KR20070078885A - Liquid crystal display panel and bidirectional liquid crystal display including the same - Google Patents

Abstract

The present invention relates to a bidirectional liquid crystal display panel and a bidirectional liquid crystal display including the same. According to the present invention, a transmissive polarizer is used in the main screen area and a reflective polarizer is used in the sub screen area. Thus, the entire thin film transistor substrate and the color filter substrate are manufactured in a transmissive type to increase light transmittance, thereby improving overall optical characteristics of the liquid crystal display panel. Can be. In addition, since the present invention manufactures the entire area of the color filter substrate in a transmissive type, the manufacturing process is easy and the number of processes is reduced, thereby minimizing the cost burden. In addition, the present invention can provide a liquid crystal display device in which the light guide plate is formed not only in the main screen area but also in the sub screen area so that the sub screen area is easily seen even in the dark.

Description

Liquid crystal display panel and bidirectional liquid crystal display including the same {LIQUID CRYSTAL PANEL AND TWO-WAY LIQUID CRYSTAL DISPLAY USING THE SAME}

1 is an exploded perspective view of a double-sided liquid crystal display panel according to the present invention.

2 is a plan view for explaining a double-sided liquid crystal display panel according to the present invention.

3 is an enlarged conceptual view illustrating region C of FIG. 2.

4 is an exploded perspective view of a double-sided liquid crystal display according to a first embodiment of the present invention.

FIG. 5 is a sectional view taken on line A-A in FIG. 4; FIG.

6 is an exploded perspective view of a double-sided liquid crystal display according to a second embodiment of the present invention.

FIG. 7 is a sectional view taken on line B-B in FIG. 6; FIG.

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

100 liquid crystal display panel 110 thin film transistor substrate

120: color filler substrate 130: drive IC

210: light source 220: light guide plate

230: reflector 240: optical sheet

200: backlight 500a: first polarizing plate

500b: second polarizing plate 400: third polarizing plate

The present invention relates to a bidirectional liquid crystal display panel and a bidirectional liquid crystal display device including the same, and more particularly, to a bidirectional liquid crystal display panel using a transmissive polarizing plate and a reflective polarizing plate, and a bidirectional liquid crystal display including the same.

A double-sided liquid crystal display device that can view images on both sides has recently been applied to a foldable portable wireless terminal so that information can be displayed regardless of whether the folder is closed or opened.

In the conventional double-sided liquid crystal display device, a liquid crystal display panel including a main screen area displaying an image in one direction and a sub screen area displaying an image in the other direction, and a backlight for supplying light to the liquid crystal display panel. It includes. In this case, the liquid crystal display panel includes a thin film transistor and a color filter substrate, and polarizers attached to both surfaces of the two substrates.

The double-sided liquid crystal display device according to the related art having the above structure manufactures a color filter substrate and a polarizer attached to the color filter substrate in a semi-transmissive manner to drive the main screen and the sub screen with one panel.

Therefore, irrationality of applying the transflective liquid crystal and the polarizing plate also occurs in the main screen area forming the transmissive mode screen, and the cost burden increases due to the increase in the number of processes by performing the transflective process on the color filter substrate in the sub screen area. There is this.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems of the prior art, and to provide a bidirectional liquid crystal display panel including a main screen region and a sub screen region of a liquid crystal display panel formed in a transmissive type and a bidirectional liquid crystal display device including the same.

Another object of the present invention is to provide a bidirectional liquid crystal display panel having a sub display area visible in a dark place and a bidirectional liquid crystal display device including the same.

In order to achieve the above object, the present invention provides a liquid crystal display panel including a thin film transistor substrate and a color filter substrate in which a first display region and a second display region are defined. A liquid crystal display panel comprising a first polarizing plate provided in a display area and a second polarizing plate provided in the second display area.

In this case, the first polarizing plate may be a transmission type, and the second polarizing plate may be a reflection type.

The color filter substrate may be a transmissive type, and the second display area may be a sub screen display area.

In the first display area of the color filter substrate, each single pixel may include red, green, and blue subpixels.

The second display area of the color filter substrate may include any one of red, green, and blue subpixels in a single pixel.

Furthermore, the present invention is a liquid crystal display panel including a thin film transistor substrate and a color filter substrate in which a first display region and a second display region are defined, the first display region being provided on one surface of the color filter substrate and provided in the first display region. A liquid crystal display panel comprising a polarizing plate and a second polarizing plate provided in the second display area and a reflective polarizing plate, and a backlight unit for supplying light to the liquid crystal display panel may be provided. .

In this case, the backlight unit may include a light guide plate and a light source, and the light guide plate may be provided in the first display area under the liquid crystal display panel.

The backlight unit may include a light guide plate and a light source, and the light guide plate may be provided in the first and second display areas under the liquid crystal display panel.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in more detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you.

In the drawings, the thickness of layers, films, panels, regions, etc., may be exaggerated for clarity, and like reference numerals designate like elements. In addition, when a part such as a layer, a film, an area, or a plate is expressed as being on or above another part, not only when each part is directly above or directly above the other part but also another part between each part and another part This includes cases.

1 is an exploded perspective view of a double-sided liquid crystal display panel according to the present invention, FIG. 2 is a plan view illustrating a liquid crystal display panel according to the present invention, and FIG. 3 is an enlarged conceptual view of region C of FIG. 2.

1 to 3, a double-sided liquid crystal display panel according to an exemplary embodiment of the present invention includes a thin film transistor substrate 110 and a color filter substrate having a main display area A as a main display and a section display area B as a sub display. 120). In this case, the thin film transistor substrate 110 and the color filter substrate 120 includes polarizers 400 and 500 provided on both surfaces thereof. In addition, the liquid crystal layer (not shown) is provided between the thin film transistor substrate 110 and the color filter substrate 120.

The thin film transistor substrate 110 may include a plurality of pixel regions in a matrix form, and may be a light-transmissive insulating substrate including a thin film transistor and a pixel electrode provided in the pixel region. At this time, it is effective to use a rectangular glass substrate as shown in the figure as the insulating substrate for forming the thin film transistor and the pixel electrode.

The source terminal of the thin film transistors is connected to a data line extending in one direction, and the gate terminal is connected to a gate line extending in another direction perpendicular to the one direction. The drain terminal is connected to a pixel electrode made of a transparent conductive material provided in a part of the pixel region. In this case, it is preferable to use indium tin oxide (ITO) or indium zinc oxide (IZO) as the transparent conductive material.

When the thin film transistor substrate 110 applies an electrical signal to the gate line and the data line, the thin film transistor is turned on or turned off, and thus the thin film transistor substrate 110 is applied to the electrical signal of the data line, that is, the pixel formation. The necessary electrical signal is applied to the pixel electrode.

To this end, it further includes a separate driver 130 for driving the gate line and the data line. In this case, the liquid crystal display panel according to the present invention has a structure in which the gate driver 130 for gate driving of the thin film transistor is mounted on one end of the thin film transistor substrate 110 in an IC form as connected to the gate line. Have Of course, the gate line driver 130 is driven by a control signal of an external system. The data driver, which is not shown, may be mounted on a separate flexible circuit board and connected to the data line of the thin film transistor.

The color filter substrate 120 is a pixel region corresponding to the thin film transistor substrate 110 and is preferably a translucent insulating substrate including a color filter and a common electrode provided in the pixel region.

The color filter and the common electrode may be disposed in a plurality of pixel areas corresponding to the pixel electrode, and the common electrode may be disposed on the entire surface of the color filter substrate 120. In addition, the color filter substrate 120 is preferably provided with a black matrix pattern for preventing light leakage. Here, the common voltage Vcom is applied to the common electrode.

Meanwhile, the above-described thin film transistor substrate 110 and the color filter substrate 120 are pressed by pressing the two substrates such that each pixel electrode and the common electrode face each other. In this case, a predetermined sealing film may be applied to seal the two substrates. In addition, a spacer may be provided to maintain a cell gap between the two substrates. Thereafter, a liquid crystal is injected and sealed between the two bonded substrates through liquid crystal injection to manufacture a liquid crystal display panel. Although liquid crystal injection was performed in the above, a liquid crystal may be dripped before bonding of two board | substrates.

The liquid crystal display panel manufactured as described above may turn on the thin film transistor of the thin film transistor substrate 110 to apply an electrical signal necessary for pixel formation to the pixel electrode, and apply a common voltage to the common electrode of the color filter substrate 120. An electric field is formed between the pixel electrode and the common electrode. Such an electric field causes the arrangement of the liquid crystal layer to change, and the light transmittance is changed according to the changed arrangement to display a target image.

In this case, as described above, the liquid crystal display panel according to the present invention is defined as a main display area A for displaying an image on one side and a section display area B for displaying an image on the other side. In other words, a single panel displays images on different sides. For example, the main display area A may display an image in a plane in the direction of the color filter substrate 120, and the section display area B may display an image in a plane in the direction of the thin film transistor substrate 110. . In addition, fabrication of the unit pixels of the two display regions may be formed differently according to characteristics of the display region.

The liquid crystal display panel is preferably manufactured in a transmissive type to increase optical characteristics and luminance. However, in the liquid crystal display panel according to the prior art, the entire liquid crystal display panel is manufactured in a transflective type to drive the section display area, and the section display area B of the color filter substrate is manufactured in a color filter on reflector (COR) structure. . However, the liquid crystal display panel according to the present invention intends to manufacture the entire liquid crystal display panel in a transmissive type using a polarizing plate attached to both surfaces of the liquid crystal display panel different from the conventional structure.

The polarizers 400 and 500 include first and second polarizers 500a and 500b provided on an upper surface of the liquid crystal display panel and a third polarizer 400 provided on a lower surface thereof. In this case, the first polarizing plate 500a is provided on the main display area A, and the second polarizing plate 500b is provided in the section display area B. FIG. In addition, the third polarizer 400 is provided in the entire main display area A and the section display area B. FIG.

Meanwhile, in the conventional bidirectional liquid crystal display, the polarizers 400 and 500 generally use a transflective polarizer, but the present invention uses a transmissive polarizer and a reflective polarizer. That is, the third polarizing plate 400 and the first polarizing plate 500a provided in the main display area A use a transmissive polarizing plate, and the second polarizing plate 500b provided in the section display area B uses a reflective polarizing plate. use. Therefore, the light transmittance of the main display area A of the liquid crystal display panel is higher than that of using a transflective polarizing plate, and thus the overall optical characteristic is increased. In addition, the section display area B uses the reflective polarizing plate as the second polarizing plate 500b and the color filter substrate 120 as the transmissive type to increase the transmittance, thereby maximizing the amount of light so that the section of the section display area B is increased. The light is reflected by the polarizer 500b.

In addition, the process of the color filter substrate according to the related art requires a reflective layer to be formed in the section display area B, but the present invention is complicated. However, the present invention uses the section display area B of the color filter substrate 120 as the main display area A. FIG. In other words, fabrication of the entire area of the color filter substrate 120 may be performed in a transmissive manner, and thus, the manufacturing process may be easier and the number of processes may be reduced, thereby minimizing the cost burden.

Meanwhile, although FIG. 2 illustrates that the section display area B is located at the upper one side edge area of the liquid crystal display panel 100 with the same width as the main display area A, the present invention is not limited thereto. The region B may be formed in any region of the liquid crystal display panel 100. Further, the width of the main display area A may be smaller than that of the main display area A. FIG. As shown in the drawing, an area on which the gate driver 130 is mounted is preferably provided at one side of the liquid crystal display panel.

Meanwhile, the main display area A and the section display area B may display different images by receiving driving voltages through different driving units, and may display the same image by inverting them. Alternatively, different operations may be displayed on the main display area A and the section display area B by separating the operation in the drive unit through the single drive unit. The main display area A preferably displays images of various data values, and the section display area B preferably displays images of a single data value. That is, when the liquid crystal display panel defined as described above is applied to a portable terminal (for example, a dual-type foldable cellular phone), the section display area B is a date, time, antenna, battery state, etc. in the portable terminal. It is desirable to display simple data of. Thus, as shown in FIG. 3, the main display area A may be manufactured in a structure having three subpixels emitting R, G, and B colors in a single pixel, thereby displaying an image of a total color. As shown in the drawing, the section display area B is fabricated in a structure in which a single pixel emits one of R, G, and B colors. As a result, an image of the same color may be displayed in the predetermined area. It is preferable to display an image using a single color since only the image corresponding to the same data value is always displayed in the section display area B. FIG. Furthermore, since one large pixel is used in the unit pixel, the design of the section display area B can be simplified, the signal line can be reduced, and the aperture ratio can be improved.

Of course, the present invention is not limited thereto, and the present invention may be manufactured in a structure having three subpixels emitting R, G, and B colors in the unit pixels of the section display area B. FIG.

Next, a liquid crystal display including a liquid crystal display panel according to the present invention will be described with reference to the drawings. Descriptions overlapping with the description of the liquid crystal display panel described above will be omitted.

4 is an exploded perspective view of a double-sided liquid crystal display according to the present invention, and FIG. 5 is a cross-sectional view taken along line B-B of FIG. 3.

4 and 5, a double-sided liquid crystal display according to the present invention includes a liquid crystal display panel 100 having a main display area A and a section display area B, and both sides of the liquid crystal display panel 100. Polarizing plates 400 and 500 provided in the backlight unit and a backlight unit 200 for irradiating light to the main display area A. The liquid crystal display panel 100 may further include a mold frame 600 for fixing the backlight unit 200 and an accommodating member 700 for accommodating the liquid crystal display panel 100.

The liquid crystal display panel 100 includes a thin film transistor substrate 110 and a color filler substrate 120. In this case, the thin film transistor substrate is a transparent glass substrate in which a thin film transistor (TFT) and a pixel electrode are formed in a matrix form, and the color filter substrate 120 is a color in which a predetermined color is expressed while light passes. An RGB pixel that is a pixel is a substrate formed by a thin film process. In the present invention, the thin film transistor substrate 110 and the color filter substrate 120 are manufactured in a transmission type.

The backlight unit 200 is to supply light to the main display area A of the liquid crystal display panel 100, and is provided on a portion of the lower side of the liquid crystal display panel 100. In this case, the backlight unit 200 includes a light source 210, a light guide plate 220 for irradiating light from the light source 210 to the main display area A of the liquid crystal display panel 100, and the light guide plate 220. A plurality of optical sheets 240 provided on the upper, and the reflecting plate 230 provided below the light guide plate 220.

It is preferable to use a white LED lamp as the light source 210. And, although not shown in the figure, such LED lamps are preferably mounted on a flexible circuit board. The light source 210 may be disposed on any surface of the main display area A of the liquid crystal display panel 100, but preferably, the light source 210 is disposed at an edge area facing the section display area B. At least one white LED lamp may be used, but the white LED lamps may be spaced at uniform intervals to supply uniform white light to the entire light guide plate.

The light guide plate 220 is disposed adjacent to the light source 210 to change light having an optical distribution in the form of a line light source generated by the light source 210 to light having an optical distribution in the form of a surface light source. As the light guide plate 220, a wedge type plate or a parallel flat plate may be used. In addition, the light guide plate 220 is generally formed of high polymethylmethacrylate (PMMA) having high strength and not easily being deformed or broken. The light guide plate 220 is provided under the main display area A of the liquid crystal display panel 100.

The reflective plate 230 is provided below the light guide plate 220. At this time, the reflective plate 230 serves to reduce the light loss by re-reflecting the light incident on the light guide plate 220 through the back of the light guide plate 220 using a plate having a high light reflectance.

The plurality of optical sheets 240 include a diffusion sheet, a brightness enhancing sheet, and a polarizing sheet, which are disposed between the light guide plate 220 and the main display area A of the liquid crystal display panel 100 and exit from the light guide plate 220. The luminance distribution of the received light is made uniform and irradiated to the main display area A. FIG. The diffusion sheet directs the light incident from the light guide plate 220 toward the front of the liquid crystal display panel 100 and diffuses the light to have a uniform distribution in a wide range so that the liquid crystal display panel 100 is irradiated. As the diffusion sheet, it is preferable to use a film composed of a transparent resin coated with a predetermined light diffusion member on both surfaces. The polarizing sheet serves to change the light incident obliquely from among the light incident on the polarizing sheet to be emitted vertically. In addition, the brightness improving sheet transmits light parallel to its transmission axis and reflects light perpendicular to the transmission axis. The transmission axis of such a brightness improving sheet is preferably the same as the polarization axis direction of the polarizing sheet in order to increase the transmission efficiency.

A white LED lamp is used as the light source 210. The light guide plate 220 uses a plate that can change the light in the form of a linear light source into a surface light source. The light guide plate 220 may be disposed above the section display area B of the liquid crystal display panel 100. The reflecting plate 230 is provided on the light guide plate 220 and uses a plate having a high light reflectance. An optical sheet 240 including at least one of a diffusion sheet, a brightness enhancing sheet, and a polarizing sheet is provided between the light guide plate 220 and the section display area B of the liquid crystal display panel 100 and irradiated from the light guide plate 220. The light may be uniformly irradiated onto the liquid crystal display panel 100.

The mold frame 600 is provided with a predetermined protrusion for fixing the liquid crystal display panel 100, and a fixing part 610 to which the light source 210 of the backlight unit 200 is fixed is provided. A predetermined through hole 620 is provided in the 610 so that the light source 210 is introduced into the fixing part 610. And it is effective that the protrusion 630 to be coupled to the receiving member 700 on the outside of the mold frame 600 is provided.

The present invention provides an accommodating member 700 coupled to the mold frame 600. The accommodating member 700 is manufactured in a shape surrounding the side surface of the liquid crystal display panel 100 and the backlight unit 200. As shown in the drawing, it is effective that the housing member 700 of the present embodiment is provided with a through hole 710 corresponding to the protrusion 630 of the mold frame 600.

Here, the mold frame 600 is made of a plastic-based material, and the receiving member 700 is preferably made of a metallic material such as aluminum.

The polarizers 400 and 500 include a third polarizer 400 provided on the lower surface of the liquid crystal display panel 100 and first and second polarizers 500a and 500b provided on the upper surface. In this case, the first polarizing plate 500a is provided on the main display area A, and the second polarizing plate 500b is provided in the section display area B. FIG. The third polarizer 400 and the first polarizer 500a provided in the main display area A use a transmissive polarizer, and the second polarizer 500b provided in the section display area B uses a reflective polarizer. do.

As described above, in the liquid crystal display according to the first exemplary embodiment, the entire liquid crystal display panel 100 is a transmissive type, and the first polarizing plate 500a of the main display area A of the liquid crystal display panel 100 is transmissive. Also, the transmissivity of the main display area A is increased compared to the prior art. In this case, the section display area B uses the second polarizing plate 500b of the section display area B as a reflection type so as to display an image in a direction opposite to the main display area A. Make it look better than before. In addition, as described above, the section display area B of the color filter substrate 120 is manufactured in the same manner as the main display area A, that is, the entire area of the color filter substrate 120 is manufactured in a transmissive manner, thereby making the manufacturing process more conventional. Easy and reduced number of processes can minimize cost burden.

In the liquid crystal display according to the first exemplary embodiment of the present invention having the above-described structure, the second polarizing plate 500b of the section display region B is maximized by maximizing the amount of light by increasing the transmittance by using the section display region B as the section structure. ) Reflects light. However, even in the above structure, the section display area B is hard to see in the dark.

Next, a liquid crystal display according to a second exemplary embodiment of the present invention, in which a section display area is well seen in a dark place, will be described with reference to the drawings. In the following description, a description overlapping with the liquid crystal display according to the first embodiment of the present invention will be omitted.

6 is an exploded perspective view of a liquid crystal display according to a second exemplary embodiment of the present invention, and FIG. 7 is a cross-sectional view taken along line B-B of FIG. 6.

6 and 7, a liquid crystal display according to a second exemplary embodiment of the present invention includes a liquid crystal display panel 100 having a main display area A and a section display area B, and a liquid crystal display panel ( Polarizing plates provided on both sides of the 100 and the backlight unit 200 for irradiating light to the main display area (A). The liquid crystal display panel 100 may further include a mold frame 600 for fixing the backlight unit 200 and an accommodating member 700 for accommodating the liquid crystal display panel 100.

The liquid crystal display panel 100 includes a thin film transistor substrate 110 and a color filler substrate 120. In this case, the thin film transistor substrate is a transparent glass substrate in which a thin film transistor (TFT) and a pixel electrode are formed in a matrix form, and the color filter substrate 120 is colorized in which a predetermined color is expressed while light passes. A sweeping RGB pixel is a substrate formed by a thin film process. The liquid crystal display according to the second exemplary embodiment of the present invention also manufactures the thin film transistor substrate 110 and the color filter substrate 120 in a transmissive manner as in the first exemplary embodiment.

The backlight unit 200 is to supply light to the main display area A of the liquid crystal display panel 100, and is provided on a portion of the lower side of the liquid crystal display panel 100. In this case, the backlight unit 200 includes a light source 210, a light guide plate 220 for irradiating light from the light source 210 to the main display area A of the liquid crystal display panel 100, and the light guide plate 220. A plurality of optical sheets 240 provided on the upper, and the reflecting plate 230 provided below the light guide plate 220.

The polarizers 400 and 500 include a third polarizer 400 provided on the lower surface of the liquid crystal display panel, and first and second polarizers 500a and 500b provided on the upper surface. In this case, the first polarizing plate 500a is provided on the main display area A, and the second polarizing plate 500b is provided in the section display area B. FIG. The polarizing plates 400 and 500 are the same as the liquid crystal display according to the first exemplary embodiment of the present invention, and the third polarizing plate 400 and the first polarizing plate 500a provided in the main display area A are transmissive polarizing plates. Is used, and the second polarizing plate 500b provided in the section display area B uses a reflective polarizing plate.

In this case, the light guide plate 220 extends to the section display area B so as to supply light to the section display area B as well as the main display area A. FIG. Therefore, the light emitted from the light source 210 may not only pass through the main display area A of the liquid crystal display panel 100, but may be reflected by the second polarizing plate 500b of the section display area B. FIG. Therefore, the light reflected by the second polarizing plate 500b passes through the section display area B of the liquid crystal display panel 100 so that the section display area B can be seen even in a dark place.

Although described above with reference to the drawings and embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit of the invention described in the claims below. I can understand.

As described above, the present invention uses a transmissive polarizer for the main screen area and a reflective polarizer for the sub screen area, thereby manufacturing the thin film transistor substrate and the color filter substrate as a transmissive type to increase light transmittance, thereby increasing the overall transparency of the liquid crystal display panel. Optical characteristics can be improved.

In addition, since the present invention manufactures the entire area of the color filter substrate in a transmissive type, the manufacturing process is easy and the number of processes is reduced, thereby minimizing the cost burden.

In addition, the present invention can provide a liquid crystal display device in which the light guide plate is formed not only in the main screen area but also in the sub screen area so that the sub screen area is easily seen even in the dark.

Claims (10)

A liquid crystal display panel comprising a thin film transistor substrate and a color filter substrate in which a first display region and a second display region are defined. And a second polarizing plate provided on one surface of the color filter substrate and provided in the first display area and a second polarizing plate provided in the second display area. The method according to claim 1, The first polarizing plate is a transmissive type liquid crystal display panel. The method according to claim 1, The second polarizing plate is a reflection type liquid crystal display panel. The method according to claim 1, The color filter substrate is a transmissive liquid crystal display panel. The method according to claim 1, And the second display area is a sub screen display area. The method according to claim 1, The first display area of the color filter substrate is a liquid crystal display panel, characterized in that each of the single pixel comprises a sub-pixel of red, green, blue. The method according to claim 1, And the second display area of the color filter substrate includes any one of red, green, and blue subpixels in a single pixel. A liquid crystal display panel comprising a thin film transistor substrate and a color filter substrate having a first display area and a second display area defined therein, the first polarizing plate and the second display provided on one surface of the color filter substrate and provided in the first display area. A liquid crystal display panel provided in the region and including a second polarizing plate which is a reflective polarizing plate; And a backlight unit for supplying light to the liquid crystal display panel. The method according to claim 8, The backlight unit includes a light guide plate and a light source, The light guide plate is provided in the first display area under the liquid crystal display panel. The method according to claim 8, The backlight unit includes a light guide plate and a light source, The light guide plate is provided in the first and second display areas below the liquid crystal display panel.

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