KR101066498B1 - In-Plane Switching Mode Liquid Crystal Display Device - Google Patents

Abstract

The present invention relates to a transverse electric field type liquid crystal display device configured to compensate and apply a common voltage for each region. The transverse field type liquid crystal display device according to the present invention defines a display area and a non-display area around it, and is formed to face each other. A gate line and a common line formed alternately with each other in a direction parallel to each other on a first substrate and a second substrate, the display area on the first substrate, and a pixel area intersecting the gate line on the display area on the first substrate; A data line to be defined and connected to the common lines in the non-display area, and formed in a direction perpendicular to the common line, divided into a plurality of areas, and a common voltage signal is applied to each other. A vertical common line formed to have a thinner width than a portion, a driving signal applied to the data line, and the respective zeros; A source PCB having a plurality of common voltage compensators for calculating a compensation common voltage signal applied to the vertical common line, a common electrode and a pixel electrode alternately formed in the pixel region, and between the first substrate and the second substrate. Characterized in that it comprises a liquid crystal layer filled in.

Common electrode, common line, common electrode compensation, compensation circuitry

Description

In-Plane Switching Mode Liquid Crystal Display Device

1 is a plan view showing a typical transverse electric field type liquid crystal display device

2 is a schematic diagram showing application of a common voltage of a general transverse electric field type liquid crystal display device;

Fig. 3 is a schematic diagram showing application of a common voltage of a LOG type transverse electric field liquid crystal display device;

4 is a circuit diagram illustrating a compensation circuit used in FIG. 3.

5 is a schematic diagram showing a common voltage applied to the transverse electric field type liquid crystal display device of the present invention.

FIG. 6 is an enlarged view illustrating an intersection of group A and group B of FIG. 5;

7 is a view illustrating a signal line applying side in FIG. 6;

8A and 8B are circuit diagrams illustrating a first compensator and a second compensator of a transverse electric field type liquid crystal display of the present invention.

* Description of Symbols Representing Major Parts of Drawings *

100: substrate 101: gate line

102: data line 105, 106: vertical common line

111: first TCP 112: gate drive IC

121: second TCP 122: data drive IC

130: source PCB 131: common voltage forming unit

132: first compensation unit 133: second compensation unit

134: third compensation unit 135: fourth compensation unit

150: display area

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a transverse electric field type liquid crystal display device configured to compensate and apply a common voltage for each region.

(PDP), Electro Luminescent Display (ELD), Vacuum Fluorescent (VFD), and the like have been developed in recent years in response to the demand for display devices. Display) have been studied, and some of them have already been used as display devices in various devices.

Among them, LCD is the most widely used as the substitute for CRT (Cathode Ray Tube) for mobile image display device because of its excellent image quality, light weight, thinness, and low power consumption. In addition to the use of the present invention has been developed in various ways such as a television and a computer monitor for receiving and displaying broadcast signals.

In order to use such a liquid crystal display as a general screen display device in various parts, it is a matter of how high quality images such as high definition, high brightness and large area can be realized while maintaining the characteristics of light weight, thinness and low power consumption. Can be.

A liquid crystal display device driven by a vertical electric field is generally called a twisted nematic (TN) mode liquid crystal display device, and the TN mode liquid crystal display device has a disadvantage in that the viewing angle is narrow. (IPS: In-Plane Switching) mode A liquid crystal display device has been developed.

In a transverse electric field type (IPS) mode liquid crystal display, a pixel electrode and a common electrode are formed parallel to each other at a predetermined distance in a pixel area of a first substrate so that a transverse electric field (horizontal electric field) is generated between the pixel electrode and the common electrode. The liquid crystal layer is oriented by the lateral electric field.

Hereinafter, a conventional transverse electric field type liquid crystal display device will be described with reference to the accompanying drawings.

1 is a plan view illustrating a general transverse electric field type liquid crystal display device.

As shown in FIG. 1, in a typical transverse electric field type liquid crystal display device, a gate line 31 and a data line 32 are arranged perpendicularly to each other to define a pixel area on a first substrate (see 30 of FIG. 2). The thin film transistor TFT is formed at a portion where the gate line 31 and the data line 32 cross each other, and the pixel electrode 33 and the common electrode 35a are alternately formed in each pixel area.

The thin film transistor TFT may include a gate electrode 31a protruding from the gate line 31, a source electrode 32a protruding from the data line 32, and a drain electrode 32b spaced from the gate electrode 31a. It is done by The semiconductor layer 34 is further formed on the lower layer of the source electrode 32a / drain electrode 32b to cover the gate electrode 31a.

The common electrode 35a is formed to branch from a common line 35 parallel to the gate line 31, and the common line 35 is formed to overlap the pixel electrode 33. Voltage is applied to the common electrode 35a and the pixel electrode 33, respectively, and a transverse electric field is formed between the two electrodes, thereby driving the liquid crystal.

Meanwhile, a non-pixel region (gate line 31, data line 32, and thin film transistor (TFT) region) excluding the pixel region is covered on a second substrate (not shown) facing the first substrate 30. And a color filter layer (not shown) and the color filter layer formed on the second substrate including the black matrix layer (not shown), the R, G, and B pigments corresponding to each pixel region in turn. An overcoat layer (not shown) formed on the front surface of the second substrate is formed.

2 is a schematic diagram illustrating application of a common voltage of a general transverse electric field type liquid crystal display device.

As illustrated in FIG. 2, in a general transverse electric field type liquid crystal display, common lines 35 are formed adjacent to each of a plurality of gate lines 31 in the same direction (the horizontal direction on the drawing). In this case, the gate signal applied to the gate line 31 and the common voltage signal Vcom applied to the common line 35 may be supplied together by a gate driver (not shown) that supplies the gate signal. At this time, if n gate lines 31 are formed, a thin film transistor array is formed on the display region 20 (the region shown by the dotted line and the region where the actual display is made), and the outside of the display region. The same n common lines 35 are formed in the pad portion for applying a signal to the.

Here, the common vertical lines 25 and 26 are left and right of the display area 20, and the common lines 35 are formed in the horizontal direction to apply the common voltage signal Vcom to the common electrode in the display area 20. Are connected in a vertical direction.

Reference numeral 31a, which is not described, indicates a gate pad formed on the first substrate 30, and gate signals Gate1, Gate2, ..., and Gate n are sequentially applied from an external driver, respectively.

23, 24, 27, and 28 are lines to which a common voltage signal is applied by connecting the common vertical lines 25 and 26 to an external driving unit.

FIG. 3 is a schematic diagram illustrating application of a common voltage of a LOG type transverse electric field type liquid crystal display device, and FIG. 4 is a circuit diagram illustrating a compensation circuit used in FIG. 3.

Vcomf/b)한다.In the LOG (Lin On Glass) type, the gate PCB (Printed Circuit Board) is embedded on the first substrate 10, the wiring from the source PCB (not shown) to the gate drive IC 41 is the first It is embedded on the substrate 10 and formed. In the LOG type, since the gate PCB is omitted, the gate signal is supplied from the source PCB to each gate drive IC through the LOG wiring formed on the first substrate 10 and sequentially supplied to each gate line. In addition, the source PCB further includes a common voltage compensator and a common voltage compensating circuit separate from each other, such that the common voltage signals L Vcomc and R Vcomc formed in the compensating circuit form a separate LOG wiring on the first substrate 30. Through the vertical common lines 25 and 26 formed in the left and right regions of the display area, respectively. In this case, the common voltage compensating circuit receives a Vcom signal from the common voltage generator and compensates for the difference in common voltage between the first common line and the nth common lines that are first supplied, and applies the Vcom signal to the nth common line. The feedback signals L Vcom f / b and R Vcom f / b are supplied from the vertical common lines 25 and 26 of the corresponding portions and input as the input signals, and have a predetermined amplification ratio (-R2 / R1). Output the compensation common voltages L Vcomc and R Vcomc through compensation circuits 80, 81, and 82 as shown in (Vcomc = (-)).

Vcomf / b).

However, the conventional transverse electric field type liquid crystal display device has the following problems.

As shown in FIG. 4, when the feedback signals L Vcomf / b and R Vcomf / b of the common voltage are subtracted from the final stage, the compensation of the common voltage in the A region will be less. On the contrary, the common voltage at the end of the A region will be reduced. Subtracting the feedback signal of will reduce the compensation of the B area. As such, even when the compensation circuit is provided, a problem occurs in that a specific area is less compensated.

An object of the present invention is to provide a transverse electric field type liquid crystal display device which is designed to solve the above problems and to compensate and apply a common voltage for each region.

In the transverse electric field type liquid crystal display device of the present invention for achieving the above object, a display area and a non-display area around the first area, the first substrate and the second substrate formed to face each other, and the display on the first substrate A gate line and a common line formed alternately in a direction parallel to each other in a region, a data line defining a pixel region crossing the gate line in a display region on the first substrate, and the common lines in the non-display region A common common signal formed in a direction perpendicular to the common line, divided into a plurality of regions, and having a common voltage signal applied thereto, and having a thinner width between the regions and the regions than the other portions; Compute a driving signal applied to a data line and a compensation common voltage signal applied to the vertical common line for each region. In the yirueojim comprising a plurality of common voltage compensation a source PCB, and a common electrode formed to one another alternately in the pixel region and the pixel electrode and a liquid crystal layer filled between the first substrate and the second substrate comprising a has its features.

The source PCB includes a common voltage forming unit, and a common voltage output from the common voltage forming unit is applied to each common voltage compensating unit.

The common electrode and the common line are electrically connected to each other.

Hereinafter, the transverse electric field type liquid crystal display of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 5 is a schematic diagram illustrating a common voltage application of the transverse electric field type liquid crystal display of the present invention, FIG. 6 is an enlarged view of an intersection of the group A and the group B of FIG. 5, and FIG. It is a diagram showing.

5 to 7, in the transverse electric field type liquid crystal display according to the present invention, the first substrate 100 and the second substrate (not shown) in which the display area 150 and the non-display area around it are defined and formed to face each other. A gate line 101 and a common line 103 alternately formed in the display area on the first substrate 100 in a direction parallel to each other, and the gate line in the display area on the first substrate 100. A data line 102 crossing the 101 to define a pixel area, and connected to the common lines 103 in the non-display area, and formed in a direction perpendicular to the common line 103, and a plurality of areas The common voltage signal is divided into two groups, and the vertical common lines 105 and 106 are formed to have thinner widths between the regions and the regions, and the driving signals applied to the data lines 102 and the The vertical common line for each region A source PCB 130 having a plurality of (common voltage) compensation units 132, 133, 134, and 135 for calculating an applied compensation common voltage signal, and a common electrode (not shown) alternately formed in the pixel area. And a liquid crystal layer (not shown) filled between the pixel electrode (not shown) and the first substrate 100 and the second substrate (not shown). Here, the common electrode and the common line are electrically connected to each other.

In FIG. 5, the source PCB 130 is provided with a common voltage forming unit 131, and the common voltage Vcom output from the common voltage forming unit 131 is the first to fourth compensating unit 132. 133, 134, 135, respectively. Each compensator includes the common voltage Vcom and the first to fourth feedback common voltages Vcomfb1, Vcomfb2, Vcomfb3, and Vcomfb4 output from the respective regions (Group A and Group B), respectively, as input signals. The first to fourth common voltages Vcom1, Vcomc2, Vcom3, and Vcom4 calculated by the compensation circuit included in the compensator are applied to the common voltage of the corresponding region (Group A, Group B).

In the drawing, a region is formed by dividing the region into two regions, but in some cases, it may be considered to divide the region into two or more regions and apply a corresponding compensation common voltage for each region.

In this case, in the transverse electric field type liquid crystal display device of the present invention, as shown in Figs. 6 and 7, the vertical common lines 105 and 106 are placed between the respective regions and the regions of the vertical common lines 105 and 106. By forming a thinner than the wiring width, it is possible to prevent the division of time between the regions caused by the difference of the compensation common voltages Vcom1, Vcom2, Vcom3, and Vcom4 that are compensated differently between the two regions.

In this case, the compensated first compensation common voltage Vcom1 is applied to a portion of the vertical common line 105 connected to the first common line side of the vertical common line 105 of the region A, and the vertical common common region 105 of the region A is applied. The first feedback common voltage signal Vcomfb1 is output from the vertical common line 105 portion connected to the common line side of the end of the line 105 to the input of the first compensator 132 of the source PCB 130. Is approved.

Similarly, the compensated second compensation common voltage Vcom2 is applied to a portion of the vertical common line 105 connected to the first common line side of the vertical common line 105 of the region B, and the vertical common line of the region B is vertical. The second feedback common voltage signal Vcomfb2 is output from the vertical common line 105 portion connected to the common line side of the termination of the 105 and applied to the input of the second compensator 133 of the source PCB 130. do.

Although not shown, the same structure may be considered for the vertical common line formed on the right side of the display area 150.

8A and 8B are circuit diagrams illustrating a first compensator and a second compensator of a transverse electric field type liquid crystal display of the present invention.

8A and 8B illustrate internal circuit configurations of the first compensator 132 and the second compensator 133, and according to the values of the feedback common voltage signals Vcomfb1 and Vcomfb2, the amplification ratio (-R2). / R1, -R4 / R3) will be configured differently.

Vcomf/b1)이 출력된다.In this case, the component circuit of the first compensator 132 may include an operational amplifier OP, an inverting (−) input terminal of the operational amplifier OP, and a fed back common voltage input terminal of the first region (Group A); And a first resistor R1 formed therebetween, and a second resistor R2 connected between the inverting (−) input terminal and the output terminal of the operational amplification OP. A common voltage is applied to the non-inverting (+) input terminal of OP), and the operational amplifier OP is driven by applying a power supply voltage Vdd. Through the first compensation unit 132, a first compensation common voltage Vcom1 = (−)

Vcomf / b1) is output.

Similarly, the second to fourth compensation units 133 to 135 output corresponding compensation common voltages by varying the amplification ratios by changing the values of the first and second resistors.

The above-described transverse electric field type liquid crystal display of the present invention has the following effects.

The panel is divided into a plurality of regions, and a plurality of compensation circuits are configured for each region, and a common voltage feedback signal is output from the vertical common line portion on the common line side corresponding to the end of each region, and the common voltage feedback signal is output to the compensation circuit. The power supply is compensated for the common voltage to apply the compensated common voltage value for each region. In this case, in order to prevent images being separated and observed for each region, a pattern of vertical common lines between the regions is formed to be thinner than the pattern of vertical common lines of other portions to prevent separation of images for each region. Therefore, by applying a compensated value suitable for the region of the common voltage value, thereby preventing problems such as crosstalk, thereby preventing afterimages and the like and improving visibility.

Claims (3)

A first substrate and a second substrate defined by the display area and a non-display area around the display area and formed to face each other; A gate line and a common line that are alternately formed in the display area on the first substrate in a direction parallel to each other; A data line defining a pixel area in the display area on the first substrate to cross the gate line; The common line is connected to the common lines in the non-display area, and is formed in a direction perpendicular to the common line. The common voltage signal is divided into a plurality of areas, and the width between each area and the area is thinner than that of other areas. A vertical common line formed to have; A source PCB having a plurality of common voltage compensators configured to calculate a driving signal applied to the data line and a compensation common voltage signal applied to the vertical common line for each region; A common electrode and a pixel electrode which are alternately formed in the pixel region; And And a liquid crystal layer filled between the first substrate and the second substrate. The method of claim 1, The source PCB includes a common voltage forming unit, and the common voltage output from the common voltage forming unit is applied to each common voltage compensating unit. The method of claim 1, And the common electrode and the common line are electrically connected to each other.

Images