KR20080024699A - Liquid crystal display panel - Google Patents

Abstract

A liquid crystal panel is provided to improve display quality by preventing a phenomenon that stripes are recognized due to black matrixes. A first substrate(131) includes gate lines(102) to which scan signals are provided, data lines(104) crossing the gate lines, to which data voltages are applied, and subpixels defined by the gate lines and the data lines. In this case, the pixel pitch in the direction of the gate line is larger than that in the direction of the data line. The second substrate(141) includes black matrixes(106) formed to correspond to the gate lines and the data lines. Liquid crystal molecules(103) are formed between the first and second substrates and driven by an electric field between the first and second substrates. The width of the black matrixes corresponding to the gate lines is narrower than those of the black matrixes corresponding to the data lines.

Description

Liquid crystal display panel

1A and 1B illustrate a subpixel arrangement and a black matrix forming region of a conventional liquid crystal display panel in detail.

2 schematically shows a liquid crystal panel according to the present invention;

3A illustrates a subpixel and a black matrix according to the first embodiment of the present invention.

FIG. 3B is an enlarged view of the gate line shown in FIG. 3A and the horizontal line of the black matrix overlapping the gate line.

4A illustrates a subpixel and a black matrix according to a second embodiment of the present invention.

FIG. 4B is an enlarged view of the data line shown in FIG. 4A and the vertical line of the black matrix overlapping the data line.

<Explanation of symbols for the main parts of the drawings>

2, 102: gate line 4, 104: data line

6, 106: black matrix

6a, 106a; Horizontal Lines of Black Matrix

6b, 106b: vertical lines of the black matrix

The present invention relates to a liquid crystal display panel in which streaks caused by the black matrix are not visually recognized in the liquid crystal display panel. In particular, the present invention relates to a liquid crystal display panel in which black streaks due to the black matrix in the horizontal direction are prevented from being visually recognized in the liquid crystal display device in which the subpixels in the unit pixel are arranged in the vertical direction.

The liquid crystal display displays an image by adjusting the light transmittance of the liquid crystal having dielectric anisotropy using an electric field. To this end, the liquid crystal display includes a liquid crystal display panel (hereinafter referred to as a liquid crystal panel) for displaying an image through a liquid crystal cell matrix, and a driving circuit for driving the liquid crystal panel.

The liquid crystal panel is composed of a color filter panel and a thin film transistor panel bonded with liquid crystal molecules interposed therebetween.

The color filter panel includes a black filter and a color filter sequentially formed on the upper glass substrate. The black matrix is formed in the form of a matrix on the upper glass substrate so that the area of the upper glass substrate is divided into a plurality of subpixels on which a color filter is to be formed. A pixel is basically defined as a unit point constituting an image. In the liquid crystal display panel that implements color, the basic unit pixel is further divided into subpixels of three primary color pixels. The color filter is formed to be divided into red (R), green (G), and blue (B) in subpixels separated by a black matrix to form a unit pixel, and transmit red, green, and blue light, respectively.

The thin film transistor panel includes a gate line and a data line formed to cross on a lower glass substrate to define a sub pixel, and a thin film transistor and a pixel electrode formed for each sub pixel. The thin film transistor supplies the data voltage from the data line to the pixel electrode in response to the scan signal from the gate line. The pixel electrode supplies the data voltage from the thin film transistor to drive the liquid crystal molecules.

Liquid crystal molecules with dielectric anisotropy are rotated according to the data voltage of the pixel electrode and the magnitude of the electric field formed by the common voltage (Vcom) of the common electrode formed on the lower glass substrate or the upper glass substrate to realize various gray scales. do.

The subpixel arrangement of the liquid crystal panel and the black matrix forming region are described in detail with reference to FIGS. 1A and 1B. 1A and 1B illustrate a vertical field type liquid crystal panel in which a common electrode is included in a color filter panel.

1A and 1B, the thin film transistor panel includes a pixel electrode 22 in a pixel region formed in a cross structure of the gate lines 2 and the data lines 4. The pixel electrode 22 is connected to any one of the data lines 4 via the source and drain electrodes 18 and 20 of the thin film transistor 12. The gate electrode 16 of the thin film transistor 12 is connected to any one of the gate lines 2. The storage capacitor 14 is formed at an overlapping portion of the pixel electrode 22 and the previous gate line 2. Each of the data lines 4 is supplied with red, green, and blue data signals for color display.

In the color filter panel facing the thin film transistor panel and the liquid crystal molecules therebetween, a black matrix 6 is formed to divide a plurality of subpixel areas in which color filters are to be formed and to prevent light interference and external light reflection between adjacent pixels. do. To this end, the black matrix 6 is formed to correspond to the gate line 2, the data line 4, and the thin film transistor 12. The black matrix 6 is formed slightly wider than the gate line 2, the data line 4, and the thin film transistor 12 in consideration of the bonding margin between the thin film transistor panel and the color filter panel. In the subpixel divided by the black matrix 6, red (R), green (G), and blue (B) color filters are formed to correspond to a portion where the pixel electrode 22 is formed.

The shape of the unit pixel of the image representation generally has the form of a rectangle having a 4: 3 ratio of width to length. This unit pixel is further divided into R, G, and B subpixels representing three primary colors. Accordingly, each subpixel has a rectangular shape having a ratio of about 1: 3 to about 1: 5.

In general, as shown in FIG. 1A, the subpixel has a longer pixel pitch f in the data line 4 direction than the pixel pitch e in the gate line 2 direction. Pixel pitch is the distance between one side of a line adjacent to each other. In other words, the pixel pitch e in the direction of the gate line 2 is the distance between one side of an arbitrary data line 4 and one side of another neighboring data line 4. The pixel pitch f in the data line 4 direction is a distance between one side of an arbitrary gate line 2 and one side of another gate line 2 adjacent thereto. When the pixel pitch f in the direction of the data line 4 is longer than the pixel pitch e in the direction of the gate line 2, the black matrix 6 overlapping these 2 and 4 is formed by the gate line 2. Note that the vertical line 6b overlapping with the data line 4 is more prominent than the horizontal line 6a overlapping with. More specifically, the subpixel is generally formed such that the pixel pitch f in the direction of the data line 4 is about three times the pixel pitch e in the direction of the gate line 2. In addition, the wiring width f 'of the horizontal line 6a of the black matrix is formed to be substantially equal to the wiring width e' of the black matrix vertical line 6b. As a result, the ratio of the vertical lines 6b of the black matrix (hereinafter referred to as "(e '/ e)") of the pixel pitches e in the direction of the gate line 2 and the pixel pitch in the direction of the data line 4 are assumed. A relationship between Equation 1 is established between the ratio (hereinafter referred to as "(f '/ f)") of the horizontal line a of the black matrix in (f).

(e '/ e) ≒ 3 (f' / f)

Referring to Equation 1, since e '/ e is larger than f' / f, the vertical line 6b of the black matrix is more prominent in the observer's eye observing the liquid crystal panel.

As a result, when the pixel pitch f of the pixel region is longer than the pixel pitch e of the gate line 2, the vertical length of the black matrix is observed in the eyes of the observer. It can be seen that the line 6b is better recognized and there is a vertical stripe on the liquid crystal panel. However, the case illustrated in FIG. 1A is used by an observer using a conventional liquid crystal panel, and thus the vertical stripes are not recognized.

Meanwhile, as shown in FIG. 1B, a subpixel having a pixel pitch e in a direction of the gate line 2 is longer than a pixel pitch f in the direction of the data line 4 according to US Pat. No. 6,323,871. It has been proposed for the liquid crystal panel. This is proposed to reduce the number of data drive integrated circuits by 1/3 without increasing the number of gate drive integrated circuits. As such, the subpixels having a longer pixel pitch e in the direction of the gate line 2 than the pixel pitch f in the direction of the data line 4 are not familiar to the observer, so that horizontal stripes are easily recognized. In the case where the pixel region has a longer pixel pitch e in the direction of the gate line 2 than the pixel pitch f in the direction of the data line 4, the horizontal stripes are recognized by the black matrix according to the principle described above with reference to FIG. 1A. This is because the horizontal line 6a of is more prominent than the vertical line 6b of the black matrix.

As such, the conventional liquid crystal panel displays horizontal stripes or vertical stripes in accordance with the shape of the subpixel, thereby degrading display quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display panel in which streaks caused by the black matrix are prevented from being visually recognized. In particular, an object of the present invention relates to a liquid crystal display panel in which black streaks by a black matrix in a horizontal direction are prevented from being visually recognized in a liquid crystal display device in which subpixels in a unit pixel are arranged in a vertical direction.

In order to achieve the above object, the liquid crystal display panel according to the first exemplary embodiment of the present invention has a gate line to which a scan signal is supplied, an intersection of the gate line and a data line to which a data voltage is applied, and an intersection of the gate line and the data line. A first substrate comprising a subpixel defined by and having a pixel pitch greater in the gate line direction than a pixel pitch in the data line direction; A second substrate including a black matrix formed to correspond to the gate line and the data line; And liquid crystal molecules formed between the first substrate and the second substrate and driven by an electric field between the first substrate and the second substrate. The width of the black matrix corresponding to the gate line is smaller than the width of the black matrix corresponding to the data line.

The gate line is formed to a width less than one third of the data line.

The pixel pitch in the gate line direction is three times the pixel pitch in the data line direction.

The width of the black matrix for shielding the gate line is "a '", the pixel pitch in the data line direction is "a", the width of the black matrix for shielding the data line is "b'", and the gate line direction Assuming that the pixel pitch of " b " and the width formed wider on either side of the gate line and the data line in the black matrix are Y, the condition of 0 < a '/ a &lt; (b' + 4Y) / b is satisfied.

The liquid crystal display panel according to the second exemplary embodiment of the present invention is defined by a gate line to which a scan signal is supplied, a data line crossing the gate line and a data voltage applied thereto, and an intersection of the gate line and the data line. A first substrate comprising a subpixel having a larger pixel pitch in the data line direction than a pixel pitch in a direction; A second substrate including a black matrix formed to correspond to the gate line and the data line; And liquid crystal molecules formed between the first substrate and the second substrate and driven by an electric field between the first substrate and the second substrate. The width of the black matrix corresponding to the data line is smaller than the width of the black matrix corresponding to the gate line.

The data line is formed to a width less than one third of the gate line.

The pixel pitch in the data line direction is three times the pixel pitch in the gate line direction.

The width of the black matrix for shielding the data line is "c '", the pixel pitch in the gate line direction is "c", the width of the black matrix for shielding the gate line is "d'", and the data line direction When the pixel pitch is " d " and the width formed wider on one side of the gate line and the data line in the black matrix is Z, the condition of 0 < c '/ c &lt; (d' + 4Z) / d is satisfied. .

In the first and second embodiments of the present invention, the pixel pitch in the gate line direction is a distance between one side of the data line adjacent to each other, and the pixel pitch in the data line direction is a distance between one side of the gate line neighboring each other.

Other objects and advantages of the present invention other than the above object will be apparent from the description of the preferred embodiment of the present invention with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 2 to 4B.

Referring to FIG. 2, the liquid crystal panel according to the present invention includes a color filter panel 140 and a thin film transistor panel 130 facing each other with the liquid crystal molecules 103 interposed therebetween.

The thin film transistor panel 130 includes a subpixel defined by the intersection of the gate line 102 and the data line 104 on the first substrate 131, the thin film transistor 112 and the pixel electrode 122 formed for each subpixel. Equipped. The thin film transistor 112 supplies the data voltage from the data line 104 to the pixel electrode 122 in response to the scan signal from the gate line 102.

The color filter panel 140 includes a black matrix 106, a color filter 108, and a common electrode 110 sequentially formed on the second substrate 141. The black matrix 106 is formed in a matrix form on the second substrate 141. The black matrix 141 divides an area of the second substrate 141 into a plurality of subpixels in which the color filter 108 is to be formed, and prevents light interference and external light reflection between adjacent pixels. The color filter 108 is formed to be divided into red (R), green (G), and blue (B) in the subpixels separated by the black matrix 106 to form unit pixels, and the red, green, and blue light Permit each. The common electrode 110 is a transparent conductive layer coated on the color filter 108 and supplies a common voltage Vcom which is a reference when driving the liquid crystal molecules 103. In addition, an overcoat layer (not shown) may be further formed between the color filter 108 and the common electrode 110 to planarize the color filter 108.

The liquid crystal 103 having dielectric anisotropy rotates according to the magnitude of the electric field formed by the data voltage of the pixel electrode 122 and the common voltage Vcom of the common electrode 110 to adjust various light transmittances.

The liquid crystal panel further includes an alignment layer for initial alignment of the liquid crystal 103 and a spacer (not shown) for maintaining a constant cell gap between the color filter panel 140 and the thin film transistor panel 130.

A description of the liquid crystal display panel according to the present invention for preventing the display of stripes by the black matrix 106 will be described in detail with reference to FIGS. 3A to 4B.

3A is a diagram illustrating a pixel area and a black matrix according to a first embodiment of the present invention. FIG. 3B is an enlarged view of the gate line and the horizontal line of the black matrix overlapping the gate line shown in FIG. 3A.

3A and 3B, the thin film transistor panel includes a pixel electrode 122 in a subpixel having a cross structure of the gate lines 102 and the data lines 104. The subpixels of the thin film transistor panel correspond to the subpixels of the color filter panel. The pixel electrode 122 is connected to any one of the data lines 104 via the source and drain electrodes 118 and 120 of the thin film transistor 112. The gate electrode 116 of the thin film transistor 112 is connected to any one of the gate lines 102. The storage capacitor 114 is formed at an overlapping portion of the pixel electrode 122 and the previous gate line 102. Each of the data lines 104 is supplied with red, green, and blue data signals for color display.

In the color filter panel facing the thin film transistor panel and the liquid crystal molecules in between, a black matrix 106 is formed to divide a plurality of subpixels in which color filters are to be formed and to prevent light interference and external light reflection between adjacent pixels. . The black matrix 106 is formed to correspond to the gate line 102, the data line 104, and the thin film transistor 112. The black matrix 106 is formed slightly wider than the gate line 102, the data line 104, and the thin film transistor 112 in consideration of the bonding margin between the thin film transistor panel and the color filter panel. Red (R), green (G), and blue (B) color filters are formed in the subpixels separated by the black matrix 106 to form a unit pixel.

As shown in FIG. 3A, the subpixel according to the first exemplary embodiment of the present invention has a pixel pitch b in the gate line 102 direction more than a pixel pitch a in the data line 104 direction. It is formed long. Pixel pitch is the distance between one side of a line adjacent to each other. In detail, the pixel pitch b in the direction of the gate line 102 is a distance between one side of an arbitrary data line 104 and one side of another neighboring data line 104. The pixel pitch a in the data line 104 direction is a distance between one side of an arbitrary gate line 102 and one side of another neighboring gate line 102. When the pixel pitch b in the direction of the gate line 102 is longer than the pixel pitch a in the direction of the data line 104, in the first embodiment of the present invention, the gate is prevented to prevent the horizontal stripes from being recognized. The width a 'of the horizontal line 106a of the black matrix overlapping the line 102 is formed to be narrower than the width b' of the vertical line 106b of the black matrix overlapping the data line 104. For this purpose, the width of the gate line 102 should be smaller than the width of the data line 104. The width of the gate line 102 according to the present invention is generally that the pixel pitch a in the direction of the data line 104 according to the first embodiment of the present invention is about the pixel pitch b in the direction of the gate line 102. Set in consideration of the point formed 1/3 times. That is, the width of the gate line 102 is preferably formed to be 1/3 or less of the width of the data line 104. In other words, assuming that the width of the data line 104 is "X", the width of the gate line 102 is equal to or less than "X / 3" as shown in FIG. 3B. The black matrix 106 overlapping the gate line 102 and the data line 104 is formed to have a width as wide as “Y” on both sides of the gate line 102 and the data line 104 in consideration of the bonding margin. As a result, in the first embodiment of the present invention, the range of the ratio of the horizontal line 106a of the black matrix to the pixel pitch a in the direction of the data line 104 (hereinafter referred to as "(a '/ a)"). Satisfies the condition of [Equation 2].

0 <(a '/ a) ≤ (X / 3 + 2Y) / a (∵0 <a'≤X / 3 + 2Y)

= (X / 3 + 2Y) / (b / 3) (∵a = 3b)

= (((b'-2Y) / 3) + 2Y) / (b / 3) (∵b '= X + 2Y-> X = b'-2Y)

= (b '+ 4Y) / b

∴ 0 <(a '/ a) ≤ (b' + 4Y) / b

 In the first embodiment of the present invention, the a '/ a of the liquid crystal panel is formed so as to satisfy the range of Equation 2, so that the horizontal line 106a of the black matrix can be prevented from appearing. The phenomenon can be prevented.

Meanwhile, as shown in FIGS. 4A and 4B, the present invention may also be applied to a liquid crystal panel in which vertical streaks familiar to our eyes are recognized, thereby further improving display quality.

4A is a diagram illustrating a subpixel and a black matrix according to a second embodiment of the present invention. FIG. 4B is an enlarged view of the data line illustrated in FIG. 4A and the vertical line of the black matrix overlapping the data line.

4A and 4B, the subpixels of the liquid crystal panel according to the second embodiment of the present invention have a data line larger than the pixel pitch c in the direction of the gate line 102 as compared with the first embodiment of the present invention. The difference is that the pixel pitch d in the (104) direction is formed longer.

In the case where the pixel pitch d in the direction of the data line 104 is longer than the pixel pitch c in the direction of the gate line 102, in the second embodiment of the present invention, data is prevented to prevent the vertical stripes from being recognized. The width c ′ of the vertical line 106b of the black matrix overlapping the line 104 is formed to be narrower than the width d ′ of the horizontal line 106a of the black matrix overlapping the gate line 102. For this purpose, the width of the data line 104 should be smaller than the width of the gate line 102. The width of the data line 104 according to the present invention is generally such that the pixel pitch c in the direction of the gate line 102 according to the second embodiment of the present invention is about the pixel pitch d in the direction of the data line 104. Set in consideration of the point formed 1/3 times. That is, the width of the data line 104 is preferably formed to be 1/3 or less of the width of the gate line 102. In other words, assuming that the width of the gate line 102 is "Z", the width of the data line 104 is equal to or less than "Z / 3" as shown in FIG. 4B. The black matrix 106 overlapping the data line 104 and the gate line 102 is formed to have a width as wide as "W" on both sides of the data line 104 and the gate line 102 in consideration of the bonding margin. As a result, in the second embodiment of the present invention, the range of the ratio of the vertical line 106b of the black matrix to the pixel pitch c in the direction of the gate line 102 (hereinafter, referred to as "(c '/ c)"). Satisfies the condition of [Equation 3].

0 <(c '/ c) ≤ (Z / 3 + 2W) / c (∵0 <c'≤Z / 3 + 2W)

= (Z / 3 + 2W) / (d / 3) (∵c = 3d)

= (((d'-2W) / 3) + 2W) / (d / 3) (∵d '= Z + 2W-> Z = d'-2W)

= (d '+ 4W) / d

∴ 0 <(c '/ c) ≤ (d' + 4W) / d

 According to the second embodiment of the present invention, the c '/ c of the liquid crystal panel is formed to satisfy the range of Equation 3, so that the vertical line 106b of the black matrix can be prevented from appearing so that vertical stripes are observed in the observer's eyes. The perceived phenomenon can be prevented.

In the above-described embodiment of the present invention, the vertical field application type liquid crystal panel has been described mainly, but the present invention can be applied without being limited to the liquid crystal panel of a specific mode.

As described above, in the liquid crystal panel according to the present invention, the black matrix of a specific line is prominent by forming a black matrix width in a direction parallel to a pixel pitch formed relatively narrowly in a subpixel than a black matrix width crossing the pixel matrix. To prevent. Since the width of the black matrix according to the present invention is determined by the width of the signal line, in the embodiment of the present invention, a signal line in a direction parallel to the pixel pitch direction, which is formed relatively narrow in the pixel area, is formed to be narrower than a signal line crossing the same. This prevents streaks from being recognized by the black matrix. Accordingly, the liquid crystal display panel according to the present invention improves display quality by preventing the phenomenon of streaks being recognized.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (10)

A pixel pitch in the gate line direction is defined by a gate line to which a scan signal is supplied, a data line that crosses the gate line and a data voltage is applied, and an intersection of the gate line and the data line. A first substrate comprising a larger formed subpixel; A second substrate including a black matrix formed to correspond to the gate line and the data line; A liquid crystal molecule formed between the first substrate and the second substrate and driven by an electric field between the first substrate and the second substrate, The width of the black matrix corresponding to the gate line is smaller than the width of the black matrix corresponding to the data line. The method of claim 1, And the gate line has a width less than 1/3 of the data line. The method of claim 2, And the pixel pitch in the gate line direction is three times the pixel pitch in the data line direction. The method of claim 2, The width of the black matrix for shielding the gate line is "a '", the pixel pitch in the data line direction is "a", the width of the black matrix for shielding the data line is "b'", and the gate line direction When the pixel pitch of "b" is Y, the width formed wider on one side of the gate line and the data line in the black matrix is Y. A liquid crystal display panel satisfying a condition of 0 <a '/ a ≤ (b' + 4Y) / b. The method of claim 1, The pixel pitch in the gate line direction is a distance between one side of the data line adjacent to each other, And the pixel pitch in the data line direction is a distance between one side of the gate line adjacent to each other. A pixel pitch in the data line direction is defined by a gate line to which a scan signal is supplied, a data line that crosses the gate line and a data voltage is applied, and an intersection of the gate line and the data line. A first substrate comprising a larger formed subpixel; A second substrate including a black matrix formed to correspond to the gate line and the data line; A liquid crystal molecule formed between the first substrate and the second substrate and driven by an electric field between the first substrate and the second substrate, The width of the black matrix corresponding to the data line is smaller than the width of the black matrix corresponding to the gate line. The method of claim 6, And the data line has a width less than 1/3 of the gate line. The method of claim 7, wherein And the pixel pitch in the data line direction is three times the pixel pitch in the gate line direction. The method of claim 7, wherein The width of the black matrix for shielding the data line is "c '", the pixel pitch in the gate line direction is "c", the width of the black matrix for shielding the gate line is "d'", and the data line direction When the pixel pitch of "d" and the width formed wider on one side of the gate line and the data line of the black matrix are Z, A liquid crystal display panel satisfying the condition of 0 <c '/ c ≤ (d' + 4Z) / d. The method of claim 6, The pixel pitch in the gate line direction is a distance between one side of the data line adjacent to each other, And the pixel pitch in the data line direction is a distance between one side of the gate line adjacent to each other.

Images