KR20110032340A - Liquid crystal display module and display device using the same - Google Patents

Abstract

PURPOSE: A liquid crystal display module, in which white is observed in all viewing angle directions, and a display device using the same are provided to display white the same color as a case color due to reducing the change of a refractive index according to the viewing angle. CONSTITUTION: A liquid crystal panel(101) is included. A backlight assembly(102) arranged in the lower part of the liquid crystal panel is included. A first electrode(104) is formed on the top of the liquid crystal panel. A second electrode(105) is formed on the top of the first electrode. The light of an ultraviolet ray is reflected when a first electrode and a second electrode are formed in a planar shape. A cholesteric liquid crystal layer diffuses the light.

Description

Liquid crystal display module and display device using same {LIQUID CRYSTAL DISPLAY MODULE AND DISPLAY DEVICE USING THE SAME}

The present invention relates to a liquid crystal display module and a display device using the same, wherein a liquid crystal having high quality in appearance by unifying the color of the screen of the display module and the case surrounding the outside of the display module when the display module is turned off. A display module and a display device using the same.

In general, a mobile communication device such as a portable computer, a mobile phone, a personal digital assistant, etc. is provided with a display module for displaying a screen including a main body, such as a liquid crystal display having advantages such as small size, light weight and low power consumption. The adoption of modules is on the rise.

The liquid crystal display module displays a desired image on the screen by adjusting the amount of light transmitted according to the image signals applied to the plurality of control switching elements arranged in a matrix form.

The liquid crystal display module has a liquid crystal panel in which a color filter substrate as an upper substrate and a thin film transistor array substrate as a lower substrate are opposed to each other, and a liquid crystal layer is formed between the two substrates, and a scan signal and image information are supplied to the liquid crystal panel to provide a liquid crystal. It comprises a drive unit for operating the panel.

The liquid crystal display module having the above configuration is a non-light emitting device which does not emit light by itself compared to a cathode ray tube (CRT) or a light emitting diode (LED), so that light is applied to the liquid crystal panel to implement an image. It requires a backlight assembly to supply.

Hereinafter, a mobile communication device equipped with a conventional liquid crystal display module will be described with reference to the accompanying drawings. In describing such a conventional technology, a mobile phone is an example of a mobile communication device.

As shown in FIG. 1, the general mobile phone 1 includes a main body 3 and a display unit 2 on which information transmitted from the main body 3 is displayed.

The main body 3 includes a driving unit (not shown), a keypad 3a, and a cover 3b for driving the entire mobile phone, and the display unit 2 is a liquid crystal display module 2a which is a means for displaying a screen. A keypad 2b and a cover 2c are provided.

FIG. 2 is a cross-sectional view of a conventional general liquid crystal display module 2a provided as a component of the display unit 2 of the mobile phone 1. Referring to FIG. 2, the conventional general liquid crystal display module 2a is illustrated. The liquid crystal panel 11 is composed of a color filter substrate 11a, which is an upper substrate, and a thin film transistor array substrate 11b, which is a lower substrate, and a liquid crystal layer 11c is formed between the first and second substrates 11a and 11b. ) And a backlight assembly 12 disposed under the liquid crystal panel 11 to supply light to the liquid crystal panel 11.

Recently, the conventional mobile phone 1 having the above-described configuration has the upper surface of the liquid crystal panel 11 so that the screens of the covers 2c and 3b and the liquid crystal panel 11 can have the same color when the mobile phone 1 is in an open state. A configuration was formed in which a quarter wave plate (QWP) 14 and a cholesteric liquid crystal layer 15 were sequentially formed.

The cholesteric liquid crystal layer 15 is formed to have a planar structure. In particular, the cholesteric liquid crystal layer 15 has a characteristic of selectively reflecting specific circularly polarized light (one selected from left circularly polarized light and right circularly polarized light) of a specific wavelength and transmitting all remaining light. In this case, the liquid crystal panel 11 is set to display a color having a specific wavelength, that is, the same color as the covers 2c and 3b when the liquid crystal panel 11 is not driven.

In addition, the retardation plate 14 is formed to have a function of changing the rotation direction of a specific circularly polarized light having a specific wavelength reflected by the cholesteric liquid crystal layer 15 in the opposite direction, so that the liquid crystal panel 11 is driven. In this state, all the light passing through the retardation plate 14 passes through the cholesteric liquid crystal layer 15 so that the user can observe the image that the liquid crystal panel 11 intends to display.

However, in the mobile phone 1 as described above, the cholesteric liquid crystal layer 15 has a very different color characteristic according to the viewing angle when forming the planar structure, so that the cover when the mobile phone 1 is observed in the front viewing angle direction Although the screen colors are the same as those of (2c, 3b), when the mobile phone 1 is observed in the side viewing angle direction, the screen is changed to a color different from that of the covers 2c and 3b, thereby deteriorating the appearance quality.

In the display device as described above, the cholesteric liquid crystal layer 15 has a very narrow range of wavelengths to be reflected when forming a planar structure. Therefore, when the covers 2c and 3b are white, the liquid crystal panel 11 There is a drawback that the screen cannot be displayed white when the) is not driven.

Accordingly, the present invention is to solve the above problems, the object of the present invention is that the white screen is observed while the LCD panel is not driven in the model of the case is white white at the same time viewing angle direction appearance It is to provide a liquid crystal display module with improved quality and a display device using the same.

Liquid crystal display module according to an embodiment of the present invention for performing the above object, the liquid crystal panel; A backlight assembly disposed under the liquid crystal panel; A first electrode formed on the liquid crystal panel; A second electrode formed on the first electrode; And an ultraviolet (UV) range formed between the first electrode and the second electrode, and removed after the first and second voltages are applied to each of the first and second electrodes to form a planar structure. Cholester which reflects light and transmits the remaining light, and is removed after the third and fourth voltages are applied to each of the first and second electrodes to form a focal conic structure. Cholesteric liquid crystal layer; And a control unit.

In addition, a display device according to an exemplary embodiment of the present invention for performing the above object, the case is formed with an opening; A display module disposed inside the case to display an image to the outside through an opening of the case; A first electrode formed on the display module; A second electrode formed on the first electrode; And an ultraviolet (UV) range formed between the first electrode and the second electrode, and removed after the first and second voltages are applied to each of the first and second electrodes to form a planar structure. Cholester which reflects light and transmits the remaining light, and is removed after the third and fourth voltages are applied to each of the first and second electrodes to form a focal conic structure. Rick liquid crystal layer; And a control unit.

The liquid crystal display module and the display module using the same according to an exemplary embodiment of the present invention having the above-described configuration supply a third voltage and a fourth voltage to each of the first electrode and the second electrode when the display module is not driven. After the removal, the light scattering is induced to display a white screen, thereby displaying the same white screen as the case of the display module, so that at least the front surface of the display device is white.

This has the effect of improving the quality of appearance.

The liquid crystal display module and the display module using the same according to an exemplary embodiment of the present invention are removed after the third voltage and the fourth voltage are supplied to the first electrode and the second electrode when the display module is not driven. Since the cholesteric liquid crystal layer constituting the focal conic structure has a very small change in refractive index according to the viewing angle, the screen when viewing the display device in the front viewing angle direction and the viewing device in the lateral viewing angle direction are displayed. There is an advantage that can represent the same white as the color.

Accordingly, there is an effect that no color change problem occurs along the viewing angle direction.

Hereinafter, a liquid crystal display module and a display device using the same according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 3, a display device according to an exemplary embodiment of the present invention includes a case (not shown) having an opening portion; A display module 103 disposed inside the case to display an image to the outside through an opening of the case; A first electrode 104 formed on the display module 103; A second electrode 105 formed on the first electrode 104; And a first voltage and a second voltage formed between the first electrode 104 and the second electrode 105, and then removed after the first voltage and the second voltage are applied to each of the first electrode 104 and the second electrode 105. The planar structure reflects light in the ultraviolet (UV) range and transmits the remaining light, and is removed after the third and fourth voltages are applied to each of the first electrode 104 and the second electrode 105. A cholesteric liquid crystal layer 106 for scattering light when forming a focal conic structure; .

Each component of the display device according to an exemplary embodiment of the present invention having such a configuration will be described in detail as follows.

Although not shown in detail in the drawings, the display device according to the preferred embodiment of the present invention includes a case (not shown) having an opening portion for exposing an image of the display module 103 disposed therein to the outside. In this case, at least the area adjacent to the opening part has a white color.

Referring to FIG. 3, the display module 103 is a liquid crystal display including a liquid crystal panel 101 and a backlight assembly 102.

The liquid crystal panel 101 includes a color filter substrate 101a as an upper substrate and a thin film transistor array substrate 101b as a lower substrate, and includes a liquid crystal layer (B) between the two substrates 101a and 101b of the liquid crystal panel 101. 101c) is formed.

The backlight assembly 102 includes a light source, a light guide plate, an optical sheet, and a reflective sheet. The light source may be a fluorescent lamp or a light emitting diode as a means for supplying light to the liquid crystal panel, the light guide plate changes the traveling path of the light from the light source to guide the direction of the liquid crystal panel, the optical sheet from the light guide plate The light is diffused and collected and supplied to the liquid crystal panel, and the reflective sheet reflects the light leaking into the lower part of the light guide plate into the light guide plate. Such a backlight assembly may be configured in addition to the above configuration if necessary.

In the description of the display device according to the preferred embodiment of the present invention, the liquid crystal display device including the liquid crystal panel 101 and the backlight assembly 102 is employed as the display module 103. The present invention is not limited thereto, and a display module other than a liquid crystal display device may be used as the display module.

In the display module 103, a first electrode 104 is formed on the liquid crystal panel 101, a second electrode 105 is formed on the first electrode 104, and the first electrode ( The cholesteric liquid crystal layer 101c is formed between the 104 and the second electrode 105.

The cholesteric liquid crystal layer 106 is a planar structure when the first voltage and the second voltage are applied to each of the first electrode 104 and the second electrode 105 for a predetermined time, and then removed. Reflects light in the UV range and transmits light in the remaining wavelengths, and is removed after the third and fourth voltages are applied to each of the first electrode 104 and the second electrode 105 for a predetermined time. The arrangement is altered to achieve a focal conic structure and set to scatter light. In this case, it is preferable that the voltage difference between the first voltage and the second voltage is a sufficient voltage such that the liquid crystals of the cholesteric liquid crystal layer 106 can be arranged vertically, and the voltage difference between the third voltage and the fourth voltage is cholesteric. It is preferable that the voltage is such that the liquid crystals of the liquid crystal layer 106 are not arranged vertically. That is, the voltage difference between the first voltage and the second voltage is preferably greater than the voltage difference between the third voltage and the fourth voltage. For example, the voltage difference between the first voltage and the second voltage is a high voltage of 40 [V] or more. The voltage difference between the third voltage and the fourth voltage is 40 [V] or less.

The cholesteric liquid crystal layer 106 will be described in detail with reference to FIGS. 4 to 7 as follows.

4 shows that the cholesteric liquid crystal layer 106 has a planar structure by removing the first voltage and the second voltage applied to each of the first electrode 104 and the second electrode 105 for a predetermined time and then removing the electric field. FIG. 5 illustrates that the cholesteric liquid crystal layer 106 is removed after the first voltage and the second voltage are applied to each of the first electrode 104 and the second electrode 105 for a predetermined time. By forming the planar structure, the image of the display module 103 is photographed by reflecting the light in the ultraviolet range and transmitting the light of the remaining wavelengths. The first electrode 104 and the second electrode are shown in FIG. A third voltage and a fourth voltage are applied to each of the electrodes 105 for a predetermined time, and when the electric field is formed, the cholesteric liquid crystal layer 106 forms a focal conic structure. Each of the first electrode 104 and the second electrode 105 The pictures taken on a display a state that a white screen is removed by the third voltage and the fourth voltage is applied for a predetermined time after the light scattering focal conic structure by yirum the liquid crystal layer 106. The cholesteric rigs.

Referring to FIG. 4, the liquid crystal forming the cholesteric liquid crystal layer 106 is removed after the first and second voltages are applied to each of the first electrode 104 and the second electrode 105 to form an electric field. When the planar structure is formed, the spiral axis has a spiral structure oriented so that the spiral axis is substantially perpendicular to the substrate surface, and the pitch, which is the repetition period of the spiral, is set to reflect light in the ultraviolet range.

As described above, since the cholesteric liquid crystal layer 106 has a planar structure, only the light in the ultraviolet range is reflected and the light in the remaining wavelengths is transmitted. Thus, the cholesteric liquid crystal layer 106 emits light in the visible range. In this case, when the display module 103 is driven to display an image, the cholesteric liquid crystal layer on the display module 103 is formed when the cholesteric liquid crystal layer 106 has a planar structure. Even if 106 exists, the user can observe the image displayed by the display module 103 without any problem.

That is, the display device according to the exemplary embodiment of the present invention is removed after applying the first voltage and the second voltage to each of the first electrode 104 and the second electrode 105 when the display module 103 is driven. As a result, the cholesteric liquid crystal layer 106 has a planar structure to allow light within the visible light range to be transmitted, thereby allowing a user to observe an image displayed by the display module 103 as shown in FIG. 5.

Referring to FIG. 6, the liquid crystal constituting the cholesteric liquid crystal layer 106 is removed after the third and fourth voltages are applied to each of the first electrode 104 and the second electrode 105 to form an electric field. In the case of forming a focal conic structure, a domain is locally formed to generate rayleigh scattering of light due to a difference in refractive index at the boundary of the domain, thereby displaying white.

As described above, when the cholesteric liquid crystal layer 106 forms a focal conic structure, a domain is locally formed to generate Rayleigh scattering to display white color. Thus, when the display module 103 is not driven, the cholesteric liquid crystal layer 106 does not operate. When the 106 forms a focal conic structure, a white screen is displayed as shown in FIG. 7 to show the same color as a white case (not shown), so that at least the front surface of the display device is all white, thereby improving appearance quality.

That is, in the display device according to the exemplary embodiment of the present invention, when the display module 103 is not driven, the third voltage and the fourth voltage are applied to each of the first electrode 104 and the second electrode 105 for a predetermined time. By applying and removing the electric field after forming, the cholesteric liquid crystal layer 106 has a focal conic structure so that the light is scattered and scattered so that the user can observe the same white screen as the white case.

In the display device according to the preferred embodiment of the present invention having the above-described configuration, the cholester which reflects light in the ultraviolet range when transmitting the planar structure, transmits the remaining light, and scatters the light when forming the focal conic structure. The first electrode 104 and the second electrode having a lick liquid crystal layer 106 and forming an electric field in the cholesteric liquid crystal layer 106 when the display module 103 is not driven to form a focal conic structure. By providing the 105, when the display module 103 is not driven, the light scattering is eliminated by supplying a third voltage and a fourth voltage to each of the first electrode 104 and the second electrode 105, and then removing them. By inducing a white screen to display the white screen that is the same as the color of the case of the display module 103 so that at least the front surface of all of the display device is white to improve the appearance quality.

In the display device according to the preferred embodiment of the present invention, the cholesteric liquid crystal layer 106 arranged to form a focal conic structure when the display module 103 is not driven has a change in the refractive index according to the viewing angle. Since the display is very small, the screen may display the same white color as the case color when the display device is viewed from the front viewing angle direction and the display device is viewed from the side viewing angle direction. The effect is that no change problem occurs.

1 is a perspective view showing a conventional general mobile phone.

FIG. 2 is a cross-sectional view illustrating a liquid crystal display module, a retardation plate, and a cholesteric liquid crystal layer included in the display device of FIG. 1. FIG.

3 is a cross-sectional view illustrating a part of a display device according to an exemplary embodiment of the present invention.

4 is a cross-sectional view showing a state in which the cholesteric liquid crystal layer of FIG. 3 forms a planer structure.

5 is a photograph of a state in which an image of a display module is displayed to the outside by transmitting light in the visible range when the cholesteric liquid crystal layer of FIG. 3 forms a planar structure.

FIG. 6 is a cross-sectional view illustrating the cholesteric liquid crystal layer of FIG. 3 forming a focal conic structure. FIG.

FIG. 7 is a photograph of a state in which a white screen is displayed by scattering light when the cholesteric liquid crystal layer of FIG. 3 forms a focal conic structure. FIG.

** Description of the symbols for the main parts of the drawings **

101: liquid crystal panel 102: backlight assembly

103: display module 104: first electrode

105: second electrode 106: cholesteric liquid crystal layer

Claims (11)

A liquid crystal panel; A backlight assembly disposed under the liquid crystal panel; A first electrode formed on the liquid crystal panel; A second electrode formed on the first electrode; And It is formed between the first electrode and the second electrode, and is removed after the first voltage and the second voltage is applied to each of the first electrode and the second electrode to form a planar structure in the ultraviolet (UV) range A cholesteric that reflects light and transmits the remaining light, and is removed after the third and fourth voltages are applied to each of the first and second electrodes to form a focal conic structure. Liquid crystal layer; Liquid crystal display module comprising a. The cholesteric liquid crystal layer of claim 1, wherein when the liquid crystal panel is turned on, the cholesteric liquid crystal layer forms a planar structure after the first voltage and the second voltage are applied to each of the first electrode and the second electrode. When the liquid crystal panel is turned off, the third and fourth voltages are applied to the first electrode and the second electrode, and then removed, thereby removing the cholesteric liquid crystal layer. . The liquid crystal display module of claim 2, wherein the voltage difference between the first voltage and the second voltage is greater than the voltage difference between the third voltage and the fourth voltage. The liquid crystal display module as claimed in claim 1, wherein the cholesteric liquid crystal transmits light in the visible range when forming a planar structure, so that a user can observe an image displayed on the liquid crystal panel. The liquid crystal display module of claim 1, wherein the cholesteric liquid crystal displays white color by scattering light when forming a focal conic structure, such that the user observes a white screen. A case in which an opening is formed; A display module disposed inside the case to display an image to the outside through an opening of the case; A first electrode formed on the display module; A second electrode formed on the first electrode; And It is formed between the first electrode and the second electrode, and is removed after the first voltage and the second voltage is applied to each of the first electrode and the second electrode to form a planar structure in the ultraviolet (UV) range A cholesteric that reflects light and transmits the remaining light, and is removed after the third and fourth voltages are applied to each of the first and second electrodes to form a focal conic structure. Liquid crystal layer; Display device, characterized in that configured to include. The display device of claim 6, wherein the case is white. The cholesteric liquid crystal layer of claim 6, wherein when the display module is turned on, the cholesteric liquid crystal layer forms a planar structure after the first voltage and the second voltage are applied to each of the first electrode and the second electrode. And when the display module is turned off, the third and fourth voltages are applied to each of the first electrode and the second electrode, and then removed to form a focal conic structure. The display device of claim 8, wherein the voltage difference between the first voltage and the second voltage is greater than the voltage difference between the third voltage and the fourth voltage. The display apparatus of claim 6, wherein the cholesteric liquid crystal transmits light in a visible range when forming a planar structure, so that a user may observe an image displayed on a display module. The display device of claim 6, wherein the cholesteric liquid crystal displays white color by scattering light when forming a focal conic structure, such that the user observes a white screen.

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