glass 102 shown in FIG. 5A, a large number of segment electrodes 102a extending in the vertical direction are arranged in the screen region 10a from the driver chip 11 fixed on the segment glass 102. Further, on the segment glass 102, a large number of common electrode wirings 102b extending in the vertical direction from the driver chip 11 on both sides of the screen region 10a are arranged. The large number of common electrode wirings 102b are connected to the large number of common transition points 102c provided in the common transition portion A.

  On the other hand, in the common glass 103 shown in FIG. 5B, a large number of common electrodes 103a extending in the horizontal direction in the screen region 10b overlapping the screen region 10a are arranged. The connection from the driver chip 11 fixed on the segment glass 102 to the common electrode 103a is as follows: driver chip 11 → common electrode wiring 102b → common transition point 102c → conductive particles contained in the sealant 19 → common electrode 103a. This is done in the wiring route.

  In the liquid crystal display panel 100 configured as described above, the liquid crystal 20 is turned on and off by turning on and off the voltage application between the segment electrode 102a and the common electrode 103a and irradiating light from the backlight unit 21. Is displayed.

In the passive matrix liquid crystal display panel having the above-described structure, a liquid crystal display panel in which more pixels and a larger display area are ensured (for example, refer to Patent Document 1), and the display quality is reduced by reducing the resistance of the wiring pattern. There has been proposed a liquid crystal display panel (see, for example, Patent Document 1) in which the image quality is increased.
JP 2000-250059 A JP 2003-222896 A

  In the conventional liquid crystal display panel including the liquid crystal display panel proposed in Patent Documents 1 and 2, when connecting the driver chip fixed on the segment glass to the common electrode arranged on the common glass, A large number of common electrode wirings extending on both sides of the screen area are required.

  In recent years, with the increase in the number of pixels of a liquid crystal display panel, the number of common electrodes also increases. As a result, the common electrode wiring of the segment glass extending on both sides of the screen region also increases. Here, the portion of the segment glass where the common electrode wiring is arranged in the screen region is a very small portion other than the display region. For this reason, if the common electrode wiring increases, the common electrode wiring per common electrode becomes thinner. Further, as shown in FIG. 5A, the common electrode wiring on the upper side of the segment glass becomes thinner and longer. As a result, a phenomenon occurs in which the common electrode wiring on the upper side of the segment glass has a high resistance. As a result, the signal waveform for image display from the driver chip becomes dull and the impedance matching accuracy between the segment glass and the common glass also decreases, resulting in image quality degradation due to crosstalk, uneven brightness, etc. There arises a problem that the quality of the image is degraded.

  In view of the circumstances described above, an object of the present invention is to provide a liquid crystal display panel with improved display image quality.

The liquid crystal display panel of the present invention that achieves the above-described object is provided with a segment substrate in which segment electrodes extending in a first direction in a predetermined screen region and a screen region that overlaps the screen region in a second direction. In the liquid crystal display panel in which the liquid crystal is sealed between the common substrate on which the electrodes are arranged and the liquid crystal is turned on and off by turning on and off the voltage application between the segment electrode and the common electrode.
The segment substrate has a common electrode wiring connected to a common electrode on the common substrate extending on both sides of the screen region, and the common electrode wiring is connected to the terminal common substrate. The first common electrode wiring connected directly to the common electrode from the common transition point of the first and the second common electrode wiring connected to the common electrode wiring extending from the common electrode on the common substrate from the second common transition point at the end thereof It is characterized by comprising the common electrode wiring.

  Since the liquid crystal display panel according to the present invention has the above-described configuration, the wiring to the common electrode is allocated not only on the segment substrate but also on the common substrate. As a result, a sufficient wiring area to the common electrode on the segment substrate can be secured. Accordingly, the wiring for the common electrode can be made thicker, and accordingly, image quality deterioration due to crosstalk, luminance unevenness and the like is suppressed, and the quality of the display image is improved.

  Here, the first common transition point is provided with a driver chip connected to the segment electrode and the common electrode fixed on the segment substrate and controlling voltage application between the segment electrode and the common electrode. Is preferably arranged farther from the driver chip than the second common transition point.

  The first common electrode wiring is directly connected to the common electrode from the first common transition point. On the other hand, the second common electrode wiring is connected to the common electrode from the second common transition point via the common electrode wiring. Therefore, in this way, it is possible to suppress the dullness of the entire signal waveform for image display output from the driver chip.

  According to the liquid crystal display panel of the present invention, the quality of the display image can be improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a plan view of segment glass and common glass of a liquid crystal display panel according to an embodiment of the present invention.

  In addition, the structure of the liquid crystal display panel of one Embodiment of this invention is replaced with the segment glass 102 and the common glass 103 by the segment glass 12 and the common glass 13 compared with the structure of the liquid crystal display panel 100 shown in FIG. Since it is the same except for the point, the structure of the liquid crystal display panel of one embodiment of the present invention is not shown. Further, the same constituent elements as those of the liquid crystal display panel 100 shown in FIG.

  FIG. 1A shows a plan view of a segment glass 12 (corresponding to an example of a segment substrate in the present invention) constituting a liquid crystal display panel according to an embodiment of the present invention. FIG. 1B shows a plan view of the common glass 13 (corresponding to an example of the common substrate in the present invention) constituting the liquid crystal display panel of one embodiment of the present invention. The liquid crystal display panel according to an embodiment of the present invention is a 128 × 168 size liquid crystal display panel.

  In the segment glass 12 shown in FIG. 1A, segment electrodes 12a1,..., 12a384 extending in a vertical direction (corresponding to the first direction in the present invention) in a predetermined screen area 10a are arranged.

  Further, the common glass 13 shown in FIG. 1B extends in the horizontal direction (corresponding to the second direction in the present invention) in the screen region 10b overlapping the screen region 10a. ..., 13a168 are arranged. This embodiment is an example in which 84 wirings to the 168 common electrodes 13a1,..., 13a168 are allocated on the segment glass 12 and 84 on the common glass 13, respectively.

  The segment glass 12 shown in FIG. 1A has common electrode wiring groups 12B1_1, 12B1_2, 12B2_1, and 12B2_2 connected to the common electrodes 13a1,..., 13a168 on the common glass 13 extending on both sides of the screen region 10a. . The common electrode wiring groups 12B1_1, 12B1_2, 12B2_1, and 12B2_2 correspond to an example of the common electrode wiring according to the present invention.

  Here, the common electrode wiring group 12B1_1 is composed of common electrode wirings 12b1,..., 12b7,..., 12b71 (corresponding to an example of the first common electrode wiring in the present invention). In addition, the common electrode wiring group 12B1_2 is composed of common electrode wirings 12b8,..., 12b15,..., 12b78, ..., 12b84 (corresponding to another example of the first common electrode wiring in the present invention). .

  Further, the common electrode wiring group 12B2_1 is composed of common electrode wirings 12b85,..., 12b161 (corresponding to an example of the second common electrode wiring in the present invention). The common electrode wiring group 12B2_2 is composed of common electrode wirings 12b92,..., 12b168 (corresponding to another example of the second common electrode wiring in the present invention).

  The segment glass 12 shown in FIG. 1A includes common transition point groups 12C1_1, 12C1_2, 12C2_1, and 12C2_2 connected to the common electrode wiring groups 12B1_1, 12B1_2, 12B2_1, and 12B2_2. The common transition point groups 12C1_1 and 12C1_2 are disposed farther from the driver chip 11 than the common transition point groups 12C2_1 and 12C2_2.

  Here, the common transition point group 12C1_1 is composed of common transition points 12c1, ..., 12c7, ..., 12c71, ..., 12c77 (corresponding to an example of the first common transition point in the present invention). The common transition point group 12C1_2 is composed of common transition points 12c8, ..., 12c15, ..., 12c78, ..., 12c84 (corresponding to another example of the first common transition point in the present invention).

  Further, the common transition point group 12C2_1 is composed of common transition points 12c85,..., 12c161 (corresponding to an example of a second common transition point in the present invention). The common transition point group 12C2_2 is composed of common transition points 12c92,..., 12c168 (corresponding to another example of the second common transition point in the present invention).

  On the other hand, common electrodes 13a1,..., 13a6,..., 13a84 directly connected from the common transition point groups 12C1_1 and 12C1_2 are arranged on the common glass 13 shown in FIG.

  Further, common electrodes 13 a 85,..., 13 a 161 are arranged on the common glass 13. These common electrodes 13a85,..., 13a161 are provided with common electrode wirings 13b85,..., 13b161 extending from these common electrodes 13a85,. Connection terminals 13c85,..., 13c161 are provided at the ends of the common electrode wirings 13b85,.

  Similarly, common electrodes 13 a 92,..., 13 a 168 are arranged on the common glass 13. The common electrodes 13a92,..., 13a168 are provided with common electrode wirings 13b92,..., 13b168 extending from the common electrodes 13a92,. Connection terminals 13c92,..., 13c168 are provided at the ends of the common electrode wirings 13b92,. Thus, in the present embodiment, wirings to the common electrodes 13a85,..., 13a168 are allocated on the common glass 13. The remaining common electrodes 13a1,..., 13a84 are assigned on the segment glass 12 in the same manner as the existing technology. As a result, the number of wires on the segment glass 12 is halved compared to the case of the conventional liquid crystal display panel, and a margin can be provided in the wiring region of the frame of the liquid crystal display panel. Considering simply, the width of the wiring can be doubled. Since the resistance value of the wiring is inversely proportional to the cross-sectional area of the wiring, the resistance of the routed wiring can be reduced.

  Here, the connection from the driver chip 11 fixed on the segment glass 12 to the common electrodes 13a1,..., 13a84 arranged on the common glass 13 is as follows: driver chip 11 → common electrode wiring group 12B1_1, 12B1_2 → common transition point Group 12C1_1, 12C1_2 → conductive particles (not shown) → common electrodes 13a1,.

  In addition, the connection from the driver chip 11 to the common electrodes 13a85,..., 13a161 arranged on the common glass 13 is as follows: driver chip 11 → common electrode wiring group 12B2_1 → common transition point group 12C2_1 → conductive particles → connection point 13c85,. , 13c161 → common electrode wirings 13b85,..., 13b161 → common electrodes 13a85,.

  Similarly, the connection from the driver chip 11 to the common electrodes 13a92,..., 13a168 arranged on the common glass 13 is as follows: driver chip 11 → common electrode wiring group 12B2_2 → common transition point group 12C2_2 → conductive particle → connection point 13c92. ,..., 13c168 → Common electrode wiring 13b92,..., 13b168 → Common electrodes 13a92,.

  FIG. 2 is an enlarged view of the driver chip shown in FIG.

  2 includes segment electrode terminals 11a1,..., 11a384 connected to the segment electrodes 12a1,..., 12a384 arranged on the segment glass 12 shown in FIG.

  The driver chip 11 includes common electrode terminals 11b1,..., 11b7, 11b15,..., 11b160, 11b161 connected to the common electrode wiring groups 12B1_1, 12B1_2, 12B2_1, 12B2_2 arranged on the segment glass 12. , 11b14, 11b22,..., 11b167, 11b168 are provided.

  The driver chip 11 further includes I / F terminals 11_1, 11_2,..., 11_n−1, 11_n for exchanging signals with an MPU I / F (not shown).

  This driver chip 11 allows the liquid crystal sealed between the segment glass 12 and the common glass 13 to be turned on and off by applying voltage between the segment electrodes 12a1,..., 12a384 and the common electrodes 13a1,. Display images by turning them on and off.

  As shown in FIG. 1A, the liquid crystal display panel of this embodiment has common transition point groups 12C1_1 and 12C_2 that are directly connected to the common electrodes 13a1,..., 13a6,. , 13 a 161, 13 a 92,..., 13 a 168 are provided on the lower side of the segment glass 12, so that wiring to the common electrodes 13 a 1,. However, not only the segment glass 12 but also a part (common wires 13b85,..., 13b161, 13b92,..., 13b168 extending from the common electrodes 13a85,... 13a161, 13a92,. Allocated. For this reason, the wiring for the common electrode on the upper side of the segment glass 12 is thick. Therefore, the phenomenon that the resistance for the common electrode on the upper side of the segment glass 12 is increased can be prevented. Image quality degradation due to uneven brightness is suppressed, and the quality of the display image is improved.

  In addition, although this embodiment demonstrated the routing to 168 common electrodes 13a1, ..., 13a168, assigning 84 pieces on the segment glass 12, and 84 pieces on the common glass 13, respectively, it is limited to this. However, the distribution of the wiring to the common electrode to the segment glass and the common glass may be arbitrary.

  The driver chip 11 in the present embodiment is a driver chip that can be freely set according to the wiring allocated to the segment glass 12 and the common glass 13. For this reason, the routing of the wiring to the common electrode is allocated to the segment glass 12 and the common glass 13 in inverse proportion to the sheet resistance value of the wiring on the segment glass 12 and the gate resistance value of the wiring on the common glass 13. be able to.

  Further, the driver chip 11 can select the output order of signals to the common electrode in an arbitrary range in ascending order / descending order. When the common electrode wiring is allocated to the segment glass 12 and the common glass 13 as in this embodiment, the common electrode wirings 12b1,..., 12b84 are in ascending order, and the common electrode wirings 12b85,. It is preferable to output in descending order.

In general, a mean square voltage is applied to the liquid crystal drive, and an error (variation) in the drive voltage is one of the major causes of display quality deterioration. Involved in this drive voltage error is the dullness of the drive voltage waveform for the common electrode. The liquid crystal of each pixel sandwiched between the segment glass and the common glass is electrically equivalent to the capacitor (C), and further considering the resistance value of the common electrode wiring (ITO resistance value R), the common electrode Rise of the drive voltage waveform (Vcom) for
Vcom = V [1-exp (−t / CR)] Equation 1
Can be expressed as Most of R in Equation 1 is due to the wiring of the output between the driver chip and the common electrode. For example, as shown in this embodiment, when the wiring routing to the common electrode is allocated in half to the segment glass and the common glass, the wiring area is secured twice as much as the wiring area of the conventional liquid crystal display panel. can do. As a result, the width of the wiring routed to the common electrode can be doubled, and the wiring resistance can be suppressed to ½.

  FIG. 3 is a diagram showing drive voltage waveforms for the common electrode in the liquid crystal display panel of the present embodiment and the conventional liquid crystal display panel.

  A graph A shown in FIG. 3 shows the drive voltage waveform (Vcom) for the common electrode calculated by the above formula 1 in the liquid crystal display panel of the present embodiment. A graph B shown in FIG. 3 shows a drive voltage waveform (Vcom) for the common electrode calculated by the above formula 1 in the conventional liquid crystal display panel. As can be seen from FIG. 3, the waveform A has a 50% improvement in the rise of the waveform (the arrival time of the voltage V at 90% of the drive voltage waveform). In addition, in order to see the influence on the liquid crystal drive voltage, considering the falling part, the root mean square voltage conversion (area conversion by integration) has improved about 26%, which has a great effect on preventing image quality deterioration. It is.

  Further, the driver chip of this embodiment can select the common drive voltage output in ascending order / descending order within an arbitrary range, and can arbitrarily set the allocation of wiring to the common electrodes on the segment glass and the common glass. Therefore, the degree of freedom in designing the segment glass and the common glass is high, and therefore the degree of freedom in designing the liquid crystal display panel is widened.

It is a top view of segment glass and common glass of a liquid crystal display panel of one embodiment of the present invention. It is the figure which expanded and showed the driver chip shown in FIG. It is a figure which shows the drive voltage waveform for common electrodes in the liquid crystal display panel of this embodiment, and the conventional liquid crystal display panel. It is a figure which simplifies and shows an example of the structure of the conventional passive matrix type liquid crystal display panel. It is a top view of the segment glass and common glass which comprise the liquid crystal display panel shown in FIG.

Explanation of symbols

10a, 10b Screen area 11 Driver chip 11a1, ..., 11a384 Segment electrode terminal 11b1, ..., 11b168 Common electrode terminal 11_1, 11_2, ..., 11_n-1, 11_n I / F terminal 12 Segment glass 12a1, ..., 12a384 Segment electrode 12B1_1, 12B1_2, 12B2_1, 12B2_2 Common electrode wiring group 12b1,..., 12b168, 13b85,..., 13b168 Common electrode wiring 12C1_1, 12C1_2, 12C2_1, 12C2_2 Glass 13a1, ..., 13a168 Common electrode 13c85, ..., 13c161, 13c92, ..., 13c168 Connection point

Claims (3)

A liquid crystal is formed between a segment substrate in which segment electrodes extending in a first direction in a predetermined screen region are arranged and a common substrate in which common electrodes extending in a second direction are arranged in a screen region overlapping the screen region. In a liquid crystal display panel that is sealed and displays an image by turning on and off the liquid crystal by turning on and off the voltage application between the segment electrode and the common electrode.
The segment substrate has a common electrode wiring connected to a common electrode on the common substrate extending on both sides of the screen region, and the common electrode wiring is connected to a terminal common substrate. The first common electrode wiring connected to the common electrode from the common transition point of the first and the second common connected to the common electrode wiring extending from the common electrode on the common substrate from the second common transition point at the end thereof A liquid crystal display panel comprising electrode wiring.   A driver chip fixed on the segment substrate and connected to the segment electrode and the common electrode and controlling voltage application between the segment electrode and the common electrode is provided, and the first common transition point is the first common transition point. 2. The liquid crystal display panel according to claim 1, wherein the liquid crystal display panel is disposed farther from the driver chip than a common transition point of two.   By the first common transition point and the second common transition point, the output signal order of the common electrode drive can be set in ascending order and descending order within an arbitrary range according to the wiring allocated on the segment substrate and the common substrate. LCD driver chip.

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